Effects of bactericides and modified atmosphere packaging on shelf-life of Chinese shrimp (Fenneropenaeus chinensis)

Evaluation of In Vitro Antioxidant, Anti-Obesity, and Anti-Diabetic Activities of Opuntia ficus Cladodes Gel and Its Application as a Preservative Coating for Shrimp during Refrigerated Storage

Opuntia ficus cladodes (OFC) are considered one of the wastes that result from opuntia cultivation, and their disposal by traditional methods results in many environmental problems. Therefore, this study was conducted with two aims. The first was the production of OFC gel, and the evaluation of its in vitro antioxidant (by two methods, DPPH and ABTS), anti-obesity, and anti-diabetic activities. The second was an investigation of the effects of different concentrations of this gel (0, 50, and 100%) as an edible coating on the quality of shrimp during 8 days of refrigerated storage. The results showed that this gel was characterised by a high content of ash (10.42%), total carbohydrates (75.17%), and total phenols (19.79 mg GAE/g). OFC gel contained six types of sugars: arabinose, xylose, galactose, rhamnose, glucose, and uronic acid, and the most abundant was xylose (36.72%). It is also clear from the results that the OFC gel had high antioxidant properties, which were higher against DPPH than ABTS at the same concentration. OFC gel showed a high inhibition activity against lipase, α-glycosidase, and α-amylase enzymes, and their IC50 values were 1.43 mg/mL, 0.78 mg/mL, and 0.57 mg/mL, respectively. The results also stated that shrimp coated with OFC gel had lower pH, drip loss, TVB-N, and TBA values through the days of refrigerated storage. Moreover, the shrimp coated with 100% OFC gel were better than those coated with 50% OFC gel. In conclusion, OFC gel showed high potency as active antioxidant, for its enzyme anti-activities, and as an edible coating for shrimp.

Studying the microbial, chemical, and sensory characteristics of shrimp coated with alginate sodium nanoparticles containing Zataria multiflora and Cuminum cyminum essential oils

Retardation of quality loss of seafood has been a new concept in recent years. This study's main objective was to evaluate the microbial, chemical, and sensory attributes of shrimp coated with alginate sodium nanoparticles containing Zataria multiflora and Cuminum cyminum essential oils (EOs) during refrigerated storage. At the end of storage time (15 days storage at 4°C), the pH, thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVBN) amounts in shrimps coated with the alginate nanoparticles were 7.62, 1.14 mg MDA/kg, and 117 mg/100 g which were significantly (p < .05) lower than the control groups. The count of all bacteria groups was also lower in this treatment, which was 2-2.74 Log CFU/mL on day 15 of cold storage. This combined treatment also obtained the highest sensory scores (around 7) and the lowest melanosis score (2.67) due to the effective delaying microbial and oxidation activities. Therefore, this edible coating could substantially retard microbial and chemical changes and improve the organoleptic properties of shrimp under refrigerated storage.

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.

Effects of chitosan combined with ε-polylysine coating on flavor and texture quality of Chinese shrimp during refrigerated storage

We investigated the effects of chitosan (CH) combined with ε‐polylysine (ε‐PL) on the flavor and texture quality of Chinese shrimp refrigerated for 12 days. Shrimp samples were subjected to three preservation treatments (ε‐PL, CH, and CH + ε‐PL) and a control treatment. Sensory characteristics, total volatile basic nitrogen (TVB‐N), adenosine triphosphate (ATP)‐related compounds, K‐values, volatile components, and texture were regularly assessed. The results showed that the sensory characteristics were effectively maintained, the increases in TVB‐N, hypoxanthine, and K‐value were delayed, and the putrid compounds were reduced by coating, especially with the chitosan combined with ε‐polylysine. Treatment with chitosan combined with ε‐polylysine was also shown to be a more effective preservation method for maintaining the texture quality of Chinese shrimp compared to treatment with ε‐PL or CH alone. Therefore, this technique was demonstrated to be a promising method for maintaining the flavor and texture quality of Chinese shrimp during refrigerated storage.

