Selection of a chitosan gelatin-based edible coating for color preservation of beef in retail display

Use of Spectroscopic Techniques to Monitor Changes in Food Quality during Application of Natural Preservatives: A Review

Consumer demand for food of high quality has driven research for alternative methods of food preservation on the one hand, and the development of new and rapid quality assessment techniques on the other hand. Recently, there has been a growing need and interest in healthier food products, which has led to an increased interest in natural preservatives, such as essential oils, plant extracts, and edible films and coatings. Several studies have shown the potential of using biopreservation, natural antimicrobials, and antioxidant agents in place of other processing and preservation techniques (e.g., thermal and non-thermal treatments, freezing, or synthetic chemicals). Changes in food quality induced by the application of natural preservatives have been commonly evaluated using a range of traditional methods, including microbiology, sensory, and physicochemical measurements. Several spectroscopic techniques have been proposed as promising alternatives to the traditional time-consuming and destructive methods. This review will provide an overview of recent studies and highlight the potential of spectroscopic techniques to evaluate quality changes in food products following the application of natural preservatives.

Edible Coating and Pulsed Light to Increase the Shelf Life of Food Products

The application of edible coatings (EC) in combination with pulsed light (PL) treatments represents an emerging approach for extending the shelf life of highly perishable but high value-added products, such as fresh-cut fruits and vegetables. The surface of these products would benefit from the protective effects of ECs and the PL decontamination capability. This review describes in detail the fundamentals of both EC and PL, focusing on the food engineering principles in the formulation and application of EC and the delivery of efficient PL treatments and the technological aspects related to the food characterization following these treatments and discussing the implementation of the two technologies, individually or in combination. The advantages of the combination of EC and PL are extensively discussed emphasizing the potential benefits that may be derived from their combination when preserving perishable foods. The downsides of combining EC and PL are also presented, with specific reference to the potential EC degradation when exposed to PL treatments and the screening effect of PL transmittance through the coating layer. Finally, the potential applications of the combined treatments to food products are highlighted, comparatively presenting the treatment conditions and the product shelf-life improvement.

Application of Nanoemulsions (W/O) of Extract of Opuntia oligacantha C.F. Först and Orange Oil in Gelatine Films

Over the past decade, consumers have demanded natural, completely biodegradable active packaging serving as food containers. Bioactive plant compounds can be added to biopolymer-based films to improve their functionality, as they not only act as barriers against oxidation, microbiological, and physical damage, they also offer functionality to the food they contain. A water-in-oil (W/O) nanoemulsion was produced by applying ultrasound to xoconostle extract and orange oil, and was incorporated into gelatine films in different proportions 1:0 (control), 1:0.10, 1:0.25, 1:0.50, 1:0.75, and 1:1 (gelatine:nanoemulsion). The nanoemulsions had an average size of 118.80 ± 5.50 nm with a Z-potential of −69.9 ± 9.93 mV. The presence of bioactive compounds such as phenols, flavonoids, and betalains in the films was evaluated. The 1:1 treatment showed the highest presence of bioactive compounds, 41.31 ± 3.71 mg of gallic acid equivalent per 100 g (GAE)/100g for phenols, 28.03 ± 3.25 mg of quercetin equivalent per 100 g (EQ)/100g flavonoids and 0.014 mg/g betalains. Radical inhibition reached 72.13% for 2,20-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and 82.23% for 1,1-diphenyl-2-picrylhydrazyl (DPPH). The color of the films was influenced by the incorporation of nanoemulsions, showing that it was significantly different (p < 0.05) to the control. Mechanical properties, such as tensile strength, Young’s modulus, and percentage elongation, were affected by the incorporation of nanoemulsified bioactive compounds into gelatine films. The obtained films presented changes in strength and flexibility. These characteristics could be favorable as packaging material.

