Comparative study on effect of pomegranate peel powder as natural preservative and chemical preservatives on quality and shelf life of muffins.

This research aims to investigate the potential of utilizing pomegranate peel powder (PPP) as a natural preservative in muffin preparation. Pomegranate peel is a rich source of bioactive compounds, including phenolics, flavonoids, and tannins, which possess high antioxidant and antimicrobial properties. The In-Vitro antifungal activity of pomegranate peel powder (8% PPP), potassium sorbate (0.1% PS) and calcium propionate (0.5% CP) was assessed against Penicillium sp. and Aspergillus sp. using poison food technique. The PPP showed the anti-fungal activity by delaying the growth of microorganism on media plate similar to the PS and CP. The effect of utilization of PPP on quality characteristics of muffins were compared with the muffins with chemical preservatives (0.1% PS and 0.5% CP). The viscosity and specific gravity of batter significantly increased from 7.98 to 11.87 Pa s and 1.089-1.398 respectively on addition of 8% PPP. The optical microscopic structure of PPP added batter revealed the decrease in the number of air cells from 24 to 12 with radius range of 6.42-72.72 µm and area range of 511.03-15,383.17 µm2. The functional properties of flour with PPP had higher water absorption capacity, foaming stability, emulsification activity and emulsion stability than others. The addition of PPP significantly increase the weight (32.83 g), and decrease the height (31.3 mm), volume (61.43 cm3), specific volume (1.67 cm3/g) and baking loss (10.19%). The 418.36% increase in fibre content, 14.46% and 18.46% decrease in carbohydrates and energy value was observed in muffin with 8% PPP as compared to control respectively. The total phenols was increased from 0.92 to 12.5 mg GAE/100 g, total tannin from 0.2 to 8.27 mg GAE/100 g, In-vitro antioxidant activity by DPPH from 6.97 to 29.34% and In-vitro antioxidant activity by FRAP from 0.497 to 2.934 mg AAE/100 g in muffins added with 8% PPP. The muffin with PPP was softer than control and muffin with 0.1% PS. The addition of PPP resulted to improve in muffin texture but taste slightly bitter. During the storage of muffins at room temperature (27-30 °C), the moisture content of muffin with PPP was reduced from 17.04 to 13.23% which was higher than the rest of the treatments. Similarly, the hardness of sample with PPP was higher than the sample with 0.5% CP, but lowers than control and sample with 0.1% PS throughout the storage period. The results suggest that pomegranate peel powder can be successfully used as a natural preservative in place of chemical preservatives in muffins, to extend the shelf life. This study provides the opportunity to use PPP as functional ingredient and natural preservative in different bakery products.

Natural approach of using nisin and its nanoform as food bio-preservatives against methicillin resistant Staphylococcus aureus and E.coli O157:H7 in yoghurt.

BACKGROUND: Natural antimicrobial agents such as nisin were used to control the growth of foodborne pathogens in dairy products. The current study aimed to examine the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against methicillin resistant Staphylococcus aureus (MRSA) and E.coli O157:H7 during the manufacturing and storage of yoghurt. Nisin NPs were prepared using new, natural, and safe nano-precipitation method by acetic acid. The prepared NPs were characterized using zeta-sizer and transmission electron microscopy (TEM). In addition, the cytotoxicity of nisin NPs on vero cells was assessed using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined using agar well-diffusion method. Further, fresh buffalo's milk was inoculated with MRSA or E.coli O157:H7 (1 × 106 CFU/ml) with the addition of either nisin or nisin NPs, and then the inoculated milk was used for yoghurt making. The organoleptic properties, pH and bacterial load of the obtained yoghurt were evaluated during storage in comparison to control group. RESULTS: The obtained results showed a strong antibacterial activity of nisin NPs (0.125 mg/mL) against MRSA and E.coli O157:H7 in comparison with control and pure nisin groups. Notably, complete eradication of MRSA and E.coli O157:H7 was observed in yoghurt formulated with nisin NPs after 24 h and 5th day of storage, respectively. The shelf life of yoghurt inoculated with nisin nanoparticles was extended than those manufactured without addition of such nanoparticles. CONCLUSIONS: Overall, the present study indicated that the addition of nisin NPs during processing of yoghurt could be a useful tool for food preservation against MRSA and E.coli O157:H7 in dairy industry.

