The Preservation Effect of Chitosan-hawthorn Leaf Extract Coating on Strawberries.

Strawberries rapidly deteriorate postharvest, necessitating effective measures to extend their shelf life. This study focused on developing an eco-friendly chitosan-based protective film for strawberry preservation. Strawberries were treated with a coating solution containing varying concentrations of hawthorn leaf extract (HLE) (0.4%, 0.7%, and 1.0%), 1.5% chitosan (CH), and 1% acetic acid. The results demonstrated that coating strawberry fruit with 1% CH-HLE notably delayed fruit spoilage. In-depth analysis revealed that, compared with the uncoated strawberry fruits, the 1% CH-HLE coating effectively reduced weight loss, the respiration intensity, malondialdehyde (MDA) levels, and superoxide anion (O2·-) production. Additionally, the coated strawberries exhibited improved firmness, total soluble solids (TSS), vitamin C (Vc) content, titratable acidity (TA), and total phenolic compound (TPC) content. The enzyme activities of superoxide dismutase (SOD) and catalase (CAT) in the CH-HLE-coated strawberries were greater than those in their uncoated counterparts. The application of a 1% CH-HLE coating successfully delayed spoilage and extend the shelf life of the strawberries by approximately 4-5 days. These findings suggest that CH-HLE has significant potential as a resource for protecting fruits and vegetables, offering an environmentally sustainable solution for postharvest preservation.

Xanthan gum coatings augmented with lemongrass oil preserve postharvest quality and antioxidant defence system of Kinnow fruit under low-temperature storage.

Kinnow mandarin is an important citrus fruit that undergoes various postharvest qualitative losses. Therefore, the present study aimed to investigate the effect of polysaccharide-based xanthan gum (XG) coatings and lemongrass essential oil (LG) on the nutritive quality of Kinnow mandarins stored at 5-7 °C, 90-95 % RH for 75 days. The results revealed that in comparison to control the coatings maintained the fruit titratable acidity (TA), soluble solid content (SSC), ascorbic acid (AsA) content, total flavonoid content (TFC), and juice content, along with reduced weight loss and spoilage incidence. The coated fruits also exhibited higher sensory quality, total antioxidant activity (TAA), and activities of enzymes; catalase (CAT), peroxidase (POD), and phenylalanine ammonia-lyase (PAL). At the end of storage, the fruits coated with XG 1.0 % + LG 1.0 % exhibited maximum TA (0.69 %), AsA content (203.5 mg L-1), and TFC (0.21 mg g-1) with minimum weight loss (7.57 %) and spoilage (3.01 %) and SSC (11.87 %). The scanning electron microscopic (SEM) images of the coated fruits also exhibited smooth surfaces with closed stomata pores. Overall, XG 1.0 % + LG 1.0 % proved as a potential postharvest treatment for maintaining the nutritive quality of Kinnow under low-temperature storage.

Exploring the potential of pullulan-based films and coatings for effective food preservation: A comprehensive analysis of properties, activation strategies and applications.

Pullulan is naturally occurring polysaccharide exhibited potential applications for food preservation has gained increasing attention over the last half-century. Recent studies focused on efficient preservation and targeted inhibition using active composite ingredients and advanced technologies. This has led to the emergence of pullulan-based biofilm preservation. This review extensively studied the characteristics of pullulan-based films and coatings, including their mechanical strength, water vapor permeability, thermal stability, and potential as a microbial agent. Furthermore, the distinct characteristics of pullulan, production methods, and activation strategies, such as pullulan derivatization, various compounded ingredients (plant extracts, microorganisms, and animal additives), and other technologies (e.g., ultrasound), are thoroughly studied for the functional property enhancement of pullulan-based films and coatings, ensuring optimal preservation conditions for diverse food products. Additionally, we explore hypotheses that further illuminate pullulan's potential as an eco-friendly bioactive material for food packaging applications. In addition, this review evaluates various methods to improve the efficiency of the film-forming mechanism, such as improving the direct coating process, bioactive packaging films, and implementing layer-by-layer coatings. Finally, current analyses put forward suggestions for future advancement in pullulan-based bioactive films, with the aim of expanding their range of potential applications.

