ABSTRACT The objective of this study was to determine the influence of hydrodynamic pressure processing (HDP) and aging on the overall quality and protein characteristics of pork loins. Boneless pork loins (n = 12) were split into anterior and posterior halves and were assigned to control and HDP treatments. Following treatment on day 0, each half was divided into two portions (0 and 7 days aging). Samples were removed for the determination of Warner–Bratzler shear force (WBSF), centrifugal moisture loss (CML), gravitational drip loss (DL), color, protein solubility and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) analysis of whole muscle protein extracts. WBSF decreased with HDP (P < 0.05) and aging treatments (P < 0.0001). CML decreased (P < 0.0001) with aging. Controls exhibited slightly less DL after 1 day than HDP samples, but the increase in DL between 1 and 7 days was similar for control and HDP samples. Treatment effects on L*, a* and b* measurements were minimal. Myofibrillar and total protein solubility were higher (P < 0.01) in HDP samples compared with controls at day 0 but not at day 7. Sarcoplasmic protein solubility decreased (P < 0.05) with aging. SDS‐PAGE analysis of muscle proteins demonstrated a strong aging effect and only minor HDP differences. With aging, bands corresponding to 30–33 and 135 kDa increased (P < 0.0001), while bands corresponding to 38 and 95 kDa decreased (P < 0.05) in intensity (relative to the actin band). The 60 kDa band intensity increased (P < 0.05) with both aging and HDP treatments. Thus, data from this study suggest that HDP enhances aging tenderization in pork loins through the physical disruption of the muscle ultrastructure while having little detrimental effect on other parameters of pork quality.PRACTICAL APPLICATIONSThis study demonstrates that hydrodynamic pressure processing is an effective postharvest technology for enhancing aging tenderization in pork loins through the physical disruption of the muscle ultrastructure with minimal impacts on other pork quality parameters such as water‐holding capacity and color.
ABSTRACT The study was aimed at optimizing the post package reheating (pasteurization) hurdle for processing shelf stable pork sausages. The temperatures evaluated were 80, 90 and 100C. Reheating resulted in an increase in pH, which was slight at 80C while significant (P < 0.05) at 90 and 100C. Moisture and fat contents decreased significantly while protein content increased significantly with increase in reheating temperature. Reheating of the sausages up to 90C significantly improved their hardness and shear force values. Reheating to 90 and 100C increased the redness (a‐values) and decreased yellowness (b‐values) of the sausages. Despite a lower initial value, the pH of the control sausages increased by 0.3 units on day 3 of storage, while that of reheated samples showed only a slight increase (0.04–0.05 units). About 10 times increase (0.05–0.50) in thiobarbituric acid reacting substances values observed for control sausages during 3 days storage at ambient temperature (37 ± 1C) while the increase in reheated samples was significantly (P < 0.01) lower. Total plate counts reached about 7 log cfu/g on day 3 of storage in control sausages, but it took about 9 days and 12 days, respectively, for those reheated to 80 and 90C and 100C. Post package reheating of pork sausages resulted in initial reduction in most of the sensory attributes, but helped to maintain these attributes for longer time during storage at 37 ± 1C and the sausages subjected to 90C maintained higher overall acceptability compared to other treatments throughout the storage period of 12 days.PRACTICAL APPLICATIONSDevelopment of a meat product that could be stored at ambient temperature will save the expenses on refrigeration energy and cooler space requirement which is of importance in developing countries, where electricity is a major problem. Further, the successfully evolved process can be tried for developing different shelf stable meat products with other meats.
