Abstract The work aimed to evaluate the effects of applying chitosan edible coating with the addition of different concentrations of clove essential oil in minimally processed strawberries. The strawberries were selected and sanitized, had their leaves removed, and were submerged in the coatings. Three treatments were obtained: T1 - control (uncoated strawberries); T2 - 2% chitosan + 1% clove essential oil; T3 - 2% chitosan + 1.5% clove essential oil. After receiving the coatings, the strawberries were placed in PET containers and stored at 5±1°C for 12 days. Physical, chemical and microbiological analysis were performed. T2 and T3 samples were more efficient in reducing mass loss (13.78% and 13.51%) when compared the control sample (24.19%). They were also effective in maintaining texture and color for longer. The treatment T3 was more effective to increasing the shelf life and slowing growth, especially of molds and yeasts. The use of different concentrations of clove oil prolonged the quality of strawberries during refrigerated storage.

Abstract The aim of this study was to evaluate the properties of nanocomposite films of protein isolates from mechanically deboned chicken meat with organoclay (montmorillonite). For the film development, a 23 experimental design was performed with three levels, protein isolate (2, 3.5, 5 g.100 mL-1 of solution), montmorillonite (0.3, 0.5, 0.7 g.100mL-1 of solution) and glycerol (25, 30, 35 g.100 mL-1 CPI). The tensile strength varied between 6.7 and 9.1 MPa, elongation to break from 26-66%, opacity of 13.1 to 35.7 and solubility from 38.5% to 81.8%. Assessing the structural properties, interleaving of the isolate and montmorillonite can be noted. The results obtained in the experimental design indicate that 2.0 g of CPI.100 g-1 of solution, 0.8 g of MMT.100 g-1of solution and 0.2 g of glicerol.100 g-1CPI are the ideal parameters for preparing nanocomposite films.

O objetivo deste trabalho foi avaliar as propriedades de biofilmes nanocompósitos de isolado proteico de corvina (Micropogonias furnieri) com argila organofílica. Inicialmente, foi obtido isolado proteico de corvina (IPC) utilizando-se o processo de mudança de pH. O IPC foi obtido a partir de subprodutos da industrialização de corvina. Para o desenvolvimento dos filmes, foi executado um planejamento experimental de Box e Behnken, com três níveis de IPC (2; 3,5; 5 g.100 g-1 de solução), argila montmorilonita MMT (0,3; 0,5; 0,7 g.100 g-1 de solução) e glicerol (25, 30, 35 g.100 g-1 IPC). Os filmes poliméricos foram desenvolvidos pela técnica de casting. Os valores de resistência à tração variaram entre 7,2 e 10,7 MPa, e os valores de alongamento, de 39,6 a 45,8%. Os valores de permeabilidade ao vapor de água (PVA) variaram entre 3,2 e 5,5 g mm m-2 d-1kPa-1. O IPC apresentou teor médio de proteína de 97,87% (b. s.). Pode-se concluir que os filmes nanocompósitos produzidos a partir de IPC com MMT foram promissores, desde o ponto de vista das propriedades mecânicas, da aparência visual e do fácil manuseio até a baixa permeabilidade ao vapor de água e a baixa solubilidade. Com relação às propriedades mecânicas, as concentrações de IPC e MMT foram os principais fatores que influenciaram o desenvolvimento dos filmes nanocompósitos. Os resultados obtidos no planejamento experimental utilizado indicaram que 3,5 g de IPC.100 g-1 de solução, 0,5 g de MMT.100 g-1 de solução e 30 g de glicerol.100 g-1 IPC seriam os parâmetros ideais para a preparação de filmes nanocompósitos por casting.

The objective of this study was to evaluate the properties of nanocomposite biofilms based on Whitemouth croaker (Micropogonias furnieri) protein isolate with organophilic clays. Initially the croaker protein isolate (CPI) was obtained using the pH shifting process from by-products of croaker industrialization. A Box and Behnken experimental design was used to develop the films, with three levels of CPI (2, 3.5 and 5 g.100 g-1 solution), montmorilonite MMT clay (0.3, 0.5 and 0.7 g.100 g-1 solution) and glycerol (25, 30 and 35 g.100g-1 CPI). The polymeric films were produced by the "casting" technique. The tensile strength values ranged from 7.2 to 10.7 MPa and the elongation values from 39.6 to 45.8%. The water vapor permeability (WVP) values ranged from 3.2 to 5.5 (g.mm.m-2.d-1.kPa-1) and the CPI had an average protein content of 97.87% protein (d. b.). It was concluded that the nanocomposite films produced from CPI with MMT were promising from the standpoint of their mechanical properties, visual appearance and easy handling, as well as for their low water vapor permeability and low water solubility. With respect to their mechanical properties, the concentrations of CPI and MMT were the main factors influencing the development of the nanocomposite films. The results obtained from the experimental design indicated that 3.5 g of CPI.100 g-1 solution, 0.5 g of MMT.100 g-1 solution and 30 g of glycerol.100 g-1 CPI would be the ideal parameters for the development of nanocomposite films by "casting".