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.

Antimicrobial and anti-aflatoxigenic activities of nanoemulsions based on Achillea millefolium and Crocus sativus flower extracts as green promising agents for food preservatives.

BACKGROUND: Although the mechanism of action of nanoemulsion is still unclear, the modern use of nanoemulsions made from natural extracts as antimicrobial and anti-aflatoxigenic agents represents a potential food preservation and a safety target. METHODS: Two natural nanoemulsion extracts of Crocus sativus (the saffron flower) and Achillea millefolium (the yarrow flower) were produced in the current study using a low-energy method that included carboxymethylcellulose and Arabic gum. The synthesized nanoemulsion was fully identified by different analytical methods. Detection of the volatile content was completed using GC-MS analysis. The antioxidant potential, and phenolic compounds content were analyzed in the extractions. The synthesized nanoemulsions were screened for their antimicrobial potential in addition to their anti-aflatoxigenic activity. RESULTS: The droplet size of Saffron flowers was finer (121.64 ± 2.18 nm) than yarrow flowers (151.21 ± 1.12 nm). The Zeta potential measurements of the yarrow flower (-16.31 ± 2.54 mV) and the saffron flower (-18.55 ± 2.31 mV) both showed high stability, along with low PDI values (0.34-0.41). The nanoemulsion of yarrow flower revealed 51 compounds using gas chromatography-mass spectrometry (GCMS), with hexanal (16.25%), ß-Pinene (7.41%), ß-Myrcene (5.24%), D-Limonene (5.58%) and Caryophyllene (4.38%) being the most prevalent. Additionally, 31 compounds were detected in the saffron nanoemulsion, with D-limonene (4.89%), isophorone (12.29%), 4-oxy isophorone (8.19%), and safranal (44.84%) being the most abundant. Compared to the nanoemulsion of the yarrow flower, the saffron nanoemulsion had good antibacterial and antifungal activity. Saffron nanoemulsion inhibited total fungal growth by 69.64-71.90% in a simulated liquid medium and demonstrated the most significant decrease in aflatoxin production. Infected strawberry fruits coated with nanoemulsion extracts exhibited high antimicrobial activity in the form of saffron flower and yarrow flower extract nanoemulsions, which inhibited and/or controlled the growth of Aspergillus fungi. Due to this inhibition, the lag phase was noticeably prolonged, the cell load decreased, and the stability time increased. CONCLUSION: This study will contribute to expanding the theoretical research and utilization of nanoemulsions as green protective agents in agricultural and food industries for a promising protection from the invasion of some pathogenic bacteria and fungi.

Insights into high-solids anaerobic digestion of food waste concomitant with sorbate: Performance and mechanisms.

High-solids anaerobic digestion (HS-AD) of food waste is increasingly applied commercially. Sorbate, a food preservative extensively used in the food industry, induces potential environmental risks. Results indicated sorbate at 0-10 mg/g volatile solids (VS) slightly inhibited methane production, and the cumulative methane yield suggested a negative correlation with 25 mg/g VS sorbate, with a reduction of 15.0% compared to the control (from 285.7 to 253.6 mL CH4/g VS). The reduction in methane yield could be ascribed to the promotion of solubilization and inhibition of acidogenesis and methanogenesis with sorbate addition. Excessive sorbate (25 mg/g VS) resulted in the inhibition of aceticlastic metabolism and the key enzymes activities (e.g., acetate kinase and coenzyme F420). This study deeply elucidated the response mechanism of HS-AD to sorbate, supplemented the potential ecological risk assessment of sorbate, and could provide insights to further prevent the potential risk of sorbate in anaerobic digestion of food waste.

