搜索结果：Preservatives

The preservative mechanism of chitosan coating on refrigerated sturgeon fillets was investigated using untargeted metabolomics and microbial diversity profiling over a 16-day period. Chitosan treatment significantly preserved endogenous antioxidant defenses (SOD: 63.46 U/mg protein) and delayed chemical deterioration, maintaining total volatile basic nitrogen at 9.54 mg/100 g. The results indicate that chitosan can fundamentally reshape microbial ecosystems, driving the niche exclusion of specific spoilage organisms and reducing the relative abundance of Pseudomonas from 93.83% in the control to 21.05% by day 12. Multi-omics integration revealed a strong covariance between microbial succession and metabolic evolution, indicating their coupled shifts. Under chitosan treatment, restricted Pseudomonas dominance coincided with attenuated histamine accumulation and stabilized glycerophospholipid and nucleotide metabolism. These findings provide a robust mechanistic basis for microbiota-metabolism interactions and identify quantitative biomarkers for the development of targeted aquatic biopreservatives.

The demand for natural preservatives has increased interests in antimicrobial peptides (AMPs) from Lactiplantibacillus plantarum. Beyond ribosomal bacteriocins, its proteolytic system generates AMPs from food proteins, with activities ranging from low μg mL-1 (purified peptides) to mg mL-1 (crude hydrolysates). In this process, cell-envelope proteinases initiate protein cleavage, Opp/DtpT systems transport peptides, and intracellular peptidases produce active AMPs. These amphipathic, hydrophobic and basic residue-rich peptides primarily form membrane pores or target the mannose phosphotransferase receptor. Applications in fermented foods show promise for biopreservation, shelf-life extension, texture improvement, and nitrite reduction. However, industrial translation is limited by yield variability, matrix interference, high purification costs, and the need for strain-specific safety evaluation. Future advances require an integrated strategy combining omics, CRISPR-based metabolic engineering, and microencapsulation to optimize yield, stability, and delivery. This review provides a roadmap for engineering L. plantarum as a natural bio-preservative factory for safer, clean-label fermented foods.

The Xinyu tangerine is a geographical indication agricultural product from Jiangxi province, China. During postharvest storage, nutrient loss and pathogen-induced decay reduce fruit quality. The selection of appropriate preservatives is therefore important for maintaining postharvest quality. Previous studies have shown that tea saponin-cinnamaldehyde nanoemulsion (TS-CNE) exhibits excellent antifungal activity and physicochemical properties suitable for citrus preservation. This study investigated the preservation efficacy and underlying mechanism of TS-CNE in Xinyu tangerines using metabolomics. The TS-CNE treatment maintained fruit firmness and color, reduced the decay rate, decreased malondialdehyde (MDA) and H2O2 accumulation in the peel, and increased the total phenolic, flavonoid, and anthocyanin content in the pulp. Untargeted metabolomic analysis showed that the levels of nobiletin, 4'-methoxyflavanone, kaempferol, neoliquiritin, deoxyloganic acid, xanthohumol, melilotoside, d-arabinose, and epigallocatechin in the peel were higher in the TS-CNE-treated group than in the control group. Treatment with TS-CNE can regulate pathways related to adenosine triphosphate-binding cassette (ABC) transporters, flavonoid biosynthesis, and phenylpropanoid biosynthesis. The TS-CNE treatment effectively preserved postharvest Xinyu tangerines. The preservation mechanism may involve reduced fruit decay during storage through increased accumulation of stress-responsive metabolites, including flavonoids and phenylalanine, in the peel. These findings provide a theoretical basis for the development and application of TS-CNE for postharvest disease control in citrus fruit. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Hypophosphites (also known as phosphinates) are the salts of hypophosphorous acid (also known as phosphinic acid), H3PO2. Various hypophosphite salts are known such as calcium hypophosphite (Ca(H2PO2)2) and sodium hypophosphite (Na(H2PO2)). Hypophosphites were proposed as a potential treatment for tuberculosis as early as the 1850s; however, they were found to be ineffective against this disease. Following this, there was a period of around 100 years during which no new studies on hypophosphites were published. Subsequent in vitro studies have shown that hypophosphites can be used as potential antibacterial food preservatives. Currently, calcium hypophosphite is used in commercial food supplements for children, as this compound is a suitable source of calcium ions. It also has other advantageous properties, including exceptionally high water solubility (154 g/L at 25 °C), a neutral taste, a high mass fraction of calcium per molecule (23.6%), and an excellent safety profile. Recent studies have shown its potential as an active ingredient in the field of oral care. Since biological mechanisms such as tooth and bone formation and natural remineralization due to saliva rely on calcium ions, calcium hypophosphite can be regarded as a biomimetic agent. Upon contact with phosphate from saliva, calcium hypophosphite forms hydroxyapatite; this imitation of physiological mineralization and crystallization processes in the human body further underlines its biomimetic character. This review summarizes and discusses the available literature on hypophosphites in human health and related fields.

