Effect of gelatin coating incorporated with cinnamon oil on the quality of fresh rainbow trout in cold storage

Advances in the concept of functional foods and feeds: applications of cinnamon and turmeric as functional enrichment ingredients

Spices are a rich source of vitamins, polyphenols, proteins, dietary fiber, and minerals such as calcium, magnesium, iron, and zinc, all of which play an important role in biological functions. Since ancient times, spices have been used in our kitchen as a food coloring agent. Spices like cinnamon and turmeric allegedly contain various functional ingredients, such as phenolic and volatile compounds. Therefore, this review aims to summarize the current knowledge about the nutritional profiles of cinnamon and turmeric, as well as to analyze the clinical studies on their extracts and essential oils in animals and humans. Furthermore, their enrichment applications for food products and animal feed have also been investigated in terms of safety and toxicity. Numerous studies have shown that cinnamon and turmeric have various health benefits, including the reduction of insulin resistance and insulin signaling pathways in diabetic patients, the reduction of inflammatory biomarkers, and the maintenance of gut microflora in both animals and humans. The food and animal feed industries have taken notice of these health benefits and have begun to promote cinnamon and turmeric as healthy foods. This has resulted in the development of new food products and animal feeds that contain cinnamon and turmeric as primary ingredients, which have been deemed an effective means of promoting cinnamon and turmeric's health benefits.

Changes in Lipids and Proteins of Common Carp (Cyprinus carpio) Fillets under Frozen Storage and Establishment of a Radial Basis Function Neural Network (RBFNN)

Storage via freezing remains the most effective approach for fish preservation. However, lipid oxidation and protein denaturation still occur during storage, along with nutritional loss. The extent of lipid alteration and protein denaturation are associated with human health defects. To precisely predict common carp (Cyprinus carpio) nutritional quality change during frozen storage, here, we first determined lipid oxidation and hydrolysis and protein denaturation of common carp fillets during 17 weeks of frozen preservation at 261 K, 253 K, and 245 K. Results showed that the content of thiobarbituric acid reactive substances (TBARS) and free fatty acids (FFA) were significantly increased. However, salt-soluble protein (SSP) content, Ca²⁺-ATPase activity, and total sulfhydryl (SH) content kept decreasing during frozen storage, with SSP content decreasing by 64.82%, 38.14%, and 11.24%, respectively, Ca²⁺-ATP enzyme activity decreasing to 12.50%, 18.52%, and 28.57% Piμmol/mg/min, and SH values decreasing by 70.71%, 64.92%, and 56.51% at 261 K, 253 K, and 245 K, respectively. The values at 261 K decreased more than that at 253 K and 245 K (p < 0.05). Ca²⁺-ATPase activity was positively correlated (r = 0.96) with SH content. Afterwards, based on the results of the above chemical experiments, we developed a radial basis function neural network (RBFNN) to predict the modification of lipid and protein of common carp fillets during frozen storage. Results showed that all the relative errors of experimental and predicted values were within ±10%. In summary, the quality of common carp can be well protected at 245 K, and the established RBFNN could effectively predict the quality of the common carp under frozen conditions at 261-245 K.

A Review of Regulatory Standards and Advances in Essential Oils as Antimicrobials in Foods

As essential oils (EOs) possess GRAS status, there is a strong interest in their application to food preservation. Trends in the food industry suggest consumers are drawn to environmentally friendly alternatives and less synthetic chemical preservatives. Although the use of EOs has increased over the years, adverse effects have limited their use. This review aims to address the regulatory standards for EO usage in food, techniques for delivery of EOs, essential oils commonly used to control pathogens and molds, and advances with new active compounds that overcome sensory effects for meat products, fresh fruits and vegetables, fruit and vegetable juices, seafood, dairy products, and other products. This review will show adverse sensory effects can be overcome in various products by the use of edible coatings containing encapsulated EOs to facilitate the controlled release of EOs. Depending on the method of cooking, the food product has been shown to mask flavors associated with EOs. In addition, using active packaging materials can decrease the diffusion rate of the EOs, thus controlling undesirable flavor characteristics while still preserving or prolonging the shelf life of food. The use of encapsulation in packaging film can control the release of volatile or active ingredients. Further, use of EOs in the vapor phase allows for contact indirectly, and use of nanoemulsion, coating, and film wrap allows for the controlled release of the EOs. Research has also shown that combining EOs can prevent adverse sensory effects. Essential oils continue to serve as a very beneficial way of controlling undesirable microorganisms in food systems.

