Phase inversion temperature-fabricated cinnamon oil nanoemulsion as a natural preservative for prolonging shelf-life of chilled Asian seabass (Lates calcarifer) fillets

Preparation, characterization, and coating effect of bio-active nano-emulsion based on combined plant essential oils on quality of grass carp fillets

This study aimed to develop a satisfactory essential oil (EO) nano-emulsion through high pressure microjet technology and explore its physiochemical properties and synergistic coating effects on grass carp fillets. The optimal conditions for oregano/litsea cubeba (6:4, wt%/wt%) nano-emulsion were shown to be 80 s high pressure microjet pretreatment time, 9000 lb per square inch pretreatment pressure, 6 % oil phase, and 3:2 Km (mass ratio of surfactant to co-surfactant). The obtained nano-emulsion exhibited 100.42 ± 0.96 nm oil diameter at 4 °C after 15-day storage, coupled with high stability after centrifugation, freeze-thaw and heating treatment. Compared with untreated samples at day 6 storage, the nano-emulsion-treated grass carp fillets exhibited improved textural properties, higher water-holding capacity (74.23 % ± 0.80 %), lower total volatile basic nitrogen (TVB-N, 13.46 ± 0.30 mg/100g)/thiobaric acid (TBA,0.43 ± 0.02 mgMDA/100g), and lower total viable spoilage bacteria count (4.98 ± 0.21 lgCFU/g). This study facilitates understanding the combined EOs nano-emulsion on improving the shelf life of grass carp fillets.

Histological biomarkers and microbiological parameters of an estuarine fish from the Brazilian Amazon coast as potential indicators of risk to human health

This study aimed to isolate and identify pathogenic bacteria in the intestinal tract, skin, and muscles of Sciades herzbergii; detect histopathological changes in the gill and liver; and use these biomarkers for the assessment of potential risks to human health. Fish were sampled during the rainy and dry seasons at two points in São Marcos Bay, Maranhão, Brazil: Ilha dos Caranguejos (IC) and Porto Grande (PG). Isolation and quantification were carried out using COLItest®. Colonies were subjected to identification and phenotypic investigation of antimicrobial resistance using Vitek®. Gill and liver samples were subjected to routine histological examination. The results indicated the presence of Klebsiella pneumoniae and Escherichia coli, the latter of which showed phenotypic resistance to norfloxacin and gentamicin. Fish caught at PG exhibited more extensive gill and liver damage than fish caught at IC. The findings suggest that histological changes in target organs of S. herzbergii may be influenced by infection with pathogenic bacteria.

Response surface methodology to optimize the sterilization process of slightly acidic electrolyzed water for Chinese shrimp (Fenneropenaeus chinensis) and to investigate its effect on shrimp quality

Chinese shrimps are popular among consumers for their delicious taste and high nutritional value, but they are highly susceptible to deterioration due to microbial contamination with degradation of texture, color and flavor. The aim of this study was to evaluate the effects of available chlorine concentration (ACC), processing time and material-liquid ratio on the bacterial inhibition rate of shrimp treated with slightly acidic electrolyzed water (SAEW). The effective parameters were optimized by response surface methodology to the optimal bactericidal conditions: ACC 88 mg/L, processing time 12 min, and material-liquid ratio 1:4. The actual bactericidal inhibition rate of shrimp under these conditions was 37.60 %. On this basis, the quality, color difference and textural changes of shrimp treated with SAEW, sodium hypochlorite and alkaline electrolytic water were compared and investigated during storage at 4 °C. The combined results showed that the SAEW treatment could extend the shelf-life by more than 2 d.