Curcumin-mediated photodynamic treatment extends the shelf life of salmon (Salmo salar) sashimi during chilled storage: Comparisons of preservation effects with five natural preservatives.

The impact of curcumin-mediated photodynamic treatment (PDT) on the microbiological, physicochemical and sensory qualities of salmon sashimi has not been explored. Herein, this study aimed to evaluate the effects of PDT on the shelf-life quality of ready-to-eat salmon fillets during chilled storage (4 °C) in comparison with five widely investigated natural extracts, including cinnamic aldehyde, rosmarinic acid, chlorogenic acid, dihydromyricetin and nisin. From a microbial perspective, PDT exhibited outstanding bacterial inhibition, the results of total viable counts, total coliform bacteria, psychrotrophic bacteria, Pseudomonas spp., Enterobacteriaceae family, and H2S-producing bacteria were notably inactivated (p < 0.05) to meet the acceptable limits by PDT in comparison with those of the control group and natural origin groups, which could extend the shelf-life of salmon fillets from<6 days to 10 days. In the alteration of physicochemical indicators, PDT and natural extracts were able to maintain the pH value and retard lipid oxidation in salmon fillets, while apparently slowing the accumulation (p < 0.05) of total volatile basic nitrogen and biogenic amines, especially the allergen histamine, which contrary to with the variation trend of spoilage microbiota. In parallel, PDT worked effectively (p < 0.05) on the breakdown of adenosine triphosphate and adenosine diphosphate to maintain salmon fillet freshness. Additionally, the physical indicators of texture profile and color did not have obvious changes (p < 0.05) after treated by PDT during the shelf life. Besides, the sensory scores of salmon samples were also significantly improved. In general, PDT not only has a positive effect on organoleptic indicators but is also a potential antimicrobial strategy for improving the quality of salmon sashimi.

On the evaluation of the antimicrobial effect of grape seed extract and cold atmospheric plasma on the dynamics of Listeria monocytogenes in novel multiphase 3D viscoelastic models.

The demand for products that are minimally processed and produced in a sustainable way, without the use of chemical preservatives or antibiotics have increased over the last years. Novel non-thermal technologies such as cold atmospheric plasma (CAP) and natural antimicrobials such as grape seed extract (GSE) are attractive alternatives to conventional food decontamination methods as they can meet the above demands. The aim of this study was to investigate the microbial inactivation potential of GSE, CAP (in this case, a remote air plasma with an ozone-dominated RONS output) and their combination against L. monocytogenes on five different 3D in vitro models of varying rheological, structural, and biochemical composition. More specifically, we studied the microbial dynamics, as affected by 1 % (w/v) GSE, CAP or their combination, in three monophasic Xanthan Gum (XG) based 3D models of relatively low viscosity (1.5 %, 2.5 % and 5 % w/v XG) and in a biphasic XG/Whey Protein (WPI) and a triphasic XG/WPI/fat model. A significant microbial inactivation (comparable to liquid broth) was achieved in presence of GSE on the surface of all monophasic models regardless of their viscosity. In contrast, the GSE antimicrobial effect was diminished in the multiphasic systems, resulting to only a slight disturbance of the microbial growth. In contrast, CAP showed better antimicrobial potential on the surface of the complex multiphasic models as compared to the monophasic models. When combined, in a hurdle approach, GSE/CAP showed promising microbial inactivation potential in all our 3D models, but less microbial inactivation in the structurally and biochemically complex multiphasic models, with respect to the monophasic models. The level of inactivation also depended on the duration of the exposure to GSE. Our results contribute towards understanding the antimicrobial efficacy of GSE, CAP and their combination as affected by robustly controlled changes of rheological and structural properties and of the biochemical composition of the environment in which bacteria grow. Therefore, our results contribute to the development of sustainable food safety strategies.

