Investigating the effect of UV-C and ultrasonic treatments on the shelf life of Langra mango fruit

To increase the quality and shelf life of mango fruits (Manjifera indica cv. Langra), a factorial experiment was conducted in the form of a completely randomized design with three replications (18 fruits per replication). Mango fruits in mature green stage were harvested from a commercial mango orchard in Roodan city, Hormozgan province. The first factor was ultraviolet radiation (UV-C) with an intensity of 25 watts at three levels (0, 5 and 10 minutes), the second factor was ultrasonic radiation with a frequency of 35 kHz and a power of 280 watts at three levels (0, 3 and 6 minutes) and the third factor was storage time at five levels (0, 10, 20, 30 and 40 days). After the treatment with the mentioned proportions of UV-C and ultrasonic, the fruits were stored at 10°C and a relative humidity of 80-85%, and the sampling and the measurements were carried out at different times. Based on the results, ultraviolet and ultrasound treatments prevented the increase of L (lightness), a and b  and pH and the decrease of fruit ascorbic acid over time. In ultrasound treatments, the highest amount of ascorbic acid (11.3 mg/100 grams) was found in irradiation for three minutes. In ultraviolet treatments, the decrease of ascorbic acid with time was less than the control, but there was no significant difference between five and ten minutes. Ultrasound treatment for 6 minutes prevented the significant decrease in fruit weight. On the 40th day of storage, the lowest amount of L in fruit flesh (89.44) belonged to ultraviolet treatment for five minutes. Therefore, within 40 days of storage of mango fruit, ultraviolet treatment for five minutes due to maintaining the appearance of the fruit (L ) and ultrasound treatment for three minutes due to maintaining the maximum ascorbic acid of mango fruit are recommended.