不同电击昏方式对猪肉品质的影响

研究了不同电击昏方式对猪肉色泽、系水力的影响及其与PSE肉发生率之间的关系。对48头猪分3个组分别进行不电击昏（对照）,手工头部电击昏和自动头胸电击昏3种处理。结果表明电击昏使宰后pH下降较快,肉色明亮度和红色度增大,肌肉系水力下降,断骨率增多,PSE肉发生率增大;采用手工头部电击昏系统和自动头胸电击昏系统处理的猪其PSE肉发生率分别为25％和12．5％,断骨率分别为8．33％和2．67％。自动头胸电击昏系统显著提高了猪肉的品质。     

致昏电压对兔肉品质的影响研究

采用100、75、65、55V和人工致昏(对照组)的宰杀方式,研究其对兔肉品质的影响,结果表明:不同致昏电压对兔肉pH值的影响差异不显著(p>0.05),只有75V致昏组与100V致昏组间宰后1h的背最长肌pH值差异显著(p<0.05);宰后1h,不同致昏电压对兔背最长肌的肉色亮度L*值、红度a*值、黄度b*值和后腿肉的L*值、a*值的影响差异不显著(p>0.05);宰后24h,75V致昏组的肌肉颜色鲜红,而人工致昏组和100V致昏组的肌肉颜色较苍白;100V致昏组的滴水损失最大,为3.738%,而75V致昏组的最小,为2.420%;蒸煮损失最大的为100V致昏组,最小的为55V致昏组,其次是75V组;肌肉嫩度最好的是75V致昏组,最差的是人工致昏组。     

不同浓度卡拉胶对猪肉品质影响的研究

试验研究了不同浓度卡拉胶对猪肉的感官品质、色泽、保水性、蒸煮损失率及嫩度等品质指标的影响。结果表明,添加不同浓度的卡拉胶后,对猪肉的感官品质有一定的影响,对猪肉的色泽有负面的影响,不同浓度影响效果不同,一般高浓度的对猪肉感官品质的负面影响较大。卡拉胶浓度与猪肉的感官评分、剪切力之间的回归方程均具有统计学上的显著意义,与猪肉的色差、保水性及蒸煮损失率之间的回归方程不具有统计学上的显著意义。     

宰前处理和冷却方式对猪肉品质的影响

本文对宰前处理方式、致晕方法和冷却方式对猪肉品质(肉色、滴水损失/持水性-WHC和电导率)的影响进行了比较总结,旨在对屠宰行业在控制肉品质,减少PSE发生方面提供参考。     

上市日龄和性别对胡须鸡肉品质的影响

为探究不同上市日龄和性别对胡须鸡肉品质的影响，本试验以胡须鸡（公鸡，80、90、100、110 d；母鸡，100、120、140、160 d）为研究对象，对其屠宰性能、鸡皮微观结构、肌肉肉色、胸肉pH_{45 min}、胸肉肌纤维特性和保水性进行比较分析。结果表明，胡须鸡的活重、毛重、血重均随日龄的增长而显著增长（P<0.05），而性别对肉质的影响也很大程度上依赖胡须鸡的上市日龄，总体而言本研究中胡须鸡的肉用性能良好。在60±1 ℃浸烫温度下，80 d公鸡和100 d母鸡鸡皮角质层被破坏，而性成熟后的公鸡（90~110 d）和母鸡（120~160 d）的鸡皮角质层则完整保留。同性别样品的胸肉肌纤维直径均随日龄的增加而显著增加（P<0.05），肌纤维密度则随日龄的增加而显著减少（P<0.05）。滴水损失、蒸煮损失均在同性别组中表现出随日龄增加而降低的趋势，性成熟前（公鸡80～90 d，母鸡100～120 d）的滴水损失在不同日龄间差异不显著（P>0.05），而性成熟后（公鸡90～110 d，母鸡120～160 d）的滴水损失在不同日龄间差异显著（P<0.05）；蒸煮损失在公鸡组从80~110 d其数值降低了约50%，而蒸煮损失在母鸡组从100~160 d其数值降低了约40%。综合屠宰性能、鸡皮微观结构、肌肉肉色、胸肉pH_{45 min}、胸肉肌纤维特性和胸肉保水性的分析，可知散养胡须鸡公鸡和母鸡在上市日龄范围内均具有较好的肉用性能，适合于肉鸡的开发和生产。     