Green active coating from chitosan incorporated with spontaneous cinnamon oil nanoemulsion: Effects on dried shrimp quality and shelf life

Green active film from chitosan (C) incorporated with spontaneous emulsified cinnamon oil nanoemulsion (CONE; droplet size of 79.27 nm and polydispersity index of 0.27) was developed. The obtained chitosan film containing CONE (C + CONE) had tensile elongation and light protective effect higher than C film due to the incorporation of bioactive compounds from cinnamon oil as proven by Fourier Transform Infrared Spectroscopy. The effect of C + CONE as active edible coating on the physical, chemical, and microbiological properties of dried shrimp was then investigated. The quality of samples coated with C + CONE (DS + C + CONE) was compared to those coated with C (DS + C) and without coating (DS). In this study, C + CONE could enhance astaxanthin content and reduce lipid oxidation in dried shrimp. During 6 weeks of storage, C + CONE was found to be an effective antimicrobial coating that significantly inhibited growth of bacteria, delayed lipid oxidation and retarded the production of volatile amines in dried shrimp. DS + C + CONE had lower malonaldehyde equivalents (0.52 mg/kg oil), trimethylamine (11.74 mg/100 g), total volatile base nitrogen (84.33 mg/100 g) and total viable count (4.80 Log CFU/g), but had higher astaxanthin content (12.53 ± 0.12 μg/g) than DS and DS + C. The results suggested that the developed C + CONE coating has potential to be used as active coating for preserving food quality.

Recent developments in nanoemulsions against spoilage in cold-stored fish: A review

Nanoemulsion-based technology is developing rapidly in the food industry, especially in the design of delivery systems for bioactive compounds. This review presents an in-depth understanding of the composition, function, antibacterial mechanism and successful application of nanoemulsions as preservative agents against fish spoilage. The results showed that the inclusion of bioactive substances in the food-grade nanoemulsions encapsulation system could improve its stability, control its release, inhibit the microbial growth and reproduction through a variety of targets. These nanoemulsions can inhibit fish spoilage via reducing microbial load and retarding the oxidation of proteins and lipids, thereby maintaining quality attributes of fish. In addition, nanoemulsions could be coupled with vacuum package for enhancing microbial destruction, retaining nutritional value and extending the shelf-life of fish. Accordingly, nanoemulsions are suggested as a promising strategy to inhibit fish spoilage.

Technological strategies for the use of plant-derived compounds in the preservation of fish products

New approaches to reducing synthetic preservatives in the preservation of foods draw the attention of plant-derived bioactive compounds, especially for application in foods highly susceptible to spoilage, such as fish products. The review presents relevant data from procurement, application, and methodological research trends to investigate the potential effects of plant-derived bioactive compounds on shelf life extension in fish products. The systematization of data allowed observation that the different methods of extraction and application of bioactive plant compounds result in different effects, such as the reduction of lipid oxidation, antimicrobial effects, and maintenance of sensory characteristics, benefiting the extension of shelf life. In general, plant-derived bioactive compounds are an alternative for the preservation of fish products; however, approaches to the composition of the compounds can contribute to the optimization and efficiency of the process from a technical point of view and industrial viability.

Nanoemulsion-based approach to preserve muscle food: A review with current knowledge

Muscle foods are regarded as nutritionally dense foods while they are prone to spoilage by action of microorganism and oxidation. Recently, the consumer's preference is mostly toward minimally processed foods as well as preserved with natural preservatives. However, natural extract directly to the food matrix has several drawbacks. Hence development and applications of nanoemulsion has gained importance for the preservation of muscle foods to meet consumer requirements with enhanced food safety. Nanoemulsion utilizes natural extracts at much lower concentration with higher preservative abilities over original components. Nanoemulsions offer protection to the active component from degradation and ensure longer bioavailability. Novel techniques used for formulation of nanoemulsion provide stability to the emulsion with desirable qualities to improve their impacts. The application of nanoemulsion is known to enhance the preservative action of nanoemulsions by improving the microbial safety and oxidative stability in nanoform. This review provides recent updates on different methods used for formulation of nanoemulsions from different sources. Besides, successful application of nanoemulsion derived using natural agents for muscle food preservation and shelf life extension are reviewed. Thus, the application of nanoemulsion to extend shelf life and maintain quality is suggested for muscle foods.