Metal-organic frameworks-based moisture responsive essential oil hydrogel beads for fresh-cut pineapple preservation.

The preservation of fresh-cut fruits and vegetables has attracted attention to the shelf-life reduction caused by high humidity. Herein, alginate/copper ions cross-linking, in-situ growth and self-assembly techniques of metal-organic frameworks (MOFs) were utilized to prepare a moisture responsive hydrogel bead (HKUST-1@ALG). As the multistage porous structure formation, tea tree essential oil (TTO) load capacity in hydrogel bead (TTO-HKUST-1@ALG) was increased from 6.1% to 21.6%. TTO-HKUST-1@ALG had excellent moisture response performance, and the release rates of TTO increased from 33.89% to 70.98% with moisture increasing from 45% to 95%. Besides, TTO-HKUST-1@ALG exhibited excellent antimicrobial, antioxidant capacity, and biocompatibility. During storage, TTO-HKUST-1@ALG effectively improved the cell membrane integrity by maintaining the balance of reactive oxygen species metabolism. The degradation of cell wall structure and tissue softening were delayed by inhibiting the cell wall-degrading enzymes activity. Briefly, TTO-HKUST-1@ALG improved the storage quality and extended shelf-life of fresh-cut pineapple, which was a promising preservative.

Determination of Post-Fermentation Waste from Fermented Vegetables as Potential Substitutes for Preservatives in o/w Emulsion.

Post-fermentation wastes are rich sources of various biologically active compounds with antimicrobial activity, whose potential is not being fully exploited. One of the possible applications of post-fermentation waste may be its use as a natural preservative that effectively combats pathogens found in formulations. The study aims included the following: (1) compare the antimicrobial and antioxidant activity of fermented vegetable extracts (FVEs), (2) examine the inhibition of cosmetic-borne pathogens by FVEs, and (3) estimate the preservative effectiveness of FVEs in o/w emulsions. It was found that fermented white cabbage, cucumber, celery, and the mixture of fermented white cabbage, cucumber, and celery (1:1:1) showed antibacterial and antifungal activity against all the tested reference microbial strains. The addition of fermented cucumber, celery, and the mixture of fermented white cabbage, cucumber, and celery (1:1:1) to the o/w emulsion fulfilled criterion A of the preservative effectiveness test for S. aureus, E. coli, and A. brasiliensis, but did not fulfill the criterion for P. aeruginosa and C. albicans. The tested FVEs have comparable activity to inhibit pathogens in o/w emulsion as sodium benzoate. The results of our study prove that FVEs can be valuable raw materials supporting the preservative system, which, in turn, can significantly reduce the concentration of preservatives used in o/w emulsion.

The role of food preservatives in shaping metabolic profile and chemical sensitivity of fungi - an extensive study on crucial mycological food contaminants from the genus Neosartorya (Aspergillus spp.).

Food preservatives are crucial in fruit production, but fungal resistance is a challenge. The main objective was to compare the sensitivity of Neosartorya spp. isolates to preservatives used in food security applications and to assess the role of metabolic properties in shaping Neosartorya spp. resistance. Sodium metabisulfite, potassium sorbate, sodium bisulfite and sorbic acid showed inhibitory effects, with sodium metabisulfite the most effective. Tested metabolic profiles included fungal growth intensity and utilization of amines and amides, amino acids, polymers, carbohydrates and carboxylic acids. Significant decreases in the utilization of all tested organic compound guilds were observed after fungal exposure to food preservatives compared to the control. Although the current investigation was limited in the number of predominately carbohydrate substrates and the breadth of metabolic responses, extensive sensitivity panels are logical step in establishing a course of action against spoilage agents in food production being important approach for innovative food chemistry.

