Question

The common preservative used in jam and pickles is
A. Sodium benzoate
B. Nitric acid
C. Sodium chloride
D. Copper sulphate

Answer 1

Hint: Preservatives are substances which delay the growth of microbes without necessarily destroying them or prevent degradation of quality during manufacture and distribution.

Complete answer:
The salt form of Benzoic acid i.e. Sodium benzoate is one of the most common chemical food preservatives. Sodium benzoate is a common preservative used in acidified food such as fruit juices, jams, pickles, preserves, fruit cocktails, etc. Yeasts' growth is inhibited by benzoate to a greater extent. Sorbic acid is non-toxic as it gets metabolised. The WHO acceptable standard is a daily intake of 25 mg/kg body weight for sorbic acid. Its salts are tasteless and odourless in foods when used at reasonable levels of < 0.3 % and they show adequate antimicrobial activity. Sorbates are used against mould and yeast growth in foods including raw fruits and vegetables as well as processed foods like fruit juices, pickles, jellies, jams, etc. In jams sugar works as a preservative because it creates osmotic pressure in microbial cells, dehydrates them, effectively shrivels the microbes. In pickles salt bonds with water and dehydrates the pickle. In the absence of free water microbes have no medium to grow. Acetic acid or fruit juices create an unfit acidic environment of pH <4 whereas microbes can thrive only in the pH range of 6.5-7.5.

So, the correct answer is option (A) Sodium benzoate.

Note:
The term “preservatives” refers to a wide variety of compounds that slows down bacterial growth in products, such as foods, medicines, etc. Preservatives can be natural or synthetic. Safety of preservatives in food must be taken care of strictly. The U.S. The Food and Drug Administration (FDA) strictly studies, regulates and monitors the use of preservatives in food products.