Characterization and application of novel composite films based on soy protein isolate and sunflower oil produced using freeze drying method.

Biocomposite films based on soy protein isolate (SPI) and sunflower oil (SO) were fabricated using freeze drying (FDM) as an innovative approach to formulate a fairly easy-to-apply way, moreover, results were compared with the classic film production method (CM). In FDM, SPI edible film solutions were prepared and dried using freeze drying, and then reconstituted to produce the films. The aim was to specify the effect of both using FDM and concentration of SO (0.05%, 0.10% and 0.15% (w/v)) on the characterization of SPI films via thermal, barrier and morphological analyzes. Reinforced mechanical and good barrier properties were achieved with FDM. By increasing SO content, an improvement of hydrophobic property of the films, a decrease in the swelling values, and a reduction in permeability was observed. The cakes which were wrapped with FDM films showed better textural results than either uncoated cake or the cakes wrapped with CM films.

Production and application of freeze dried biocomposite coating powders from sunflower oil and soy protein or whey protein isolates.

Innovative biocomposite coating powders based on soy protein isolate or whey protein isolate, both containing sunflower oil (SO) were fabricated by freeze drying technique. The influences of concentration of SO and using different protein isolate types on the physicochemical, thermal and morphological properties of the powders were investigated. The Fourier transform infrared spectroscopy and thermal analysis revealed that SO interacted with protein isolates through hydrogen bonding resulted a strong network structure of the powders. It was found that amorphous structure and morphology of the powders was not significantly influenced by oil addition. Moisture content and water activity values of SPI powders were found higher than those of WPI. All powders were wettable, and solubility values were in the range of 91-99%. Preservative-free powders were reconstituted and applied to coat sliced cakes, a bakery product. Coating application showed effective protection on textural structure of cake by high moisture preservation ability.

Characterisation and standardisation of Wangashi cheese production steps.

BACKGROUND: ch aims to assess the effect of Calotropis procera plant stems as a coagulant treatment on the Wangashi cheese in order to characterize and standardize its production. Crude extract obtained from the Calotropis plant stems added to milk powder were used as a solution dissolved at various pH (4-8) and temperature (35-80°C) in order to examine the effect of pH and temperature on milk clotting and proteolytic activities. The pH 5.5 and temperature of 70°C were recorded as optimum pH and temperature. After that the concentration of the crude extract enzyme was assayed to purify it using ammonium sulfate precipitation at various percentage of saturation (20-80%) at determined optimum pH and temperature, whereby the saturation of 70% was detected to be the best because of its high specific activity, yield and purification fold. Two types of Wangashi cheese were produced in laboratory, one using directly the crude extract and the other the purified crude extract from Calotropis procera at optimum condition. Their chemical, textural and color properties were determined using standard methods. A significant difference between parameters tested was observed (p < 0.05). A decrease in moisture content, increase in protein content and also an improvement of color and textural parameters were recorded for the cheese obtained using purified crude extract Calotropis procer. METHODS: earch aims to assess the effect of Calotropis procera plant stems as a coagulant treatment on the Wangashi cheese in order to characterize and standardize its production. Crude extract obtained from the Calotropis plant stems added to milk powder were used as a solution dissolved at various pH (4-8) and temperature (35-80°C) in order to examine the effect of pH and temperature on milk clotting and proteolytic activities. The pH 5.5 and temperature of 70°C were recorded as optimum pH and temperature. After that the concentration of the crude extract enzyme was assayed to purify it using ammonium sulfate precipitation at various percentage of saturation (20-80%) at determined optimum pH and temperature, whereby the saturation of 70% was detected to be the best because of its high specific activity, yield and purification fold. Two types of Wangashi cheese were produced in laboratory, one using directly the crude extract and the other the purified crude extract from Calotropis procera at optimum condition. Their chemical, textural and color properties were determined using standard methods. A significant difference between parameters tested was observed (p < 0.05). A decrease in moisture content, increase in protein content and also an improvement of color and textural parameters were recorded for the cheese obtained using purified crude extract Calotropis procera s. RESULTS: earch aims to assess the effect of Calotropis procera plant stems as a coagulant treatment on the Wangashi cheese in order to characterize and standardize its production. Crude extract obtained from the Calotropis plant stems added to milk powder were used as a solution dissolved at various pH (4-8) and temperature (35-80°C) in order to examine the effect of pH and temperature on milk clotting and proteolytic activities. The pH 5.5 and temperature of 70°C were recorded as optimum pH and temperature. After that the concentration of the crude extract enzyme was assayed to purify it using ammonium sulfate precipitation at various percentage of saturation (20-80%) at determined optimum pH and temperature, whereby the saturation of 70% was detected to be the best because of its high specific activity, yield and purification fold. Two types of Wangashi cheese were produced in laboratory, one using directly the crude extract and the other the purified crude extract from Calotropis procera at optimum condition. Their chemical, textural and color properties were determined using standard methods. A significant difference between parameters tested was observed (p < 0.05). A decrease in moisture content, increase in protein content and also an improvement of color and textural parameters were recorded for the cheese obtained using purified crude extract Calotropis procera staems.

Sorption, diffusivity, permeability and mechanical properties of chitosan, potassium sorbate, or nisin incorporated active polymer films.

The active multilayer packaging films were formed from low-density polyethylene (LDPE) and polyamide containing a 2% antimicrobial agent in one of the LDPE sides of the film (LDPE/polyamide/LDPE-2% antimicrobial agent). The antimicrobial agents used were potassium sorbate (PS-film), nisin (N-film), or chitosan (CTS-film). The effects of antimicrobial incorporation on water vapor permeability (P), diffusivity (D eff ), and solubility (S o and S H ) of the active and control films (LDPE/polyamide/LDPE) were investigated. A dynamic vapor sorption analyzer (DVS) was used to estimate the sorption isotherms of the films at 25 °C. Peleg was found to be the best equation to describe sorption behaviors. The addition of PS and nisin into the film matrix resulted in a lower P than that of the control film. The D eff values of the active films were lower than those of control films, except for the CTS-film. The high water-holding capacity of PS and nisin might limit the D eff of the respective films. It was found that Henry's law was applicable to relate P, D eff , and S o and S H values of the multilayer film [correlation coefficient (r) = 0.909-0.971]. The mechanical and thermal properties of the active films were not significantly affected by the incorporation of PS and nisin (p > 0.05). However, the impact of stress and elongation (transverse direction) on the CTS-film was lower than on other films, which indicated that chitosan improved the mechanical properties of the film.