ABSTRACT This study was conducted to determine the effects of dietary glycine betaine on pork quality and blood characteristics. A total of 80 female pigs (Landrace × Yorkshire × Duroc) were randomly allotted into one of four experimental diet groups. Each group of pigs fed with a commercial diet (control) added with 0.2 g glycine betaine (T1), 0.4 g glycine betaine (T2) and 0.6 g glycine betaine (T3)/kg diet during 40 days. Glycine betaine concentrations in plasma and loin muscle were significantly increased by dietary glycine betaine; however, triglyceride concentration in serum was decreased by dietary glycine betaine. Creatine phosphokinase concentrations in plasma had no significant difference among the dietary groups. Redness (a*) was significantly higher in T2 and T3; however, at the first and seventh days of storage, redness (a*) was not significantly different between dietary groups. Shear force was significantly higher in dietary glycine betaine groups at the first day of storage. Cholesterol content was significantly lower in T2 and T3, whereas T1 was not significantly different compared with the control group. In fatty acid composition, the ratio of saturated fatty acids was increased, whereas unsaturated fatty acids were decreased by dietary glycine betaine.PRACTICAL APPLICATIONSGlycine betaine is an amino acid (trimethylglycine) present in most organisms, and is an obligatory intermediate in the catabolism of choline. Glycine betaine has been reported to affect some aspects of pork qualities. As a result of this study, dietary glycine betaine should improve meat redness and reduce cholesterol. However, dietary glycine betaine did not influence creatine phosphokinase levels in plasma. These results will be helpful to the pork industry and meat scientists for improving meat qaulity.
ABSTRACT The aim of this study was to compare chemical parameters, fatty acid composition and mineral contents of farm animal meats which are marketed in Turkey. Different kinds of meats were purchased from the meat market including beef, lamb, broiler, turkey, ostrich and quail meat, which are mostly preferred for different reasons by consumers. However, little information exists about the composition of meats of different farm animal species. The results of proximate analysis showed that the high level of protein (24.38%) and low level crude fat (1.19 ± 0.13%) were found in turkey meats, while the low level of protein (18.75%) and high level fat (8.79%) were found in lamb meats. The fatty acid compositions of meats were in the range of 22.68–48.37% for saturated, 21.38–42.45% for monounsaturated and 3.75–47.47% for polyunsaturated acids. The highest micro mineral was determined as zinc (5.7417 ppm) in lamb and ostrich (5.0923 ppm). PRACTICAL APPLICATIONS Consumers attitudes toward meat “safety” greatly affect their overall choices and the variety of meat types available for sale. Some meats are more likely to cause heart disease – saturated fats and trans fats. These fats are usually found in foods from animals such as meat milk, cheese and butter. The dietary saturated fatty acids elevate serum cholesterol concentrations, whereas polyunsaturated fatty acids reduce serum cholesterol concentrations and monounsaturated fatty acids have little or no effect. Therefore, knowledge concerning the exact fatty acid composition of the meat is extremely important for the consumer and processing sector. This study provides comparative information to consumer and processing sector about proximate and fatty acid compositions and mineral contents of beef, lamb, broiler, turkey, ostrich and quail meats.
ABSTRACT The effect of the cooking temperatures (65, 70, 75, 80 and 85C) and the cooking time (15, 20, 25, 30 and 35 min) on color and gel strength of surimi‐like pork (SLP) derived from porcine semi‐membranosus muscle was investigated. The hardness value of SLP gel increased significantly with increasing cooking temperature. However, after 20 min cooking time at 75C, the gels did not significantly increase in hardness. Results implied that cooking time and temperature both had effects on color and gel strength of SLP. PRACTICAL APPLICATIONS This study was conducted to investigate the effect of cooking temperature and cooking time on color and gel strength of surimi‐like pork. Cooking temperature and times are very important to manufacture of the surimi‐like pork.
