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One of the key points in the frozen food processing is thawing with minimal damage to the quality. Since the commonly used methods for thawing of foods are slow and reduce the quality of the product, application of an efficient method seems necessary. In this research, thawing of tuna fish was performed by immersion ohmic method. Thawing rate roles a vital key in the quality and significantly increased by ohmic (0.2 g / s , the mean of ohmic group) in comparison with conventional thawing (0.15 g / s , the mean of conventional group) methods. Immersion ohmic thawing increased rate of thawing about 5 times. Parameters important in quality such as T-VBN, protein solubility, thawing evaporation loss, pH, thawing loss and press juice were measured. Group analyses showed significant difference between ohmic and conventional treatment in protein solubility, thawing evaporation and thawing loss (p < 0.05). [ABSTRACT FROM AUTHOR]

• Microwave, ultrasonic and infrared were applied to defrost different types of meat. • Physical field thawing was better in maintaining texture and nutrition of meat. • Ultrasonic thawing showed the best effects. The effects of thawing frozen meats using physical field-based methods and traditional thawing methods on frozen meat were examined is a critical analysis of relevant literature. Based on published data it can be concluded that physical field thawing methods reduce thawing cooking losses and retain color and texture of the thawed meat. Compared with meat samples thawed at room temperature, the loss due to ultrasonic thawing of pork, beef and mutton was lower by about 43%, 45% and 43%, respectively. The corresponding cooking loss decreased by 8.1%, 7.5% and 10.10%, respectively, under the test conditions. The results of MMb content and TBARS indicates that physical field thawing reduces protein and lipid oxidation of meat. Compared with the room temperature thawing group, the MMB content of the ultrasonic thawing group decreased by 10.13%, 15.70% and 12.69%, while the TBARS value of the ultrasonic thawing group was also the lowest, which decreased by 14.58%, 15.20% and 15.87% compared with the room temperature thawing group. LF-NMR results show that the ultrasonic thawing has the highest content of bound water and immobilized water. These results indicate that the physical field thawing methods can better maintain the quality of meat samples. Among different thawing methods tested ultrasonic thawing showed the best effects. [ABSTRACT FROM AUTHOR]

Adipose (fat) tissue has different physical properties from skeletal muscle tissue, and its moisture content is relatively low; thus, freezing or freeze-thawing of meat affects its quality. However, the effect of intramuscular fat (IMF) of meat has not been comprehensively studied. The changes in the meat quality and muscle fiber characteristics of beef striploin (M. longissimus lumborum ; LL) with different IMF contents (63.5 g/kg‒260.3 g/kg; n = 52) following freeze-thawing were examined. Freeze-thawing destroyed muscle fibers, and the fiber size was decreased irrespective of muscle fiber type or IMF content. However, the size of type I and IIA muscle fibers was largely altered in LL muscles with lower IMF content. Low IMF content increased the tenderness and decreased the pH of LL muscles; the effects of low IMF content on discoloration in LL muscles were less prominent. Larger IMF particles and higher density were associated with reduced thawing loss in LL muscles. IMF content reduced the lightness of frozen-thawed meat, but it did not excessively reduce water-holding capacity and pH. Thus, deterioration in meat quality can be prevented by considering the IMF content during the freezing process. [Display omitted] • Intramuscular fat reduces muscle tissue destruction in frozen-thawed beef. • Intramuscular fat mitigates reduction of thawing loss of frozen-thawed beef. • Lower fat content associated with improved meat tenderness. • Intramuscular fat increases discoloration of frozen-thawed meat. [ABSTRACT FROM AUTHOR]

Freezing and thawing occur during storage, transportation, and retail display, leading to deterioration of frozen shrimp. The objective of this research was to investigate the change in quality of frozen white shrimp treated by lysine and NaHCO3 after multiple freeze–thaw cycles. Shrimp were soaked in lysine and lysine/NaHCO3 each at 1% (w/v) frozen in an air‐blast freezer at −30 °C, and kept in a chest freezer (−18 ± 2 °C) for a week before they were thawed using tap water before the analysis (freeze–thaw cycle 1). The samples were subjected to five freeze–thaw cycles, which were repeated every week. Qualities of the samples were determined for thawing loss, cutting force, and total volatile basic nitrogen (TVB‐N), as well as oxidation stability by using Rancimat. The use of lysine/NaHCO3 could significantly reduce thawing loss at all freeze–thaw cycles compared to the control and lysine treatment (P < 0.05). Similar results were found with TVB‐N and the oxidation stability of the samples. A difference in cutting forces of the shrimp between lysine and lysine/NaHCO3 treatment was found when the frequency of freeze–thawing was increased to three cycles; it was lower than that in the control at all cycles. Histological study showed that the treatment with lysine/NaHCO3 led to the swelling of muscle fibers and fewer fragments at five freeze–thaw cycles. The results showed that lysine/NaHCO3 could effectively retard the quality loss from repeated freeze–thawing during frozen storage. Practical Application: Repeated freezing and thawing usually occur during storage, transportation, retail display or in restaurants, and in consumers' kitchens. The temperature at the manufacturing site and during transportation in a tropical country like Thailand is relatively high, and frozen food producers come across quality deterioration resulting from multiple freeze–thaw cycles occurring during transportation and storage. Frozen shrimp producers require research to improve product quality by adding nonphosphate food additives or, if possible, by using natural food ingredients instead of polyphosphate or sodium bicarbonate. [ABSTRACT FROM AUTHOR]

