Nida Firdous - National Institute of Food Science and Technology, University of Agriculture, Faisalabad, Punjab, Pakistan

Purpose: International agencies have advocated that monitoring food security and world food resources are necessary to meet the needs of growing populations and to minimize postharvest losses. This paper focuses on the biochemical and physiological bases of changes that causes post-harvest losses and ways to mitigate them. By controlling these metabolic changes, some degree of preservation is possible. Findings: Postharvest losses are 30-50% in developing countries due to energy crisis and lack of proper handling procedures and refrigeration; in contrast to less than 15% in developed countries. Highly perishable commodities like fruits and vegetables are living entities which are characterized by life evolving activities like respiration, transpiration, ripening and metabolic changes. Various compositional changes, such as chlorophyll degradation, softening, and ascorbic acid losses can result in short shelf life. Total 63 species of vegetables are grown in Pakistan but onions, potatoes, tomatoes, garlic, green chilies, coriander, spinach, pumpkin and okra are mostly grown and consumed. Limitations: In Pakistan due to energy crisis and economic constraints no cold food chains/transport is available as a result of which fresh produce endured post-harvest losses.  There is a need to use production technologies supplemented with postharvest techniques to mitigate postharvest losses.Directions for Future Research: Many new technologically viable preservation techniques like modified atmosphere packaging and controlled atmosphere storage should come into existence due to increased health consciousness, increased purchasing power and an increase in percentage of postharvest losses (25-80% fresh produce) which could be applied with such economic constraints.

Food Security, post-harvest techniques, perishable, Shelf life, tomatoes