Effect of Citrus aurantium juice as a disinfecting agent on quality and bacterial communities of striped catfish steaks stored at -20 °C

Sodium hypochlorite is generally used as a disinfectant in washing of freshwater fishes where the safety aspect of health is of concern. Although plant-based essential oils and synthetic chemical agents have been applied, they might contain toxic substances, are expensive and can cause undesirable quality. This research aims to fill the knowledge gap necessary to validate Citrus aurantium juice as a disinfecting agent for preserving striped catfish steaks at -20 °C for 28 days. Fifty (50) ppm sodium hypochlorite was used as a commercial disinfectant (control). The results showed that a negative color characteristic (higher a* and increased b*) was found in the control but not in striped catfish steaks immersed in C. aurantium juice (TM) on days 14 and 28. No significant differences were found in the peroxide value among the treatments on days 14 and 28 (P > 0.05). A lower accumulation of trichloroacetic acid soluble peptides was detected in TM but not in control, while total volatile basic nitrogen of all treatments was up to standard of fish quality during storage. Contrastingly, the total viable count of both treatments increased to >7.0 log CFU/g on day 28 which did not meet the edible limit of standard for freshwater fishes. The spoilage microbial community was observed on days 0 and 28 of storage which showed a decrease in relative abundance of Acinetobacter, Pseudomonas, Brochothrix, Lactococcus, Carnobacterium, Psychrobacter, and Vagococcus as found in TM on day 28, when compared to the control. Thus, these results implied that C. aurantium juice could replace sodium hypochlorite as an alternative disinfecting agent to control the microbiological spoilage and physico-chemical quality of striped catfish steaks.

Recent developments in industrial applications of nanoemulsions

Nanotechnology is being utilized in various industries to increase the quality, safety, shelf-life, and functional performance of commercial products. Nanoemulsions are thermodynamically unstable colloidal dispersions that consist of at least two immiscible liquids (typically oil and water), as well as various stabilizers (including emulsifiers, texture modifiers, ripening inhibitors, and weighting agents). They have unique properties that make them particularly suitable for some applications, including their small droplet size, high surface area, good physical stability, rapid digestibility, and high bioavailability. This article reviews recent developments in the formulation, fabrication, functional performance, and gastrointestinal fate of nanoemulsions suitable for use in the pharmaceutical, cosmetic, nutraceutical, and food industries, as well as providing an overview of regulatory and health concerns. Nanoemulsion-based delivery systems can enhance the water-dispersibility, stability, and bioavailability of hydrophobic bioactive compounds. Nevertheless, they must be carefully formulated to obtain the required functional attributes. In particular, the concentration, size, charge, and physical properties of the nano-droplets must be taken into consideration for each specific application. Before launching a nanoscale product onto the market, determination of physicochemical characteristics of nanoparticles and their potential health and environmental risks should be evaluated. In addition, legal, consumer, and economic factors must also be considered when creating these systems.

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.

Combined effects of ultrasound and slightly acidic electrolyzed water on quality of sea bass (Lateolabrax Japonicus) fillets during refrigerated storage

A novel technique for sea bass (Lateolabrax Japonicus) fillets by combining ultrasound (US) and slightly acidic electrolyzed water (SAEW) to inactivate bacteria and maintain quality was developed. Samples were treated with distilled water (DW), US, SAEW and ultrasound combined with slightly acidic electrolyzed water (US + SAEW) for 10 min, respectively. The results suggested that US + SAEW treatment could retard the increase of total viable counts (TVC), Pseudomonas bacteria counts and H2S-producing bacteria counts, which also inhibit the rise of total volatile basis nitrogen (TVB-N), thiobarbituric acid (TBA), pH and K value. In addition, compared with SAEW or US treatment alone, US + SAEW treatment had distinctly effects on inhibiting protein degradation and maintaining better sensory scores. Compared with DW group, the shelf life of sea bass treated with US + SAEW was increased for another 4 days. It indicated that the combined treatment of US and SAEW could be used to the preservation of sea bass.