Effects of different thawing methods on physicochemical properties and structure of largemouth bass (Micropterus salmoides)

To evaluate the physicochemical properties and structure of thawed fillets, following six treatments were used: conventional thawing, microwave thawing, microwave or ultrasound combined with vacuum thawing, magnetic nanoparticles combined with microwave or far-infrared thawing. The thawing loss, cooking loss, pH, color, texture change, water-holding capacity, and water migration of fish fillets were determined. The total volatile base nitrogen and thiobarbituric acid were used to determine the degree of protein degradation and lipid oxidation. Microscope observations and scanning electron microscope (SEM) were used to observe fiber microstructure. Results indicated that both microwave combined with vacuum thawing and far-infrared combined with magnetic nanoparticles thawing had desirable physicochemical properties as compared to other thawing methods. The lower total volatile base nitrogen and thiobarbituric acid values had less effect on protein degradation and lipid oxidation of thawing process. Besides, both microwaves combined with vacuum thawing and far-infrared combined with magnetic nanoparticles thawing samples had no significant difference in immobilized and bond water compared with fresh sample. SEM and microscopic observation showed that the myofibril bundles were arranged regularly and smoothly in microwave combined with vacuum thawing and far-infrared combined with magnetic nanoparticles thawing samples compared with other thawed methods. Thus, the microwave combined with vacuum thawing and far-infrared combined with magnetic nanoparticles thawing as potential thawing methods could be used to maintain the quality of thawed fish fillets. PRACTICAL APPLICATION: Largemouth bass (Micropterus salmoides) is a good source of animal protein. The fish needs to be frozen for circulation because of geographical and seasonal factors, so thawing methods can directly affect the quality of thawed fish. The results showed that the microwave combined with vacuum and the magnetic nanoparticles combined with far-infrared thawing could better maintain the quality of thawed fish.

The combined effects of lactoperoxidase system and whey protein coating on microbial, chemical, textural, and sensory quality of shrimp (Penaeus merguiensis) during cold storage (4 ± 1°C)

Growth and reproduction of gram-negative bacteria has a pivotal role in spoilage of seafood products. In order to identify the effect of lactoperoxidase system (LPOS), an antimicrobial activity was added to whey protein solution at the levels of 0 (control group), 1.25%, 2.5%, 5%, and 7.5%. Then, the shrimp samples were coated with immersion method and stored in the refrigerator for 16 days. In this period, the microbial tests of psychrotrophic bacteria, mesophilic bacteria, Pseudomonas fluorescens, Pseudomonas spp., and Shewanella putrefaciens, chemical tests of total volatile basic nitrogen, thiobarbituric acid, and pH, and sensory evaluation were carried out on the days of 0, 4, 8, 12, and 16. Adding LPOS in the coating resulted in a decrease in the total specific spoilage organisms and TVB-N. There was no significant effect for the TBA test. The levels of LPOS showed a positive correlation with the acceptable measurement in the sensory evaluation.

The effects of vacuum and modified atmosphere packaging on quality changes in seasoned cobia (Rachycentron canadum) sticks stored under refrigeration

Abstract The objective of this research was to compare the quality attributes of seasoned cobia sticks packed under vacuum and using modified atmosphere packaging (MAP) and stored under refrigeration, as well as to establish the most suitable gas mixtures to maintain product freshness and provide an extended shelf life. The seasoned cobia sticks were breaded with a mixture of dehydrated spices (parsley, onion, garlic, tomato and bacon), packaged under vacuum; 100% aerobic package (control, with the presence of atmosphere air); MAP1 (15% N2 + 80% CO2 + 5% O2), and MAP2 (20% N2 + 70% CO2 + 10% O2 ), and stored at 5°C for 28 days. Samples were taken every 72 hours for the microbiological analyses (total mesophilic count, total psychrotrophic count, coagulase positive Staphylococcus, Salmonella sp., and thermotolerant Coliforms at 45°C) and physicochemical analyses (pH, the nitrogen from the total volatile bases, and trimethylamine), all carried out in triplicate. The results showed that the seasoned cobia sticks remained safe and with good microbiological, physical and chemical quality for a longer period when packed in a modified atmosphere. MAP1 (15% N2 + 80% CO2 + 5% O2) was the system showing the best performance in the maintenance of quality and freshness, demonstrating the feasibility of ensuring quality and a longer shelf life (28 days) at 5°C.

