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FOOD PRESERVATIVES THOSE ARE COMMONLY
USED IN FOOD & BEVERAGE INDUSTRY
PREPARED BY: SHARJIL MAHMOOD
MS Fellow in Food Chemistry & Chemical Assurance
Chittagong Veterinary & Animal Sciences University
E-MAIL: smah.sm67@gmail.com
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INTRODUCTION
A food preservative is a natural or synthetic chemical that is added to foods or pharmaceuticals
to retard spoilage, whether from microbial growth, or undesirable chemical changes. Some
methods of food preservation involve the use of salt, sugar or vinegar, which are sometimes
considered to be foods rather than additives. Some people believe preservatives are harmful.
Food preservatives have been around since centuries ago, as in pickled onions, salted meat and
fish, sweetened fruit and spiced foods. As people move away from the countryside and demand
for food increased many people rely on processed items as part of their daily sustenance. Foods
preservatives help maintain the freshness and shelf life of such food products because without
them, they would spoil quickly due to exposure to air, moisture, bacteria, or mould. Either
natural or synthetic substances may be added to avoid or delay these problems.
Food preservatives, spices, and flavoring agents have been added to foods for thousands of years.
These compounds which are added to foods are termed as food additives. Chemical food
preservatives are applied to foods as direct additives during processing, or develop by themselves
during processes such as fermentation.
Food additives can be defined as the Substance or mixture of substance, other than a basic
foodstuff which is present in food as result of any aspect of production, processing, storage or
packaging. This definition does not include any chemicals that are contaminants pesticides, color
additives or new animal drugs.
HISTORY OF PRESERVATIVES
Preservatives have been used since prehistoric times. Smoked meat for example has phenols and
other chemicals that retard spoilage. The preservation of foods has evolved greatly over the
centuries, and has been instrumental in increasing food security. The use of preservatives other
than traditional oils, salts, etc. in food began in the late 19th century, but was not widespread
until the 20th century.
IMPORTANCE OF PRESERVATIVES
 Maintain consistency and texture: Preservatives sustain smoothness or prevent the food
from separating, caking, or clumping. Preservatives slow product spoilage caused by mold,
air, bacteria, fungi or yeast. In addition to maintaining the quality of the food, they help
control contamination that can cause food borne illness, including life-threatening botulism.
 Improve or retain nutritional properties: During preparation process of food some
vitamins and minerals are being subjected to destruction. Fortification adds a nutrient that
wasn't there before and may be lacking in many people's diets.
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 Delay spoilage: Preservation usually involves preventing the growth of bacteria, fungi (such
as yeasts), and other microorganisms, as well as retarding the oxidation of fats which cause
rancidity.
 Enhance flavors, textures, and color: Spices, natural and artificial flavors and sweeteners
are added to enhance the taste of food. Food colors maintain or improve appearance.
Emulsifiers, stabilizers and thickeners give foods the texture and consistency consumers
expect. Leavening agents allow baked goods to rise during baking. Some preservatives help
control the acidity and alkalinity of foods, while other ingredients help maintain the taste and
appeal of foods with reduced fat content.
TYPES OF PRESERVATIVES
1. Natural or Class One Food Preservatives
In the category of natural food preservatives comes the salt, sugar, alcohol, vinegar etc. These
are the traditional preservatives in food that are also used at home while making pickles, jams
and juices etc. Also the freezing, boiling, smoking, salting are considered to be the natural ways
of preserving food. Coffee powder and soup are dehydrated and freeze-dried for preservation. In
this section the citrus food preservatives like citrus acid and ascorbic acid work on enzymes and
disrupt their metabolism leading to the preservation. Sugar and salt are the earliest natural food
preservatives that very efficiently drop the growth of bacteria in food. To preserve meat and fish,
salt is still used as a natural food preservative.
Natural preservatives can be classified into:
 Plants with natural antimicrobial activities
Onion (Allium cepa, L.): Good source of bioactive compounds, such as sulphur containing
Compounds and flavonoids. Antimicrobial activity of onion is due to thiosulfinates and other
volatile organic compounds and shown inhibition against gram positive and gram negative
bacteria. Onion anti yeast, anti-fungal activity is due to presence of organosulfur-containing
compounds which inhibit the growth of yeast and fungi.
Cardamom (E.Cardamomum): Essential oil is derived from different plant parts of cardamom
such as flowers, leaves, stem, barks etc. Extraction methods are supercritical fluid extraction,
solvent extraction, hydrodistillation, steam distillation.
It contains bioactive components like 1-8 cineole, terpinyl acetate, phenolics, and limonene etc.
possesses antimicrobial activities and inhibits the growth of bacteria, virus, fungi, and molds. On
the contrary, Essential oils have antioxidants phenolics and flavonoids which is used as natural
antioxidants.
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 Antimicrobials from animals
Lactoperoxidase: Basically Lactoperoxidase Glycoprotein with high isoelectric point and one
Fe group which occurs in milk, saliva and tears of many mammals.Basic Function of
lactoperoxidase is to oxidize thiocynate and some halides to generate products and affects the
cytoplasmic membrane that kill or inhibit growth of microorganisms.
Furthermore its exert bacteriostatic effect on Listeria, Staphylococcus and in the addition of LP
to starter culture for yogurt production inhibited the acid production and new yogurt produced
with extended shelf life Used in oral care products toothpaste and Preservative in ground beef
products.
Chitosan: Natural biopolymer obtained from the exoskeletons of crustaceans (crabs and shrimp)
and arthropods used as active material for its antifungal activity and antibacterial activity.
Liu et al. studied the efficacy of chitosan against E. coli and concluded that low molecular
weight chitosan is effective for controlling growth. The strong antibacterial activity of chitosan
was also observed against S. aureus.
Chitosan coating was formed by dipping the products in a chitosan–lactic acid/Na-lactate
solution and pH adjusted. Several bacteria and yeast were exposed to chitosan concentrations
varying from 40 to 750 mg/l. Gram-negative bacteria seemed to be very sensitive for the applied
chitosan (MIC< 0.006% (w/v)) The antimicrobial effect of chitosan were observed on
strawberries during 12 days.
 Antimicrobials from micro organism
Nisin: Only natural antimicrobial peptide approved by the FDA to use as a food preservative
obtained from the culturing of L. lactis on natural substrates. Nisin is soluble in water and 100 &
300 IU/g decrease growth of L.monocytogens, S.aureus functions by interacting with the
phospholipids in the cytoplasmic membrane of bacteria, thus disrupting membrane function and
preventing outgrowth of spores.
Nisin is highly active against many of the Gram-positive bacteria which can be completely
degraded in alimentary tract so safe to use. Beside this, nisin is used as a food preservative in a
number of thermal processed foods, particularly in dairy products, canned foods, plant protein
foods and cured meat products and marine products.
Natamycin: Which is also known as Pimaricin, produced by a pure culture of Streptomyces
natalensis bacteria through fermentation process. Target ergosterol in the cell wall, a building
block of yeasts and molds which is responsible for intracellular nutrient transport. Natamycin is
very effective at very low levels and is approved in different applications with different level in
the world.
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2. Chemical or class two preservatives:
Chemical food preservatives have also been used for quite some time now. They seem to be the
best and the most effective for a longer shelf life and are generally food proof for the
preservation purpose. These food preservatives are the chemical substances that:
 Stop or delay the growth of bacteria and spoilage
 Keep foods from becoming rancid or developing black spots
 Suppress the reaction when food comes in contact with oxygen,
 Heat, and some metals prevent the loss of some essential amino-acids and some vitamins
 Enhance the food flavors and colors
These artificial preservatives can be added to the food or sprayed on the food.