Packaging films based on biopolymers from seafood processing wastes: Preparation, properties, and their applications for shelf-life extension of seafoods-A comprehensive review.

Biopolymers derived from seafood processing byproducts are used to prepare active and biodegradable films as the packaging of food products. These films possess bioactivities to enhance the shelf life of packed foods by proactively releasing antimicrobial/antioxidative agents into the foods and providing sufficient barrier properties. Seafood processing byproducts are an eminent source of valuable compounds, including biopolymers and bioactive compounds. These biopolymers, including collagen, gelatin, chitosan, and muscle proteins, could be used to prepare robust and sustainable food packaging with some antimicrobial agents or antioxidants, for example, plant extracts rich in polyphenols or essential oils. These active packaging are not only biodegradable but also prevent the deterioration of packed foods caused by spoilage microorganisms as well as chemical deterioration. Seafood discards have a promising benefit for the development of environmentally friendly food packaging systems via the appropriate preparation methods or techniques. Therefore, the green packaging from seafood leftover can be better exploited and replace the synthetic counterpart.

Eco-sustainable coatings based on chitosan, pectin, and lemon essential oil nanoemulsion and their effect on strawberry preservation.

Films and coatings manufactured with bio-based renewable materials, such as biopolymers and essential oils, could be a sustainable and eco-friendly alternative for protecting and preserving agricultural products. In this work, we developed films and coatings from pectin and chitosan to protect strawberries (Fragaria x ananassa Duch.) from spoilage and microbial contamination. We developed three coatings containing equal amounts of glycerol and Sicilian lemon essential oil (LEO) nanoemulsion. We identified seventeen chemicals from LEO by GC-MS chromatogram, including d-limonene, α-Pinene, ß-Pinene, and γ-Terpinene. The pectin and chitosan coatings were further characterized using different physicochemical, mechanical, and biological methods. The films demonstrated satisfactory results in strength and elongation at the perforation as fruit packaging. In addition, the coatings did not influence the weight and firmness of the strawberry pulps. We observed that 100 % essential oil was released in 1440 min resulting from the erosion process. Also, the oil preserved the chemical stability of the films. Antioxidant activity (AA), measured by Electron Paramagnetic Resonance (EPR), showed that the coatings loaded with 2 % LEO nanoemulsion (PC + oil) showed that almost 50 % of AA from LEO nanoemulsion was preserved. The chitosan and the pectin-chitosan coatings (PC + oil) inhibited filamentous fungi and yeast contaminations in strawberries for at least 14 days, showing a relationship between the AA and antimicrobial results.

Chitosan coating with grape peel extract: A promising coating to enhance the freeze-thaw stability of beef.

This study investigated the effect of chitosan coating with grape peel extracts (CH + GPE) on the physiochemical properties, protein and lipid oxidation, microstructure, and bacterial community diversity of beef during freeze-thaw (F-T) cycles. The results indicated that the CH + GPE groups had lower pH values, total aerobic count, total volatile base nitrogen, and thiobarbituric acid reactive substance values and better protection against color, water holding capacity, and sensory quality after five F-T cycles. The CH + GPE coating effectively inhibited beef microstructure destruction during the F-T cycles. High-throughput sequencing analysis revealed that the CH + GPE coating contributed to a decline in the bacterial diversity of beef and inhibited the growth of pathogenic bacteria. Interestingly, the CH + GPE coating affected the correlation between quality parameters and bacteria in beef. Consequently, the CH + GPE coating can be used as a novel packaging for preventing the loss of frozen meat quality due to temperature fluctuations.

Composite films of sodium alginate and konjac glucomannan incorporated with tea polyphenols for food preservation.

