Quality assessment of rainbow trout (Oncorhynchus mykiss) fillets during super chilling and chilled storage

Deep learning models with optimized fluorescence spectroscopy to advance freshness of rainbow trout predicting under nonisothermal storage conditions

This study established long short-term memory (LSTM), convolution neural network long short-term memory (CNN_LSTM), and radial basis function neural network (RBFNN) based on optimized excitation-emission matrix (EEM) from fish eye fluid to predict freshness changes of rainbow trout under nonisothermal storage conditions. The method of residual analysis, core consistency diagnostics, and split-half analysis of parallel factor analysis was used to optimize EEM data, and two characteristic components were extracted. LSTM, CNN_LSTM, and RBFNN models based on characteristic components of EEM used to predict the freshness indices. The results demonstrated the relative errors of RBFNN models with an R2 above 0.96 and relative errors less than 10% for K-value, total viable counts, and volatile base nitrogen, which were better than those of LSTM and CNN_LSTM models. This study presents a novel approach for predicting the freshness of rainbow trout under nonisothermal storage conditions.

Effect of tragacanth gum-chitin nanofiber film containing free or nano-encapsulated cumin essential oil on the quality of chilled turkey burgers packed with oxygen absorber

This research was undertaken to assess the effect of tragacanth gum-chitin nanofiber (TG-CNF) film containing free (CEO) or encapsulated cumin essential oil (CNE) combined with oxygen absorber (OA) packaging on the shelf-life of ready-to-cook (RTC) turkey breast burgers during chilled storage. The experimental groups were OA and TG-CNF as single treatments, TG-CNF + CEO, TG-CNF + CNE, and TG-CNF + OA as binary treatments, TG-CNF + CEO + OA and TG-CNF + CNE + OA as ternary treatments, and control. The samples were stored at 3°C for 20 days and analyzed for microbial, physicochemical, and sensory attributes. Binary treatments, when compared to single treatments, and ternary treatments, when compared to binary treatments, exhibited enhanced effectiveness in managing microbial growth, hindering physicochemical alterations, and decelerating sensory alterations. At day 20, TG-CNF + CNE + OA group was identified as the most effective group in inhibiting the growth of total mesophilic bacteria (TMB), total psychrophilic bacteria (TSB), and coliforms (final counts were 4.8, 4.16, and ≤1 log CFU/g, respectively), and TG-CNF + CNE + OA and TG-CNF + CEO + OA groups were known as the most effective groups in inhibiting lactic acid bacteria (LAB) (final counts were 4.71 and 5.15 log CFU/g, respectively). Furthermore, the TG-CNF + CNE + OA treatment proved to be the most effective group in reducing the total volatile nitrogen (TVN) (final level was 19.2 mg N/100 g) and thiobarbituric acid reactive substances (TBARS) (final level was 0.119 mg malondialdehyde (MDA)/kg). TG-CNF + CNE + OA and TG-CNF + CEO + OA were the most efficient groups to delay the increasing rate of cooking loss (final values were 23.3% and 24.6%) and pH (final values were 7.01 and 6.99). The sample's shelf-life was 4 days in control and TG-CNF, 8 days in OA and TG-CNF + OA, 12 days in TG-CNF + CEO, 16 days in TG-CNF + CNE and TG-CNF + CEO + OA, and at least 20 days in TG-CNF + CNE + OA. As a result, the incorporation of TG-CNF + CNE alongside OA packaging emerges as a highly effective active packaging method for preserving RTC turkey breast burgers during chilled storage.

Regulating effects of low salt dry-curing pre-treatment on microbiota, biochemical changes and flavour precursors of grass carp (Ctenopharyngodon idella) fillets during storage at 4 °C

Low salt dry-curing (LSD), as a healthier pre-treatment for the preservation of fishery products, is a potential technique substitute for excessively salty curing. The regulatory effects of 2 % and 3 % LSD on the quality evolution through an intrinsic correlation between microbiota succession and flavour precursors of refrigerated grass carp fillets were investigated in this study. The results showed that the LSD pre-treatment was effective in promoting proteolysis, free amino acid and fatty acid metabolism with the microbiota succession and quality evolution. Compared with unpre-treated samples, the 3 % LSD pre-treatment effectively extended the shelf life by 10 days within the acceptable quality attributes. Not only did the LSD pre-treatment lead to catalytic microbiota succession and inhibitive spoilage substance production but it also improved the flavour precursors, which are taste-active amino acids and polyunsaturated fatty acids (PUFAs). Moreover, considerable correlations between quality attributes, taste-active amino acids, PUFAs and microbiota were obtained.

