Response Surface Methodology Approach to the Optimization of Boneless Ham Yield

Three ham processing variables (tumbling, tenderization, and temperature) were optimized for cooked yield of both pre- and post-rigor ham muscle (semimembranous). Through response surface methodology (RSM), it was determined that the optimum tenderization (80-100% of knife blade capacity) and processing temperature (14-16°C) conditions were approximately the same for both pre- and post-rigor muscle. However, the optimum level of continuous vacuum tumbling (total revolutions) was much lower for pre-rigor muscle (750 rev) than post-rigor muscle (3500-4000 rev).     

Rigor Condition, Tumbling and Salt Level Influence on Physical, Chemical and Quality Characteristics of Cured, Boneless Hams

Influence of pre- or post-rigor conditions, short or long-time tumbling and 1.25 or 2.25% salt on the physical and chemical properties, quality and yield of hams were examined. Curing pre-rigor did not inhibit rigor, but long term tumbling slowed rigor development. Cell disruption and salt-soluble proteins extraction were enhanced more by processing pre-rigor than post-rigor. Pre-rigor intermittent tumbling for 18 hr produced a more uniform cured color and a more desirable slice appearance. Cohesiveness was improved by 18 hr intermittent tumbling. Bind strength at 6 hr intermittent tumbling of pre-rigor tissue was equivalent to that of 18 hr intermittent tumbling, suggesting that curing pre-rigor could reduce tumbling time.     

Influence of Pre-Rigor Processing, Mechanical Tenderization, Tumbling Method and Processing Time on the Quality and Yield of Ham

Eight market weight hogs with similar genetic and management background were conventionally slaughtered with the resulting sixteen pork carcass sides randomly assigned to treatments. Four treatments at 2 levels each (2⁴ factorial design) included muscle condition [pre-rigor (hot) or post-rigor (chilled)], mechanical knife blade tenderization [no tenderization or tenderization], vacuum tumbling [continuous or intermittent], and the processing delay time between vacuum tumbling and further processing [no delay time or 20-hr delay]. Results indicated that pre-rigor processed meat tissue exhibited higher pH, water-holding capacity (WHC), and cooked yield characteristics. Mechanical knife blade tenderization consistently increased protein content of the uncooked meat exudate, cooked yield, and palatability characteristics. Tumbling method and processing time had little influence on either uncooked or cooked meat characteristics.     

滚揉和腌制液成分对肉块类西式火腿质构的影响

研究了滚揉时间、腌制液中食盐浓度和三聚磷酸钠(STPP)浓度3因素对肉块类西式火腿的质构影响。采用冷鲜的猪里脊肉为原料,每个因素3个水平,按照L27(313)考虑交互作用的正交实验设计,进行滚揉和腌制液的配制,并制作肉块类西式火腿。利用质构仪测定火腿的硬度和弹性。滚揉时间、腌制液中食盐浓度、三聚磷酸钠浓度以及他们的交互作用对火腿的硬度影响显著(p<0.05),增加滚揉时间不能显著提高火腿的弹性,反而增加电能的消耗,食盐浓度和滚揉时间的交互作用对产品弹性的影响显著(p<0.05),并且其交互效益大于食盐浓度和三聚磷酸钠的单独效益。当滚揉时间8h,腌制液中食盐浓度10%,STPP浓度2.0%时硬度品质最优。当滚揉时间4h,腌制液中食盐浓度8%,STPP2.0%时弹性品质最优。     

Effect of Tumbling and Tumbling Temperature on Total Aerobic Plate Counts (Incubated at 25°C) and Quality of Boneless, Cured Hams

The effects of intermittent tumbling (up to 18 hr) and processing temperature (25°C or 3°C) on internal temperature and exudate total aerobic plate counts incubated at 25°C (ATPC) in boneless, cured hams were determined. The design used 80 hams in five replicates involving four treatment groups (tumbled at 25°C tumbled at 0°C, control held at 25°C and control held at 0°C). The significant (P < 0.01) tumbling effect on the rise in internal ham temperature occurred after 3 hr, but only accounted for a difference of 1.26°C-1.32°C, independent of processing temperature. While tumbling significantly improved the cooked yield by 3.45%, processing at 25°C rather than at 0°C resulted in a significant (P<0.05) yield reduction of 2.15% after 9 hr of processing. The exudate ATPC was significantly (P<0.01) reduced after 18 hr of tumbling.     

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.     

