华北野猪与家猪杂交后的品质评定

应用感官评定、仪器测定和模糊数学评定的方法,研究杂种野猪的肌肉品质特性,通过与当地白猪比较分析,较全面地评定杂种野猪肉的感官品质、营养品质和加工品质。结果显示,成熟后的杂种野猪肉色泽为3.6,接近于色泽的标准值3.5;其肉质的大理石花纹不丰富;将嫩度、风味和多汁性分别赋予0.4、0.4、0.2的加权值,应用模糊数学的方法对其肉质做出了客观评价,评定结果为良好,杂种野猪肉优于当地白猪肉;杂种野猪肉蛋白质含量较高;脂肪含量较低;成熟后的pH值较高;蒸煮损失率和滴水损失率均较低。     

杂种野猪宰后肌肉品质特性的研究

品种是影响猪肉食用品质的最主要因素,而猪肉的化学组成成分和宰后生理生化变化则是肌肉品质形成的基础.本文针对杂种野猪和本地白猪两种不同的品种猪,在相同条件下饲养和屠宰,研究了宰后肌肉的色泽红度a值、pH值、嫩度(剪切力)和蒸煮损失的变化情况.试验表明:杂种野猪达到极限pH的时间比本地白猪的长,杂种野猪的嫩度比本地白猪差,但蒸煮损失率却比本地白猪肉低.     

关于特种野猪和长白山野猪肉发展的几点思考

随着人们消费水平的提高,生活质量也在不断提高,对猪肉的消费也提出了越来越高的要求。野猪肉与家猪相比,具有更好的食用品质,其肉色泽鲜艳、风味独特、营养丰富、具有良好加工性能和耐贮藏性,是一种典型的能够满足现代人们消费需求的具有野味的高蛋白低脂肪的肉类食品。本文主要结合长白山野猪的特点和特种野猪的发展,对长白山野猪肉品质发展提出几点思考。     

猪肉中有害微生物的研究进展

近年来,猪肉品质和安全性问题已经成为人们的关注热点之一.本文主要探讨了猪肉中的有害微生物这一影响猪肉品质和安全性的生物学因素,同时全面研究了猪肉中的病原菌和腐败菌等有害微生物的来源、种类、特性等,为今后能进一步研发出有效监测猪肉品质、保障肉品安全性的新型模型和检测方法提供了重要的借鉴与参考.     

不同解冻方式对猪肉品质特性的影响

研究自然空气解冻、静水解冻、微波解冻和低温解冻4 种不同解冻方式对猪背最长肌肉品质特性的影响,分析猪肉解冻过程中食用品质特性、全质构特性、肌浆蛋白和全蛋白含量的变化。结果表明：冻结猪肉经静水解冻后,肌肉pH值接近6.0,解冻损失率和蒸煮损失率较低,静水解冻使猪肉的保水性维持较好。冻结猪肉解冻过程中肌浆蛋白和肌肉全蛋白浓度的变化对肉质构特性有显著或极显著影响。微波解冻有利于保持猪肉的嫩度和色泽,且通过微波解冻的冷冻猪肉其肌肉全蛋白含量较高,肉品的全质构特性较好。4 种解冻方法中,静水解冻和微波解冻能较好地保持解冻猪肉的品质。     

宰前管理和屠宰工艺对宰后猪肉品质的影响

猪肉品质是人们对猪肉多种质量特性的综合评价。影响猪肉品质的因素诸多,本文主要从生猪宰前管理、屠宰工艺、宰后处理等环节进行分析,综述了近年来国内外学者研究成果,从而为猪肉生产各环节及关键点进行有效控制,降低PSE肉发生率及生产出安全、优质的猪肉产品相关科学研究提供理论依据。     

不同种类淀粉对上浆猪肉片品质的影响

为研究不同种类淀粉对上浆猪肉片品质的影响,采用小麦淀粉、玉米淀粉和马铃薯淀粉对排酸成熟24 h的猪肉片进行上浆处理,未上浆猪肉片为空白对照,测定滑油后猪肉片的烹饪损失率、质构特性、色泽、水分含量、蛋白质含量、脂肪含量并观察其微观结构,同时利用模糊数学综合评价法分析其感官品质。结果表明,上浆猪肉片滑油后的烹饪损失率明显低于空白对照组,且马铃薯淀粉上浆猪肉片烹饪损失率最低,仅为4.83%。在质构特性和营养成分上,上浆猪肉片与未上浆猪肉片滑油后差异显著(P<0.05),马铃薯淀粉上浆猪肉片硬度值最小,弹性最大,水分含量最高,达67.91%。微观结构显示了马铃薯淀粉上浆猪肉片滑油后肌纤维结构更为松散,嫩度最好,与质构特性结果相符。模糊感官综合评分最高的是马铃薯淀粉上浆猪肉片,为81.45分。综合指标显示马铃薯淀粉更适于猪肉片上浆预制品加工。     

