Active antifungal packaging is a technological solution for reducing the postharvest losses of fruits and vegetables associated with phytopathogens. Anthracnose (Colletotrichum gloeosporioides) is the principal fungus that causes post-harvest avocado fruit decay. In this study, antifungal sachets filled with oregano oil-starch capsules were prepared, and their active effects were demonstrated on Hass avocado fruits. Oregano oil (31 % of carvacrol) was encapsulated with corn starch by spray drying. Tyvek sachets (4 × 4 cm) filled with 80 (T1) and 160 mg (T2) of oregano oil-starch capsules (99.35 ± 1.86 mg g − 1) were fabricated. The antifungal effects of the sachets were tested in vitro and in vivo using a humidity chamber (90–95 % relative humidity (RH)) on fruits inoculated with anthracnose. The results showed that T1 and T2 inhibited 75.21 ± 2.81 and 100 % in vitro growth of anthracnose at 25 °C for 12 days. Furthermore, Hass avocado fruits stored in a humidity chamber at 25 °C for 6 days showed that only T2 significantly (p < 0.05) reduced the area of lesion produced by artificial inoculation of Hass avocado fruits with anthracnose. On average, the lesion area in the Hass avocado fruits treated with T2 was 13.94 % smaller than that in the control fruit.
MULTIFILE
Active sachets can be used to manage postharvest losses associated with phytopathogens in fruit and vegetables. Diseases associated with phytopathogens are the principal causes of avocado losses postharvest. This study was performed to develop antifungal active sachet-based oregano oil microencapsulated with starch/agave fructans that allows in vivo and in vitro control of phytopathogens associated with avocado decay. In addition, avocado-sachet interactions were studied. Oregano oil sachets inhibited 100% of the in vitro growth of Colletotrichum gloeosporioides, Colletotrichum acutatum, Diaporthe passiflorae, and Neoscytalidium hyalinum at 30 °C for 12 d The efficacy of the oregano oil sachets was confirmed on avocados inoculated with C. gloeosporioides. Active sachets reduced the injury area of anthracnose infection in avocado without negative effects on the color or firmness of the fruit, compared to untreated control. Treatment also caused significantly higher (p < 0.05) phenylalanine ammonia-lyase, chitinase, β-1,3-glucanase, catalase and peroxidase activities compared to the control fruit. In addition, antifungal sachets significantly enhanced the contents of total flavonoids and phenolic compounds in treated avocados.