Sanxiapeptin is an ideal preservative with a dual effect of controlling green mold and inducing systemic defense in postharvest citrus.

Green mold is a common postharvest disease infected by Penicillium digitatum that causes citrus fruit decay, and severely affects fruit storage quality. This work aimed to investigate the antifungal activity of Sanxiapeptin against P. digitatum, and elucidate the possible mechanisms involved. Sanxiapeptin was capable of inhibiting spore germination, germ tube length and mycelial growth. The SYTOX green staining assay revealed that Sanxiapeptin targeted the fungal membrane, and changed the membrane permeability, leading to the leakage of cell constituents. Meanwhile, Sanxiapeptin could influence the cell wall permeability and integrity by increasing the activities of chitinase and glucanase, resulting in abnormal chitin consumption and the decrease of glucan. Intriguingly, Sanxiapeptin could effectively control postharvest decay in citrus fruits, and activate the host resistance responses by regulating the phenylpropanoid pathway. In conclusion, Sanxiapeptin exhibits multiphasic antifungal mechanisms of action to control green mold in citrus fruits, shows great potential as novel food preservatives.

Milk-derived antimicrobial peptides incorporated whey protein film as active coating to improve microbial stability of refrigerated soft cheese.

Nisin is the first FDA-approved antimicrobial peptide and shows significant antimicrobial activity against Gram-positive bacteria, but only a weakly inhibitory effect on Gram-negative bacteria. The aim of this study was to prepare whey protein-based edible films with the incorporation of milk-derived antimicrobial peptides (αs2-casein151-181 and αs2-casein182-207) and compare their mechanical properties and potential application in cheese packaging with films containing nisin. These two antimicrobial peptides showed similar activity against B. subtilis and much higher activity against E. coli than bacteriocin nisin, representing that these milk-derived peptides had great potential to be applied as food preservatives. Antimicrobial peptides in whey protein films caused an increase in film opaqueness and water vapor barrier properties but decreased the tensile strength and elongation at break. Compared to other films, the whey protein film containing αs2-casein151-181 had good stability in salt or acidic solution, as evidenced by the results from scanning electron microscope and Fourier transform infrared spectroscopy. Whey protein film incorporated with αs2-casein151-181 could inhibit the growth of yeasts and molds, and control the growth of psychrotrophic bacteria present originally in the soft cheese at refrigerated temperature. It also exhibited significant inhibitory activity against the development of mixed culture (E. coli and B. subtilis) in the cheese due to superficial contamination during storage. Antimicrobial peptides immobilized in whey protein films showed a higher effectiveness than their direct application in solution. In addition, films containing αs2-casein151-181 could act as a hurdle inhibiting the development of postprocessing contamination on the cheese surface during the 28 days of storage. The films in this study exhibited the characteristics desired for active packaging materials.

Common food preservatives impose distinct selective pressures on Salmonella Typhimurium planktonic and biofilm populations.

Food preservatives are crucial in controlling microbial growth in processed foods to maintain food safety. Bacterial biofilms pose a threat in the food chain by facilitating persistence on a range of surfaces and food products. Cells in a biofilm are often highly tolerant of antimicrobials and can evolve in response to antimicrobial exposure. Little is known about the efficacy of preservatives against biofilms and their potential impact on the evolution of antimicrobial resistance. In this study we investigated how Salmonella enterica serovar Typhimurium responded to subinhibitory concentrations of four food preservatives (sodium chloride, potassium chloride, sodium nitrite or sodium lactate) when grown planktonically and in biofilms. We found that each preservative exerted a unique selective pressure on S. Typhimurium populations. There was a trade-off between biofilm formation and growth in the presence of three of the four preservatives, where prolonged preservative exposure resulted in reduced biofilm biomass and matrix production over time. All three preservatives selected for mutations in global stress response regulators rpoS and crp. There was no evidence for any selection of cross-resistance to antibiotics after preservative exposure. In conclusion, we showed that preservatives affect biofilm formation and bacterial growth in a compound specific manner. We showed trade-offs between biofilm formation and preservative tolerance, but no antibiotic cross-tolerance. This indicates that bacterial adaptation to continuous preservative exposure, is unlikely to affect food safety or contribute to antibiotic resistance.

