Current trends in natural preservatives for fresh sausage products

Effect of cinnamaldehyde-nanoemulsion and nanostructured lipid carriers on physicochemical attributes of reduced-nitrite sausages

This study aimed to produce cinnamaldehyde (CA)-loaded nanostructured lipid carriers (NLC) and nanoemulsion (NE) to replace nitrite in sausage. The NLC and NE droplet sizes were 132 and 116 nm with encapsulation efficiency of 98 and 96 %, respectively. In in vitro antimicrobial assessment, the free CA and NE showed higher microbial activity against S. aureus and E. coli than NLC. Meanwhile, NE showed a faster release profile for CA than NLC. Among the samples, NE and NE + nitrite indicated the lowest peroxide value (3.7 ± 0.1), TVBN amount (8.6 ± 0.2), acidity (0.3 ± 0.02), microbial quality (against E. coli, C. perfringens, lactic acid bacteria, psychrophilic bacteria, total mold and yeast, and total viable counts), and sensory attribute, while the NE + nitrite sample exhibited better color properties and higher oxymyoglobin content (5-10 % higher). Therefore, NE + nitrite can be the best choice due to supporting the different quality parameters of sausage.

Exploring the antioxidant potential of nekemias species extracts on edible oils: In vitro assessment and lipid oxidation inhibition

Synthetic antioxidants have long been used to protect edible oils from oxidation. However, concerns about their potential health risks and environmental impact have led to a growing interest in natural antioxidants. In this study, we explore the antioxidant properties of extracts from four Nekemias plant species: Nekemias grossedentata (AGR), Nekemias megalophylla (AME), Nekemias chaffanjonii (ACH), and Nekemias cantoniensis (ACA) by obtaining the values for different tests. We investigate their bioactive compound content and evaluate their antioxidant capabilities on six edible oils categorized into three lipid systems based on their fatty acid compositions: oleic acid, linoleic acid, and linolenic acid. Our findings demonstrate that AGR and AME extracts, rich in bioactive compounds, exhibit strong antioxidant activities in vitro, effectively inhibiting lipid oxidation, especially in oleic acid-rich oils like camellia oil. The antioxidant effects of these extracts are comparable to synthetic antioxidants such as TBHQ and superior to natural antioxidant Tea Polyphenols (TP). While the extracts also show antioxidant potential in linoleic and linolenic acid systems, the stability of their effects in these oils is lower than in oleic acid system. These results suggest that Nekemias species extracts have the potential to serve as natural additives for extending the shelf life of edible oils, contributing to the exploration of natural antioxidants.

A comparative study between the performance of thymol-nanoemulsion and thymol-loaded nanostructured lipid carriers on the textural, microbial, and sensory characteristics of sausage

The objective of this research was to compare the function of thymol-loaded nanostructured lipid carriers (NLC) and a thymol-nanoemulsion (NE) with nitrite (120 mg/kg) on quality parameters of sausage. The droplet size of the NLC and NE was 140 and 86.39 nm with encapsulation efficiency of 97 and 94%, respectively. The results on sausage showed that all samples containing NLC and NE exhibited the lowest increase in peroxide value, total volatile base-nitrogen, and TBA with the highest inhibitory effect on the growth of E. coli, C. perfringens, lactic acid bacteria, psychrophilic bacteria, mold and yeast, and total viable counts as well as good texture and sensory attributes with the best results in the NLC + nitrite and NE + nitrite samples. The L* and a* values were relatively higher in the samples treated with nitrite, NLC + nitrite, and NE + nitrite after 4-week storage. This increase in redness was associated with the maintenance of oxymyoglobin levels and a decrease in metmyoglobin production. The results of this study indicated that the combined use of NLC/NE (particularly NE) with 60 mg/kg nitrite significantly improved the oxidative and color stability, and delayed the spoilage and off-flavor in sausage.

Stevia rebaudiana leaves fermented by Lactobacillus plantarum exhibit resistance to microorganisms and cancer cell lines in vitro: A potential sausage preservative

Natural preservatives are causing a rethinking of current preservation means. As a sweetener resource, exploitation of Stevia rebaudiana leaves (SRLs) is still restricted due to human conventional cognition. Herein, Lactobacillus plantarum fermented SRLs containing diverse free secondary metabolites derived from microbial deglycosylation and bioenzymatic decomposition were investigated. The apparent resistance to typical foodborne bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomoas aeruginosa, Bacillus amyloliquefaciens) by fermented SRLs and their extracts were validated. The metabolite diversity and in-depth organic solvent extraction gave the possibilities for better antimicrobial actions, anti-HepG2/SGC-7901 cells in vitro in contrast with aqueous extract of unfermented SRLs. Crucially, compound identification and attribution revealed that fermentation products may be maximally contributing to antimicrobial and antitumor mechanisms rather than intrinsic plant and/or microbial components. Additionally, pork sausage models with 15 g/kg ethyl acetate extract as a preservative candidate presented preferred storage characteristics (21 days and 37 °C) compared to those without ethyl acetate extract, e.g. the minimal total plate count (3.86 ± 0.27 log CFU/g), peroxsignide value (8.02 ± 0.92 meq/kg), and acid value (2.01 ± 0.04 (KOH)/(mg/g)).

