Cellulose nanocrystals (CNCs) loaded alginate films against lipid oxidation of chicken breast

Properties of sodium alginate-based nanocomposite films: Effects of aspect ratio and surface charge of cellulose nanocrystals

Three cellulose nanocrystals (CNCs) were prepared to reinforce sodium alginate (SA) films. This study investigated effects of aspect ratio (L/D) and surface charge of three CNCs (CCNC, MCNC, and WCNC) on the properties of films. At CNC concentrations ≤3 wt%, MCNC, with a medium L/D but the lowest surface charge density among the three CNCs, exhibited the highest efficiency in enhancing the Young's modulus and tensile strength of films. This indicated that, apart from L/D, CNC's surface charge density also affected its reinforcing effects in anionic SA-based films. Compared with other CNCs, MCNC with the lowest charge density exhibited weaker repulsion with SA, potentially contributing to stronger interfacial interactions between them. At concentrations >3 wt%, the reinforcing efficiency of MCNC was extremely close to that of WCNC, which had the highest L/D but medium charge density. This was possibly because, according to SEM results, MCNC with the lowest absolute value of zeta potential aggregated more severely than other CNCs. However, both MCNC and WCNC were consistently more efficient than CCNC. Moreover, FTIR results revealed that WCNC formed more hydrogen bonds with SA than other CNCs. Consequently, adding WCNC was more effective in reducing films' water vapor permeability and hydrophilicity.

Novel ammonia-sensitive sodium alginate-based films containing Co-Imd microcrystals for smart packaging application

Currently, there is an urgent requirement for the fabrication of smart packaging materials that can be applied for the real-time visual monitoring of food freshness. In this research, cubic Co-MOF (Co-Imd) microcrystal with ammonia-sensitivity and antibacterial activity was manufactured and then anchored within sodium alginate (NaAlg) matrix to construct smart packaging materials. The structure, physical and functional performances of NaAlg-based films with different content of Co-Imd (0.5, 1.0 and 2.0 wt% on NaAlg basis) were then evaluated in detail. Results reveal that the incorporated Co-Imd fillers are equally anchored within the NaAlg matrix due to the generation of new hydrogen-bonding interaction, which make an obvious improvement in mechanical strength, toughness, oxygen/water barrier, and UV-blocking ability of the NaAlg film. Moreover, the constructed NaAlg/Co-Imd blend films show superior antibacterial capability, ammonia-sensitivity function as well as color stability. Ultimately, the NaAlg/Co-Imd blend films were successfully utilized for indicating the deterioration of shrimp based on noticeable color alteration, suggesting their tremendous prospects for utilization in smart active packaging. This work offers a facile and efficient method for fabricating novel ammonia-sensitive and long-term color-stable NaAlg-based film materials with improved mechanical strength, toughness, oxygen/water barrier, UV-blocking, and antibacterial performances for smart active packaging application.

Edible Film Casting Techniques and Materials and Their Utilization for Meat-Based Product Packaging

According to a profusion of academic studies on the use of organic materials or biopolymers as key components, the current trajectory of food packaging techniques is showing a positive inclination. Notably, one such biopolymer that has attracted much attention is edible film. The biopolymers that have been stated as constitutive components are composed of polysaccharides, lipids, proteins, or a combination of these, which work together to reinforce one another's properties and create homogenous mixtures. An edible film provides a clear, thin layer that encases foodstuffs, including their packaging. The production and use of edible film have recently been the focus of much research in the field of food polymers. Extending the shelf life of food goods is the goal of this research. Given their great susceptibility to change brought on by outside forces or pollutants, which may result in oxidative rancidity, the proper storage of nutrient-dense food items, particularly meat products, deserves careful study. Many edible films have been found to contain active ingredients, such antimicrobials or antioxidants, that can successfully prevent the spoiling of meat products, a process that can happen in a short amount of time. Surprisingly, a number of scholarly examinations reveal that edible film may be cooked alongside meat because of its organic makeup. We hope that the use of edible film will lead to a more environmentally responsible method of food packaging than has previously been possible.

A pH-sensitive intelligent packaging film harnessing Dioscorea zingiberensis starch and anthocyanin for meat freshness monitoring

Abundant starch was isolated from Dioscorea zingiberensis C.H. Wright, a novel and underutilized industrial crop resource. In this study, an intelligent packaging film able to indicate food freshness was developed and characterized. D. zingiberensis starch (DZS) was bleached first, and its particle size, total starch content, amylose content, and gelatinization temperature were then measured. Butterfly pea (Clitoria ternatea Linn.) flowers were selected as the source of polyphenols, which rendered the prepared film intelligent and progressively blue-violet. SEM and FT-IR analyses showed the homogeneous dispersion of butterfly pea flower extract (BPE) in the film. The BPE-loaded film showed improved flexibility and resistance to UV and oxidation while maintaining sufficient mechanical strength and physical properties. Moreover, the film underwent a distinguishable color change from red to blue-violet and finally to green-yellow with increasing pH from 2 to 13. Similar color alteration also occurred when the film was exposed to ammonia. When the film was used to monitor the freshness of chicken stored at room temperature, it exhibited an obvious color change, implying its deterioration. Therefore, the newly developed BPE-DZS film, which was produced from readily accessible natural substances, can serve as an intelligent packaging material, indicating food freshness and prolonging shelf life.