Edible Coatings Based on a Furcellaran and Gelatin Extract with Herb Addition as an Active Packaging for Carp Fillets

This is the first such study in which a gelatin extract obtained from carp skins enriched with dry herbs (thyme or rosemary) has been prepared. Extracts prepared in such a manner were added to furcellaran coatings. Coatings were tested for their mechanical properties and the obtained results showed that the control coatings, and those with the addition of rosemary, had the best strength-related parameters. A new ready-to-cook product was evaluated with regard to the preservative effects of carp skin gelatin coatings containing rosemary and thyme extracts in terms of pH, biogenic amine formulation, microbial changes and sensorial characteristics. The coatings with added rosemary proved effective in inhibiting the formation of biogenic amines, and slowing down the microbial deterioration of carp fillets (reduction by 0.53 and 0.29 log cfu/g). The evaluated herb coatings changed the characteristic taste of fish. Interestingly, the coatings emphasized the natural saltiness of fish meat.

Application of antimicrobial, potential hazard and mitigation plans

The tremendous rise in the consumption of antimicrobial products had aroused global concerns, especially in the midst of pandemic COVID-19. Antimicrobial resistance has been accelerated by widespread usage of antimicrobial products in response to the COVID-19 pandemic. Furthermore, the widespread use of antimicrobial products releases biohazardous substances into the environment, endangering the ecology and ecosystem. Therefore, several strategies or measurements are needed to tackle this problem. In this review, types of antimicrobial available, emerging nanotechnology in antimicrobial production and their advanced application have been discussed. The problem of antimicrobial resistance (AMR) due to antibiotic-resistant bacteria (ARB)and antimicrobial resistance genes (AMG) had become the biggest threat to public health. To deal with this problem, an in-depth discussion of the challenges faced in antimicrobial mitigations and potential alternatives was reviewed.

Development of active edible coatings based on fish gelatin enriched with Moringa oleifera extract: Application in fish (Mustelus mustelus) fillet preservation

An edible coating was developed using gelatin extracted from the skin of gray triggerfish (Balistes capriscus) and applied to the fillet of the smooth-hound shark (Mustelus mustelus). Moringa oleifera leaf extract was added to gelatin coating solution to improve its preservative properties. The phenolic profiles and antioxidant and antibacterial activities of M. oleifera extracts were determined. Phenolic acids constituted the largest group representing more than 77% of the total compounds identified in the ethanol/water (MOE/W) extract, among which the quinic acid was found to be the major one (31.48 mg/g extract). The MOE/W extract presented the highest DPPH• scavenging activity (IC50 = 0.53 ± 0.02 mg/ml) and reducing (Fe3+) power (EC0.5 = 0.57 ± 0.02 mg/ml), as well as interesting inhibition zones (20-35 mm) for the most tested strains. Coating by 3% of gelatin solution significantly reduced most deterioration indices during chilled storage, such as malondialdehyde (MDA), total volatile basic nitrogen (TVB-N), weight loss, pH, and mesophilic, psychrophilic, lactic, and H2S-producing bacterial counts. Interestingly, coating with gelatin solution containing MOE/W extract at 20 μg/ml was more effective than gelatin applied alone. Compared with the uncoated sample, gelatin-MOE/W coating reduced the weight loss and MDA content by 26% and 70% after 6 days of storage, respectively. Texture analysis showed that the strength of uncoated fillet increased by 46%, while the strength of fillet coated with gelatin-MOE/W only increased by 12% after 6 days of storage. Fish fillet coated with gelatin-MOE/W had the highest sensory scores in terms of odor, color, and overall acceptability throughout the study period.

Potential of nanochitosan coating combined with walnut green husk to improve the preservation of rainbow trout (Oncorhynchus mykiss) during refrigerated storage

The present study evaluated the potential of nanochitosan coating enriched with ethanol-water extract of the walnut green husk (WGHE) on spoilage and rancidity of rainbow trout (Oncorhynchus mykiss) during six-day refrigerated storage. Hence, we have considered fresh trout fillets without any treatment as control (C), immersed in 2% solution of chitosan nanoparticles (CN), combination with 1.5% and 3% WGHE with nanochitosan coating (CN + WGHE 1.5 and CN + WGHE3), for physicochemical, microbial and sensorial assays. The highest levels and total volatile nitrogen were observed after day 6 in C, while the lowest was found in CN + WGHE3 groups. Thiobarbituric acid reactive substance (TBARS) and peroxide value of untreated fillets on day 6 of the study were significantly higher than NC + WGHE3 with 0.08 mg/g and 3.27 mEq/kg, respectively. The total microbial population was: C ˃ CN ˃ CN + WGHE 1.5 > CN + WGHE3, which expresses the effect of the extract on the total microbial population. Overall, the combination of WGHE with CN increased the extract's efficiency in reducing peroxide value, TBARS, and total volatile nitrogen and delayed the pH increase, improving the overall acceptability of rainbow trout fillets stored in refrigerated conditions.