Penetration of hydrolysed soy protein-added brine and its effect on yield and pH of beef steaks from the biceps femoris muscle

This study was aimed to evaluate the penetration behaviour of different brines with tumbled beef steaks from the biceps femoris muscle, specifically their interactions with pH and effects on yield. Six muscles from different animals, divided into origin (OP) and insertion (IP) portions, were cut into 60 steaks of 2.5 cm thickness and tumbled for 30 or 60 min. The steaks were tumbled with two brines, with (WTB/HSP) or without (WTB) hydrolysed soy protein (HSP), and steaks that were not tumbled with brine or water were used as controls. Brine penetration was verified by measuring the amount of dye-containing brine (absorbance at 627 nm) recovered from homogenates of four thin (2 mm) slices from the surface of the beef steaks after tumbling. The WTB/HSP steaks exhibited greater (P < 0.05) brine penetration when tumbled for 60 min than for 30 min. The OP steaks showed greater yield and lower pH (P < 0.05) than IP steaks. HSP-added brine increased the water absorption and retention in the first slices of the steaks, and its efficiency was increased with a longer tumbling time. The portion of the biceps femoris muscle used influenced brine absorption and retention, impacting meat yield.     

呼吸式滚揉工作时间对调理牛肉品质的影响

与传统真空滚揉相比,呼吸式滚揉具有处理时间短、腌制效率高等优点。本研究以牛肉为原料,探究呼吸式滚揉工作时间（滚揉10 min/暂停5 min、滚揉15 min/暂停5 min、滚揉20 min/暂停5 min、滚揉25 min/暂停5 min）对调理牛肉品质的影响。结果表明,随着滚揉工作时间的增加,腌制吸收率、水分含量和pH均呈现先上升后下降的趋势,而蒸煮损失、离心损失及剪切力则呈现先下降后上升趋势,均在滚揉20 min/暂停5 min时达到最佳。与此同时,滚揉20 min/暂停5 min组样品具有最高的a*值和持水能力。扫描电镜结果表明肌纤维降解程度随着滚揉工作时间增加而加大,与电泳结果相一致。因此,滚揉20 min/暂停5 min为最佳滚揉参数,显著提高了调理牛肉的出品率,并改善了产品的品质特性（P<0.05）,在肉品工业中具有良好的应用前景。     

A study of the ice crystal sizes of red muscle of pre-rigor Atlantic salmon (Salmo salar) fillets during superchilled storage

Pre-rigor salmon fillets were superchilled in an impingement freezer and stored at −1.7 ± 0.3 °C for 29 days. The objective of this work was to study the ice crystal sizes in red muscle of pre-rigor salmon fillets that were partially frozen at fast (−30 °C, 227 W/m² K, 2.1 min) which is referred to as process F and slow (−20 °C, 153 W/m² K, 4.2 min) which is referred to as process S during superchilled storage. It was observed that the size of intracellular ice crystals in pre-rigor muscles at faster superchilling rate was significantly (p < 0.05) smaller than that at slower superchilling rate. The size of ice crystals formed in pre-rigor muscle was significant (p < 0.05) smaller than that formed in post-rigor muscle. It was also observed that the size of intracellular ice crystals formed in pre-rigor red muscles was significant smaller than that in white muscle. In addition, a large number of small ice crystals are formed within the muscle during partial freezing of pre-rigor muscle compared to post-rigor muscle. Future research should focus on tests of the quality parameters separately in red and white muscles (pre- and post-rigor) during superchilled storage of food products in order to understand more about their characteristics (quality and shelf life).     

真空滚揉工艺优化对复合低钠替代盐调理牛肉的品质改善

为了满足复合低钠替代盐调理牛肉的工业化生产需求,该研究在单因素试验基础上,研究液料比、滚揉时间、真空度对腌制吸收率和蒸煮损失率的影响,通过中心组合（Box-Behnken）和响应面法确定调理牛肉真空滚揉的最佳工艺,并对静置腌制和滚揉腌制调理牛肉的质构特征、剪切力、水分分布、微观结构进行分析。结果所得最佳滚揉工艺参数：液料比32%、滚揉时间3.0 h、真空度0.06 MPa,在此条件下得到腌制吸收率24.65%,蒸煮损失率为26.39%。滚揉组调理牛肉的硬度、弹性、咀嚼性和剪切力均显著低于静腌组（P<0.05）,不易流动水和自由水弛豫时间显著低于静腌组（P<0.05）,并且自由水弛豫峰面积显著高于静腌组（P<0.05）。扫描电镜图显示,滚揉组的肌原纤维结构更加松散,并且有碎片化结构附着表面。结果表明,滚揉处理能够改善调理牛肉的质构特征,提高嫩度,提高保水性,微观上使肌原纤维产生碎片化结构。该研究为复合低钠替代盐调理牛肉的滚揉工艺提供技术支持,为营养型低钠调理肉制品工业化生产提供理论依据。     

Effects of pre-rigor injection of sodium citrate or acetate, or post-rigor injection of phosphate plus salt on post-mortem glycolysis, pH, and pork quality attributes

