Difference in tenderness and pH decline between water buffalo meat and beef during postmortem aging

The objective of this research was to determine the difference in tenderness and some characteristics of water buffalo meat and beef during postmortem aging. Five female crossbred water-buffalo (Philippine Carabao×Bulgarian Murrah) and five female crossbred cattle (Brahman×Philippine Native), were finished on the same diet for 6 months and slaughtered at 30 months of age. The muscle pH was measured at 40min, 3h, 7h, 24h, and 48h postmortem. Longissimus thoracis (LT) and semimembranosus (SM) muscles were excised at 2d postmortem, and shear force was measured at 2, 4, 7, and 14d postmortem. Glycogen and lactate concentrations were determined from 0, 2, and 4d LT samples, and myosin heavy chain type of buffalo and cattle LT was determined by ELISA methods. Myofibrillar protein degradation was also observed by SDS-PAGE and Western blotting of fast-type troponin T. Results showed that the buffalo meat had significantly lower shear force values compared to beef for LT and SM muscles, which was supported by a difference in troponin T degradation. Postmortem pH decline of buffalo meat was significantly slower than that of beef, which was confirmed by lactic acid concentrations, but was not explained by glycogen content. In addition, there was no significant difference in the ratio of slow to fast type muscle fibers in buffalo and cattle, indicating that myosin heavy chain type was not responsible for the difference in pH decline and tenderness between the buffalo meat and beef. This study demonstrated that the tenderness of water buffalo meat was superior to that of Brahman beef, which may have been due to the difference in pH decline and the subsequent effect on muscle protease activity.     

Comparative study of buffalo meat and beef

The aim of the experiment described in this paper was to compare buffalo and cattle breeds for meat production. Bulls and steers of both species were compared. Buffaloes and cattle were of comparable conformation on a weight to length ratio basis when slaughtered at the same liveweight. Apart from sex and weight effects, species did affect the conformation and growth of live animals, the largest differences between species being evident in the younger animals. As regards slaughter characteristics, although differences in carcass yield were slight between species, systematic differences appeared, with a higher head and skin weight for buffaloes. A higher proportion of fat was noted in the 11th rib joint of buffaloes than of cattle at the lighter weights but the difference between species lessened with slaughter weight. As far as meat quality is concerned, two major effects of species on muscle pH (24 h post slaughter) and the shear strength of raw muscle were noted. Buffaloes, which had a lower muscle pH than cattle, displayed a significantly smaller amount of collagen in the muscles studied, but the species did not differ significantly in the degree of intramuscular collagen crosslinking.     

Pressure-heat treatment of meat: A comparison of beef and buffalo meat

A pressure-heat treatment, which disrupts the myofibrillar structure of meat but leaves the connective tissues essentially intact, was used to compare the connective tissue component of toughness in the Semimembranosus and Longissimus dorsi muscles from nine Brahman cross and nine buffalo steers, 24 to 29 months of age. For assessment of samples, peak force, initial yield force and peak force minus initial yield force values were determined from Warner-Bratzler shear force-deformation curves.

In the control, non-pressure-heat treated samples, the only breed difference detected was in peak minus initial yield force value, which was significantly lower for the beef Semimembranosus muscles. However, for the pressure-heat treated samples of both muscles, peak force and peak minus initial yield force values were significantly lower for beef than for buffalo. The pressure-heat treatment could thus be used to detect differences in the contribution of connective tissue to toughness which would otherwise be obscured by the differences in the myofibrillar toughness.     

Fatty acid composition of water buffalo meat

The fatty acid composition of intramuscular lipids of Longissimus dorsi (LD), Psoas major (PM), Biceps femoris (BF), Semitendinosus (ST) muscles and liver of water buffalo male calves was determined by capillary gas-liquid chromatography. The content of total lipids in the LD muscle was found to be maximum, followed by PM, BF and ST in decreasing order (1·03, 0·99, 0·66 and 0·55g/100g of fresh muscle). Liver contained 2·65 g of total lipids per 100 g of fresh tissue. Following the anatomical location, intramuscular lipids contained 44-55% of saturated fatty acids, of which the major components were stearic and palmitic acids. Mono-unsaturated fatty acids (31-40%) composed mainly oleic acid (90%). The PUFA contents in PM, LD, ST and BF were, respectively, 11%, 12%, 13% and 16%. The predominant PUFA were linoleic (66%) and arachidonic (25%). The significance of difference of PUFA content between muscles is discussed. Liver contained 48%, 27% and 22% saturated, monosaturated and PUFA, respectively. The PUFA in liver were linoleic (36%), C20 (47%) and C22 (9%).     