Influence of anise (Pimpinella anisum L.) essential oil on the microbial, chemical, and sensory properties of chicken fillets wrapped with gelatin film

The present study aimed to develop a novel active edible film based on gelatin incorporated with 0, 0.3, 0.6, and 0.9% w/w anise essential oil as a natural preservative and investigate the shelf life extension potential of chicken fillets during 12 days of refrigerated storage. The chicken fillets were wrapped with the essence-free and anise essential oil-loaded gelatin films, and microbial counts, chemical and sensory tests were surveyed during chilled storage. Results showed that aerobic mesophilic bacteria and Pseudomonas spp counts significantly decreased at all levels of anise essential oil during the first week of storage, while psychrotrophs, yeasts, and molds numbers began to reduce at concentrations of 0.6 and 0.9% from day 6. The using of anise essential oil caused a significant decrease of chemical parameters of chicken fillets, and the values of pH, peroxide, thiobarbituric acid reactive substance, and total volatile basic-nitrogen reached from 7.42, 5.7 meq/kg, 2.21 mg malondialdehyde/kg, and 24.94 mg N/100 g for the essence-free wrapped samples to 4.8, 6.35 meq/kg, 1.73 mg malondialdehyde/kg, and 18.78 mg N/100 g for the ones wrapped with 0.9% anise essential oil-loaded gelatin films at the end of storage day. In conclusion, application of gelatin films loaded with 0.6 and 0.9% anise essential oil can be advised for wrapping chicken fillets to prolong the shelf life for at least one week.

Effectiveness of bacterial cellulose in controlling purge accumulation and improving physicochemical, microbiological, and sensorial properties of vacuum-packaged beef

The application of bacterial cellulose (BC) as a wrapping material for vacuum-packaged beef was studied and compared against unwrapped beef for up to 3 weeks. The impact of BC wrap on the weight loss, purge accumulation, and drip loss were assessed along with low-field nuclear magnetic resonance, physicochemical, microbiological, and sensorial evaluations. The BC wrap significantly (P < 0.05) reduced purge accumulation in vacuum packages which was confirmed by an increased swelling ratio and scanning electron microscopy images. Colorimetric measurements showed significantly (P < 0.05) increased redness and yellowness values in wrapped samples compared to unwrapped samples. BC wrap did not affect pH, tenderness, and odor of meat, but significantly (P < 0.05) increased lipid oxidation, and numbers of lactic acid bacteria and Brochothrix thermosphacta counts. This study shows that BC wrap has potential as a purge absorbent in vacuum packaged meat. PRACTICAL APPLICATION: Bacteria cellulose has good water holding capacity that can be utilized to absorb purge exudate from beef. It helps to improve the appearance and consequently consumer acceptance of vacuum packed beef.

Quality retention and shelf life extension of fresh beef using Lepidium sativum seed mucilage-based edible coating containing Heracleum lasiopetalum essential oil: an experimental and modeling study

The instability and strong flavor or odor of essential oils (EO) limit their direct incorporation into food products. In this study, the antioxidant and antimicrobial Heracleum lasiopetalum essential oil (HLEO) was added to Lepidium sativum seed mucilage (LSSM) solution at four concentrations (0, 0.5, 1, and 1.5%) to develop a novel edible coating and expand its food application. HLEO-loaded LSSM coating was then used to improve the shelf life and quality of beef as a model food system. The coated and control beef samples were periodically analyzed for physicochemical analysis, microbiological, and sensory characteristics over a period of 9 days at 4 °C. The HLEO-enriched LSSM coating, particularly 1.5% loaded one resulted in a significant (p < 0.05) increase in oxidative and microbiological stability and overall acceptance of the beef samples, compared to the control counterpart. HLEO-loaded LSSM coating, therefore, provides a promising alternative to preserve the meat products under cold storage.