Chemical Preservatives can be depicted as follows:
 Antimicrobial agents
They inhibit the activity of or kill the bacteria, molds, insects and other microorganisms.
Antimicrobial agents those are commonly used in foods are-
a) Benzoates:
This group of chemical food preservative has been banned in Russia because of its role in
triggering allergies, asthma and skin rashes. It is also considered to cause brain damage. This
food preservative is used in fruit juices, tea and coffee.
In case of sodium benzoates, which is a common type of food preservative and is the sodium
salt of benzoic acid. Food manufacturers make sodium benzoate by synthesizing the compounds,
sodium hydroxide and benzoic acid, together. In addition to its use as a food preservative,
sodium benzoate has other roles in food production as well. There are some side effects
associated with excess sodium benzoate consumption in foods, so talk with your doctor about it
to make sure you are not ingesting harmful doses of preservatives.
Structure:
Molecular formula: C7H5O2Na
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Mechanism: Sodium benzoate preserves food by having anti-fungal properties, protecting foods
from invasion by fungi that cause food to spoil and potentially make you sick. Sodium benzoate
works by entering the individual cells in the food and balancing its pH level, increasing the
overall acidity of the food. By lowering the intracellular pH of certain foods, sodium benzoate
creates an environment in which fungi cannot grow and spread. According to the International
Program on Chemical Safety, sodium benzoate is heavily used by the soft drink industry due to
the demand of high-fructose corn syrup in carbonated drinks. Sodium benzoate increases the
acidity of soft drinks, which also increases the intensity of flavor you get from the high-fructose
corn syrup. On the back of a soda can, you can find sodium benzoate in the ingredients list as
E211, which is the number assigned to it as a food additive.
On the other hand, Sodium benzoate is primarily added to acidic foods to enhance their flavor. It
can be found in foods such as pickles, sauces, jams and fruit juices. Foods that contain vinegar,
such as salad dressings, typically contain very high levels of sodium benzoate. Benzene, a
precursor to sodium benzoate, can be found in very small amounts naturally in some fruits,
vegetables, meats, dairy products and even drinking water.
Health effect: taking sodium benzoate and sodium phenylacetate may result in more severe side
effects, including severe bruising, blood in the stools or urine, vomiting blood, difficulty
breathing or changes in breathing patterns, drowsiness or unconsciousness. Additional rare side
effects include muscle cramps, tremors, rash, restlessness and a feeling of tightness in the chest.
1. Sorbates: such as Sodium sorbate, Potassium sorbate.
Potassium sorbate originates from the potassium salt of sorbic acid, which is naturally found in
many plants, and prevents the growth of pathogens. According to the Center for Science in
Public Interest, the additive is safe to consume.
Structure:
Molecular Formula: C6H7O2K
Mechanism: It’s also known as wine stabilizer", potassium sorbate produces sorbic acid when
added to wine. It serves two purposes. When active fermentation has ceased and the wine is
racked for the final time after clearing, potassium sorbate renders any surviving yeast incapable
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of multiplying. Yeast living at that moment can continue fermenting any
residual sugar into CO2 and alcohol, but when they die, no new yeast will be present to cause
future fermentation. When a wine is sweetened before bottling, potassium sorbate is used to
prevent refermentation when used in conjunction with potassium metabisulfite. It is primarily
used with sweet wines, sparkling wines, and some hard ciders, but may be added to table wines,
which exhibit difficulty in maintaining clarity after fining.
Health effect: Long term dietary intake of potassium sorbate can cause nutritional deficiencies,
those results in the body does not absorb nutrients, vitamin and minerals properly. Digestive
problems can often lead to nutritional deficiencies.
2. Nitrites: such as Sodium nitrite,
Commonly used as preservative for ham, bacon, sausages and bologna, it gets converted into
nitrous acid when consumed and is suspected of inciting stomach cancer. Germany and Norway
have banned the use of this harmful food preservative after declaring it a toxin.
Structure:
Molecular formula: NaNO2
Mechanism: Sodium nitrite is well known for its role in inhibiting the growth of Clostridium
botulinum spores in refrigerated meats. The mechanism for this activity results from the
inhibition of iron-sulfur clusters essential to energy metabolism of Clostridium botulinum.
However, sodium nitrite has had varying degrees of effectiveness for controlling growth of other
spoilage or disease causing microorganisms. Even though the inhibitory mechanisms for sodium
nitrite are not well known, its effectiveness depends on several factors including residual nitrite
level, pH and salt concentration, reductants present and iron content. Furthermore, the type
of bacteria also affects sodium nitrites effectiveness. It is generally agreed upon that sodium
nitrite is not considered effective for controlling negative enteric pathogens such
as Salmonella and Escherichia coli.
 Antioxidants
Antioxidants are beneficial in preventing rancidity in fats and foods containing fats. Fats exposed
to light, moisture, heat or heavy metal ions become activated and oxidize (reach with available
oxygen) to peroxides. Antioxidants are chemical food preservatives that act as free radical
scavengers. The most used antioxidants are Butylated Hydroxy Anisole (BHA), Butylated
Hydroxy Toluence (BHT), Propyl Gallate, Natural/Synthetic Tocopherols (Vitamin E) Ascorbic
Acid (vitamin C) and Lecithin.
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a) Butylated Hydroxy Anisole (BHA)
The common food preservatives for fruits, dried fruits, canned olives and
cornstarch, wine vinegar, and wine have side effects in form of headaches, joint pain, heart
palpitations, allergies, and cancer.
stable even at high temperatures compared to other
claimed to be natural. This is one of the biggest reasons why food industry experts suggest using
Butylated Hydroxyanisole & Butylated hydroxytoluene
Structure: BHA-
Molecular Formula: C11 H16 O
How do they preserve food: BHA and BHT are antioxidants. Oxygen reacts p
BHA or BHT rather than oxidizing
to being oxidizable, BHA and BHT are fat
salts. In addition to preserving foods, BHA and BHT are also used to preserve fats and oils in
cosmetics and pharmaceuticals.
Effects on health: BHA and BHT
effects. The research leads to conflicting conclusions. The o
metabolites of BHA and BHT may contribute to carcinogenicity or tumorigenicity
b) Ascorbic Acid:
Ascorbic acid is a chemical compound that is commonly found in
an antioxidant food additive. Ascorbic acid is a vitamer of Vitamin C, which means it is a
compound that provides the same vitamin activity as Vitamin C. Often
compounds that produce the same activity of one vitamin and they are often called by that
vitamin's name. Ascorbic acid is found in nature in many fruits and vegetables (especially citrus
fruits and peppers) and is also produced by the kid
produce ascorbic acid and must obtain it from the diet, or else they will develop a deficiency and,
in more severe cases, scurvy. Industrially, ascorbic acid is produced through a multistep process
involving bacteria that reduce glucose and produce ascorbic acid as a byproduct.
Ascorbic acid can be used in a variety of forms, including
appear on ingredient lists under different names, such as sodium ascorbate, calcium ascorbate,
potassium ascorbate, ascorbyl palmitate, or ascorbyl stearate.
