Physical Characteristics of Pectoralis superficialis from Broiler Carcasses Chilled in Either Water or Sodium Chloride Solutions Under Commercial Conditions

Broiler carcasses were chilled in water only (control) or brine (NaCl) solutions for 45 min using a three step temperature reduction [21°C (prechill), 13°C, and 1°C] in all possible combinations of 2.5, 5.0, and 7.5% NaCl. Water or brine retention following chilling between any brine treatment and the control did not differ significantly (P < 0.05); however, control carcasses had greater driploss. Cooked meat from controls had higher shear force values, lower percent moisture, and lower NaCl concentration than meat from brine treatments. This indicated that all brine treatments tenderized broiler meat. As chill solution temperature was decreased, a more tender product resulted from increased NaCl concentration in the chill solution.     

THE SHEAR FORCE OF VERY-RAPIDLY CHILLED LAMB 1: THE EFFECT OF CARCASS SPLITTING

The effect on tenderness of splitting lamb carcasses longitudinally under very-rapid chilling conditions was investigated. Whole (unsplit) and split carcasses were chilled in very-rapid chilling conditions (−20C for 3.5 h followed by chilling at 4C for 20.5 h) and conventional chilling conditions (4C for 24 h), giving a total of four treatments. Loin (M. longissimus thoracis et lumborum) shear force was measured at f and S days postmortem by Warner-Bratiler shear force measurement. By 5 days postmortem, split carcasses were not different (P>0.05) in shear force to unsplit carcasses when conventionally chilled but differences (P<0.05) were present between unsplit and split carcasses when very-rapidly chilled (57.7 N vs 41.5 N, respectively).     

Impact of carcass scalding and chilling on muscle proteins and meat quality of broiler breast fillets

The objective of this study was to determine the effects of broiler carcass scalding and chilling methods on meat quality and muscle proteins. During processing, carcasses were hard (60 °C, 1.5 min) or soft (52.8 °C, 3 min) scalded, and either immersion chilled (IC: 0.5 °C, 40 min) or air chilled (AC: 0.5 °C, 120 min). Breast fillets were deboned at 4 h postmortem and used for measuring meat quality and muscle protein characteristics. Scalding by chilling treatment interaction effects on meat quality were not observed. Air chilled carcasses had greater pH₂₄, and reduced drip loss and shear force compared to IC carcasses. Cook yield, color (L*a*b*), and moisture content were not different between chilling treatments. Scalding treatments did not influence quality traits. Sarcoplasmic protein solubility was not influenced by chilling treatment, but was greater in hard versus soft scalded carcasses. Myofibrillar protein solubility was greater in fillets from soft scalded IC carcasses. Alterations in the electrophoretic profiles of the myofibrillar and sarcoplasmic proteins due to treatments indicated minor changes in protein degradation and solubility. Data suggest that while only chilling method influenced meat quality, both scalding and chilling methods influenced protein solubility and degradation in breast fillets deboned 4 h postmortem.     

Effect of chilling applied to suckling lamb carcasses on hygienic, physicochemical and sensory meat quality

The effect of post mortem temperature treatment on suckling lamb carcass and meat quality was study. Conventional (2°C for 24h), ultra-rapid (-20°C for 3.5h, 2°C until 24h) and slow chillings (12°C for 7h, 2°C until 24h) were compared. Total viable counts (TVC), weight losses, and pH and temperature falls were recorded on carcasses. Meat colour, water holding capacity (WHC), Warner-Bratzler shear force, sarcomere length and sensory analysis were evaluated in M. longissimus. Ultra-rapid treatment reduced TVC and weight losses. The pH decline was faster in slow chilled carcasses than in faster chilled carcasses. No significant differences were found for colour and WHC. Slow treatment carcasses showed significantly lower shear force and higher sarcomere length. In the sensory analysis, tasters also rated the early post mortem slow-treated meat as more tender, less fibrous and chewy. Therefore, delay chilling in suckling lamb carcasses made it possible to obtain meat with better organoleptic characteristics, without affecting weight loss or hygienic quality.     