Reduction in microbial load on buffalo meat by hot water dip treatment

Buffalo meat cuts from shoulder and leg portions were subjected to hot water treatment (70 and 80 °C for 30 and 60 s). Meat cuts dipped in water at ambient temperature served as control. The surface samples were analysed for microbial load, visual score for colour and numerical values of colour parameters (a(?), b(?), L(?), W). Control samples of shoulder and leg meat had a mean total plate count (TPC) of 4.15 log CFU cm(-2) and 3.81 log CFU cm(-2) and enterobacteriaceae counts of 2.33 log CFU cm(-2) and 2.26 log CFU cm(-2), respectively. Treatment of meat cuts with hot water reduced the TPC significantly (p < 0.001)with a highest reduction of 1.60 log in leg meat and 1.80 log in shoulder meat at 80 °C. Hot water treatment of meat eliminated enterobacteriaceae. Although, there was discolouration of meat by hot water treatment, the colour regained during storage of meat at refrigerated temperature (4 ±1 °C). Hot water treatment of meat resulted in loss of redness (a(?)), increase in lightness (L(?)) and whiteness (W). After storage, a(?) increased and L(?) and W decreased. The results suggested that the dip treatment with hot water reduces the initial bacterial load substantially and improves the microbiological quality of buffalo meat without causing any permanent discolouration.     

Comparison of carcase yield, carcase composition and quality characteristics of buffalo meat and beef

The yield of carcase and by-products was found to be only slightly different between buffaloes and non-improved (Busha) cattle of comparable age, feeding treatment and sex. The percentage of separable fat was slightly higher, and that of bone slightly lower, in the buffaloes. In comparing the meat from buffalo and Simmental cattle of the same age and finish, a rather higher protein content was found in the former, but this reflected a somewhat higher concentration of connective tissue in the buffalo meat. The diameter of muscle fibres in buffalo tended to be less than that of corresponding muscle in Simmental cattle (except in M. Supraspinatus of cows). These findings suggest that buffalo meat is no coarser than beef when valid comparisons are made.     

Fiber types in the longissimus muscle from water buffalo and selected domestic beef breeds

The distribution and area of longissimus muscle fiber types from two intact male water buffaloes, one Angus bull and one Charolais bull were evaluated. Only fibers of aerobic-oxidative capacity were present in the muscles of the water buffalo examined. The absence of αW fibers may imply some significant and distinct differences in muscle metabolic and functional characteristics. All three fibers types were present in the muscles from the Angus and Charolais bulls. These findings may implicate distinct and unique differences in meat characteristics from water buffalo, such as in organoleptic and/or processing traits.     

广西本地水牛与黄牛肉品质的比较

为挖掘水牛作为肉用开发潜力,选取广西本地沼泽型杂交水牛与黄牛各6头进行了肉品质的比较分析。结果表明,水牛与黄牛里脊肉和背最长肌肉的大理石花纹等级、L*、a*、b*值均无显著差异(p>0.05),但水牛里脊肉和背最长肌肉的肌肉颜色等级评分均显著高于黄牛肉(p<0.05)。水牛背最长肌肉中的干物质、蛋白质及钙含量显著低于黄牛(p<0.05)。水牛里脊肉的p H显著低于黄牛(p<0.05),但是在背长肌中却未见显著差异(p>0.05)。水牛肉与黄牛肉的熟肉率均在63%以上,但两者差异不显著(p>0.05)。水牛里脊肉中除豆蔻酸低于黄牛(p<0.05)外,其他脂肪酸均无显著差异;水牛背最长肌的豆蔻酸、棕榈酸、亚油酸显著低于黄牛(p<0.05),但其硬脂酸、油酸和亚麻酸要显著高于黄牛(p<0.05)。两者不同部位肌肉中的脂肪酸含量均以油酸含量为最高。水牛里脊肉和背最长肌肉外观颜色比黄牛肉更为暗红;水牛除背最长肌肉干物质、蛋白质、钙、豆蔻酸、棕榈酸及亚油酸含量显著低于黄牛肉,而硬脂酸、油酸和亚麻酸显著高于黄牛外,两者在其他营养指标方面没有显著差异,所测脂肪酸类别中均以油酸含量为最高。以上结果表明,长期作为役用的水牛具有与黄牛类似的肉用潜力。      

