Project entitled 'Development of Automated fumigation chamber for treatment of grapes with SO2 and CO2 and standardization of treatment protocol for export of grapes to New Zealand & Australia

Abstract

The export of grapes from India to the Australia and New Zealand is limited due to strict phytosanitary requirements of these countries. Drosophila suzukii has been considered as an invasion insect in these countries. Therefore these countries demand for fumigation of grapes with CO2 and SO2 at specified concentration for certain period besides the other pack-house protocols and export standards. Fumigation of any food material at large scale with such hazardous gases demands a leak-proof electronically operated fumigation chamber in present scenario. In view of the challenge to establish a sophisticated fumigation system, the APEDA funded a project to ICAR-CIPHET to establish a fumigation chamber and develop process protocols for treatment of grapes. The project was focused to develop and establish an electronically controlled fumigation chamber for treatment of grapes in the grapes producing region and develop protocol for fumigation treatments. The fumigation chamber was designed and then constructed at M/s Sahyadri Farmers Producer Company Limited, Survey No. 314/1 & 314/2, A/P Mohadi, Nashik – 422206, which is a leading company in grapes export business. The chamber has capacity for treatment of one pallet (1500 kg) grapes at a time. The walls and roof of the fumigation chamber are made from PUF panels and joints are leak-proof. The chamber has two sections, one for treatment and the other for placing the cylinders and release system. The fumigation operation is controlled from outside using electronic control panel. The gas injection and evacuation systems are electronically operated and the levels can be varied according to the requirement. Heaters of 2 kW are fitted inside the chamber to maintain the treatment temperature above 16oC. All the operations of the fumigation system are controlled by a BMCS (Building management and control system) program specifically prepared for this fumigation system, which is touch screen operated. The details of construction material is given and some guidelines for fabrication of higher capacity chambers is also included in the report. Pressurized helium leak testing of fumigation chamber was done and found leak-proof and safe for fumigation operation. An operation manual along with safety measures was prepared. The operation protocol was developed. Temperature inside the chamber can be maintained above ambient. The CO2 and SO2 gas concentrations can be maintained between 600-60000±100 ppm and 10-10000±2 ppm, respectively for 1-90 min. The pack house unit operations protocol was also prepared. The fumigation of grapes (packed into punnets and place in CFB boxes) with 6% CO2 for 30 min followed by fumigation with 1% SO2 for 30 min ensured 100% mortality of the adult insects. Fumigation followed by immediate precooling and cold storage for 6-12 days ensured 100% mortality of insects and maggots and safe for export. This fumigation chamber can be constructed in higher capacities also with technical guidance. All the facilities, tools, materials, equipment, sensors, software and trained man-power are available in India. This chamber may also be used for fumigation treatment of other fruits, vegetables, nuts, etc. as per the time and concentration of gases required for the 100% mortality of target pests. However, the protocol for such treatments should be developed and effect of the gases on the quality of the products must be studied to ensure food safety.