Atividade in vitro de extratos e frações de Copernicia prunifera (Arecaceae) contra bactérias de importância clínica em saúde pública / In vitro activity of extracts and fractions of Copernicia prunifera (Arecaceae) against bacteria of clinical importance in public health / Actividad in vitro de extractos y fracciones de Copernicia prunifera (Arecaceae) frente a bacterias de importancia clínica en salud pública

Introdução: O aumento contínuo da resistência bacteriana aos antibióticos convencionais é um problema de importância global. Encontrar produtos como alternativas terapêuticas naturais é essencial. As plantas medicinais possuem uma composição química muito rica, que podem ser estruturalmente otimizadas e processadas em novos antimicrobianos. Objetivo: Avaliar o potencial antibacteriano frente a microrganismos humanos potencialmente patogênicos do extrato etanólico e frações de Copernicia prunifera. Metodologia: A triagem fitoquímica de plantas foi realizada usando métodos de precipitação e coloração e a atividade antibacteriana utilizando o método de difusão em disco e microdiluição em caldo contra cepas padronizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus. Resultados: A triagem fitoquímica revela a presença de taninos, flavonoides, esteroides, triterpernóides, saponinas e alcaloides. Os extratos etanólico e frações da casca do caule e folhas tiveram atividade inibitória contra S. aureus e K. pneumonie com zona de inibição que variou de 7,0±1,73 a 9,33±0,58 mm pelo método de difusão em disco. Pelo método de microdiluição em caldo os extratos foram satisfatórios somente contra K. pneumoniae (CIM = 125 a 1000 µg/mL) S. aureus, P. aeruginosa e E. coli se mostraram resistentes aos testes (CIM > 1000 µg/mL). Conclusão: Esses resultados fornecem uma base para futuras investigações em modelos in vivo, para que os compostos de C. prunifera possam ser aplicados no desenvolvimento de novos agentes antimicrobianos contra K. pneumoniae.

Introduction: The continuous increase in bacterial resistance to conventional antibiotics is a problem of global importance. Finding products as natural therapeutic alternatives is essential. Medicinal plants have a very rich chemical composition, which can be structurally optimized and processed into novel antimicrobials. Objective: To evaluate the antibacterial potential against potentially pathogenic human microorganisms of the ethanolic extract and fractions of Copernicia prunifera. Methodology: Phytochemical screening of plants was performed using precipitation and staining methods and antibacterial activity using the disk diffusion and broth microdilution method against standardized strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Results: Phytochemical screening reveals the presence of tannins, flavonoids, steroids, triterpernoids, saponins and alkaloids. The ethanolic extracts and fractions of stem bark and leaves had inhibitory activity against S. aureus and K. pneumonie with zone of inhibition ranging from 7.0±1.73 to 9.33±0.58 mm by disc diffusion method. By broth microdilution method the extracts were satisfactory only against K. pneumoniae (MIC = 125 to 1000 µg/mL) S. aureus, P. aeruginosa and E. coli were resistant to the tests (MIC > 1000 µg/mL). Conclusion: These results provide a basis for further investigation in in vivo models, so that compounds from C. prunifera can be applied in the development of new antimicrobial agents against K. pneumoniae.

Introducción: El continuo aumento de la resistencia bacteriana a los antibióticos convencionales es un problema de importancia mundial. Es esencial encontrar productos como alternativas terapéuticas naturales. Las plantas medicinales tienen una composición química muy rica, que puede optimizarse estructuralmente y transformarse en nuevos antimicrobianos. Objetivo: Evaluar el potencial antibacteriano frente a microorganismos humanos potencialmente patógenos del extracto etanólico y fracciones de Copernicia prunifera. Metodología: Se realizó el cribado fitoquímico de las plantas mediante los métodos de precipitación y tinción y la actividad antibacteriana mediante el método de difusión en disco y microdilución en caldo frente a cepas estandarizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa y Staphylococcus aureus. Resultados: El cribado fitoquímico revela la presencia de taninos, flavonoides, esteroides, triterpernoides, saponinas y alcaloides. Los extractos etanólicos y las fracciones de la corteza del tallo y las hojas presentaron actividad inhibitoria contra S. aureus y K. pneumonie con una zona de inhibición que osciló entre 7,0±1,73 y 9,33±0,58 mm por el método de difusión en disco. Por el método de microdilución en caldo, los extractos sólo fueron satisfactorios frente a K. pneumoniae (CMI = 125 a 1000 µg/mL). S. aureus, P. aeruginosa y E. coli fueron resistentes a las pruebas (CMI > 1000 µg/mL). Conclusiones: Estos resultados proporcionan una base para futuras investigaciones en modelos in vivo, de modo que los compuestos de C. prunifera puedan aplicarse en el desarrollo de nuevos agentes antimicrobianos contra K. pneumoniae.

