Chitosan based coating on post-harvest quality of strawberry cv. Aromas.

O morango ?? um fruto altamente perec??vel, apresentando per??odo de conserva????o p??s-colheita relativamente curto em virtude de altera????es fisiol??gicas e incid??ncia de podrid??o f??ngica, o que limita sua comercializa????o in natura. As coberturas comest??ves ?? base de quitosana tem-se mostrado como alternativas no controle das altera????es p??s-colheita respons??veis pela deteriora????o do morango. Este trabalho foi dividido em dois ensaios experimentais. No primeiro artigo, avaliou-se a aplica????o de coberturas comest??veis ?? base de quitosana contendo c??lcio e ??cidos graxos para promover a manuten????o da qualidade p??s-colheita de morangos cv. Aromas durante o armazenamento refrigerado. Tr??s coberturas foram estudadas: quitosana + cloreto de c??lcio (QC); quitosana + cloreto de c??lcio + ??cido ol??ico (QCAO); quitosana + cloreto de c??lcio + ??cido este??rico (QCAE). Ap??s aplica????o das coberturas, os frutos foram mantidos por 10 dias sob condi????es de 0+2??C e 75+5%UR. A firmeza, o pH, a acidez titul??vel, o conte??do de s??lidos sol??veis e a cor n??o apresentaram varia????o significativa ao final do armazenamento, n??o sendo verificada diferen??a entre os tratamentos quando comparados ao controle. A cobertura apresentou efeito significativo na redu????o da podrid??o f??ngica dos frutos cobertos com QC, verificando-se uma redu????o de 83%. Os frutos que receberam as coberturas QC ou QCAE apresentaram mesma aceita????o que os frutos controle. No segundo artigo, avaliou-se o efeito de coberturas comest??veis ?? base de quitosana, combinada ou n??o com c??lcio e ??cido asc??rbico, na manuten????o da qualidade p??s-colheita de morangos durante o armazenamento refrigerado (0??C) e sob temperatura ambiente (25??C). Quatro coberturas foram estudadas: quitosana (Q); quitosana + cloreto de c??lcio (QC); quitosana + ??cido asc??rbico (QA) e quitosana + cloreto de c??lcio + ??cido asc??rbico (QCA). Ap??s aplica????o das coberturas, os frutos foram mantidos por 15 dias, a 0+2??C e 75+5%UR (refrigerado) e ?? 25??C + 2??C (ambiente) durante 7 dias. Nas amostras refrigeradas, a utiliza????o de coberturas promoveu manuten????o da Lacidez titul??vel, redu????o de perda de firmeza e do desenvolvimento f??ngico, sendo este completamente inibido nos frutos cobertos com QA e QC at?? o d??cimo segundo dia de armazenamento. O pH, o conte??do de s??lidos sol??veis, a cor (L*, C* e h*), o conte??do de antocianinas e o de compostos fen??licos n??o sofreram influ??ncia da aplica????o da cobertura. Nos frutos armazenados ?? temperatura ambiente, foi verificado o efeito da cobertura na manuten????o da firmeza, e no controle do desenvolvimento f??ngico, n??o sendo observado efeito sobre a perda de massa e demais par??metros estudados. De forma geral, pode-se concluir que a aplica????o p??s-colheita de coberturas ?? base de quitosana em morangos preserva sua qualidade durante o armazenamento. A incorpora????o de ??cido asc??rbico ou cloreto de c??lcio na cobertura possibilita ganho adicional no controle do desenvolvimento f??ngico, obtendo-se maior aceita????o para as coberturas contendo ??cido asc??rbico. O uso dessa cobertura permite estender a vida ??til de morangos armazenados sob refrigera????o e ?? temperatura ambiente, por at?? doze e tr??s dias, respectivamente.Strawberry is a highly perishable fruit, presenting a post-harvest shelf life relatively short due to physiologic changes and incidence of fungal decay, which limitate its fresh commercialization. Chitosan based edible coating are a good alternative on controlling post harvest changes associated do strawberry decay. This work was divided in two experiments. In first article, the application of chitosan edible coatings added of calcium and fat acid to promote preservation of the quality of strawberry cv. Aromas during refrigerated storage. Three coatings were studied: chitosan + calcium chloridre (QC), . chitosan + calcium chloride + oleic acid (QCAO), and chitosan + calcium chloride + stearic acid (QCAE). After coatings were applied, the fruits were stored at + 2??C e 75 ?? 5%HR for 10 days. Firmness, pH, titratable acidity, content of soluble solids and, color weren t affected significantly at the end of storage, and no differences between treatment were observed. Coating affected significantly fungal decay on QC coated fruits when compared to non coated fruits, promoting 83%. Fruits that received QC or QCAE coating obtained same acceptability of control fruits. In the second article, the ability of chitosan edible coating, added of calcium and/or ascorbic acid to maintain strawberry post-harvest quality under refrigerated (0??C) and atmospheric (25??C) storage was evaluated. Four coatings were studied: chitosan (Q); chitosan + calcium chloridre (QC), chitosan + ascorbic acid (QA), and chitosan + calcium chloride + ascorbic acid (QCA). After coatings were applied, the fruits were stored for 15 days at 0 + 2??C e 75 ?? 5%HR (refrigerated) and for 7 days at 25??C + 2??C (atmospheric). Firmness, pH, titratable acidity, content of soluble solids and, color weren t affected significantly at the end of storage, and no differences between treatment were observed. On refrigerated condition, chitosan coatings promoted the maintenance of titrable acidity, reduction of loss of firmness and of fungal decay, which was completely inhibited on the fruits covered with QA and QC until the twelve day. Soluble solids content, pH, color (L*, C*, h*), anthocyanins content and phenolic compounds content weren??t affected by coating. On the strawberry stored under atmospheric temperature, coatings promoted retention of firmness and controlled fungal decay, showing no effects on the other attributes evaluated. In general, post-harvest application of chitosan based edible coatings preserve strawberry quality during storage. Incorporation of ascorbic acid or calcium chloride on coating promotes additional gain on the control of fungal decay, being observed a higher acceptability of coatings containing ascorbic acid. The employ of this coating can extend the shelf life of refrigerated or atmospheric stored strawberry until 12 and 3 days, respectively