At present, food waste has become a serious issue and the use of petroleum-based food packaging films has resulted in a series of potential hazards. Therefore, more attention has been focused on the development of new food packaging materials. The polysaccharide-based composite film loaded with active substances considered to be an excellent preservative material. A novel packaging film based on sodium alginate and konjac glucomannan (SA-KGM) blended with tea polyphenols (TP) was prepared in the present study. The excellent microstructure of films was shown by atomic force microscopy (AFM). It was indicated by FTIR spectra that the components could interact with each other through hydrogen bonds, which was also confirmed by molecular docking simulation. Meanwhile, the mechanical properties, barrier property, oxidation property, antibacterial activity, and stability of the structure of the TP-SA-KGM film were significantly improved. The AFM images and results of molecular docking simulation indicated that TP could affect the cell wall of bacteria by acting with peptidoglycan. Finally, the film showed excellent preservation effects in both beef and apples, which suggested that TP-SA-KGM film could be a novel bioactive packaging material with wide application potential in food preservation.

Effects of cellulose nanofibrils treatment on antioxidant properties and aroma of fresh-cut apples.

Horticultural products tend to deteriorate during postharvest storage and processing. In this study, cellulose nanofibers (CNFs) were prepared from wood to investigate the effects of CNF treatment on the storage quality, aroma composition, and antioxidant system of fresh-cut apple (Malus domestica) wedges. Compared with control treatment, CNF coating treatment significantly improved the appearance of apple wedges; reduced the decay rate of apple wedges; and delayed the decline in weight loss, firmness, and titratable acid during storage. Gas chromatography-mass spectrometry showed that CNF treatment could maintain the aroma components of apple wedges (stored for 4 days). Further investigations showed that CNF treatment increased the antioxidant system level and decreased reactive oxygen species content and membrane lipid peroxidation level of apple wedges. Overall, this study showed that CNF coating could effectively maintain the quality of fresh-cut apples during cold storage.

Recent progress in pectin extraction and their applications in developing films and coatings for sustainable food packaging: A review.

Perishable foods like fruits and vegetables, meat, fish, and dairy products have short shelf-life that causes significant postharvest losses, which poses a major challenge for food supply chains. Biopolymers have been extensively studied as sustainable alternatives to synthetic plastics, and pectin is one such biopolymer that has been used for packaging and preservation of foods. Pectin is obtained from abundantly available low-cost sources such as agricultural or food processing wastes and by products. This review is a complete account of pectin extraction from agro-wastes, development of pectin-based composite films and coatings, their characterizations, and their applications in food packaging and preservation. Compared to conventional chemical extraction, supercritical water, ultrasound, and microwave assisted extractions are a few examples of modern and more efficient pectin extraction processes that generate almost no hazardous effluents, and thus, such extraction techniques are more environment friendly. Pectin-based films and coatings can be functionalized with natural active agents such as essential oils and other phytochemicals to improve their moisture barrier, antimicrobial and antioxidant properties. Application of pectin-based active films and coatings effectively improved shelf-life of fresh cut-fruits, vegetables, meat, fish, poultry, milk, and other food perishable products.

Application of chickpea-based edible coating with chickpea husk polyphenols on the preservation of sunflower seeds.