Kakadu plum (Terminalia ferdinandiana) bioactivity against spoilage microorganisms and oxidative reactions in refrigerated raw beef patties under modified atmosphere packaging

Raw beef patties were treated with either 450 ppm of Sodium metabisulphite (SMB), or Kakadu plum powder (KPP) (0.2%, 0.4%, 0.6%, 0.8%) or no additive (negative control) and stored under Modified Atmosphere Packaging at 4 ± 1 °C for 20 days. Lipid oxidation, microbial growth rate, pH, instrumental color, and surface myoglobin were studied. Total phenolic compounds (TPC) and vitamin C of the KPP were also measured. The TPC was 13.9 g GAE/ 100 g dry weight (DW) and for vitamin C, the L-AA (l-ascorbic acid) and DHAA (dehydroascorbic acid) were 12.05 g/100 g and 0.5 g/ 100 g DW, respectively. The experimental results indicated that lipid oxidation was significantly delayed throughout the storage period for KPP-treated samples compared to both the negative control and SMB-treated samples. KPP at levels of 0.2% and 0.4% in the raw beef patties were efficient in slowing down the microbial growth rate compared to the negative control; however, SMB had a higher antimicrobial activity. The pH, the redness as well as metmyoglobin formation in the raw beef patties were reduced by the inclusion of the KPP in treated samples. A correlation (r = -0.66) was noted between KPP treatments and lipid oxidation, but there was no correlation (r = -0.006) between KPP treatment and microbial growth. This study demonstrates that KPP could be used as natural preservative for shelf-life extension of raw beef patties.

Edible Coatings and Future Trends in Active Food Packaging-Fruits' and Traditional Sausages' Shelf Life Increasing

The global food production industry faces environmental concerns exacerbated by substantial food waste. European countries are striving to reduce food waste towards a circular bioeconomy and sustainable development. To address environmental issues and reduce plastic waste, researchers are developing sustainable active packaging systems, including edible packaging made from industry residues. These innovations aim to increase food safety and quality, extend shelf life, and reduce plastic and food waste. Particularly important in the context of the growing demand for fresh and minimally processed fruits, edible coatings have emerged as a potential solution that offers numerous advantages in maintaining fruit quality. In addition to fruit, edible coatings have also been investigated for animal-based foods to meet the demand for high-quality, chemical-free food and extended shelf life. These products globally consumed can be susceptible to the growth of harmful microorganisms and spoilage. One of the main advantages of using edible coatings is their ability to preserve meat quality and freshness by reducing undesirable physicochemical changes, such as color, texture, and moisture loss. Furthermore, edible coatings also contribute to the development of a circular bioeconomy, promoting sustainability in the food industry. This paper reviews the antimicrobial edible coatings investigated in recent years in minimally processed fruits and traditional sausages. It also approaches bionanocomposites as a recently emerged technology with potential application in food quality and safety.

The correlation among residual nitrites, biogenic amines, N-nitrosamine formation, and degradation occurrence of punicalagin α/β, rosmarinic acid, carnosol, and carnosic acid in extract-treated sausage during storage

The aim of this study was to investigate the relation between residual α- and β-punicalagin in Punica granatum L.; PPE and rosmarinic acid, carnosol, and carnosic acid in Salvia eremophila (SE) with residual nitrites, biogenic amines (cadaverine, putrescine, and histamine), N-nitrosodimethylamine (NDMA), microbial counts, lipid oxidation indices, and color values in extract-treated sausage over 14 days of storage. Sausage containing SE + nitrite 60 ppm (SSN) showed minimum levels of the residual nitrites (13.14 mg/kg), NDMA (0.74 ± 0.05 μg/kg), and biogenic amine (histamine, 1.8 mg/kg; cadaverine, 3.7 mg/kg; and putrescine, 4.3 mg/kg) due to retarded degradation rate of 285.84-216.44 mg/kg; rosmarinic acid, 41.62-33.16 mg/kg; carnosol, and 88.70-76.73 mg/kg; carnosic acid over storage time. The first-order kinetic model fitted well for the degradation of rosmarinic acid and carnosol acid in SSN sample. TBA value remained below the threshold limit (0.32 mg kg-1) through 14 days for SSN. Second-order and zero-order reaction models had the best agreement with sausages' PV and TBA values, respectively. After 2 weeks of storage, E. coli and Cl. perfringens counts in the SN120 (sausage containing 120 ppm nitrite) and SSN were significantly lower than the other samples (p < .05), with the values 2.1 and 1.5 log cfu/g for SN120 and 2.2 and 1.6 log cfu/g for SSN formulation. Conversely, oxidation indices, residual nitrites, NDMA, and biogenic amine increased in sausage samples containing PPE extracts (SPN) owing to total degradation of α- and β-punicalagin during storage. The results indicated that SE can be used as potential co-preservative by reducing the levels of required nitrite in food industry.

Biologically Active Compounds from Probiotic Microorganisms and Plant Extracts Used as Biopreservatives

Ensuring the microbiological safety of food products is a pressing global concern. With the increasing resistance of microorganisms to chemical agents and the declining effectiveness of synthetic preservatives, there is a growing need for alternative sources of natural, bioactive compounds with antimicrobial activity. The incorporation of probiotics and plant extracts into food formulations not only enriches foodstuffs with microorganisms and phytochemicals with biologically active compounds, but also provides a means for product preservation. The current review considers the importance of the process of biological preservation for providing safe foods with high biological value, natural origin and composition, and prolonged shelf life, thereby improving consumers' quality of life. To accomplish this goal, this review presents a series of examples showcasing natural preservatives, including beneficial bacteria, yeasts, and their metabolites, as well as phenolic compounds, terpenoids, and alkaloids from plant extracts. By summarizing numerous studies, identifying research challenges and regulatory barriers for their wider use, and outlining future directions for investigation, this article makes an original contribution to the field of biopreservation.