Chemical stability of rainbow trout in icing medium containing pistachio (Pistachia vera) green hull extract during chilled storage

In this study, the effect of icing medium containing different concentration of pistachio (Pistacia vera L. cv. Akbari) green hull extract (PHE) was investigated on the chemical stability of rainbow trout. The fishes were stored for 12 days in flaked ice containing 0, 0.1, 0.2 and 0.3% PHE and the parameters of pH, total volatile base nitrogen (TVB-N), histamine, free fatty acids, peroxide and thiobarbituric acid index (TBA-i) were periodically evaluated. In all experiments, a significant difference was evident between control and fish muscles stored in ice containing PHE. Fish icing with 0.3% PHE could considerably retard the oxidative and hydrolytic rancidity. In addition, it had significant effect on prevention of pH increase and production of volatile basic nitrogen during 12 days storage. PHE could diminish histamine accumulation in fish muscle and improve safety of rainbow trout. Consequently, PHE could have potential of application in icing medium for preservation of fish quality especially fatty ones.

Changes of Dominant Spoilage Bacteria and Biogenic Amines of Taihu White Prawn (Exopalaemon modestus) during Ice Storage

The microbiological and chemical changes in Taihu white prawn (Exopalaemon modestus) during ice storage were evaluated. For the microbiological changes, total viable counts were obtained. PCR coupled with denatured gradient gel electrophoresis was then performed to investigate the changes in microflora. For the chemical changes, total volatile basic nitrogen was determined and biogenic amines were detected. The initial total viable count was 6.2 log CFU/g, which increased to 7.1 log CFU/g after storage at 0°C for 10 days. Pseudomonas sp., Shewanella, Flavobacterium, and Staphylococcus were the dominant bacteria in fresh white prawn, whereas lactic acid bacteria, Pseudomonas sp., Shewanella, and Flavobacterium were dominant in the spoiled products. The initial total volatile basic nitrogen was 7.2 mg/100 g, a value that significantly increased to 30.5 mg/100 g at the end of storage. Putrescine was the dominant biogenic amine, and its content reached 95.5 mg/kg at the end of storage. PCR coupled with denatured gradient gel electrophoresis showed that Chryseobacterium sp., Acidovorax sp., Pelomonas sp., Kinneretia asaccharophila, and uncultured Curvibacter sp. were the dominant strains during storage, whereas Lactococcus garvieae became dominant at the end of storage. This study facilitated the development of preservation techniques that target these predominant spoilage bacteria.

Effects of different ozonized slurry-ice treatments and superchilling storage (-1°C) on microbial spoilage of two important pelagic fish species

