Effect of Azadirachta indica and Tamarindus indica leaf extract and evaporative cooling on the quality characteristics and shelf life of sapota (Manilkara zapota)

Abstract

Tropical fruits such as Sapota (Manilkara zapota) are highly perishable. The main reasons for the quality deterioration of these fruits are field heat and microbial attack, which can be reduced by proper cooling techniques and by using antimicrobial agents. The present study was undertaken to extend the shelf life of Sapota using evaporative cooling and antimicrobial coating, namely, neem leaves (Azadirachta indica) and tamarind leaves (Tamarindus indica), at different concentrations (20, 50 and 100%). Coated Sapota fruits were stored for 24 days, whereas uncoated fruits were stored for only 7 days. Both the selected antimicrobial extracts showed antimicrobial activity, and the cooling efficiency of the evaporative cooling chamber was 81-85%. Fruits were cooled to 15-18°C (core temperature), which could enable retention of physio-chemical properties. The results indicated that fruits coated with the highest level (100%) of antimicrobial extract coating (neem leaves and tamarind leaves) and stored under evaporative cooling conditions had the lowest percentage loss in weight (5-7% after 24 days of storage) and good retention of total soluble solids (1-2%), pH (2-3%) and total sugars (3-5%). Thus, coating Sapota fruits with neem leaves and tamarind leaf extracts and storing them under evaporative cooling conditions can be a better way to enhance the shelf life of sapota.