低温贮藏过程中水牛肉质构特性的变化

以广西水牛肉为原料,采用质地多面剖析法探究了低温贮藏过程中水牛肉质构特性变化规律,并进一步分析了水牛肉质构特性各指标间的相关性。结果显示:随着贮藏时间的延长,水牛肉的硬度、弹性、咀嚼性和胶着性呈不断降低的趋势,但水牛肉的内聚性呈不断增加的趋势。低温贮藏期间,水牛肉的硬度与弹性、胶着性、咀嚼性显著正相关(P0.05),但水牛肉的内聚性与各指标没有显著的相关性(P0.05)。3种低温贮藏条件下,-60℃冻藏水牛肉质构特性变化相对缓慢,其保鲜效果优于4℃冷藏和-18℃冻藏。     

Changes of meat quality characteristics and intramuscular connective tissue of beef semitendinosus muscle during postmortem aging for Chinese Yellow bulls

This study was designed to explore the changes of meat quality characteristics and intramuscular connective tissue of beef semitendinosus muscle during postmortem aging for Chinese Yellow bulls. Semitendinosus muscles were obtained at day 4 postmortem and then further aged for different periods. Chemical determinations, histological and mechanical measurements were performed for the raw and cooked steaks on days 4, 11, 14, 21, and 28 postmortem, respectively. The results showed that postmortem aging resulted in an increase in moisture content and collagen solubility, a decrease in filtering residues, primary perimysial thickness, fibre diameter, Warner‐Bratzler shear force, and transition temperature of the endomysium. The synergic effects of the myofibril and the intramuscular connective tissue determined the tenderness of aged beef.     

Sorbic acid stability in meat products of reduced water activity

This study investigated the behavior of sorbic acid in shelf-stable meats with 0.91 water activity during processing (70 °, 80 °, 90 °C) and accelerated storage (33 °, 45 °, 57 °C). In meat systems stored at 70 °, 80 ° and 90 °C, after approximately 0·5-3 days, the destruction rate of sorbic acid diminished. This change in behavior (break) was probably caused by the limited availability of oxygen and/or the inhibitory action of nonenzymatic browning products on sorbate destruction. Before the break, the rate constants were found to be related to temperature, pH, the acid used to adjust it and the humectants added to depress water activity (NaCl, glycerol, the mixture NaCl 3·5% and glycerol). After the break, none of the above mentioned effects were observed. In meat systems stored at 33 °, 45 ° and 57 °C the rate of destruction was constant with time. The rate constants of meat systems were higher than the ones obtained for aqueous systems of similar composition, revealing that meat components played an important role in the destruction of sorbates.     

Changes in phospholipids of buffalo meat during processing and storage

Effect of broiling and pressure cooking as well as alterations during refrigerated (4°C) and frozen (-10°C) storage on the phospholipids of adult male buffalo muscles viz. Triceps brachii (TB), Longissimus dorsi (LD) and Biceps femoris (BF), i.e. from three different locations were studied. Muscles differed significatly in their total lipid and phospholipid content. Cooking methods significantly altered the total phospholipid content and its fractions. Storage period did not show any significant effect on total phospholipids during refrigerated and frozen storage, whereas certain phospholipid classes viz. lysophosphatidyl choline and lysophosphatidyl ethanolamine + sphingomyelin increased significantly and major phospholipid classes viz. phosphatidyl choline and phosphatidyl ethanolamine decreased significantly. The changes in phospholipid classes were similar both in refrigerated and frozen samples but relatively more pronounced in the former. Palmitic, stearic, oleic and linoleic acids were the four predominant fatty acids in the phospholipids of buffalo meat. The effects associated with the location of muscles were evident. Differences in fatty acid composition of individual muscles in response to heat processing were observed. Heat processing significantly increased the total saturates in TB and LD muscles while it decreased in BF. The total monounsaturated and total polyunsaturated fatty acids of phospholipids decreased during refrigerated and frozen storage indicated by a significant decreass in oleic, linoleic and arachidonic acids.     