猪PSE肉的预防和改进措施

全球肉类加工业对PSE猪肉的关注与日俱增,这类劣质肉具有较高的亮度值和较差的保水性,同时加工产品的品质显著下降。叙述了猪PSE肉预防措施和加工特性的相关改进措施。为冷鲜猪肉的生产、品质的改善提供理论依据和技术支持。     

快速与慢速解冻对冷冻猪肉品质特性及蛋白变性的影响

研究快速解冻技术(微波、超声)与慢速解冻技术(流水、空气、低温、35℃静水)对猪肉品质特性及蛋白质变性程度的影响,以新鲜猪肉作为对照组,分析六种解冻方式对冷冻肉,解冻速率、保水性、色泽、脂肪氧化程度(TBARS)、蛋白溶解性、蛋白变性程度、新鲜度及剪切力值的影响。结果表明,与新鲜猪肉相比,经解冻处理后,猪肉的品质特性均有不同程度的变化;经差示热量扫描仪(DSC)热分析也可看出,解冻方式对猪肉蛋白质的变性程度有一定影响。六种解冻方式中,微波解冻作为一种快速解冻方式,耗时最短,解冻速率为39.61 cm/h,与慢速解冻相比,大大提高了解冻效率(p<0.05),且能较好地保持猪肉的保水性和嫩度,解冻后猪肉的TBARS值和蛋白变性程度较低,新鲜度也仍在一级鲜肉的水平。由此说明,微波解冻能较好地保持猪肉的品质。     

乙酸钠协同桂皮提取液对微冻猪肉保鲜效果的影响

为延长猪肉货架期,提高其食用安全品质,将新鲜猪肉分别用2%乙酸钠和2%乙酸钠+5.6%桂皮提取液(均为质量分数)浸渍后托盘包装,于-3℃的冷库中微冻贮存,考察保鲜剂对微冻猪肉感官品质、微生物品质和理化品质的影响。结果表明:猪肉经2%乙酸钠浸渍后可以延缓微生物的生长繁殖,抑制蛋白质分解和脂肪氧化,较好地维持猪肉的品质特性,而乙酸钠与桂皮提取液协同作用的保鲜效果更佳。通过理化、微生物及感官品质指标的综合评价,2种处理均能够在一定时间内较好地保持猪肉的新鲜度,延缓腐败变质的发生,猪肉样品的货架期分别为2%乙酸钠处理组28 d、乙酸钠+桂皮提取液处理组36 d(无菌蒸馏水处理的空白组小于20 d)。     

Comparative study of the histochemical properties, collagen content and architecture of the skeletal muscles of wild boar crossbred pigs and commercial hybrid pigs

The histochemical properties, collagen content and architecture of Musculus longissimusthoracis (LT), Musculus pectoralis profundus (PP) and Musculus biceps femoris (BF) were compared in F(1) (half blood) and F(2) (quarter blood) wild boar crossbred pigs and commercial hybrid pigs, and Japanese wild pigs. F(1) pigs showed the lowest growth rate, followed by F(2) pigs. The most rapid growth was shown by the commercial pigs. The percentage weights of LT and PP muscle to body weight were larger in the wild boar crossbred pigs than commercial pigs. The muscles of the crossbred pigs contained type I and IIA myofibers at higher frequency and type IIB at lower frequency than the commercial pigs, except for LT muscle of F(2) pigs. The myofiber diameter in each type of muscle did not differ between pigs except for the smaller type IIA in BF muscle in commercial pigs. The total amount of intramuscular collagen was less in LT muscles than the others. More intramuscular collagen was found in the wild boar crossbred pigs than the commercial pigs in LT and PP muscles. With an increase of collagen content, the perimysial collagen architecture developed but not the endomysial architecture. Traits characteristic of the crossbred pigs seem to be inherited from the wild boar. Our results clarify that cross breeding with wild boar results in pigs with distinctive muscle characteristics in terms of histochemical properties, collagen content and architecture.     