Combining different preservative treatments for improving quality and safety of fishery products increasingly receives global research attention. Consistent with this pursuit, the current research was undertaken to determine the effects of different ozonized slurry-ice treatments and superchilling (-1°C) storage on microbial spoilage of European anchovy (Eugraulis encrasicolus) and sardine (Sardina pilchardus), which are two commercially important pelagic fish species. After the catch (within <5 hr) and at defined scheduled storage times, ozone has been discharged once on sardine (herein referred to as "One-T") and repeatedly/sequentially on European anchovy (herein referred to as "Seq-T"). Microbiological analyses enumerated total viable count (TVC), Bacillus spp., Enterobacteriaceae, Lactobacillus spp., Moraxella spp., Shewanella spp., Listeria monocytogenes and Pseudomonas spp. Independent of potential antimicrobial effects of ozone during superchilling storage, no Listeria spp., Shewanella spp., Moraxella spp., and Bacillus spp. were found in all processed samples. While Enterobacteriaceae and Lactobacillus spp. were detected at below 1 log cfu/g, both TVC and Pseudomonas spp. proliferated at different rates throughout superchilling storage. The repeated ozone-treated ("Seq-T") showed lower TVC and Pseudomonas spp. values compared with one-time treated ("One-T") slurry-iced and control samples. Thus, combined slurry-ice and superchilling storage at Seq-T produced improved antimicrobial activity over One-T application. Largely, ozonized slurry-ice outcomes/results appear promising thanks to superchilling storage.

Effect of spice-incorporated starch edible film wrapping on shelf life of white shrimps stored at different temperatures

BACKGROUND

White shrimps (Litopenaeus vannamei) are a major aquaculture product in the world fishery market. The main aim of this study was to investigate the effect of clove- and cinnamon-assimilated starch edible films on the shelf life of white shrimps in terms of maintaining their freshness and other organoleptic properties. Physical, chemical, microbial and sensory qualities of edible film-wrapped white shrimps were studied until they reached their limit of acceptability during storage at different temperatures (10 and 4 °C).

RESULTS

Shrimp samples wrapped with spice-assimilated edible films showed lower bacterial counts. Shelf life extension of edible film-wrapped white shrimps was estimated to be 14 and 12 days for storage at 10 and 4 °C respectively. Reduced lipid oxidation and release of nitrogen base compounds were noted for edible film-wrapped shrimp samples. Good consumer acceptance was noted for edible film-wrapped shrimp samples through sensory evaluation.

CONCLUSION

The results of this study show that spice-fused edible films were effective in inhibiting the growth of microbial populations. Reductions in lipid oxidation and total volatile base nitrogen were also achieved through edible film wrapping of shrimps, which increased their consumer acceptance during sensory evaluation. © 2016 Society of Chemical Industry.

Modified Atmosphere Systems and Shelf Life Extension of Fish and Fishery Products

This review aims at summarizing the findings of studies published over the past 15 years on the application of modified atmosphere (MA) systems for shelf life extension of fish and fishery products. This review highlights the importance of CO₂ in the preservation of seafood products, and underscores the benefits of combining MA technology with product storage in the superchilled temperature range. It is generally accepted that MA technology cannot improve product quality and should not be utilized as a substitute for good sanitation and strict temperature control. Benefits derived from application of MA, however, can significantly impact preservation of product quality and it subsequent shelf-life. For this reason, this review is the first of its kind to propose detailed handling and quality guidelines for fresh fish to realize the maximum benefit of MA technology.

The effects of Aloe vera (Aloe barbadensis) coating on the quality of shrimp during cold storage

Green tiger shrimp (Penaeus semisulcatus) is an important aquaculture species worldwide. Its perishable nature, however, needs preservation methods to ensure its quality and shelf life. In this study, the effects of Aloe vera coating on the quality and shelf life of shrimps during cold storage were investigated. Shrimp samples were dipped in aqueous solutions containing 25%, 50%, 75%, and 100% Aloe vera gel before storage at 4 °C for 7 days. Drip loss, pH, TBA, TVB-N, and texture of both the control and treated shrimp samples were analyzed periodically. There were significant differences between coated shrimps and the control group in all parameters evaluated. Aloe vera at 75% and 100% concentrations was able to prevent lipid oxidation and drip loss properly; however, coatings containing 25% Aloe vera did not have the desired effects on these characteristics. Shrimps coated with higher concentrations of Aloe vera had better textural properties during cold storage. Results also indicated the positive effects of Aloe vera coating on the sensory quality of shrimp.