Technological innovations enhance postharvest fresh food resilience from a supply chain perspective

Fresh food is rich in nutrients but is usually seasonal, perishable, and challenging to store without degradation of quality. The inherent limitations of various preservation technologies can result in losses in all stages of the supply chain. As consumers of fresh foods have become more health-conscious, new technologies for intelligent, energy-efficient, and nondestructive preservation and processing have emerged as a research priority in recent years. This review aims to summarize the quality change characteristics of postharvest fruits, vegetables, meats, and aquatic products. It critically analyzes research progress and applications of various emerging technologies, which include: the application of high-voltage electric field, magnetic field, electromagnetic field, plasma, electrolytic water, nanotechnology, modified atmosphere packaging, and composite bio-coated film preservation technologies. An evaluation is presented of the benefits and drawbacks of these technologies, as well as future development trends. Moreover, this review provides guidance for design of the food supply chain to take advantage of various technologies used to process food, reduce losses and waste of fresh food, and this improve the overall resilience of the supply chain.

Effects of blackberry polysaccharide on the quality improvement of boiled chicken breast

Blackberry polysaccharide was isolated from blackberry powder with 70% ethanol. The crude polysaccharide was composed of 95.44% glucose, 2.01% arabinose, 1.81% galactose and 0.74% glucuronic acid. Chicken breast meat was only marinated with different concentrations of the isolated blackberry polysaccharide (1 g/kg, 3 g/kg) for 24 h at a ratio of material to liquid of 1:3, and boiled at 80℃ for 1 h. The differences in texture, water distribution and volatile flavor components among different groups （adding 0,1,3 g/kg blackberry polysaccharide) were investigated. The results showed that the addition of blackberry polysaccharide could significantly improve the hardness of chicken breast, the transformation of free water to bound water, the overall flavor characteristics of the control group and the addition of different concentrations of blackberry polysaccharide were significantly different, and the concentration of volatile flavor substances in boiled chicken breast was reduced.

Assessment of Bioactive Phytochemicals and Utilization of Rosa canina Fruit Extract as a Novel Natural Antioxidant for Mayonnaise

The oxidation of food emulsions causes rancidity, which reduces their shelf life. To prevent rancidity, synthetic antioxidants are widely used in the food industry. However, due to their potential health risks, researchers are exploring natural alternatives. This study aimed to investigate whether Rosa canina fruit extract (RCFE) could be used as a natural antioxidant to extend the shelf life of mayonnaise. Mayonnaise containing varying concentrations of RCFE [0.125% (T1), 0.25% (T2), 0.50% (T3), 0.75% (T4)] was compared to a mayonnaise control sample (C1) and a mayonnaise sample containing 0.02% BHT (C2) for 60 days of storage at 4 °C. RCFE was found to have high levels of total phenols content (52.06 ± 1.14 mg GAE g^-1), total flavonoids content (26.31 ± 1.03 mg QE g^-1), and free radical scavenging activity. The GC-MS analysis of RCFE revealed 39 different peaks, whereas the HPLC analysis showed the presence of 13 polyphenolic compounds in RCFE. The pH values of T2, T3, and T4 mayonnaise samples substantially declined as storage progressed; however, the reduction was less than that of C1 and C2. After 60 days, mayonnaise samples T2, T3, and T4 had greatly reduced peroxide and free fatty acid levels compared to C1 and C2. The mayonnaise enriched with RCFE (T3 and T4) had the most potent antioxidative ability and the lowest value of lipid hydroperoxides (peroxide value, POV) and the lowest value of thiobarbituric-acid-reactive substances (TBARS). The sensory evaluation revealed that the T3 sample exhibited the highest overall acceptability. In conclusion, this study recommends that RCFE could be used as a natural preservative to enhance the shelf life of functional foods.

Investigation on the Contents of Nε-carboxymethyllysine, Nε-carboxyethyllysine, and N-nitrosamines in Commercial Sausages on the Chinese Market

Sausages are among the most popular meat products worldwide. However, some harmful products, such as advanced glycation end-products (AGEs) and N-nitrosamines (NAs), can be formed simultaneously during sausage processing. In this study, the contents of AGEs, NAs, α-dicarbonyls and the proximate composition were investigated in two kinds of commercial sausages (fermented sausages and cooked sausages) in the Chinese market. The correlations among them were further analyzed. The results showed that the fermented and cooked sausages had different in protein/fat contents and pH/thiobarbituric acid reactive substance values due to their different processing technologies and added ingredients. The N^ε-carboxymethyllysine (CML) and N^ε-carboxyethyllysine (CEL) concentrations varied from 3.67 to 46.11 mg/kg and from 5.89 to 52.32 mg/kg, respectively, and the NAs concentrations ranged from 1.35 to 15.88 µg/kg. The contents of some hazardous compounds, such as CML, N-nitrosodimethylamine, and N-nitrosopiperidine, were observed to be higher in the fermented sausages than in the cooked sausages. Moreover, levels of NAs in some sausage samples exceeded the limit of 10 µg/kg issued by the United States Department of Agriculture, suggesting that particular attention should be paid to mitigating NAs, especially in fermented sausages. The correlation analysis suggested that the levels of AGEs and NAs were not significantly correlated in both kinds of sausages.

Incorporating dietary fiber from fruit and vegetable waste in meat products: a systematic approach for sustainable meat processing and improving the functional, nutritional and health attributes

Background

Every year, the food business produces a sizeable amount of waste, including the portions of fruits and vegetables that are inedible, and those that have reached a stage where they are no longer suitable for human consumption. These by-products comprise of components such as natural antioxidants (polyphenols, carotenoid etc.), dietary fiber, and other trace elements, which can provide functionality to food. Due to changing lifestyles, there is an increased demand for ready-to-eat products like sausages, salami, and meat patties. In this line, meat products like buffalo meat sausages and patties are also gaining the interest of consumers because of their rich taste. Meat, however, has a high percentage of fat and is totally deprived of dietary fiber, which poses severe health problems like cardiovascular (CV) and gastrointestinal diseases. The health-conscious consumer is becoming increasingly aware of the importance of balancing flavor and nutrition. Therefore, to overcome this problem, several fruit and vegetable wastes from their respective industries can be successfully incorporated into meat products that provide dietary fiber and play the role of natural antioxidants; this will slow down lipid oxidation and increase the shelf-life of meat products.