Vascular perfusion chilling of red meat carcasses – A feasibility study

Meat carcasses must be chilled to below 7 °C before leaving the slaughterhouse. Typically this is done by passing cold air over the surfaces of eviscerated and de-hided carcasses. This surface cooling can take many hours to reduce centre temperatures to below 7 °C. In vascular perfusion chilling (VPC), a cold fluid is circulated through the intact vascular system, offering significant reductions in cooling time.This paper describes a small feasibility study to evaluate vascular perfusion techniques for rapid chilling of lamb carcasses using a proprietary Flo-ice^™ system. This produces pumpable ice slurries containing very fine ice particles, suitable for circulating through vascular systems.VPC was found to be capable of rapid initial reduction of carcass temperatures in comparison with air chilling (mean times to 20 °C in deep legs were reduced from 2.6 to 1.3 h, which was significantly different at P < 0.05). In all cases however, uptake of perfusate into the carcasses occurred. This limited the duration of the perfusion treatment and as a result restricted the period of enhanced cooling. Samples from carcasses treated with VPC were lighter (P < 0.05, with mean measured L value increasing from 43.4 to 46.8) and more yellow (P < 0.05, with mean measured b value increasing from 6.7 to 7.9) than samples from conventionally chilled carcasses, and had lower shear force values when cooked (P < 0.05, with mean force reducing from 10.0 to 6.8 kg). This was most probably due to the added water in the meat. Microbial quality of the meat was not significantly affected by the perfusion treatments.     

Sodium chloride as a preferred protein extractant for pork lean meat

The protein extractability of sodium chloride (NaCl), potassium chloride (KCl) and lithium chloride (LiCl) under a range of molarity with in the physiological pH range (pH 6.0–8.0) was assessed to determine the best protein extractant for pork lean meat. The individual proteins in the extracts were identified by electrophoresis. The highest protein extractabilities at pH 7.0 for NaCl, KCl and LiCl were observed at 1.2, 1.1, and 1.1 M, respectively. There was no significant difference in protein extractability for KCl and LiCl within physiological pH range. NaCl had a significant increase of its protein extractability as pH increased from 6.0 to 6.5 followed by a relatively constant extractability. The NaCl had the highest protein extractability followed by LiCl and KCl. The maximum number of proteins (26 bands) was found at the optimum concentration of each salt. However, resolution and clarity of bands were better in NaCl extracts. The pH variation does not affect the number and the intensity of the bands.     

Immersion chilling of hot cut, vacuum packed pork primals

Hot-cutting and immersion chilling of pork was compared with a conventional air chilling process. The right sides of eight pig carcasses were cut into primals whilst hot, vacuum packed and chilled in sodium chloride brine at 0°C, whilst the left sides were chilled conventionally in air at 0°C and 1 m/s, before being similarly cut and vacuum packed. The primals from both treatments were then stored in air at 0°C for either 24h or 15 days post mortem. The immersion process achieved an average saving in weight loss of 1·9% after both storage periods, and took between 2·5 and 3·5 h less than the conventional process to reduce meat temperatures to 7°C. It did, however, produce significantly tougher meat after 24 h, although not after 15 days. Sensory evaluation of odour and appearance suggested a reduced shelf-life and a darker meat coloration for immersion chilled pork.     

ULTRA-RAPID CHILLING: CHILLING RATE EFFECTS ON THE APPEARANCE OF LAMB CARCASSES AND TENDERNESS OF LAMB CHOPS

The effects of different chilling rates on the visual attributes of lamb carcasses and the tenderness of lamb chops were investigated. Carcasses (n=72) were chilled at -20C, -10C, -4C or + 4C. After chilling all carcasses were stored at +4C for up to 8 days. Samples were taken at 2, 6 and 9 days postmortem for sarcomere length, Warner-Bratzler shear force and sensory analysis. Carcasses were visually appraised at 2, 6 and 9 days postmortem for fat color, flank color, visible vein color, wetness and overall acceptability. Carcasses chilled at -20C had significantly higher Warner-Bratzler shear force values than the other chilling treatments at 2 and 6 days but not at 9 days postmortem. No difference (P> 0.05) was found in Warner-Bratzler shear force or sensory tenderness between any of the treatments by 9 days postmortem. Carcasses did not differ (P>0.05) in fat color, flank color or overall acceptability at any stage postmortem. Carcasses chilled at -20C had slightly darker (P< 0.05) vein color at 2 days postmortem but this was not evident by 6 days postmortem. Carcasses that were chilled at -20C had significantly lower evaporative weight losses than carcasses in any of the other treatments. Rapid chilling did not adversely affect the tenderness of lamb chops or appearance of lamb carcasses at 9 days postmortem compared with conventional chilling.     

