Postharvest heat treatments to inhibit Penicillium digitatum growth and maintain quality of Mandarin (Citrus reticulata blanco)

Abstract

Use of fungicides is a common practice as a postharvest treatment to control fruit decay. Nowadays, environment friendly technologies, such as heat treatments, are viable replacements. This study evaluated the effects of postharvest heat treatments (traditional and microwave-assisted) on mandarins intentionally inoculated with Penicillium digitatum. For the studied heat treatments, the target temperature was 50 C, which was held for 2.5 min. After heating, mandarins were cooled and stored at 25 C for 13 days. MW treatments effectively prevented mold growth during storage, while HW only delayed it. Control mandarins (without treatment) showed the highest significant weight loss. Neither thermal treatment nor storage affected fruit juice pH (p > 0.05). Treated mandarins had a significantly lower vitamin C content than control fruits throughout storage, and all mandarins lost firmness by the 13 th day (p < 0.05). Control and MW-treated mandarins had lower citric acid content; however, they retained color, total soluble solids (TSS) and had a higher maturity index. While HW mandarins did not have changes in citric acid content, they had higher TSS, and lower maturity index. MW-assisted treatments were effective at inactivating molds and helped retain some nutritional and physical-chemical characteristics of mandarins. However, juice of MW-treated mandarins was not preferred by judges in the sensory tests, the juice was rated lower than that obtained from the other treatment. Postharvest heat treatments may constitute a helpful application to control mandarin' fungal decay.

Combined Effects of Hot Water and Eucalyptus Leaf Extract on the Storability of Cyprus Local Mandarin

“…Findings of current work showed that the hot water treatment is effective for the prevention of the postharvest weight loss and retention of the fruit quality. Results of present study are in agreement with the ndings of Queb-Gonzalez et al [23] who reported that the postharvest heat treatments prevent the weight loss at mandarin fruits. Hot water treatment was also recommended by several other studies for different citrus species [24,26].…”

“…Previous studies reported that the use of edible coatings [10][11][12] propolis [13], chitosan [14], plants extract or essential oils [15][16][17][18][19] calcium salts [20,21] provides successful control of postharvest fruit decay and improves the storability of fruits. Apart from this, postharvest heat treatment has also reported to provide effective control of postharvest decay and prevent quality loss in storage rooms [22][23][24][25][26]. Previous studies show that both bio-materials and hot water treatment are effective in improving the postharvest storage quality of fruits, but the combination of these studies is very limited.…”

Combined effects of hot water and Eucalyptus leaf extract on the storability of Cyprus local mandarin

“…Previous studies reported that the use of edible coatings [10][11][12] propolis [13], chitosan [14], plants extract or essential oils [15][16][17][18][19] calcium salts [20,21] provides successful control of postharvest fruit decay and improves the storability of fruits. Apart from this, postharvest heat treatment has also reported to provide effective control of postharvest decay and prevent quality loss in storage rooms [22][23][24][25][26]. Previous studies show that both bio-materials and hot water treatment are effective in improving the postharvest storage quality of fruits, but the combination of these studies is very limited.…”

Robotic Heat Treatments for Mango and Prickly Pear Increase Shelf Life and Reduce Pathogen Infection

“…Thermocouple sensors are being used for monitoring temperature within the fruit. Sensors were added below mesocarp and in the center of the fruit to study fruit changes during hot water treatments [58]. Three thermocouples of type J were As well after keeping the fruits for nine and 15 days at ambient storage, 10 prickly pears were cut nearby the sealed surface and in the middle of the fruit to measure TSS changes.…”

“…Heat treatment caused important changes in Postharvest Technology -Recent Advances, New Perspectives and Applications epicuticular wax altering microcrack structure. Mandarins were immersed in hydrothermal treatments, maintaining the fruit surface temperature at 50°C for 2.5 min [58]. Once the mandarin peel heats up, thermal energy transfers by conduction to subsequent layers toward the center.…”