Public health specialists continue to be concerned about the use of chemical preservatives in foodstuffs, particularly because of their bioaccumulative properties. This study aimed to detect benzoic acid residues in frozen poultry products in Iraq using high-performance liquid chromatography with a diode array detector. Twenty specimens were collected and analyzed, including 10 local and 10 imported poultry products. Chromatographic separation was performed on a C18 column (250 × 4.6 mm, 5 μm) using a mobile phase consisting of 30% acetonitrile in 0.1% trifluoroacetic acid at a flow rate of 1.0 ml/minute and detection at 235 nm. The benzoic acid standard solution (1,000 ppm ml⁻¹; CAS 65-85-0) gave a clear and sharp peak at 1.80 minutes, with an intensity of about 950-1,000 mAU. Calibration curves were constructed considering external calibration from 0.5 to 100-ppm ml-1 with R² .0.998 which obeyed outstanding linearity. The identification of benzoic acid in the test samples was confirmed as follows: the retention time of 1.79-1.82 minutes; spectral purity by Diode array detector (200-400 nm); peak ratio with criterion 5/20(25%). Among the analyzed samples, imported brands showed positive results in 4 out of 10 samples (40%), with concentrations ranging from 434 to 726 ppm ml⁻¹ (mean 595 ± 122 ppm ml⁻¹), whereas only 1 out of 10 locally produced brands (10%) tested positive at a concentration of 449 ppm ml⁻¹. No detectable peaks exceeding the detection limits were observed in the remaining samples within the 1.5-2.2-minute retention time window. The validated HPLC-DAD technique was found to be reliable and precise for the analysis of the preservative residue like benzoic acid, and can be considered an efficient technique for the control of food safety and protection of human health in Iraq.

Sorbic acid and its salts, listed as Sorbic Acid (SOA) and Potassium Sorbate (SOK) in the current Japan's Standard and Specification for Food Additives (JSFA), are widely used as food additive preservatives. In the JSFA monographs, titration is used as a quantitative method, and the SOA or SOK contents are quantified as sorbic acid or its salt, including their stereoisomers. Although sorbic acid can be converted into its stereoisomers under certain conditions, the actual isomer content in food additive products has not been accurately analyzed on the JSFA titration assay. In this study, we used a previously developed single-reference high-performance liquid chromatography (SR-HPLC) method to accurately analyze sorbic acid and its three isomers, enabling the individual quantification of these components in commercial SOA and SOK products used as food additives. Analysis of five lots of the SOA products and eight lots of the SOK products revealed that the 2E,4Z-isomer was the predominant stereoisomer, with contents ranging up to 0.011% in SOA and up to 0.15% in SOK. Thus, the stereoisomer content was extremely low compared with that of sorbic acid or potassium sorbate. The total contents of sorbic acid and the isomers in SOA or those of potassium sorbate and the isomers in SOK obtained using SR-HPLC were equivalent to those determined using the JSFA titration method. This suggests that the SR-HPLC method is a viable alternative to the titration-based quantitative method, enabling simultaneous quantification of stereoisomers in food additives. These findings demonstrate the utility of SR-HPLC as an alternative assay for regulatory and quality-control purposes, offering improved chemical specificity and stereoisomeric profiles compared with conventional titration methods.

Sulfites are widely used as preservatives in food and beverages and can also occur naturally during fermentation. Their presence may pose health risks to sensitive individuals, including those with contact dermatitis. Accurate quantification of sulfite concentrations in consumer products is essential for regulatory compliance and public safety. Free sulfite ion content was measured in 15 U.S. beverages in each category, including red wine, white wine, liquor, liqueur, lagers, ales, fruited/malt beers and ciders, energy drinks/tea/coffee, pre-workout/protein drinks, kombucha, juice, and soft drinks. Testing was performed in duplicate using food-grade sulfite strips with purified water as the control. Wines contained the highest sulfite levels, with some samples reaching 250 parts per million (ppm). Beers varied, with ales being highest and lagers the lowest. Liqueurs averaged 21.33 ppm, while workout beverages were higher than soft drinks and energy drinks. Juices were mostly low, though one exceeded 100 ppm. Kombucha and liquors measured at or below 10 ppm. Findings highlight the need for stricter sulfite monitoring, improved labeling, and alternative preservation strategies to protect sulfite-sensitive individuals.

