Development of W-Step Modified Air System CA Storage

Studies on Simple Controlled Atmosphere Storage of Fruits and Vegetables Part IV

Abstract

The simplification and improvement of efficiency and accuracy to control atmosphere were achieved for Modified Air System CA (MASCA) storage, which is hopeful as the economical CA storage system.
In the proposed system (W-Step MASCA), Modified Air with low oxygen content (less than 1%) was flushed to CA storage container in order to succeed rapid pull down of oxygen, and accumulation of carbon dioxide was established subsequently by respiration. For the control of atmosphere within a certain range, oxygen was supplied from air compressor (Step-1) and excess of carbon dioxide was exhausted (Step-2) with modified air which is evolved from generator according to the W-Step program written in Basic and personal computer. The newly developed program eliminated pressure control of air compressor of modified air generator that is time consuming and sometimes resulted in inaccuracy in the former MASCA. W-Step MASCA is energy-saving and supposed to provide an easy way to automatic operation.
The experiments for storage of shiitake-mushroom and peach showed that W-Step MASCA is reliable enough to control atmosphere, and the shelf-life of these fruits and vegetables were prolonged.