Impact of the O2 concentrations on bacterial communities and quality of modified atmosphere packaged Pacific white shrimp (Litopenaeus vannamei)

The importance of spoilage-related bacteria in fresh Pacific white shrimp (Litopenaeus vannamei) under different modified atmospheres (MAs) at 4 °C and the effect of O2 were demonstrated in the current study. The changes of bacterial communities in MA-packed shrimp during cold storage were studied by a combined method of plate counts with isolation and identification. Three gas mixtures were applied: 80% CO2 /5% O2 /15% N2, 80% CO2 /10% O2 /10% N2 and 80% CO2 /20% O2, and unsealed packages of shrimp were used as the control. In addition, the TVB-N, pH, whiteness index, and sensory scores were also determined to evaluate the quality changes of shrimp. MA packaging effectively inhibited the increase of total psychrotrophic bacteria counts and H2 S-producing bacteria counts by about 1.7 and 2.1 log cycles, respectively. The growth of Gram-negative spoilage bacteria in shrimp, including Shewanella spp., Aeromonas spp., and Pseudomonas spp., was inhibited by MA packaging, but the growth rate of Gram-positive bacteria such as lactic acid bacteria (LAB) and Brochothrix spp. were less affected by MA as effectively as Gram-negative bacteria. In comparison with the MA-packaged samples, the counts of H2 S producers in shrimp under a CO2 -enriched atmosphere with 20% O2 were slightly lower than the count in samples under an atmosphere with 5% O2 . However, MA with 20% O2 led to higher concentrations of TVB-N, and lower whiteness values and sensory scores. The shelf life of shrimp under 80% CO2 /10% O2 /10% N2 has been prolonged by > 6 d in comparison with the control according to the sensory scores.

Preparation of an novel botanic biopreservative and its efficacy in keeping quality of peeled Penaeus vannamei

A novel botanic biopreservative was successfully prepared by the combination of the bamboo leaves extracts and ebony extracts, designated as ebony-bamboo leaves complex extracts (EBLCE), whose antimicrobial activity was assessed according to an inhibition zone method against 10 common pathogenic and spoilage microorganisms. It was found that EBLCE was more effective from all the chosen microorganisms, as compared by potassium sorbate. Due to its excellent antimicrobial activity, and some additional properties like edibility, safety and economy, EBLCE was selected for further study to evaluate the efficacy in prolonging shelf life and improving the quality of peeled Penaeus vannamei during storage at 4 °C, based on periodical microbiological, chemical and sensory analysis. As a result, EBLCE was observed to prevent spoilage of peeled P. vannamei efficiently as reflected by a distinct decrease in total viable count, pH and total volatile basic nitrogen, as well as a slower decline in the sensory evaluation scores. Therefore, a prolonged shelf life of 16 days was obtained for EBLCE pre-treated peeled shrimps with comparison of 6 days for the control group, demonstrating EBLCE as a promising alternative for preserving food.

Effect of Modified Atmosphere with Varying O2 Concentrations on the Quality of Packed Pacific White Shrimp (Penaeus vannamei) during Cold Storage

The purpose of this study was to evaluate the effect of modified atmosphere packaging (MAP) with varying O2concentrations on the quality changes of Pacific white shrimp during cold storage at (4±1)°C by using the quality indices such as Total viable counts (TVC), TVB-N, pH, firmness, whiteness and sensory evaluation. Results showed that MAP inhibited the microbial growth and the spoilage which was confirmed by the lowered TVC and TVB-N. Among the four MAP groups, shrimp packaged in bags 40%CO2\55%O2\5%N2showed the lowest level of TVC and TVB-N, and shrimp in 40%CO2\5%O2\55%N2had the best appearance with lighter blackspots during storage. Low O2concentration packaging exhibited the ability to retard melanosis, but weakening the ability to impede the spoilage. Extremely high O2concentration with low CO2concentration packaging inhibit the microbial growth compared to the CK, but improved the melonasis of shrimp and reduced its sensory quality rapidly.