which food preservative is preffered for leafy vegetable
Answers
Green leafy vegetables (GLV) are multi-cultural components used ubiquitously in Indian cuisine. They are rich sources of calcium, iron, β-carotene, vitamin C, dietary fiber and many trace minerals. A large number of leaves from different sources such as perennial trees, aquatic plants and annuals are consumed and especially in rural areas. These vegetables are an economic source to ensure the micronutrient intake. GLV are seasonal and also highly perishable due to their high water content. There are heavy losses due to non-availability of sufficient storage, transport and proper processing facilities at the production point (Pande et al. 2000). There is a need to preserve the nature’s storehouse of nutrients through convenient processing techniques. Dehydration seems to be the simplest technology for preserving GLV, especially when they are abundantly available.
Vegetable dehydration is generally done either for preserving the perishable raw commodity against deterioration or to reduce the cost of packaging, handling, storing and transporting. The most serious constraint for shelf-life enhancement is the activity of micro-organisms. Water in food is reduced to a very low level during dehydration, thus achieving better microbiological preservation and retarding many undesirable reactions during storage (Ibarz and Barbosa-Canovas 2000), owing to the reduction in water activity. In the present study dehydration technology is utilized with a different perspective. GLV are rich sources of micronutrients as already discussed earlier and therefore dehydrating them can provide us a concentrated source of micronutrients. Utilizing these micronutrient-rich GLV in a dehydrated form can be a food-based approach to combat the micronutrient deficiencies, which is prevalent in our populations, especially during seasons of their non-availability.
In recent years, exhaustive efforts have been made for an improvement in the nutrient retention of dried products by altering processing methods and/or pretreatment. Blanching is a prerequisite for preservation of green leafy vegetables. It is necessary to prevent the formation of off-flavors, odors and colors. However, it may cause partial destruction of some nutrients like ascorbic acid.