MICROORGANISMS INVOLVED IN THE DETERIORATION OF PSIDIUM GUAJAVA FRUIT SHELF LIFE AND ITS CONTROL BY LOCAL PRESERVATIVES
DOI:
https://doi.org/10.63075/539qt643Keywords:
Guava, spoilage, preservation, zone of inhibition, antibacterial and antifungal activitiesAbstract
Psidium guajava, the guava tree, is a well-known tropical tree that is widely cultivated for its fruit. Guava has been used in medicine worldwide for a long time. Due to the deterioration of guava losses, its nutritional effects can be preserved by using local preservatives. The purpose of the current study is to determine which bacteria cause Psidium guajava to deteriorate and to assess the effect of local preservatives on microbes. Guava samples were collected from four different market districts of Kohat. Samples were inoculated on nutrient agar and potato dextrose agar media and were incubated for 24 hours at 37 oC and for 7 days at 25 oC, respectively. After incubation, bacterial and fungal isolates were obtained, which were subcultured using the pour plate technique to check the effect of preservatives by using the well diffusion method. Zones of inhibition were measured after 24 hours of incubation. The bacterial isolates identified were Bacillus neizhouensis, Lysinibacillus fusiformis, and Brevibacillus agri, and the fungal isolate was Neoscytalidium dimidiatum. The effect of preservative solutions on bacterial isolates was checked by the well diffusion method. ZOI of vinegar (55, 40, 55, 40 mm), honey 5% (30 mm), sugar (26 mm), and sodium bicarbonate (25, 27, 23 mm) solutions. Neoscytalidium dimidiatum showed no growth with vinegar, slow growth with sodium bicarbonate, and fast growth with sugar, honey, and salt. In this study, bacteria (Lysinibacillus fusiformis, Bacillus altitudinis, Bacillus neizhouensis, and Brevibacillus agri) and Neoscytalidum dimidiatum (fungus) were found in spoiling Psidium guajava at the harvest stage. Vinegar, sodium bicarbonate, sugar, and honey solutions showed strong antimicrobial effects against bacteria and fungi obtained from spoiling guava. These preservative solutions can be used to increase the shelf life of Psidium guajava for domestic and commercial purposes.
