Efeito do quitosano e ácido acético na conservação de uva de mesa

Abstract

R E S U M OTodos os frutos sofrem perdas de qualidade desde o momento da colheita até ao seu consumo. A utilização de quitosano como revestimento edível tem sido uma alternativa no tratamento pós-colheita de uva de mesa com bons resultados. Tendo em consideração que a preparação de revestimentos à base deste biopolímero é realizada em solução de ácido acético, pretendeu-se avaliar se a aplicação do referido ácido terá alguma influência nas características físico-químicas da uva de mesa durante o período de conservação a 1 °C e HR de 95%. Do presente estudo conclui-se que a modalidade de ácido acético apresentou pior comportamento que a modalidade controlo e que para além disso não se verificaram interferências negativas deste ácido na solução de quitosano. A conservação de uva de mesa foi facilmente conseguida até aos 14 dias de conservação em frio com a utilização do revestimento edível à base de quitosano na concentração de 0,8%. Palavras-chave: pós-colheita, qualidade, vida útil, Vitis vinifera L. A B S T R A C TAll fruits suffer quality loss from the time of harvest to their consumption. The use of chitosan as edible coating has been considered as an alternative postharvest treatment with good results in table grape. Considering that coatings based in this biopolymer are prepared in acetic acid solution, it was intended to assess whether the application of the acetic acid has an influence on the physicochemical characteristics of table grapes during their conservation period at 1º C and 95% RH.From the present study, it is concluded that the acetic acid alone has a worse performance than the control mode. However, no negative interference of the acetic acid was found in the chitosan solution. The postharvest conservation of table grapes may be easily achieved even after 14 days of cold storage with the use of a chitosan-based edible coating at a concentration of 0.8%.

Table Grapes: There Is More to Vitiviniculture than Wine…

“…In recent years, there has been a growing interest in the use of innovative and environmentally friendly technologies, such as edible coatings or films and biodegradable films associated with the application of natural compounds, like essential oils, that will both add value to food products and extend their shelf-life [75][76][77].…”

Coalho cheese with incorporated chitosan and as a coating: effect on the viability of Staphylococcus aureus and sensory acceptance

“…The use of chitosan with antimicrobial efficiency in food products is commonly observed in the form of coatings, with a small number of studies that use it as a direct ingredient in the food matrix (ASSIS; BRITTO, 2014;GOL et al, 2015;ARAÚJO;SHIRAI, 2016;CHEVALIER et al, 2016;RICARDO-RODRIGUES et al, 2017). Barros, D. M. et al The survival curve of S. aureus in coalho cheese with chitosan as a coating (Table 2), showed that treatments T2 (10 mg mL -1 chitosan) and T3 (15 mg mL -1 chitosan) had similar results with logarithmic microbial reductions ranging from 0.69 to 3.00 and 0.92 to 3.04, respectively, in relation to the control, considering all the time intervals evaluated (Table 2).…”