Effect of phosphate with tumbling on lipid oxidation of precooked roast beef

Hydrolysis of Beef Sarcoplasmic Protein by Dry-Aged Beef-Isolated Penicillium oxalicum and Its Associated Metabolic Pathways

Yanbian cattle have a unique meat flavor, and high-grade meat is in short supply. Therefore, in this study, we aimed to improve the added value of Yanbian cattle low-fat meat and provide a theoretical reference for the subsequent development of an excellent starter. Rump meat from Yanbian cattle was dry-aged and then screened for protease-producing fungi. Three protease-producing fungi (Yarrowia hollandica (D4 and D11), Penicillium oxalicum (D5), and Meesziomyces ophidis (D20)) were isolated from 40 d dry-aged beef samples, and their ability to hydrolyze proteins was determined using bovine sarcoplasmic protein extract. SDS-PAGE showed that the ability of Penicillium oxalicum (D5) to degrade proteins was stronger than the other two fungi. In addition, the volatile component content of sarcoplasmic proteins in the D5 group was the highest (45.47%) and comprised the most species (26 types). Metabolic pathway analysis of the fermentation broth showed that phenylalanine, tyrosine, and tryptophan biosynthesis was the most closely related metabolic pathway in sarcoplasmic protein fermentation by Penicillium oxalicum (D5). Dry-aged beef-isolated Penicillium oxalicum serves as a potential starter culture for the fermentation of meat products.

Selection and quantification of volatile indicators for quality deterioration of reheated pork based on simultaneously extracting volatiles and reheating precooked pork

This study was to screen and quantify characteristic volatiles tied to the quality deterioration of reheated pork via simultaneously reheating (75 °C, 30 min) and collecting headspace volatiles of precooked pork (100 °C, 10 min; stored: 0 °C, 0-14 d) for GC-MS analysis. The concentrations of hexanal (6.05 ± 0.86-12.05 ± 0.44 mg/kg), (E)-2-octenal (1.54 ± 0.16-3.07 ± 0.08 mg/kg), (E,E)-2,4-heptadienal (1.52 ± 0.44-2.58 ± 0.31 mg/kg) and 8 other selected volatiles in reheated pork increased as the storage time of the precooked counterparts increased. The increase rate of hexanal was 2.9-199 times faster than that of other volatiles based on zero-order reaction fitting (R² = 0.876-0.997). Results from clustering analysis of these volatiles were consistent with their formation pathways tied to lipid autooxidation. This simple approach, reheating and collecting volatiles of precooked meat concurrently, introduces a new possibility for standardizing volatile analysis of precooked meats required being reheated before consumption.

Tumbling and subsequent aging improves tenderness of beef longissimus lumborum and semitendinosus steaks by disrupting myofibrillar structure and enhancing proteolysis

Tenderness is an important sensory attribute to the overall eating experience of beef. Identifying novel methods to ensure consistent tenderness, especially in inherently tough cuts, is critical for the industry. This study investigated if tumbling without brine inclusion could be an effective method to improve the quality and palatability attributes of beef longissimus lumborum (LL) and semitendinosus (ST) steaks. Furthermore, interactions with postmortem aging were evaluated to determine how tumbling might affect protein degradation and muscle ultrastructure. At 5 d postmortem, pairs of LL and ST muscles from beef carcasses (n = 16) were bisected, vacuum packaged, and tumbled for 0, 40, 80, or 120 min. Sections were divided and subsequently aged an additional 0 or 10 d at 2 °C. Tumbling for any duration improved instrumental tenderness of LL (P < 0.001) but not ST (P > 0.05) steaks, regardless of aging time. Tumbling exacerbated moisture loss in both muscles shown by greater purge and cooking losses (P < 0.05). Myofibrillar fragmentation was induced through tumbling in both muscles (P < 0.001), which was supported by transmission electron microscopy images. Tumbling for 120 min followed by 10 d of aging resulted in less abundant intact troponin-T in both LL and ST (P < 0.05), as well as less intact desmin in ST (P < 0.05); however, calpain-1 autolysis was not affected by tumbling (P > 0.05). No effects of tumbling, aging, nor the interaction were found for the content and solubility of collagen (P > 0.05). Consumer panelists (n = 120/muscle) rated LL steaks tumbled for any duration higher for tenderness and overall liking compared to control steaks (P < 0.05). For ST, significant interactions were found for consumer liking of tenderness and juiciness. In general, tumbling without subsequent aging resulted in poorer juiciness than non-tumbled (P < 0.05), while at 10 d no differences in juiciness were found between treatments (P > 0.05). For ST steaks that were aged 10 d, 120 min of tumbling resulted in greater tenderness liking than non-tumbled steaks (P < 0.05). These results suggest that tumbling would result in myofibrillar fragmentation and may benefit the degradation of myofibrillar proteins; however, there would be negligible impacts on collagen. Accordingly, tumbling without brine inclusion alone may be sufficient to improve tenderness and overall liking of LL steaks, while combined tumbling with subsequent postmortem aging would be necessary to improve tenderness liking of ST.

