Water Vapor Permeability of Caseinate‐Based Edible Films as Affected by pH, Calcium Crosslinking and Lipid Content
ABSTRACT Edible films were cast from solutions of sodium or calcium caseinate and from emulsions of these proteins with acetylated monoglyceride, beeswax, and stearic acid. The water vapor permeabilities of the films were evaluated at 25°C using the ASTM E96–80 method, modified to calculate the % relative humidity at the film underside. Adjustment to pH 4.6 (isoelectric point), calcium ion crosslinking and combined effects of calcium ascorbate buffer (pH 4.6) reduced water vapor permeability of sodium caseinate films by 36%, 42%, and 43%, respectively. Calcium caseinate-beeswax emulsion films had water vapor permeabilities up to 90% lower than pure sodium caseinate films. Water vapor permeability varied by a factor of two depending on emulsion film orientation, indicating nonisotropic structure.
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ABSTRACT: Edible film is a packaging system that can eliminate or inhibit spoilage and pathogenic microorganisms, as carriers of antimicrobial compounds. It constitutes an approach for incorporating plant oils. In this study, antimicrobial activity, mechanical, barrier properties of cassava starch/pectin composite film have been studied by incorporating it with 1.5% of various types of oils (Laurus nobilis L. oil, Nigella sativa L. oil and oleic acid) as a natural antibacterial agent against pathogenic bacteria: Escherichia coli, Salmonella enteritidis, Staphylococcus aureus and Pseudomonas aeruginosa based on the clear inhibition zone exhibited which is evaluated in film. The suitable ratio of cassava starch/pectin at (1.5:1.5%w/v) has been used for film-forming solution throughout the experiment. Glycerol (1.5%v/w) is added to the blending compositions which act to maintain film integrity and to avoid pores and crack. Thickness and colour of films are affected (PB0.05) by the incorporated with various types of oils. The effects of various types of oils on the mechanical and barrier properties have been investigated. Tensile strength of the films is significantly decreased (PB0.05), while the elongation significantly increased, also the water vapour permeability and solubility in the water significantly decreased. The overall effect of novel L. nobilis L. oil followed by N. sativa L. oil is greater than oleic acid and control sample.Food and Agricultural Immunology 01/2013; 24(2):241-254. · 0.73 Impact Factor
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ABSTRACT: Edible coatings are an environmentally friendly technology that is applied on many products to control moisture transfer, gas exchange or oxidation processes. Edible coatings can provide an additional protective coating to produce and can also give the same effect as modified atmosphere storage in modifying internal gas composition. One major advantage of using edible films and coatings is that several active ingredients can be incorporated into the polymer matrix and consumed with the food, thus enhancing safety or even nutritional and sensory attributes. But, in some cases, edible coatings were not successful. The success of edible coatings for fresh products totally depends on the control of internal gas composition. Quality criteria for fruits and vegetables coated with edible films must be determined carefully and the quality parameters must be monitored throughout the storage period. Color change, firmness loss, ethanol fermentation, decay ratio and weight loss of edible film coated fruits need to be monitored. This review discusses the use of different edible coatings (polysaccharides, proteins, lipids and composite) as carriers of functional ingredients on fresh fruits and vegetables to maximize their quality and shelf life. This also includes the recent advances in the incorporation of antimicrobials, texture enhancers and nutraceuticals to improve quality and functionality of fresh-cut fruits. Sensory implications, regulatory status and future trends are also reviewed.Critical reviews in food science and nutrition 01/2013; 53(5):435-50. · 3.73 Impact Factor
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ABSTRACT: Sorghum wax, sorbitol, glycerin, and soy protein isolate (SPI) composite films were prepared. Effects of sorghum wax, sorbitol, and glycerin concentrations on various films were evaluated using response surface methodology. All independent variables significantly (P<0.05) affected film water vapor permeability (WVP), tensile strength (TS), elongation at break (E), total color difference, and total soluble matter (TSM). Increasing the sorghum wax concentration decreased WVP and E. As sorbitol content increased in the composite films, WVP and TS increased. Sorbitol had a critical point of 2–5 g/5 g SPI for low values of TSM. The addition of sorbitol contributed more to the properties of the film than did glycerin.Journal of Oil & Fat Industries 04/2012; 80(1):71-76. · 1.59 Impact Factor