Zero energy cool chambers for extending the shelf-life of green vegetables

Abstract

A zero energy cool chamber (ZECC) consisting of a brick wall cooler and a storage container made of new materials has been developed. The ZECC requires no electric energy. The brick wall cooler made of bricks with a mixture of moistened sand with cement allows low inside temperature and high relative humidity to be maintained based on the principles of a natural evaporative cooling mechanism. Several types of storage containers coated with different antibacterial materials were applied to reduce decay. For example, silver-ion (Ag+)coated storage containers were used to reduce decay and nutrition of vegetables. Washing of vegetables was also applied to the commodities in order to maintain freshness. Generally leafy vegetables, tomatoes and brinjals and cauliflowers had a shelf life of ½, 1, 1and 1 day at room temperature, respectively, as compared to 5, 6, 5 and 6 days in summer season when stored in the ZECC but in stored in winter season generally leafy vegetables, tomatoes and brinjals and cauliflowers had a shelf life of 1, 3, 2 and 2 days at room temperature, respectively, as compared to 10, 12, 11 and 12 days when stored in the ZECC.