Sous vide cooking improved the physicochemical parameters of hot-boned bovine semimembranosus muscles.

The physicochemical parameters of hot-boned bovine semimembranosus muscles after sous vide cooking were investigated. Hot-boned or wet-aged steaks were collected, and cooked by different cooking methods, including sous vide (57 °C, 11 h, SV), grilling (at 200 °C to the central temperature of 72 °C, GR) or boiling (100 °C, 2 h, BO). The meat color, tenderness, water-holding capacity, degree of oxidation, myoglobin denaturation and sensory quality traits were determined, as well as the changes in the microstructure. Compared to other cooking methods, SV reduced the degree of oxidation and muscle shortening, and significantly improved the water holding capacity (WHC), tenderness, connective tissue content and overall acceptability for both hot-boned and wet-aged steaks. The oxidation and muscle shortening were reduced in hot-boned SV steaks (P < 0.05), and the water-holding capacity and sensory scores for juiciness, connective tissue content and overall acceptability were increased (P < 0.05) compared to the wet-aged steaks. The combination of hot-boning and SV cooking resulted in an acceptable tenderness, better overall sensory acceptability and higher WHC than other combinations of muscle states and cooking methods. Therefore, it is a good choice to cook hot-boned semimembranosus muscles using SV to improve the eating quality, which can eliminate the need for aging, benefiting the beef industry.

Effects of dietary resveratrol supplementation in cattle on the anti-oxidative capacity and meat quality of beef steaks under high­oxygen packaging.

The effects of dietary resveratrol supplementation on beef quality and antioxidant capacity under high­oxygen packaging were studied. Twelve cattle were selected and fed a total mixed ration (Control, CON) or supplemented with resveratrol (5 g/cattle/day, RES) for 120 days. The antioxidant capacity and meat quality of beef under high­oxygen modified atmosphere packaging (HiOx-MAP, 80%O2/20%CO2) and overwrap packaging (OW) were evaluated during storage. Compared to the CON, RES enhanced antioxidant enzyme activity in serum and muscle, and increased the expression of Nrf2 and its downstream target genes (P < 0.05), which decreased the lipid and protein oxidation of steaks during storage (P < 0.05). The RES resulted in a* values increasing throughout storage (P < 0.05) and lower MetMb% than CON steaks (P < 0.05) in HiOx-MAP. The water-holding capacity (WHC) was improved and Warner-Bratzler shear force (WBSF) was reduced (P < 0.05) in RES steaks during storage. Thus dietary resveratrol increased beef antioxidant capacity under HiOx-MAP and improved meat quality, and can be used as a potential method to elevate beef quality and reduce the oxidation under HiOx-MAP.

Influence of oxygen concentration on the fresh and internal cooked color of modified atmosphere packaged dark-cutting beef stored under chilled and superchilled conditions.

The current research evaluated the combined effect of oxygen concentration (20%, 50% and 80% O2) and storage temperature (4°C or -1.5°C) on the fresh and internal cooked color of dark-cutting (DC) beef. Steaks were packaged in modified atmosphere packaging (MAP) over a 12-day storage period. Although the metmyoglobin reducing activity (MRA) of DC steaks decreased with increasing O2 levels, lower oxygen consumption (OC) and deeper oxygen penetration depth (OPD) improved the surface color of 50%O2-MAP and 80%O2-MAP DC steaks. 80%O2-MAP resulted in the highest (P < 0.05) percentage myoglobin denaturation and alleviated the phenomenon of persistent pink (PP) observed in DC beef. Compared with normal chilling, superchilling significantly increased the redness values of DC steaks through inhibition of lipid oxidation and enhancement of MRA, while it had no effects on PP due to the limited OPD. The results suggest that 80%O2-MAP combined with superchilling can be used to improve fresh color and minimize PP of DC beef.

Effects of Calcium Salts on the Physicochemical Quality of Cured Beef Sausages during Manufacturing and Storage: A Potential Calcium Application for Sausages with Alginate Casings.

