1,720,998 research outputs found
Properties of Active Levan-Bitter Vetch Protein Films for Potential Use in Food Packaging Applications
No full textζ-potential and Z-average were determined on film-forming solutions of bitter vetch-levan-based films prepared at different ratios in the absence and presence of glycerol as a plasticizer. The casting method was used to obtain manageable films. The results revealed that levan increases the elongation at break of bitter vetch protein films and reduces the tensile strength. The optimal result was obtained through the film that was prepared with the ratio of 50% bitter vetch proteins and 50% levan, in terms of mechanical properties. The surfaces of the prepared films appeared to be more compact and smooth. On increasing the glycerol concentration in the bitter vetch protein-levan films, the oxygen and water vapor permeability increased compared to the control (P < 0.05). Based on the overall results, the reinforcement of bitter vetch proteins with levan at a ratio of 1:1 represents optimal film properties in the presence of a low concentration of glycerol. The proposed film is suggested as an innovative packaging system for beef meat to preserve its quality over time
Use of transglutaminase to reticolate protein componente of hydrocolloid mulching films: preparation, characterization and biodegradability properties
No full textHigher susceptibility to amyloid fibril formation of the recombinant ovine prion protein modified by transglutaminase
No full textBasil (Ocimum basilicum L.) Leaves as a Source of Bioactive Compounds
Get PDFBasil (Ocimum basilicum L.) is an annual spicy plant generally utilized as a flavouring agent for food. Basil leaves also have pharmaceutical properties due to the presence of polyphenols, phenolic acids, and flavonoids. In this work, carbon dioxide was employed to extract bioactive compounds from basil leaves. Extraction with supercritical CO2 (p = 30 MPa; T = 50 °C) for 2 h using 10% ethanol as a cosolvent was the most efficient method, with a yield similar to that of the control (100% ethanol) and was applied to two basil cultivars: “Italiano Classico” and “Genovese”. Antioxidant activity, phenolic acid content, and volatile organic compounds were determined in the extracts obtained by this method. In both cultivars, the supercritical CO2 extracts showed antiradical activity (ABTS●+ assay), caffeic acid (1.69–1.92 mg/g), linalool (35–27%), and bergamotene (11–14%) contents significantly higher than those of the control. The polyphenol content and antiradical activity measured by the three assays were higher in the “Genovese” cultivar than in the “Italiano Classico” cultivar, while the linalool content was higher (35.08%) in the “Italiano Classico” cultivar. Supercritical CO2 not only allowed us to obtain extracts rich in bioactive compounds in an environmentally friendly way but also reduced ethanol consumption
Edible coating from enzymatically reticulated whey protein-pectin to improve shelf life on roasted peanuts
No full textEdible coatings are a viable alternative method to enhance food shelf life that can be designed using different biopolymers. This study evaluated the effect of a whey protein–pectin coating reticulated by microbial transglutaminase (mTG) on improving roasted peanuts’ shelf life. Peroxide value, water content, peanut color, and the solution’s contact angle were studied. The latter was improved by the presence of the enzyme. The results showed that the presence of the coating on the peanut surface reduces the peroxide value and water content, probably as a consequence of an improved barrier effect due to the presence of mTG, which protects the kernel. Enzymatically reticulated whey protein–pectin coatings are a promising alternative to enhance the shelf life of roasted peanut kernels using natural ingredients
Glutamic acid as repeating building block for bio-based films
No full textCommercial inexpensive preparations of poly-γ-glutamic acid were used to obtain films made with a polypeptide constituted by a single repeating unit. The homopolymer was characterized by 1H-NMR spectroscopy and thermogravimetry, as well as by zeta potential and Z-average measurements. Manipulatable materials were obtained by casting film-forming solutions prepared at pH values between 3.0 and 4.0 and containing extensively dialyzed samples of the commercial product. The analysis of the mechanical properties highlighted a marked extensibility and plasticity of the films obtained without plasticizer, even though the addition of low amounts of glycerol (1-4%) was able to further increase these features. The characterization of poly-γ-glutamic acid molecular species, performed by membrane ultrafiltration and size-exclusion chromatography, coupled with triple-detection analysis of the obtained fractions, suggested that biopolymer chain length is responsible not only for its capacity to form film, but also for conferring to the films different features depending on the homopolymer molecular weight
Enzymatic modification of proteins and peptides from oilseeds by-products
No full textNowadays, the worldwide attention on waste reduction is increasing. In this view, the development of new processes is interesting for food industries that aim to reuse wastes both as a food product with added value or for other uses such as edible packaging. Modification of proteins and peptides by transglutaminase represents a suitable way to manipulate polymeric matrices in order to change its physico-chemical and textural properties. For this purpose, whole proteins from de-fatted flour and/or peptides residual from the enzymatic oil extraction from walnut and pumpkin seeds were incubated in the presence of microbial transglutaminase and monitored through SDS-PAGE
Enzymatic study for valorization of plant wastes
No full textPlant wastes represent an interesting source of natural polymers such as cellulose. An enzymatic study was carried out with hydrolytic enzymes in order to obtain a high quality fibers from tomato stalks. The total sugars released in the incubation solution were evaluated with Dubois Method. Cellulose, hemicellulose and lignin percentages of obtained products were determined by Van Soest method. SEM was used to evaluate the quality of fibers. The results demonstrated that tested enzymes can be applied in the tomato stalks pulp processing, to improve lignocellulosic material, which can be used as starting material in different industrial sectors
Preparation and mechanical properties of edible pectin-soy flour films obtained in the absence or presence of transglutaminase.
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