Degradation mechanism and development of detection technologies of ATP-related compounds in aquatic products: recent advances and remaining challenges

The degradation of ATP-related compounds is an important biochemical process that reflects the freshness of aquatic products after death. There has been considerable interest in investigating the factors affecting the degradation of ATP-related compounds in aquatic products and in developing techniques to detect them. This review provides the latest knowledge on the degradation mechanisms of ATP-related compounds during the storage of aquatic products and discusses the latest advances in ATP-related compound detection techniques. The degradation mechanisms discussed include mainly degradation pathways, endogenous enzymes, and microbial mechanisms of action. Microbial activity is the main reason for the degradation of IMP and related products during the mid to late storage of aquatic products, mainly through the related enzymes produced by microorganisms. Further elucidation of the degradation mechanisms of ATP-related compounds provides new ideas for quality control techniques in raw aquatic products during storage. The development of new technologies for the detection of ATP-related compounds has become a significant area of research. And, biosensors further improve the efficiency and accuracy of detection and have potential application prospects. The development of biosensor back-end modalities (test strips, fluorescent probes, and artificial intelligence) has accelerated the practical application of biosensors for the detection of ATP-related compounds.

Dynamic changes in postmortem quality of mirror carp (Cyprinus carpio L.): Based on oxidation reaction and mitochondrial function properties

The dynamic changes in the postmortem quality of mirror carp (Cyprinus carpio L.) were investigated. With extended postmortem time, conductivity, redness, lipid oxidation, and protein oxidation all increased, while lightness, whiteness, and freshness decreased. At 4 h postmortem, the pH value reached a minimum (6.58), while the centrifugal loss and hardness reached a maximum (17.13% and 2539 g). Additionally, variations in mitochondria-related parameters during apoptosis were studied. Within 72 h postmortem, the content of reactive oxygen species initially decreased and subsequently increased; furthermore, there was a significant increase in the mitochondrial membrane permeability transition pore, membrane fluidity, and swelling (P < 0.05). Meanwhile, the cytosolic cytochrome c level decreased from 0.71 to 0.23, which indicated potential mitochondrial damage. Thus, mitochondrial dysfunction during postmortem aging can give rise to oxidation and the production of ammonia and amine compounds, which leads to flesh quality deterioration.

Synthesis of spirulina loaded chitosan nanoparticles from prawn, Macrobrachium nipponense shell for extending the shelf life of pike-perch (Sander lucioperca) fillet during refrigerated storage

BACKGROUND

This study was aimed to synthesize polymeric chitosan nanoparticles (CSNPs) from Macrobrachium nipponense shells using sodium triphosphate (TPP) as a crosslinker that was incorporated with spirulina extract (SPE) to improve the shelf life of pike-perch during refrigerated storage (4 °C).

RESULTS

The encapsulation efficiency (EE) of SPE-loaded CSNPs decreased from 67% to 32%, and loading capacity (LC) was increased (10-14%) depending on their loaded SPE concentrations. The initial burst effect, followed by a slow-release at pH 7 (24 h), was observed. Free SPE and SPE incorporated CSNPs decreased microbial counts (total viable count, total psychotropic count, pseudomonas, and lactic acid bacteria) compared to control and unloaded CSNPs. Samples treated with free SPE or SPE-loaded CSNPs showed higher changes in odor, color, TVB-N (total volatile basic nitrogen), and TBA (thiobarbituric acid) compared with the unloaded CSNPs batch (P ≤ 0.05) until the tenth day of storage. However, fish fillets coated with SPE-loaded CSNPs had the highest overall consumer acceptability and the lowest values for TVB-N and TBA at the end of storage (14^th  day). Controlled release of bioactive compounds in batches treated with SPE-CSNPs could delay the microbial degradation and enhance chemical reactions (TBA and TVB-N) in comparison to pure SPE during storage time.

CONCLUSION

The incorporation of SPE in polymeric CSNPs can be considered as a promising material for controlled delivery of natural bioactive agents, and preservation of Pike perch quality during refrigerator storage. © 2022 Society of Chemical Industry.

Antimicrobial Potential of Plastic Films Incorporated with Sage Extract on Chicken Meat

The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in prolonging the storage of chicken breast meat without affecting their quality.

Prediction in the Dynamics and Spoilage of Shewanella putrefaciens in Bigeye Tuna (Thunnus obesus) by Gas Sensors Stored at Different Refrigeration Temperatures

Shewanella putrefaciens have a faster growth rate and strong spoilage potential at low temperatures for aquatic products. This study developed a nondestructive method for predicting the kinetic growth and spoilage of S. putrefaciens in bigeye tuna during cold storage at 4, 7 and 10 °C by electronic nose. According to the responses of electronic nose sensor P30/2, the fitted primary kinetic models (Gompertz and logistic models) and secondary model (square root function model) were able to better simulate the dynamic growth of S. putrefaciens, with high R² and low RMSE values in the range of 0.96–0.99 and 0.021–0.061, respectively. A partial least squares (PLS) regression model based on both electronic nose sensor response values and electrical conductivity (EC) values predicted spoilage of S. putrefaciens in bigeye tuna more accurately than the PLS model based on sensor signal values only. In addition, SPME/GC-MS analysis suggested that 1-octen-3-ol, 2-nonanone, 2-heptanone, dimethyl disulfide and methylamine, N, N-dimethyl- are the key VOCs of tuna inoculated with S. putrefaciens.