Methodology

Extensive literature searches have been performed using various scientific search engines. We collected relevant and informative data from subject-specific and recent literature on sustainable food processing of wasted food products. We also looked into the various applications of waste fruit and vegetable products, including cereals, when they are incorporated into meat and meat products. All relevant searches meeting the criteria were included in this review, and exclusion criteria were also set.

Results

The pomace and peels of fruits like grapes, pomegranates, cauliflower, sweet lime, and other citrus are some of the most commonly used fruit and vegetable by-products. These vegetable by-products help inhibit oxidation (of both lipids and proteins) and the growth of pathogenic and spoilage bacteria, all without altering the consumer's acceptability of the product on a sensory level. When included in meat products, these by-products have the potential to improve the overall product quality and lengthen its shelf-life under certain circumstances.

Conclusion

Cost-effective and easily accessible by-products from the fruit and vegetable processing industries can be used in meat products to enhance their quality features (physicochemical, microbial, sensory, and textural aspects) and health benefits. Additionally, this will provides environmental food sustainability by lowering waste disposal and improving the food's functional efficacy.

In Vitro and In Silico Evaluation of the Antimicrobial and Antioxidant Potential of Thymus pulegioides Essential Oil

The study was designed to analyze and evaluate the antioxidant and antibacterial properties of the essential oils of Thymus pulegioides L. grown in Western Romania. Thymus pulegioides L. essential oil (TPEO) was extracted by steam distillation (0.71% v/w) using a Craveiro-type apparatus. GC-MS investigation of the TPEO identified 39 different compounds, representing 98.46% of total oil. Findings revealed that thymol (22.89%) is the main compound of TPEO, followed by para-cymene (14.57%), thymol methyl ether (11.19%), isothymol methyl ether (10.45%), and beta-bisabolene (9.53%). The oil exhibits good antibacterial effects; C. parapsilosis, C. albicans, S. pyogenes, and S. aureus were the most sensitive strains. The antioxidant activity of TPEO was evaluated by peroxide and thiobarbituric acid value, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium] (ABTS) radical scavenging assay, and beta-carotene/linoleic acid bleaching testing. The antioxidative data recorded reveal, for the first time, that TPEO inhibits primary and secondary oxidation products, in some particular conditions, better than butylated hydroxyanisole (BHA) with significant statistical difference (p < 0.05). Moreover, TPEO antioxidant capabilities in DPPH and ABTS assays outperformed alpha-tocopherol (p < 0.001) and delta-tocopherol (p < 0.001). Molecular docking analysis revealed that one potential target correlated with the TPEO antimicrobial activity was d-alanine-d-alanine ligase (DDl). The best scoring ligand, linalyl anthranilate, shared highly similar binding patterns with the DDl native inhibitor. Furthermore, molecular docking analysis also showed that the main constituents of TPEO are good candidates for xanthine oxidase and lipoxygenase inhibition, making the essential oil a valuable source for protein-targeted antioxidant compounds. Consequently, TPEO may represent a new potential source of antioxidant and antibacterial agents with applicability in the food and pharmaceutic industries.

Shikonin Functionalized Packaging Film for Monitoring the Freshness of Shrimp

A shikonin embedded smart and active food packaging film was produced using a binary mixture of gelatin and cellulose nanofiber (CNF). Shikonin is an alcohol-soluble natural pigment extracted from Lithospermum erythrorhizon root. The fabricated film showed good pH-responsive color changes and volatile gas sensing properties. Moreover, the film exhibited excellent antioxidant and antibacterial activity against foodborne pathogens. The shikonin incorporated gelatin/CNF-based film showed excellent UV-light barrier properties (>95%) and high tensile strength (>80 MPa), which is useful for food packaging. The hydrodynamic properties of the film were also slightly changed in the presence of shikonin, but the thermal stability and water vapor permeability remained unaffected. Thus, the inclusion of shikonin in the gelatin/CNF-based film improves not only the physical properties but also the functional properties. The film’s color indicator properties also clearly show shrimp’s freshness and spoilage during storage for 48 h. The shikonin-based functional film is expected to be a promising tool for multi-purpose smart and active food packaging applications.

Active edible films with plant extracts: a updated review of their types, preparations, reinforcing properties, and applications in muscle foods packaging and preservation

Currently, edible films have been increasingly explored to solve muscle food spoilage during storage, especially through the incorporation of plant extracts to develop edible packaging materials. Natural polymers matrices with plant extracts are befitting for fabricating edible films by casting methods. In the films system, the structure and physicochemical properties were strengthened via chemical interactions between active molecules in plant extracts and the reactive groups in the polymer chain. The antibacterial and antioxidant properties were dramatically reinforced through both physical and chemical actions of the plant extracts. Additionally, edible films imbedded with color-rich plant extracts could be considered as potential sensitive indicators to monitor the spoilage degree of muscle foods in response to change in gas or temperature. Furthermore, these films could increase sensory acceptability, improve quality and prolong the shelf life of muscle foods. In this article, the types, preparation methods and reinforcing properties of the edible films with plant extracts were discussed. Also, the applications of these films were summarized on quality maintenance and shelf-life extension and intelligent monitoring in muscle foods. Finally, a novel technology for film preparation achieving high-stability and sustained release of active compounds will become an underlying trend for application in muscle food packaging.

