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1. FOOD TECHNOLOGY
Lecture Notes Prepared For 1st Year Students of Nutrition and
Food Science – EAU Garowe
Prepared by; H.Wahab [Lect. Nutrition & Food Science]
habibwahab8@gmail.com @habibwahab3

2. FOOD AND CONSUMER HEALTH
• CONSUMER HEALTH: this is defined in terms of what
people consume in order to be healthy.
• Food: is what we consume to give us nutrients for growth,
sustenance and replacement of worn out tissues.

3. THE RELATIONSHIP BETWEEN FOOD AND
CONSUMER HEALTH
Food with little or no nutrients, incomplete nutrients when
consumed on a regular basis will result into bad health such as
growth retardation, sicknesses, loss of body immunity against
diseases etc
Food with contaminants are harmful to human health
Over processed food will lead to loss of protein and vitamin
Regular consumption of food with only carbohydrate leads to a
condition called kwashiorkor
Lack of enough supply of energy results in a protruded belle, thin
arms and legs or swollen body in a condition called marasmus.

4. TOXICANTS OF FOODS
• A toxicant is any chemical substance that can cause a
damaging effect in a biological system.
• Food toxicant can be divided into three categories, namely
endogenous, naturally occurring and synthetic.

5. ENDOGENOUS TOXICANTS
substances produced by tissue cells in plants and other
biological raw materials.
chemical substances often serve the purpose of protecting plant
tissues from pests, as well as from pathogenic organisms
Transmission to man can be direct consumption of toxic plants or
from animals who have consumed the plant that are then used for
human foods
Examples include flavonoids, goitrogens, coumarins, cyanogenic
compounds, herbal extracts, and mushroom toxins.

6. SYNTHETIC TOXICANTS
They are those that are synthetically produced, which
found their way into our food supply through contamination
of the food processing environment. e.g pesticides,
additives, preservatives.
 Pesticides include insecticides, herbicides, rodenticides,
fungicides, fumigants etc.
Amide herbicides (propanil) which is used extensively to
control harmful weeds in rice crops could cause liver
damage, central nervous system depression and death.

7. NATURALLY OCCURRING TOXICANTS
• They are those produced by organisms that contaminate the food
products.
• Microorganism such as dinoflagellates, fungi, and bacteria can
produce toxicants that upon consumption can cause diseases.
• Some toxin-producing organisms produce toxins in the food
matrix (which can cause intoxication if consumed), while others
produce toxins inside the victim (intoxification).
• some are able to withstand heating temperature used in cooking,
while others are able to tolerate extremes of pH without losing
activity.

8. • Some of these Micro organisms cause very serious diseases
such as typhoid, dysentery, salmonellosis, cholera and food
intoxications.
• They are generally specific depending upon the type of food
and particular conditions of storage.
• e.g moulds (Aspergillus) are commonly associated with
cereal product spoilage, Lactic acid bacteria (Lactobacillus)
spoils raw milk and yeasts (Saccharomyces) spoil fruit juice
when stored under unfavourable conditions.

9. The undesirable changes caused by microorganisms can be
divided into: those that cause food spoilage not usually
associated with human disease and those that cause food
poisoning which could be:
i. food infection,
ii. food intoxication or
iii. food intoxification.

10. FOOD INFECTIONS
• These are caused by disease organisms which are carried to
the host through foods; they multiply in the intestinal tract,
and cause diseases through infection of their tissues.
• Examples of these diseases are cholera, salmonellosis,
shigellosis, ameobiosis.

11. • Cholera is caused by Vibrio comma, transmitted through
drinking water and contaminated food.
• The symptoms are diarrhoea, watery stools and vomiting.
• Salmonellosis is caused by salmonella bacteria transmitted
through foods such as meat, egg and fish. They are easily
killed by normal good cooking, and must be eaten alive in
sufficient number to cause infection.
• Symptoms are abdominal pain, diarrhea, frequent vomiting
and occasional death may occur when untreated.

12. FOOD INTOXICATION
• This is caused by organisms which grow in food and produce chemical
substances in the food which is toxic. Examples are
• Staphylococcal poisoning, caused by Staphylococcus aureus.
• Symptoms are salivation, nausea, vomiting, diarrhea and abdominal
cramps. Sources of contamination are mouth, throat, nose through
coughs and sneezes.
• Botulism which could be very fatal is caused by Clostridium botulinum
transmitted through home canned foods which are not properly
processed.
• Symptoms are vomiting, constipation, difficult of eye movement,
difficulty in speaking. Death could result due to the paralysis of the
muscles responsible for respiration.

13. FOOD INTOXIFICATION
• This is caused by ingestion of bacteria that once inside the
small intestine, begin to produce toxin.
• The organism E. coli is a good example of this type of
pathogen, able to produce toxin after damaging the lining of
the intestine. These toxins are absorbed by the body,
reaching the kidneys where they cause substantial damage
to the convoluted tubules.

14. STEPS TAKEN TO AVOID CONSUMPTION OF
CONTAMINATED FOODS:
 1. Avoid overdose use of pesticides or preservatives such as sodium benzoate.
 2. Samples of food crops or food product should be tested for residual pesticides
or preservatives by appropriate agencies to ensure safety before they are
distributed to the market for consumers.
 3. In preparation of foods, simple unit operations such as peeling/dehulling,
soaking, dewatering, boiling, roasting and drying could get rid of the natural food
toxins and anti nutritional constituents to insignificant levels when properly done.
 4. Properly cooked food before consumption will prevent food poisoning by
microorganisms.
 5. Good hygiene, good handling of food to avoid recontamination after cooking
and proper storage of food before consumption (Good Manufacturing Practices)