Antimicrobial and Antioxidant Effects of Kappa-Carrageenan Coatings Enriched with Cinnamon Essential Oil in Pork Meat

Fresh pork is susceptible to microbial contamination and lipid oxidation, which leads to food safety and quality issues. This study aimed to develop a kappa-carrageenan (KC) coating embedded with cinnamon essential oil (CEO) for antimicrobial and antioxidant purposes in pork meat. The uncoated controls and coated samples were subjected to microbial (total viable count, lactic acid bacteria, and H2S-producing bacteria), chemical (DPPH and pH), and physical (surface color) analyses during refrigerated storage at 4 °C for 7 days. It was observed that KC coatings exhibited a better preservation effect on pork meat after the addition of CEO. The KC−CEO coatings were effective in retarding the growth of total viable count, lactic acid bacteria, and H2S-producing bacteria. In a DPPH test, the level of lipid oxidation in pork meat was also significantly (p < 0.05) reduced by the KC−CEO coatings. Furthermore, these coatings displayed pronounced activity in inhibiting the adverse alterations of pH value and surface color. Practically, KC−CEO-coated samples still exhibited an attractive bright red color at the end of refrigerated storage. Taken together, the developed KC−CEO coatings exerted pronounced antimicrobial and antioxidant activities in pork, thus providing a potential approach to preserving perishable meat.

A Comprehensive Review of Biodegradable Polymer-Based Films and Coatings and Their Food Packaging Applications

Food sectors are facing issues as a result of food scarcity, which is exacerbated by rising populations and demand for food. Food is ordinarily wrapped and packaged using petroleum-based plastics such as polyethylene, polyvinyl chloride, and others. However, the excessive use of these polymers has environmental and health risks. As a result, much research is currently focused on the use of bio-based materials for food packaging. Biodegradable polymers that are compatible with food products are used to make edible packaging materials. These can be ingested with food and provide consumers with additional health benefits. Recent research has shifted its focus to multilayer coatings and films-based food packaging, which can provide a material with additional distinct features. The aim of this review article is to investigate the properties and applications of several bio-based polymers in food packaging. The several types of edible film and coating production technologies are also covered separately. Furthermore, the use of edible films and coatings in the food industry has been examined, and their advantages over traditional materials are also discussed.

Horseradish peroxidase catalyzed grafting of chitosan oligosaccharide with different flavonols: structures, antioxidant activity and edible coating application

BACKGROUND

Enzymatic catalyzed grafting of oligosaccharides with polyphenols is a safe and environmentally friendly approach to simultaneously enhance the bioactivity of oligosaccharides and the solubility of polyphenols. In this study, chitosan oligosaccharide (COS) was grafted with three different flavonols including myricetin (MYR), quercetin (QUE) and kaempferol (KAE) by horseradish peroxidase (HRP) catalysis. The structures, antioxidant activity and edible coating application of COS-flavonol conjugates were investigated.

RESULTS

The total phenol content of COS-MYR, COS-QUE and COS-KAE conjugates was 59.89, 68.37 and 53.77 mg gallic acid equivalents g^-1 , respectively. Thin layer chromatography showed the conjugates did not contain ungrafted flavonols. COS-flavonol conjugates showed ultraviolet absorption peak at about 294 nm, corresponding to the A-ring of flavonols. Fourier-transform infrared spectra of conjugates confirmed the formation of Schiff-base and Michael-addition products. The proton-nuclear magnetic resonance spectrum of COS-KAE conjugate exhibited phenyl proton signals of KAE. X-ray diffraction patterns of conjugates showed some diffraction peaks of flavonols. COS-flavonol conjugates presented rough and porous morphologies with sheet-like and/or blocky structures. The conjugates showed higher water solubility, free radical scavenging activity and reducing power than flavonols. Moreover, fish gelatin/COS-flavonol conjugate coatings effectively prolonged the shelf life of refrigerated largemouth bass (Micropterus salmoides) fillets from 5 days to 7-8 days.

CONCLUSION

COS-flavonol conjugates prepared by HRP catalysis have great potentials as novel antioxidant agents. © 2022 Society of Chemical Industry.