Anisole (BHA) & Butylated Hydroxytoluene (BHT):
he common food preservatives for fruits, dried fruits, canned olives and peppers, corn syrup,
cornstarch, wine vinegar, and wine have side effects in form of headaches, joint pain, heart
palpitations, allergies, and cancer. The largest advantage of BHA & BHT is that, it remains
stable even at high temperatures compared to other preservatives and additives, which are merely
claimed to be natural. This is one of the biggest reasons why food industry experts suggest using
Butylated hydroxytoluene.
BHT-
O2 C15H24O2
BHA and BHT are antioxidants. Oxygen reacts preferentially with
oxidizing fats or oils, thereby protecting them from spoilage.In addition
to being oxidizable, BHA and BHT are fat-soluble. Both molecules are incompatible with ferric
salts. In addition to preserving foods, BHA and BHT are also used to preserve fats and oils in
BHA and BHT are excellent preservatives may also be implicated in health
The research leads to conflicting conclusions. The oxidative characteristics and/or
metabolites of BHA and BHT may contribute to carcinogenicity or tumorigenicity
Ascorbic acid is a chemical compound that is commonly found in nature and can be used as
Ascorbic acid is a vitamer of Vitamin C, which means it is a
compound that provides the same vitamin activity as Vitamin C. Often
compounds that produce the same activity of one vitamin and they are often called by that
Ascorbic acid is found in nature in many fruits and vegetables (especially citrus
fruits and peppers) and is also produced by the kidney of some animals. Humans are not able to
produce ascorbic acid and must obtain it from the diet, or else they will develop a deficiency and,
in more severe cases, scurvy. Industrially, ascorbic acid is produced through a multistep process
eria that reduce glucose and produce ascorbic acid as a byproduct.
Ascorbic acid can be used in a variety of forms, including salts and esters. In these forms, it will
redient lists under different names, such as sodium ascorbate, calcium ascorbate,
potassium ascorbate, ascorbyl palmitate, or ascorbyl stearate.
:
peppers, corn syrup,
cornstarch, wine vinegar, and wine have side effects in form of headaches, joint pain, heart
is that, it remains
preservatives and additives, which are merely
claimed to be natural. This is one of the biggest reasons why food industry experts suggest using
referentially with
fats or oils, thereby protecting them from spoilage.In addition
molecules are incompatible with ferric
salts. In addition to preserving foods, BHA and BHT are also used to preserve fats and oils in
ay also be implicated in health
xidative characteristics and/or
metabolites of BHA and BHT may contribute to carcinogenicity or tumorigenicity.
nature and can be used as
Ascorbic acid is a vitamer of Vitamin C, which means it is a
compound that provides the same vitamin activity as Vitamin C. Often there is several
compounds that produce the same activity of one vitamin and they are often called by that
Ascorbic acid is found in nature in many fruits and vegetables (especially citrus
ney of some animals. Humans are not able to
produce ascorbic acid and must obtain it from the diet, or else they will develop a deficiency and,
in more severe cases, scurvy. Industrially, ascorbic acid is produced through a multistep process
eria that reduce glucose and produce ascorbic acid as a byproduct.
and esters. In these forms, it will
redient lists under different names, such as sodium ascorbate, calcium ascorbate,
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Structure:
Molecular Formula: C6H8O6
Ascorbic Acid Used in Food:
provide multiple benefits to food products
Slowing the oxidation preserves color (cut apples and avocados brown when they come into
contact with oxygen) and it preserves the freshness. The low pH of ascorbic acid can help
prevent microbial growth, thereby preventing spoilage and preserving freshness. For these
reasons, ascorbic acid is a popular natural ingredient preservative.
It can be used as a preservative in
jams and jellies, and other sauces and
an excellent ingredient for vitamin supplementation. Simply adding ascorbic acid to food
increases the Vitamin C content. Since naturally occurring Vitamin C is easily destroyed, many
foods are fortified with ascorbic acid to replenish the Vitamin C content. Ascorbic acid is often
added to fruit juices, dried fruit, cereal, and other snack foods for
 Chelating Agent
Chelating or sequestering agents protect food products from many enzymatic reactions that
promote spoilage during processing and storage. These agents bind to many of the minerals that
are present in foods (e.g. calcium and magnesium) and are required as cofactors for the activity
of certain enzymes.
a) Disodium ethylenediaminetetraacetic acid
EDTA is one of the most commonly used preservatives for a number of packaged foods; it has
multiple negative impacts and associated allergy and reaction cases. Though use in a lot of food
products and cosmetics it is known to cause skin allergies and reactions, besides aggravated
asthma problems and kidney damage.
Edetic Acid is the acid form of
anticoagulant properties. Edetic acid
complexes which are readily excreted by the kidneys. This
serum calcium levels. This agent is also used as an anticoagulant for blood specimens and is
applied as a treatment of lead poisoning
Ascorbic acid is used primarily as an antioxidant,
food products.
Slowing the oxidation preserves color (cut apples and avocados brown when they come into
preserves the freshness. The low pH of ascorbic acid can help
prevent microbial growth, thereby preventing spoilage and preserving freshness. For these
reasons, ascorbic acid is a popular natural ingredient preservative.
It can be used as a preservative in a vast array of food products, including bread, cured meats,
jams and jellies, and other sauces and spreads. The Vitamin C properties of ascorbic acid make it
an excellent ingredient for vitamin supplementation. Simply adding ascorbic acid to food
es the Vitamin C content. Since naturally occurring Vitamin C is easily destroyed, many
foods are fortified with ascorbic acid to replenish the Vitamin C content. Ascorbic acid is often
added to fruit juices, dried fruit, cereal, and other snack foods for this purpose.
Chelating or sequestering agents protect food products from many enzymatic reactions that
promote spoilage during processing and storage. These agents bind to many of the minerals that
calcium and magnesium) and are required as cofactors for the activity
Disodium ethylenediaminetetraacetic acid (EDTA):
is one of the most commonly used preservatives for a number of packaged foods; it has
and associated allergy and reaction cases. Though use in a lot of food
products and cosmetics it is known to cause skin allergies and reactions, besides aggravated
asthma problems and kidney damage.
is the acid form of edetate, a chelating agent with anti-hypercalcemic and
Edetic acid binds calcium and heavy metal ions, forming soluble stable
complexes which are readily excreted by the kidneys. This results in a decrease in
levels. This agent is also used as an anticoagulant for blood specimens and is
applied as a treatment of lead poisoning.
Ascorbic acid is used primarily as an antioxidant, which can
Slowing the oxidation preserves color (cut apples and avocados brown when they come into
preserves the freshness. The low pH of ascorbic acid can help
prevent microbial growth, thereby preventing spoilage and preserving freshness. For these
a vast array of food products, including bread, cured meats,
Vitamin C properties of ascorbic acid make it
an excellent ingredient for vitamin supplementation. Simply adding ascorbic acid to food
es the Vitamin C content. Since naturally occurring Vitamin C is easily destroyed, many
foods are fortified with ascorbic acid to replenish the Vitamin C content. Ascorbic acid is often
Chelating or sequestering agents protect food products from many enzymatic reactions that
promote spoilage during processing and storage. These agents bind to many of the minerals that
calcium and magnesium) and are required as cofactors for the activity
is one of the most commonly used preservatives for a number of packaged foods; it has
and associated allergy and reaction cases. Though use in a lot of food
products and cosmetics it is known to cause skin allergies and reactions, besides aggravated
hypercalcemic and
and heavy metal ions, forming soluble stable
results in a decrease in
levels. This agent is also used as an anticoagulant for blood specimens and is
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Structure:
Molecular Formula: C10H12O8CaN2Na2·2H2O
Foods That Contain EDTA: Processed fruits and vegetables, such as canned mushrooms, may
contain EDTA. The EDTA binds with any traces of metal left in food from processing or storage
in metal containers, keeping the metal from causing artificial colors to break down or food to
spoil or discolor more quickly. Fruits and vegetables that sometimes contain EDTA include
frozen potatoes, dried bananas and canned beans.
