Characterization of sodium alginate-based biodegradable edible film incorporated with Vitis vinifera leaf extract: Nano-scaled by ultrasound-assisted technology

Composite biodegradable edible films of sodium alginate were incorporated with Vitis vinifera (V. vinifera) leaf extract (VVLE) and quercetin to develop antioxidative and antimicrobial food packaging. Ultrasound-assisted (US) and bioactive molecule effects on the characteristics of the developed films were investigated. The films were analyzed for structural and physical properties, as well as antioxidative and antimicrobial activities. The incorporation of VVLE significantly improved the bioactive and antimicrobial activity of the developed films. Thickness, elongation at break, and moisture content of ultrasound-assisted pretreated films significantly decreased in comparison to non-treated samples. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) indicated good compatibility of the components and well-dispersion of bioactive compounds in the alginate matrix. US pretreated film samples had smoother and more homogeneous surfaces than untreated films. The thermal stabilities of films were confirmed with thermogravimetric analysis, which suggested US significantly increased the thermal stability. The biodegradability of the films was demonstrated by soil degradation properties. In particular, the addition of VVLE and application of US pretreatment improved the structural and antimicrobial as well as the antioxidant activities of the developed alginate-based edible films. The overall findings of this study suggest that US pretreatment and VVLE incorporation have a good potential to develop biodegradable edible active films for food packaging

Minimally Processed Refrigerated Fruits and Vegetables

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Protein/polysaccharide conjugation via Maillard reactions in an aqueous media: Impact of protein type, reaction time and temperature

It is generally accepted that protein-polysaccharide interactions improve the functional properties of proteins. One of the main issues, to our knowledge, of the effects of protein type and reaction conditions, is a lack of production of Maillard conjugates. This paper focuses on the effects of protein type and ratio, reaction time and temperature on the protein/polysaccharide conjugation by Maillard reactions in an aqueous media.&nbsp;Response Surface Methodology&nbsp;D-Optimal Design was used to optimize the results. Protein type, protein-polysaccharide ratio, reaction time (min) and temperature (°C) were described as factors, whereas conjugation yield (CY), conjugation efficiency (CE), and protein solubility (PS) were described as responses. The optimized parameters for maximum CE and CY determined were found to be as; reaction temperature, 90&nbsp;°C; reaction time, 60&nbsp;min; protein type, faba bean protein concentrate (FPC), and protein-polysaccharide ratio 1:2. SEM images, FT-IR spectra, amino acid profile, SDS-PAGE and browning index were the analyses conducted for the optimum point (FPC-Carrageenan). Conjugation was achieved successfully by the confirmation of FT-IR results. Browning index and SDS-PAGE results revealed that Maillard reactions were limited in the initial stage of the Schiff base. These findings confirm that FPC was the most suitable protein type for preparing Maillard-glycated conjugates as a promising agent.</p