Effect of 60Co gamma radiation on microbial flora and shelf life of Malus domestica Borkh

摘要

Apples are known worldwide for their pleasant taste. Apples, being perishable and susceptible to microbial spoilage, have a short shelf-life. The current study was carried out to investigate the effect of gamma irradiation treatment for maintaining storage quality and extending the shelf life of apples. Mature Kala kulu apples were collected from local fruit market of Lahore and packed in zip-locked bags. Apples were irradiated with dose range of 1, 1.5 and 2.0 kGy under refrigerated (4oC) conditions. Microbiological evaluations were carried out on 7th, 14th and 21st day of experiment. Sensory evaluations were done after every 7th day and data obtained from irradiated apples was compared with the observations obtained from un-radiated (control) samples. Studies revealed that total bacterial, yeast and mold counts significantly (p≤0.05) decreased in irradiated apples stored at 4°C. Maximum reduction of pathogenic bacteria and fungi at 2 kGy was 74% and 77%, respectively. Sensory evaluation revealed that irradiation treatment of 1kGy signi?cantly maintained the storage quality of the fruit. While with 1.5 and 2 kGy dose treatment, fruit showed reduced firmness early during storage. The dose of 1kGy, proved most effective in enhancing the shelf life of apples by maintaining the fruit quality and hence improving the shelf life. Conclusively, irradiation has positive influence on decreasing microbial flora and increasing shelf life of apples, however appropriate dose must be applied. In the present study our results revealed that there is a great potential for the use of radiation in extending the storage life of apples.