Multifunctional betanin nanoliposomes-incorporated gelatin/chitosan nanofiber/ZnO nanoparticles nanocomposite film for fresh beef preservation

The objective of this study was to fabricate betanin nanoliposomes incorporated gelatin/chitosan nanofiber/ZnO nanoparticles bionanocomposite film (G/CH NF/ZnO NPs/B NLPs) and investigate its effects on the preservation of fresh beef. The scanning electron microscopy image of nanocomposite film displayed a good inter-connective porous morphology. Fourier transform infrared and X-ray diffraction analysis confirmed the formation of new hydrogen bonds and enhanced crystallinity through the addition of CH NF, ZnO NPs, and B NLPs. The G/CH NF/ZnO NPs/B NLPs film exhibited satisfactory mechanical properties and high surface hydrophobicity (water contact angle = 92.49 ± 3.71°). The incorporation of ZnO NPs and B NLPs in the nanocomposite film provided high antibacterial activity and DPPH inhibition activity (53.02 ± 3.26%). The growth of inoculated bacteria, lipid oxidation, and the changes in the pH and color quality of the beef samples were controlled by packaging with the fabricated film. In conclusion, the G/CH NF/ZnO NPs/B NLPs nanocomposite has a high potential for meat preservation.

The effects of gelatin-CMC films incorporated with chitin nanofiber and Trachyspermum ammi essential oil on the shelf life characteristics of refrigerated raw beef

The effects of gelatin-carboxymethyl cellulose (Gel-CMC) based films containing chitin nano fiber (CHNF) and Trachyspermum ammi essential oil (Ajowan), on the shelf life extension of the raw beef at refrigerated temperature (4 °C) over a 12-day period were evaluated. Ajowan essential oil (AJEO) and CHNF were added to the films at 0.24, 0.64 and 1% v/v; and 2 and 4 wt%, respectively. The microbiological (total viable count, psychrotrophic count, Pseudomonas spp., Staphylococcus aureus, lactic acid bacteria, molds and yeasts), the chemical (pH, thiobarbituric acid and total volatile basic nitrogen), color and sensory properties of the packaged samples were evaluated periodically. Bacteria grew the most quickly in the control samples, followed by those wrapped with the Gel-CMC films; The lowest microbial counts, the least change in the chemical properties and the highest sensory scores after 12 days of storage were obtained for the samples wrapped in the films incorporated with 1% AJEO and 4 wt% CHNF.

Food Safety through Natural Antimicrobials

Microbial pathogens are the cause of many foodborne diseases after the ingestion of contaminated food. Several preservation methods have been developed to assure microbial food safety, as well as nutritional values and sensory characteristics of food. However, the demand for natural antimicrobial agents is increasing due to consumers' concern on health issues. Moreover, the use of antibiotics is leading to multidrug resistant microorganisms reinforcing the focus of researchers and the food industry on natural antimicrobials. Natural antimicrobial compounds from plants, animals, bacteria, viruses, algae and mushrooms are covered. Finally, new perspectives from researchers in the field and the interest of the food industry in innovations are reviewed. These new approaches should be useful for controlling foodborne bacterial pathogens; furthermore, the shelf-life of food would be extended.

Effect of sodium alginate and carboxymethyl cellulose edible coating with epigallocatechin gallate on quality and shelf life of fresh pork

The active edible coatings were prepared by incorporating epigallocatechin gallate (EGCG) into sodium alginate (SA) and carboxymethyl cellulose (CMC) to investigate the effect of SA-CMC-EGCG coatings on quality and shelf life of fresh pork stored at 4 ± 1 °C for 7 days. The antioxidant effects against lipid oxidation (TBARS), total volatile basic nitrogen (TVB-N) and antimicrobial activity against total viable counts (TVC) were analyzed. Besides, the changes in color parameters and sensory attributes of all pork samples were evaluated. The results showed that fresh pork coated with SA-CMC edible coating with EGCG had a significant inhibitory effect on its microbial growth (P < 0.05), lipid oxidation and TVB-N. SA-CMC-EGCG also increased the L* value and maintained a* value of pork during storage. Besides, the sensory scores of pork samples coated with SA-CMC-EGCG were significantly improved (P < 0.05). Therefore, using SA-CMC-EGCG edible coating could prevent decay and significantly increase the shelf life of fresh pork.