Canned shellfish, including shrimp and clams, often contains EDTA to prevent discoloration.
EDTA also helps keep condensed milk from thickening, maintains the color of dried egg powder
and maintains the flavor of milk. It acts as an antioxidant to keep packaged meat from turning
brown due to contact with oxygen.
 Food Flavorings
Artificial flavoring agents are used for enhancing food flavors. Salad dressings and a lot of other
packaged foods use artificial food flavor enhancers. Flavorings are intense preparations which
are added to foods in order to impart taste and/or smell. These food flavors are used in small
amounts and are not intended to be consumed alone. There are certain natural food flavors which
are derived from herbs, spices and substances having an exclusively sweet, sour or salt taste.
These natural food flavors are not included in the definition of flavorings for regulatory
purposes.
a) Monosodium Glutamate (MSG)
Monosodium glutamate, or MSG, is a flavor-enhancing food additive used in Asian cooking. It's
also commonly found in fast foods and commercially packaged food products like chips. MSG is
derived from an amino acid called glutamic acid, which occurs naturally in foods such as
mushrooms, aged parmesan cheese and fermented soybean products like soy sauce. Glutamic acid
belongs to a broad category of compounds called glutamates, which are the source of a flavor
called umami.
Structure:
Chemical formula: C5H8NaNO4· H2O
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MSG in food: MSG is present in many of the items on the menu at fast-food restaurants,
particularly in chicken dishes. MSG is also added to many commercially packaged food products
including:
 Flavored chips and crackers
 Canned soups
 Instant noodles
 Seasoning salt
 Traditional chemical food preservatives
Those are very common and highly used in our daily life. Sugar, Salt & vinegar are the kind of
preservatives which show some effect on microbial growth.
a) Sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in
food. There are various types of sugar derived from different sources. The "table sugar" or
"granulated sugar" most customarily used as food is sucrose, a disaccharide of glucose and
fructose. Sugar is used in prepared foods (e.g., cookies and cakes) and it is added to some foods
and beverages (e.g., coffee and tea).
Chemistry: Sucrose (C12H22O11) is a non reducing disaccharide composed
of glucose and fructose linked via their anomeric carbons. It is obtained commercially from
sugarcane, sugar beet (beta vulgaris), and other plants and used extensively as a food and a
sweetener.
Preserving compatibility of sugar: Sugar preserving action is determined by the ration between
the total sugar quantity in the finished product and the total sugar concentration in the liquid
phase. The concentrations of 60% in the finished product assure food preservation.
The food preserved with sugar, the water activity cannot reduced below 0.845; this value is
sufficient for bacteria and neosmophile yeast inhibition, other technique should be employed to
prevent mould growth.
b) Salt
Sodium chloride is a ubiquitous sodium salt that is commonly used to season food. On the other
hand, Sodium chloride is a metal halide composed of sodium and chloride with sodium and
chloride with replacement compatibilities. When depleted in the body, sodium must be replaced
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in order to maintain intracellular osmolarity, nerve conduction, muscle contraction and normal
renal function.
Effect of Salt on Food: Salt is used in brines or is directly applied to the food. Their effect is to
increase osmotic pressure at a level which will prevent microorganism development. The cell
growth of the micro organisms is inhibited or the organism itself may be completely destroyed.
Salt also cause dehydration by drawing out and tying up water from the tissue of the food. Salt
added to food also ionizes, yielding the chlorine ion, which is harmful to micro organisms and
interferes with the action of proteolytic enzymes. The more salt used the greater the protection
afforded by the food.
Labels & E-numbers
To regulate the additives, and inform consumers, each additive is assigned a specific number,
termed as "E-number", which is used in Europe for all approved additives. This numbering
scheme has now been adopted and extended by the Codex Alimentarius Commission to
internationally identify all additives, regardless of whether they are approved for use.
E numbers are all prefixed by "E", but countries outside Europe use only the number, whether
the additive is approved in Europe or not. For example, acetic acid is written as E260 on
products sold in Europe, but it is simply known as additive 260 in some countries. Additive 103,
alkanet, is not approved for use in Europe so it does not have an E-number, although it is
approved for use in Australia and New Zealand.
 E 100–199 Colors:
100–109 yellows; 110–119 orange; 120–129 reds; 130–139 blues & violets; 140–149 greens;
150–159 browns & blacks;160–199 gold and others.
 E 200–299 Preservatives:
200–209 sorbates; 210–219 benzoates; 220–229 sulphites; 230–239 phenols and formates
(methanoates); 240– 259 nitrates; 260–269 acetates (ethanoates); 270–279 lactates; 280–289
propionates (propanoates); 290–299 others.
 E 300–399 Antioxidants and acidity regulators:
300–305 ascorbates (vitamin C); 306–309 Tocopherol (vitamin E); 310–319 gallates and
erythorbates; 320–329 lactates; 330–339 citrates and tartrates; 340–349 phosphates; 350–359
malates and adipates; 360–369 succinates and fumarates; 370–399 others.
 E 400–499 Thickeners, stabilizers and emulsifiers:
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400–409 alginates; 410–419 natural gums; 420–429 other natural agents; 430–439
polyoxyethene compounds; 440–449 natural emulsifiers; 450–459 phosphates; 460–469
cellulose compounds; 470–489 fatty acids and compounds; 490–499 others.
 E 500–599 pH regulators and anti-caking agents:
500–509 mineral acids and bases; 510–519 chlorides and sulphates; 520–529 sulphates and
hydroxides; 530–549 alkali metal compounds; 550–559 silicates; 570–579 stearates and
gluconates; 580–599 others.
 E 600–699 Flavour enhancer’s 620–629 glutamates; 630–639 inosinates; 640–649 others.
 E 700-799 Antibiotics
 E 900-999 Miscellaneous 900–909 waxes; 910–919 synthetic glazes; 920–929
improving agents; 930–949 packaging gases; 950–969 sweeteners; 990–999 foaming agents.
 E 1100–1599 Additional chemicals New chemicals that do not fall into standard
classification schemes.
Conclusion: The increasing demand for ready to eat fresh food products has led to challenges
for food distributors regarding the safety and quality of their foods. Artificial preservatives meet
some of these challenges by preserving freshness for longer periods of time, but these
preservatives can cause negative side effects as well. For example Sodium nitrite is a
preservative used in lunch meats, hams, sausages, hot dogs, and bacon to prevent botulism. It
serves the important function of controlling the bacteria that cause botulism, but
sodium nitrite can react with proteins, or during cooking at high heats, to form carcinogenic
Nnitrosamines.
References:
1. Msagati, Titus A. M. (2012). The Chemistry of Food Additives and Preservatives.
2. Code of Federal Regulations. 1997. Title 21. Food and drugs. Parts 100–199. Office of the
Federal Register, National Archives, and Records Administration, Washington, D.C
3. Commission of the European Communities. Food Sciences and Techniques. Reports of the
Scientific Committee on Food: Presentation of an application for assessment of a food
additive prior to its authorization. 1992 (ISBN 92-826- 0135-8).
