(a) Main ways that food can be contaminated; (i) Through the action of microorganisms (bacteria, germs) (ii) Through the introduction of chemical substances (iii) Through the introduction of physical contaminants.
(b) Thickening agents for sauces; (i) Vegetable puree (ii) Egg yolk (iii) Butter (iv) Fruit puree (v) Roux (vi) Flour (vii) Starch (yam, cocoyam, potatoes) (viii)Arrow root (ix) Cream/milk (x) Beurre manie (xi) Rice/ground rice (xii) Achi (xiii) Beans (xiv) Melon ('Egusi'/'agusi')