Food Preservatives Overview

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Questions and Answers

Which of the following preservatives works primarily by disrupting cell membrane function in bacteria and some molds?

Acetic acid (correct)

Sorbic acid

Sodium nitrite

Natamycin

What is the maximum limit of Benzoic acid in beverages and fruit juices?

0.1-0.3%

0.01-0.05%

0.05-0.1% (correct)

0.1-0.15%

What role do antioxidants play in food preservation?

Prevent the growth of bacteria and molds

Inhibit the enzymatic reactions in fruits

Prevent oxidative rancidity in fats and oils (correct)

Extend the shelf-life of canned foods

Which type of preservative is primarily used to inhibit the Clostridium botulinum bacteria?

Sodium nitrite Signup and view all the answers

Which of the following foodstuffs utilize Sorbic acid for preservation?

Baked products Signup and view all the answers

What is the purpose of antioxidants in cut fruits and vegetables?

Prevent browning and increase shelf-life Signup and view all the answers

Which antioxidant type is soluble in fat?

Vitamins C and E Signup and view all the answers

What mechanism does Natamycin use to prevent mold growth?

Binds sterol groups in fungal membranes Signup and view all the answers

Which of the following is the maximum limit for sodium aluminium silicate when used as an anti-caking agent?

0.5% Signup and view all the answers

What type of emulsion is represented by mayonnaise?

Oil-in-water Signup and view all the answers

Which anti-caking agent can be used in baking powder?

Calcium silicate Signup and view all the answers

Which component is not typically part of the structure of an emulsifier?

Sugar molecules Signup and view all the answers

What is the primary function of antifoaming agents in food products?

Reduce or prevent foaming Signup and view all the answers

Which stabilizer is commonly used to maintain a homogeneous dispersion of immiscible substances?

Lecithin Signup and view all the answers

What is the maximum limit of carbonates of calcium and magnesium in instant mixes and processed cereal goods?

2% Signup and view all the answers

Which of the following is an example of an antifoaming agent?

Dimethyl polysiloxane Signup and view all the answers

Which of the following substances is NOT classified as a thickener?

Citric acid Signup and view all the answers

What is one of the primary functions of glazing agents in food production?

To provide a shiny appearance Signup and view all the answers

Which of the following sweeteners is considered a high-intensity sweetener?

Acesulfame K Signup and view all the answers

Which substance is commonly used as a stabilizer in food products?

Pectin Signup and view all the answers

What role do acidulants play in food preparation?

To preserve food and enhance flavors Signup and view all the answers

Which of the following is an example of a chelating agent?

Citric acid Signup and view all the answers

What is a common characteristic of bulk sweeteners?

They are used in similar amounts as sugar Signup and view all the answers

Which of the following thickeners is a polysaccharide?

Guar gum Signup and view all the answers

What is the primary purpose of adding colours to foods?

To replace lost colors and improve appearance Signup and view all the answers

Which of the following is a natural colorant?

Caramel coloring (E150) Signup and view all the answers

What distinguishes flavour enhancers from flavouring agents?

Flavour enhancers improve the existing flavours without imparting their own Signup and view all the answers

Which of the following statements is true about Monosodium glutamate (MSG)?

It boosts the flavours of other food components. Signup and view all the answers

What is the main function of anticaking agents in powdered foods?

To ensure free flow and prevent clumping Signup and view all the answers

Which of the following is NOT classified as a flavouring agent?

Natural colourants Signup and view all the answers

Which of the following is an example of a synthetic colorant?

FD&C Green No.3 (E143) Signup and view all the answers

What role do anticaking agents play in complex powdered mixes?

Prevent moisture absorption and clumping Signup and view all the answers

What is the primary function of curing agents in meat products?

To prevent spoilage and improve color Signup and view all the answers

Which of the following is NOT a characteristic of humectants?

They inhibit microbial growth Signup and view all the answers

What compounds are typically used as firming agents in fruit and vegetable processing?

Aluminium sulphates and calcium salts Signup and view all the answers

In the context of food additives, which of the following is a potential disadvantage?

Possible negative health effects Signup and view all the answers

Which of the following correctly describes clarifying agents?

Additives that remove haze or sediments from drinks Signup and view all the answers

What transformation occurs when sodium nitrite is added to meat?

It converts to nitric oxide and forms a heat-stable pigment Signup and view all the answers

Which type of food additive is primarily responsible for enhancing visual appeal?