含磷酸盐的香辛料液对猪肉品质的影响

本文研究了含磷酸盐的香辛料液对猪肉嫩度和感官品质的影响。将肉样分成4个组,分别注射含不同浓度磷酸盐(0.0%,0.2%,0.3%,0.4%)的香辛料液。肉样注射后在4℃冷藏72h,测定嫩度,pH值,成品率和感官指标,结果表明:试验组的嫩度、成品率和风味明显高于对照组(P<0.05),且磷酸盐浓度越高,效果越明显,但各组间猪肉颜色没有呈现出明显差异。研究表明将磷酸盐溶解于香辛料液中注入猪肉可以改善肉的品质。     

屠宰因素对肌肉保水性影响的研究进展

肉的保水性是肉的重要品质指标之一,与肌肉的其它品质指标如颜色、风味、嫩度等有着密切联系。研究肌肉保水性的影响因素对于改善肉的整体品质和减少因滴水损失造成的经济损失具有重要价值。影响肌肉保水性的因素很多,而目前国内相关研究很少,本文综述了近年来屠宰因素对肌肉保水性影响方面的国内外最新研究进展。     

亚麻籽粉对猪肉灌肠品质的影响

主要考察亚麻籽粉对猪肉灌肠品质的影响。研究亚麻籽粉对猪肉灌肠的硬度、弹性、咀嚼性、内聚性、黏着性、胶黏性、嫩度以及色泽的影响。结果表明:亚麻籽粉在0.3%~0.5%添加量时(以原料肉计)可获得具有较高品质的猪肉灌肠。亚麻籽粉有希望成为新一代天然食用胶体资源。     

不同日龄獭兔肉品质及理化特性比较

研究了不同日龄獭兔肉品质和理化特性差异,为今后獭兔肉加工和分级提供参考。随机选取日龄分别为4个月、6个月和8个月,健康无病,发育正常的美系獭兔各7只,以肉色和嫩度为感官指标,以滴水损失率、蒸煮损失率、肌纤维密度和纤维直径及p H为理化指标,比较了不同日龄兔肉的食用品质和理化性质的差异。结果表明:从4月龄至8月龄,随着日龄的增长,獭兔肉的亮度值(p0.05)、红度值(p0.05)逐渐增大,滴水损失明显升高,剪切力值逐渐增大,肌纤维直径增粗(p0.05),肌纤维密度减小;宰后,Calpain酶活力随兔龄的增长呈下降趋势(p0.05),8月龄兔肉中Caspase-3酶活低于4月龄和6月龄兔肉(p0.05)。     

欧姆加热对肉品质影响的研究进展

欧姆加热即电加热,是利用原料对电流的抵抗作用,将电能转化为热能,从而达到加热目的。欧姆加热与传统加热相比具有加热速度快、出品率高、加热均匀、颜色好、嫩度高等优点。近年来,欧姆加热在肉制品加工方面的应用成为研究热点。本文综述了欧姆加热对肉及肉制品蒸煮损失、颜色、嫩度、微生物、脂肪氧化和感官等方面的影响,并对该技术在肉品加工领域的应用前景进行了展望。     

EFFECT OF ULTIMATE pH ON THE QUALITY CHARACTERISTICS OF PORK

A study was conducted to characterize the relationship between Longissimus thoracis ultimate pH(LTpH) and pork quality. Animals (n = 47) were selected based on LTpH measured at 24 h postmortem. Data were analyzed using regression procedures with ultimate pH as the independent variable, and relationships were determined to be linear (L), quadratic (Ql or cubic (C). Ultimate pH explained 79% (C) of the variation in subjective color, which increased as pH increased. Drip loss, purge loss and L* value decreased as LTpH increased (R²= 0.57C, 0.77 Q and 0.68 Q, respectively). Shear force decreased and sensory juiciness increased as LTpH increased (R²= 0.26Q and 0.46C, respectively). However, of flavor intensity increased as LTpH fell below pH 5.2 or exceeded 6.1(R²=0.52C). Increasing LTpH, up to a point, will improve fresh pork quality and processed meat properties, whereas, above approximately 6.1, of-flavor may increase.     