Effect of cooking and storage on lipid oxidation and development of cholesterol oxidation products in water buffalo meat

Buffalo meat was subjected to two cooking methods viz. broiling and pressure cooking and two storage procedures viz. refrigerated (4 °C) storage for six days and frozen (-10 °C) storage for 90 days. Changes in lipid oxidation and development of cholesterol oxidation products were studied in raw as well as cooked meat samples. Total lipid, phospholipid, cholesterol, free fatty acid, glycolipid and glyceride contents increased significantly on cooking of meat but did not show any significant changes during either refrigerated or frozen storage except for free fatty acid content which showed an increase. The TBA values also increased during storage but not to the extent of indicating rancidity. Cholesterol oxidation products separated by thin layer chromatography were: cholestanetriol, 7-α-hydroxycholesterol, 19-hydroxycholesterol, 7-ketocholesterol, cholesterol-α-epoxide, cholesterol-β-epoxide and an unidentified fraction. All these fractions, except for the unidentified fraction, increased on cooking and storage. The cholesterol-β-epoxide fraction was resistant to changes. Changes in broiled meat were more pronounced compared to pressure cooked meat. Frozen storage did not prevent the development of cholesterol oxidation products in buffalo meat.     

The effects of withholding feed and water on carcass shrinkage and meat quality in beef cattle

Eighty beef crossbred steers with an average weight of 493 kg (4·66 kg SD) were allocated at random to one of five treatments to assess the effects of withholding feed and water on carcass shrinkage and meat quality. The five treatments were: slaughter from the feedlot (T1); and 12, 24, 36 and 48 h periods without feed and water prior to slaughter (T2-5).Weights were taken of the live animal and the carcass to monitor shrinkage along with relevant meat quality measurements. There were no treatment differences (P > 0·05) in initial farm weight, but plant weight shrinkage increased from 31gkg(-1) for T1 to 106 g kg(-1) for T5. Warm carcass weight decreased (P < 0·05) from 278·8 kg for T1, to 270·7 kg for T3 and 261·9 kg for T5. Liver, alimentary tract components, hide and head decreased as a proportion of farm weight as time without feed and water increased. Muscle pH at 6 days post mortem was increased (P < 0·05) in T3-5 compared to T1, with the result that muscle colour became darker, and steaks had less drip loss. Shear values increased (P < 0·05) from 6·3 kg in T1 to 7·7 kg in T4 and T5 indicating an increase in muscle toughness as time without feed and water increased. It was concluded that steers lose live weight rapidly within the first 24 h without feed and water, and that these relatively short periods of time (24 h) can have detrimental effects on carcass shrinkage and muscle quality.     

Effects of postmortem storage time on color and mitochondria in beef

To assess the effects of aging time (0, 15, 30, and 45 d) and temperature (0 or 5 °C) on beef mitochondria and steak color, vacuum packaged longissimus (n = 15) and cardiac muscles were assigned to 1 of 6 temperature × time combinations. As time increased, initial red color intensity increased whereas both mitochondrial oxygen consumption and color stability decreased. The decrease in mitochondrial oxygen consumption associated with longer aging times will increase initial color intensity. However, this improvement in color development will be negated by the decreased color stability that results from the effects of storage on mitochondria.     

Effect of water activity on oxidative deterioration of freeze-dried beef

The effect of water activity on lipid oxidation in freeze-dried beef was studied. Analytical indices of the extent of oxidation (thiobarbituric acid (TBA) number and Ex 350Ee320 fluorescence ratio) showed that samples of water activity 0.270 underwent less oxidation during 84 days storage in oxygen at 50°C than samples of lower water activity. Samples stored under nitrogen, irrespective of water activity, did not show any oxidation.     

Casein peptides with inhibitory activity on lipid oxidation in beef homogenates and mechanically deboned poultry meat

Bioactive peptides obtained by enzymatic hydrolysis of casein may have antioxidant activity. In this work, casein peptides were obtained using the proteolytic enzymes Alcalase and Flavourzyme. Casein was hydrolyzed for 4 h at 50 °C and pH 8, and the resulting peptides were analyzed. The enzymatic hydrolysis with Flavourzyme resulted in higher concentration of soluble protein and free amino acids, and produced peptides with lower molecular mass than those obtained with Alcalase, as observed by gel permeation chromatography and polyacrylamide gel electrophoresis. Casein peptides obtained with Flavourzyme also exhibited greater antioxidant capacity using the ABTS radical method. Casein peptides (20 mg ml⁻¹) effectively inhibited lipid peroxidation in ground beef homogenates and mechanically deboned poultry meat. Casein peptides may be useful in meat processing as another naturally occurring antioxidant, helping to prevent off-flavor formation in meat products and increasing shelf life.