This document provides an overview of various food additives that are commonly used to control properties in food emulsions such as pH, texture, flavor, and stability. It discusses 10 categories of food additives: 1) pH control using acids and bases, 2) minerals and their effects on stability, 3) chelating agents to prevent oxidation from metals, 4) antioxidants to prevent lipid oxidation, 5) antimicrobials to prevent spoilage, 6) flavors, 7) colorants, 8) weighting agents to control creaming, 9) fat replacers to reduce calories, and 10) references for further information. The additives are selected based on the emulsion properties needed for different food types.

1. 1
Food Additives

2. Content
1. Introduction
2. pH control
3. Minerals
4. Chelating Agents
5. Antioxidants
6. Antimicrobial Agents
7. Flavors
8. Colorants
9. Weighting Agents
10. Fat Replacers
Reference
2

3. 1. Introduction
3
Food Emulsion
Food Addition
o Stability
o Taste
o Texture
o Appearance
 Food additives related to many substances which are incorporated into foods
for any functional purposes.
 Common Food additive: acidulants, preservatives, flavorings, colorings,
vitamins, minerals, and antioxidants.
Polar or
Hydrophilic
Nonpolar or
Lipohilic
Emulsifier

4. 4
Source: https://ediblesciencefaire.wordpress.com/emulsion-poster/

5. 2. pH control
5
 pH plays a very important role in determining the physicochemical,
microbiologic, and organoleptic properties of food emulsions.
 pH range 2.5 (beverage emulsions) to 7.5 (infant formulations).
 Adjusted by adding organic or inorganic acids or bases.
 pH can be lowered by
o acetic, lactic, citric, malic, fuamric, succinic, or phosphoricacids.
o biochemical reactions: bacteria (streptococci lactobacilli) or enzymes (δ-
gluconolactone).
 pH can be increased by phosphate, citrate, carbonate, bicarbonate, oxide, and
hydroxide salts.

6. 2. pH control
6
 pH of an aqueous solution can be stabilized by
using an appropriate buffering system.
 The type of buffering system depends on the pH
of food.
o pH 2.1–4.7 for citric acid–sodium citrate.
o pH 3.6–5.6 for acetic acid–sodium acetate.
o pH 2.0–3.0, 5.5–7.5 and 10–12 for the three
ortho- and pyrophosphate anions. Source:
https://www.slideshare.net/akari
m717/emulsion-stability

7. 3. Minerals
 Minerals are making an important contribution to the physicochemical and sensory
properties of foods.
 Different forms like free ions, complexes, and compounds; depending on their type
and the environmental conditions (pH, ionic strength, temp., solution composition.
 Solubility in the aqueous and oil phases.
 High concentrations of minerals can affect on the aggregation stability of O/W
emulsions containing electrostatically stabilized droplets.
 Low mineral concentrations (<5 mM) can be used.
 Common minerals (good for health): calcium, iron, selenium, and zinc.
 Adverse health effects: overconsumption Na+  hypertension ( blood pressure).
 Fe and Cu ions promote lipid oxidation, called undesirable chemical reactions.
7

8. 8
Ca2+
Attractive gelation
Ca2+ in an emulsion (O/W) containing negatively
charged droplets
Source: https://www.slideshare.net/VivekVardhanReddyErr/vivekthesis

9. 3. Minerals
9
+ Fe3+ 
EDTA EDTA chelating ion
 Add chelating agents to sequester the mineral ions and prevent food from
chemical instability.
 Careful selection and control of the mineral ions present in food emulsions is
therefore important when formulating a successful product.
EDTA molecules wrap around a
Fe3+ to prevent oxidation and
precipitation.
Source:
http://plantphys.info/plant_physiol
ogy/minerals.shtml

10. 4. Chelating agents
 Chelating agents are added to foods to sequester multivalent mineral ions
 Beneficial functions in food emulsions: improving the solubility of mineral ions,
inhibiting lipid oxidation, retarding color or flavor loss, and preventing aggregation
of charged droplets.
 Synthetic chelating agents: ethylene diamine tetra acetate (EDTA), phosphoric acid,
and polyphosphates
 Natural chelating agents, such as citric acid (less effective)
10
+ Cu2+ 

11. 5. Antioxidants
11
 Lipid oxidation: chemical reactions,
causes deterioration in product quality
(off-flavor, loss polyunsaturated
lipids, and toxic reaction).
 Three stages: initiation, propagation,
and termination.
 Termination step: nonradical
compounds – hydrocarbons,
aldehydes, alcohols, volatile ketones
and lipid polymers, some of which are
harmful
file:///D:/Master%20Degree/Food%20colloid%20and%20emu
lsification/38461.pdf

12. 12
 Antioxidants: control of oxidation substrates (oxygen & lipids), control of prooxidants
(reactive oxygen species & prooxidant metals), and inactivation of free radicals
1. Synthetic antioxidants: BHA, BHT, TBHQ, are chain-breaking antioxidants, highly
effective at controlling lipid oxidation “label friendly”
2. Chelation of transition metals, replenishing of hydrogen to primary antioxidants,
oxygen scavenging, and deactivation of reactive species; converse free radical species
to more stable products
 Transition metals (Fe/Cu) in O/W emulsion is a major factor, promote lipid oxidation
5. Antioxidants

