What is the primary purpose of adding preservatives to food?

The primary purpose of adding preservatives to food is to prevent or slow down spoilage. This spoilage can be caused by the growth of microorganisms like bacteria, yeasts, and moulds, or by undesirable chemical reactions such as oxidation. By inhibiting these processes, preservatives extend the shelf life of food products, maintain their quality, and most importantly, ensure food safety by preventing the growth of pathogens that could cause foodborne illnesses. Examples include sodium benzoate and sodium metabisulphite.

How do artificial sweeteners like aspartame differ from natural sugars like sucrose?

Artificial sweeteners like aspartame differ significantly from natural sugars like sucrose primarily in their caloric content and chemical structure. Sucrose is a disaccharide providing 4 calories per gram, while aspartame is a dipeptide methyl ester that provides negligible calories because it is used in such tiny amounts due to its intense sweetness (about 100 times sweeter than sucrose). Chemically, sucrose is a carbohydrate, whereas aspartame is a protein derivative. Aspartame also has a limitation of being unstable at high temperatures, unlike sucrose.

What are antioxidants in food, and why are they important?

Antioxidants in food are substances that prevent or delay the oxidation of food components, particularly fats and oils. Oxidation can lead to rancidity, off-flavours, discolouration, and loss of nutritional value. Antioxidants work by scavenging free radicals, which are highly reactive molecules that initiate and propagate oxidative chain reactions. By interrupting these reactions, antioxidants like BHA (Butylated Hydroxyanisole) and BHT (Butylated Hydroxytoluene) help maintain the freshness, flavour, and quality of fatty foods, extending their shelf life.

Is Monosodium Glutamate (MSG) harmful, and what is its function?

Monosodium Glutamate (MSG) is generally recognized as safe (GRAS) by regulatory bodies worldwide when consumed in typical amounts. Its primary function is as a flavour enhancer, providing a unique 'umami' or savoury taste that intensifies the natural flavours of food. While some individuals report sensitivity to MSG, experiencing symptoms like headaches or flushing (often termed 'Chinese Restaurant Syndrome'), scientific evidence has not consistently linked these symptoms to MSG consumption in the general population at typical dietary levels. It is the sodium salt of the amino acid glutamic acid.

Why are edible food colours added to food products?

Edible food colours are added to food products primarily for aesthetic reasons. They serve to make food more visually appealing and attractive to consumers. Additionally, they can be used to compensate for colour loss that might occur during processing or storage, and to ensure uniformity in the appearance of different batches of a product. While they do not add nutritional value or flavour, they play a significant role in consumer perception and acceptance of food items, from candies and beverages to processed meats.

What is the difference between BHA and BHT, and how do they function?

BHA (Butylated Hydroxyanisole) and BHT (Butylated Hydroxytoluene) are both synthetic phenolic antioxidants commonly used in food. Chemically, they are structurally similar but distinct compounds. Their function is identical: to prevent oxidative rancidity in fats and oils. They achieve this by acting as free radical scavengers. They donate a hydrogen atom to lipid free radicals, thereby interrupting the autocatalytic chain reaction of lipid peroxidation. This stabilizes the food product, preventing the formation of off-flavours and odours, and extending its shelf life.

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Drugs and their Classification

Chemicals in Food

Chemistry

NEET UG

Version 1Updated 22 Mar 2026

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Chemicals in food refer to substances intentionally added to food products during processing, packaging, or storage to achieve specific technological or sensory purposes. These substances, often termed food additives, are not typically consumed as food by themselves, nor are they characteristic ingredients of food. Their primary roles include preservation (to prevent spoilage by microorganisms or …

Quick Summary

Chemicals in food, often called food additives, are substances intentionally added to food to serve specific purposes beyond basic nutrition. They fall into several key categories. Food Preservatives like sodium benzoate and sodium metabisulphite prevent spoilage by inhibiting microbial growth or oxidation, thereby extending shelf life and ensuring food safety.

Artificial Sweeteners such as saccharin, aspartame, sucralose, and alitame provide intense sweetness with minimal or no calories, serving as sugar substitutes. Antioxidants, including BHA and BHT, prevent oxidative degradation of fats and oils, which causes rancidity.

Edible Food Colours are used to enhance the visual appeal of food. Lastly, Flavour Enhancers like monosodium glutamate (MSG) intensify the existing taste of food, particularly the umami flavour.

These additives are crucial for modern food processing, distribution, and consumer satisfaction, but their use is strictly regulated for safety.

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Key Concepts

Aspartame: A Dipeptide Sweetener

Aspartame is a widely used artificial sweetener, approximately 100 times sweeter than sucrose. Chemically, it…

BHA and BHT: Phenolic Antioxidants

Butylated Hydroxyanisole (BHA) and Butylated Hydroxytoluene (BHT) are synthetic phenolic compounds that act…

Sodium Benzoate: An Antimicrobial Preservative

Sodium benzoate ( $C_6H_5COONa$ ) is a common food preservative, particularly effective in acidic food products…

Preservatives:

- Sodium Benzoate ( $C_6H_5COONa$ ): Antimicrobial, acidic foods (jams, juices). - Sodium Metabisulphite ( $Na_2S_2O_5$ ): Antimicrobial, antioxidant, jams, squashes. - Propionates: Anti-mould in bread.

Artificial Sweeteners:

- Saccharin: First, 550x sucrose, metallic aftertaste, stable. - Aspartame: Dipeptide, 100x sucrose, heat unstable, PKU concern. - Sucralose: Trichloro derivative of sucrose, 600x sucrose, heat stable. - Alitame: Dipeptide, 2000x sucrose, more stable than aspartame.

Antioxidants:

- BHA (Butylated Hydroxyanisole), BHT (Butylated Hydroxytoluene): Prevent oxidative rancidity in fats/oils.

Flavour Enhancer:

- MSG (Monosodium Glutamate): Umami taste, intensifies flavour.

To remember the key artificial sweeteners and their properties:

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