Postharvest Parameters of the “Fuerte” Avocado When Refrigerated in Different Modified Atmospheres

Uso de diferentes embalagens e atmosferas modificadas no armazenamento pós-colheita de muricis in natura

Resumo O murici (Byrsonima crassifolia L. Kunth), pertencente à família Malpighiaceae, também conhecido como murici-do-campo, é um fruto típico do Cerrado. É consumido no Brasil pelas populações locais tanto na forma in natura quanto nas formas processadas, tais como sucos, licores, sorvetes, geleias, iogurte, pães e bolos. A partir dessas possibilidades, este trabalho teve como objetivo verificar se o uso de diferentes embalagens e atmosferas modificadas é eficiente no armazenamento pós-colheita de muricis in natura. Muricis in natura foram armazenados a 12 ± 2 °C e umidade relativa de 60% ± 4% em diferentes embalagens, utilizando-se esquema fatorial triplo 3×2×9, para avaliar periodicamente três embalagens (polipropileno – PP, polietileno de baixa densidade – PEBD e poliamida/polietileno – PA/PE), submetidas a duas modificações de atmosfera (a vácuo e sem vácuo), durante nove dias (0, 2, 4, 6, 8, 10, 12, 14 e 16 dias). Os frutos foram avaliados quanto a luminosidade, teores de sólidos solúveis, acidez titulável, pH e índice de maturação. Os dados foram submetidos à análise de variância (p < 0,05) e, quando significativos, foi realizada análise de regressão. A embalagem PA/PE, aliada ou não ao uso da atmosfera modificada ativa (vácuo), pode ser indicada para o armazenamento refrigerado (12 ± 2 °C) de muricis in natura, por ter proporcionado vida útil de 16 dias.

Effects of 1-Methylcyclopropene and Controlled Atmosphere on Ethylene Synthesis and Quality Attributes of Avocado cvs. Edranol and Fuerte

Avocado production worldwide relies on several varieties, with “Hass” being the most commercialized; however, the available genotypes include a number of green-skin varieties with important roles in several countries. Because many technologies have already been developed in “Hass” avocado, the main objective of this study was to evaluate the effects of controlled atmosphere (CA) storage and 1-methylcyclopropene (1-MCP) application during long-term storage of “Edranol” and “Fuerte” avocados. Fruits of both varieties were harvested at two maturity stages: an early harvest close to 20–23% dry matter (DM) content and another after two months, with 22% and 32% DM content for Edranol and Fuerte, respectively. After harvest, the fruit was stored under the following conditions: (i) regular air storage (RA), (ii) CA with 4% O2and 6% CO2, and (iii) 1-MCP applied at 300 ppm. Avocados were stored at 5°C and 85% relative humidity. Physiological and quality evaluations were performed immediately after 30 and 50 days; afterwards, the avocados were maintained at 20°C (shelf life) until they reached the ready-to-eat stage. Ethylene synthesis was assessed by measuring the transcript accumulation of the ACO and ACS genes. The two varieties showed distinct respiration and ethylene production rates during ripening, and fruit stored under CA or after application of 1-MCP showed lower respiration rates than fruit stored under RA, with the lowest rate in 1-MCP-treated avocados. ACS and ACO transcript levels were also lower under both conditions. CA and 1-MCP were very effective tools for extending storage life mainly by reducing the fruit softening rate and the incidence of pulp disorders in both varieties, and interestingly, these techniques did not severely affect the days to reach the ready-to-eat stage. Therefore, the use of CA and 1-MCP technologies in “Fuerte” and “Edranol” seems to be suitable for maintaining quality through 50 days of storage.

Influence of Bioactive Compounds Incorporated in a Nanoemulsion as Coating on Avocado Fruits (Persea americana) during Postharvest Storage: Antioxidant Activity, Physicochemical Changes and Structural Evaluation

The objective of the present study was to determine the effect of the application of a nanoemulsion made of orange essential oil and Opuntia oligacantha extract on avocado quality during postharvest. The nanoemulsion was applied as a coating in whole fruits, and the following treatments were assessed: concentrated nanoemulsion (CN), 50% nanoemulsion (N50), 25% nanoemulsion (N25) and control (C). Weight loss, firmness, polyphenol oxidase (PPO) activity, total soluble solids, pH, external and internal colour, total phenols, total flavonoids, antioxidant activity by 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), while the structural evaluation of the epicarp was assessed through histological cuts. Significant differences were found (p < 0.05) among the treatments in all the response variables. The best results were with the N50 and N25 treatments for firmness and weight loss, finding that the activity of the PPO was diminished, and a delay in the darkening was observed in the coated fruits. Furthermore, the nanoemulsion treatments maintained the total phenol and total flavonoid contents and potentiated antioxidant activity at 60 days. This histological study showed that the nanoemulsion has a delaying effect on the maturation of the epicarp. The results indicate that using this nanoemulsion as a coating is an effective alternative to improve the postharvest life of avocado.