Vascular rinsing and chilling effects on meat quality attributes from cull dairy cows associated with the two lowest-valued marketing classes

Commercially harvested cull dairy cow carcasses (n = 64) from the two lowest-valued marketing classes (MC: Lean, LE; Light, LI) were conventionally chilled (CN) or vascularly rinsed with a chilled isotonic substrate solution (Rinse & Chill®; RC). Longissimus lumborum (LL) and Triceps brachii (TB) muscles were processed (steaks, ground). Early postmortem (first 24 h), RC resulted in a lower pH at each time measured. RC steaks had longer sarcomeres and lower shear force than CN. RC produced greater redness associated with blooming and display times. RC LE beef resulted in greater oxymyoglobin during display times. RC ground TB had greater moisture fat-free than CN. RC Lean LL had less purge loss compared to CN LE. RC had greater total pigments than CN. RC ground TB had greater oxygen consumption and lower thiobarbituric acid reactive substances compared to CN. RC has the potential to improve tenderness and color as well as limit lipid oxidation with similar benefits across the two marketing classes.

Chia, Quinoa, and Their Coproducts as Potential Antioxidants for the Meat Industry

Chia and quinoa have gained popularity among consumers worldwide due to the wide variety of nutrients but also to the bioactive compounds that they contain. Lately, their processing has generated different coproducts (non-commercial grains, flour, partially deoiled flour, rich-fiber fraction, and oil, among others), which could be reincorporated to the food chain with important technological properties, antioxidant activity included. Both sets of ingredients have been revealed a great technological potential for meat product development and innovation, taking into account that oxidation is one of the main reactions responsible for their deterioration and shelf life reduction. This review focuses on the antioxidant compounds of chia and quinoa coproducts and on the strategies used to add them to meat products highlighting their effect on the lipid oxidation control. Apart from the different ways in which quinoa and chia can be incorporated into meat products and their antioxidant properties, innovative approaches for increasing this antioxidant effect and counteracting any negative alterations they may cause will be discussed.

Influences of encapsulated polyphosphate incorporation on oxidative stability and quality characteristics of ready to eat beef Döner kebab during storage

The effect of different polyphosphates (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) and ratios of unencapsulated (u) and encapsulated (e) forms of these polyphosphates (PP, 0.5%) on lipid oxidation inhibition and quality characteristics of ground beef döner kebab were evaluated. STP usage provided lower cooking loss (CL) than HMP or SPP (P < .05). Döners containing STP had higher pH than those with HMP or SPP (P < .05). Regardless of ePP ratio in the total added PP (0.5%), added ePP created the same effect on CL and pH as 0.5% uPP in döner samples. The highest orthophosphate (OP) was obtained with STP, followed by SPP, HMP and control (no PP; P < .05). OP values generally decreased with increasing ePP ratio up to 0.4% in the total added PP (P < .05). Thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxide (LPO) in döners containing PP were lower than control (P < .05). The lowest TBARS and LPO were determined in döners containing STP or SPP (P < .05). In general, increasing ePP ratio (up to 0.2% for STP and SPP, and 0.4% for HMP) in the total added PP provided further reduction in TBARS and LPO (P < .05). TBARS and LPO results suggested that ePP incorporation may be strategic implementation for meat industry to control lipid oxidation in ready to eat döner kebab.

Quality Characteristics of Samgyetang according to the Sodium Chloride Level and with/without Phosphate in Broth

In this study, the effect of sodium chloride (salt) concentration and phosphate on the quality properties of samgyetang was investigated. Increasing the salt concentration by 0.5% increased the moisture and ash content, salinity, water holding capacity (WHC), and thiobarbituric acid reactive substances (TBARS), whereas the protein content, pH, cooking losses, and shear forces were decreased. Addition of phosphate to the brine increased the pH and WHC, but decreased the TBARS, cooking losses, and shear forces. In a sensory evaluation, the scores for flavor and overall acceptability were the highest when the salt concentration of the brine was 2.0%. Overall, this study shows that the salt concentration and addition of phosphate to the brine of samgyetang substantially influences the overall quality of the chicken breast. Based on quality measurements and sensory scores, a 2.0% salt concentration with the addition of phosphate appear to be the most suitable conditions for the manufacturing of marinated samgyetang.