Effects of Whey Protein Isolate-Based Film Incorporated with Tarragon Essential Oil on the Quality and Shelf-Life of Refrigerated Brook Trout

The efficiency of some films prepared from heat-denatured whey protein isolate solutions on the quality and shelf-life of brook trout samples during storage at 4 °C was studied in this research (WPIf-a film based on whey protein isolate and WPIf+2.5%TEO-a film based on whey protein isolate incorporated with 2.5% tarragon essential oil). The control and covered fish samples were periodically assessed (at 3 days) over 15 days of storage for the physicochemical (pH; EC, electrical conductivity; TVB-N, total volatile basic nitrogen; TBARS, thiobarbituric acid reactive substances; color), microbiological (TVC, total viable count; PTC, psychrotrophic count; LAB, lactic acid bacteria; H₂S-producing bacteria), and sensory properties (color discoloration; odor; overall acceptability). The WPIf+2.5%TEO has proven enhanced quality preservation effects compared to WPIf by showing lower values for physicochemical parameters, lower microbial loads, and higher sensory scores in the fish sample. All these effects have led to an extension of the sample’s shelf-life. In conclusion, the tarragon essential oil has conferred antioxidant and antimicrobial properties to the film. Thus, the WPIf+2.5%TEO could be a promising material for the packaging of fresh brook trout during refrigerated storage.

The effects of incorporated resveratrol in edible coating based on sodium alginate on the refrigerated trout (Oncorhynchus mykiss) fillets' sensorial and physicochemical features

The goal of this study was examining the effects of sodium alginate coating (SA) containing resveratrol (R) on enhancement rainbow trout fillets' shelf-life. Treatments of the study were as follows: control, SA, SA-R 0.001% and SA-R 0.003%. Storage of the samples was done for 15 days at 4 °C. To analyze samples, 3-day intervals were used. Compared to the uncoated trout, the values of pH, peroxide and K were significantly lower in the coated samples (p < 0.05). R enhanced the impacts of alginate on extending the samples' shelf life. Sensory analyses showed that R improved the sensory scores significantly (p < 0.05); besides, it did not show more changes on the sensory features and was invisible in the surface of samples. In the conclusion, R was suggested to be a strong alternative to synthetic antioxidants in refrigerated trout fillet in very low concentrations with many health benefits.

Impact of glazing based on chitosan-gelatin incorporated with Persian lime (Citrus latifolia) peel essential oil on quality of rainbow trout fillets stored at superchilled condition

In this research, a new ice-glazing based on chitosan-gelatin (Ch-Gl) incorporated with Persian lime peel essential oil (LEO), and superchilled storage was established to assess the microbial, physicochemical, and sensory quality of rainbow trout fillets. The fillets were immersed in distilled water (control), Ch-Gl, Ch-Gl + 1% LEO, and Ch-Gl + 2% LEO to form glazing layer on the surface, then stored at -1.4 °C for 30 days. All treatments delayed the growth of total mesophilic bacteria, total psychrotrophic bacteria, Enterobacteriaceae, and lactic acid bacteria compared to control during the storage period. The treatments also retarded the increase in the contents of total volatile nitrogen, conjugated dienes, thiobarbituric acid reactive substances, protein carbonyls, pH, and electric conductivity during storage. The freshness indexes i.e. K and F_r values were improved in treated groups compared to control group. The combined treatments (Ch-Gl + 1% or 2% LEO) were more effective than Ch-Gl alone to inhibit the microbial growth, retard the physicochemical deterioration, and improve freshness indexes in the fillets. It can be concluded that ice-glazing based on Ch-Gl incorporated with LEO, and superchilled storage is effective to enhance the quality and shelf-life of rainbow trout fillets.

Changes in the Quality of Chicken Breast Meat due to Superchilling and Temperature Fluctuations during Storage

The aim of this study was to determine the changes in chicken breast meat quality (water-holding capacity, color, texture, myofibrillar fragmentation index (MFI), total protein solubility, thiobarbituric acid reactive substances (TBARS), total viable count (TVC), and lactic acid bacteria (LAB) count) due to storage under superchilling conditions (−1.3°C) and fluctuating temperatures (ranging from −20°C to −5°C) as compared to the quality of meat stored at chilled (2–4°C) and frozen (−20°C) temperatures, respectively. Results indicated that the TVC and LAB count of the chilled and superchilled breast meat increased with storage time. TVC of the chilled and superchilled breast meat reached the safety level of 7 log cfu/g at approximately day 8 and18, respectively. This suggested that the superchilling method extended the storage duration by 10 days. Weight loss and TBARS of the chilled and superchilled samples tended to increase with increasing storage time. The color, texture, protein solubility, and MFI were stable throughout the entire storage period of the chilled (9 days) and superchilled (28 days) samples. Results indicated that while three cycles of storage temperature fluctuation influenced the weight loss and dry matter of the meat, they did not affect the TVC, LAB count, texture, color, pH, MFI, and protein solubility. The superchilling technique (−1.3°C) could extend the shelf-life of meat and maintain the quality of chicken breast meat. Fluctuations in temperature during frozen storage decreased the water-holding capacity of chicken breast meat, indicating that temperature stability should be maintained during frozen storage.

Effect of superchilled storage on shelf life and quality characteristics of M. longissimus lumborum from Chinese Yellow cattle

The effect of superchilled storage (SC, -4 °C) on shelf life and quality characteristics of M. longissimus lumborum from Chinese Yellow cattle compared with traditional chilling (TC, 2 °C) and frozen storage (-18 °C) was studied. The shelf life of beef steaks held at -4 °C extended to 12 weeks based on the total volatile basic nitrogen (TVB-N) value, which was 2.4 times longer than steaks stored at 2 °C. As the storage time increased, SC samples showed a lower increase of the total aerobic count (TAC), pH and thiobarbituric acid reactive substances (TBARS) values compared to TC samples. Further, L^⁎ and a^⁎ values of SC samples changed more slowly than that of TC samples. Beef steaks held frozen had a longer shelf life than SC steaks, however, the shear force of frozen steaks remained above 55 N throughout the storage time indicative of toughness. Consequently, SC offers an effective approach for maintaining better shelf life and quality of beef steaks.

Impact of Diets Containing Plant Raw Materials as Fish Meal and Fish Oil Replacement on Rainbow Trout (Oncorhynchus mykiss), Gilthead Sea Bream (Sparus aurata), and Common Carp (Cyprinus carpio) Freshness

The present study aimed to evaluate whether the total or high substitution of fish meal (FM) and fish oil (FO) by sustainable plant raw materials (plant meal and oils) in long-term feeding for rainbow trout, gilthead sea bream, and common carp can result in spoilage alterations during ice storage. These three species were fed throughout their whole rearing cycle with plant-based diets and compared to counterparts that received FM/FO-based diets or commercial-like diets. Sensory QIM schemes adopted for these species and ATP breakdown products (K-value and components) were used to evaluate the freshness. Sensory acceptability of 14, 15, and 12 days was found for rainbow trout, gilthead sea bream, and common carp, respectively. This corresponded to K-values of approximately 80%, 35%, and 65% for rainbow trout, gilthead sea bream, and common carp, respectively. No major effect of dietary history on postmortem shelf life was shown for gilthead sea bream and common carp; neither sensory-perceived nor chemical freshness showed diet-related differences. Rainbow trout fed with the plant-based diet exhibited slightly worse sensory freshness than fish fed with FM/FO-based diets, at the end of shelf life. These findings imply that FM and FO can be successfully substituted without major impacts on shelf life of fish.

Biogenic Amines and Predictive Models of Quality of Rainbow Trout ( Oncorhynchus mykiss ) Fillets during Storage

To estimate biogenic amines and changes in quality of rainbow trout ( Oncorhynchus mykiss ) fillets at different temperatures, we determined the sensory attributes, total volatile basic nitrogen (TVB-N), total viable counts (TVC), and biogenic amines (BAs) of samples that were untreated (CK) or dry cured with 1.8% salt (T). There was no significant difference between CK and T samples in terms of TVB-N, TVC, and BAs. TVB-N and TVC increased significantly (P < 0.05) with storage time at 3, 9, and 15°C. Putrescine (PUT) and cadaverine (CAD) increased significantly (P < 0.05) at -3, 3, 9, and 15°C during storage. Histamine formed more easily when storage temperatures were higher. The kinetic models of sensory scores for TVB-N, TVC, PUT, CAD, and the sum of PUT and CAD (PUT+CAD) in T samples versus storage time and temperature were developed based on the Arrhenius equation. High regression coefficients (R² > 0.9) indicated the acceptability of the kinetic model for predicting changes in the quality of the rainbow trout fillets. Relative errors between predicted and experimental values of TVB-N, TVC, and PUT+CAD were all within 10% except for TVB-N on day 6. The prediction model based on TVB-N, TVC, and PUT+CAD can be applied to evaluate changes in quality of rainbow trout fillets from -3 to 15°C (270 to 288 K).