Explain various chemicals associated with food.

During processing of food, several chemicals are added to it to augment its shelf life and to make it more attractive as well. Main types of food additives are listed below:

(i) Food colours

(ii) Flavours and sweeteners

(iii) Antioxidants

(iv) Fat emulsifiers and stabilizing agents

(v) Flour improvers 

(vi) Preservatives

(vii) Nutritional supplements such as vitamins, minerals, etc.

Except for nutritional supplements none of the above food additives has any nutritive value.

In this section we will learn about preservations and sweeteners.

1. Food preservatives

Food items containing moisture get spoiled due to growth of micro-organisms. Growth of micro-organisms in a food material can be inhibited by adding food preservatives. Food preservatives are classified into two groups - Class I and Class II. Class I preservatives comprise sugar, table salt and vegetable oils. The Class II preservatives are chemical preservatives. The chemical substance which is used as food preservative should not be harmful to the human beings. These chemical substances which are supplemented to food materials to avoid their spoilage are called as chemical preservatives.


Benzoic acid or its sodium salt, sodium benzoate is usually utilized for the protection of food materials. For the preservation of fruits, fruit juices, squashes and jams sodium benzoate is used as preservative because it is soluble in water and hence easily mixes with the food product. 0.06% to 0.1% concentration of sodium benzoate is sufficient for the preservation of fruit juices and squashes. Sodium benzoate is metabolized by conversion to hippuric acid, C6H5CONHCH2COOH which is finally excreted in the urine.

Potassium metabisulphite or sodium metasulphite is used for the preservation of colourless food materials such as fruit juices, squashes, apples, lichies and raw mango chutney. These are not used for preserving coloured food materials because sulphur oxide produced from these chemicals is a bleaching agent. These preservatives on reaction with acid of the juice liberate sulphur dioxide which is very effective in killing the harmful micro-organisms present in the food and thus prevents it from getting spoiled.

2. Artificial sweetening agents

Sugar or sucrose is the natural sweetening agent. However, excess consumption of sugar leads to many diseases such as obesity, diabetes, coronary heart disease. Many artificial sweetening agents have been isolated which are much sweeter than sugar. These artificial sweetening agents are non-nutritive in nature and are used as substitutes for sugar in foods and beverages especially soft drinks. Some examples of artificial sweetening agents are saccharin, cyclamates. Saccharin (Ortho-sulphobenzimide) is about 550 times sweeter than cane sugar or sucrose.

The use of cyclamates as sweetening agent has been banned in many countries in view of suspected carcinogenic effects.

Aspartame is one more artificial sweetener. It is methyl ester of the dipeptide aspartyl phenylalanine. It is approximately 100 times sweeter than sucrose.

Aspartame is unstable to heat and therefore, it can be used as a sugar substitute in cold drinks and cold foods only.

Alitame is another artificial sweetening agent. It is approximately 2000 times sweeter than sucrose. It is more stable to heat than aspartame. Since Alitame is a high potency sweetener, it is difficult to control sweetness of food while using this sweetener.

Sucralose is a trichloroderivative of sucrose. It is approximately 600 times sweeter than sucrose. It is steady at cooking temperature.  

   Related Questions in Chemistry

  • Q : Atmospheric pressure Give me answer of

    Give me answer of this question. The atmospheric pressure is sum of the: (a) Pressure of the biomolecules (b) Vapour pressure of atmospheric constituents (c) Vapour pressure of chemicals and vapour pressure of volatile (d) Pressure created on to atmospheric molecules

  • Q : Some basic concepts of chemistry an

    an atom of an element is 10.1 times heavier than the mass of a carbon atom.What is its mass in amu?

  • Q : Concentration factor affected by

    Can someone please help me in getting through this problem. Which of the given concentration factor is affected by the change in temperature: (1) Molarity (2) Molality (3) Mole fraction (4) Weight fraction

  • Q : Crystals of covalent compounds Crystals

    Crystals of the covalent compounds always contain:(i) Atoms as their structural units  (ii) Molecules as structural units  (iii) Ions held altogether by electrostatic forces (iv) High melting pointsAnswer: (i)

  • Q : Molar concentration of Iron chloride

    Provide solution of this question. A certain aqueous solution of FeCl3 (formula mass =162) has a density of 1.1g/ml and contains 20.0% Fecl. Molar concentration of this solution is: (a) .028 (b) 0.163 (c) 1.27 (d) 1.47

  • Q : Quantum Mechanical Operators The

    The quantum mechanical methods, illustrated previously by the Schrödinger equation, are extended by the use of operators. Or, w

  • Q : Influence of temperature Can someone

    Can someone please help me in getting through this problem. With increase of temperature, which of the following changes: (i) Molality (ii) Weight fraction of solute (iii) Fraction of solute present in water (iv) Mole fraction.

  • Q : Number of moles present in water

    Provide solution of this question. How many moles of water are present in 180 of water: (a)1 mole (b)18 mole (c)10 mole (d)100 mole

  • Q : Explain solid in liquid solutions. The

    The French chemist Francois Marie Raoult (1886) carried out a series of experiments to study the vapour pressure of a number of binary solutions. On the basis of the results of the experiments, he proposed a generalization called Raoult's law which states that, <

  • Q : Solubility product On passing H 2 S gas

    On passing H2S gas through a particular solution of Cu+ and Zn+2 ions, first CuS is precipitated because : (a)Solubility product of CuS is equal to the ionic product of ZnS (b) Solubility product of CuS is equal to the solubility product

©TutorsGlobe All rights reserved 2022-2023.