FOOD TECHNOLOGY

Detailed explanation-1: -This means sugar absorbs water in the food resulting in the reduction of water activity (aw). Bacteria need water to grow and multiply, so lowering the water activity in a food product means there is less free water molecules for the bacteria. It creates an environment that limits microbial survival and growth.

Detailed explanation-2: -50% sugar is enough to reduce water’s water activity to below 0.92, the amount necessary to prevent the growth of botulism. 67% sugar is enough to reduce water’s water activity to below 0.85, the amount necessary to prevent the vast majority of bacteria from growing.

Detailed explanation-3: -The water activity of a food is the amount of unbound water available for microbial growth and chemical reactions. Salt’s ability to decrease water activity is thought to be due to the ability of sodium and chloride ions to associate with water molecules (Fennema, 1996; Potter and Hotchkiss, 1995).

Detailed explanation-4: -Sugar as a preservative – by acting as a humectant (maintaining and stabilising the water content in foods) sugar helps to prevent or slow the growth of bacteria, moulds and yeast in food like jam and preserves.