Optimization of Processing Conditions of Chinese Smoke-cured Bacon (Larou) with a New Natural Coating Solution during Storage Period

The study aims to determine the optimum sterilization rate and water activity of Chinese traditional smoke-cured bacon product (Larou) in the preservation with natural coating solution. With the response surface methodology (RSM), we analyzed 3 factors of processing conditions (the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan) and 2 response factors (sterilization rate and water activity). Sterilization rate and water activity of Larou were largely affected by the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan. The final optimum concentrations of lysozyme, sodium alginate, and chitosan were 0.09, 1.40, and 1.60% and realized the high sterilization rate. Water activity of sliced Larou was significantly correlated with the sterilization rate. Low-field nuclear magnetic resonance analysis verified the optimum processing conditions. The coating resulted in 99.69% rate of reducing bacteria after 30-day storage. The data of the total number of colony, peroxidation value, moisture content, pH, and sensory evaluation provided the theoretical basis for extending the shelf life of Chinese traditional smoke-cured bacon product (Larou) with natural coating solution.

Addition of herbal extracts to the Holstein-Friesian bulls' diet changes the quality of beef

Twenty four Holstein-Friesian bulls were randomly assigned to one of three dietary treatments: a control diet, diet O (supplemented with Optirum herbal extracts improving the functioning of the gastrointestinal tract of cattle), and diet OS (containing two herbal preparation: Optirum and Stresomix, used to reduce stress). The quality of longissimus lumborum (LL) and semimembranosus (SM) muscles were determined after 14 days of wet ageing. The diet influenced proximate composition, pH, water holding capacity, colour, shear force and some sensory quality attributes of beef, although the influence depended on the muscle type. The supplementation of the bulls' diet with two herbal preparations (OS diet) had a beneficial impact on technological properties and sensory tenderness of LL muscles. The herbal extracts O and OS had no negative effect on lipid oxidation or the sensory attributes of beef. Thus, it is recommended to use a combination of these two products in cattle feeding.

Meat packaging solutions to current industry challenges: A review

Many advances have occurred in the field of smart meat packaging, and the potential for these to be used as tools that respond to challenges faced by industry is exciting. Here, we review packaging solutions to several immediate concerns, encompassing dark cutting, purge and yield losses, product traceability and provenance, packaging durability, microbial spoilage and safety, colour stability, environmental impacts, and the preservation of eating quality. Different active and intelligent packaging approaches to each of these were identified and are discussed in terms of their usefulness - to processors, retailers and/or consumers. From this, it became apparent that prior to selecting a packaging solution, industry should first define their criteria for success (e.g. How much purge is too much? What is a reasonable shelf-life to facilitate product turnover? Is the customer willing to pay for this?), and understand that packaging is not the sole solution, but acts as part of a holistic response to these issues.

Clove and rosemary essential oils and encapsuled active principles (eugenol, thymol and vanillin blend) on meat quality of feedlot-finished heifers

Forty Nellore heifers were fed (73days) with different diets: with or without essential oils (clove and/or rosemary essential oil) and/or active principle blend (eugenol, thymol and vanillin). The pH, fat thickness, marbling, muscle area and water losses (thawing and drip) were evaluated 24h post mortem on the Longissimus thoracis, and the effects of aging (14days) was evaluated on the meat cooking losses, color, texture and lipid oxidation. Antioxidant activity was also evaluated. Treatments had no effect (P>0.05) on pH, fat thickness, marbling, muscle area, thawing and drip losses. However, treatments affected (P<0.05) cooking losses, color, texture and lipid oxidation. The diets with essential oil and the active principle blend reduced the lipid oxidation and reduced the color losses in relation to control diet. Aging affected (P<0.05) texture and lipid oxidation. The essential oil and active principles or its blend have potential use in animal feed aiming to maintain/improve meat quality during shelf-life.