Low voltage electric field (LVEF) thawing has been shown to be an effective method of thawing. In this study, chicken breast meat was thawed in a fixed electric field voltage (2.5 KV), and the thawing process was divided into two stages: stage Ⅰ (−20 °C to −5 °C) and stage Ⅱ (−5 °C to −1 °C). The effects of two-stage air thawing based on low voltage electric field (TLT) on the quality of chicken breast were investigated by altering the thawing temperature (T 1 and T 2) in two stages. The results showed that TLT could significantly (P＜ 0.05) reduce thawing time and thawing loss than air thawing. Among them, TLT22.5–7.5 samples almost retained the same tissue structure as fresh chicken breast, allowing the muscle fibers/bundles to capture more immobile water. TLT22.5–7.5 samples not only kept the color similar to fresh meat, but also had an obviously better moisture correlation characteristic than other thawed samples. TLT also demonstrated a strong microbial reproduction inhibitory impact. The thawed chicken could obtain a comparatively fresh quality if T 2 was kept below 15 °C. Therefore, TLT is expected to reduce total thawing time and prevent meat quality deterioration caused by the freezing and thawing process. • Two-stage LVEF thawing could effectively reduce the thawing loss of chicken breast compare with air thawing. • The moisture distribution of chicken breast thawed by TLT22.5–7.5 was close to fresh meat. • Chicken breast maintained high structural integrity after TLT22.5–7.5 treatment. • Two-stage LVEF thawing showed a stronger microbial reproduction inhibitory impact. [ABSTRACT FROM AUTHOR]

This research aimed to investigate the effects of pigskin gelatin hydrolysate (PGH) on the quality changes of longissimus lumborum (LL) muscles during freezing. The samples were firstly assigned into six groups, including control, sucrose and sorbitol group (SUSO) as positive control, 0%, 1%, 2% and 4% PGH group. The thawing loss of frozen meat, microscopic observation of ice crystal formed during freezing, myowater mobility in muscle tissues, and protein structure changes were determined. PGH reduced the thawing loss of frozen meat by 5.32%. Microscopic observation showed that ice crystal area reduced to 15.54% with 4% PGH treatment. The PGH also reduced the loss of immolized water in meat during freezing. The Raman spectra showed that the protein structure remained more intact in the group of 4% PGH. It can be concluded that the addition of PGH effectively diminished the deterioration of muscle qualities, enhanced the cryoprotective of the muscles during freezing, and this enhancement was associated with their increasing amount. • Pigskin gelatin hydrolysate (PGH) significantly reduced thawing loss of raw porcine meat during freezing. • PGH could reduce the water mobility in raw porcine meat. • PGH maintained the integrality of protein during freezing. • The addition of 4% PGH exhibited the best cryoprotection ability during freezing. [ABSTRACT FROM AUTHOR]

Abstract: Effects of air-blast freezing and cryogenic freezing, thawing by microwave and refrigerator, and freeze–thaw cycle on changes in thiobarbituric acid (TBA), salt-soluble protein (SSP), %freezing loss (%FL), %thawing loss (%TL) and cutting force (CF) of tiger shrimp (Penaeus monodon) were investigated. Air-blast freezing was done at −28±2°C and air velocity of 4–8m/s while cryogenic freezing was done at −70 to (−100) °C. Shrimps frozen at the air velocity of 6m/s had the least %FL and similar CF to the fresh samples. Thawing method did not affect SSP and CF. Samples thawed by the microwave had higher TBA than those in refrigerator. Increasing the freeze–thaw cycle increased the TBA and CF but decreased the SSP. Combined effect of thawing method and freeze–thaw cycles affected %TL only. The histological examination of cryogenic-frozen shrimps showed an increase in spacing between the muscle fiber and torn muscle fiber bundles as the number of freeze–thaw cycles increased. [Copyright &y& Elsevier]

Five hundred broiler males were grown to 56 d and processed under common terms. Front halves were deboned 24 h postmortem to obtain breast fillets, and CIELAB light reflectance was measured on the skin side of each fillet 24 h later. All fillets were bagged and frozen (-20° C) for 5 ma Then the fillets exhibiting the lowest (dark), median (normal), and highest (pale) L* values 48 h postmortem were thawed (3 d at 4°C) and cooked (internal temperature 80°C). Thawing reduced the L* value in the pale fillets and increased it in the dark ones, and cooking further increased L* value and reduced the differences in L*, a*, and b* between groups. Thawing and cooking losses were not affected by initial L* value until they were combined. Total losses increased with initial L*, which was in parallel with a lower increase in thickness after cooking. [ABSTRACT FROM AUTHOR]