Effects of Pleurotus ostreatus on Physicochemical Properties and Residual Nitrite of the Pork Sausage

In this work, a novel sausage incorporated with the Pleurotus ostreatus (PO) puree was successfully developed to reduce the residual nitrite and lipid oxidation during refrigerated storage (4 ± 1 °C) for 20 days. Five recipes with the supplement proportion of 0 wt.%, 10 wt.%, 20 wt.%, 30 wt.%, and 40 wt.% PO were produced and their physicochemical properties, nitrite residue, and sensory characteristics were measured. The results show that the content of moisture and all the essential amino acids (especially lysine and leucine) and the non-essential amino acids (especially aspartic and glutamic), lightness, springiness, and water holding capacity of the sausages were increased. However, the content of protein, fat, ash, pH, redness, hardness, gumminess, and chewiness of the sausages was decreased. For the sensory evaluation, the sausage with 20 wt.% PO had better sensory performance including flavor, aroma, and acceptability compared with other experimental groups and the control group. Moreover, the sausages with PO reduced the residual nitrite and inhibited lipid oxidation during storage. All of these results indicate that adding PO puree into pork sausage is a realizable and effective way to obtain nutritional and healthy pork sausages.

UHPLC-Q-Orbitrap-based lipidomics reveals molecular mechanism of lipid changes during preservatives treatment of Hengshan goat meat sausages

As preservative are extensively applied to prevent the quality degradation of Hengshan goat meat sausages, safety assessment based on lipid and elucidation of dynamic change mechanism is urgently needed. The effect of preservatives on lipidome profiles of sausages was investigated using UHPLC-Q-Orbitrap. Totally, 9 subclasses of 70 characteristic lipids (Cer, DG, LPC, PC, PE, PI, PS, SM, TG) were quantified accurately (LOD with 0.68-2.96 μg kg^-1, LOQ with 2.25-9.79 μg kg^-1, RSD < 3%). The decrease of TG concentration was the most significant, from 1072.43 mg kg^-1 in preservative-free samples to 838.53, 786.41 and 681.35 mg kg^-1 in natamycin, potassium sorbate and sodium diacetate treated samples, respectively. With regard to preservation and nutrition, natamycin was a potential preservative than two other preservatives. Significant lipid variables were primarily associated with glycerophospholipid and sphingolipid metabolism. Integration of both techniques provided a guide for meat industries to control spoilage with innovative strategies.

Natamycin: a natural preservative for food applications-a review

Natamycin is a natural antimicrobial peptide produced by the strains of Streptomyces natalensis. It effectively acts as an antifungal preservative on various food products like yogurt, khoa, sausages, juices, wines, etc. Additionally, it has been used as a bio preservative and is listed as generally recognized as a safe ingredient for various food applications. In this review, natamycin properties, production methods, toxicity, and application as a natural preservative in different foods are emphasized. This review also focuses on optimal condition and process control required in natamycin production. The mode of action and inhibitory effect of natamycin on yeast and molds inhibition and its formulation and dosage to preserve various food products, coating, and hurdle applications are summarized. Understanding the scientific factors in natamycin's production process, its toxicity, and its efficiency as a preservative will open its practical application in various food products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00981-1.

Edible Films on Meat and Meat Products

In 2018, the worldwide consumption of meat was 346.14 million tonnes, and this is expected to increase in the future. As meat consumption increases, the use of packaging materials is expected to increase along with it. Petrochemical packaging materials which are widely used in the meat processing industry, take a long time to regenerate and biodegrade, thus they adversely affect the environment. Therefore, the necessity for the development of eco-friendly packaging materials for meat processing, which are easily degradable and recyclable, came to the fore. The objective of this review is to describe the application of natural compound-derived edible films with their antioxidant and antibacterial activities in meat and meat products. For several decades, polysaccharides (cellulose, starch, pectin, gum, alginate, carrageenan and chitosan), proteins (milk, collagen and isolated soy protein) and lipids (essential oil, waxes, emulsifiers, plasticizers and resins) were studied as basic materials for edible films to reduce plastic packaging. There are still high consumer demands for eco-friendly alternatives to petrochemical-based plastic packaging, and edible films can be used in a variety of ways in meat processing. More efforts to enhance the physiological and functional properties of edible films are needed for commercial application to meat and meat products.

Characterization of Pediococcus acidilactici postbiotic and impact of postbiotic-fortified chitosan coating on the microbial and chemical quality of chicken breast fillets

This study was carried out to characterize antioxidant activity, total phenolic content, and the phenolic and flavonoids profile of postbiotic of Pediococcus acidilactici and to evaluate the effects of postbiotics (10% and 50%) alone and in combination with chitosan coating (1%) on the microbial and chemical quality of chicken breast fillets during storage at 4 °C. Antioxidant activity and total phenolic content of the postbiotics were found to be 1291.02 ± 1.5 mg/L TEAC and 2336.11 ± 2.36 mg/L GAE, respectively. The most abundant phenolic was vanillic acid, followed by t-caffeic, gallic, and caftaric acids. The postbiotic-chitosan (50% + 1%) combination decreased L. monocytogenes and S. Typhimurium counts by 1.5 and 2.1 log₁₀ CFU/g, respectively, compared to the control (P < 0.05). This combination decreased the total viable count (TVC), lactic acid bacteria (LAB), and psychrotrophic bacteria count compared to the control (P < 0.05). No differences were found in thiobarbituric acid (TBA) values among the samples during storage (P > 0.05). Postbiotic treatment did not significantly change the pH values and color properties of the breast fillets (P > 0.05). Postbiotic-chitosan combinations extended the shelf-life by up to 12 days compared to the control. In conclusion, the postbiotic-chitosan combination can be used to preserve and improve the microbial quality of chicken meat products.

Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage

High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10⁻¹¹ g/m s Pa) than commercial chitosans films (from 16.06 × 10⁻¹¹ to 64.30 × 10⁻¹¹ g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24% to 2.38%). A higher increase in hardness (from 22.32 N to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.

Combined effects of Ziziphora clinopodioides essential oil and lysozyme to extend shelf life and control Listeria monocytogenes in Balkan-style fresh sausage

This study was done to evaluate the effects of different concentrations of Ziziphora clinopodioides essential oil (ZCEO) (0, 0.1, and 0.3%) and lysozyme (0 and 400 µg/g) on control of Listeria (L.) monocytogenes and also microbial, chemical, and organoleptic properties of Balkan type fresh sausage under modified atmosphere packaging (MAP) during 13-day storage at refrigerated condition. Results revealed that treated sausages had a slower rate of increase in microbial count than control and sausages containing ZCEO (0.3%) and lysozyme (400 µg/g) possess the lowest microbial count at the end of the storage period. A reduction between 0.90 and 2.05 log CFU/g in L. monocytogenes was recorded for the treated sausage samples in comparison with control samples after 13 days of storage. Based on chemical findings, at the end of the storage, TVB-N value in the control sample gradually increased to 34.30 mg/100 g, whereas TVB-N values of the treated samples with each of the lysozyme and ZCEO alone or in combination were below 25 mg/100 g during the entire storage period. The final TBARS value for the control sample was 0.58 mg malondialdehyde/kg, while the TBARS values for the treated samples remained lower as 0.46 mg malondialdehyde/kg. Regarding sensory attributes, adding ZCEO results in insignificant lower scores in odor and taste than control in the early days of the study (p > .05). It can be argued that ZCEO alone or in combination with lysozyme showed good antimicrobial and antioxidant activities and may have this potential to be used as a preservative in fresh sausage without any significant adverse sensory effects (p > .05).

Use of barley malt pomace in the production of fresh sausage

Abstract The present study aimed to evaluate the effects of barley malt pomace addition on the characteristics of fresh pork sausages over 10 days of storage. Four fresh sausage formulations were elaborated, one with no addition of barley malt pomace (control formulation), and the other three elaborated with 3%, 6%, and 9% of pomace. The sausages were submitted to physicochemical analyses to determine ash, moisture, protein, lipid, carbohydrate, and raw fiber contents, water activity, pH, peroxide indices, and energetic value. Additionally, texture and color technological analysis and sensory analysis were performed. Sausages with 3% of malt pomace presented a protein content of 17.10% on the 10th day of storage, and raw fiber content of 2.00%; while in the control formulation these contents were 16.59% and 0.77%, respectively, with a significant difference (p ≤ 0.05) between samples, representing an increase in product nutritional value. In the hardness analysis, the control formulation had a value of 13.99 N and the formulation with 3% of pomace of 10.11 N, which shows that sausages with the addition of pomace are not as hard. In the sensory analysis, the control formulation showed about 80% acceptability in all attributes, the sausage with 3% of malt pomace had an acceptability index higher than 80% for the attribute 'global acceptance', the sausage with 6% of pomace had an index of approximately 70% and the formulation with 9% showed acceptability index of approximately 64% for the attribute 'global acceptance'. The addition of 3% of malt pomace to the sausage was the best alternative, since it had good acceptance by consumers, and provided an increased nutritional value. Our results show that the use of malt pomace in meat products is a viable alternative that helps to reduce production costs and aids in solving an environmental issue.

The effects of storage and hop extract on aroma and flavour compounds in Balkan-style sausages packed under a CO2-containing anaerobic atmosphere

Changes in the levels of pH, lactic acid, acetic acid, headspace volatile compounds, and spoilage odour intensity during a 35 day refrigerated storage period in two sets of a Balkan-style fresh sausage, a control sausage (CON) and a sausage containing an aqueous hop extract (HOP), packaged under a 20% CO2 and 80% N2 atmosphere were evaluated. Storage resulted in progressive sausage acidification and increased the levels of acetic acid, 1-methylbutanol, ethyl acetate, ethyl hexanoate, and 2-ethylhexanol; all of which are associated with anaerobic microbial metabolism under sugar restricted conditions. Storage decreased the levels of hexanal, heptanal, pentanol, and garlic-derived organosulfur compounds. Hop extract showed oxygen scavenging abilities, and decreased the levels of the volatile compounds derived from lipid auto-oxidation while contributing to the presence of specific terpene compounds. The use of hop extract did not improve the shelf life of sausages packed under anaerobic atmosphere. The spoilage odour appeared in both types of sausages on the 14th day, and it was considered strong from day 21 onwards.

Sulfites in meat: Occurrence, activity, toxicity, regulation, and detection. A comprehensive review

Sulfites are a class of chemical compounds, SO₂ releasers, widely used as additives in food industry, due to their antimicrobial, color stabilizing, antibrowning, and antioxidant properties. As the results of these pleiotropic functions they can be added to a broad range of products including dried fruits and vegetables, seafood, juices, alcoholic and nonalcoholic beverage, and in few meat products. Sulfites ingestion has been correlated with several adverse and toxic reactions, such as hypersensitivity, allergic diseases, vitamin deficiency, and may lead to dysbiotic events of gut and oral microbiota. In many countries, these additives are closely regulated and in meat products the legislation restricts their usage. Several studies have been conducted to investigate the sulfites contents in meat and meat products, and many of them have revealed that some meat preparations represent one of the main sources of SO₂ exposure, especially in adults and young people. This review discusses properties, technological functions, regulation, and health implications of sulfites in meat-based foods, and lays a special emphasis on the chemical mechanisms involved in their interactions with organic and inorganic meat components.