ABSTRACT The aim of this study was the determination of the effect of sodium metabisulfite and citric acid on the quality of crayfish. The first group of crayfish (control) was boiled, chilled and packaged. The second group was treated with chemicals (100 g live crayfish for 1 L water, 0.1 g sodium metabisulfite and 0.5 g citric acid), then boiled, chilled and packaged. The last group was boiled with the same chemicals, chilled and packaged. Samples were stored at + 4C. Treated samples were acceptable until the eighth day. However, the control samples spoiled according to the sensory analysis on the sixth day, and their pH, mesophilic and psychrophilic aerobic bacteria counts were ( P < 0.05) higher than treated ones on that day. Using citric acid and sodium metabisulfite lower than the limits (50 mg/kg for cooked crustaceans according to Turkish and European Union legislations) improve the sensory quality and generally decrease the pH, mesophilic and psychrophilic aerobic bacteria counts of crayfish. PRACTICAL APPLICATIONS The results obtained from this study demonstrated that sodium metabisulfite and citric acid, used in limits determined by law, especially improve the sensory quality of crayfish. To maintain more remarkable results, using other chemicals with or without sodium metabisulfite and citric acid according to the legislations may be studied. These findings can be well utilized by researchers as well as manufacturers in their studies on improving the shelf life of crayfish. Based on our results, suitable methods of processing can be developed for improving the shelf life of crayfish.
ABSTRACT The oxidation of myofibrillar and sarcoplasmic proteins of thin‐lipped mullet (Liza ramada) in different ages during refrigerated storage (4C), and in vitro oxidation of muscle after 2 and 24 h incubation with Fe+2/H2O2 at 4C were evaluated by means of protein carbonyl content. Changes in myofibrillar and sarcoplasmic proteins were estimated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The carbonyl content of myofibrillar proteins exhibited a regular increase at 2 years of age during the refrigerated storage for 10 days (P < 0.05), and increased at 4 and 6 years of age after 5 days of cold storage (P > 0.05), and then did not significantly change between 5 and 10 days of storage (P > 0.05). Sarcoplasmic proteins showed a decrease in the carbonyl content at 2 years of age during 10 days of storage. However, no significant changes were observed in carbonyl content of sarcoplasmic proteins at 4 and 6 years of age (P > 0.05). An increase in carbonyl content of whole muscle, but not statistically significant, was found at 2, 4 and 6 years of age during 10 days of cold storage. There were no significant differences in oxidation of thin‐lipped gray mullet proteins in all ages between 2 and 24 h of incubation with Fenton‐like oxidation system (Fe+2SO4/H2O2) at 4C (P < 0.05). However, there was a tendency to find an increase in carbonyl content in all ages after 24 h of incubation. Electrophoretic studies in the presence and absence of β‐mercaptoethanol showed that high‐molecular weight polymers via disulfide cross‐linking and/or degradation/digestion by proteolysis could be formed in the myofibrillar proteins in different ages. Slight changes were observed in sarcoplasmic proteins of thin‐lipped gray mullet both in the absence and presence of a disulfide‐splitting agent. These results suggest that there is a probable link between protein oxidation and protelytic degradation of myofibrillar proteins during postmortem storage, and the effects of cold storage on oxidation and possible changes in myofibrillar and sarcoplasmic proteins could be changed depending on ages in same species.PRACTICAL APPLICATIONSThe degradation of muscle proteins caused by proteolysis is one of the most important quality attributes of fish muscle throughout cold storage. However, knowledge about the effect of oxidative process on proteins and their effect on postmortem quality of fish is less known. In this study, we found a probable link between protein oxidation and degradation of thin‐lipped mullet myofibrillar proteins, and their proteolysis may be stimulated by oxygen radicals during postmortem storage. These determinations are important to prevent protein degradation and improve the shelf life of thin‐lipped mullet during postmortem storage.