Recombinant poliovirus (PV) virus-like particle (VLP) antigens mimic the conformation of the surface proteins in native PVs (i.e., serotype-specific D-antigen epitopes). Since they lack genomes and are non-infectious, PV-VLPs offer the promise of a safer, next-generation polio vaccine compared to traditional inactivated (IPV) or attenuated live (OPV) vaccines. Sandwich D-antigen ELISA formats are commonly used to measure the in vitro potency values (relative D-antigen content, DU/mL) of unadjuvanted trivalent IPV antigens. If IPV is formulated with aluminum-salt adjuvants, however, a pretreatment step (i.e., adjuvant dissolution or antigen desorption) is required, which may compromise antigen integrity during sample handling. This work describes the development of three competitive ELISAs to measure the relative D-antigen content of aluminum-salt adjuvanted PV-VLPs (Types 1, 2, 3) without the need for pretreatment. First, key assay parameters were established, including specificity, accuracy, precision, linearity, limit of quantification, and stability-indication. Next, preformulation characterization studies were performed with these methods including (1) rank-ordering the inherent thermal stability profiles of the PV-VLPs (Types 1 > 3 > 2) in-solution and adsorbed to an aluminum phosphate adjuvant (AdjuPhos™, AP) and (2) determining the effect of formulation variables on the thermal stability profiles of AP-adsorbed PV-VLPs including antimicrobial preservatives (thimerosal, 2-PE) and five different antigens present in pediatric combination vaccines (D, T, wP, Hib, Hep B). The development and application of three competitive D-antigen ELISAs were demonstrated, and future use in formulation and storage stability studies with the AP-adjuvanted, trivalent PV-VLPs (Types 1, 2, 3) is discussed with the long-term goal to develop a stable, efficacious, multi-dose, hexavalent combination vaccine presentation.

Background: Essential oils (EOs) are promising natural antimicrobials against food-borne pathogens, yet their efficacy depends on complex chemical profiles that vary by species and origin. The evaluation of underexplored aromatic plants from the Peruvian Amazon may reveal novel bioactive agents. Methods: We chemically characterized six EOs from Aloysia citrodora, Arracacia xanthorrhiza (two cultivars), Baccharis genistelloides, Piper acutifolium, and Piper lanceifolium using GC-MS and assessed their antibacterial activity against Escherichia coli (ATCC 25922), Salmonella enterica (ATCC 14028), Enterococcus faecalis (ATCC 29212), and Staphylococcus aureus (ATCC 49476). Results: EOs of Aloysia citrodora and Arracacia xanthorrhiza cv. Yellow exhibited the strongest inhibition, effective against both Gram-positive and Gram-negative bacteria, potentially associated with higher relative abundances of oxygenated monoterpenes and aliphatic aldehydes. Dose-response analysis supported their superior antibacterial potency, with the lowest LD50 values observed for these oils. Oils rich in sesquiterpenes showed lower activity. Conclusions: These findings underscore the importance of EO chemical composition for antibacterial potency and suggest that select Amazonian EOs have potential as natural preservatives for food safety applications.

Meat has been regarded as a very healthy food because of its nutritional value; minced meat is a popular meal; however, microbial contamination may have negative impacts on meat quality and consumer health. The study aimed to estimate the bacteriological contamination and use of some chemical and natural preservatives in minced meat. Approximately 103 samples of minced meat were collected from different butchers in Al-Najaf province from December 2024 to March 2025 to monitor their microbiological quality. Biochemical and polymerase chain reaction techniques for 16S rRNA gene amplification were used to confirm the bacterial identity, and the effects of lactic acid (3%), rosemary volatile oil (2%), thyme oil (1.5%), and the combination of thyme (1.5%) and rosemary (2%) were used as antibacterial after immersing the samples with these substances following bacterial counts. Total coliforms, Escherichia coli, and Staphylococcus aureus were 70%, 58%, and 54%, respectively. Furthermore, the mean values of average bacterial counts of total coliform, E. coli, and S. aureus were 4.35, 3.73, and 3.43 CFU log10/g, respectively. Compared with the control, statistically significant differences (p < 0.05) were observed between the single and combination use of substances and lactic acid. The combination of rosemary and thyme was the most effective, resulting in a reduction of coliform, E. coli, and S. aureus (1.11, 1.95, and 1.42 CFU, respectively) after 7 days. The high levels of contamination detected in the minced meat are an indication of unhygienic production conditions, and the synergistic activity of rosemary and thyme was most effective in reducing contamination.

