Ozone gas exposure to extend shelf-life of tomatoes in hot and humid region
N. G. SHAH, S. S. Zambre, K. V. Venkatesh
Book of Abstracts, 2004 IFT (Institute of Food Technologists) Annual Meeting and Food Expo, 13-16 July 2004, Las Vegas, Nevada, USA. 321 pages.
2004
บทคัดย่อ
Ozone gas exposure to extend shelf-life of tomatoes in hot and humid regionIndia, oflate has been producing large quantities of fresh fruits and vegetables, however, the post harvest losses have been an impediment in keeping average consumption of fresh fruits and vegetables low. Excessive microbial loads is one of the major spoilage agent. Study reported here considered Ozone (O3) exposure for short duration as sanitization agent for tomatoes. O3-in-air having concentrations between 20-50 ppm were used to reduce microbial load and thus extend shelf. Green mature tomatoes were exposed to pre-decided O3- air mixtures in airtight acrylic containers. After the O3 was depleted (half life of O3 in air at 30°C typically 6 hrs) the tomatoes were stored in airtight conditions. Microbial counts were determined before and after treatment. Respiration rates were measured in terms of CO2 generated in mgkg-1 hr-1 to co-relate with shelf-life determined by weight loss and visible decay. Results obtained are :(i) The untreated tomatoes (control) started spoilage from 5th day and the respiration rates started accelerating vis-à-vis treated tomatoes with O3. (ii) Microbial count on tomato surface was reduced by 2 log cycles with 20 ppm of O3 and by 4 log cycles using O3 of 35-50 ppm. The corresponding shelf-life enhancement of 1.1 times, 4.2 times and 5.6 times was observed with O3 of 20, 35 and 50 ppm, respectively. (iii) Weight loss during storage for treated tomatoes was found to be lower as compared to untreated tomato samples during a storage period of 4-16 days. In conclusion, the preliminary experimental work on exposing tomatoes to O3-in-air proposes great potential for enhancing shelf-life of tomatoes stored in hot and humid weather. This work will guide the pilot experiments for ozone treatment of tomatoes and other vegetables.