4. Evaluation of certain food additives and contaminants (Fiftyfifth report of the Joint
FAO/WHO Expert Committee on Food Additives). WHO Technical Report Series No. 901,
2001
5. Shaw, Ian C. (2012). Food Safety: The Science of Keeping Food Safe.
6. https://www.doctorshealthpress.com/food-and-nutrition-articles/
7. https://www.livestrong.com/article/
8. https://pubchem.ncbi.nlm.nih.gov/compound/

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Preservatives

  • 1. 1 FOOD PRESERVATIVES THOSE ARE COMMONLY USED IN FOOD & BEVERAGE INDUSTRY PREPARED BY: SHARJIL MAHMOOD MS Fellow in Food Chemistry & Chemical Assurance Chittagong Veterinary & Animal Sciences University E-MAIL: smah.sm67@gmail.com
  • 2. 2 INTRODUCTION A food preservative is a natural or synthetic chemical that is added to foods or pharmaceuticals to retard spoilage, whether from microbial growth, or undesirable chemical changes. Some methods of food preservation involve the use of salt, sugar or vinegar, which are sometimes considered to be foods rather than additives. Some people believe preservatives are harmful. Food preservatives have been around since centuries ago, as in pickled onions, salted meat and fish, sweetened fruit and spiced foods. As people move away from the countryside and demand for food increased many people rely on processed items as part of their daily sustenance. Foods preservatives help maintain the freshness and shelf life of such food products because without them, they would spoil quickly due to exposure to air, moisture, bacteria, or mould. Either natural or synthetic substances may be added to avoid or delay these problems. Food preservatives, spices, and flavoring agents have been added to foods for thousands of years. These compounds which are added to foods are termed as food additives. Chemical food preservatives are applied to foods as direct additives during processing, or develop by themselves during processes such as fermentation. Food additives can be defined as the Substance or mixture of substance, other than a basic foodstuff which is present in food as result of any aspect of production, processing, storage or packaging. This definition does not include any chemicals that are contaminants pesticides, color additives or new animal drugs. HISTORY OF PRESERVATIVES Preservatives have been used since prehistoric times. Smoked meat for example has phenols and other chemicals that retard spoilage. The preservation of foods has evolved greatly over the centuries, and has been instrumental in increasing food security. The use of preservatives other than traditional oils, salts, etc. in food began in the late 19th century, but was not widespread until the 20th century. IMPORTANCE OF PRESERVATIVES  Maintain consistency and texture: Preservatives sustain smoothness or prevent the food from separating, caking, or clumping. Preservatives slow product spoilage caused by mold, air, bacteria, fungi or yeast. In addition to maintaining the quality of the food, they help control contamination that can cause food borne illness, including life-threatening botulism.  Improve or retain nutritional properties: During preparation process of food some vitamins and minerals are being subjected to destruction. Fortification adds a nutrient that wasn't there before and may be lacking in many people's diets.
  • 3. 3  Delay spoilage: Preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other microorganisms, as well as retarding the oxidation of fats which cause rancidity.  Enhance flavors, textures, and color: Spices, natural and artificial flavors and sweeteners are added to enhance the taste of food. Food colors maintain or improve appearance. Emulsifiers, stabilizers and thickeners give foods the texture and consistency consumers expect. Leavening agents allow baked goods to rise during baking. Some preservatives help control the acidity and alkalinity of foods, while other ingredients help maintain the taste and appeal of foods with reduced fat content. TYPES OF PRESERVATIVES 1. Natural or Class One Food Preservatives In the category of natural food preservatives comes the salt, sugar, alcohol, vinegar etc. These are the traditional preservatives in food that are also used at home while making pickles, jams and juices etc. Also the freezing, boiling, smoking, salting are considered to be the natural ways of preserving food. Coffee powder and soup are dehydrated and freeze-dried for preservation. In this section the citrus food preservatives like citrus acid and ascorbic acid work on enzymes and disrupt their metabolism leading to the preservation. Sugar and salt are the earliest natural food preservatives that very efficiently drop the growth of bacteria in food. To preserve meat and fish, salt is still used as a natural food preservative. Natural preservatives can be classified into:  Plants with natural antimicrobial activities Onion (Allium cepa, L.): Good source of bioactive compounds, such as sulphur containing Compounds and flavonoids. Antimicrobial activity of onion is due to thiosulfinates and other volatile organic compounds and shown inhibition against gram positive and gram negative bacteria. Onion anti yeast, anti-fungal activity is due to presence of organosulfur-containing compounds which inhibit the growth of yeast and fungi. Cardamom (E.Cardamomum): Essential oil is derived from different plant parts of cardamom such as flowers, leaves, stem, barks etc. Extraction methods are supercritical fluid extraction, solvent extraction, hydrodistillation, steam distillation. It contains bioactive components like 1-8 cineole, terpinyl acetate, phenolics, and limonene etc. possesses antimicrobial activities and inhibits the growth of bacteria, virus, fungi, and molds. On the contrary, Essential oils have antioxidants phenolics and flavonoids which is used as natural antioxidants.
  • 4. 4  Antimicrobials from animals Lactoperoxidase: Basically Lactoperoxidase Glycoprotein with high isoelectric point and one Fe group which occurs in milk, saliva and tears of many mammals.Basic Function of lactoperoxidase is to oxidize thiocynate and some halides to generate products and affects the cytoplasmic membrane that kill or inhibit growth of microorganisms. Furthermore its exert bacteriostatic effect on Listeria, Staphylococcus and in the addition of LP to starter culture for yogurt production inhibited the acid production and new yogurt produced with extended shelf life Used in oral care products toothpaste and Preservative in ground beef products. Chitosan: Natural biopolymer obtained from the exoskeletons of crustaceans (crabs and shrimp) and arthropods used as active material for its antifungal activity and antibacterial activity. Liu et al. studied the efficacy of chitosan against E. coli and concluded that low molecular weight chitosan is effective for controlling growth. The strong antibacterial activity of chitosan was also observed against S. aureus. Chitosan coating was formed by dipping the products in a chitosan–lactic acid/Na-lactate solution and pH adjusted. Several bacteria and yeast were exposed to chitosan concentrations varying from 40 to 750 mg/l. Gram-negative bacteria seemed to be very sensitive for the applied chitosan (MIC< 0.006% (w/v)) The antimicrobial effect of chitosan were observed on strawberries during 12 days.  Antimicrobials from micro organism Nisin: Only natural antimicrobial peptide approved by the FDA to use as a food preservative obtained from the culturing of L. lactis on natural substrates. Nisin is soluble in water and 100 & 300 IU/g decrease growth of L.monocytogens, S.aureus functions by interacting with the phospholipids in the cytoplasmic membrane of bacteria, thus disrupting membrane function and preventing outgrowth of spores. Nisin is highly active against many of the Gram-positive bacteria which can be completely degraded in alimentary tract so safe to use. Beside this, nisin is used as a food preservative in a number of thermal processed foods, particularly in dairy products, canned foods, plant protein foods and cured meat products and marine products. Natamycin: Which is also known as Pimaricin, produced by a pure culture of Streptomyces natalensis bacteria through fermentation process. Target ergosterol in the cell wall, a building block of yeasts and molds which is responsible for intracellular nutrient transport. Natamycin is very effective at very low levels and is approved in different applications with different level in the world.