Reduction of sodium additives in cooked sausages: effect on physicochemical, sensory and microbiological characteristics

Several efforts have been made to reduce sodium in meat products due to its demonstrated negative health effects. This study evaluated the effect on physicochemical, sensory and microbiological characteristics of cooked sausages after a simultaneous reduction of salt (2.2% and 1.8%), Na-lactate (2.8% and 1.5%) and sodium tripolyphosphate (STPP) (0.4% and 0.2%). Salt and STPP reduction affected cooking loss, while no significant differences (P > 0.05) were obtained in instrumental and sensory texture for all factors. Discrimination tests showed significant perceived differences between some pairs, however, d' values were below 0.55 in all comparisons, meaning consumer awareness of the reduction might be irrelevant in a real-life scenario. A simultaneous reduction of Na-lactate and salt did not affect microbial stability (psychrotrophic and LAB counts) of the product. Reducing sodium-containing additives might be a low cost, promising strategy to reduce total sodium content in cooked sausages with no detrimental of their physicochemical, sensory and microbiological characteristics.

Effects of Microencapsulated Blend of Organic Acids and Essential Oils as a Feed Additive on Quality of Chicken Breast Meat

The present study aims to investigate the effect of dietary supplementation based on a blend of microencapsulated organic acids (sorbic and citric) and essential oils (thymol and vanillin) on chicken meat quality. A total of 420 male Ross 308 chicks were randomly assigned to two dietary treatments: the control group was fed with conventional diet (CON), while the other group received the control diet supplemented with 0.5% of a microencapsulated blend of organic acids and essential oils (AVI). In breast meat samples, intramuscular fat content and saturated/polyunsaturated fatty acids ratio were reduced by AVI supplementation (p < 0.05). Moreover, atherogenic (p < 0.01) and thrombogenic (p < 0.05) indices were lower in AVI than CON treatment. AVI raw meat showed a lower density of psychrotrophic bacteria (p < 0.05) at an initial time, and higher loads of enterococci after 4 days of refrigerated storage (p < 0.05). No contamination of Listeria spp., Campylobacter spp., and Clostridium spp. was found. TBARS values of the cooked meat were lower in the AVI treatment compared to CON (p < 0.01). Among colour parameters, a*, b* and C* values increased between 4 and 7 days of storage in AVI cooked meat (p < 0.05). Overall, organic acids and essential oils could improve the quality and shelf-life of poultry meat.

Replacement of nitrite with lupulon-xanthohumol loaded nanoliposome in cooked beef-sausage: experimental and model based study

Replacement of nitrite with hop components in cooked beef-sausage (CBS) was studied. For this purpose, lupulon-xanthohumol loaded nanoliposome (L-X-NL) was produced using sonication at optimized condition (time = 10.8 min, power = 72.7 W, lecithin concentration = 140 mg/mL). The release of lupulon and xanthohumol to liquid meat extract followed the Rigter-Peppus model. Samples of CBS (60% meat) supplemented by different ratios of nitrite/L-X-NL were produced. Microbial analysis and lipid oxidation measurement were carried out to evaluate the safety of CBS samples. The formulation consisted 30 ppm of nitrite and 150 ppm of L-X-NL remained microbiologically safe during 30-d storage at 4 °C. It was observed that L-X-NL could postpone the oxidation. Addition of L-X-NL has not impaired the sensory properties of final product, while the presence of nitrite for inducing the demanding color of CBS was important. Considering the results, partial removal of nitrite in formulation of CBS (up to 50%) and replacing with L-X-NL as a new promising preservative is recommended.

Antibacterial activity and mechanism of linalool against Pseudomonas aeruginosa

The purpose of this study was to evaluate the antibacterial activity and mechanism of linalool against Pseudomonas aeruginosa. The determination of antibacterial activity was based on the minimum inhibitory concentration (MIC) and the minimum bactericide concentration (MBC). Further, the antibacterial mechanism was explored by a growth curve assay, scanning electron microscopy (SEM), cell membrane permeability, membrane potential and respiratory chain dehydrogenase determination. The MIC and the MBC of linalool were 431 μg/mL and 862 μg/mL, respectively. The growth curve assay showed that the growth of P. aeruginosa was inhibited. The results of SEM revealed that linalool disrupted the normal morphology of the cell. The release of nucleic acids as well as the decrease in the membrane potential proved that the membrane integrity of P. aeruginosa was destroyed. Moreover, the respiratory chain was damaged by respiratory chain dehydrogenase determination as the absorbance at 490 nm decreased. This research suggested that it was possible for linalool to become a preservative of food by destroying the cell membrane, resulting in cell death.

Plants: A natural solution to enhance raw milk cheese preservation?

Plants have been traditionnally used for centuries in cheese manufacturing, either for their aromatic properties or as technological auxiliaries (e.g. milk-clotting enzyme preparations, cheese wrappers). Some of these plants are known to have antimicrobial and/or antioxidant properties and could also act as natural preservatives for raw milk and derived dairy products. This review examined the traditional uses of plants in dairy processing, and then focuses on known antimicrobial and antioxidant properties of their extracts (e.g. maceration, decoction, essential oil). Known effects of theses plants on technological flora (starter cultures and microorganisms implicated in cheese ripening) were also summarized, and the potential for plant extracts used in combination with hurdle technologies was explored. Then, legal restriction and bioactivity variations from a culture media to a food matrix was reviewed: non-toxic bioactive molecules found in plants, extract preparation modes suitable with foodgrade processing restrictions, the role of the food matrix as a hindrance to the efficiency of bioactive compounds, and a review of food legislation. Finally, some commercial plant extracts for milk preservation were discussed.