Peppermint essential oil-loaded solid lipid nanoparticle in gelatin coating: Characterization and antibacterial activity against foodborne pathogen inoculated on rainbow trout (Oncorhynchus mykiss) fillet during refrigerated storage

The present study was conducted to determine the characterization and antibacterial activity of peppermint essential oil-loaded solid lipid nanoparticle (PEO-SLN) and its impact on the quality of trout fillet stored at 4 ± 1°C for 12 days. The SLNs were prepared through a bath sonication technique. PEO-SLNs contained 0.2% (w/v) PEO in 2% of lipid phase glycerol monostearate (GMS) and tween 80 (1% w/v) used as a surfactant in the aqueous phase. The characterization parameter of PEO-SLN was evaluated, and the antibacterial activity of PEO-SLNs was conducted under in vitro conditions. Trout samples were analyzed for inoculated Pseudomonas aeruginosa, Listeria monocytogenes, and Escherichia coli O157:H7 during refrigerated storage. The mean particle size of PEO-SLNs was 154.83 ± 1.21 nm with a polydispersity index (PDI) of 0.35 ± 0.01 and zeta potential was about -24.16 ± 0.51 mV. The results indicated that PEO-SLN had higher antibacterial activity than the free form of PEO and also when used in combination with gelatin coating (gel + PEO-SLN) had a significant effect on preventing microbial growth in trout fillets (p < 0.05). The most decreasing rate of P. aeruginosa (1.92 log CFU/g), E. coli O157:H7 (0.71 log CFU/g), and L. monocytogenes count (1.69 log CFU/g) was seen in gel + PEO-SLN. These findings illustrated that PEO-SLNs could potentially be utilized in the food industry to increase the shelf life of fish fillets.

Impacts of Nano-Gelatin Coating Containing Thymol and Nisin on Chemical Quality Indices of Rainbow Trout Fillets Stored at 4°C

Background: Seafood such as fish is an integral part of human nutrition and an excellent source of protein. However, their short shelf life is quite challenging for the food industry. Objectives: This study was carried out to investigate the effects of nano-gelatin coating embedded with thymol and nisin on the chemical quality indices of rainbow trout fillets during 16 days of storage at 4°C. Methods: The fillets were randomly divided into six groups, including control (C), gelatin (G), nano-gelatin (NG), nano-gelatin + thymol (NG-T), nano-gelatin + nisin (NG-N), and nano-gelatin + nisin and thymol (NG-T-N). The chemical quality of fish samples was assessed by performing pH, thiobarbituric acid reactive substance (TBARS), peroxide value (PV), free fatty acid (FFA), and total volatile basic nitrogen (TVB-N) analyses every four days. Results: The results revealed the stunning effect of nisin and thymol addition to the nano-gelatin coating on all chemical quality indices. Besides, PV, TBARS, and FFA analyses showed that nano-gelatin containing thymol significantly decreased lipid oxidation in fish fillet samples (P < 0.05). The lowest amounts of PV (8.33 meq oxygen/kg oil), TBARS, and FFA were recorded for NG-T-N. The best results in the TBARS test (P < 0.05) were observed in NG-T-N, followed by NG-T (1.45 and 1.69 mg of malonaldehyde/kg of tissue, respectively), and similar results were recorded for FFA analysis. On day 16, the lowest amounts of TVB-N were measured for NG-T-N, followed by NG-N and NG-T (26.13, 29.86, and 38.26 mg N/100 g, respectively). Both nisin and thymol reduced the TVB-N and increased the shelf life, and the best results were observed in groups treated with nisin and thymol simultaneously. However, the application of gelatin and nano-gelatin coating without nisin and thymol was ineffective in improving the chemical quality of samples, and they must be used with nisin and/or thymol. Conclusions: Gelatin nanogel embedded with thymol and nisin can be utilized to enhance the chemical quality and shelf life of fish fillets.