A Systematic Review on Nanoencapsulation Natural Antimicrobials in Foods: In Vitro versus In Situ Evaluation, Mechanisms of Action and Implications on Physical-Chemical Quality

Natural antimicrobials (NA) have stood out in the last decade due to the growing demand for reducing chemical preservatives in food. Once solubility, stability, and changes in sensory attributes could limit their applications in foods, several studies were published suggesting micro-/nanoencapsulation to overcome such challenges. Thus, for our systematic review the Science Direct, Web of Science, Scopus, and Pub Med databases were chosen to recover papers published from 2010 to 2020. After reviewing all titles/abstracts and keywords for the full-text papers, key data were extracted and synthesized. The systematic review proposed to compare the antimicrobial efficacy between nanoencapsulated NA (nNA) and its free form in vitro and in situ studies, since although in vitro studies are often used in studies, they present characteristics and properties that are different from those found in foods; providing a comprehensive understanding of primary mechanisms of action of the nNA in foods; and analyzing the effects on quality parameters of foods. Essential oils and nanoemulsions (10.9-100 nm) have received significant attention and showed higher antimicrobial efficacy without sensory impairments compared to free NA. Regarding nNA mechanisms: (i) nanoencapsulation provides a slow-prolonged release to promote antimicrobial action over time, and (ii) prevents interactions with food constituents that in turn impair antimicrobial action. Besides in vitro antifungal and antibacterial, nNA also demonstrated antioxidant activity-potential to shelf life extension in food. However, of the studies involving nanoencapsulated natural antimicrobials used in this review, little attention was placed on proximate composition, sensory, and rheological evaluation. We encourage further in situ studies once data differ from in vitro assay, suggesting food matrix greatly influences NA mechanisms.

Combined Effect of High-Pressure Processing with Spice Extracts on Quality of Low-Salt Sausage during Refrigerated Storage

The study evaluated the combined effect of high-pressure processing (HPP) and spice extracts on low-salt sausages during refrigerated storage. Physicochemical and microbiological characteristics of the sausages were determined. HPP treatment increased the thiobarbituric acid reactive substances (TBARS) value and the carbonyl content of the samples (p < 0.05), which meant lipid and protein oxidation was accelerated. Adding clove and cinnamon extracts can retard the oxidation caused by HPP (p < 0.05). The pH of the sausages treated with both the spice extracts and HPP maintained a higher pH value during the storage (p > 0.05). Compared with the samples treated with HPP or with the spice extracts alone, the combined treatment observably inhibited the growth of spoilage bacteria (p < 0.05) and improved the microbial community. The results demonstrated that the use of clove and cinnamon extracts in conjunction with HPP improved the storage quality and prolonged the shelf-life of the low-salt sausages. Thus, the combined use of spice extracts and HPP can be developed as a promising way to preserve low-salt meat products.

Encapsulation of cinnamaldehyde: an insight on delivery systems and food applications

Cinnamaldehyde is an essential oil extracted from the leaves, bark, roots and flowers of cinnamon plants (genus Cinnamomum). Cinnamaldehyde has shown biological functions such as antioxidants, antimicrobials, anti-diabetic, anti-obesity and anti-cancer. However, poor solubility in water as well as molecular sensitivity to oxygen, light, and high temperature limit the direct application of cinnamaldehyde. Researchers are using different encapsulation techniques to maximize the potential biological functions of cinnamaldehyde. Different delivery systems such as liposomes, emulsions, biopolymer nanoparticles, complex coacervation, molecular inclusion, and spray drying have been developed for this purpose. The particle size and morphology, composition and physicochemical properties influence the performance of each delivery system. Consequently, the individual delivery system has its advantages and limitations for specific applications. Given the essential role of cinnamaldehyde in functional food and food preservation, appropriate approaches should be applied in the encapsulation and application of encapsulated cinnamaldehyde. This review systematically analyzes available encapsulation techniques for cinnamaldehyde in terms of their design, properties, advantages and limitations, and food application status. The information provided in this manuscript will assist in the development and widespread use of cinnamaldehyde-loaded particles in the food and beverage industries.

Anti-aging properties of phytoconstituents and phyto-nanoemulsions and their application in managing aging-related diseases

Aging is spontaneous and inevitable process in all living beings. It is a complex natural phenomenon that manifests as a gradual decline of physiological functions and homeostasis. Aging inevitably leads to age-associated injuries, diseases, and eventually death. The research on aging-associated diseases aimed at delaying, preventing or even reversing the aging process are of great significance for healthy aging and also for scientific progress. Numerous plant-derived compounds have anti-aging effects, but their therapeutic potential is limited due to their short shelf-life and low bioavailability. As the novel delivery system, nanoemulsion can effectively improve this defect. Nanoemulsions enhance the delivery of drugs to the target site, maintain the plasma concentration for a longer period, and minimize adverse reaction and side effects. This review describes the importance of nanoemulsions for the delivery of phyto-derived compounds and highlights the importance of nanoemulsions in the treatment of aging-related diseases. It also covers the methods of preparation, fate and safety of nanoemulsions, which will provide valuable information for the development of new strategies in treatment of aging-related diseases.

