Effect of Some Natural Oils on Prolonging the Storage Period of Winter Guava Fruits (Psidium guajava L.)

Abstract

Essential oils have antioxidant and antimicrobial properties, so it is considered one of the most suitable methods to maintain overall fruit quality, reduce decay and extend the shelf life of fruit during storage. Therefore, two experiments using fruits harvested from 14-year-old guava trees in a private farm located in Al-Busayli village, Rashied, Bohaira governorate, Egypt, during the 2021and 2022 seasons. The primary objective was to evaluate the influence of essential oils on the overall quality and extension of the shelf-life of winter guava fruit. The fruits were subjected to various treatments, including dipping in the following solutions (at 1000 ppm) for 5 minutes: control (distilled water), clove oil, eucalyptus oil, mustard oil, and jojoba oil. Subsequently, the coated fruits with essential oils were preserved in cold room with a temperature of 7±1°C and a relative humidity of 90 -95 % for a duration of 24 days. The obtained data revealed that immersing in essential oils of winter guava fruits at concentration of 1000 ppm significantly reduced loss in weight of fruit, rot and respiration rate in addition its also improved fruit firmness. SSC%, acidity, SSC/acid ratio and ascorbic acid content compared to control treatment during cold storage. Moreover, the results show a significant reduction in loss of weight, decay, and respiration rate of guava fruits when Eucalyptus and clove oils were utilized. Furthermore, the applications of Eucalyptus and clove oils demonstrated effectiveness in keeping firmness, acidity, vitamin C content, SSC%, and SSC/acid ratio in guava fruits during the storage. In conclusion, Eucalyptus oil and cloves oil proved to be highly effective in reduce weight loss, decay, and respiration rates while concurrently maintaining the overall quality of winter guava fruits under cold storage conditions for a duration of 24 days, in comparison to the other treatments.