Antimicrobial and physicochemical characterization of whey protein concentrate edible films incorporated with liquid smoke

A Review of Recent Developments in Edible Films and Coatings-Focus on Whey-Based Materials

Packaging for food products is particularly important to preserve product quality and shelf life. The most used materials for food packaging are plastic, glass, metal, and paper. Plastic films produced based on petroleum are widely used for packaging because they have good mechanical properties and help preserve the characteristics of food. However, environmental concerns are leading the trend towards biopolymers. Films and coatings based on biopolymers have been extensively studied in recent years, as they cause less impact on the environment, can be obtained from renewable sources or by-products, are relatively abundant, have a good coating and film-forming capacity, are biodegradable and have nutritional properties that can be beneficial to human health. Whey protein-based films have demonstrated good mechanical resistance and a good barrier to gases when at low relative humidity levels, in addition to demonstrating an excellent barrier to aromatic compounds and especially oils. The use of whey proteins for films or coatings has been extensively studied, as these proteins are edible, have high nutritional value, and are biodegradable. Thus, the main objective of this document was to review new methodologies to improve the physicochemical properties of whey protein films and coatings. Importance will also be given to the combinations of whey proteins with other polymers and the development of new techniques that allow the manipulation of structures at a molecular level. The controlled release and mass transfer of new biomaterials and the improvement of the design of films and packaging materials with the desired functional properties can increase the quality of the films and, consequently, broaden their applications.

Characterization of ginger starch-based edible films incorporated with coconut shell liquid smoke by ultrasound treatment and application for ground beef

The aim of the present study was to investigate the structural and physicochemical properties of ultrasound-treated ginger starch-based edible films incorporated with coconut shell liquid smoke (CSLS), and determine the inhibitory effect of the films against Escherichia coli O157:H7 in ground beef during the storage at 4 °C. Ultrasound-treated CSLS-ginger starch films presented a better mechanical, barrier, thermal, and antibacterial properties. The antibacterial effect of CSLS against E. coli, S. aureus, E. coli O157:H7, Listeria monocytogenes, Salmonella Enteritidis, and B. cereus increased significantly with ultrasound treatment. The CSLS-films showed antibacterial activity against E. coli O157:H7 without negatively affecting the sensory attributes of ground beef. The films containing 15% CSLS reduced E. coli O157:H7 populations by 1.33 log cfu/g in ground beef during the 12-day-storage. The CSLS-starch films effectively inhibited lipid oxidation in the ground beef samples during the refrigerated storage. These results indicated that ultrasound-treated CSLS-ginger starch film has the application potential as a novel antimicrobial active packaging for proteinous foods.

Natural Antimicrobials as Additives for Edible Food Packaging Applications: A Review

Edible packaging is a swiftly emerging art of science in which edible biopolymers like lipids, polysaccharides, proteins, resins, etc., and other consumable constituents extracted from various non-conventional sources are used alone or imbibed together. Edible packaging with antimicrobial components had led to the development of the hypothesis of active packaging which safeguards the quality of foods as well as health of consumers. Natural antimicrobial agents (NAMAs) like essential oils from spices, bioactive compounds derived from vegetables and fruits, animal and microorganism derived compounds having antimicrobial properties can be potentially used in edible films as superior replcement for synthetic compounds, thus serving the purpose of quality and heath. Most of the natural antimicrobial agents enjoy GRAS status and are safer than their synthetic counterparts. This review focuses on updated literature on the sources, properties and potential applications of NAMAs in the food industry. This review also analyzes the biodegradability and biocompatibility and edibility properties of NAMAs enriched films and it can be concluded that NAMAs are better substitutes but affect the organoleptic as well as the mechanical properties of the films. Despite many advantages, the inclusion of NAMAs into the films needs to be investigated more to quantify the inhibitory concentration without affecting the properties of films and exerting potential antimicrobial action to ensure food safety.

Effects of edible coatings containing acai powder and matcha extracts on shelf life and quality parameters of cooked meatballs

This study was realized to determine the effects of whey protein isolate (5% w/v) based edible coatings (WPC) containing different concentrations (3, 6, 9% w/v) of acai powder extract (AE) and matcha extract (ME) on oxidative and microbial stability of cooked meatballs during storage (14 d at +4 °C or 60 d at -18 °C). The antioxidant analysis of the extracts demonstrated that ME had higher total phenolic content and antioxidant capacity than AE (P < 0.05). Results indicated that WPC containing ME delayed lipid oxidation in meatballs during both refrigerated and frozen storage (P < 0.05). Moreover, the use of AE in WPC suppressed microbial growth during both storage conditions (P < 0.05). The edible coating process had no negative effects (P > 0.05) on color, texture, physicochemical composition, and consumer preferences. This result showed that the use of AE and ME in WPC formulation inhibited lipid oxidation and microbial growth, and had the potential for extending shelf-life of meatballs by preserving the physicochemical properties.

Effects on Surface and Physicochemical Properties of Dielectric Barrier Discharge Plasma-Treated Whey Protein Concentrate/Wheat Cross-Linked Starch Composite Film

Dielectric barrier discharge (DBD) plasma is a new type of polymer surface modification technology. This study is mainly about the changes in film surface structure and physicochemical properties of whey protein concentrate (WPC)/wheat cross-linked starch (WCS) composite films after DBD plasma treatment with different plasma parameters. The results show that the proper plasma treatment parameters (400 W to 60 s) can increase the surface roughness, tensile strength, barrier properties, and thermal stability of the edible film and decrease elongation at break and the water contact angle. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction showed that DBD plasma treatment could increase the content of oxygen-containing groups on the WPC/WCS film surfaces instead of damaging the internal crystal structure. The results showed that use of proper DBD plasma treatment technology has a positive effect on the mechanical and barrier properties and thermal stability of WPC/WCS films. PRACTICAL APPLICATION: DBD plasma treatment can improve the mechanical, barrier, and thermal properties of WPC/WCS films without generating any pollution. The DBD plasma can be potentially applied in the enhancement of edible film properties. WPC/WCS films are more environmentally friendly than plastics and can be a replacement for traditional plastics.