两种杂交商品猪冷却肉常规养分含量、蛋白质溶解性及脂肪酸组成的比较

通过比较含地方猪血缘的杂交商品猪(杜浙猪)与外三元杂交商品猪(杜大长)背最长肌和腰大肌冷却肉的常规养分、蛋白质溶解度及脂肪酸组成,深入评价含地方猪血缘的杂交商品猪在优质猪肉生产中的优势。结果表明,杜浙猪背最长肌冷却肉的粗蛋白和粗脂肪含量显著高于杜大长猪(p<0.05),粗灰分含量显著低于杜大长猪(p<0.05);杜浙猪背最长肌和腰大肌冷却肉的肌浆蛋白溶解度均显著高于杜大长猪(p<0.05),纤维蛋白溶解度显著低于杜大长猪(p<0.05);杜浙猪背最长肌和腰大肌冷却肉的饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸含量均显著高于杜大长猪(p<0.05)。综合上述指标,杜浙猪冷却肉的营养价值和蛋白质功能性优于杜大长猪,将为充分利用地方猪种资源进行优质猪肉生产提供依据。     

3 种猪肉的品质分析

以恩施当地传统饲养黑内二元猪、全价配合饲料饲养黑内二元猪及全价配合饲料饲养三元猪为样本,分别测定3 种猪后腿肉和里脊肉的矿物质含量、质构、风味成分,以探讨不同品种及饲喂方式对猪肉品质的影响。结果表明：传统饲养黑内二元猪肉Se含量最高,且肉硬度最大;全价配合饲料饲养黑内二元猪肉的嫩度最大;3 个类型猪的生肉和熟肉均存在风味差异,可通过电子鼻进行区分。     

梅山猪与三元杂交猪肉宰后成熟过程品质变化比较

目的：比较梅山猪与三元杂交猪的肉品质以及影响两个猪种持水力的因素,为梅山猪肉质性状的选择提供一定的参考。方法：选取6 头梅山猪和6 头三元杂交猪,在宰后45 min取胴体左侧背最长肌,采用低场核磁共振技术测定肌肉中水分分布情况以及酪蛋白酶原分析法测定钙蛋白酶的活性,在成熟过程中的1、3、7 d测定肌肉的持水力。结果：梅山猪肉色的L*值和a*值与三元杂交猪差异显著（P＜0.05）。梅山猪宰后成熟1、3 d的贮藏损失率和宰后1 d的蒸煮损失率显著低于三元杂交猪（P＜0.05）,说明梅山猪肉具有较高的保水性。梅山猪宰后45 min的pH值显著高于三元杂交猪（P＜0.05）。低场核磁共振T2弛豫测定结果表明,梅山猪肉中结合水含量显著高于三元杂交猪,自由水含量显著低于三元杂交猪（P＜0.05）。肌肉水分分布的差异在一定程度上解释了两种猪肉的持水力的变化。梅山猪与三元杂交猪肉中的钙蛋白酶活性在成熟第1天差异显著（P＜0.05）,成熟第3天和第7天差异不显著。结论：钙蛋白酶活性对这两个猪种的保水性影响不大,肌肉的水分分布及宰后45 min、pH值的差异解释了梅山猪具有较高的保水性。     

青海八眉猪及其杂交猪肉挥发性成分分析

通过固相微萃取和气相色谱-质谱联用仪对青海八眉原种、二元长八、三元约长八及杜长大（对照）猪肉的挥发性风味成分进行检测分析。结果表明：八眉原种猪肉中挥发性风味化合物种类繁多、成分复杂,相对含量最高,且各风味成分以醛类物质为主;八眉原种、二元长八、三元约长八猪肉中壬醛（清香气味）、癸醛（甜香和柑橘香）、2,4-癸二烯醛（油脂香）、十二醛（皂香、柑橘香）、十四醛（脂肪香）、十六醛（花和蜡的弱香气）等醛类物质较杜长大猪肉丰富;1-辛醇（油脂香味、橘柑和玫瑰香味）、1-辛烯-3-醇（蘑菇香、青香、蔬菜香）、2-庚醇（淡芳香、脂肪香）等醇类物质分别在八眉原种、二元长八、三元约长八猪肉中有不同程度检出,3 组猪肉的醇类物质种类及相对含量也高于杜长大猪肉;同时,十二烷酸（月桂油香）、十四碳酸（微弱的蜡香和乳香）、苯酚类（甜香）等化合物的相互作用叠加使八眉原种猪及其杂交猪肉形成独特风味,与杜长大猪相比肉质细腻、味道鲜美、风味醇香浓郁、肉品质量上乘。     

Differentiation of the raw material of the Iberian pig meat industry based on the use of amplified fragment length polymorphism

The present study is the first step of the development of a new analytical technique to discriminate the genotypes of purebred Iberian and crossbred Iberian×Duroc pigs. A DNA test of breed identity has clear advantages for the protection of the brand name of high-prized products of purebred Iberian pigs. Amplified fragment length polymorphism procedure was used to analyze the genomic DNA samples of 77 Duroc and 80 Iberian pigs from the most representative populations. Thirteen primer combinations produced 588 amplified fragments. A total number of 139 fragments were polymorphic and 14 out of them were detected in Duroc and never in Iberian pigs. A panel of the nine most frequent markers allows the discrimination between purebred and crossbred animals. The values of the probability of exclusion of the pure Iberian origin (P(EC)) were 0.97 and 0.78, for crossbred individuals with 50 or 25% of Duroc genes, respectively.     