Development of pullulan-based nanocomposite films reinforced with starch nanocrystals for the preservation of fresh beef

BACKGROUND

Incorporation of polysaccharide-based nanofillers is an effective strategy to fabricate bio-nanocomposite films with preferable mechanical, barrier, and surface hydrophobicity properties compared to pure biopolymer films. The objective of this research is to investigate the influence of starch nanocrystals obtained from native (NSNC) and waxy rice starch (WSNC) on the physical-chemical properties of pullulan-based nanocomposite films and their preservation performance on fresh beef.

RESULTS

Continuous SNCs network structure was observed for pullulan-10% SNCs nanocomposite films, whereas the percolation network of SNCs was destroyed and became no longer continuous with increasing SNCs concentration up to 20% in pullulan films. Among the tested films, pullulan-10% SNCs films showed the highest TS values, lowest WVP and OTR values, due to the formation of percolating SNCs network in pullulan matrix. It is noteworthy that the WVP and OTR values of pullulan-10% WSNC films were significantly lower than that of pullulan-10% NSNC films, probably due to higher hydrophobicity and crystallinity of WSNC compared with NSNC. Beef pieces coated with pullulan-SNCs films had higher L^* and a^* values, lower TVB-N, TBARS, and TVC values during 7 days' storage at 4 °C compared with samples coated with pullulan films.

CONCLUSION

Pullulan-SNCs nanocomposite films, especially pullulan-WSNC films, could be potentially used as a coating material for fresh beef due to their desirable oxygen and water barrier properties. © 2022 Society of Chemical Industry.

Nano-Encapsulated Essential Oils as a Preservation Strategy for Meat and Meat Products Storage

Consumers today demand the use of natural additives and preservatives in all fresh and processed foods, including meat and meat products. Meat, however, is highly susceptible to oxidation and microbial growth that cause rapid spoilage. Essential oils are natural preservatives used in meat and meat products. While they provide antioxidant and antimicrobial properties, they also present certain disadvantages, as their intense flavor can affect the sensory properties of meat, they are subject to degradation under certain environmental conditions, and have low solubility in water. Different methods of incorporation have been tested to address these issues. Solutions suggested to date include nanotechnological processes in which essential oils are encapsulated into a lipid or biopolymer matrix that reduces the required dose and allows the formation of modified release systems. This review focuses on recent studies on applications of nano-encapsulated essential oils as sources of natural preservation systems that prevent meat spoilage. The studies are critically analyzed considering their effectiveness in the nanostructuring of essential oils and improvements in the quality of meat and meat products by focusing on the control of oxidation reactions and microbial growth to increase food safety and ensure innocuity.

Preparation of Edible Films with Lactobacillus plantarum and Lactobionic Acid Produced by Sweet Whey Fermentation

Cheese whey, one of the most abundant by-products of the dairy industry, causes economic losses and pollution problems. In this study, deproteinised sweet whey was fermented by Pseudomonas taetrolens LMG 2336 to produce a prebiotic compound (lactobionic acid, LBA). Endotoxins produced by these microorganisms were successfully removed using microfiltration techniques, allowing the fermented whey permeate to be used in the food industry. The fermented whey permeate was used to develop prebiotic edible films by adding two different concentrations of gelatine (0.45 and 0.9 g gelatine g−1 LBA; LBA45 and LBA90). Furthermore, Lactobacillus plantarum CECT 9567 was added as a probiotic microorganism (LP45 and LP90), creating films containing both a prebiotic and a probiotic. The mechanical properties, water solubility, light transmittance, colour, and microstructure of the films were fully characterised. Additionally, the LBA and probiotic concentration in LP45 and LP90 were monitored under storage conditions. The strength and water solubility of the films were affected by the presence of LBA, and though all these films were homogeneous, they were slightly opaque. In LP45 and LP90, the presence of LBA as a prebiotic improved the viability of L. plantarum during cold storage, compared to the control. Therefore, these films could be used in the food industry to coat different foodstuffs to obtain functional products.