Foodborne pathogens such as Listeria monocytogenes and Bacillus cereus continue to pose serious threats to global food safety, driving demand for natural, consumer-friendly preservation strategies. Circular bacteriocins, a class of ribosomally synthesized antimicrobial peptides characterized by having covalently linked N- and C-termini, are promising candidates due to their superior stability and broad-spectrum activity. Here we describe pumicyclin A, a novel circular bacteriocin produced by two nearly identical but independently isolated Bacillus pumilus strains. Pumicyclin A exhibits a broad inhibitory spectrum against gram-positive bacteria and is particularly potent against Listeria species and B. cereus. Genomic analysis revealed a six-gene biosynthetic cluster, with the precursor peptide comprising a 32-amino-acid leader and a 64-amino-acid core, yielding a mature peptide of approximately 6,218 Da. A second downstream gene, encoding a smaller bacteriocin-like peptide, was found to be non-essential for pumicyclin A production. Notably, deletion mutagenesis of the leader peptide to a single methionine residue did not abolish activity, whereas specific substitutions near the circularization site were associated with loss of detectable activity, consistent with impaired biosynthesis (e.g., disrupted circularization, secretion, stability), and indicating key residues important for bacteriocin production. These results offer mechanistic insights into the production of long-leader circular bacteriocins and support pumicyclin A as a promising agent for food biopreservation.IMPORTANCEThere is an urgent need for safe and effective antimicrobial solutions to control foodborne pathogens and reduce reliance on conventional chemical preservatives. Circular bacteriocins represent a relatively unexplored class of antimicrobials with desirable features, such as high stability and potent antibacterial activity. This study identifies and characterizes pumicyclin A, a new circular bacteriocin from Bacillus pumilus, with potent anti-Listeria activity and unique biosynthetic characteristics. By dissecting the roles of the leader peptide and conserved residues near the circularization site, we provide novel insights into the structure-function relationships governing circular bacteriocin maturation. These findings lay the groundwork for future (circular) peptide engineering efforts and support the potential application of pumicyclin A as a natural and effective biopreservative to enhance food safety and prolong shelf life.

Fruit juices are valued for their antioxidant content and role in a balanced diet, prompting growing interest in novel, non-thermal processing technologies that better preserve nutritional and sensory qualities compared to traditional thermal methods. The purpose of this review was to determine the effect of various fruit juice processing methods on the content of bioactive compounds in fruit juices. This work compares thermal methods with emerging innovative methods such as high pressure processing, sonication, pulsed electric fields, cold atmospheric plasma, and high pressure homogenization. A review of the current literature indicates that sonication is a promising technique, enabling effective product preservation while maintaining its nutritional quality. Furthermore, sonication often does not reduce the antioxidant activity of fruit juices; in fact, they tend to have higher levels of polyphenols, anthocyanins, and vitamin C compared to thermal methods. High pressure processing is a method which eliminates preservatives and stabilizers, while effectively preserving the nutritional value. This method maintains the stability of bioactive compounds with antioxidant activity compared to pasteurization. Cold atmospheric plasma and high pressure processing have also demonstrated high potential, combining effective microbial control with substantial preservation of bioactive compounds. This work presents an up-to-date overview (2002-2026) of fruit juice processing technologies, emphasizing the importance of selecting appropriate preservation methods to optimize the nutritional quality of the final product. It also outlines future research directions and highlights the challenges associated with implementing innovative technological solutions in the fruit juice industry.

This study developed a novel synergistic antibacterial system combining &#x3b5;-poly-L-lysine (&#x3b5;-PL) and oregano essential oil (OEO) as a natural, non-thermal preservation strategy for fruits. Among &#x3b5;-PL combinations with seven different essential oils, OEO exhibited the strongest synergistic interaction, significantly enhancing antibacterial efficacy, compared to individual agents, likely through disruption of bacterial cell membranes and leakage of intracellular components. This effect was validated through integrated in vitro assays, in vivo application on strawberries, and in silico molecular docking analysis, which showed a binding energy of -7.8&#xa0;kcal/mol. The &#x3b5;-PL/OEO treatment reduced total viable counts to < 3.0 log CFU/g and extended shelf life by 5 days at room temperature. Furthermore, the treatment effectively preserved key quality parameters, including pH (2.69), titratable acidity (0.493%), total soluble solids (7.4 &#xb0;Brix), and reducing sugars (0.772&#xa0;g/100&#xa0;g), while minimizing weight loss to < 2.0%. These findings demonstrate that the &#x3b5;-PL/OEO combination represents a promising, sustainable alternative to synthetic preservatives, offering enhanced microbial safety and improved quality retention in perishable fruits.