Eight hundred broiler males were grown to 56 d and processed under common terms while maintaining individual identity. Front halves were deboned 24 h postmortem (PM) to obtain breast fillets, and CIELAB light reflectance was immediately measured on the skin side of each fillet. Fillets were bagged and held at 4°C for 24 h, and then 20 fillets exhibiting the darkest (47.3 to 57.5), lightest (71.1 to 76.4), and median (63.7 to 64.0) L&ast; values were selected and trimmed to best define the pectoralis major. Remeasurement of light reflectance at 48 h PM revealed decreased L&ast; values solely associated with fillets having the highest L&ast; at 24 h. One-half of the fillets representing each category was frozen (4 d at -20°C) and thawed (3 d at 4°C). The L&ast; value, after thawing, decreased from the 48 h PM value, which equivalently occurred in for all L&ast; categories. Although 48 h PM fillets from each L&ast; category were of similar weights, their lengths and widths increased with L&ast; value. Exudate lost with thawing increased with L&ast; value and paralleled decreases in length and width to equalize dimensions among sources. [ABSTRACT FROM AUTHOR]

Descriptive sensory profiling was carried out to evaluate warmed-over flavour (WOF) development in cooked, chill-stored and reheated pork patties derived from the meat (Musculus longissimus dorsi) of carriers (RN−/rn+) and non-carriers (rn+/rn+) of the RN− gene. Patties were oven-cooked at 150 and 170 °C and chill-stored for up to 5 days to facilitate warmed-over flavour (WOF) development. In addition, thawing losses, cooking losses, pH and TBARS were measured in the cooked pork patties. Analysis of variance (ANOVA) was used to investigate changes in the physical/chemical measurements due to the experimental design variables (storage days, cooking temperature and genotype) and multivariate ANOVA-partial least squares regression (APLSR) was used to determine relationships between the design variables and the sensory and physical/chemical data. WOF was found to involve the development of lipid oxidation derived nuance off-flavour and odour notes, e.g. rancid-like flavour and linseed oil-like odour, in association with a concurrent decrease in ‘meatiness’ as described by, e.g. cooked pork meat-like flavour. Cooking temperature was described by roasted-like and caramel-like odours and samples from carriers of the RN− gene were described as more ‘sour’ and ‘metallic’. Thawing and cooking losses were found to be significantly (P <0.05) higher in meat from carriers of the RN− gene versus non-carriers. pH was negatively related to samples from carriers of the RN− gene. However, the measured pH in RN− carriers could not be significantly ascribed as lower in non-carriers in the freshly cooked meat samples. TBARS were found to be significant (P <0.05) predictors of the sensory terms related to the lipid oxidation aspect of WOF. Moreover, TBARS were significantly (P <0.05) higher in meat from RN− gene carriers but, significantly (P <0.05) lower in meat cooked at high oven temperatures (170 °C). The former effect was postulated as related to pH and the latter as related to the antioxidant effects of Maillard reaction products developed at higher cooking temperatures. Overall, WOF, cooking temperature and genotype were differentiated as individual dimensions through sensory profiling of the meat samples and each source of variation was characterised by specific groups of sensory descriptors. Moreover, the predictive nature of thawing losses, cooking losses and TBARS was established for the effects of RN− gene, cooking temperature and WOF, respectively. [Copyright &y& Elsevier]

Simple Summary: Microalgae synthesize a wide variety of bioactive compounds, such as polysaccharides, PUFAs, and pigments. In addition, microalgae are known for positively influencing growth and intestinal parameters in birds and thus have been contemplated as potential feed additives. Nevertheless, several species widely used in aquaculture have not received much attention in terrestrial animal nutrition. Therefore, in this investigation, we used biomass from Tysochrysis lutea, Tetraselmis chuii, and Porphyridium cruentum to evaluate its safety and usefulness for improving intestinal architecture, body weight, and selected meat quality parameters. Dietary administration of the different biomasses showed positive effects regarding intestinal architecture, which were associated with the observed body weight. Furthermore, the thawing weight loss of fillets decreased after supplementation with T. chuii. Hence, these outcomes suggest that dietary microalgae might be considered as a promising bio-friendly alternative for feed additive production. This pilot investigation aimed at studying the feasibility of using a low dose (0.2%) of dietary microalgae as a means of improving intestinal morphometry, body weight, and selected meat quality parameters in broilers. A total of 72 one-day-old ROSS 308 male chicks were randomly separated into four groups; three experimental pens in which the birds were fed with biomass from Tysochrysis lutea, Tetraselmis chuii, and Porphyridium cruentum over 30 days and a control group. T. chuii and P. cruentum had a positive effect with regard to body weight. In treated animals, duodenal and ileal sections showed characteristic tall and thin villi, with serrated surfaces and goblet cell differentiation. In both sections, values of the villus-height-to-crypt-depth ratio were increased by microalgae ingestion. The thawing weight loss of fillets was reduced in T. chuii-fed animals. The positive effects exerted by T. chuii and P. cruentum on intestinal architecture were associated with the improved body weight. Arguably, these outcomes exhibit the potential of using these species to enhance growth performance in broiler chickens by promoting gut homeostasis and thus nutrient absorption. [ABSTRACT FROM AUTHOR]