Phenolic compounds in Nordic berry species and their application as potential natural food preservatives.

An increasing demand for natural food preservatives is raised by consumers. For Nordic berry species, abundance of phenolic compounds and potent activities of anti-oxidation and anti-bacteria enables a great potential as food preservatives. This review provides a systematic examination of current literature on phenolic profiles, anti-oxidative and anti-bacterial activities of various extracts of Nordic berry species, as well as the impact of various structure features of phenolics on the bioactivities. Special attention is placed on exploitation of leaves of berry species and pomaces after juice-pressing as side-streams of berry production and processing. The current progress and challenges in application of Nordic berry species as food preservatives are discussed. To fully explore the potential application of Nordic berry species in food industry and especially to valorize the side-streams of berry cultivation (leaves) and juice-pressing industry (pomaces), it is crucial to obtain extracts and fractions with targeted phenolic composition, which have high food preserving efficacy and minimal impact on sensory qualities of food products.

Potential synergistic effect of Alhagi graecorum ethanolic extract with two conventional food preservatives against some foodborne pathogens.

The present study aims to screen the anti-bacterial activity and synergistic interaction of A. graecorum Boiss. ethanolic extract with two food preservatives against five strains of foodborne bacteria. Disk diffusion and minimum inhibitory concentration were used for anti-bacterial assay, checkerboard assay and time-kill curve were used for the combination studies. HPLC analysis and molecular docking study were performed to corroborate the in vitro results. The ethanolic extract showed anti-bacterial activity against all tested bacterial strains with inhibition zones from 7.5 to 9.3 mm and MIC values ranged between 1.2 and 1.8 mg mL-1. The combination of the ethanolic extract with Na-benzoate or Na-propionate resulted in synergistic and additive interactions against the tested bacteria with fractional inhibitory concentration index (FICI) ranges 0.31-0.63 and no antagonism was shown. Time-kill curve assay showed that the synergistic and additive combinations have inhibitory effects on the tested strains. The ethanolic extract combination with Na-benzoate or Na-propionate can be used for development new sources of food preservatives. Testing new different natural plant extracts with food preservatives will help develop new anti-bacterial agents.

Natural bioactives in perspective: The future of active packaging based on essential oils and plant extracts themselves and those complexed by cyclodextrins.

Aiming to attend to consumers' increasing demand for synthetic additives-free food products (stimulated by personal preferences or health concerns), the food industry has been trying to introduce natural bioactive compounds as food preservatives. In this respect, the development of active food packaging incorporated with natural compounds could be of great interest. However, this scenario still has some particularities that can hinder its application in the food industry, such as relatively reduced stability and, in some cases, undesirable sensorial properties. Cyclodextrins showed up as an option to circumvent these drawbacks by forming inclusion complexes that can protect the active compounds and perform their controlled release for contact with packaged food. For industrial manufacturing of active packages based on naturally occurring bioactive compounds, inclusion complexation can be considered one of the most promising alternatives. Therefore, this review summarizes the potential of nanotechnology in active food packaging by applying cyclodextrins as a carrier for natural active compounds, which can be provided by conventional sources and alternatively (and cost-effectively) agro-food by-products. The present study will benefit prospects for exploring cyclodextrins in active food packaging, which industrial application, without a doubt, will increase in the coming years.

Antimicrobial, Pesticidal and Food Preservative Applications of Lemongrass Oil Nanoemulsion: A Mini-Review.

