MICROBIOLOGICAL AND NUTRITIONAL QUALITY OF SOUS VIDE OR TRADITIONALLY PROCESSED FISH: INFLUENCE OF FAT CONTENT

Effects of Sous-Vide on Quality, Structure and Flavor Characteristics of Tilapia Fillets

To investigate the effects of traditional high-temperature cooking and sous-vide cooking on the quality of tilapia fillets, muscle microstructure, texture, lipid oxidation, protein structure, and volatile compounds were analyzed. In comparison with samples subjected to traditional high-temperature cooking, sous-vide-treated samples exhibited less protein denaturation, a secondary structure dominated by α-helices, a stable and compact structure, a significantly higher moisture content, and fewer gaps in muscle fibers. The hardness of the sous-vide-treated samples was higher than that of control samples, and the extent of lipid oxidation was significantly reduced. The sous-vide cooking technique resulted in notable changes in the composition and relative content of volatile compounds, notably leading to an increase in the presence of 1-octen-3-ol, α-pinene, and dimethyl sulfide, and a decrease in the levels of hexanal, D-limonene, and methanethiol. Sous-vide treatment significantly enhanced the structural stability, hardness, and springiness of muscle fibers in tilapia fillets and reduced nutrient loss, enriched flavor, and mitigated effects on taste and fishy odor.

Analysis of Quality and Color Properties according to the Gas Composition (Modified Atmosphere Packaging) of Pork Sous-Vide Ham Preserved in Natural Brine

The purpose of this study was to analyze whether seawater has positive effects on appearance characteristics, such as CIE a*, and to determine the gas composition concentration that is suitable for maintaining it. Pork hind meat was cured with four types of curing agent for 5 d at 4°C. The different curing agents comprised the control salt, control nitrite pickling salt (CN), treatment brine, and treatment bittern (BT). The cured hams were cooked at 65°C for 4 h and packaged at O₂:N₂ gas ratios of 7:3, 8:2, and 9:1 for 3 wk. The physicochemical properties were assessed immediately after heating the sample, and the color properties were measured after a 3 wk storage period. Based on the correlation results of the physicochemical properties, BT had a higher curing and cooking yield than the other treatments, owing to its high salinity. Results of color properties for BT (7:3) and CN (8:2) showed similar color CIE L*, CIE a* chroma, and hue angle values. Therefore, BT can be said to be a sous-vide curing agent suitable for preserving the color of ham, and a high nitrogen concentration of 30% helps to maintain the appearance of seawater sous-vide ham.

Quality changes of sous-vide cooked and blue light sterilized Argentine squid (Illex argentinus)

The present work was carried out to investigate the quality changes and shelf life of blue light (Blu-ray) irradiated sous-vide cooked (SVC) Argentine squid (Illex argentinus) during storage at 0, 5, and 10 °C. Sensory evaluation, color, shear force, lipid oxidation levels, total viable counts (TVC), and psychrophilic bacterial count were used to study the changes in storage quality of SVC squid at different temperatures. Results showed that the high-quality endpoints of Blu-ray irradiated Argentine squid were 360, 144, and 72 h, and the shelf-life endpoints were 504, 240, and 120 h during storage at 0, 5, and 10 ℃, respectively. The redness values of irradiated squid did not differ significantly (p >0.05) during the storage, the brightness and yellowness values of irradiated squid showed an increasing trend, and the sheer force initially increased and then decreased. The thiobarbituric acid reactive substance of each squid stored at low temperature increased with the extension of the storage period, indicating that they exhibited fat oxidation with the extension of the storage period. The TVC and the number of Psychrobacter species increased with the storage period. The correlation analysis suggested that TVC and Psychrobacter count as indicators of quality changes in Argentine squid during low-temperature storage were in good agreement with sensory scores (R2 >0.9). Additionally, our results showed that Blu-ray sterilization played a positive role by inducing photosensitive oxidation and decreasing TVC and the total number of Psychrobacter than the control group during storage of SVC squid after Blu-ray irradiation. This study provides a theoretical basis for applying Blu-ray sterilization in aquatic product processing.

The antimicrobial effect of thyme and rosemary essential oils against Listeria monocytogenes in sous vide turkey meat during storage

The research was aimed to study the impact of sous vide thermal treatment on the microbiological quality of fresh turkey breast meat after treatment with thyme and rosemary EOs and the survival of Listeria monocytogenes on the turkey meat samples. The samples were vacuum-packed and cooked at 55 °C, 60 °C, and 65 °C for 5, 15, 30 and, 60 min. There was an amount of 5 g (5 ±0.2 g) of the sample placed in PA/PE film bags and inoculated with 100 μL of L. monocytogenes inoculum. The sample was incubated at 37 °C for 18 h after bag sealing. The samples were tested on the 1st and 3rd days of experiments. The microbiological quality of fresh turkey breast meat was assessed by the detection of total microbial counts and meat microbiota was identified by mass spectrometry using MALDI-TOF MS Biotyper (Bruker Daltonics, Germany). Microbial counts differed significantly depending on temperature and time and the microbial counts ranged from 2.21 log cfu.g-1 to 8.26 log cfu.g-1 on the 1st and 3rd day of the experiment. The study shows that the sous vide method with essential oils combination is an effective method and it can be used to protect the microbiota of turkey meat and L. monocytogens survival, however, the quality of raw material is crucial.

Salmon (Salmo salar) Cooking: Achieving Optimal Quality on Select Nutritional and Microbiological Safety Characteristics for Ready-to-Eat and Stored Products

This study was performed in order to assess technological characteristics, proximate composition, fatty acids profile, and microbiological safety of sous-vide processed salmon in comparison with steaming and roasting. The cooking loss was lower in the sous-vide method (6.3-9.1%) than in conventional methods (11.6-16.2%). The preparation of salmon using sous-vide was more time- and energy-consuming than steaming. The dry matter content of the salmon fillets was higher in conventionally processed samples than sous-vide due to the evaporation of water, and it was connected with total protein (r = 0.85) and lipid content (r = 0.73). Analysis of the fatty acids profile only revealed significant differences in six fatty acids. All of the heat treatment methods ensured microbiological safety with regard to coagulase-positive Staphylococcus, E. coli, Listeria monocytogenes, and Salmonella spp. However, in sous-vide (57 °C, 20 min) and steamed samples after storage Enterobacteriaceae bacteria (<104) was detected. Summing up, high parameters of sous-vide salmon cooking, when considering both technological parameters, nutritional value, and microbiological status should be recommended.

Sous-Vide as a Technique for Preparing Healthy and High-Quality Vegetable and Seafood Products

Sous-vide is a technique of cooking foods in vacuum bags under strictly controlled temperature, offering improved taste, texture and nutritional values along with extended shelf life as compared to the traditional cooking methods. In addition to other constituents, vegetables and seafood represent important sources of phytochemicals. Thus, by applying sous-vide technology, preservation of such foods can be prolonged with almost full retention of native quality. In this way, sous-vide processing meets customers' growing demand for the production of safer and healthier foods. Considering the industrial points of view, sous-vide technology has proven to be an adequate substitute for traditional cooking methods. Therefore, its application in various aspects of food production has been increasingly researched. Although sous-vide cooking of meats and vegetables is well explored, the challenges remain with seafoods due to the large differences in structure and quality of marine organisms. Cephalopods (e.g., squid, octopus, etc.) are of particular interest, as the changes of their muscular physical structure during processing have to be carefully considered. Based on all the above, this study summarizes the literature review on the recent sous-vide application on vegetable and seafood products in view of production of high-quality and safe foodstuffs.

TRENDS OF PROCESSED PRODUCTS OF SQUID

Currently, technologies that allow to preserve the native properties of raw materials in the finished product as much as possible thanks to the soft modes of technological processes deserve special attention. An important condition for obtaining healthy food products is the availability of a raw material base and technical means of extracting aquatic biological resources. The article shows that in China, a healthy lifestyle and the consumption of healthy food products are gaining popularity. China is a country that demonstrates absolute dominance in the production of shellfish, both aquaculture and in squid fishing. Despite this, there is a shortage of healthy food products in the domestic food market in China due to the uneven distribution of aquatic bioresources. The main type of processed shellfish are squids, which are traditionally very popular in China. In addition to frozen processed squid and other primary processed products, the main products from squid are minced squid, sliced squid and chopped squid, as well as various types of canned food. The article shows the high nutritional and biological value of squid, which is provided by high-grade proteins and essential polyunsaturated fatty acids. But when processing squids, a number of problems arise associated with the deterioration of organoleptic properties and a decrease in the biological value of the finished product. This article is a review and reveals a number of issues related to the features of the fractional composition of muscle tissue proteins of various raw materials. Also analyzed the changes in the physico-chemical parameters of proteins in a wide range of temperature effects. The article presents a promising type of technological processing, which allows to eliminate certain disadvantages of traditional technologies such as hard, dry consistency, weight loss of the finished product, as well as the loss of valuable extractive substances that provide organoleptic properties of food products. Such technologies with minimal impact on the technological properties of the finished product include SousVide technology. SousVide is a technology of low-temperature preparation of food products in a vacuum, which allows reliable monitoring of sensory performance and microbiological safety of products with strict observance of technological regulations.

Effect of Various Cooking Methods on Technological and Sensory Quality of Atlantic Salmon (Salmo salar)

The aim of the study was to evaluate the effect of heat treatment salmon quality using the sous-vide method (57 °C, 20 min and 63 °C, 80 min) in comparison with traditional methods (steam cooking, roasting). The yield of process and sensory quality (sensory profile, consumer liking) and the color and texture of salmon was measured. Salmon processed with the sous-vide method was characterized by a statistically significantly (p ≤ 0.05) higher yield and water content than the samples prepared by steaming and roasting. Statistically higher (p ≤ 0.05) consumer preference for salmon prepared using higher parameters of the sous-vide process (63 °C, 80 min) compared with low parameters (57 °C, 20 min) was stated. Parameters of the sous-vide processing (57 °C, 20 min) have a negative effect on salmon quality. It was observed that as the temperature and time of the process increased, the intensity of the flavor and odor attributes of cooked fish also increased, while the intensity of raw fish, juiciness, tenderness, and softness decreased. The color of salmon also changed. Based on the results, we recommend the following parameters of process in preparing salmon using the sous-vide method: 63 °C for 80 min.

Superchilled storage (-2.5 ± 1°C) extends the retention of taste-active and volatile compounds of yellow-feather chicken soup

This work investigated the effects of refrigerated storage (RS: 4 ± 1°C) and superchilled storage (SS: -2.5 ± 1°C) on non-volatile and volatile compounds in chicken soup made from Chinese yellow-feather broilers. The results from total viable count (TVC) and coliform analysis showed that soups were safe for human consumption after a storage period of 42 days. SS resulted in a significantly (p < .05) higher content of free amino acids (umami and sweet taste) and 5'-nucleotides (inosine 5'-monophosphate and adenosine 5'-monophosphate) from 21 to 42 days compared to RS. Hexanal, (E)-2-decenal, (E,E)-2,4-decadienal and 2-pentyl furan were described as the primary odorants. SS showed significantly lower values (p < .05) for ketones and hydrocarbons, higher values for aldehydes and alcohols from 14 to 42 days, when compared to RS. The results suggest that SS improved the flavor retention of chicken soup after 21 days of storage and is a potential alternative treatment compared to RS.

Effects of sous-vide method at different temperatures, times and vacuum degrees on the quality, structural, and microbiological properties of pork ham

This study evaluated the influence of different factors on pork hams cooked by sous-vide method. The quality and structural and microbiological properties of the treated samples were compared with those of controls. Samples were subjected to treatment at different combinations of temperature (61 °C or 71 °C), time (45 or 90 min), and vacuum degree (98.81% or 96.58%). The control sample was air packaged and boiled for 45 min in boiling water. Temperature and vacuum degree affected quality properties, while the effect of time was limited. Samples cooked at 61 °C showed higher moisture content, redness, and pink color of the meat juice, whereas samples cooked at 71 °C showed higher cooking loss rate, lightness, and volatile basic nitrogen values. Texture analysis indicated tenderer meat for the treatment group than the control. No microbial growth was detected in any treatment groups. Meat cooked at 61 °C and 98.81% vacuum showed more spacious arrangement of meat fiber.

Kinetic modeling to study the quality of tambaqui (Colossoma macropomum) sous vide during storage at different temperatures

This study aimed to assess the changes in quality of tambaqui sous vide during refrigerated storage using degradation kinetics. Tambaqui sous vide was prepared and stored at three temperatures (1, 4, 10 °C). The microorganism counts and the physicochemical analyses were analyzed every three days. The results obtained were fitted to the Labuza models and by Arrhenius equation. The results of the microbiological and physicochemical analyses obtained better fits to the zero-order model. The Arrhenius equation better fit to the velocity constants of the zero-order model, which showed that the changes in the values of attributes are related to temperature. Higher Ea values were found for the microorganism counts than for the physicochemical parameters, which proves the greater dependency of microorganisms on variations in temperature. The assessment of changes in quality based on temperature allows the storage conditions to be optimized.

Development of Pangasius steaks by improved sous-vide technology and its process optimization

The present study embarked on the objective of optimizing improved sous-vide processing condition for development of ready-to-cook Pangasius steaks with extended shelf-life using response surface methodology. For the development of improved sous-vide cooked product, Pangasius steaks were treated with additional hurdles in various combinations for optimization. Based on the study, suitable combination of chitosan and spices was selected which enhanced antimicrobial and oxidative stability of the product. The Box-Behnken experimental design with 15 trials per model was adopted for designing the experiment to know the effect of independent variables, namely chitosan concentration (X₁), cooking time (X₂) and cooking temperature (X₃) on dependent variable i.e. TBARS value (Y₁). From RSM generated model, the optimum condition for sous-vide processing of Pangasius steaks were 1.08% chitosan concentration, 70.93 °C of cooking temperature and 16.48 min for cooking time and predicted minimum value of multiple response optimal condition was Y = 0.855 mg MDA/Kg of fish. The high correlation coefficient (R² = 0.975) between the model and the experimental data showed that the model was able to efficiently predict processing condition for development of sous-vide processed Pangasius steaks. This research may help the processing industries and Pangasius fish farmer as it provides an alternative low cost technology for the proper utilization of Pangasius.

Change in physical and chemical characteristics related to the binomial time-temperature used in sous pasteurization see Tambaqui (Colossoma macropomum)

The goal of this study was to evaluate sous vide fish and assess the influence of time and temperature on the pasteurization process through quality parameters. The raw material (tambaqui fillets) and the sous vide underwent physical, physicochemical, and microbiological analyses. A sauce was prepared containing soy sauce, water, horseradish and garlic flakes. The product's pasteurization parameters of time and temperature were defined according to a 22 central composite rotatable design (CCRD), and the dependent variables were water holding capacity (WHC) and instrumental texture aiming at obtaining high WHC values for the product to maintain the desired juiciness. The microbiological analysis required by legislation have indicated that the fish fillets and sous vide were within de standard. The values of total coliforms found in the samples (fillets and sous vide) analyzed were below the critical level of 10² CFU/g. The counts of sulphite-reducing clostridia and psychrotrophic and mesophilic bacteria on plates in the samples were <1x10 CFU/g. In conclusion, temperature was the most important factor in the pasteurization process, significantly contributing to the quality of the final product. The mathematical models proposed were considered predictive for each response.

Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage

Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (p<0.05). The percentage of myoglobin denaturation (PMD) of the CA groups was also increased according to the level of CA during storage. Total aerobic counts, Enterobacteriaceae counts, volatile basic nitrogen and thiobarbituric acid reactive substances (TBARS) were generally lower in the citric acid-treated samples than in untreated ones, indicating extended shelf life of the cooked chicken breast dipped in citric acid solution. The shear force of the 2CIT and 5CIT groups was significantly lower (p<0.05). The findings indicated positive effects in the physicochemical properties and storage ability of sous vide chicken breast at 2% and 5% citric acid concentrations.

Quality and safety of fish curry processed by sous vide cook chilled and hot filled technology process during refrigerated storage

Fish curry, a traditional Indian dish was prepared from farmed fish Cobia ( Rachycentron canadum), packaged by two different cook-chill processes namely, sous vide cook chilled and hot filled technology and held at 2 °C. Biochemical composition revealed that fish curry contained 5% protein and 6% fat. Omega-3 fatty acids, eicosapentaenoic acid (EPA) retained 55.44% while docosahexaenoic acid (DHA) retained 29% during cook-chilling process. The major fatty acids in fish curry were C18:2, C12:0, C16:0 and C18:1. Shelf-life of sous vide cook chilled and hot filled technology processed fish curry were 8 and 12 weeks, respectively. Total bacterial counts were detected after 4 weeks and 12 weeks in sous vide cook chilled and hot filled technology processes, respectively. Total staphylococci were detected in sous vide cook chilled and hot filled technology processed cobia fish curry after 4 and 12 weeks, respectively. Total bacilli, anaerobic sulfite reducing clostridia, Salmonella, and lactic acid bacteria were absent. Hot filled technology process was more efficient and could be applied for chilled fish curry preservation for 12 weeks without any safety problems.