ABSTRACT A confounded factorial conjoint choice experiment was conducted with 12 University of Nebraska classes (six Animal Science and six Statistics classes) to examine the effects of price, country‐of‐origin labeling, marbling, tenderness guarantee, traceable‐to‐the‐farm labeling, class discipline and the possibility of receiving a gift on preferences toward beef rib‐eye steaks. All factors, except class discipline and the possibility of receiving a gift, had a significant impact on consumer preferences. Based on the odds ratios, the relative importance of these factors were price (1.97), tenderness guarantee (1.92), country‐of‐origin label (1.68), marbling (1.43) and traceable‐to‐the‐farm labeling (1.30). This relative order of importance was also supported by the willingness‐to‐pay estimates: tenderness guarantee ($3.03/lb), country‐of‐origin label ($2.40/lb), marbling ($1.67/lb) and traceable‐to‐the‐farm label ($1.20/lb). Preferences were also affected by a number of interactions. Our results indicated that a tenderness guarantee and country‐of‐origin label are almost as important as price in student purchase intent, but that the relative importance was dependent upon other factors such as the level of knowledge about beef and marbling level. In addition, the large number of significant interactions indicated and the ability to evaluate these interactions with confounded factorial conjoint experiments demonstrated the importance of using these experimental designs. PRACTICAL APPLICATIONSThe relative importance of the factors studied was price, tenderness guarantee, country‐of‐origin label, marbling and traceable‐to‐the‐farm labeling. Interactions among the factors also suggested that consumers knowledgeable about beef placed a high value on marbling when the country‐of‐origin was known, while the country‐of‐origin label had little impact on the value of marbling for less knowledgeable consumers. These results are useful in the packaging, placement, marketing and advertising of beef steaks. Also, we used confounded factorial conjoint choice experiments, which are promising new designs useful for assessing the effects of many factors and their interactions on consumer preferences that do not overburden respondents with long survey forms and provide more information than traditional choice experimental plans.
ABSTRACT In an attempt to improve the chemical, physical and sensory properties of beef burgers containing 11.5–13.7% fat, trials were carried out on eight experimental burger formulations containing carrageenan (0.5%), texturized soya (1.5%) and trisodium phosphate (0.5%), either alone or in different combinations, and compared with a control prepared only with the addition of salt and water. The data obtained were analyzed using a complete randomized design to study the effect of treatments on the proximate composition, thiobarbituric acid reactive substances (TBARS) value, percentage cooking loss, percentage diameter loss and sensory evaluation. The significant difference of the mean was determined using the least significant difference method. Although initial weight, cooked weight, initial diameter length and cooked diameter length were analyzed using means ± standard error. Analyses revealed unexpected interactions between some of the ingredients, the nature of which was not investigated. Results showed that the addition of carrageenan alone improved crude protein content, juiciness and overall acceptability of the beef burger, but it affected the appearance negatively, although there was no significant effect on diameter loss and thickness loss when compared with the control. Beef burger prepared with the addition of texturized soya alone increased moisture binding and protein level, while it lowered flavor score compared with the control. With respect to the oxidative rancidity, TBARS value was found higher for the market sample; this value was significantly lower with the addition of combination of texturized soya and trisodium phosphate. It has been found that the addition of a combination of carrageenan, texturized soya and trisodium phosphate reduced the cooking loss compared with the control, while there was no significant effect on the diameter loss and thickness loss of all treatments. It was also found that the combination of carrageenan, texturized soya and trisodium phosphate improved all sensory attributes and improved protein contents compared with the control. The sensory scores were highly correlated with each other. No significant correlations were found between moisture percentage and cooking loss together and sensory attributes, while there were high correlations between the TBARS and fat percentage with sensory attributes. PRACTICAL APPLICATIONSReducing the fat content of beef burgers can make a significant contribution to human health and ensure the continuing popularity of this type of convenience food around the world. However, merely using leaner meat does not provide a product with the necessary quality attributes. So, practically, it has been found that the addition of carrageenan, texturized soya and trisodium phosphate can improve the beef burger sensory properties as a whole, including the appearance, color, flavor, tenderness, juiciness and overall acceptability. In addition, the oxidative rancidity (thiobarbituric acid reactive substances) of the product can also, be reduced. Above all, the quality of fat and its level has high correlation with the rancidity value and burger sensory attributes. Therefore, information is needed on suitable ingredient combinations that can maintain or enhance the quality of a low‐fat version of the beef burger.