Influence of Essential Oils on the Microbiological Quality of Fish Meat during Storage

Simple Summary

Fish meat is highly perishable due to its composition and the naturally present microbiota. The food industry aims to provide healthy, safe, and high-quality products to the market. Several strategies, including the use of natural preservatives, may be used to enhance food shelf life, and they can also be combined with others, such as vacuum packaging. This being the case, essential oils are natural plant components that, due to their composition, possess high antimicrobial and antioxidant effects, and are therefore good candidates to be tested as fish preservatives together with vacuum packaging. In the present study, essential oils from Citrus lemon and Cinnamomum camphora were added to rainbow trout meat for evaluating the microbiological quality (counts of bacteria and identification of present microbiota) of the fish when vacuum packed and stored for 7 days at 4 °C. Our results show that lemon (0.5% and 1%) as well as C. camphora essential oils (0.5% and 1%) had a positive effect on the microbiological quality of fish meat, keeping a high microbial quality of the fish fillets during 7 days of cold storage. The use of these essential oils in combination with vacuum packaging is beneficial in extending the shelf life of rainbow trout meat. All isolated species under the tested conditions are identified in the present study; such information will be useful for the future development of preservation methodologies that target isolated microorganisms, which will enable the food industry to enhance the shelf life and safety of fish.

Abstract

The aim of the present study was to evaluate the microbiological quality of rainbow trout meat treated with essential oils (EOs from Citrus limon and Cinnamomum camphora) at concentrations of 0.5% and 1.0% in combination with vacuum packaging during storage. The composition of the EOs were analyzed by gas chromatography coupled with mass spectrometry, and total viable counts (TVCs), coliform bacteria (CB), and lactic acid bacteria (LAB) were determined on the zeroth, first, third, fifth, and seventh days of storage at 4 °C. Individual species of isolated microorganisms were identified using a MALDI-TOF MS Biotyper. The results show that the major components of the EOs were linalool (98.1%) in C. camphora and α-limonene in C. limon. The highest number of TVCs and CB were 4.49 log CFU/g and 2.65 log CFU/g in aerobically packed samples at the seventh day. The lowest TVCs were those of samples treated with 1% C. camphora EO. For CB the most effective treatment was 1% lemon EO. LAB were only detected in a few samples, and were never present in aerobically packed samples; the highest number of LAB was 1.39 log CFU/g in samples treated with 1% lemon EO at day seven. The most commonly isolated coliform bacteria were Hafnia alvei, Serratia fonticola, Serratia proteamaculans, Pantoea agglomerans, and Yersinia ruckeri. Lactobacillus sakei, Staphylococcus hominis, and Carnobacterium maltaromaticum were the most frequently isolated bacteria from lactic acid bacteria. In conclusion, C. camphora EO at a concentration of 1% showed the highest antimicrobial activity.

Combining Knowledge- and Data-Driven Fuzzy Approach to Evaluate Shelf-Life of Various Seafood Products

Due to the complexity of the deterioration process of seafood products, relying on one indicator is not adequate to determine the quality of such products. Usually, shelf-life was estimated based on various indicators complicating the decision-making process. Decision Support Systems are considered as a good solution. The current study aims to establish a simple and novel fuzzy model based on a combination of knowledge- and data-driven approaches to define a fuzzy quality deterioration index (FQDI) in various seafood products (rainbow trout, threadfin bream, and white shrimp samples) during cold storage. Total volatile basic nitrogen (TVB-N) and psychrotrophic microorganisms counts (PMCs) were determined based on traditional methods. The sensory analysis was performed by a data-driven fuzzy approach. Overall, the shelf-life of the rainbow trout fillet was estimated to be 8 days, based on all the freshness parameters. However, the shelf-life of the Japanese threadfin bream fillet was 5–7 days according to the microbial and chemical parameters, respectively. This time for shrimp samples was 6–8 days using sensory score and TVB-N contents. The results of data-driven fuzzy approach showed all of the quality properties were considered as the ‘Important’–‘Very Important’ (defuzzification score &gt;75). The TVB-N and PMCs were the most and weakest freshness quality properties (defuzzified-values: 84.64 and 78.75, respectively). Based on FQDI, the shelf-life of the rainbow trout, Japanese threadfin bream, and shrimp samples were estimated to be 8, 5, and 7 days, respectively. This method was able to successfully provide a comprehensive deterioration index for evaluating the seafood shelf-life. Such a total index can be considered as a comprehensive output (y variable) to predict seafood freshness by rapid and nondestructive method.

Recent Developments in Seafood Packaging Technologies

Seafood products are highly perishable, owing to their high water activity, close to neutral pH, and high content of unsaturated lipids and non-protein nitrogenous compounds. Thus, such products require immediate processing and/or packaging to retain their safety and quality. At the same time, consumers prefer fresh, minimally processed seafood products that maintain their initial quality properties. The present article aims to review the literature over the past decade on: (i) innovative, individual packaging technologies applied to extend the shelf life of fish and fishery products, (ii) the most common combinations of the above technologies applied as multiple hurdles to maximize the shelf life of seafood products, and (iii) the respective food packaging legislation. Packaging technologies covered include: Modified atmosphere packaging; vacuum packaging; vacuum skin packaging; active food packaging, including oxygen scavengers; carbon dioxide emitters; moisture regulators; antioxidant and antimicrobial packaging; intelligent packaging, including freshness indicators; time–temperature indicators and leakage indicators; retort pouch processing and edible films; coatings/biodegradable packaging, used individually or in combination for maximum preservation potential.