The objective of this study was to evaluate the protective effect of a chickpea-based edible coating with the addition of polyphenols on the chemical, microbiological, and sensory quality of roasted sunflower seeds throughout storage. Four different samples were prepared: roasted sunflower seeds (control sample, SF-C), roasted sunflower seeds with BHT (SF-BHT), roasted sunflower seeds with chickpea-based coating (SF-CCs), and roasted sunflower seeds with chickpea-based coating with chickpea polyphenolic extract (SF-CCPE). The samples were stored for 60 days at room temperature, and their chemical, microbiological, and sensory parameters were analyzed. The acceptability of fresh samples was also studied. The use of chickpea-based coatings retarded the lipid oxidation process efficiently, but the inclusion of chickpea polyphenols in the coating enhanced the protective effect. At 60th day of storage, no statistically significant differences were found between SF-CCPE and SF-BHT in relation to peroxides and conjugated dienes values, saturated/unsaturated ratio, and hexanal content. Linoleic acid content was reduced significantly more in SF-CCs than SF-CCPE. The addition of chickpea coating with chickpea antioxidants did not modify the flavor of the sunflower seeds and was the most accepted treatment by the consumer. The formation of undesirable flavors (cardboard and oxidized) was less in SF-CC, SF-CCPE, and SF-BHT without finding significant differences between these treatments. None of the samples presented microbiological contamination or an increase in bacteria, yeast, and molds during storage. The chickpea-based coating was able to retard lipid oxidation in roasted sunflower seeds, proving to be a good alternative as a natural method to preserve foods with high lipid content. PRACTICAL APPLICATION: Discarded chickpeas and chickpea husks constitute byproducts from the chickpea industry. The grain husks are currently discarded or marketed at a very low cost, constituting a novel residue with antioxidant properties. Considering the growing interest in sustainability and the circular economy, this investigation proposes the utilization of nutritional materials to prepare edible coatings. The chickpea-based coatings loaded with polyphenol extract (obtained from the husk of chickpea) demonstrated to have a protective effect against lipid oxidation process in sunflower seeds, which represent a good alternative to be used for the food industry to increase the shelf life of lipid foods.

Phytochemicals-based edible coating for photodynamic preservation of fresh-cut apples.

Nature-derived chemicals have recently gained increased attention to settle down the challenges in the food industry. Quercetin has long been used as a natural medicine but its photoactivity has been neglected. In this work, by combining photodynamic bacteria inactivation (PDI) with an edible coating (Pectin/Quercetin) derived from FDA-approved chemicals, extend shelf-life and protected commercial quality of fresh-cut apples were achieved. Firstly, the potential photoactivated antibacterial performance of Quercetin (a natural plant flavonoid) was clarified with the treatment of a simulated sunlight lamp, realizing antibacterial efficacy of 100 % towards S. aureus (50 min) and L. monocytogenes (80 min) with light treatment. To develop safe and effective preservation of fresh-cut apples, Pectin/Quercetin edible coatings with 100 µmol/L quercetin were adopted. The results showed that the prepared edible coatings form a protective barrier over the surface of apples, effectively resisting bacterial infection and extending shelf life to 10 days while maintaining good commercial quality (including preferable color, keeping 100 % hardness, 80 % sugar content and 17.3 % weightlessness rate). Therefore, the prepared light-driven Pectin/Quercetin in this work has the potential to develop as fresh-cut fruit preservation technology.

Green nanotechnology for the development of nanoparticles based on alginate associated with essential and vegetable oils for application in fruits and seeds protection.

Aiming to highlight the valorization of the natural products and the green synthesis processes, this work describes the development of a nanoscale system based on the use of alginate to encapsulate a blend of oils (vegetable and essential oils), not previously reported, with antibacterial and antioxidant actions. The study shows the influence of the polymer and surfactant concentrations on the physicochemical properties of the nanoparticles. The formulations were characterized by DLS, zeta potential, efficiency of encapsulation and stability. In addition, the antioxidant and antimicrobial properties of the systems were evaluated using the DPPH method and disk diffusion assays, respectively. The shelf life was studied by coating fruits and seeds. The results showed that the nanostructured system was stable, the efficiency of encapsulation was high and the nanoparticles size range was about 200-400 nm. The coating of fruits and seeds showed that the system was capable of inhibiting the growth of microorganisms and delaying the fruit maturation, indicating its potential for prolonging the shelf-life of fresh food.

Microbiological stability and sensorial valorization of thyme and oregano essential oils alone or combined with ethanolic pomegranate extracts in wine marinated pork meat.