ABSTRACT Lactic acid salts with three different cations (K, Na, Ca) were investigated at three lactate (L) concentrations (0.1, 0.3 and 0.6 M) to evaluate in vitro metmyoglobin‐reducing activity (MRA) at three pH levels (5.7, 6.4 and 7.4). All lactates generated MRA at normal meat pH (5.7), with greater MRA at pH 7.4 than at both pH 6.4 and 5.7 (P < 0.05). No consistent differences were noted among lactates for generating MRA, except at pH 7.4 where CaL was greatest (P < 0.05). At pH 6.4 and 7.4, MRA increased (P < 0.05) as lactate concentration increased. This study provides evidence that lactate oxidation at postmortem muscle pH generates reducing equivalents and that addition of CaL, NaL or KL should increase MRA and color stability.PRACTICAL APPLICATIONSLactate products are commonly used by the meat industry for microbial control, specifically of Listeria monocytogenes. Previous research has shown lactates to increase meat color stability as well. This research examines whether lactate products, with three different cations, can generate metmyoglobin‐reducing activity (MRA) to a similar extent. Results of this study indicate that the three lactates increase MRA in vitro, even at postmortem meat pH (5.7). These data should lead to further testing of lactate products in both fresh and processed meat systems in different packaging formats, which would add additional information to meat processors' decision‐making process.
ABSTRACT The effect of onion (Allium cepa L.) extract on the fresh beef fillet meat was investigated. Beef fillet samples were cut into pieces and treated with 5, 10, 20 and 50 % onion‐water extract (v/v) and stored in refrigeration conditions at 4C. Microbiological quality of the samples was investigated during storage for (0, 1, 3, 6 and 9) 9 days. Increasing concentrations of onion extract significantly affected Escherichia coli and yeast‐mould counts (P < 0.05, P < 0.01); Pseudomonas spp., aerobic mesophilic bacteria and total coliforms were not affected significantly (P > 0.05) for some concentrations and days. The count of bacteria of the samples reached and exceeded the spoilage limit after 9 days at 4C. High concentrations of onion extract were effective in protecting beef meat, depending on the reduction of some microbial contaminations.PRACTICAL APPLICATIONSThe effects of onion extracts on beef meat microbial spoilage were evaluated. Microbial spoilage of meat is an important factor influencing consumer health directly as well as influencing the cost and food availability. Antimicrobial activity of onion juice in different researches was previously reported. In this study, onion extract reduces some microbial contamination of beef fillet meat by inhibiting Escherichia coli and yeast‐mould counts during 9 days at refrigeration conditions. Onion extract can find applications especially with service preservation of meat meals, with the aid of refrigeration, which is also prepared with onion flavor (döner kebap, meat balls, cig köfte, etc.).
ABSTRACTAdministration of antibiotics or hormones to broiler chickens for therapeutic and performance‐enhancing purposes may lead to deposit of residuals in their carcasses. This could be a potential human health hazard upon exposure to these residues. The objective of this study was to detect residue levels of tetracycline, streptomycin, sulfamethazine, chloramphenicol, trenbolon, estradiol‐17ß, and testosterone in broiler chicken meat commonly marketed in the Sultanate of Oman. The Enzyme‐Linked Immunosorbent Assay technique was used to detect residues in 128 broiler chicken breast muscles, representing various poultry processing companies from six countries representing four continents. Generally, samples contained various levels of residues of different antibiotic and hormones. Tetracycline levels ranged between 35 and 56 ng/kg (mean 45.9); streptomycin ranged between 30 and 155 ng/kg (mean 100.0); sulfamethazine levels ranged between 0.079 and 5.60 ng/kg (mean 1.07); trenbolon ranged between 0.70 and 3.12 ng/kg (mean 1.67); estradiol 17‐ß ranged from 0.06 to 2.00 ng/kg (mean 0.70); chloramphenicol ranged from 5.00 to 74.00 ng/kg (mean 14.38); and testosterone ranged from 4 to 70 ng/kg (mean 25.53). There were significant differences in residue levels of antibiotics and hormones between the companies and countries. There were significant differences in antibiotic and anabolic agents' residues with the exception of trenbolon between continents. This study indicated that broiler chicken meat products available in the local market contained various levels of residues of several antibiotic and anabolic agents. Although levels of some of these residues did not exceed the maximum allowable limits, they still poise a human health hazard.PRACTICAL APPLICATIONSThere has been an increasing awareness of the widespread drug therapy and the possibility of residues in meat and consequently the potential human health hazards associated with exposure to these residues. Many of these are now classified as carcinogenic, toxic and allergenic, which interfere with human natural physiological functions. The Enzyme‐linked Immunosorbent Assay (ELISA) is one of the sophisticate techniques to detect residuals based on enzyme‐labeled reagents. Therefore, investigations using ELISA technique to monitor residues of various drugs in meat products should be applicable to insure the safety of animal food products for human consumption.