Natural bioactive substances for the control of food-borne viruses and contaminants in food

Abstract

Food-borne viruses and contaminants, as an important global food safety problem, are caused by chemical, microbiological, zoonotic, and other risk factors that represent a health hazard. Natural bioactive substances, originating from plants, animals, or microorganisms, might offer the possibility of preventing and controlling food-borne diseases. In this contribution, the common bioactive substances such as polyphenols, essential oils, proteins, and polysaccharides which are effective in the prevention and treatment of food-borne viruses and contaminants are discussed. Meanwhile, the preventive effects of natural bioactive substances and the possible mechanisms involved in food protection are discussed and detailed. The application and potential effects of natural bioactive substances in the adjuvant treatment for food-borne diseases is also described.

Graphical abstract

Chitosan-Based Coatings Incorporated with Cinnamon and Tea Extracts to Extend the Fish Fillets Shelf Life: Validation by FTIR Spectroscopy Technique

The aim of this study was to evaluate the effect of active coatings prepared from the chitosan on the quality parameters of fish fillets. Antimicrobial and antioxidant properties were improved by addition of tea and cinnamon extracts. Different quality parameters including free fatty acids (FFA), thiobarbituric acid value (TBA), trimethylamine (TMA), total volatile basic nitrogen (TVBN), whiteness, and pH of coated and noncoated samples were evaluated during storage for 20 d at 5 ± 1°C. Moreover, FTIR characterization (i.e., wavenumber and absorbance values) was used to investigate the oxidative stability. Extracts addition to chitosan coating had noticeable influence on reducing FFA and TBA. Moreover, modified chitosan coating decreased TVBN and TMA significantly. Based on FTIR finding, control sample showed the highest oxidation value, while the treated samples with chitosan\incorporated with tea and cinnamon extracts (CTCECS) had the lowest oxidation. The results showed that FTIR technique could be successfully applied to monitor the lipid oxidation of fish fillet. Therefore, FTIR provides a fast approach to study the compositional changes of food products rather than conventional chemical analysis. The findings of our research showed that chitosan coating modified with tea and cinnamon extracts could be used as a novel active packaging to prolong the shelf life quality of fish fillet.

Influence of anise (Pimpinella anisum L.) essential oil on the microbial, chemical, and sensory properties of chicken fillets wrapped with gelatin film

The present study aimed to develop a novel active edible film based on gelatin incorporated with 0, 0.3, 0.6, and 0.9% w/w anise essential oil as a natural preservative and investigate the shelf life extension potential of chicken fillets during 12 days of refrigerated storage. The chicken fillets were wrapped with the essence-free and anise essential oil-loaded gelatin films, and microbial counts, chemical and sensory tests were surveyed during chilled storage. Results showed that aerobic mesophilic bacteria and Pseudomonas spp counts significantly decreased at all levels of anise essential oil during the first week of storage, while psychrotrophs, yeasts, and molds numbers began to reduce at concentrations of 0.6 and 0.9% from day 6. The using of anise essential oil caused a significant decrease of chemical parameters of chicken fillets, and the values of pH, peroxide, thiobarbituric acid reactive substance, and total volatile basic-nitrogen reached from 7.42, 5.7 meq/kg, 2.21 mg malondialdehyde/kg, and 24.94 mg N/100 g for the essence-free wrapped samples to 4.8, 6.35 meq/kg, 1.73 mg malondialdehyde/kg, and 18.78 mg N/100 g for the ones wrapped with 0.9% anise essential oil-loaded gelatin films at the end of storage day. In conclusion, application of gelatin films loaded with 0.6 and 0.9% anise essential oil can be advised for wrapping chicken fillets to prolong the shelf life for at least one week.