  • 5. 5 2. Chemical or class two preservatives: Chemical food preservatives have also been used for quite some time now. They seem to be the best and the most effective for a longer shelf life and are generally food proof for the preservation purpose. These food preservatives are the chemical substances that:  Stop or delay the growth of bacteria and spoilage  Keep foods from becoming rancid or developing black spots  Suppress the reaction when food comes in contact with oxygen,  Heat, and some metals prevent the loss of some essential amino-acids and some vitamins  Enhance the food flavors and colors These artificial preservatives can be added to the food or sprayed on the food. Chemical Preservatives can be depicted as follows:  Antimicrobial agents They inhibit the activity of or kill the bacteria, molds, insects and other microorganisms. Antimicrobial agents those are commonly used in foods are- a) Benzoates: This group of chemical food preservative has been banned in Russia because of its role in triggering allergies, asthma and skin rashes. It is also considered to cause brain damage. This food preservative is used in fruit juices, tea and coffee. In case of sodium benzoates, which is a common type of food preservative and is the sodium salt of benzoic acid. Food manufacturers make sodium benzoate by synthesizing the compounds, sodium hydroxide and benzoic acid, together. In addition to its use as a food preservative, sodium benzoate has other roles in food production as well. There are some side effects associated with excess sodium benzoate consumption in foods, so talk with your doctor about it to make sure you are not ingesting harmful doses of preservatives. Structure: Molecular formula: C7H5O2Na
  • 6. 6 Mechanism: Sodium benzoate preserves food by having anti-fungal properties, protecting foods from invasion by fungi that cause food to spoil and potentially make you sick. Sodium benzoate works by entering the individual cells in the food and balancing its pH level, increasing the overall acidity of the food. By lowering the intracellular pH of certain foods, sodium benzoate creates an environment in which fungi cannot grow and spread. According to the International Program on Chemical Safety, sodium benzoate is heavily used by the soft drink industry due to the demand of high-fructose corn syrup in carbonated drinks. Sodium benzoate increases the acidity of soft drinks, which also increases the intensity of flavor you get from the high-fructose corn syrup. On the back of a soda can, you can find sodium benzoate in the ingredients list as E211, which is the number assigned to it as a food additive. On the other hand, Sodium benzoate is primarily added to acidic foods to enhance their flavor. It can be found in foods such as pickles, sauces, jams and fruit juices. Foods that contain vinegar, such as salad dressings, typically contain very high levels of sodium benzoate. Benzene, a precursor to sodium benzoate, can be found in very small amounts naturally in some fruits, vegetables, meats, dairy products and even drinking water. Health effect: taking sodium benzoate and sodium phenylacetate may result in more severe side effects, including severe bruising, blood in the stools or urine, vomiting blood, difficulty breathing or changes in breathing patterns, drowsiness or unconsciousness. Additional rare side effects include muscle cramps, tremors, rash, restlessness and a feeling of tightness in the chest. 1. Sorbates: such as Sodium sorbate, Potassium sorbate. Potassium sorbate originates from the potassium salt of sorbic acid, which is naturally found in many plants, and prevents the growth of pathogens. According to the Center for Science in Public Interest, the additive is safe to consume. Structure: Molecular Formula: C6H7O2K Mechanism: It’s also known as wine stabilizer", potassium sorbate produces sorbic acid when added to wine. It serves two purposes. When active fermentation has ceased and the wine is racked for the final time after clearing, potassium sorbate renders any surviving yeast incapable
  • 7. 7 of multiplying. Yeast living at that moment can continue fermenting any residual sugar into CO2 and alcohol, but when they die, no new yeast will be present to cause future fermentation. When a wine is sweetened before bottling, potassium sorbate is used to prevent refermentation when used in conjunction with potassium metabisulfite. It is primarily used with sweet wines, sparkling wines, and some hard ciders, but may be added to table wines, which exhibit difficulty in maintaining clarity after fining. Health effect: Long term dietary intake of potassium sorbate can cause nutritional deficiencies, those results in the body does not absorb nutrients, vitamin and minerals properly. Digestive problems can often lead to nutritional deficiencies. 2. Nitrites: such as Sodium nitrite, Commonly used as preservative for ham, bacon, sausages and bologna, it gets converted into nitrous acid when consumed and is suspected of inciting stomach cancer. Germany and Norway have banned the use of this harmful food preservative after declaring it a toxin. Structure: Molecular formula: NaNO2 Mechanism: Sodium nitrite is well known for its role in inhibiting the growth of Clostridium botulinum spores in refrigerated meats. The mechanism for this activity results from the inhibition of iron-sulfur clusters essential to energy metabolism of Clostridium botulinum. However, sodium nitrite has had varying degrees of effectiveness for controlling growth of other spoilage or disease causing microorganisms. Even though the inhibitory mechanisms for sodium nitrite are not well known, its effectiveness depends on several factors including residual nitrite level, pH and salt concentration, reductants present and iron content. Furthermore, the type of bacteria also affects sodium nitrites effectiveness. It is generally agreed upon that sodium nitrite is not considered effective for controlling negative enteric pathogens such as Salmonella and Escherichia coli.  Antioxidants Antioxidants are beneficial in preventing rancidity in fats and foods containing fats. Fats exposed to light, moisture, heat or heavy metal ions become activated and oxidize (reach with available oxygen) to peroxides. Antioxidants are chemical food preservatives that act as free radical scavengers. The most used antioxidants are Butylated Hydroxy Anisole (BHA), Butylated Hydroxy Toluence (BHT), Propyl Gallate, Natural/Synthetic Tocopherols (Vitamin E) Ascorbic Acid (vitamin C) and Lecithin.
