Edible Coating Based on Roselle (Hibiscus sabdariffaL.) Mucilage Applied to Soursop Fruits in Postharvest Storage

Abstract

The soursop fruit (Annona muricata L.) is a crop of significant economic value for Nayarit, which is characterized by having a bittersweet taste, making it attractive to the consumer. However, the soursop has rapid maturation which causes a short shelf life. Several postharvest management techniques have been applied to reduce its metabolic processes, such as refrigeration, use of 1-methylcyclopropene (1-MCP), and controlled and modified atmospheres. In recent years, polysaccharide-based coatings have been applied to fruits. Therefore, the objective of this investigation was to evaluate the physicochemical and biochemical changes, as well as the antioxidant activity of soursop fruits with a mucilage-based coating (2%), stored at 22°C and 15°C with a 90% RH. Weight loss, firmness, color, soluble solids, acidity, pH, phenols, flavonoids, vitamin C, and antioxidant activity were evaluated. The results obtained in the coated fruits stored at 15°C showed lower weight loss (6.4%), lower firmness (29.7 N), higher TSS concentration (10.4°Bx), and lower acidity (0.38%) compared with the uncoated fruits. The total phenolic content decreased in coated fruits stored at 22°C (54.3 mg EGA/100 g FW). The highest antioxidant activity (DPPH method) was recorded in fruits coated and stored at 15°C with an average value of 257.9 mg EAA/100 g FW. Moreover, a high concentration of vitamin C was observed in fruits coated and stored at 15°C and 22°C (20.5 and 17.5 mg EAA/100 g FW), concluding that the coating based on roselle mucilage (2%) in combination with a temperature of 15°C prevents weight loss, decreases titratable acidity, and increases the content of phenols and vitamin C. Furthermore, an increase in the shelf life up to eight days and in the antioxidant activity at the maturity of consumption was observed in the fruits coated with 2% roselle mucilage stored at 15°C.

The influence of mucilages extracted from some vegetable plants residues as an edible coating on maintaining the quality of sweet pepper fruits.

“…The literature reported that the application of edible coatings mucilage enhanced the quality parameters and elongated the shelf life [13] of okra mucilage [14,15]. *Corresponding author e-mail: ahmed.abdallah@agr.cu.edu.eg .…”

Edible coatings with avocado oil on the quality of ‘Tommy Atkins’ mangoes

“…The levels of SS in the coated mango decreased because the coatings decreased the rate of respiration, leading to the slow ripening of the fruit (Wei;Mei;Xie, 2021). The levels of SS increased, despite the action of the coatings, because temperature favored the enzymatic reactions, inducing the hydrolysis of starch to sugars (De los Santos-Santos et al, 2020).…”

Impact of Post-harvest Treatments on The Antioxidant Content of Fruits and Vegetables

“…This was probably due to delayed synthesis and accumulation of β-carotene because of lowering O 2 and increasing CO 2 concentrations. On the other hand, the total phenolics and vitamin C contents were increased in soursop fruits coated with roselle mucilage (2%) and stored at 15°C for eight days (De los Santos-Santos et al, 2020). The role of different coatings on antioxidant capacity is related to their effect on delaying fruit ripening and extending their shelf life.…”