Microbial Growth and Biogenic Amine Production in a Balkan-Style Fresh Sausage during Refrigerated Storage under a CO2-Containing Anaerobic Atmosphere: Effect of the Addition of Zataria multiflora Essential Oil and Hops Extract

Fresh sausages are highly perishable, and the preservatives allowed in these types of meat preparations are limited. Balkan-style fresh sausages were prepared in triplicate without antimicrobials (Control), with an aqueous hops extract (30 mL/kg), with Zataria multiflora Boiss essential oil (1 mL/kg), or a combination of both (15 and 0.5 mL/kg, respectively), and refrigerator-stored under a 20% CO₂ and 80% N₂ atmosphere. The spoilage microbial growth, i.e., lactic acid bacteria (LAB), Brochothrix thermosphacta, Enterobacteriaceae, Micrococcaceae, molds and yeasts, the pH value, and the production of biogenic amines in the sausages were monitored weekly and compared with a control sausage during a 35-day storage period. Furthermore, 349 colonies of presumptive LAB (isolated from the De Mann, Rogose-Sharpe agar plates) were identified using a MALDI-TOF-based method. Growth levels to ≈ 9 Log colony forming units (CFU) per g were reached by LAB, with a predominance of Lactobacillus sakei. Enterobacteriaceae and B. thermosphacta also showed significant growth (up to 6 Log CFU/g). Biogenic amine levels increased, and tyramine values overcame 250 mg/kg. The study could not demonstrate a significant effect of antimicrobial source treatments in any of the characteristics studied, and thus, the shelf-life of sausages.

Effect of the addition of antimicrobial oregano (Origanum vulgare) and rosemary (Rosmarinus officinalis) essential oils on lactic acid bacteria growth in refrigerated vacuum-packed Tuscan sausage

Lactic acid bacteria are the main bacterial group associated to meat spoilage. Herbal essential oils are promising alternatives that can be used to retard lactic acid bacterial growth and extend shelf life of meat products. In this study, the influence of oregano and rosemary essential oils on the growth of lactic acid bacteria and the physicochemical properties of refrigerated vacuum-packed Tuscan sausage was evaluated. In addition to the control (without the addition of oil), the sausage samples were separately treated with different concentrations of each essential oil (0.05 wt%, 0.1 wt%, 0.2 wt%, and 0.4 wt%). The shelf life was evaluated as the time to the lactic acid bacteria population to reach the levels of 10⁶ and 10⁷ CFU/g. After the addition of 0.05 wt% and 0.1 wt% of essential oil to the sausage, the rosemary essential oil provided a higher extension of the shelf life of the sausages (approximately 3 and 5 days, respectively) than the oregano essential oil (approximately 1 and 3 days, respectively). After adding 0.2 wt% and 0.4 wt% of essential oil, the oregano essential oil resulted in a larger increase of the shelf life of the samples (about 8 and 14 days, respectively) when compared with the rosemary essential oil (about 7 to 11 days, respectively). All the treatments slowed the growth of the lactic acid bacteria but they did not change the maximum bacterial population. New empirical models that relate the shelf life of the sausage and the maximum specific growth rate of the lactic acid bacteria with the oil concentration were obtained. These results can be applied to model the influence of essential oils on the shelf life of different meat products.

Growth Biocontrol of Foodborne Pathogens and Spoilage Microorganisms of Food by Polish Propolis Extracts

Propolis is a natural mixture produced by bees from plant resin substances. This study focuses on the general characteristics of five samples of Polish extract propolis originating from agricultural areas. Chemical composition with high performance liquid chromatography‒diode array detector method, total content of flavonoids and polyphenols, and antioxidative activity were determined in the ethanol extracts of propolis (EEP) samples. Minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC) and time-kill curves were studied for foodborne pathogens and food spoilage microorganisms. In EEPs the predominant flavonoid compounds were pinocembrin, chrysin, pinobanksin, apigenin, and kaempferol and the predominant phenolic acids were p-coumaric acid, ferulic acid, and caffeic acid. A strong antioxidative action of propolis in vitro was observed (IC50 for DPPH radical was at the level of 0.9-2.1 µg/mL). EEPs had MIC values for bacteria in the range of 1-16 mg/mL, whereas MIC for fungi ranged from 2 to 32 mg/mL. Extract of propolis originating from southern Poland was distinguished by higher content of bioactive components, and stronger antioxidative and antimicrobial activity than EPPs from the remaining areas of Poland. The results indicate the possibility of applying ethanol extracts from Polish propolis to protect food against microbiological spoilage.

Food Preservative Capabilities of Grape (Vitis vinifera) and Clementine Mandarin (Citrus reticulata) By-products Extracts in South Africa

The drive towards sustainable food systems coupled with increased consumer sophistication have prompted innovation in waste valorization. Grape and citrus processing by-products, abundant in the Mediterranean and tropical regions, respectively, are expanding and are sustainable sources of bioactive phytochemicals that can be used as natural preservatives for foods. Phytochemical composition, antioxidant, and antimicrobial properties of extracts from grape pomace (GPE), seeds (GSE), and clementine mandarin peel and pulp (MPE) grown in South Africa were analyzed. Total phenols and carotenoids were highest in GPE followed by GSE and MPE (p ≤ 0.05). Flavonoids and anthocyanins were higher (p ≤ 0.05) in GPE and GSE compared to MPE. The GSE had the highest proanthocyanidins content followed by GPE and MPE (p ≤ 0.05). Ascorbic acid was only detected in MPE, which also had the highest titratable acidity and lowest pH values (p ≤ 0.05). The GSE had the highest antioxidant potency composite index followed by GPE and MPE (p ≤ 0.05). The order of antimicrobial activity of the extracts was MPE > GSE > GPE (p ≤ 0.05). Current findings show that GSE is a potential antioxidant while MPE holds promise as an antimicrobial for the food industry.