Chapter 4 Food additives

Effects &interaction in the food system.

>What causes food to spoil?

+ microbial reactions, enzymatic reaction, chemical reactions, physical and mechanical

>What is food additive? (= Ingredients with a purpose)

+ any safe substance that is intentionally added into the food in small quantities in order to affect the food's quality. There is natural and artificial food additive; natural and artificial.

>GRAS ( Generally Recognised as Safe) is additives that are generally recognised as safe because of their common and safe use.

> E- Number is reference number given to food additives that have passed safety tests and have been approved., (under Europe and starts with E)

> INS stands for International Numbering System for the food additive.

>There are 7 types of food additives under food regulations 1985:

a) Preservative

-any substance that when added to the food, the food is capable of inhibiting, retarding or arresting the process of decomposition, fermentation and acidification of such food. Does not include herb, spice, vinegar and wood smoke. They are added to extend the shelf life of the product.

b) Antimicrobial Agent

-a substance used to prevent the growth of microorganisms and subsequent spoilage or to sterilise polymeric food-contact surfaces. This includes fungistats, mould and rope inhibitors. (example - sodium benzoate in coke, sodium nitrate in meat, sodium dioxide in fruit juice and dried fruits)

c) Colouring substance

-a substance added to food to impart colour to the food and includes colouring preparation.

-Roles of colouring agents in food:

>replace the natural colour that was lost during processing, air, light, moisture and storage.

>correct natural variations in colour/ enhance the colour

> Provide visual appeal to wholesome and nutritious food.

-Differences between natural and synthetic colouring:

-Examples of natural colourings are carotene, anthocyanin and annatto; whereas synthetic is tartrazine.

d) Flavouring substance

-any substance with flavouring properties either formed by chemical synthesis or obtained from materials of plant or animal origin.(amyl acetate-banana, benzaldehyde-almond flavour)

-Natural flavouring is extracted from plants, fruits, herbs and spice, animal, microbial fermentation.

> Roles in food:

-Impart the characteristic of the flavourings (vanillin in vanilla ice cream)

-Augment, complement or modify a flavour ( vanillin modify the flavour of chocolate)

-Mask the original flavour ( anise cover bitter medicinal)

>Disadvantages of Natural Flavouring:

-High cost (source and seasonal)

-Low density (need large amount)

-Flavour profile (have unwanted flavour profile)

-Flavour variation (depend on the variety of food)

e) Flavour enhancer

-any substance that was added capable of enhancing or improving the flavour of that food.

-MSG: Increase overall perception of flavour, make flavour nicer, brighten the flavour.

-Yeast extract: GMO-free, Clean label, Ideal for vegetarian applications, specific savoury taste profiles.

-Application: Cheese spreads, paste, dips and dressing)

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>Rancidity is the development of unpleasant odours and flavours in food resulting from deterioration in the fat or oil portion of food.

>There are 2 types:

-hydrolytic rancidity 

-oxidative rancidity

>Ways to prevent food rancidity.

-store in a cool dark environment

-store in a closed container

-vacuum packaging of fat containing products

-coloured glass or wraps

-store away from metals: copper/iron

-Additives: antioxidant

f) Antioxidant

-any substance that is capable of delaying or retarding the development in the food of rancidity or other deteriorations due to oxidation.

Example: BHA, propyl gallate, tocopherol

g) Food conditioner.

-any substance that is added to food for a technological purpose to obtain the desired food.

-Example: emulsifier, an anti-foaming agent, stabilisers, thickeners, modified starch, gelling agents, acidity regulators, enzymes, solvents, glazing agent, anti-caking agent.

>Ways to modify a food product?

Additives: Thickeners, gelling agent, emulsifier.

> Why are food additives added into food?

-Improve/maintain nutritional value (to avoid degradation of vitamins, essential amino acids and unsaturated fats; to enriched the vitamins and minerals.

-improve and maintain freshness (reduce wastage; prevent microbial spoilage by retarding oxidation)

-improve taste, texture and appearance (aids in food processing and preparation.)

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