ABSTRACT The seasonal lipid variation and fatty acids compositions were assessed in white and red muscles, head, viscera, liver and gonads of little tuna Euthynnus alletteratus. Lipid contents showed a significant variation (P < 0.05) throughout the year, the maximum level was found in the liver during winter season (27.28 g/100 g). The lowest fat contents were found in gonads during the winter and spring seasons, with levels of 1.56 and 1.49 g/100 g, respectively. White and red muscle fat levels increased significantly from winter to summer; viscera lipids, however, showed a significant decrease during the same period. Generally, the increase of the polyunsaturated fatty acids percentage in most organs was usually accompanied with a decrease of saturated fatty acids. It was shown that lipid content was higher in the head and liver compared to other compartments, and the fatty acid composition in the different organs of little tuna was significantly influenced by spawning and season. All lipids extracted contained significant amounts of docosahexaenoic acid and eicosapentaeneoic acid, which have various physiological functions.PRACTICAL APPLICATIONSMost of the available literature showed little information about biochemical composition of fillets and by‐products of some fish species and are, therefore, not complete for industrial purposes as application in food or feed nutriment. The practical application of this study was performed by the determination of fatty acids levels of little tuna fillets (white and red muscles) and by‐products (head, viscera, liver and gonads) to further explain the evolution of lipid and fatty acids throughout the year. Finally, this manuscript may provide some valuable information for other scientists working in the field of food technology.
ABSTRACT The primary goal of this study was to determine the residual nitrite‐reducing effects of glucono‐δ‐lactone (GDL) and ascorbic acid (AA) in Turkish‐type fermented sausage. Response surface methodology was used to investigate the simultaneous effects of processing variables, e.g., nitrite (0–200 mg/kg sausage), GDL (0–0.5% w/w) and AA (0–500 mg/kg sausage) on pH, moisture, residual nitrite, proteolysis, lipolysis, peroxide, yield and sensory score of the sausage. AA significantly ( P < 0.01) decreased the residual nitrite level; however, quadratic effect of AA showed an inverse effect. GDL did not produce the same effect on the residual nitrite level. The processing variables had no prominent effect on the proteolysis, lipolysis and peroxide. GDL and AA addition showed a negative effect on the yield and sensory scores of the sausages. The regression model predicted the optimum residual nitrite content to be 0.75 mg/kg. The critical values for nitrite, GDL and AA to obtain this optimum level were 147.56 mg/kg, 0.17% and 565 mg/kg, respectively. PRACTICAL APPLICATIONS Residual nitrite level is a major problem in the Turkish‐type fermented sausage product with respect to some health concerns, residual nitrite causes a possible formation of the carcinogenic N ‐nitrosamines. The results of this study can be applied to reduce the residual nitrite level in sausage and to find the optimum levels of nitrite, glucono‐δ‐lactone and ascorbic acid levels to maintain the characteristic sausage quality properties. Based on the results, ascorbic acid can be used to reduce the residual nitrite levels in the sausage.