Gelatin-Based Films and Coatings for Food Packaging Applications

This review discusses the latest advances in the composition of gelatin-based edible films and coatings, including nanoparticle addition, and their properties are reviewed along their potential for application in the food packaging industry. Gelatin is an important biopolymer derived from collagen and is extensively used by various industries because of its technological and functional properties. Nowadays, a very wide range of components are available to be included as additives to improve its properties, as well as its applications and future potential. Antimicrobials, antioxidants and other agents are detailed due to the fact that an increasing awareness among consumers regarding healthy lifestyle has promoted research into novel techniques and additives to prolong the shelf life of food products. Thanks to its ability to improve global food quality, gelatin has been particularly considered in food preservation of meat and fish products, among others.

Cross-linked alginate/chitosan polyelectrolytes as carrier of active compound and beef color stabilizer

The aim of this work was to develop polyelectrolyte material suitable for active beef steaks coatings, by complexation of chitosan (CH) and sodium alginate (ALG) in a broad range of alginate/chitosan ratios (R). The rheological analysis confirmed significant effect of polymers ratios on the physical properties of sodium alginate-chitosan (ACH) hydrosols. The shear thinning non-Newtonian nature, thixotropic behavior and gel-like structure of solutions were displayed. Obtained complexes possess DPPH radical scavenging activity corresponding to 5.33, 17.06 and 41.41μMTrolox/ml for 0ppm, 500ppm and 1000pmm of sodium erythorbate dose, respectively. Application of ACH hydrosols enriched with 1000ppm of sodium erythorbate enhanced redness and color stability of beef steaks during storage (∆E after 2-weeks of storage=1.44±0.08) compared to uncovered beef (∆E after 2-weeks of storage=3.53±0.13). The limited solubility in range of 0%-54.56% as well as favorable wetting properties (contact angle between 45°-66°) of polyelectrolyte ACH films were obtained.

Effect of Edible and Active Coating (with Rosemary and Oregano Essential Oils) on Beef Characteristics and Consumer Acceptability

The effects of an alginate-based edible coating containing natural antioxidants (rosemary and oregano essential oils) on lipid oxidation, color preservation, water losses, texture and pH of beef steaks during 14 days of display were studied. The essential oil, edible coating and beef antioxidant activities, and beef consumer acceptability were also investigated. The edible coatings decreased lipid oxidation of the meat compared to the control. The coating with oregano was most effective (46.81% decrease in lipid oxidation) and also showed the highest antioxidant activity. The coatings significantly decreased color losses, water losses and shear force compared to the control. The coatings had a significant effect on consumer perception of odor, flavor and overall acceptance of the beef. In particular, the oregano coating showed significantly high values (approximately 7 in a 9-point scale). Active edible coatings containing natural antioxidants could improve meat product stability and therefore have potential use in the food industry.

Physicochemical Properties of Biopolymer Hydrogels Treated by Direct Electric Current

The objective of this study was to evaluate the changes within the physicochemical properties of gelatine (2%; 4%; 8%), carrageenan (1.5%; 2%; 2.5%) and sodium alginate (0.75%; 1%; 1.25%) hydrogels with different sodium chloride concentrations that were triggered by applying direct current (DC) of 400 mA for a duration of five minutes. There were three types of gels prepared for the purpose of the study: C, control; H, gels on the basis of hydrosols that were treated with DC; and G, gels treated with DC. In the course of the study, the authors carried out the following analyses: Texture Profile Analysis (TPA), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Swelling Ratio (SR). Furthermore, the color and pH of hydrogels were measured. The FTIR spectra showed that the structures of gelatine, carrageenan and sodium alginate do not significantly change upon applying DC. The results of TPA, SR, color and pH measurement indicate that hydrogels' properties are significantly dependent on the type of polymer, its concentration and the type of the gel. By changing those parameters, the characteristics of such gels can be additionally tuned, which extends their applicability, e.g., in the food industry. Moreover, the analysis revealed that SR of H gel gelatine after 72 h of storage was 1.84-times higher than SR of the control sample, which indicated that this gel may be considered as a possible component for wound dressing materials.