  • 8. 8 a) Butylated Hydroxy Anisole (BHA) The common food preservatives for fruits, dried fruits, canned olives and cornstarch, wine vinegar, and wine have side effects in form of headaches, joint pain, heart palpitations, allergies, and cancer. stable even at high temperatures compared to other claimed to be natural. This is one of the biggest reasons why food industry experts suggest using Butylated Hydroxyanisole & Butylated hydroxytoluene Structure: BHA- Molecular Formula: C11 H16 O How do they preserve food: BHA and BHT are antioxidants. Oxygen reacts p BHA or BHT rather than oxidizing to being oxidizable, BHA and BHT are fat salts. In addition to preserving foods, BHA and BHT are also used to preserve fats and oils in cosmetics and pharmaceuticals. Effects on health: BHA and BHT effects. The research leads to conflicting conclusions. The o metabolites of BHA and BHT may contribute to carcinogenicity or tumorigenicity b) Ascorbic Acid: Ascorbic acid is a chemical compound that is commonly found in an antioxidant food additive. Ascorbic acid is a vitamer of Vitamin C, which means it is a compound that provides the same vitamin activity as Vitamin C. Often compounds that produce the same activity of one vitamin and they are often called by that vitamin's name. Ascorbic acid is found in nature in many fruits and vegetables (especially citrus fruits and peppers) and is also produced by the kid produce ascorbic acid and must obtain it from the diet, or else they will develop a deficiency and, in more severe cases, scurvy. Industrially, ascorbic acid is produced through a multistep process involving bacteria that reduce glucose and produce ascorbic acid as a byproduct. Ascorbic acid can be used in a variety of forms, including appear on ingredient lists under different names, such as sodium ascorbate, calcium ascorbate, potassium ascorbate, ascorbyl palmitate, or ascorbyl stearate. Anisole (BHA) & Butylated Hydroxytoluene (BHT): he common food preservatives for fruits, dried fruits, canned olives and peppers, corn syrup, cornstarch, wine vinegar, and wine have side effects in form of headaches, joint pain, heart palpitations, allergies, and cancer. The largest advantage of BHA & BHT is that, it remains stable even at high temperatures compared to other preservatives and additives, which are merely claimed to be natural. This is one of the biggest reasons why food industry experts suggest using Butylated hydroxytoluene. BHT- O2 C15H24O2 BHA and BHT are antioxidants. Oxygen reacts preferentially with oxidizing fats or oils, thereby protecting them from spoilage.In addition to being oxidizable, BHA and BHT are fat-soluble. Both molecules are incompatible with ferric salts. In addition to preserving foods, BHA and BHT are also used to preserve fats and oils in BHA and BHT are excellent preservatives may also be implicated in health The research leads to conflicting conclusions. The oxidative characteristics and/or metabolites of BHA and BHT may contribute to carcinogenicity or tumorigenicity Ascorbic acid is a chemical compound that is commonly found in nature and can be used as Ascorbic acid is a vitamer of Vitamin C, which means it is a compound that provides the same vitamin activity as Vitamin C. Often compounds that produce the same activity of one vitamin and they are often called by that Ascorbic acid is found in nature in many fruits and vegetables (especially citrus fruits and peppers) and is also produced by the kidney of some animals. Humans are not able to produce ascorbic acid and must obtain it from the diet, or else they will develop a deficiency and, in more severe cases, scurvy. Industrially, ascorbic acid is produced through a multistep process eria that reduce glucose and produce ascorbic acid as a byproduct. Ascorbic acid can be used in a variety of forms, including salts and esters. In these forms, it will redient lists under different names, such as sodium ascorbate, calcium ascorbate, potassium ascorbate, ascorbyl palmitate, or ascorbyl stearate. : peppers, corn syrup, cornstarch, wine vinegar, and wine have side effects in form of headaches, joint pain, heart is that, it remains preservatives and additives, which are merely claimed to be natural. This is one of the biggest reasons why food industry experts suggest using referentially with fats or oils, thereby protecting them from spoilage.In addition molecules are incompatible with ferric salts. In addition to preserving foods, BHA and BHT are also used to preserve fats and oils in ay also be implicated in health xidative characteristics and/or metabolites of BHA and BHT may contribute to carcinogenicity or tumorigenicity. nature and can be used as Ascorbic acid is a vitamer of Vitamin C, which means it is a compound that provides the same vitamin activity as Vitamin C. Often there is several compounds that produce the same activity of one vitamin and they are often called by that Ascorbic acid is found in nature in many fruits and vegetables (especially citrus ney of some animals. Humans are not able to produce ascorbic acid and must obtain it from the diet, or else they will develop a deficiency and, in more severe cases, scurvy. Industrially, ascorbic acid is produced through a multistep process eria that reduce glucose and produce ascorbic acid as a byproduct. and esters. In these forms, it will redient lists under different names, such as sodium ascorbate, calcium ascorbate,
  • 9. 9 Structure: Molecular Formula: C6H8O6 Ascorbic Acid Used in Food: provide multiple benefits to food products Slowing the oxidation preserves color (cut apples and avocados brown when they come into contact with oxygen) and it preserves the freshness. The low pH of ascorbic acid can help prevent microbial growth, thereby preventing spoilage and preserving freshness. For these reasons, ascorbic acid is a popular natural ingredient preservative. It can be used as a preservative in jams and jellies, and other sauces and an excellent ingredient for vitamin supplementation. Simply adding ascorbic acid to food increases the Vitamin C content. Since naturally occurring Vitamin C is easily destroyed, many foods are fortified with ascorbic acid to replenish the Vitamin C content. Ascorbic acid is often added to fruit juices, dried fruit, cereal, and other snack foods for  Chelating Agent Chelating or sequestering agents protect food products from many enzymatic reactions that promote spoilage during processing and storage. These agents bind to many of the minerals that are present in foods (e.g. calcium and magnesium) and are required as cofactors for the activity of certain enzymes. a) Disodium ethylenediaminetetraacetic acid EDTA is one of the most commonly used preservatives for a number of packaged foods; it has multiple negative impacts and associated allergy and reaction cases. Though use in a lot of food products and cosmetics it is known to cause skin allergies and reactions, besides aggravated asthma problems and kidney damage. Edetic Acid is the acid form of anticoagulant properties. Edetic acid complexes which are readily excreted by the kidneys. This serum calcium levels. This agent is also used as an anticoagulant for blood specimens and is applied as a treatment of lead poisoning Ascorbic acid is used primarily as an antioxidant, food products. Slowing the oxidation preserves color (cut apples and avocados brown when they come into preserves the freshness. The low pH of ascorbic acid can help prevent microbial growth, thereby preventing spoilage and preserving freshness. For these reasons, ascorbic acid is a popular natural ingredient preservative. It can be used as a preservative in a vast array of food products, including bread, cured meats, jams and jellies, and other sauces and spreads. The Vitamin C properties of ascorbic acid make it an excellent ingredient for vitamin supplementation. Simply adding ascorbic acid to food es the Vitamin C content. Since naturally occurring Vitamin C is easily destroyed, many foods are fortified with ascorbic acid to replenish the Vitamin C content. Ascorbic acid is often added to fruit juices, dried fruit, cereal, and other snack foods for this purpose. Chelating or sequestering agents protect food products from many enzymatic reactions that promote spoilage during processing and storage. These agents bind to many of the minerals that calcium and magnesium) and are required as cofactors for the activity Disodium ethylenediaminetetraacetic acid (EDTA): is one of the most commonly used preservatives for a number of packaged foods; it has and associated allergy and reaction cases. Though use in a lot of food products and cosmetics it is known to cause skin allergies and reactions, besides aggravated asthma problems and kidney damage. is the acid form of edetate, a chelating agent with anti-hypercalcemic and Edetic acid binds calcium and heavy metal ions, forming soluble stable complexes which are readily excreted by the kidneys. This results in a decrease in levels. This agent is also used as an anticoagulant for blood specimens and is applied as a treatment of lead poisoning. Ascorbic acid is used primarily as an antioxidant, which can Slowing the oxidation preserves color (cut apples and avocados brown when they come into preserves the freshness. The low pH of ascorbic acid can help prevent microbial growth, thereby preventing spoilage and preserving freshness. For these a vast array of food products, including bread, cured meats, Vitamin C properties of ascorbic acid make it an excellent ingredient for vitamin supplementation. Simply adding ascorbic acid to food es the Vitamin C content. Since naturally occurring Vitamin C is easily destroyed, many foods are fortified with ascorbic acid to replenish the Vitamin C content. Ascorbic acid is often Chelating or sequestering agents protect food products from many enzymatic reactions that promote spoilage during processing and storage. These agents bind to many of the minerals that calcium and magnesium) and are required as cofactors for the activity is one of the most commonly used preservatives for a number of packaged foods; it has and associated allergy and reaction cases. Though use in a lot of food products and cosmetics it is known to cause skin allergies and reactions, besides aggravated hypercalcemic and and heavy metal ions, forming soluble stable results in a decrease in levels. This agent is also used as an anticoagulant for blood specimens and is