The effects of different chilling methods on meat quality and calpain activity of pork muscle longissimus dorsi

The objective of this study was to investigate the effects of conventional chilling (0 to 4 °C), rapid chilling (RC, -20 °C for 30 min, followed by 0 to 4 °C), and short-duration chilling (0 to 4 °C for 30 min, followed by 25 °C) on meat quality and calpain activity of pork muscle longissimus dorsi (LD). The muscle quality characteristics pH, color, cooking loss, pressing loss and tenderness, and calpain activities were measured 0-, 3-, 12-, and 24-h postmortem. Results show that the RC resulted in a faster temperature decline of the muscle, and prevented the meat pH and Commission Internationale de l'Eclairage L* value from declining during postmortem aging. RC also reduced meat cooking loss and pressing loss compared with the other two chilling methods. However, the chilling methods did not significantly affect meat shear force. During the first 24-h postmortem, there was not a noticeable change in the activity of m-calpain. But μ-calpain activity decreased regardless of chilling method. In the rapidly chilled carcasses, μ-calpain activity remained the same 3- and 12-h postmortem. However, in the short-duration chilled and conventionally chilled carcasses, the activity was visibly reduced. At 24-h postmortem, no clear zones on the gel were observed in all three treatments. PRACTICAL APPLICATION: Conventional and RC methods are commonly used for pork in commercial practice nowadays. Compared with conventional chilling, the effect of RC on quality parameters of pork varies. In recent years, short-duration chilling (SC) is widely used in many Chinese pig slaughtering facilities. However, few researchers have studied the effect of SD on pork quality. Therefore, the present study investigated the effect of different chilling methods on functionalities or quality of chilled pork meat.     

Effects of Electrical Stimulation on the Functional Properties of Lamb Muscle

One side from each of eleven lamb carcasses was electrically stimulated (60 Herz alternating current at 240v followed by 420v) within 45 min postmortem. Three carcasses (stimulated and respective control sides) were rapidly chilled (1°C), three carcasses received a delayed chill (12°C until pH 6.0 was attained, then excision and 1°C), and three carcasses were slowly chilled (12°C). Measurements beginning at 44 hr postmortem showed that stimulation increased the sarcomere lengths but had few consistent or significant effects on water-holding capacity, protein solubility, emulsifying capacity, gel strength, cooking loss, or binding strength. The remaining two carcasses were rapidly chilled and their meat was manufactured into frankfurters. The emulsion stability was slightly improved by stimulation but smokehouse weight loss, Warner-Bratzler shear force, penetration force, cooking loss, and sensory characteristics were unaffected.     

不同排酸方式对巴美肉羊肉品质的影响

随机选择相同饲养条件下的巴美肉羊,以非吊挂排酸和吊挂排酸两种方式进行对比实验,分别测定其不同部位0.5～48h pH值的变化规律和24～72h剪切力的变化规律。结果显示：非吊挂排酸羊股二头肌、背最长肌、臂三头肌均在宰后6h或8h的pH值显著小于吊挂排酸羊（P〈0.05）。非吊挂排酸羊在不同时间pH值没出现显著下降,吊挂排酸羊在不同时间pH值易出现显著下降。通过对巴美肉羊宰后24～72h时间内指定部位肌肉剪切力变化规律得出吊挂排酸羊3个指定部位剪切力总体要比非吊挂排酸羊剪切力低。在吊挂排酸方式下背最长肌剪切力最易出现显著变化。     

Inhibition of the proliferation of myeloma cells by the meat origin strain Enterococcus faecium CH3