Lignocellulose nanocrystals from pineapple peel: Preparation, characterization and application as efficient Pickering emulsion stabilizers

In this study, the pineapple peel treated with different degrees of delignification was used to isolate lignocellulose nanocrystals (LCNC) by sulfuric acid hydrolysis. Controlling delignification treatments can adjust the morphology and structure of pineapple peel and the retention of lignin, thereby achieving the regulation of the properties of LCNC, such as morphology, crystallinity, hydrophobicity and rheological properties. The results of atomic force microscope (AFM), confocal laser scanning microscopy (CLSM), UV/visible (UV-Vis) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the presence of lignin in LCNC, showing a rod-like structure with the distribution of lignin. Regulating delignification of pineapple peel can adjust the average length (310 ∼ 460 nm), diameter (19 ∼ 38 nm), crystallinity (61% ∼ 71%) and hydrophobicity (contact angle 84° ∼ 60°) of the obtained LCNC by acid hydrolysis, and influence the performance of its stabilized Pickering emulsions. This work confirms that the properties of LCNC can be controlled through adjusting delignification degree, possessing great significance for the high value utilization of lignocellulosic agricultural waste.

Active natural-based films for food packaging applications: The combined effect of chitosan and nanocellulose

This work aimed to evaluate the potential of chitosan/cellulose nanocrystals (CNC) films to be used as active pads for meat packages to prolong its shelf-life and preserve its properties over time. Several CNC concentrations (5, 10, 25, and 50 wt%) were tested and the films were produced by solvent casting. The developed samples were characterized by ATR-FTIR, TGA, FESEM, and XRD. The transparency, antimicrobial, barrier and mechanical properties were also assessed. Finally, the films' ability to prolong food shelf-life was studied in real conditions using chicken meat. CNC incorporation improved the thermal stability and the oxygen barrier while the water vapor permeability was maintained. An enhancement of mechanical properties was also observed by the increase in tensile strength and Young's modulus in chitosan/CNC films. These films demonstrated bactericidal effect against Gram-positive and Gram-negative bacteria and fungicidal activity against Candida albicans. Lastly, chitosan-based films decreased the growth of Pseudomonas and Enterobacteriaceae bacteria in meat during the first days of storage compared to commercial membranes, while chitosan/CNC films reduced the total volatile basic nitrogen (TVB-N), indicating their efficiency in retarding meat's spoilage under refrigeration conditions. This work highlights the great potential of natural-based films to act as green alternatives for food preservation.

Evaluation of Antimicrobial Coatings on Preservation and Shelf Life of Fresh Chicken Breast Fillets Under Cold Storage

Fresh poultry products such as chicken breast are very convenient for consumption due to their availability and nutritional and sensory characteristics but they have a short shelf life (3–5 days) due to their high water activity and propensity to microbial contamination and spoilage. In this work, the characteristics of edible coatings (EC) prepared from various formulations of guar gum (GG) and isolated soy protein were evaluated. From this evaluation, and due to the guar gum EC being the most suitable, antimicrobial coatings were prepared with different proportions of GG, nisin, and oregano oil to determine its effect on shelf life and change in physicochemical and microbiological properties of chicken breast fillets under refrigerated conditions. Fresh samples were coated with a coating-forming solution based on GG and stored at 4 °C for 16 days. During this time, the change in color, firmness, acidity, pH, growth of microorganisms was determined, and sensory tests of appearance, taste, and odor were performed. GG-coated samples retained color and firmness during storage. Likewise, a decrease in weight loss was achieved in the treated samples, and the sensory attributes were preserved compared to the uncoated samples. The application of the coating considerably delayed the growth of microorganisms, increasing the product shelf life (9 days) compared to the control samples (6 days).

Edible and Functionalized Films/Coatings—Performances and Perspectives

In recent years, food packaging has evolved from an inert and polluting waste that remains after using the product toward an active item that can be consumed along with the food it contains. Edible films and coatings represent a healthy alternative to classic food packaging. Therefore, a significant number of studies have focused on the development of biodegradable enveloping materials based on biopolymers. Animal and vegetal proteins, starch, and chitosan from different sources have been used to prepare adequate packaging for perishable food. Moreover, these edible layers have the ability to carry different active substances such as essential oils—plant extracts containing polyphenols—which bring them considerable antioxidant and antimicrobial activity. This review presents the latest updates on the use of edible films/coatings with different compositions with a focus on natural compounds from plants, and it also includes an assessment of their mechanical and physicochemical features. The plant compounds are essential in many cases for considerable improvement of the organoleptic qualities of embedded food, since they protect the food from different aggressive pathogens. Moreover, some of these useful compounds can be extracted from waste such as pomace, peels etc., which contributes to the sustainable development of this industry.

Polysaccharide and Protein Films with Antimicrobial/Antioxidant Activity in the Food Industry: A Review

From an economic point of view, the spoilage of food products during processing and distribution has a negative impact on the food industry. Lipid oxidation and deterioration caused by the growth of microorganisms are the main problems during storage of food products. In order to reduce losses and extend the shelf-life of food products, the food industry has designed active packaging as an alternative to the traditional type. In the review, the benefits of active packaging materials containing biopolymers (polysaccharides and/or proteins) and active compounds (plant extracts, essential oils, nanofillers, etc.) are highlighted. The antioxidant and antimicrobial activity of this type of film has also been highlighted. In addition, the impact of active packaging on the quality and durability of food products during storage has been described.