Effectiveness of Sodium Alginate and Carnauba Wax Nanoemulsions with Lemongrass Essential Oil on the quality of ‘Hass’ Avocado Fruit from early, middle, and late harvest season during prolonged cold storage

Abstract

Avocado (Persea Americana Mill.) has gained popularity as a widely produced and consumed fruit worldwide, raising concerns about its storage and transportation. The avocado, being a climacteric fruit sensitive to chilling injury, faces challenges that affect its shelf life and commercial viability. This research delves into the effectiveness of edible sodium alginate 2 % (weight/weight, w/w) (SA) and carnauba wax 1 % (w/w) (CW) coatings, both independently and in combination with lemongrass essential oil, sodium alginate 2 % (w/w) + lemongrass essential oil 1.25 % (SALG) and carnauba wax 1 % + lemongrass essential oil 1.25 % (w/w) CWLG) as postharvest treatments. Uncoated avocados were used as control (CT). The nanocoating-treatments aim to preserve the quality of 'Hass' avocados harvested during the early, middle, and late season. After treating the fruits, some from each treatment group were kept at 21 ± 1 ºC for 7 days (shelf life). The rest were stored at 5 ºC and 90 % RH for 15, 30, and 45 days before being submitted also to shelf life. In each sampling date, quality parameters measured included: firmness, color (L*, hue), weight loss, gray pulp symptoms, ethylene production and pulp electrolyte leakage. Also, fatty acids (FA), hydrogen peroxide (H2O2), malondialdehyde (MDA), α-farnesene (Farn) and conjugated trienols (Ctrols) were quantified in avocado pulp. Fruit quality analysis showed that all coatings improve quality and reduction of gray pulp development, especially CW and the incorporation of lemongrass in both matrices. Therefore, these edible coatings can be an alternative to improve preservation of avocado fruit quality through cold storage and subsequent shelf-life, which potentially reduce fruit waste.