In the present study, wine-based marinades containing ethanolic extract from pomegranate (Punica granatum L.), alone or in combination with two Essential Oils (Thyme & Oregano), were used for pork fillets marination and their antimicrobial activity, as well as their sensorial impact were evaluated. Likewise, the marinades exhibited promising results concerning their recorded antimicrobial activity versus Enterobacteriaceae, Total Mesophilic Bacteria, Yeasts/molds, Staphylococcus spp., Pseudomonas spp. & Lactic Acid Bacteria (LAB). The outcome demonstrated that pork fillets marinated with wine containing ethanolic extract of pomegranate and Oregano Essential Oil were more resistant to spoilage compared to all other samples; thus, their shelf-life was significantly extended (4 days in some cases). Triterpenes (maslinic, oleanolic and betulinic acid), monoterpenes (p-cymene, carvacrol, thymol, limonene), organic acids (citric & malic acid) and phenols, were the main constituents found in the plant extract, the wine and Essential Oils applied, as determined through LC-QTOF/MS and HPLC analysis. Additionally, the sensorial properties (color, tenderness, flavor and juiciness) of the marinated meat samples were not negatively influenced. Consequently, marinades of this type could be used as natural preservatives in meat products, with satisfying antimicrobial and organoleptic results.

Preparation and characterization of antioxidant and pH-sensitive films based on arrowhead (Sagittaria sagittifolia) starch, κ-carrageenan and black chokeberry (Aronia melanocarpa) extract for monitoring spoilage of chicken wings.

In this study, we firstly developed an antioxidant and pH-sensitive film based on arrowhead starch (AS), κ-carrageenan (KC) and black chokeberry extract (BCE) and its physical and structural properties were investigated. We found BCE showed different colors in different pH solutions and incorporation with KC and BCE could significantly decrease light transmittance, increase thickness, elongation at break and pH-sensitive property of AS film. The results of structural property assay indicated that there were some intermolecular interactions between BCE and AS/KC in AS-KC-BCE films. Secondly, we investigated the rheological property of AS, AS-KC and AS-KC-BCE suspensions and found the suspensions showed an obvious shear-thinning behavior with high apparent viscosity. Finally, the functional properties of AS-KC-BCE films were investigated and AS-KC-BCE films showed strong scavenging activity on DPPH free radical and presented visible colour changes in response to the changes of the chicken wing qualities. The results suggest that AS-KC-BCE films can be used in active and intelligent packaging of food industry.

Experimental investigation of different-shaped microwave-heated potatoes: thermal and quality characteristics analysis for food preservation.

Food materials are consumed for nutritional purposes in the form of fruits, vegetables, plants, and meat. These contain proteins, carbohydrates, and other useful nutritional compounds and these processed foods are a rich source of nutrition. The demand and supply of hygienic food for a particular population is possible only by food preservation. It can be done by various methods such as drying, freezing, chilling, chemical preservation, and pasteurization. Drying is a method of food preservation and it can be done by solar drying, microwave heating, vacuum drying, and some other methods. Microwave heating is a fast-drying method. It utilizes electrical energy to generate heat energy. The domestic microwave oven is not harmful but a commercial-level oven may be little bit harmful, when operated on high frequency. Potato is used as a sample material with different shapes such as slab, cylindrical, and spherical. The microwave oven has been operated at four different microwave powers such as 100 W, 300 W, 600 W, and 800 W. Slab-shaped (30 °C), cylindrical-shaped (31.5 °C), and spherical-shaped (30.5 °C) food materials achieved maximum temperatures of 83.9 °C, 110.6 °C, and 146.1 °C respectively. The temperature variations and drying characteristics of the food samples have been monitored. An oven has achieved maximum drying efficiency of 25.65% with a slab-shaped sample. For the detection of the cracks and chemical compositions in the food samples, SEM with EDS analysis has been performed. Economic analysis of microwave oven has also been done and payback period has been found as 3.27 years.