13. 5. Antioxidants
13
 Chelates transition metals and removes them by using synthetic and
natural chelating agents
o EDTA, phosphoric acid, polyphosphates, citric acid, other organic
acids, proteins, and polysaccharides
o choice them depends on the specific food type.
 Lipid oxidation can be retarded in O/W emulsions by
o Antioxidants are coating the oil droplets with a thick interfacial
membrane that is (+) charged so it prevents transition metal ions
coming into close contact with the lipids inside the droplets
+
+
+
+
+
+
++
O/W emulsions
Electrostatic repulsion

14. 6. Antimicrobial Agents
14
 Antimicrobial as a chemical preservatives are added to many types of food emulsions
to prevent spoilage during storage and to ensure safety
 The type of antimicrobial agent used depends on the pH and thermal processing of the
product
o Chemical source: acetic acid (pH 3.0–5.0), benzoic acid (pH 2.5–4.0), sorbic acid
(pH 3.0–6.5), propionic acid (pH 2.5–5.0), sulfites (pH 2.5–5.0), and nitrites (pH
4.0–5.5)
o Natural sources: herbs, spices, and plants
o Other methods: pH control, moisture control, thermal processing, nonthermal
processing, chilling, and freezing

15. 15

16. 7. Flavors
16
 Desirable flavor profile
o Incorporating: NaCl, sucrose, D-limonene, citric acid
o Multicomponent: lemon juice, herbs, spices, flavor oils, milk fat.
 Undesirable flavor profile: by ingredients undergo chemical or biochemical reactions
o food production, storage, or preparation; lipid oxidation, browning reactions, or
enzymatic reactions (aldehydes, ketones, alcohols and hydrocarbons  off-flavors)
 Selecting flavors: based on partitioning between the oil, aqueous, interfacial, and
headspace regions, and rate of mass transport to the taste and odor receptors during
consumption (chapter 9)

17. 17
Flavor-related fermentation products

18. 8. Colorants
 The color is mainly determined by absorb light, range from 380-780 nm.
o Carotenoids detected at 430-480 nm
o Chlorophyll detected at 400-500 nm and 600-700 nm
 Natural pigments: fruit, vegetable, plant extracts
 Synthetic pigments (FD&C colorants): FD&C Red No. 40, FD&C Yellow No. 5, and
FD&C Blue No. 1
 Either oil or water soluble, and dispersed in during the production of emulsions
 Colorants prevent: controlling light levels, oxygen content, pH, and storage
temperatures or adding preservatives (scatters light) makes the product look cloudy or
opaque
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19. 9. Weighting Agents
 Weighting agents used in beverage emulsions to increase creaming stability by
reducing the density contrast between the oil droplets and the surrounding aqueous
phase, thereby reducing the driving force for creaming
 Most common: brominated vegetable oil (BVO) =1240–1330 kg/m3, sucrose acetate
isobutyrate (SAIB) =1150 kg/m3, dammar gum =1060 kg/m3, ester gum =1080 kg/ m3
 BVO used in food oils: corn oil, soybean oil, cotton seed oil, or olive oil
19
+ n Br2 
Triacylglycerols BVO
o molecule have the density
of the sugar water
o keep citrus and oil-based
flavorings
o cloudy solution

20. 10. Fat Replacers
20
 Fat replacers is used because of obesity problem, to reduced fat, low-fat, or fat-free
versions of traditional products
 Main purposes: providing identical physical, stability of food emulsions and sensory
properties as fat but low or without calories.
 Fat mimetics: Carbohydrate, and proteins are providing creamy, moisture retention,
smooth texture, bulkiness….
o Carbohydrates (0-4 kcal/g): modified starches, gums
o Proteins (4 kcal/g): only O/W emulsion, denaturation at high temp. (frying), gelatin
of margarine to increase smoothness and creaminess as it melts
o Synthetic compounds: contain triacylglycerol-like structural and functional groups

21. 21

22. Reference
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1. Lindsay, R. C. (1996). Food Additives, in Food Chemistry (3rd ed.). Fennema, O.R., Ed.,
Marcel Dekker, New York, NY, Chap. 12.
2. McClements, D. J. (2005). Food Emulsions Principles, Practices, and Techniques (2nd Ed.).
New York: CRC Series in Contemporary Food Science.
3. Miller, D. D. (1996). Minerals, in Food Chemistry (3rd ed.). Fennema, O.R., Ed., Marcel
Dekker, New York, NY, Chap. 9.
4. Reische, D .W., Lillard, D. A., Eitenmiller, R. R. (1998). Food Lipids: Chemistry, Nutrition
and Biotechnology, Akoh, C.C., Min, D.B., Eds., Marcel Dekker, New York, NY
5. Tan, C. T. (2004). Beverage emulsions, in Food Emulsions (4th ed.). Friberg, S., Larsson, K.,
Sjoblom, J., Eds., Marcel Dekker, New York, NY, Chap. 12.