The postharvest longevity of Zantedeschia aethiopica (cut calla lily) flowers is often limited by rapid microbial proliferation and water loss, leading to early wilting and reduced aesthetic quality. This research aimed to evaluate silver nitrate (AgNO&#x2083;), silver nanoparticles (AgNPs), and chlorogenic acid (CGA) as preservative agents to maintain physiological and biochemical quality and extend vase life in cut calla lily flowers. Each treatment was applied individually in a completely randomized design (CRD) with three replicates of seven inflorescences each (totaling 21 inflorescences per treatment), using seven vase solutions supplemented with 15 mmol L&#x207b;&#xb9; sucrose: distilled water (control), AgNO&#x2083; at 50 and 100&#xa0;mg L&#x207b;&#xb9;, AgNPs at 15 and 30&#xa0;mg L&#x207b;&#xb9;, and CGA at 15 and 30&#xa0;mg L&#x207b;&#xb9;. Treatments were evaluated at nine predetermined time points, after which their effects were assessed on vase life, water uptake, relative fresh weight (RFW%), relative chlorophyll index (SPAD), total soluble sugars (TSS), protein content, total phenolic content (TPC), hydrogen peroxide (H&#x2082;O&#x2082;), malondialdehyde (MDA), microbial proliferation at the stem base, and the activities of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). Data were analyzed using one-way ANOVA followed by Duncan's multiple range test (p&#x2009;&#x2264;&#x2009;0.05). These findings indicate that AgNPs and CGA significantly extended the shelf life of cut calla lily flowers, with optimal concentrations of 30&#xa0;mg L&#x207b;&#xb9; CGA and 30&#xa0;mg L&#x207b;&#xb9; AgNPs. The highest RFW% (101.7 and 101.02%) was obtained from treatment with 30&#xa0;mg L&#x207b;&#xb9; CGA on day 5 in both seasons. These treatments improved water uptake, reduced water loss, inhibited microbial activity at the stem base, and decreased microbial blockages in the xylem for up to 11 days. Furthermore, treatment with 30&#xa0;mg L&#x207b;&#xb9; CGA resulted in the highest values of relative chlorophyll index (66.05 and 65.08 SPAD in the first and second seasons, respectively), total protein content (26.09 and 23.08&#xa0;mg g&#x207b;&#xb9; FW, respectively), and soluble carbohydrates (2.47% and 2.40%, respectively). In addition, this treatment reduced H&#x2082;O&#x2082; and MDA accumulation and enhanced antioxidant enzyme activities. Briefly, our results highlight the use of CGA and AgNPs, as well as the potential of incorporating natural antioxidants as a sustainable alternative to conventional preservatives in postharvest floral management.

I investigated the key causes and mechanisms of skin sensitization, evaluated existing diagnostic methods, and proposed new strategies to reduce the risk for allergic reactions. My research focused on sensitization to cosmetic components, including synthetic fragrances, preservatives (i.e., methylisothiazolinone, chlorphenesin), and natural extracts. I used patch testing and molecular diagnostics based on pro-inflammatory markers (i.e., interleukin-6, tumor necrosis factor-alpha). Positive reactions occurred in 69.2% of participants, with synthetic fragrances (51.7%) and methylisothiazolinone (39.2%) as the most common allergens. Women aged 30-45 showed higher susceptibility to severe allergic responses. The study confirmed the effectiveness of patch testing and molecular diagnostics in accurately detecting and predicting skin allergies. Based on the findings, I recommend stricter regulation of sensitizing agents in cosmetics, the introduction of hypoallergenic alternatives, and a shift toward personalized product formulation. The results of my study also highlight the need for updated diagnostic standards, including non-invasive techniques and expanded molecular analyses as well as the revision of regulatory frameworks to enhance cosmetic safety and consumer well-being. Expanding professional knowledge in allergy diagnosis and prevention is essential for raising the standards of care and protecting the health of users.