Sides of 31 non-stimulated carcasses of young bulls were subjected to the muscle stretching methods Tenderstretch (TS) by pelvic bone suspension or Tendercut (TC) with two skeletal cuts or served as controls by traditional Achilles tendon suspension. The sides were chilled at fast and medium rates, resulting in temperatures of 4-5 and 9°C in the m. longissimus dorsi (LD) at 10 h post mortem. The LDs were examined for sarcomere length, Warner-Bratzler peak shear force and sensory properties after 8 days of ageing at 4°C. At the fast chilling rate, TS and TC increased sarcomere lengths, reduced shear force and improved sensory tenderness of the LDs compared to the controls (P<0.05). At the medium chilling rate, sarcomere lengths increased (P<0.05), but no significant differences were found in shear force or sensory tenderness (P>0.05) of the muscles due to stretching. However, the medium chilling rate was efficient in producing tender LDs without applying muscle stretching methods. TS and TC are feasible alternatives for improving overall tenderness and reducing variation in tenderness of beef LD at cold shortening chilling conditions.     

Effect of chilling applied to suckling lamb carcasses on hygienic,physicochemical and sensory meat quality

The effect of post mortem temperature treatment on suckling lamb carcass and meat quality was study. Conventional (2 °C for 24 h), ultra-rapid (− 20 °C for 3.5 h, 2 °C until 24 h) and slow chillings (12 °C for 7 h, 2 °C until 24 h) were compared. Total viable counts (TVC), weight losses, and pH and temperature falls were recorded on carcasses. Meat colour, water holding capacity (WHC), Warner-Bratzler shear force, sarcomere length and sensory analysis were evaluated in M. longissimus. Ultra-rapid treatment reduced TVC and weight losses. The pH decline was faster in slow chilled carcasses than in faster chilled carcasses. No significant differences were found for colour and WHC. Slow treatment carcasses showed significantly lower shear force and higher sarcomere length. In the sensory analysis, tasters also rated the early post mortem slow-treated meat as more tender, less fibrous and chewy. Therefore, delay chilling in suckling lamb carcasses made it possible to obtain meat with better organoleptic characteristics, without affecting weight loss or hygienic quality.     

FURTHER INVESTIGATIONS ON THE ULTRA-RAPID CHILLING OF LAMB CARCASSES

Commercial chilling methods of lamb have taken account of the possibility of cold-shortening and so rapid chilling rates, in the absence of electrical stimulation, have not been used. The effects of three chilling regimens (conventional, intermediate and ultra-rapid) on lamb carcasses were investigated. Lamb loins from carcasses chilled under ultra-rapid conditions (-20C and 1.5 m/s for 3.5H) were as tender as those from carcasses that were chilled under intermediate (-2C) and conventional conditions (4C). Loins were as tender at 24 h as they were at 5 days of storage. Weight losses in the carcasses were significantly reduced as a result of using ultra-rapid chilling compared to conventional chilling (0.57% as opposed to 1.48%). The change in pH of carcass loins in all chilling regimens, from 1h postmortem to 4h, was from about 6.5 to 6.0. This rapid glycolysis is discussed in relation to the tenderness of the meat that was produced by all of the chilling regimens. The ultra-rapid chilling regimen has commercial potential because it produces tender meat with very low evaporative weight losses.     

The ultra-rapid chilling of lamb carcasses

Experiments were carried out on the effects of chilling lamb carcasses very rapidly in a pre-rigor condition. The chilling regime which was finally used was to cool the carcasses at an ambient temperature of -20°C and an air speed of 1·5 m/s for 3·5 h. Examination of striploins from carcasses subjected to this chilling regime showed that, after 7 day's storage, the meat was as tender as that from carcasses which had been conventionally chilled at 4°C for 24 h There were significant reductions in weight loss as a result of ultra rapid chilling, compared to conventionally chilled carcasses. The reductions obtained after 24 h varied between 0·8 and 0·9%, depending on whether the carcasses were washed or unwashed.     