The impacts of adding calcium chloride (CaCl2) and calcium lactate (CaLac) with different concentrations (0%, 0.2%, 0.4%, and 0.7%) on the physicochemical properties of cured beef sausages were investigated in this study. Meat color, pH, lipid oxidation, and cooking loss were measured at respective manufacturing stages (ground beef, raw chopped batter, and after cooking). Additionally, meat color, pH, lipid oxidation, nitrosylhemochrome, residual nitrite, and texture profiles of vacuum-packaged sausages were evaluated during seven days of storage. Compared with the control (no Ca added), both calcium salts resulted in deteriorative color and texture properties, and promoted pH decline, cooking loss, and lipid oxidation of sausages during manufacturing and storage. However, increased calcium salt addition led to the reduction of residual nitrite over time. Compared to CaCl2 addition, 0.2-0.4% CaLac resulted in greater redness and oxidative stability and softer texture. These results may be useful when considering calcium salt additions in sausages, for the purpose of co-extruded sausages coated with alginate where Ca salts are used to form the casing during the co-extrusion of the sausages.

Protein degradation and structure changes of beef muscle during superchilled storage.

This study investigated the effect of superchilled storage (-4 °C) on protein degradation and structural changes of beef steaks from M. longissimus lumborum compared with traditional chilling (2 °C) and frozen storage (-18 °C). Traditional chilling induced significantly greater degradation of troponin T and desmin, and more rapid loss of calpain activity, compared to superchilled or frozen storage treatments. The proteolysis of key myofibrillar proteins resulted in a sharp decline of WBSF values during traditional chilled storage. For frozen beef samples, no major changes were observed with respect to protein degradation or muscle structure during storage. However, superchilled samples exhibited wider gaps between muscle fibers at 12 weeks storage, associated with muscle fiber shrinkage.

A Casparian strip domain-like gene, CASPL, negatively alters growth and cold tolerance.

A cold-induced transcript encoding a Casparian strip membrane domain (CASP)-like protein (ClCASPL) was identified in watermelon (Citrullus lanatus). Fluorescence microscopy analysis showed that ClCASPL-GFP is localized in the plasma membrane. The orthologous gene in Arabidopsis thaliana (AtCASPL4C1) was also found to play an important role in cold tolerance. Expression analysis using a ß-glucuronidase (GUS) reporter reveals that AtCASPL4C1 is widely expressed in a variety of organs and is cold inducible. Analysis of AtCASPL4C1 T-DNA knock-out plants showed altered growth dynamics, faster growth, increased biomass (dry weight) and earlier flowering compared to wild type (Col-0) and ClCASPL overexpressing plants. AtCASPL4C1 knock-out plants showed elevated tolerance to cold stress, while overexpressing CICASPL resulted in increased sensitivity to cold stress in Arabidopsis. Interestingly, AtCASPL4C1 knock-out plants did not display significant alterations in the Casparian strip formation in roots. Thus, the combination of these results suggests a role for CICASPL and AtCASPL4C1 beyond Casparian strip formation in roots, possibly indicating a more fundamental role in vascular tissue.

Identification of miRNAs and their targets using high-throughput sequencing and degradome analysis in cytoplasmic male-sterile and its maintainer fertile lines of Brassica juncea.

BACKGROUND: Regulatory network of cytoplasmic male sterility (CMS) occurrence is still largely unknown in plants, although numerous researches have been attempted to isolate genes involved in CMS. Here, we employed high-throughput sequencing and degradome analysis to identify microRNAs and their targets using high-throughput sequencing in CMS and its maintainer fertile (MF) lines of Brassica juncea. RESULTS: We identified 197 known and 78 new candidate microRNAs during reproductive development of B. juncea. A total of 47 differentially expressed microRNAs between CMS and its MF lines were discovered, according to their sequencing reads number. Different expression levels of selected microRNAs were confirmed by using real-time quantitative PCR between CMS and MF lines. Furthermore, we observed that the transcriptional patterns of these microRNAs could be mimicked by artificially inhibiting mitochondrial F1F0-ATPase activity and its function in MF line by using treatment with oligomycin. Targeted genes of the microRNAs were identified by high-throughput sequencing and degradome approaches, including auxin response factor, NAC (No Apical Meristem) domain transcription factor, GRAS family transcription factor, MYB transcription factor, squamosa promoter binding protein, AP2-type transcription factor, homeobox/homeobox-leucine zipper family and TCP family transcription factors, which were observed to be differentially expressed between CMS and MF. CONCLUSION: Taken together, from these findings we suggested microRNA might participate in the regulatory network of CMS by tuning fork in gene expressions in CMS B. juncea. The differential expression of miRNAs observed between CMS and MF lines suggested that biogenesis of miRNAs could be influenced in the CMS.