BACKGROUND: Essential oils that are extracted from plants have shown beneficial effects on humans and animals, evidenced by traditional medicine. They possess many essential phytocomponents that act as antimicrobial agents, and most of them are safe for external usage. INTRODUCTION: Lemongrass essential oil is extracted from the grass, such as Cymbopogon flexuosus, and is used for antimicrobial activity for a long time. The efficacy of this oil is limited due to the poor solubility and microbial penetration, easy vaporization, and lower stability. Nanoformulations and nanoencapsulations are nanotechnology fields that aim to improve the bioavailability of many natural compounds and enhance their stability. Lemongrass oil has also been nanoformulated as nanoemulsion, and various antimicrobial activities against various pathogens have been demonstrated, which are superior to free lemongrass oil. METHODOLOGY: We have used the search engines PubMed and Google Scholar for the mentioned keywords and selected the recent references related to this topic. CONCLUSION: In this review, we have discussed various antimicrobial properties of lemongrass essential oil nanoemulsion and its application, such as antibacterial, antifungal, pesticidal, food preservative, and antibiofilm activity.

Poly(ε-L-lysine) and poly(L-diaminopropionic acid) co-produced from spent mushroom substrate fermentation: potential use as food preservatives.

Poly(ε-L-lysine) and poly(L-diaminopropionic acid) are valuable homopoly (amino acids) with antimicrobial properties and mainly produced in submerged fermentation. In this study, we investigated their co-production using waste biomass and spent mushroom substrate in solid-state fermentation. Simultaneous production of poly(L-diaminopropionic acid) and poly(ε-L-lysine) was achieved in a single fermentation process using pearl oyster mushroom residues as substrate, with the supplement of glycerol and corn steep liquor. After optimization of the fermentation parameters, the maximum yield of poly(ε-L-lysine) and poly(L-diaminopropionic acid) reached 51.4 mg/g substrate and 25.4 mg/g substrate, respectively. The optimal fermentation conditions were 70% initial moisture content, pH of 6.5, 30°C and an inoculum size of 14%. Furthermore, the fermentation time was reduced from 8 days to 6 days using repeated-batch solid-state fermentation. Finally, the antimicrobial effects of poly(L-diaminopropionic acid) and poly(ε-L-lysine) were evaluated in freshly pressed grape juice, which indicated tremendous potential of this mixture in its use as biological preservative.

Application of oil-in-water nanoemulsions based on grape and cinnamon essential oils for shelf-life extension of chilled flathead mullet fillets.

BACKGROUND: The effect of nanoemulsions prepared with grape seed and cinnamon essential oils on the shelf-life of flathead mullet (Mugil cephalus) fillets was evaluated by determining physicochemical (pH, free fatty acids, peroxide value, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARs)), sensory and microbiological (mesophilic aerobic bacteria, total psychrophilic bacteria, and Enterobacteriaceae counts) properties during 14 day storage at 2 °C. RESULTS: The nanoemulsions showed good stability and low average droplet size. The results indicated that nanoemulsion treatments significantly prolonged the shelf-life of the fillets. Treatment inhibited increases in pH and TVB-N, and retarded lipid oxidation and hydrolysis. Sensory assessment revealed that treatment induced shelf-life extension from 10 to 14 days, compared with controls. Microbiological analyses showed nanoemulsion treatment caused shelf-life extension from 10 to 12 days with reduction of microbiological contamination by up to 1 log cfu g-1 in mesophilic and 1.5 log cfu g-1 in psychrotrophic bacteria. CONCLUSION: Considering the results, grape seed and cinnamon essential oil nanoemulsions could be considered as novel antimicrobial and antioxidant materials for shelf-life extension of flathead mullet fillets during cold storage. © 2021 Society of Chemical Industry.

Chemometric evaluation of functional components and anti-quorum sensing activity of mulberry leaves from Indian cultivars: a potential contribution to the food industry.

