Preparation and characterization of milk protein films and their application for packaging of Cheddar cheese

Abstract

Casein and whey protein concentrate (WPC) films, plasticized with glycerol and sorbitol independently, were prepared by casting. The film thickness, water vapour and oxygen permeation and tensile and moisture sorption properties of the films were determined. The tensile strength (TS), tensile strain (TE) and elastic modulus (EM) of the films ranged from 0.71 to 4.58 MPa, 19.22 to 66.63 % and 2.05 to 6.93 MPa, respectively. The film properties were influenced by the type of biopolymer (casein and whey protein concentrate), plasticizer and its concentration. Increasing the plasticizer concentration, increased the film thickness, TE and water vapour permeability (WVP), but decreased the TS and EM. As the concentration of plasticizer increased to the highest level, the film thickness increased from 0.168 to 0.305 mm for glycerol-plasticized films and from 0.251 to 0.326 mm for sorbitol-plasticized films. The film thickness increased because the amount of plasticizer in the film network increased and the amount of biopolymer remained same. Casein films showed superior tensile properties as compared to WPC films. The WVP of both casein and WPC films lied between 3.87 and 13.97 g.mm./(m 2 .h.kPa). The moisture sorption isotherms of both films were typical of high-protein material, and were adequately described by the GAB model. The oxygen permeability of casein films was relatively lower than that of WPC films, regardless of the plasticizer used. The sensory data revealed that the organoleptic quality of Cheddar cheese was unaffected by milk-protein film packaging.

Compressive strengths of PEG gels with glycerol and bioglass particles

“…In other studies, sorbitol plasticizer also increased the strength properties of structural proteins films. 28,29 Glycerol, propylene glycol, and PEG 8000 (PEG with MW = 8000) also exhibited plasticizing effects at low saturation levels: 25%, 14%, and 50%, respectively…”

Peynirin Raf Ömrünü Uzatmada Bal Mumu Kaplamaların Kullanılması

“…The coatings and edible films, obtained from food-grade additives and edible biopolymers, might protect cheese from physical, chemical and biological deterioration as well as improve visual and tactile features. It has been observed that edible films are effective to control microbial growth on the surface, moisture migration, oxidation of nutrients and light-induced chemical changes (Ramos et al 2012;Mastromatteo et al 2013;Wagh et al 2014) (Table 2). …”

Development and characterization of poly(vinyl alcohol) and casein blend films

“…Amongst these natural sources, animal and vegetable proteins are used as bio‐plastics. Their film‐forming properties make proteins attractive for various applications . Proteins consist of several amino acid monomers which are linked by peptide bonds and form the primary structure of the protein.…”

“…It has some unique properties for food packaging applications such as nutritional value and sensory properties. CA tends to easily form films due to its open secondary structure and weak intermolecular interactions like hydrogen, electrostatic and hydrophobic bonds in its structure . Films made from CA can provide a barrier to gases (O 2 , CO 2 ) and various non‐polar molecules because it includes several amino and hydroxyl functional groups, and has lower free volume.…”

“…Despite many advantages, there are some limitations of CA films such as brittleness and high water sensitivity. To overcome these limitations CA can be blended with plasticizers and biosynthetic polymers …”