The inhibition mechanism of PostbioYDFF-3 on quality deterioration of refrigerated grass carp fillets from the perspective of endogenous enzyme and microorganisms changes.

The protective mode of PostbioYDFF-3 (referred to as postbiotics) on the quality stability of refrigerated fillets was explored from the aspects of endogenous enzyme activity and the abundance of spoilage microorganisms. Compared to the control group, the samples soaked in postbiotics showed significant reductions in TVC, TVB-N and TBARS values by 39.6%, 58.6% and 25.5% on day 5, respectively. In addition, the color changes, biogenic amine accumulation and texture softening of the fish fillets soaked in postbiotics were effectively suppressed. Furthermore, the activity of endogenous enzyme activities was detected. The calpain activities were significantly inhibited (p < 0.05) after soaking in postbiotics, which declined by 23%. Meanwhile, high throughput sequencing analysis further indicated that the growth of spoilage microorganism such as Acinetobacter and Pseudomonas were suppressed. Overall, the PostbioYDFF-3 was suitable for preserving fish meat.

A combined approach of lauroyl arginine ethyl ester hydrochloride and kojic acid in mitigating fresh-cut potato deterioration.

The combinational effects of kojic acid and lauroyl arginine ethyl ester hydrochloride (ELAH) on fresh-cut potatoes were investigated. Kojic acid of 0.6% (w/w) effectively inhibited the browning of fresh-cut potatoes and displayed antimicrobial capacity. The color difference value of samples was decreased from 175 to 26 by kojic acid. In contrast, ELAH could not effectively bind with the active sites of tyrosinase and catechol oxidase at molecular level. Although 0.5% (w/w) of ELAH prominently inhibited the microbial growth, it promoted the browning of samples. However, combining kojic acid and ELAH effectively inhibited the browning of samples and microbial growth during the storage and the color difference value of samples was decreased to 52. This amount of kojic acid inhibited enzyme activities toward phenolic compounds. The results indicated that combination of kojic acid and ELAH could provide a potential strategy to extend the shelf life of fresh-cut products.

Design of a Novel Lysine Isopeptide 1018KI11 with Potent Antimicrobial Activity as a Safe and Stable Food Preservative Candidate.

Antimicrobial peptides are potent food additive candidates, but most of them are sensitive to proteases, which limits their application. Therefore, we substituted arginine for lysine and introduced a lysine isopeptide bond to peptide IDR-1018 in order to improve its enzymatic stability. Subsequently, the protease stability and antimicrobial/antibiofilm activity of the novel peptides (1018K2-1018KI11) were investigated. The data revealed that the antienzymatic potential of 1018KI11 to bromelain and papain increased by 2-8 folds and 16 folds, respectively. The minimum inhibitory concentration (MIC) of 1018KI11 against methicillin-resistant Staphylococcus aureus (MRSA) ATCC43300 and Escherichia coli (E. coli) ATCC25922 was reduced 2-fold compared to 1018K11. Mechanism exploration suggested that 1018KI11 was more effective than 1018K11 in disrupting the cell barrier and damaging genomic DNA. Additionally, 1018KI11 at certain concentration conditions (2-64 µg/mL) reduced biofilm development of MRSA ATCC43300 by 4.9-85.9%. These data indicated that novel peptide 1018KI11 is a potential food preservative candidate.

Recent advances in spoilage mechanisms and preservation technologies in beef quality: A review.

