ABSTRACT
Physico-chemical, mechanical, barrier, release profiles and antioxidant properties of composite gelatin based-films incorporated with rutin-loaded oil-in-water nanoemulsion, at various concentrations (5, 10, 15, or 20% (based on the weight of the gelatin powder)) were studied. All the gelatin/rutin-loaded nanoemulsion films displayed higher tensile strength and higher elongation at break than the gelatin control film. The composite films did not show significant differences in thickness, color, brightness and transparency. The structural properties evaluated by FTIR showed that the rutin-loaded nanoemulsion achieved complete miscibility within the gelatin matrix. All the gelatin/nanoemulsion films exhibited compact and homogenous microstructure. In addition, these films showed high antioxidant activities monitored by DPPH radical scavenging and reducing power activities. The Korsmeyer-Peppas model described well the rutin release profile. Rutin release was mainly governed by Fickian diffusion with simultaneous interfering swelling and disintegration phenomena. These results indicate that nanoemulsions-in-gelatin systems can function as potential active packaging systems to enhance shelf life of food products and then to provide a high-quality products (fresh/safe).
Subject(s)
Antioxidants/chemistry , Gelatin/chemistry , Nanostructures/chemistry , Rutin/chemistry , Absorption, Physicochemical , Color , Emulsions , Hydrophobic and Hydrophilic Interactions , Mechanical Phenomena , Permeability , Solubility , SteamABSTRACT
Deep-fat frying is widely used in food industries because of its low cost and high demand, since it produces convenient food of high acceptability. The process is based on the oil-food interaction at high temperatures, which cooks and dehydrates the food, leading to physical and chemical changes, such as starch gelatinization, protein denaturation, flavoring and color production via Maillard reaction. Some food and oil compounds are lost in the frying process, and potentially toxic compounds are developed in the oxidized oil. Although widely studied, many of these compounds have not been fully identified. The purpose of this study was to review literature findings on changes in food caused by the frying process.
Subject(s)
Cooking/methods , Food Analysis , Hot Temperature , Nutritive Value , Oils/chemistry , Oxidation-Reduction , TasteABSTRACT
Moisture equilibrium data of passion fruit pulp powders with maltodextrin and gum arabic were obtained by two different drying methods (spray drying and freeze drying) and determined at 20, 30, 40 and 50º C. Skimmed milk was used to substitute part of these additives in the samples. One formulation using passion fruit pulp/maltodextrin/skimmed milk (PMS) was prepared, and another using passion fruit pulp/gum arabic/skimmed milk (PGS). The behavior of curves was type III, according to Brunauer's classification. GAB models were fitted to experimental equilibrium data. The parameters obtained from GAB models was affected by the presence of additives. The behavior of the sorption isotherms for different temperatures are similar, noting only a small effect of temperature. There were little differences between both drying methods and additives used in relation to equilibrium moisture content. The parameters obtained with the addition of the skimmed milk were considered satisfactory (Xm values ranged from 0,04084 to 0,06488 in dry basis), demonstrating that it is an effective and cheap alternative for regular additives. A progressive increase in the heat of sorption in relation to decreasing moisture content was observed and the heat of sorption values of different samples are all similar, comparing the relative equilibrium moisture content.
Dados de umidade de equilíbrio da polpa de maracujá em pó com maltodextrina e goma arábica obtidas por dois diferentes processos de secagem (spray dryer e liofilizador) foram determinados a 20, 30, 40 e 50° C. Leite desnatado foi utilizado nas amostras em substituição a uma parte desses dois aditivos. Prepararou-se uma formulação, usando polpa de maracujá/maltodextrina/leite desnatado (PMS) e outra com polpa de maracujá/goma arábica/leite desnatado (PGS). Os comportamentos das isotermas obedeceram ao tipo III, de acordo com a classificação de Brunauer e utilizou-se o modelo de GAB para ajuste dos dados de equilíbrio. Os parâmetros obtidos pelo modelo de GAB foram afetados pela presença dos aditivos. O comportamento das isotermas de sorção para as diferentes temperaturas foram similares, notando-se uma pequena diferença em relação ao efeito da temperatura. Observaram-se também pequenas diferenças entre os dois métodos de secagem utilizados e os aditivos usados em relação ao teor de umidade de equilíbrio. Os parâmetros obtidos pela adição do leite desnatado foram considerados satisfatórios (Xm variando de 0,04084 a 0,06488 em base seca) mostrando que o leite desnatado pode ser uma alternativa boa e com menor custo na substituição dos aditivos comumente utilizados nesse tipo de processo. Observou-se uma aumento do calor isostérico de sorção em relação a diminuição do teor de umidade e os valores das diferentes amostras utilizadas foram similares, comparando-se o teor de umidade de equilíbrio.
ABSTRACT
Relata alguns resultados que têm sido obtidos na elaboraçäo de produtos cárneos com baixo teor de gordura.