Forty pork carcass sides were assigned to one of four treatments: pre-rigor citrate (CIT) or acetate injection (ACE); post-rigor phosphate and salt injection (PHOS); and non-injected control (CON). Loins in 20 sides were injected at 50 min post-mortem with 4% solutions of CIT or ACE to approximately 110% of projected loin weights, and 10 loins were injected at 24 h post-mortem to 106.6% with a solution of 4.4% PHOS and 2.2% salt. Although CIT increased pH (P < 0.05), neither CIT nor ACE altered (P > 0.05) glycolytic metabolite concentrations. The pH increase in muscles from the CIT treatment was most likely due to its buffering ability rather than to its glycolytic inhibition. Pre-rigor CIT injection improved tenderness without the detrimental effects on color or flavor found with PHOS, but neither CIT nor ACE altered glycolytic metabolites or improved firmness, wetness, or fresh visual color over CON. Poor flavor attributes of the ACE treatment will hinder its use as an ingredient for pork enhancement solutions.     

Effects of high-intensity high-frequency ultrasound on ageing rate, ultrastructure and some physico-chemical properties of beef

High-intensity and high-frequency ultrasound was tested for its ability to accelerate meat ageing and increase beef tenderness. Samples (≈50g) of semimembranosus muscles from 8 cull cows were assigned to ultrasonic treatment (2.6MHz; 10W/cm(2); 2 ×15s) either pre-rigor (day 0, pH 6.2) or post-rigor (day 1, pH 5.4). When applied pre-rigor, ultrasound induced a slight delay in rigor mortis onset, a stretching (12-15%) of the sarcomeres (p<0.05), an ultrastructural alteration in the Z-line region and an immediate increase (around 30%) in the release of calcium in the cytosol (p<0.05). However, no conclusive effect on meat ageing rate was observed. Post-rigor ultrasonic treatment did not induce any structural modification but slightly improved the ageing index after 6 days (p<0.05). However, no improvement in the final (day 14) ageing index was observed compared to the controls. As ultrasound had also no effect on the thermal stability of collagen, at both postmortem times, no improvement in meat tenderness can be expected under the conditions used.     

Hot-boning, Tumbling, Salt and Chopping Temperature Effects on Cooking Yield and Acceptability of Emulsion-type Pork Sausage

Hot-boned or chilled pork with addition of 2% or 3% salt was used to prepare emulsion-type pork sausage. Different tumbling periods and a variety of chopping temperatures were evaluated. Emulsifying capacity (EC), water-holding capacity (WHC), pH, total plate count (TPC) and organoleptic properties were determined. Hot boned pork with 3% added salt had higher EC, pH, WHC, cooking yield and lower TPC than chilled meat samples with 2% added salt. As chopping temperature increased, WHC decreased and TPC increased. However, an intermediate chopping temperature of 12.8°C produced superior yield.     

Water properties and salt uptake in Atlantic salmon fillets as affected by ante-mortem stress,rigor mortis,and brine salting: A low-field H NMR and H/Na MRI study

A low-field (LF) ¹H NMR T₂ relaxation and ²³Na/¹H MRI study was performed on Atlantic salmon to study the effect of ante-mortem handling stress and rigor mortis on muscle water properties and subsequent post-rigor salting. Compared to rested fish, exhausted fish exhibited a more rapid and stronger development of rigor mortis. This resulted in significant differences in post-rigor water-holding capacity and salt uptake. By LF NMR T₂ relaxation analysis significant differences in water distribution according to (1) ante-mortem handling, (2) fillet location, and (3) brine salting were detected. Furthermore, ²³Na MRI revealed differences between the two treatments in fillet salt distribution, where the salt penetration in exhausted fillets was more pronounced. By combining ¹H and ²³Na MR images, the salt diffusion and distribution seemed to be highly affected by the distribution of fat.     

Effects of transport time and rest period on the quality of electrically stimulated male cattle carcasses

Ground, pre-salted, pre-rigor semimembranosus muscles of beef were subjected to three treatments A=rapid carbon dioxide (CO(2)) chilling, B=slow CO(2) chilling and C=air chilling, and compared to a control D=slow air chilling of muscles, which were subsequently ground and salted post-rigor. Meat of the pre-rigor treatments A, B and C had higher pH values during processing, lower cooking loss, firmer texture and a lighter yellowish external colour of cooked patties than the post-rigor control D (p<0.05). The two CO(2) chilling regimes A and B had no detrimental effects on the functional properties of the pre-rigor meat. Sarcomere lengths did not differ in meat of the four treatments (p>0.05), indicating that early pre-salting protected the meat from cold shortening during rapid temperature decline. A process combination of grinding, followed by immediate pre-salting and CO(2) chilling within 312h post-mortem of non-stimulated beef muscles is likely to yield superior binding properties of cooked patties and similar ground beef products.     