Effect of the addition of chokeberry leaf extract on the physicochemical and sensory properties of burgers from dark cutting veal.

The occurrence of the DFD defect shortens microbiological stability and reduces consumer acceptance of meat. The effect of a chokeberry leaf extract (ChLE) addition at concentrations of 0.01 %, 0.05 % and 0.1 % on the sensory and physicochemical properties of burgers prepared from DFD meat during refrigerated storage under vacuum for 10 days was assessed. The pH, water activity, texture, colour, degree of lipid oxidation, and content of α-tocopherol were measured. The extract at concentrations of 0.05 % and 0.1 % significantly influenced lower levels of lipid oxidation and higher content of α-tocopherol on each tested period. Moreover, these concentrations had a beneficial effect on the instrumental and sensory evaluation of texture parameters and on overall quality. It was concluded that the addition of 0.1 % extract was the most beneficial over the entire 10-day storage period. In summary, use of ChLE may reduce the loss of raw meat caused by DFD defect.

Influence of the combination of cinnamon essential oil nanoemulsions and epsilon-polylysine on microbial community and quality of pork during refrigerated period and radio frequency cooking.

Pork preservation and cooking are common processes in food production. This study analyzed the influence of cinnamon essential oil nanoemulsions (CEON), ε-polylysine (ε-PL) and CEON/ε-PL on microbial community and quality of pork during refrigerated storage and radio frequency (RF) cooking. Results showed that a stable CEON was prepared with soybean lecithin (oil: lecithin = 1:1 w/w). CEON and ε-PL inhibited the growth of total bacteria counts (TBC) of raw pork, and caused Salmonella reduction at refrigerated storage of 12 d. Photobacterium and Pseudomonas were dominant spoilage bacteria of raw pork during refrigerated period. The 0.25 % CEON and 0.125 % CEON + 0.25 % ε-PL had good antimicrobial effects against Photobacterium while 0.5 % ε-PL had a small effect. Pork treated by CEON and CEON/ε-PL had better freshness than control and ε-PL treated samples. RF cooking lowered cooking time compared to water bath cooking at 80 °C and a similar quality of cooked pork was observed. CEON/ε-PL promoted Salmonella and TBC inactivation during RF cooking. TVB-N content, pH, cooking loss and appearance of RF cooked pork were not influenced by the addition of CEON/ε-PL, but the odor was slightly affected. The hardness, springiness and chewiness were enhanced by the addition of CEON/ε-PL. The results revealed that CEON/ε-PL could be used in raw pork preservation and promote bacteria inactivation during RF cooking.

An overview of the natural antimicrobial alternatives for sheep meat preservation.

Sheep meat is consumed and appreciated all over the world for its nutritional value and flavor. However, this meat is very perishable and easily subjected to the action of both spoilage and pathogenic microorganisms. For this reason, in combination with cold storage, effective preservation techniques are required. There is increasing interest in the application of natural antimicrobials, such as essential oils, extracts, spices, and by-products of the food industry. This review analyses the studies on natural antimicrobials in sheep meat and sheep meat products and gathers evidence about the encouraging results achieved on the reduction and/or elimination of spoilage and pathogenic microorganisms. The use of these natural antimicrobial alternatives might open up important perspectives for industrial application, considering that this specific meat is often traded over long distances. In fact, on the basis of scientific literature, natural antimicrobials can be considered a sustainable and affordable alternative to extend the shelf life of sheep meat and guarantee its safety, although many factors need to be further investigated, such as the sensory impact, potential toxicity, and economic aspects. For all these issues, investigated in some of the studies reviewed here, it is fundamental to obtain the antimicrobial effect with the minimum amount of effective substance to avoid sensory modifications, toxic effects, and unbearable costs. This study sets foundations for the possible direction of future studies, which will contribute to identify effective solutions for industrial applications of natural antimicrobials in the sheep meat industry.