ABSTRACT The objective of this study was to determine the effects of pre‐harvest Mg supplementation and stunning method on longissimus (LM) and semitendinosus (SM) pork muscle quality. Magnesium was supplemented for 2 days in drinking water (300 ppm) before pigs were harvested at a commercial packing plant using either electrical or CO 2 stunning. Magnesium supplementation did not affect ( P > 0.10) ultimate pH, initial fluid loss, retail display purge loss or color of the LM and SM. Pork quality was generally improved in LM and SM samples obtained from the plant using CO 2 stunning as evidenced by reduced initial fluid loss ( P < 0.001), reduced purge loss ( P < 0.05) and lower L * (darker), a * (less red) and b * (less yellow) values ( P < 0.05) during an 8‐day retail display. Pork quality was improved when using CO 2 stunning technology; however, Mg supplementation did not improve pork quality in either plant. PRACTICAL APPLICATIONS Pork quality is one of the main issues for the pork industry to consider in order to remain competitive in a global market. We evaluated the supplementation of Mg through the water in collaboration with a swine production company and two large commercial packing plants. Clear differences in pork quality were evident, with the packing plant using CO 2 stunning having superior pork quality compared with the plant using electrical stunning. Supplementation of Mg through water can be applied on the farm immediately at a very low cost, but was not effective in improving pork quality in two commercial packing plants under practical conditions.
ABSTRACT The objective of this study was to determine the relationship between pH and fresh pork quality. Pigs ( n = 988) were harvested at one plant on 6 days over a 2‐month period. Loin pH was recorded at 45 min, and 3 and 24 h postmortem. Loins ( n = 840) were classified based on ultimate pH into four categories: low ( ≤ 5.44), low/normal (5.45–5.74), high/normal (5.75–6.04) and high ( ≥ 6.05). A majority of loins (53.3%) were classified as low/normal, while only 1.3% were classified as low. It was confirmed that 24 h pH was the best predictor of key meat quality traits because 45 min and 3 h pH accounted for less than 5% of the total variation in quality traits. The pH at 24 h postmortem is the best predictor of quality of the three time points tested in this population, because it accounted for over 10% of the variation in several quality attributes. PRACTICAL APPLICATIONS Ultimate pH is becoming more widely used in industry applications to segregate carcasses prior to fabrication. The pH has been linked to several important attributes of pork quality, including water‐holding capacity, tenderness and color. While it has been suggested that the pH measured at earlier time points postmortem can be used to predict pork quality, the results of this study suggest that the pH at 24 h postmortem is the best predictor of these characteristics. The addition of 45 min or 3 h pH is of little predictive value for meat quality characteristics in this population. While 24 h pH accounts for some variability in pork quality attributes, more work is still needed to determine factors impacting the quality of pork.
ABSTRACT The purpose of this study was to determine the effect of electrolyte‐glucose solution (EG) while in lairage on carcass and meat quality of young bulls. Twenty Holstein Friesian young bulls were allocated to two groups, a control group (group C, n = 10) and an electrolyte‐glucose therapy group (group EG, n = 10). Muscle glycogen content was significantly higher in EG (11.6 mmol/L) compared with C (8.8 mmol/l). Cooler shrinkage, muscle pH 24 h postmortem were lower in EG than in C; however, differences were found insignificant. Steaks in EG preserved color vividness along the blooming time, and had less thawing loss. Shear force of EG were significantly lower those of C (P < 0.05) and consumer sensory evaluations indicated that EG steaks were preferred to C steaks (P < 0.001). It was concluded that EG therapy for 18 h in lairage improved carcass and meat quality.PRACTICAL APPLICATIONSIn this study, the efficacy of liquid post‐transit antemortem electrolyte‐glucose therapy on carcass and meat quality of young bulls held in lairage was examined. Our results confirmed previous research results that have shown prevention from muscle glycogen loss in cattle before slaughter improved pH and meat texture. It was concluded that attributes (odor, flavor, tenderness and overall acceptability) at all aging periods (24 h, 4, 7 and 14 days) the electrolyte glucose treatment (EG) was significantly superior to the control. The study clearly showed that preslaughter EG treatment can be effective in improving carcass and meat quality.