滚揉腌制条件对猪肉加工特性的影响

研究了滚揉时间和食盐浓度,滚揉时间和焦磷酸盐（PP）浓度以及PP、三聚磷酸盐（TPP）、六偏磷酸盐（HMP）和滚揉时间对肉块腌制液吸收保留和蒸煮得率的影响。以猪里脊肉为研究材料,垂直于肌纤维方向切成2cm肉块和腌制液混合滚揉腌制,研究不同处理条件下,腌制液吸收百分比、腌制液吸收率、腌制液保留量、腌制液保留百分比及蒸煮得率的变化情况。试验结果表明,随着滚揉时间、食盐浓度和PP浓度增加,腌制液吸收百分比逐渐增加,分别达到了38．7％和38．2％,但腌制液吸收率在滚揉2h内是较大的,随着滚揉时间的延长逐渐减小。不同磷酸盐都提高了腌制液的吸收百分比和腌制液保留量,它们对腌制液吸收百分比和保留量的影响效益顺序是：PP〉TPP〉HMP。除了空白处理组外,随着滚揉时间、食盐浓度和PP浓度的增加,蒸煮得率逐渐增加,分别达到了94．6％和113．5％。不同磷酸盐都提高了滚揉腌制肉块的蒸煮得率,它们对蒸煮得率的影响效益顺序是PP〉TPP〉HMP。随着滚揉时间的延长,蒸煮得率分别达到了106．7％、102．5％、88．2％。     

Effects of Low Frequency Ultrasound on Properties of Restructured Beef Rolls

The effects of low frequency ultrasound on exudate yield, breaking strength, cooking yield, water-holding capacity, color, and muscle microstructure were investigated by exposing pieces of lean muscle to slow tumbling and low frequency ultrasonic waves. Results indicated that beef rolls exposed to low frequency ultrasound without added salt were superior in breaking strength and cooking yield to those tumbled with neither ultrasound nor salt and were comparable in breaking strength, cooking yield, exudate yield and water-holding capacity to those tumbled with salt and no ultrasound exposure. Furthermore, the beef rolls exposed to ultrasound and no salt were superior in color to those to which salt was added. Low frequency ultrasound caused muscle fiber disruption and separation of up to approximately 1 cm in depth in muscle micro-structure in the pieces of lean muscle.     

Lipid Oxidation in Cooked Pork as Affected by Vitamin E, Cooking and Storage Conditions

The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two-way and three-way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.     

Study of the quality characteristics in cold-smoked salmon (Salmo salar) originating from pre- or post-rigor raw material

Improved slaughtering procedures in the salmon industry have caused a delayed onset of rigor mortis and, thus, a potential for pre-rigor secondary processing. The aim of this study was to investigate the effect of rigor status at time of processing on quality traits color, texture, sensory, microbiological, in injection salted, and cold-smoked Atlantic salmon (Salmo salar). Injection of pre-rigor fillets caused a significant (P<0.001) contraction (-7.9%± 0.9%) on the caudal-cranial axis. No significant differences in instrumental color (a*, b*, C*, or h*), texture (hardness), or sensory traits (aroma, color, taste, and texture) were observed between pre- or post-rigor processed fillets; however, post-rigor (1477 ± 38 g) fillets had a significant (P>0.05) higher fracturability than pre-rigor fillets (1369 ± 71 g). Pre-rigor fillets were significantly (P<0.01) lighter, L*, (39.7 ± 1.0) than post-rigor fillets (37.8 ± 0.8) and had significantly lower (P<0.05) aerobic plate count (APC), 1.4 ± 0.4 log CFU/g against 2.6 ± 0.6 log CFU/g, and psychrotrophic count (PC), 2.1 ± 0.2 log CFU/g against 3.0 ± 0.5 log CFU/g, than post-rigor processed fillets. This study showed that similar quality characteristics can be obtained in cold-smoked products processed either pre- or post-rigor when using suitable injection salting protocols and smoking techniques.     

TUMBLING REGIME EFFECTS ON THE PROCESSING CHARACTERISTICS AND TENDERNESS OF COOKED ROAST BEEF

Tumbling prior to injection and different tumbling regimes was investigated to improve the processing characteristics of beef mini roasts. Six inside round muscles (semimembranosus muscle, with adductor and gracilus removed) were cut into six 700 ± 50 g roasts. The roasts were injected 125 or 150% over original weight. The tumbling regime incorporated tumbling prior to injection (pretumbling) and two postinjection tumbling regimes (continuous versus intermittent). Tumbling prior to injection improved (P < 0.05) injection pick up, retention, yield and tenderness, however, with mini roasts there were no differences between continuous and intermittent tumbling. Further research is needed on processing technologies to improve efficiencies in producing these mini roast beef.