Beef is a popular meat product that can spoil and lose quality during postharvest handling and storage. This review examines different preservation methods for beef, from conventional techniques like low-temperature preservation, irradiation, vacuum packing, and chemical preservatives, to novel approaches like bacteriocin, essential oil, and non-thermal technologies. It also discusses how these methods work and affect beef quality. The review shows that beef spoilage is mainly due to enzymatic and microbial activities that impact beef freshness, texture, and quality. Although traditional preservation methods can extend beef shelf life, they have some drawbacks and limitations. Therefore, innovative preservation methods have been created and tested to improve beef quality and safety. These methods have promising results and potential applications in the beef industry. However, more research is needed to overcome the challenges and barriers for their commercialization. This review gives a comprehensive and critical overview of the current and emerging preservation methods for beef and their implications for the beef supply chain.

Emulsified and Nanoemulsified Essential Oils in the Control of Clostridium botulinum and Clostridium sporogenes in Mortadella.

Clostridium botulinum is a foodborne pathogen responsible for severe neuroparalytic disease associated with the ingestion of pre-formed toxin in food, with processed meats and canned foods being the most affected. Control of this pathogen in meat products is carried out using the preservative sodium nitrite (NaNO2), which in food, under certain conditions, such as thermal processing and storage, can form carcinogenic compounds. Therefore, the objective was to use nanoemulsified essential oils (EOs) as natural antimicrobial agents, with the aim of reducing the dose of NaNO2 applied in mortadella. The antimicrobial activity of nanoemulsions prepared with mixtures of EOs of garlic, clove, pink pepper, and black pepper was evaluated on endospores and vegetative cells of C. botulinum and Clostridium sporogenes (surrogate model) inoculated in mortadella prepared with 50 parts per million NaNO2. The effects on the technological (pH, water activity, and color) and sensory characteristics of the product were also evaluated. The combinations of EOs and their nanoemulsions showed sporicidal effects on the endospores of both tested microorganisms, with no counts observed from the 10th day of analysis. Furthermore, bacteriostatic effects on the studied microorganisms were observed. Regarding the technological and sensorial characteristics of the product, the addition of the combined EOs had a negative impact on the color of the mortadella and on the flavor/aroma. Despite the strong commercial appeal of adding natural preservatives to foods, the effects on flavor and color must be considered. Given the importance of controlling C. botulinum in this type of product, as well as the reduction in the amount of NaNO2 used, this combination of EOs represents a promising antimicrobial alternative to this preservative, encouraging further research in this direction.

On the potential role of naturally occurring carboxylic organic acids as anti-infective agents: opportunities and challenges.

Carboxylic organic acids are intermediates of central carbon metabolic pathways (e.g. acetic, propionic, citric, and lactic acid) long known to have potent antimicrobial potential, mainly at acidic pHs. The food industry has been leveraging those properties for years, using many of these acids as preservatives to inhibit the growth of pathogenic and/or spoilage fungal and bacterial species. A few of these molecules (the most prominent being acetic acid) have been used as antiseptics since Hippocratic medicine, mainly to treat infected wounds in patients with burns. With the growth of antibiotic therapy, the use of carboxylic acids (and other chemical antiseptics) in clinical settings lost relevance; however, with the continuous emergence of multi-antibiotic/antifungal resistant strains, the search for alternatives has intensified. This prospective article raises awareness of the potential of carboxylic acids to control infections in clinical settings, considering not only their previous exploitation in this context (which we overview) but also the positive experience of their safe use in food preservation. At a time of great concern with antimicrobial resistance and the slow arrival of new antimicrobial therapeutics to the market, further exploration of organic acids as anti-infective molecules may pave the way to more sustainable prophylactic and therapeutic approaches.

The inhibitory action of lactocin 63 on deterioration of seabass (Lateolabrax japonicus) during chilled storage.