BACKGROUND: Potential use of many native, easily available vegetal materials for human consumption and value addition is not well recognized. Mulberry, being a traditional industrial crop rich in nutrients and nutraceuticals can be of great importance for the food industry. However, mulberry leaves are mainly being utilized in sericulture and are not exploited for their functional components. Thus, the selection of promising mulberry cultivars, rich in bioactive compounds, like resveratrol and 1-deoxynojirimycin, increase their potential use in functional foods. RESULTS: Chlorogenic acid, myricetin and kaempferol were the major polyphenols present in the nine selected cultivars, in the range 0.001-0.086, 0.003-0.079 and 0.003-0.163 g kg-1 fresh weight (FW), respectively. Protocatechuic acid, epicatechin and rutin were predominantly present in cultivars V-1, G-2 and ML (0.103, 0.080 and 0.121 g kg-1 FW, respectively). Similarly, resveratrol and 1-deoxynojirimycin were highest in cultivars ML and K-2 (0.078 and 0.079 g kg-1 FW, respectively). Leaf extracts of cultivars G-2 and ML were able to effectively inhibit the violacein production with 64.08% and 70.04%, respectively at the concentration of 6 mg mL-1 presumably due to a higher content of polyphenols. Chemometric evaluation of chromatographic data showed the intraspecific variability and secondary metabolite co-existence in different cultivars. CONCLUSIONS: Considering phytoconstituents, cultivars G-2, ML, K-2 and V-1 could contribute efficiently to the rational utilization of mulberry in agro-food industries. Furthermore, cultivars G-2 and ML leaves can be a new source of quorum sensing inhibitory agents. © 2021 Society of Chemical Industry.

Research to Support the Development of Front-of-Package Labeling Regulations for Food Products in the Americas: Methods, Tools, and Procedures

This publication explores the subject of front-of-package labeling (FOPL) for food products as a means to help combat the trend toward unhealthy eating. It analyzes the methods, tools, and procedures of research into FOPL with a view to enhancing its role in regulations governing food products in the Region of the Americas. The publication makes recommendations relating to FOPL research – how it should be conducted, how results should be communicated, how FOPL schemes should be selected, and what the priorities should be. It also contains useful annexes that include, for example, a focus group discussion guide, a questionnaire, and a protocol for FOPL research. The Americas is the region of the world with the highest prevalence of overweight and obesity in the world. In 2016, noncommunicable diseases (NCDs) were responsible for 78% of all deaths in the Region. Thirty-four percent of these NCD-related deaths occurred prematurely in people between the ages of 30 and 69 years. This implies that NCDs have a huge economic impact on societies. Unhealthy eating is the main modifiable factor that is driving this situation. In particular, consumption of ultra-processed products and of processed products that are nutrient poor and energy-dense and contain excessive levels of nutrients associated with NCDs has been identified as a main contributor to the epidemic of overweight and obesity. From a public health perspective, the efficacy and effectiveness of FOPL labeling will mainly depend on its ability to encourage consumers to make healthier food choices and to reduce the purchase and consumption of products that impair diets and health.

Pharmacokinetic characterization of carnosol from rosemary (Salvia Rosmarinus) in male C57BL/6 mice and inhibition profile in human cytochrome P450 enzymes.

Rosemary (Salvia Rosmarinus) is a rich source of dietary diterpenes with carnosol as one of the major polyphenols used to standardize rosemary extracts approved as a food preservative, however, at present there is not any information on the murine pharmacokinetic profile of carnosol or its potential for drug interactions. The present study utilizes cell-free, cell-based, and animal-based experiments to define the pharmacokinetic profile of the food based phytochemical carnosol. Mice were administered carnosol (100 mg/kg body weight) by oral gavage and plasma levels were analyzed by LC-MS/MS to establish a detailed pharmacokinetic profile. The maximum plasma concentration exceeded 1 µM after a single administration. The results are significant as they offer insights on the potential for food-drug interactions between carnosol from rosemary and active pharmaceutical ingredients. Carnosol was observed to inhibit selected CYP450 enzymes and modulate metabolic enzymes and transporters in in vitro assays.

The Effect of Ethanol Treatment on the Quality of a New Table Grape Cultivar It 681-30 Stored at Low Temperature and after a 7-Day Shelf-Life Period at 20 °C: A Molecular Approach.

