Qualidade e conservação pós-colheita de mamão e umbu sob recobrimentos a base de amido associados à solventes eutéticos profundos naturais

Abstract

Tropical fruits are perishable, requiring efficient postharvest technologies, such as refrigerated storage and modified atmosphere, to maintain quality and increase postharvest life. In this sense, the use of biodegradable coatings using renewable starch sources and non-polluting additives is characterized as an innovative clean technology, with a high impact on adding value and applicable to various fruits. In refrigerated storage, attention must be paid to the minimum safety temperature, avoiding the incidence of physiological disorders, such as cold damage or chilling injury. In this context, an efficient coating, in addition to reducing metabolic rates, should minimize the deleterious effects of this physiological disorder. Thus, starch-based formulated biodegradable coatings associated with natural deep eutectic solvents (NADES) are characterized as clean, sustainable and innovative alternatives for fruit storage. The objective of this work was to evaluate the use of these technologies in the quality and postharvest conservation of papaya and umbu, which was structured in two chapters. The experimental designs were completely randomized, in three replications. Chapter I - Quality and sensory acceptance of 'Golden' papaya under starch coatings containing NADES of ascorbic acid. Papayas were immersed for one minute in the following coatings: cassava starch 2% + NADES 0.75% (2%) and cassava starch 3% + DES 0.75% (3%), followed by air drying, and the control (C), fruits without coating. As main results, papayas coated with 3% starch associated with NADES had reduced mass loss, maintained firmness and ascorbic acid levels, delayed color evolution, indicating a delay in ripening. In addition, all sensory attributes were superior in fruits of this coating, which presented an additional shelf life of at least 6 days compared to the control, based on the purchase intention. Chapter II - Reduction of the chilling injury incidence and postharvest conservation of umbu fruit stored under starch-based coatings associated with NADES. The samples were immersed for 1 minute in the following coatings: 2.5% cassava starch + 0.75% glycerol (FM + gly); cassava starch 2.5% + DES 0.75% (FM + DES); 2.5% yam starch + 0.75% glycerol (FI + gly); yam starch 2.5% + DES 0.75% (FI + DES), followed by air drying, and the control (C), uncoated fruits. The main results were: umbus coated with 2.5% yam starch associated with 0.75% NADES showed reduced mass loss, delayed color evolution, indicating a delay in ripening. Additionally, umbus kept under this coating showed lower rates of physiological damage caused by the chilling, presenting an additional 6 days in the useful life compared to the control, based on the purchase intention. Thus, the use of biodegradable coatings based on starch and NADES in the conservation of post-harvest quality in papaya and umbu is a viable alternative that adds postharvest life to these fruits.