This question was popular among the candidates and their performance was good. In part
          (a)(i) candidates correctly defined food contamination, in part (a)(ii) candidates correctly  
           effects of food contamination on human.  In (b) (i) candidates correctly stated reasons why
           food items are stored, in (b)(ii)  candidates listed food items that can be preserved the
           following methods (i) keeping in silo(ii) adding salt (iii)  sun drying.  In part (c) (i) candidates
           correctly stated advantages and disadvantages of canning as a method of food preservation,
           in (c)(ii) candidates correctly mentioned food  substance which could be canned.

            However, the expected answers were as follows:

            4(a)(i)  FOOD CONTAMINATION
This is a condition in which food contains harmful bacteria/toxin, harmful chemicals
which can cause illness/affect the body negatively
                                                  
      (ii)  EFFECTS OF FOOD CONTAMINATION ON HUMAN

• diseases e.g./named diarrhoea,cholera, dysentery may be contacted
• abdominal pain/stomach upset
• sudden death
• vomiting

                         
 (b)(i)   REASONS WHY FOOD ITEMS ARE STORED

• since food production is seasonal, it is very wise to store food for future use/last long 
• food can also be stored against famine/drought/damage by diseases/pests
• for economic reasons
• to minimize/prevent wastage                                                                                                                                               

• FOOD ITEMS THAT CAN BE PRESERVED BY THE FOLLOWING METHODS
•  KEEPING IN SILO
• maize
• wheat
• soghum   
• millet
• beans
• guinea corn
• rice
• grains

• ADDING    SALT
• meat
• fish
• melon
• locust beans

• SUNDRYING
• meat
• fish
• vegetables
• pepper
• groundnut
• beans
• maize
• cassava
• yam
• unripe plantain
• melon seed

 
  (c)(i)  ADVANTAGES OFCANNING AS A METHOD OF FOOD PRESERVATION      

• it makes seasonal food available at all time
• prevents mass wastage
• it reduces the incidence of immediate spoilage /improve durability

 
            DISADVANTAGES OFCANNING AS A METHOD OFFOOD PRESERVATION             

• very expensive method of food preservation which leads to hike in price of goods
• meat/fish tends to deteriorate after seven/eight years,
• fruit juice tends to corrode if kept for long.
• loss of natural taste mixed with chemical substance as preservative e.g. lacquer
• it can cause food poison

 
     (ii)   FOOD SUBSTANCES WHICH COULD BE CANNED

• fish
• cornbeef/meat
• corn/sweet corn
• tomatoes
• butter
• baked beans
• beverages/tea
• fruits
• milk.