EFFECT OF DIFFERENT COATING TREATMENTS ON THE QUALITY OF MANGO FRUIT

Eight coating formulations were evaluated for beneficial effects on the shelf‐life of mangoes (cvs. Kent, Tommy Atkins, and Lirfa) harvested at different maturity stages. Four coatings were then selected for further study under various conditions of storage including ambient (19–22C and56–60% RH) and simulated commercial (12C and 80% RH) storage. The four coating formulations contained carnauba wax, shellac, zein, and/or cellulose derivatives. All coatings reduced the respiratory rate, the development of external and internal color, and all but carnauba wax retarded the loss of firmness. Changes in acids were also delayed in all coated mangoes. Based on these parameters, fruit maturation was estimated to have been delayed by a few days compared with uncoated fruit. Shellac and cellulose‐based coatings, however, caused elevated levels of ethanol, although this did not lead to significant flavor differences from the control (uncoated fruit) in sensory tests. Only the carnauba wax coating was an effective water loss barrier under conditions of high RH.     

注射CaCl2对猪半腱肌品质的影响

选用宰后48 h的猪半腱肌,注射占肉重5%、浓度分别为0和300mmol/L的CaCl2溶液,放在4℃左右条件下冷藏72 h后,测定其剪切力、煮熟率、pH和总色素,以此分析CaCl2处理对猪半腱肌品质的影响.结果显示,注射CaCl2能显著降低猪半腱肌的剪切力（P＜0.05）,但对煮熟率、pH和总色素影响均不显著（P＞0.05）.可见,注射CaCl2能通过改善猪半腱肌的嫩度而提高其品质,而对系水力、pH和色泽没有影响.     

谷氨酰胺转氨酶对猪肉糜失水率和硬度影响的研究

研究了谷氨酰胺转氨酶对猪肉糜保水性及对猪肉糜糕弹性的影响。结果表明最佳作用添加量为0.45%、最佳作用温度为35℃、最佳作用时间为2.0h;辅料大豆蛋白GsNa、大豆蛋白EGP和大豆蛋白HTP对谷氨酰胺转氨酶作用影响结果表明添加4%的大豆蛋白GsNa和添加0.1%的大豆蛋白EGP能显著改善猪肉糜的保水性及猪肉糜糕的弹性,而大豆蛋白HTP对其影响则不明显。     

THE INFLUENCE OF COOKING METHOD ON THE QUALITY OF PORK PATTIES

Pork patties were subjected to traditional frying, cooking in a microwave oven (microwaves  +  grill), hot air cooking in a cyclojet (Electrim JI-9101 RP, Taiwan) and cooking in a steam-convection (combi) oven (hot air  +  30% steam) (BECK FCV 4 EDS, BECK GmbH, Jagsthausen, Germany). Products cooked in the combi oven (BECK FCV 4 EDS) were characterized by the smallest cooking loss, the highest retention of water and the lowest content of fat compared to other samples. The content of hydroxymethylfurfural in fried and cyclojet-cooked patties was almost twofold higher than in microwave and combi oven-cooked samples. The intensity of lipid oxidation was also higher in fried and cyclojet-cooked meat than in the other two products. The intensity of meat flavor was the strongest in the combi oven-cooked patties. All products were characterized by a low intensity of fatty flavor. The highest scores for overall acceptability were given to the combi oven-cooked patties, whereas the lowest scores were given by the panelists to the microwave-cooked patties.

PRACTICAL APPLICATIONS

Pork patties are an important meat product both in catering production for direct consumption and in convenience food industry when intended for refrigerated or frozen storage. As cooking is a main stage in preparation of patties for consumption, it is essential to use a method of cooking that ensures the high nutritional and sensory quality of products. Most often, pork patties are subjected to deep frying or traditional frying; however, several other cooking methods can be used. The present work shows that the combi oven cooking enables production of patties of desirable nutritional and sensory characteristics and low content of unfavorable compounds.