Effects of cinnamaldehyde combined with ultrahigh pressure treatment on the flavor of refrigerated Paralichthys olivaceus fillets

The combined effects of cinnamaldehyde (CA) and ultrahigh pressure (UP) treatment on the flavor of olive flounder (Paralichthys olivaceus) fillets during storage at 4 °C for 20 days were investigated. Changes in total viable count, trimethylamine, ATP-related compounds, free amino acids, TCA-soluble peptides, electronic nose (E-nose) analysis and sensory quality were measured. The results indicated that CA and UP treatment, especially CA combined with UP, significantly reduced undesirable flavor compounds including inosine, hypoxanthine, TMA, and bitter amino acids, and accumulated pleasant flavor compounds such as inosine monophosphate and umami-related amino acids. In addition, the combination of CA and UP was shown to be more effective for retarding protein degradation and microbial growth than CA or UP treatment alone. In accordance with the results of E-nose analysis and sensory evaluation, CA combined with UP treatment had great potential for improving the flavor quality of refrigerated flounder fillets and extending their storage life.

The combined effects of cinnamaldehyde (CA) and ultrahigh pressure (UP) treatment on the flavor of olive flounder (Paralichthys olivaceus) fillets during storage at 4 °C for 20 days were investigated.

Influence of chitosan nanoparticles and fennel essential oils (Foeniculum vulgare) on the shelf life of Huso huso fish fillets during the storage

Fish and fishery products are important parts of the human diet, but the microbial, chemical, and physical deteriorations limit their shelf life. Using the modified atmospheric packaging system and edible coatings is one of the main procedures to improve the shelf life of fish. In this research, the effect of chitosan nanoparticles (CNPs) loaded with fennel essential oils along with modified atmosphere packaging (MAP) system on chemical, microbial, and sensorial properties of Huso huso fish fillets during storage at fridge were evaluated. The results showed that coating fish fillets with CNPs and fennel EO significantly reduced the peroxide value, total volatile nitrogen, and thiobarbituric acid value compared with the control samples. Microbial analyses showed a lower number of mesophilic, psychotropic, pseudomonas, and lactic acid bacteria in coated fillets compared with control and MAP packaging. Fish fillets coated with CNPs and EO showed high acceptability in all sensorial attribute through the storage. It can be concluded that using CNPs and fennel EO along with MAP packaging can enhance the shelf life for H. huso fillets up to 18 days in the fridge.

Novel natural food preservatives and applications in seafood preservation: a review

Food preservative additives are natural or synthetic substances which delay degradation in foods caused by microbial growth, enzyme activity, and oxidation. Until recently, the use of synthetic additives in food was more common. However, synthetic additives have not been widely accepted by consumers in recent years due to their assumed adverse effects on their health. Therefore, the tendency of consumers to natural additives is increasing day-by-day. Seafood is an easily perishable food due to its chemical composition. Immediately after harvest, changes in odor, taste, and texture in fishery products can be noticed. For this reason, measures to protect the product must be taken immediately after harvest or catching. Various preservation methods have been developed. In addition to various technological methods, preservative additives are used in fresh or processed seafood as well as in other foods. This review focuses on novel natural preservatives from different sources such as plants, bacteria, fungi, animals and algae, and their use in seafood to protect quality and prolong shelf life. © 2018 Society of Chemical Industry.

Antilisterial activity of Cymbopogon citratus on crabsticks

Listeria monocytogenes is a gram positive, psychrotrophic, facultative anaerobic bacterium and it is the etiological agent of listeriosis, a severe foodborne disease of major public health concern. There is a rising concern about the cross-contamination of surimi-based products with L. monocytogenes during handling and storage. Lemon grass (Cymbopogon citratus) is known to exhibit strong antimicrobial activity against bacteria due to the presence of citral. The objectives of this research were: (i) to develop a water-based extraction procedure for the antimicrobial component(s) in lemon grass and (ii) to evaluate the antimicrobial effect of a concentrated water-based extract and commercial essential oil (EO) of lemon grass against L. innocua (ATCC 33090), a surrogate strain of L. monocytogenes, in vitro and on crabsticks. Briefly, antilisterial activity of concentrated extract and commercial EO of lemon grass was tested using the agar well diffusion technique. Crabsticks were subsequently inoculated with L. innocua to a final density of ca. 4 log cfu/g and then coated with 500 μl of either concentrated extract or 0.5% commercial EO and stored at 4 °C for up to 15 days. Samples were then subjected to microbiological analysis every 5 days to enumerate counts of Listeria. Following the agar well diffusion assay, inhibition zones with mean diameters of 18.3 and 21.0 mm were obtained with the concentrated extract and commercial EO respectively. The population of L. innocua in WBE-coated (4.2 log cfu/g) and 0.5% EO-coated (2.7 log cfu/g) samples were significantly lower (P < 0.05) after 15 days than their untreated control counterpart (5.2 log cfu/g). Lemon grass extract and essential oil have the potential to control growth of L. monocytogenes in seafood surimi products with minimal adverse effect on the organoleptic characteristics of the product and thus can possibly be used as a natural food preservative.