Quality traits in muscle biceps femoris and back-fat from purebred Iberian and reciprocal Iberian×Duroc crossbred pigs

The present study evaluated the physico-chemical characteristics of muscle biceps femoris and back-fat from purebred Iberian (PBI) pigs and reciprocal crossbred Iberian × Duroc pigs (IB × D pigs: Iberian dams × Duroc sires; D × IB pigs: Duroc dams × Iberian sires). Muscles from PBI pigs contained significantly higher amounts of IMF, heme pigments and iron than those from crossbred pigs. In addition, muscles from PBI pigs were darker (lower L^*-values) and redder (higher a^*-values) and exhibited a more intense colour (higher chroma value) which was closer to the true red axis (lower hue value) than muscles from crossbred pigs. Back-fat from PBI pigs had significantly higher percentages of monounsaturated fatty acids (MUFA) and significantly smaller percentages of polyunsaturated fatty acids (PUFA) than those from crossbred pigs. Regarding the fatty acid profiles of the muscle lipid fractions, the genetic background particularly affected the composition of the polar lipid (PL) fraction. PL in muscles from PBI pigs contained significantly higher proportions of oleic acid and total MUFA and significantly lower amounts of arachidonic acid, certain long-chain PUFA (ω-6 and ω-3 fatty acids) and total amount of PUFA than PL in muscles from crossbred pigs. The results obtained indicate that tissues from PBI pigs would be more suitable for the production of dry-cured meats than those from cross-bred pigs. The position of the dam or the sire in reciprocal Iberian × Duroc crosses had no clear effects on meat quality.     

Preference and juiciness of Iberian dry-cured loin as affected by intramuscular fat content, crossbreeding and rearing system

Preference ranking tests for juiciness and overall liking of dry cured loins from Iberian pigs with different genetic backgrounds (pure Iberian or crossbred Iberian×Duroc pigs), reared under different productive systems (outdoors on acorns and grass or indoors with mixed diets) and with different intramuscular fat (IMF) content, were conducted. IMF showed a positive influence on preference for juiciness and liking in subjects over 25 years of age, while younger consumers showed a similar trend for juiciness but not for preference. Loins from pure Iberian pigs showed significantly better ranking for juiciness and overall liking than those from crossbred pigs, even when the IMF content was similar. Dry cured loins from pigs reared outdoors and fed on acorns and pasture were ranked significantly better than those from animals fed indoors on concentrates, even though the mixed diets used were enriched in monounsaturated fatty acids and vitamin E in order to obtain meat with similar features to that of pigs reared outdoors, and despite very similar IMF contents. In conclusion, dry cured loins with high IMF content, from pure Iberian pigs and reared outdoors on acorns and grass attain the highest consumer preference.     

Meat quality comparison of Berkshire, Duroc and crossbred pigs sired by Berkshire and Duroc

The object of this study is to specify features determining meat quality of Berkshire and Duroc and influence of these purebreds on meat quality of crossbred pigs. In total, 37 purebred pigs (Berkshire and Duroc: originating from line breeding in Kagoshima Prefecture and Miyagi Prefecture, respectively) and two crossbreeds (LDB and LDD: produced by crossing Berkshire and Duroc boars to Duroc-Landrace sows) were used. Berkshire accumulated more subcutaneous and abdominal fat and had small loin eye muscle area, but accumulated less intramuscular fat than Duroc. There were no differences in meat colour and tenderness between the two purebreds. But Berkshire was less than Duroc in drip loss. As for fatty acid of inner and outer subcutaneous fat, Berkshire contained significantly higher concentration of saturated fatty acids, but had lower concentration of unsaturated fatty acid than Duroc. As a result, the melting point of inner and outer subcutaneous fat and perirenal fat of Berkshire was significantly higher than that of Duroc. Furthermore, though there was no breed difference in concentration of saturated fatty acids of intramuscular fat, Duroc had more oleic acid (C18:1) than Berkshire. Fatty acid concentrations of inner and outer subcutaneous fat and intramuscular fat as well as melting points of both subcutaneous fat layers and perirenal fat were the same in Berkshire and LDB and in Duroc and LDD. These results suggest that there were remarkable differences between Berkshire and Duroc in fat quality traits; also, both breeds as terminal sires influenced crossbred pigs' fat accumulation and fat quality traits.