Despite the fact that many studies have examined the effectiveness of different gaseous postharvest treatments applied at low temperature to maintain table grape quality, the use of ethanol vapor has hardly been investigated. Thus, this work has studied the effectiveness of ethanol vapor-generating sachets in the maintenance of It 681-30 table grape quality, a new cultivar, during storage at low temperature and after the shelf-life period at 20 °C. To this end, various quality assessments have been carried out and the effect of the ethanol treatment on the expression of different genes (phenylpropanoids, transcription factors, PRs, and aquaporins) was determined. The results indicated that the application of ethanol vapor reduced the total decay incidence, weight loss, and the rachis browning index in It 681-30 grapes stored at 0 °C and after the shelf-life period at 20 °C, as compared to non-treated samples. Moreover, the modulation of STS7 and the different PR genes analyzed seems to play a part in the molecular mechanisms activated to cope with fungal attacks during the postharvest of It 681-30 grapes, and particularly during the shelf-life period at 20 °C. Furthermore, the expression of aquaporin transcripts was activated in samples showing higher weight loss. Although further work is needed to elucidate the role of ethanol in table grape quality, the results obtained in this work provide new insight into the transcriptional regulation triggered by ethanol treatment.

Applications of Fruit Polyphenols and Their Functionalized Nanoparticles Against Foodborne Bacteria: A Mini Review.

The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed.

Biopreservative efficacy of grape (Vitis vinifera) and clementine mandarin orange (Citrus reticulata) by-product extracts in raw ground beef patties.

Beef patties were treated with 450 µg/g of extracts from grape (Vitis vinifera) seeds (GSE), pomace (GPE) or orange (Citrus reticulata) pomace (OPE) and compared to negative (no extract; CTR) and positive (sodium metabisulphite; SMB) controls for their effect on colour, lipid and protein oxidation and bacterial growth under simulated retail display conditions (4 °C) for 9 d, and sensory quality. Antioxidant activity and redness of beef patties increased in the order of CTR < OPE = GPE < GSE < SMB. The order of thiobarbituric acid reactive substances and carbonyl values were CTR > GPE = OPE > GSE > SBM, while that of bacterial counts were CTR > GSE = GPE > OPE > SMB. Retail display period had significant effect on all the shelf-life parameters. Overall, intensity of aroma, beef-like aroma and flavour in beef patties were highest in OPE. Results suggested that GSE and OPE could be commercially valorised as natural antioxidants and antibacterials in beef patties, respectively.

Effect of Cedrus deodara extract on the physiochemical and sensory properties of salted meat and its action mechanism.

The effect of pine needle extract from Cedrus deodara (PNE) on the quality of salted meat was reported, and its action mechanism was further investigated. With the treatment of PNE, the physicochemical properties of salted meat were improved. The peroxide value decreased from 16.18 to 6.78 mmol O2 /kg, while the thiobarbituric acid value decreased from 0.79 to 0.40 mg MDA/kg. Moreover, the salted meat with PNE also had the better texture, color, and volatile compositions. The 0.2% PNE group showed the highest ΔE value (63.16 ± 0.56), hardness (813.5 ± 48.7 g), and volatility (45.86 ± 0.39), while the control group showed the lowest ΔE value (43.92 ± 2.13), hardness (515.8 ± 17.3 g) and volatility (29.97 ± 0.56). In addition, with the analysis of fluorescence and circular dichroism spectroscopy, the spatial structures of myofibrillar protein (MP) in salted meat were obviously changed by PNE. Meanwhile, methylconiferin, 1-O-feruloyl-ß-D-glucose, nortrachelogenin, secoxyloganin, 1-O-(4-coumaroyl)-ß-D-glucose and pelargonidin-3-O-glucoside were identified from PNE. Furthermore, according to the analysis of molecular docking, hydrogen bond, hydrophobic force, and electrostatic force were obtained as the main molecular forces between MP and the phenolic compounds of PNE, while arginine, glutamic acid, and glycine residues were the main binding sites. All results suggested that PNE might be a potential candidate to improve the quality of salted meat in the food industry. PRACTICAL APPLICATION: The quality deterioration of meat may not only affect its further processing and consumption but also may lead to some food safety problems. In present study, PNE exhibited the fine capability to inhibit the oxidation of meat, while it could ameliorate the texture, color, and physicochemical properties of meat due to its tightly interaction with myofibrillar protein. All result suggested that PNE could be potentially utilized to improve the quality of meat in food industry.

Allergenic components, biocides, and analysis techniques of some essential oils used in food products.