Effect of alginate/carboxyl methyl cellulose composite coating incorporated with clove essential oil on the quality of silver carp fillet and Escherichia coli O157:H7 inhibition during refrigerated storage

The effects of alginate/carboxyl methylcellulose composite coating incorporated with clove essential oil on quality of silver carp fillet chilled storage (4 + 1 °C) were examined over a period of 16 days. The control samples (c), alginate/carboxyl methylcellulose coating (C-A), alginate/carboxyl methylcellulose composite coating incorporated with clove essential oil (with different concentration 1 and 1.5 %) (C-A + CEO1 % and C-A + CEO 15 % respectively) were analyzed by bacteriological (total viable counts (TVC) and total psychrotrophic counts (TPC)), biochemical (Peroxide value (PV), free fatty acid (FFA), total volatile base nitrogen (TVB-N), and pH) and sensory characteristics. Also, the efficacy of these treatments was investigated in control of the population of Eschershia coli O157:H7 inoculated in silver carp fillet. According to the obtained results, C-A + CEO 1.5 % showed lowest (p < 0.05) and acceptable biochemical, bacteriological and sensory characteristics attributes up to 16 days storage at 4 °C compared to the others. Also, this treated sample was acceptable even at the end of the 16-day storage and it could reduce the population of E. coli O157:H7 below the acceptable level (<2) from day 4 until the end of the storage period. The results indicate Alginate/carboxyl methylcellulose composite coating with clove essential oil might be recommended as a preservative in the meat products.

Effect of edible chitosan/clove oil films and high-pressure processing on the microbiological shelf life of trout fillets

BACKGROUND

The inhibitory effect of chitosan films with clove oil (0-50 g kg(-1) ) was evaluated on a range of ten representative food spoilage and pathogenic bacteria.

RESULTS

The most sensitive bacteria to the films was Shewanella putrefaciens and the most resistant was Aeromonas hydrophila (inhibition was apparent only at 50 g kg(-1) clove essential oil (CEO)). Films with 20 g kg(-1) CEO inhibited nine of ten of the bacteria tested. Chitosan films with 20 g kg(-1) CEO were combined with high-pressure (HPP) processing as treatments for trout fillets, and changes in physicochemical parameters and microbial load were evaluated at 4 °C over 22 days of storage. The films reduced weight loss and water activity compared to fresh and treated samples (HPP and cooking). Results showed that microbial load (total aerobic mesophilic, lactic acid bacteria and total coliform) of the trout fillets covered with chitosan films was lower than that for HPP-treated samples, and similar to cooked samples, except for coliform counts.

CONCLUSION

The use of 20 g kg(-1) CEO-chitosan films showed a further improvement in the shelf-life of trout fillets when compared to that obtained with HPP and cooking treatment.

Effect of alginate coating enriched with 6-gingerol on the shelf life and quality changes of refrigerated red sea bream (Pagrosomus major) fillets

The study aimed to determine the shelf life and quality changes of red sea bream which is coated by using sodium alginate (SA) enriched with 6-gingerol (GR) during 20 days of refrigerated storage (4 ± 1 °C).

Antibacterial activity of cinnamaldehyde and clove oil: effect on selected foodborne pathogens in model food systems and watermelon juice

Natural additives for the control of microbial growth are in demand because consumers prefer them over synthetic ones. In the present investigation, the antibacterial activity of two natural preservatives, cinnamaldeyde and clove oil alone or in combinations was studied, and their potential as food preservative in model food systems and watermelon juice was evaluated. The cinnamaldehyde and clove essential oil showed minimum inhibitory concentration (MIC) at or below 5000 mg/l, and fractional inhibitory studies using both the oils showed synergistic effect. In artificially inoculated barley model food system and cabbage model food system, 2 MIC of oils was able to reduce the growth of the tested bacteria (more than 5 log) during 4 weeks storage at 37 °C, and similar reduction was also observed when combinations of oils were used at one eighth of MIC against Bacillus cereus and Yersinia enterocolitica, and one fourth of MIC against Staphylococcus aureus and Escherichia coli. Natural contaminants of watermelon juice were also reduced by the combination of one fourth of MIC of the oils, which was more effective than individual 2 MICs. These findings may be useful for food applications, but their effect on sensory quality of various foods need to be studied.