BACKGROUND: The bacteriocins, particularly derived from lactic acid bacteria, currently exhibit potential as a promising food preservative owing to their low toxicity and potent antimicrobial activity. This study aimed to evaluate the efficacy of lactocin 63, produced by Lactobacillus coryniformis, in inhibiting the deterioration of Lateolabrax japonicas during chilled storage, while also investigating its underlying inhibitory mechanism. The measurement of total viable count, biogenic amines, and volatile organic compounds were conducted, along with high-throughput sequencing and sensory evaluation. RESULTS: The findings demonstrated that treatment with lactocin 63 resulted in a notable retardation of bacterial growth in L. japonicas fish fillet during refrigerated storage compared with the water-treated and nisin-treated groups. Moreover, lactocin 63 effectively maintained the microbial flora balance in the fish fillet and inhibited the proliferation and metabolic activity of specific spoilage microorganisms, particularly Shewanella, Pseudomonas, and Acinetobacter. Furthermore, the production of unacceptable volatile organic compounds (e.g. 1-octen-3-ol, hexanal, nonanal), as well as the biogenic amines derived from the bacterial metabolism, could be hindered, thus preventing the degradation in the quality of fish fillets and sustaining relatively high sensory quality. CONCLUSION: The results of this study provide valuable theoretical support for the development and application of lactocin 63, or other bacteriocins derived from lactic acid bacteria, as potential bio-preservatives in aquatic food. © 2024 Society of Chemical Industry.

Nanoscale Pickering emulsion food preservative films/coatings: Compositions, preparations, influencing factors, and applications.

Pickering emulsion (PE) technology effectively addresses the issues of poor compatibility and low retention of hydrophobic active ingredients in food packaging. Nonetheless, it is important to recognize that each stage of the preparation process for PE films/coatings (PEFCs) can significantly influence their functional properties. With the fundamental considerations of environmental friendliness and human safety, this review extensively explores the potential of raw materials for PEFC and introduces the preparation methods of nanoparticles, emulsification technology, and film-forming techniques. The critical factors that impact the performance of PEFC during the preparation process are analyzed to enhance food preservation effectiveness. Moreover, the latest advancements in PE packaging across diverse food applications are summarized, along with prospects for innovative food packaging materials. Finally, the preservation mechanism and application safety have been systematically elucidated. The study revealed that the PEFCs provide structural flexibility, where designable nanoparticles offer unique functional properties for intelligent control over active ingredient release. The selection of the dispersed and continuous phases, along with component proportions, can be customized for specific food characteristics and storage conditions. By employing suitable preparation and emulsification techniques, the stability of the emulsion can be improved, thereby enhancing the effectiveness of the films/coatings in preserving food. Including additional substances broadens the functionality of degradable materials. The PE packaging technology provides a safe and innovative solution for extending the shelf life and enhancing the quality of food products by protecting and releasing active components.

Utilizing functional genomics in Saccharomyces cerevisiae to characterize food preservative compounds: A pilot study.

Chemical preservatives are ubiquitously used to suppress the growth of or kill microorganisms across numerous industries, including the food industry. Utilizing yeast functional genomic techniques, genes and their functions can be observed at a genomic scale to elucidate how environmental stressors (e.g., chemical preservatives) impact microbial survival. These types of chemical genomics approaches can reveal genetic mutations that result in preservative resistance or sensitivity, assist in identification of preservative mechanism of action, and can be used to compare different preservatives for rational design of preservative mixtures. In this proof-of-concept study, we performed deletion and high-copy genetic expression screens to identify mutants that confer drug resistance to sodium benzoate, potassium sorbate, rosemary extract, and Natamax. By observing overlapping mutant genes between genetic screens, we were able to identify functional overlap between chemical preservatives and begin to explain mechanisms of action for these compounds.

Effects of potassium sorbate on systemic inflammation and gut microbiota in normal mice: A comparison of continuous intake and washout period.