ABSTRACT The postmortem factors like rate of glycolysis and muscle shortening have a major role on meat characteristics and these have been efficiently manipulated by methods like chilling regime, electrical stimulation and different hanging. These methods have been optimized with time leaving a little scope for further improvement. During the harvesting process of meat there is a generalized cell death often referred to as necrosis or apoptosis. This process of cell death has been well studied with respect to various physiological functions in vivo but its role in postmortem meat quality has received little attention. It is mainly regulated by caspases and also probably by calpains, cathepsins, proteasomes, lysosomal enzymes and other molecules, antioxidants and stress proteins. The term apoptosis appears to be more appropriate as evident by involvement of the enzyme systems and cell shrinkage. Further, examination of postmortem events effecting meat quality and correlate them to understand the cell death process may reveal the possible involvement of both apoptosis and necrosis processes, one preceding the other. This article is an attempt to review the apoptotic process of various cell lines and possible implication for muscle cells after slaughter and meat quality control.PRACTICAL APPLICATIONSUnderstanding the intricate biochemical mechanisms governing cell death processes after slaughter may help us provide better solutions for preslaughter animal handling and postslaughter interventions to manage meat toughness. Investigations on these tracks would distinguish muscle cell death processes after slaughter from apoptosis or necrosis, and consequently may lead to enhanced technological meat quality as available literature suggests that a number of molecules such as caspase family are likely to be involved in cell death process after slaughter and also in meat tenderization.
ABSTRACT This work evaluates the chemical, microbiological and sensorial characteristics of vacuum‐packed sea bass processed by different cooking methods under different time/temperature conditions and storage at 2C. The heat treatments applied in core were: 5 min, at 180C for frying, 30 mi, at 230C for baking, and 16 min at 2450 MHz for microwave cooking. Chemical, microbiological and sensory quality changes were investigated periodically. In all groups; the total viable and psycrophilic bacteria counts increased throughout the storage period of vacuum‐packed sea bass. Total viable counts of fried, baked and microwave‐cooked sea bass reached 6.06, 7.00, 7.24 log cfu/g, respectively, after 15 days. On day 15, the total volatile base nitrogen (TVB‐N) value of microwave‐cooked sea bass exceeded the allowable limit of 38.72 mg/100 g, whereas the TVB‐N value of fried and baked sea bass reached 22.46 and 29.85 mg/100 g, respectively. Therefore, it can be concluded that frying at 180C for 5 min in core is the most effective cooking method to ensure the safety and extend the shelf life of fried sea bass, preserving its microbiological guality. PRACTICAL APPLICATION This study establishes the chemical, microbiological and sensory quality of vacuum‐packed sea bass and emphasizes the relevance of the quality changes of the different cooked sea bass. Heat treatments and storage temperatures are very important to ensure the safety of the fish product.
ABSTRACT The effects of starter culture and processing on the microbiological and biochemical characteristics of turkey sucuk were studied during production and storage. No differences (P > 0.05) in proximate composition and salt contents were found in sucuks produced either by traditional or heated methodologies. Both traditional (P < 0.05) and heat‐processed (P > 0.05) sucuks that incorporated S1 had the lowest pH value, and thus the highest titratable acidity. Heating process resulted in about 1 log unit reduction in yeast counts and 1.5 log unit reduction in lactic acid bacteria, total mesophilic aerobic bacteria and micrococci–staphylococci counts of all sucuks. Within the heat‐processed sucuks, heating stage did not result in a significant change in nonprotein nitrogen contents (P > 0.05). Changes in myofibrillar and sarcoplasmic protein were observed because of proteolytic changes during ripening, but, in general, no major difference was observed between sodium dodecyl sulfate‐polyacrylamide gel electrophoresis patterns as a result of starter culture treatments.PRACTICAL APPLICATIONSResults of this study can be applied to improve some biochemical and microbiological characteristics of fermented turkey sausages. The findings showed that utilizing commercial starter culture mix, containing Lactobacillus sake, Staphylococcus carnosus and Staphylococcus xylosus II resulted in lower pH value with a higher titratable acidity than traditional style‐fermented turkey sausages. These parameters are responsible for texture development and characteristic taste of fermented sausages.