  • 10. 10 Structure: Molecular Formula: C10H12O8CaN2Na2·2H2O Foods That Contain EDTA: Processed fruits and vegetables, such as canned mushrooms, may contain EDTA. The EDTA binds with any traces of metal left in food from processing or storage in metal containers, keeping the metal from causing artificial colors to break down or food to spoil or discolor more quickly. Fruits and vegetables that sometimes contain EDTA include frozen potatoes, dried bananas and canned beans. Canned shellfish, including shrimp and clams, often contains EDTA to prevent discoloration. EDTA also helps keep condensed milk from thickening, maintains the color of dried egg powder and maintains the flavor of milk. It acts as an antioxidant to keep packaged meat from turning brown due to contact with oxygen.  Food Flavorings Artificial flavoring agents are used for enhancing food flavors. Salad dressings and a lot of other packaged foods use artificial food flavor enhancers. Flavorings are intense preparations which are added to foods in order to impart taste and/or smell. These food flavors are used in small amounts and are not intended to be consumed alone. There are certain natural food flavors which are derived from herbs, spices and substances having an exclusively sweet, sour or salt taste. These natural food flavors are not included in the definition of flavorings for regulatory purposes. a) Monosodium Glutamate (MSG) Monosodium glutamate, or MSG, is a flavor-enhancing food additive used in Asian cooking. It's also commonly found in fast foods and commercially packaged food products like chips. MSG is derived from an amino acid called glutamic acid, which occurs naturally in foods such as mushrooms, aged parmesan cheese and fermented soybean products like soy sauce. Glutamic acid belongs to a broad category of compounds called glutamates, which are the source of a flavor called umami. Structure: Chemical formula: C5H8NaNO4· H2O
  • 11. 11 MSG in food: MSG is present in many of the items on the menu at fast-food restaurants, particularly in chicken dishes. MSG is also added to many commercially packaged food products including:  Flavored chips and crackers  Canned soups  Instant noodles  Seasoning salt  Traditional chemical food preservatives Those are very common and highly used in our daily life. Sugar, Salt & vinegar are the kind of preservatives which show some effect on microbial growth. a) Sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. There are various types of sugar derived from different sources. The "table sugar" or "granulated sugar" most customarily used as food is sucrose, a disaccharide of glucose and fructose. Sugar is used in prepared foods (e.g., cookies and cakes) and it is added to some foods and beverages (e.g., coffee and tea). Chemistry: Sucrose (C12H22O11) is a non reducing disaccharide composed of glucose and fructose linked via their anomeric carbons. It is obtained commercially from sugarcane, sugar beet (beta vulgaris), and other plants and used extensively as a food and a sweetener. Preserving compatibility of sugar: Sugar preserving action is determined by the ration between the total sugar quantity in the finished product and the total sugar concentration in the liquid phase. The concentrations of 60% in the finished product assure food preservation. The food preserved with sugar, the water activity cannot reduced below 0.845; this value is sufficient for bacteria and neosmophile yeast inhibition, other technique should be employed to prevent mould growth. b) Salt Sodium chloride is a ubiquitous sodium salt that is commonly used to season food. On the other hand, Sodium chloride is a metal halide composed of sodium and chloride with sodium and chloride with replacement compatibilities. When depleted in the body, sodium must be replaced
  • 12. 12 in order to maintain intracellular osmolarity, nerve conduction, muscle contraction and normal renal function. Effect of Salt on Food: Salt is used in brines or is directly applied to the food. Their effect is to increase osmotic pressure at a level which will prevent microorganism development. The cell growth of the micro organisms is inhibited or the organism itself may be completely destroyed. Salt also cause dehydration by drawing out and tying up water from the tissue of the food. Salt added to food also ionizes, yielding the chlorine ion, which is harmful to micro organisms and interferes with the action of proteolytic enzymes. The more salt used the greater the protection afforded by the food. Labels & E-numbers To regulate the additives, and inform consumers, each additive is assigned a specific number, termed as "E-number", which is used in Europe for all approved additives. This numbering scheme has now been adopted and extended by the Codex Alimentarius Commission to internationally identify all additives, regardless of whether they are approved for use. E numbers are all prefixed by "E", but countries outside Europe use only the number, whether the additive is approved in Europe or not. For example, acetic acid is written as E260 on products sold in Europe, but it is simply known as additive 260 in some countries. Additive 103, alkanet, is not approved for use in Europe so it does not have an E-number, although it is approved for use in Australia and New Zealand.  E 100–199 Colors: 100–109 yellows; 110–119 orange; 120–129 reds; 130–139 blues & violets; 140–149 greens; 150–159 browns & blacks;160–199 gold and others.  E 200–299 Preservatives: 200–209 sorbates; 210–219 benzoates; 220–229 sulphites; 230–239 phenols and formates (methanoates); 240– 259 nitrates; 260–269 acetates (ethanoates); 270–279 lactates; 280–289 propionates (propanoates); 290–299 others.  E 300–399 Antioxidants and acidity regulators: 300–305 ascorbates (vitamin C); 306–309 Tocopherol (vitamin E); 310–319 gallates and erythorbates; 320–329 lactates; 330–339 citrates and tartrates; 340–349 phosphates; 350–359 malates and adipates; 360–369 succinates and fumarates; 370–399 others.  E 400–499 Thickeners, stabilizers and emulsifiers:
  • 13. 13 400–409 alginates; 410–419 natural gums; 420–429 other natural agents; 430–439 polyoxyethene compounds; 440–449 natural emulsifiers; 450–459 phosphates; 460–469 cellulose compounds; 470–489 fatty acids and compounds; 490–499 others.  E 500–599 pH regulators and anti-caking agents: 500–509 mineral acids and bases; 510–519 chlorides and sulphates; 520–529 sulphates and hydroxides; 530–549 alkali metal compounds; 550–559 silicates; 570–579 stearates and gluconates; 580–599 others.  E 600–699 Flavour enhancer’s 620–629 glutamates; 630–639 inosinates; 640–649 others.  E 700-799 Antibiotics  E 900-999 Miscellaneous 900–909 waxes; 910–919 synthetic glazes; 920–929 improving agents; 930–949 packaging gases; 950–969 sweeteners; 990–999 foaming agents.  E 1100–1599 Additional chemicals New chemicals that do not fall into standard classification schemes. Conclusion: The increasing demand for ready to eat fresh food products has led to challenges for food distributors regarding the safety and quality of their foods. Artificial preservatives meet some of these challenges by preserving freshness for longer periods of time, but these preservatives can cause negative side effects as well. For example Sodium nitrite is a preservative used in lunch meats, hams, sausages, hot dogs, and bacon to prevent botulism. It serves the important function of controlling the bacteria that cause botulism, but sodium nitrite can react with proteins, or during cooking at high heats, to form carcinogenic Nnitrosamines. References: 1. Msagati, Titus A. M. (2012). The Chemistry of Food Additives and Preservatives. 2. Code of Federal Regulations. 1997. Title 21. Food and drugs. Parts 100–199. Office of the Federal Register, National Archives, and Records Administration, Washington, D.C 3. Commission of the European Communities. Food Sciences and Techniques. Reports of the Scientific Committee on Food: Presentation of an application for assessment of a food additive prior to its authorization. 1992 (ISBN 92-826- 0135-8). 4. Evaluation of certain food additives and contaminants (Fiftyfifth report of the Joint FAO/WHO Expert Committee on Food Additives). WHO Technical Report Series No. 901, 2001 5. Shaw, Ian C. (2012). Food Safety: The Science of Keeping Food Safe. 6. https://www.doctorshealthpress.com/food-and-nutrition-articles/ 7. https://www.livestrong.com/article/ 8. https://pubchem.ncbi.nlm.nih.gov/compound/