EARLY POSTMORTEM MUSCLE SHORTENING AND TENSION IN RELATION TO TENDERNESS IN BEEF M. LONGISSIMUS

The purpose of this study was to investigate muscle tension and shortening in relation to tenderness in beef M. longissimus. Initially, an intercalibration of six identical rigormeters using a polyacrylamide standard showed that the rigormeters gave reproducible results. This means that the rigormeter is a potentially valuable tool in studies of postmortem muscle tension and shortening. Tension and shortening of M. longissimus from 24 bulls carcasses exposed to two different chilling regimes were measured 1.5 to 20 h postmortem in the rigormeters. The muscle samples were separated into three groups; fast chilled (all tough), slow chilled (tough) and slow chilled (tender). On average, both the developed tension and accumulated shortening of muscle strips during this period were highest in tender, slow chilled samples and lowest in fast chilled samples. There was a relationship between glycolytic rate and the muscle contraction process, as the fast glycolyzing muscles exerted the fastest development of tension and contraction. This study indicates that tension and, shortening, as measured in the rigormeter, is related to WB shear force measured in aged meat.     

快速冷却对山羊背最长肌肉品质的影响

6头云南地方云岭黑山羊(羯羊)屠宰、劈半后,左半胴体进行常规冷却(0～4℃冷却24h,相对湿度90～95%),右半胴体进行快速冷却(-20℃,冷却1.0h后,转入0～4℃冷却23h,相对湿度90～95%),取背最长肌,测定相关肉品质指标。结果显示,样品经3d成熟,快速冷却的羊肉剪切力显著低于常规冷却(P<0.05),快速冷却的羊肉嫩度的感官评分显著高于常规冷却(P<0.05),而pH、肉色、蒸煮损失等指标两种冷却方式无显著差异。研究表明,本试验采用的快速冷却方式对山羊肉的嫩度有显著改善效果。     

减盐火锅底料对牛肉食用品质及钠、钾含量的影响

以牛肉（牛里脊肉）为原料,在不同比例NaCl和KCl组成减盐配方的火锅底料中涮制不同时间,比较KCl替代比例及涮制时间对牛肉感官评价、剪切力、蒸煮损失率的影响,并探究牛肉在减盐火锅底料中涮制前后盐含量、钠含量与钾含量的变化规律。结果表明：牛肉在NaCl、KCl质量比7∶3的减盐火锅底料中涮制各时间点感官评分均最高,在不同比例NaCl和KCl组成的减盐火锅底料中涮制,剪切力均随涮制时间的延长而增加,在涮制160 s后增加最显著;牛肉盐含量与钠、钾含量均随涮制时间的延长而显著增加,相同涮制时间下牛肉钠含量随减盐配方中KCl替代比例的升高而降低,且钠含量降低比例与KCl替代比例接近。减盐火锅底料能在不影响牛肉风味与食用品质的前提下,降低火锅钠摄入量30%左右,推荐减盐火锅底料KCl替代比例为30%,推荐牛肉涮制时间为120 s。     

延迟冷却对牛肉品质及超微结构影响的研究

本文研究了常规冷却与延迟冷却对中国杂交黄牛(鲁西黄牛×西门塔尔)宰后冷却过程中牛胴体pH值、温度变化、胴体冷却失重、肉色及成熟过程中剪切力值、背最长肌汁液损失、蒸煮损失、保水性、肌原纤维结构变化的影响.结果表明延迟冷却能减缓牛胴体温度的下降速率(P＜0.05),加快牛胴体pH值的降低(P＜0.05),提高牛背最长肌的嫩化速率,改善肉色(P＜0.05),但加剧了汁液损失、蒸煮损失,降低了保水性(P＜0.05).延迟冷却对成熟0d、3d时的肌原纤维结构影响显著(P＜0.05),延迟冷却组的肌节长度明显长于对照组的肌节长度.     

Kappa-Carrageenan, Sodium Chloride and Temperature Affect Yield and Texture of Structured Beef Rolls

Structured lean beef rolls (4–5% fat), formulated with 33% added water, 1% sodium chloride and 0.35% sodium tripolyphosphate and cooked to 63°, 73° and 83°, had low cook yields and poor texture and bind. Kappa-carrageen an (KC) added at 0.5–1% and NaCl at 2–3% increased cook yield and improved textural properties (bind, force to fracture, hardness). Rolls with 1.0% KC and 3% NaCl had the highest cook yield (154% meat weight basis) and the highest values for force to fracture and hardness. Cook yield decreased and hardness increased with increased cooking temperature. Effects of KC on yield and texture were most pronounced at the lowest NaCl level (1%) and the highest temperature (83°). KC also reduced purge of vacuum-packaged slices during refrigerated storage.