Carcass maturity and dicationic salts affect preblended, low-fat, low-sodium restructured beef.

Preblending A- and C-maturity muscles with MgCl(2) and/or CaCl(2) was investigated in low-fat, low-sodium restructured beef. Products were formulated to contain: 1) 80% chunks, preblended 12h with 0.05% MgCl(2), 0.05% CaCl(2), or a combination of each (0.1%) and 0.4% sodium tripolyphosphate (STPP) and 2) 20% mince preblended 12h with 0.05% of each dicationic salt or the combination of dicationic salts (0.1%), 0.4% STPP, and 1.0% NaCl. This formulation achieved a raw product NaCl content of 0.2%. Additionally, a control was formulated with chunks and mince that contained no dicationic salt. CaCl(2) decreased raw and cooked pH and cook yield, and increased cohesiveness; whereas, MgCl(2) increased cook yield and myosin solubility. Total protein solubility was not affected by muscle maturity or dicationic treatment. Myosin solubility of the combination treatment was greater for C-maturity muscle (57 months) compared to A-maturity muscle (20 months) formulations. Control, C-maturity muscle treatments contained more insoluble and total collagen (p < 0.05), and these treatments were more cohesive (p < 0.05) than control, A-maturity treatments. The combination of CaCl(2) and MgCl(2) increased hardness of A-maturity products, but it decreased hardness of C-maturity products. In addition to increasing hardness of A-maturity products, the combination treatment lowered (p < 0.05) cook yield for these products.

Effect of dietary vitamin E supplementation and refrigerated storage on quality of rainbow trout fillets.

Rainbow trout were fed a low vitamin E (200 mg/kg; LVE) or a high vitamin E (5000 mg/kg; HVE) diet for 9 wk to characterize the effect of vitamin E supplementation at 5000 mg/kg on fillet quality. Fish were sampled at 2, 3, 4, 5, 7, and 9 wk of the trial. Fillets were stored at 2 °C for 0, 7, and 14 d, and analyzed for pH, psychrotrophic counts, color, cook yield, shear force, crude fat and moisture content, α-tocopherol, fatty acid composition, and lipid oxidation. There was a significant feeding duration by fillet storage time interaction for psychrotrophic counts, crude fat content, cook yield, and shear force. Fillet L* value was not affected by diet, feeding duration or storage time. Fillet a* was lowest at 14-d storage, and b* values increased with fillet storage time. High vitamin E diet increased fillet α-tocopherol from 33 to 155 mg/kg. High vitamin E decreased palmitic acid and increased linoleic acid and omega-6 fatty acids. Feeding through 9 wk increased the relative proportions of unsaturated, polyunsaturated, and omega-3 fatty acids, and decreased saturated and omega-6 fatty acids. At 0-d storage, HVE diet did not affect thiobarbituric acid-reactive substances (TBARS) at any sampling week, and fasted fish generated fewer TBARS compared to non-fasted fish.

Acidified sodium chlorite solution as an antimicrobial treatment for rainbow trout (Oncorhynchus mykiss) fillets.

Minimizing microbial growth and maintaining overall quality are priorities for intervention strategies that extend the shelf life of fresh, aquatic foods. Four treatments included a control (fresh fillets), water, 50 ppm of acidified sodium chlorite (ASC), and 1,000 ppm of ASC. Fillets were stored at 1 to 2 degrees C for 0, 8, and 15 days. A significant (P < 0.05) interaction between treatment and storage time was observed for psychrotrophic counts. The increase in psychrotrophic counts with storage time was less for fillets treated with ASC, regardless of ASC concentration. Aerobic plate counts were not affected (P > 0.05) by intervention; however, a significant increase in counts was observed during storage (P < 0.05). Fillet pH, moisture, fat, thiobarbituric acid-reactive substances, fatty acid composition, color, cook yield, and shear force were not affected (P > 0.05) by intervention. Thiobarbituric acid-reactive substances decreased (P < 0.05) during storage. Percentages of individual fatty acids were constant, with the exception of C15 and C20:2; they decreased with storage to 15 days. Percent fat, L* (lightness) and b* (yellowness) values, and cook yield increased (P < 0.05) during storage. Fillet pH, moisture, a* (redness) value, and shear force did not change (P > 0.05) with storage to 15 days. Based on these data, 50 ppm of ASC performed equally as well as 1,000 ppm of ASC. The value of ASC is as a decontaminant; however, fillets in this study had low psychrotrophic counts pretreatment (2.3 log CFU/cm2) and posttreatment (2.03 log CFU/cm2), which did not demonstrate ASC's effectiveness as a decontaminant.

Influence of selection for breast muscle mass on myosin isoform composition and metabolism of deep pectoralis muscles of male and female turkeys.

Advances in genetic selection and nutrition have resulted in rapid growth rates and increased muscle mass, predisposing turkeys to muscle disorders such as deep pectoral myopathies and increasing the incidence of pale, soft, and exudative muscle. The objective of this study was to determine if selection for breast muscle mass created an increase in anaerobic capacity of the deep pectoralis muscle. A total of 67, 18-wk-old, male and female turkeys from two male (tom) lines and one female (hen) line were used. Each bird was anesthetized and one deep pectoralis muscle was electrically stimulated via the pectoral nerve. Muscle pH was recorded every 30 s for 4 min of stimulation and every 1 min for a 10-min recovery period. Non-stimulated muscles, contralateral to the stimulated side, were assayed for lactate dehydrogenase (LDH) and glyceraldehyde phosphate dehydrogenase (GAPDH). Myosin isoforms were resolved with SDS-PAGE. Line or gender had no effect on rate of pH decline during or after stimulation. Declines in pH during stimulation were greater than during the recovery period (0.06 vs. 0.02 U/min). The lightweight male line (LM) had the greatest breast muscle mass as a percentage of body weight (P < 0.05) and the greatest LDH [293 mmol nicotinamide adenine dinucleotide (NADH) min(-1)microg(-1); P < 0.0001] and GAPDH (0.4452 mmol NADH min(-1)microg(-1); P < 0.05) activities. Hens had greater percentages breast weight than males (P < 0.05) and a tendency for increased enzyme activities. The LM line had the largest ratio (2.33:1) (P < 0.05) of adult-to-neonatal myosin. Genetic selection for breast muscle mass resulted in an increased ratio of adult-to-neonatal myosin and increased anaerobic capacity. This effect on myosin isoform composition and anaerobic capacity supports handling modifications that are line specific to minimize meat quality defects.

Effects of fish meal protein supplementation on milk yield and composition and blood constituents of dairy cows.

Ten holstein and 10 Ayrshire cows were fed diets containing undegradable intake protein from either fish meal or corn gluten meal. Cows were introduced to diets 10 d before projected calving date and individually fed blended rations until 60 d postpartum. Diets were balanced for NE1, CP, and degradable and undegradable protein. Source of undegradable protein did not affect total or FCM yields, DM intake, or milk protein percentage. Cows on fish meal diets tended to lose less BW than those on the corn gluten meal supplement (5.3 vs. 10.3% loss of initial BW). Fish meal supplementation resulted in decreased milk fat and SNF percentage (3.2 vs. 4.2% and 8.37 vs. 8.65%, respectively), but diet did not affect total milk fat, protein, or SNF yield. Plasma nonesterified fatty acids decreased and serum insulin increased with increasing weeks postpartum but were not affected by diet. In this study, no significant advantage was found to using fish meal as a source of undegradable intake protein and feed cost was higher when it was used.