Now the question comes: how can water activity help us in avoiding the microbial growth? Yeast, moulds, bacteria require certain amount of water for their growth and water activity can indicate that minimum amount of free water available for microbial growth. So, when microorganisms get sufficient amount of water they flourish in that environment leading to microbial spoilage and may cause food borne illnesses. Microorganisms require water for transporting nutrients, cellular wastes and maintaining cell shape. ![]() Water has a significant contribution to the growth of microorganisms. When it comes to food safety microbial spoilage is one of the main concerns especially in the case of perishable or high moisture foods. Water activity can determine the safety and stability of a food product with regards to microbial growth, and chemical, biochemical and physical properties. So, determining water activity of a medium helped in controlling the spoilage due to microbial growth. Over the period of time, they realized that free water is more important for the stability of food than total amount of water ( Rahman & Labuza, 2007 ). In 19th century, scientists began to correlate the water content of the food with its tendency to spoil. In scientific terms, it is the ratio of vapour pressure of water in food product to the vapour pressure of pure water at same temperature (Sandulachi, 2012). In simple words water activity is the measurement of the water that is not bound to other food constituents and is available for microbial growth, chemical and biochemical reactions. ![]() However, the shelf stability of a product can be achieved by controlling the water activity of the product. Moisture content includes both free water and bound water and thus indicates total amount of water in the food. When we talk about food safety and preservation, a common term comes across i.e. Whereas the Free water is available for biochemical reactions and microbial growth, bound water is not. ![]() It is usually bound to other food constituents like carbohydrates and proteins. Bound water is not available for biological functions. In food, water is present in two forms i.e. When it comes to food safety and preservation water is the most significant factor. Water is a universal solvent and most important constituent of any food.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |