Using maltodextrin and state diagrams to improve thermal transitions in tilapia fillet (Oreochromis spp.).

BACKGROUND: Tilapia (Oreochromis spp.) in the form of frozen fillets is one of the fishes with the highest commercial production levels worldwide. However, protein denaturation, membrane rupture, and lipid oxidation are commonly observed in fillets when stored at standard commercial freezing temperatures for long periods. This study proposes, for the first time, the use of maltodextrin and state diagrams to define processing strategies and suitable storage temperatures for fresh and dehydrated tilapia fillets. Differential scanning calorimetry (DSC) was used to study the effect of maltodextrin weight fractions ( W MD ) of 0, 0.4, and 0.8 on the thermal transitions of tilapia fillets as a function of solid mass fractions ( W s ). RESULTS: The glass transition temperature curve ( T g vs . W s ) and characteristic parameters of maximal freeze concentration ( T g ' , T m ' , W s ' ) of tilapia increased significantly with the addition of maltodextrin. Using developed state diagrams, freezing and storage temperatures of -22 °C, -15 °C, and -10 °C (P < 0.05) for long-term preservation were defined for tilapia fillets produced with W MD of 0, 0.4, and 0.8. CONCLUSION: Maltodextrin is an excellent alternative as a cryoprotectant and drying aid to increase the thermal parameters of tilapia fillets by achieving frozen storage temperatures above the standard commercial freezing temperature of -18 °C. © 2023 Society of Chemical Industry.

Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage / Extrato de chá verde age sobre a qualidade de filés de pescado durante o armazenamento por congelamento

This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg / mL) and CS 625 (C. sinensis extract 625 µg / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage.

O objetivo deste estudo foi investigar os efeitos do extrato de folhas de chá verde (Camellia sinensis) na qualidade de filés de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 ± 2 ° C). O estudo incluiu três tratamentos: imersão dos filés de bagre listrado em água fria da torneira como um tratamento de controle, em solução de extrato de Camellia sinensis 7,63 µg / mL e em solução de extrato de Camellia sinensis 625 µg / mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, três, seis, nove, 12 e 18 meses. Os parâmetros avaliados incluíram contagem viável total, parâmetros físico-químicos (capacidade de retenção de água, nitrogênio básico volátil total, valor de peróxido, substâncias reativas ao ácido tiobarbitúrico, umidade e pH), propriedades sensoriais e medição de cor. Os resultados mostraram que os filés de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidação de lipídios, inibiram o crescimento de bactérias e aumentaram as propriedades sensoriais em comparação com as amostras não tratadas. Além disso, o tratamento do extrato de Camellia sinensis não afetou o pH, a umidade, a capacidade de retenção de água, o nitrogênio básico volátil total e a cor do filé durante o armazenamento congelado. Com base na contagem viável total, parâmetros físico-químicos e qualidade sensorial, pode-se concluir que filés de bagre listrados não tratados ou tratados com extratos de Camellia sinensis (7,63 e 625 µg / mL) podem ser usados ​​por até 18 meses.

Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage / Extrato de chá verde age sobre a qualidade de filés de pescado durante o armazenamento por congelamento

ABSTRACT: This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg / mL) and CS 625 (C. sinensis extract 625 µg / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage.

RESUMO: O objetivo deste estudo foi investigar os efeitos do extrato de folhas de chá verde (Camellia sinensis) na qualidade de filés de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 ± 2 ° C). O estudo incluiu três tratamentos: imersão dos filés de bagre listrado em água fria da torneira como um tratamento de controle, em solução de extrato de Camellia sinensis 7,63 µg / mL e em solução de extrato de Camellia sinensis 625 µg / mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, três, seis, nove, 12 e 18 meses. Os parâmetros avaliados incluíram contagem viável total, parâmetros físico-químicos (capacidade de retenção de água, nitrogênio básico volátil total, valor de peróxido, substâncias reativas ao ácido tiobarbitúrico, umidade e pH), propriedades sensoriais e medição de cor. Os resultados mostraram que os filés de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidação de lipídios, inibiram o crescimento de bactérias e aumentaram as propriedades sensoriais em comparação com as amostras não tratadas. Além disso, o tratamento do extrato de Camellia sinensis não afetou o pH, a umidade, a capacidade de retenção de água, o nitrogênio básico volátil total e a cor do filé durante o armazenamento congelado. Com base na contagem viável total, parâmetros físico-químicos e qualidade sensorial, pode-se concluir que filés de bagre listrados não tratados ou tratados com extratos de Camellia sinensis (7,63 e 625 µg / mL) podem ser usados ​​por até 18 meses.

Physicochemical Properties and Consumer Acceptance of Hamburgers Processed with Chicken Meat Affected by Wooden Breast Myopathy.

Considering the increased incidence of wooden breast myopathy in broilers, the intake involves no threat to human health, indefinite etiology consumer rejection by appearance in such breasts, and the lack of studies on the industrial use of wooden breast. The objective of this study was evaluating the quality of hamburgers made with chicken meat affected by wooden breast. Breast samples from broilers slaughtered at 48-days-old were used. Normal (absence of myopathy), moderate degree (hardness only in one region of the breast) and severe degree (hardness over the entire length of the breast) samples were processed for the manufacture of hamburgers whose quality analyses (color, pH, cooking weight loss, shrinkage percentage, tenderness, storage weight loss, water activity, lipid oxidation, chemical composition and consumer test) were performed on non-stored samples (Day 0), and after storing at 30, 60, 90 and 120 days at -20 °C. There was a reduction (p < 0.05) in tenderness in samples of moderate-grade hamburgers (from 161.45 N to 289.40 N) after 120 days of storage. Hamburgers produced with chicken breast samples affected by wooden breast myopathy presented higher (p < 0.0001) fat concentration (5.32 g/100 g and 5.26 g/100 g, respectively, for the moderate and severe degree) than hamburgers made of normal samples (4.45 g/100 g). Lipid oxidation values increased, which exceeded the limit of rancidity detection, independent of myopathy. The consumers equally appreciated the aroma, flavor, and texture, and rated their overall acceptance as similar regardless of the quality of chicken meat. Chicken breast hamburgers with wooden breast myopathy is a viable alternative for the poultry industry.

Effect of the antioxidants composition in diet on the sensory and physical properties of frozen farmed Coho salmon (Oncorhynchus kisutch).

BACKGROUND: Great attention has been paid to the antioxidants present in farmed fish feeds, with the replacement of synthetic antioxidants by natural ones being a main objective. In the present study, Coho salmon (Oncorhynchus kisutch) was fed a conventional diet that was enriched with different kinds of antioxidants: synthetic antioxidants (butylated-hydroxy toluene and ethoxyquin; diet I), a tocopherols-rich mixture (diet II) and a tocopherols-rosemary extract mixture (diet III). A comparative study of the sensory and physical changes observed in the corresponding frozen products was undertaken. RESULTS: After 18 months at -18 °C, fish previously fed on diet I showed higher putrid and rancid odours and rancid taste scores, while lower mean typical odour and taste values were attained. Dripping and expressible moisture values obtained for diet II-fish were lower when compared with their counterparts belonging to the diet I; additionally, microstructure analysis revealed that Z-lines integration was better preserved in fish corresponding to diets II and III. CONCLUSION: Diet II has been recognised as being the most profitable to be employed to maintain the sensory and physical properties of the frozen product when long-term storage is considered. Further research is to be continued to optimise the natural antioxidants profile.

Comparison of fatty acid content of fresh and frozen fillets of rainbow trout (Oncorhynchus mykiss) Walbaum

The aim of this study was to evaluate and compare the percentage content of fatty acids (FA) of 54 rainbow trout fresh and frozen fillets. Frozen fillets were stored at -15ºC for 45 and 90 days. Saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA), omega-6 (n-6) and omega-3 (n-3) fatty acids were determined by gas chromatograph coupled to mass spectrometry. The results indicated that during frozen storage, SFA and MUFA content increased by 32.63 and 9.25%, respectively, while PUFA content decreased by 25.3%, n-6 by 12.4% and n-3 by 32.55%. These changes were more significant (P ≤ 0.05) during the first 45 d of storage. It was concluded that the frozen storage had a negative impact on meat quality of rainbow trout due to the reduction of PUFA, n-3/n-6, polyene index and PUFA/ SFA and the increase of the SFA, and atherogenic and thrombogenic indexes, which meant a substantial loss of nutritional value in the fillets of rainbow trout.

Effect of refrigeration and frozen storage on the campylobacter jejuni recovery from naturally contaminated broiler carcasses

Campylobacter jejuni is the most common thermophilic Campylobacter associated with human enteritis in many countries. Broilers and their by-products are the main sources for human enteritis. Refrigeration and freezing are used to control bacterial growth in foods. The effect of these interventions on survival of Campylobacter jejuni is yet not quite understood. This study evaluated the effect of storage temperature on the survival of C. jejuni in chicken meat stored for seven days at 4ºC and for 28 days at -20ºC. The influence of selective enrichment on recovery of Campylobacter was also evaluated. Thirty fresh chicken meat samples were analyzed and 93.3 percent was contaminated with termotolerant Campylobacter spp. with average count of 3.08 Log10 CFU/g on direct plating. After refrigeration, 53.3 percent of the analyzed samples tested positive for Campylobacter and the average count was 1.19 Log10 CFU/g. After storage at -20ºC, 36.6 percent of the samples were positive with a verage count of 0.75 Log10 CFU/g. C. jejuni was detected after enrichment, respectively, in 50 percent of the fresh, 36.7 percent of the refrigerated and 33.3 percent of the frozen meat samples analyzed. No difference was detected for the recovery of C. jejuni from fresh, refrigerated or frozen samples after selective enrichment, showing that this microorganism can survive under the tested storage conditions.

Effect of refrigeration and frozen storage on the Campylobacter jejuni recovery from naturally contaminated broiler carcasses.

Campylobacter jejuni is the most common thermophilic Campylobacter associated with human enteritis in many countries. Broilers and their by-products are the main sources for human enteritis. Refrigeration and freezing are used to control bacterial growth in foods. The effect of these interventions on survival of Campylobacter jejuni is yet not quite understood. This study evaluated the effect of storage temperature on the survival of C. jejuni in chicken meat stored for seven days at 4°C and for 28 days at -20°C. The influence of selective enrichment on recovery of Campylobacter was also evaluated. Thirty fresh chicken meat samples were analyzed and 93.3% was contaminated with termotolerant Campylobacter spp. with average count of 3.08 Log10 CFU/g on direct plating. After refrigeration, 53.3% of the analyzed samples tested positive for Campylobacter and the average count was 1.19 Log10 CFU/g. After storage at -20°C, 36.6% of the samples were positive with a verage count of 0.75 Log10 CFU/g. C. jejuni was detected after enrichment, respectively, in 50% of the fresh, 36.7% of the refrigerated and 33.3% of the frozen meat samples analyzed. No difference was detected for the recovery of C. jejuni from fresh, refrigerated or frozen samples after selective enrichment, showing that this microorganism can survive under the tested storage conditions.

Effect of refrigeration and frozen storage on the Campylobacter jejuni recovery from naturally contaminated broiler carcasses

Campylobacter jejuni is the most common thermophilic Campylobacter associated with human enteritis in many countries. Broilers and their by-products are the main sources for human enteritis. Refrigeration and freezing are used to control bacterial growth in foods. The effect of these interventions on survival of Campylobacter jejuni is yet not quite understood. This study evaluated the effect of storage temperature on the survival of C. jejuni in chicken meat stored for seven days at 4ºC and for 28 days at -20ºC. The influence of selective enrichment on recovery of Campylobacter was also evaluated. Thirty fresh chicken meat samples were analyzed and 93.3% was contaminated with termotolerant Campylobacter spp. with average count of 3.08 Log10 CFU/g on direct plating. After refrigeration, 53.3% of the analyzed samples tested positive for Campylobacter and the average count was 1.19 Log10 CFU/g. After storage at -20ºC, 36.6% of the samples were positive with a verage count of 0.75 Log10 CFU/g. C. jejuni was detected after enrichment, respectively, in 50% of the fresh, 36.7% of the refrigerated and 33.3% of the frozen meat samples analyzed. No difference was detected for the recovery of C. jejuni from fresh, refrigerated or frozen samples after selective enrichment, showing that this microorganism can survive under the tested storage conditions.

Influence of washing and frozen storage on the myofibrillar protein fraction in sardine mince flesh

El almacenamiento congelado de especies pesqueras, como la sardina, resulta en cambios significativos en sus propiedades funcionales las cuales determinan su tiempo de vida en almacenamiento. La pulpa de sardina se caracteriza por un alto contenido de grasa, músculo oscuro, y proteínas sarcoplasmáticas que inhiben la formación de geles a base de esta pulpa. Aplicando tratamiento de lavado a la pulpa de sardina se remueven compuestos indeseables para la preparación de productos a base de esta pulpa y a la vez aumentando su tiempo de vida en anaquel. El objetivo del presente estudio fue evaluar el efecto del almacenamiento en congelación a –30°C sobre la fracción de las proteínas miofibrilares de la pulpa de sardina tratada con soluciones al 0,5 por ciento de bicarbonato de sodio. Lotes de pulpa de sardina se le aplicó tratamiento de lavado con una solución de bicarbonato de sodio al 0,5 por ciento y luego centrifugadas a 300 rpm por 15 min. para la eliminación del agua remanente. Lotes de 100 gr. fueron empacados en bolsas de polipropileno y almacenadas a –30°C y analizadas cada 30 días durante150 días. Las proteínas nmiofibrilares fueron extraídas con buffer fosfato (tris HCl, KCl, EDTA, pH 7,6), y evaluadas por la técnica de electroforesis, SDS-PAGE. Las bandas de las diferentes proteínas y sus productos de degradación fueron analizadas y digitalizadas utilizando un Gel Doc 2000 y un programa Quality One 4.1.1 de Bio-Rad. Las principales bandas y sus productos de degradación fueron identificados por comparación de estos contra un estándar de peso molecular. A los 60 días se observó el comienzo del deterioro de las proteínas miofibrilares con pesos moleculares aparentes entre 220 y 65KD, y la formación de agregados moleculares de alto peso molecular. A los 120 días este deterioro se hace más pronunciado apareciendo gran cantidad de bandas de bajo peso molecular, péptidos, los cuales incrementan a medida que transcurre el tiempo de almacenamiento congelado...

Frozen storage of fish species, such as sardine, result in detrimental changes in functional properties that determine storage life. Sardine meat is characterized by high fat content, dark meat, and sarcoplasmic proteins that inhibit gel formation. Washing mince flesh with solutions such as sodium bicarbonate is very effective for removing undesirable components. The objective of this research was to study the effects of frozen storage at -30°C in the myofibrillar protein fraction of sardine mince flesh washed with 0.5% sodium bicarbonate solution. Samples of sardine-minced flesh were washed three times with a 0.5% of sodium bicarbonate solution and centrifuged at 3000 rpm for 15 minutes. These samples were divided in lots of 100 g. packed in plastic bags and stored at -30°C, and analyzed every 30 days for 150 days. The myofibrillar proteins were extracted using a phosphate buffer (tris HCl, KCl, EDTA, pH 7.6), and evaluated by SDS-PAGE. The bands were analyzed and digitalized with a Gel Doc 2000 and Quality One 4.1.1 by Bio-Rad. The main bands of myofibrillar protein were identified by comparison of these against a prestained molecular weight standard. After 60 days there was deterioration of the myofibrillar protein fraction with apparent molecular weight between 220 and 65KD, and the formation of molecular aggregates at high molecular weight occurred. After 120 days due to myofibrillar protein deterioration, protein and peptides with low molecular weight were formed and increasing throughout frozen storage. Understanding the mechanism involved in the deterioration of the mince flesh during frozen storage we would enable to help the establishment of quality parameters and ability to predict storage life for that product.

Estabilidad de filetes de sardina (Sardinella aurita) en almacenamiento congelado a -18ºC / Stability of Sardine Fillets (Sardinella aurita) under Frozen Storage at -18°C

Los cambios físicos, químicos y sensoriales fueron evaluados en filetes de sardina (Sardinella aurita), almacenados en congelación a -18°C por seis meses. Se tomaron muestras mensualmente con el propósito de determinar: pH, color (L, a y b), líquido exprimible (LE), solubilidad de proteínas solubles en soluciones salinas (SPs), ácido tiobarbitúrico (TBA), ácido láctico, perfil de ácidos grasos, humedad y evaluación sensorial. En este estudio el tiempo de almacenamiento mostró diferencias significativas (P < 0,05) con respecto a: color (L, a y b), evaluación sensorial, SPs y LE. La evaluación sensorial resultó ser el parámetro más idóneo para medir la estabilidad de los filetes congelados, los cuales mostraron un excelente grado de frescura, hasta el segundo mes de almacenamiento a partir del cual comienza a decrecer, pero conservando buenas condiciones sensoriales hasta el quinto mes. Al sexto mes se manifestaron alteraciones en el color del músculo, con la aparición de manchas amarillas, debido posiblemente a la oxidación de lípidos. Estos cambios sensoriales fueron confirmados por el índice de TBA, el cual se incrementó de 0,024 (Ab.Und/g), hasta 0,22 al sexto mes. La frescura inicial de las sardinas crudas, su bajo contenido de grasa y una correcta manipulación, fueron los factores que influyeron en la estabilidad del producto final.

Physical, chemical and sensorial changes were evaluated in sardine (Sardinella aurita.) fillets under frozen storage at -18°C for six months. Samples were taken monthly in order to evaluate: pH, colour (L,a, and b), water binding capacity (WBC), solubility of proteins in saline solutions (SPs), thiobarbituric ácid test (TBA), lactic acid, fatty acid profile, moisture and sensory evaluation. In this research the storage time shows significant differences (P < 0.05) with: colour (L,a and b), sensorial evaluation, SPs and WBC. Sensorial evaluation was the most suitable parameter in measurement frozen fillets stability. Fillets showed an excellent grade of freshness, until second month of frozen storage. After that, quality decrease, but also can reach until fifth month, with good sensorial conditions, meanwhile at sixth month, muscle colour was alterate with yellow spots, maybe due by lipid oxidation. These sensorial changes were confirmed by TBA index, which increase from 0.024 (Ab.Und/g) at the beginning of this experience, until 0.22 al sixth month. The initial freshness of raw sardine, the low fat level (2.5%), and good manipulation were important factors that influence in the stability of the end product.