Nowadays, almost 300 essential oils (EOs) are commonly traded in the world market, with a prediction to be worth over $14 billion in 2024. EOs are natural preservatives for food products in order to reduce the activity of pathogenic microorganisms, therefore their use as an antioxidant or a preservative in foods has been encouraged. They are not only considered as antimicrobial or flavoring agents, but are also incorporated into food packaging materials. There are several types of EOs which have been approved as food additives by the Food and Drug Administration. Hence, it is important to use safe EO products to minimize possible adverse effect risks such as nausea, vomiting, necrosis, nephropathy, mucous membrane, and skin irritation. This review article gives information about some EOs that are used in the food industries and the types of some allergenic compounds and biocides which could make the EOs hazardous or may cause allergenic reactions in the human body. Besides, some analysis techniques of possible allergenic compounds or biocides in EOs were introduced and supported with the most relevant studies. The overall conclusion from the study is that pregnant women, patients taking drugs (e.g., diabetics) or the having a history of allergy are the most prone to be affected from EO allergenic components. As regards to biocides, organochlorine and organophosphorus types of pesticides that are carried over from the plant may be found mostly in EOs. The most common allergic reaction is skin sensitization and irritation if the EO components are oxidized during storage or transportation. Moreover, drug interactions are one of the other possible adverse effect. Hence, determination of biocides and possible allergenic component concentrations is an essential factor when they are used as a preservative or flavoring agent. The most prominent analysis techniques are gas and liquid chromatography because most of the allergens and biocides are mainly composed of volatile components. PRACTICAL APPLICATION: Determining of the essential oil's content will be crucial if oils are used for food preservation or flavoring because they may have some hazardous effects, such as nausea, vomiting, necrosis and nephropathy. Therefore, after applying them to the food products, consumers (especially pregnant women) should be informed about their concentration levels and their possible adverse effects are taken into account when they are consumed over toxic limit. For this reason, we reviewed in our study that some allergenic components, biocides and toxic limits of EOs to be used in food products. In addition to this, recent analytical techniques have been explained and discussed which methods are suitable for analysis.

Antimicrobial Effect of Tea Polyphenols against Foodborne Pathogens: A Review.

ABSTRACT: Food contamination by foodborne pathogens is still widespread in many countries around the world, and food safety is a major global public health issue. Therefore, novel preservatives that can guarantee safer food are in high demand. Contrary to artificial food preservatives, tea polyphenols (TPs) are getting wide attention as food additives for being "green," "safe," and "healthy." TPs come from many sources, and the purification technology is sophisticated. Compared with other natural antibacterial agents, the antibacterial effect of TPs is more stable, making them excellent natural antibacterial agents. This review includes a systematic summary of the important chemical components of TPs and the antibacterial mechanisms of TPs against various foodborne pathogens. The potential applications of TPs are also discussed. These data provide a theoretical basis for the in-depth study of TPs.

Synergistic Effect of Mandarin Peels and Hesperidin with Sodium Nitrite against Some Food Pathogen Microbes.

Food preservatives such as NaNO2, which are widely used in human food products, undoubtedly affect, to some extent, human organs and health. For this reason, there is a need to reduce the hazards of these chemical preservatives, by replacing them with safe natural bio-preservatives, or adding them to synthetic ones, which provides synergistic and additive effects. The Citrus genus provides a rich source of such bio-preservatives, in addition to the availability of the genus and the low price of citrus fruit crops. In this study, we identify the most abundant flavonoids in citrus fruits (hesperidin) from the polar extract of mandarin peels (agro-waste) by using spectroscopic techniques, as well as limonene from the non-polar portion using GC techniques. Then, we explore the synergistic and additive effects of hesperidin from total mandarin extract with widely used NaNO2 to create a chemical preservative in food products. The results are promising and show a significant synergistic and additive activity. The combination of mandarin peel extract with NaNO2 had synergistic antibacterial activity against B. cereus, Staph. aureus, E. coli, and P. aeruginosa, while hesperidin showed a synergistic effect against B. cereus and P. aeruginosa and an additive effect against Staph. aureus and E. coli. These results refer to the ability of reducing the concentration of NaNO2 and replacing it with a safe natural bio-preservative such as hesperidin from total mandarin extract. Moreover, this led to gaining benefits from their biological and nutritive values.