Natural antimicrobial-loaded nanoemulsions for the control of food spoilage/pathogenic microorganisms

Both consumers and producers of food products are looking for natural ingredients and efficient formulation strategies to improve the shelf life of final products. Natural antimicrobial ingredients such as essential oils can be applied as alternatives to synthetic preservatives, but their main challenge is low stability, adverse effects on sensory properties, low solubility, high needed doses, etc. Formulation of these bioactive compounds into nanoemulsions can be an efficient strategy to improve their properties and practical applications in food products. In this review, after an overview on nanoemulsion formulation, ingredients and fabrication methods, different types of natural antimicrobial agents have been discussed briefly. In addition, properties and action mechanisms of antimicrobial-loaded nanoemulsions, along with their application in preservation and shelf life improvement of different food products have been explained. Finally, safety and regulatory issues of antimicrobial delivery via nanoemulsions have been examined. As a conclusion antimicrobial-loaded nanoemulsions can be promising candidates and alternatives for common synthetic preservatives in real food systems.

Eugenol-chitosan nanoemulsion as an edible coating: Its impact on physicochemical, microbiological and sensorial properties of hairtail (Trichiurus haumela) during storage at 4 °C

Effects of the eugenol-chitosan nanoemulsion as an edible coating on the quality of hairtail (Trichiurus haumela) during storage at 4 °C were evaluated. For all samples, such parameters as pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), electrical conductivity (EC), total bacteria count (TVC) and sensory were examined periodically. The results demonstrated that eugenol-chitosan nanoemulsion coating showed better preservative effects than chitosan nanoemulsion alone. Therefore, a coating based on eugenol-chitosan nanoemulsion could be regarded as an effective food-grade biopreservative to maintain the quality of hairtail fish and prolong its shelf life during chilled storage.

Use of Spectroscopic Techniques to Monitor Changes in Food Quality during Application of Natural Preservatives: A Review

Consumer demand for food of high quality has driven research for alternative methods of food preservation on the one hand, and the development of new and rapid quality assessment techniques on the other hand. Recently, there has been a growing need and interest in healthier food products, which has led to an increased interest in natural preservatives, such as essential oils, plant extracts, and edible films and coatings. Several studies have shown the potential of using biopreservation, natural antimicrobials, and antioxidant agents in place of other processing and preservation techniques (e.g., thermal and non-thermal treatments, freezing, or synthetic chemicals). Changes in food quality induced by the application of natural preservatives have been commonly evaluated using a range of traditional methods, including microbiology, sensory, and physicochemical measurements. Several spectroscopic techniques have been proposed as promising alternatives to the traditional time-consuming and destructive methods. This review will provide an overview of recent studies and highlight the potential of spectroscopic techniques to evaluate quality changes in food products following the application of natural preservatives.

Synthesis and Technology of Nanoemulsion-Based Pesticide Formulation

Declines in crop yield due to pests and diseases require the development of safe, green and eco-friendly pesticide formulations. A major problem faced by the agricultural industry is the use of conventional agrochemicals that contribute broad-spectrum effects towards the environment and organisms. As a result of this issue, researchers are currently developing various pesticide formulations using different nanotechnology approaches. The progress and opportunities in developing nanoemulsions as carriers for plant protection or nanodelivery systems for agrochemicals in agricultural practice have been the subject of intense research. New unique chemical and biologic properties have resulted in a promising pesticide nanoformulations for crop protection. These innovations-particularly the nanoemulsion-based agrochemicals-are capable of enhancing the solubility of active ingredients, improving agrochemical bioavailability, and improving stability and wettability properties during the application, thus resulting in better efficacy for pest control and treatment. All of these-together with various preparation methods towards a greener and environmentally friendly agrochemicals-are also discussed and summarized in this review.