Curing agents Signup and view all the answers

What role do substances like phenols and tannins play in the context of clarifying agents?

They combine with proteins to form haze in beverages Signup and view all the answers

Study Notes

Preservatives

Prevent growth of microorganisms to reduce food spoilage and food poisoning.
Extend shelf-life of consumer products.
Natural preservatives include vinegar, salt, and sugar; artificial preservatives include sodium benzoate, sodium nitrite/nitrate, and sulphites.
Acetic acid (vinegar) disrupts cell membranes in bacteria, yeasts, and molds; used in mayonnaise and pickles (max 3.6%).
Benzoic acid and benzoate inhibit molds and yeast in beverages and soft drinks (max 0.05-0.1%).
Natamycin binds sterols in fungal membranes; commonly used in cured cheese.
Sorbic acid inhibits molds and yeast in cheese, wine, and baked goods (max 0.3%).
Nitrates and nitrites inhibit bacterial enzymes, primarily Clostridium botulinum, in cured meats.

Antioxidants

Prevent oxidative rancidity in fat and oil-rich foods.
Protect vitamins and amino acids from degradation due to air exposure.
Help maintain appearance of cut fruits, vegetables, and juices by preventing browning.
Two types: water-soluble and fat-soluble antioxidants.

Colors

Used to replace lost colors or enhance food attractiveness.
Simulate perception of naturalness for consumers.
Natural colorants include caramel (E150), annatto (E160b), and turmeric (E100).
Synthetic colorants include FD&C Blue No.1 (E133) and FD&C Red No. 40 (E129).

Flavouring Agents and Enhancers

Flavouring agents impart taste or smell; common examples include spices and herbs.
Flavour enhancers enhance existing flavours without providing flavour themselves; examples include MSG and natural extracts.
Monosodium glutamate (MSG) is a common flavour enhancer, enhancing taste in foods.

Anti-caking Agents

Prevent caking in powdered foods to ensure free flow.
Common anti-caking agents: sodium bicarbonate and calcium silicate (max 5%).
Help maintain the texture of instant mixes, powdered drinks, and table salt.

Antifoaming Agents

Reduce or prevent foaming in foods by lowering surface tension.
Included in foods and cooking oils to control frothing; an example is dimethyl polysiloxane (max 10ppm).

Emulsifiers

Stabilize emulsions of oil and water, facilitating mixing of immiscible liquids.
Two types of emulsions: water-in-oil (e.g., margarine) and oil-in-water (e.g., mayonnaise).
Emulsifiers have both hydrophilic and lipophilic regions.

Stabilizers

Maintain uniform dispersion of immiscible substances in food.
Examples include agar, pectin, and gelatin.

Thickeners

Increase food viscosity without altering other properties.
Types include polysaccharides (e.g., cornstarch), vegetable gums (e.g., xanthan gum), and proteins (e.g., egg whites).

Glazing Agents

Provide a shiny appearance and protective coating on food.
Common examples are stearic acid (E570) and beeswax (E901).

Sweeteners

Improve taste and flavor in foods; include both natural (from sugar cane) and artificial (e.g., aspartame) sweeteners.
High-intensity sweeteners are much sweeter than sugar, while bulk sweeteners have similar sweetness levels to sugar.

Acidulants

Enhance flavors and act as preservatives; include vinegar and citric acid.

Chelating Agents

Scavenge metals that catalyze oxidation; examples are EDTA and citric acid.

Curing Agents

Used in meat preservation to inhibit microorganisms while imparting color and flavor; sodium nitrite is commonly used.

Humectants

Retain moisture to prevent food from drying out; examples include glycerol and sorbitol.

Firming Agents

Keep fruits and vegetables crisp; typically aluminium sulphates and calcium salts.

Clarifying Agents

Remove haze from beverages like beer and fruit juices; examples include bentonite and gelatin.

Advantages of Food Additives

Extend shelf-life and improve transportability of processed foods.
Maintain consistent food quality.
Enhance visual appeal for consumers.

Disadvantages of Food Additives

Potential health risks or adverse effects on consumers.
May lead to reduced food quality perceptions.
Overconsumption can result in health issues.

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Description

Explore the role of preservatives in preventing food spoilage and food poisoning. This quiz covers both natural and artificial preservatives, their mechanisms of action, and examples found in various foodstuffs. Test your knowledge on how these agents extend shelf-life and their applications in food safety.