Impact of Added Encapsulated Phosphate Level on Lipid Oxidation Inhibition during the Storage of Cooked Ground Meat

The effect of levels (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) of added encapsulated (e) phosphate (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) on lipid oxidation inhibition during storage (0, 1, and 7 d) of ground meat (chicken, beef) was evaluated. The use of eSTP and eSPP resulted in lower and higher cooking loss (CL) compared to eHMP, respectively (P < 0.05). Increasing encapsulated phosphate level (PL) enhanced the impact of phosphates on CL in both chicken and beef samples (P < 0.05). Encapsulated STP increased pH, whereas eSPP decreased pH (P < 0.05). pH was not affected by PL. The highest orthophosphate (OP) was obtained with eSTP, followed by eSPP and eHMP (P < 0.05). The level of OP determined in both chicken and beef samples increased (P < 0.05) during storage. Increasing PL caused an increase in OP (P < 0.05). The highest reduction rate in the formation of thiobarbituric acid reactive substances (TBARS) and LPO for both meat species were obtained with eSPP, followed by eSTP and eHMP (P < 0.05). Increasing PL resulted in lower TBARS and LPO (P < 0.05). Findings suggest that encapsulated phosphates can be a strategy to inhibit lipid oxidation for the meat industry and the efficiency of encapsulated phosphates on lipid oxidation inhibition can be enhanced by increasing PL.

The effects of tumbling and sodium tripolyphosphate on the proteins of döner

This study was designed to investigate the influence of tumbling and sodium tripolyphosphate (STPP) with marination on the protein structure of raw and cooked döner, a traditional Middle East product consumed widely in many areas of the world. Proximate composition (%moisture, %protein, %fat, %ash, and pH value), salt soluble protein (SSP) and total α-amino grup amount were determined. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to investigate alterations in the sarcoplasmic and myofibrillar proteins. Utilization of STPP increased the moisture content and ash contents, and pH value of raw döner (p<0.05). Only tumbling and STPP had a significant two-way interaction for moisture content, SSP and total α-amino group amounts of cooked döner (p<0.05). None of the treatments significantly affected the fraction of sarcoplasmic and myofibrillar proteins. In addition, cooking caused proteolysis of these proteins.

Lipid and protein oxidation of chicken breast rolls as affected by dietary oxidation levels and packaging

The objective of this study was to determine the effects of dietary treatment and packaging on the oxidative stability of breast rolls. A total of 120 4-wk-old broiler chickens were randomly assigned to control, oxidized diet (5% oxidized oil, PV = 100), or antioxidants-added diet (500 IU vitamin E + 200 ppm BHA) and fed for 2 wk. Breast muscles were separated from the carcasses and breast rolls were prepared. The rolls were cooked in a smoke house (85 °C) to an internal temperature of 74 °C, cooled, sliced to 2-cm thick pieces, individually packaged in oxygen permeable bags or vacuum-packaged in oxygen impermeable bags, and stored in a 4 °C cold room for 7 d. Lipid, protein oxidation and volatiles were determined at 1, 4, and 7 d of storage. Dietary supplementation of antioxidants significantly reduced lipid oxidation (TBARS) and protein oxidation (carbonyls) in breast rolls, and the effect of dietary antioxidants on lipid oxidation was more pronounced than protein oxidation. Chicken breast rolls from antioxidants treatment group produced significantly lower amounts of hexanal and pentanal than those from control and oxidized oil treatments (P < 0.05). However, dietary oxidized oil did not increase lipid and protein oxidation in breast rolls. Vacuum-packaging significantly delayed the onset of lipid oxidation and protein oxidation in chicken rolls during 7-day refrigerated storage (P < 0.05). Therefore, it is suggested that appropriate use of dietary supplementation of antioxidants in combination with packaging could minimize lipid oxidation in chicken breast rolls.

Purification and characterization of myosin-tripolyphosphatase from rabbit Psoas major muscle: research note

In this study, we investigated the tripolyphosphatase (TPPase) activity responsible for the hydrolysis of tripolyphosphates (TPP) in rabbit Psoas major muscle tissue. After a series of extraction and purification steps, myosin was identified to be a TPPase. Optimum pH and temperature for myosin-TPPase activity were 6.0 and 35°C, respectively. We also found that myosin-TPPase activity was significantly influenced by Mg(2+) and Ca(2+) levels, whose optimal concentrations were determined to be 3 and 6mM, respectively. Furthermore, myosin-TPPase was strongly inhibited by EDTA-4Na(+) and KIO(3), and was slightly activated by EDTA-2Na(+). These results suggest that it may be useful to regulate tripolyphosphate hydrolysis to enhance its function in meat processing.