Potassium sorbate (PS) is a widely used food preservative in the field of food industry. However, the effects of continuous intake and washout period of PS on host health are still unclear. In this study, to investigate long-term effect and after-effect of different concentrations and time points of PS, healthy mice were orally exposed to 150 mg/kg, 500 mg/kg and 1000 mg/kg of PS for 10 weeks, and washout treatment for another 5 weeks, respectively. The results indicated that PS intake for 10 weeks had no obvious effects on organs and adipose tissue, nor did it noteworthily interfere with glucolipid metabolism in the serum. However, it caused inflammatory cell infiltration in the liver, increased serum interleukin (IL)-1ß level, changed abundances of gut microbiota but failed to promote the production of short chain fatty acids in the gut. After washout period for 5 weeks, liver inflammation and IL-1ß level were decreased, and gut environment developed towards a healthier condition. Specifically, PS washout significantly increased abundance of Lachnospiraceae_NK4A136_group and the production of isobutyric acid. This study confirmed washout period eliminated negative effects from continuous intake of PS, which provided positive evidence for its safety.

Essential oils as green promising alternatives to chemical preservatives for agri-food products: New insight into molecular mechanism, toxicity assessment, and safety profile.

Microbial food spoilage caused by food-borne bacteria, molds, and associated toxic chemicals significantly alters the nutritional quality of food products and makes them unpalatable to the consumer. In view of potential adverse effects (resistance development, residual toxicity, and negative effects on consumer health) of some of the currently used preservative agents and consumer preferences towards safe, minimally processed, and chemical-free products, food industries are looking for natural alternatives to the chemical preservatives. In this context, essential oils (EOs) showed broad-range antimicrobial effectiveness, low toxicity, and diverse mechanisms of action, and could be considered promising natural plant-based antimicrobials. The existing technical barriers related to the screening of plants, extraction methods, characterization, dose optimization, and unpredicted mechanism of toxicity in the food system, could be overcome using recent scientific and technological advancements, especially bioinformatics, nanotechnology, and mathematical approaches. The review focused on the potential antimicrobial efficacy of EOs against food-borne microbes and the role of recent scientific technology and social networking platform in addressing the major obstacles with EOs-based antimicrobial agents. In addition, a detailed mechanistic understanding of the antimicrobial efficacy of EOs, safety profile, and risk assessment using bioinformatics approaches are summarized to explore their potential application as food preservatives.

Enhancing food preservation with postbiotic metabolites γ-aminobutyric acid (GABA) and bacteriocin-like inhibitory substances (BLIS) produced by Lactobacillus brevis C23 co-cultures in plant-based medium.

Lactic acid bacteria (LAB) can produce γ-aminobutyric acid (GABA) with antioxidant properties and sedative effects when it binds to the GABA receptor in the human brain. LAB can also produce bacteriocin-like inhibitory substances (BLIS) with antimicrobial capabilities during carbohydrate fermentation. GABA and BLIS are natural compounds with potential health benefits and food preservation properties. Lactobacillus brevis C23 was co-cultured with three different LABs as inducers, which produced the highest GABA content and BLIS activity. They were cultured in various plant-based media to obtain an edible and better-tasting final product over commercially available media like MRS broth. A coconut-based medium with additives was optimized using response surface methodology (RSM) to increase GABA and BLIS production. The optimized medium for maximum GABA production (3.22 ± 0.01 mg/mL) and BLIS activity (84.40 ± 0.44%) was a 5.5% coconut medium containing 0.23% glucose, 1.44% Tween 20, 0.48% L-glutamic acid, and 0.02% pyridoxine. Due to the presence of GABA, the cell-free supernatant (CFS) as a postbiotic showed higher antioxidant activity than other food preservatives like nisin and potassium sorbate. Finally, microbiological tests on food samples showed that the postbiotic was more effective than other preservatives at combating the growth of LAB, molds and coliform bacteria, making it a possible food preservative.