Alcalase酶解对淘汰蛋鸡风干成熟过程中蛋白质分解变化规律的影响

以淘汰蛋鸡为原料,腌制后采用碱性蛋白酶（Alcalase）酶解并风干成熟,分别分析酶解组与对照组加工过程中蛋白质的分解及游离氨基酸的变化,确定蛋白质分解变化的规律。结果表明：Alcalase能显著促进淘汰蛋鸡蛋白质的水解,Alcalase酶解鸡肉蛋白后能显著增加鸡肉肌纤维小片化指数以及蛋白质水解指数（P＜0.05）,与对照组相比,鸡肉中肌浆蛋白和肌原纤维蛋白在腌制结束后有显著的分解（P＜0.05）,分子质量大于72 kD的蛋白质逐渐分解,小于28 kD的小分子蛋白逐渐累积;对产品游离氨基酸的分析结果表明,通过Alcalase酶解能显著增加成品中的游离氨基酸总量,与对照组相比,在风干后期有更多的氨基酸参与后续的分解反应,说明Alcalase对风干成熟后期游离氨基酸进一步转化为风味物质也有促进作用。     

鸡蛋松花蛋腌制中蛋白质凝胶特性及颜色变化

以新鲜鸡蛋为原料,采用现代“锌法”腌制工艺加工鸡蛋松花蛋,并分析松花蛋内蛋白质凝胶变性、色差等随腌制时间的变化。结果表明：在腌制过程中,松花蛋内游离碱度、硬度、弹性、咀嚼性等显著上升,蛋白质凝胶能力逐渐降低（P＜0.05）,在腌制28 d后变化趋势逐渐稳定（P＞0.05）;松花蛋在腌制过程中蛋白质分解主要表现在腌制0～14 d,大于86.6 kD的蛋白质逐渐分解;随着松花蛋内碱度的增加,小分子肽类物质（14.3、10 kD）不断累积,蛋清及蛋黄内游离氨基酸含量显著降低（P＜0.05）,在腌制21～28 d后无明显的变化;腌制时间对鸡蛋松花蛋颜色变化有重要的影响,蛋清及蛋黄颜色变化与腌制时间、游离碱度及游离氨基酸含量成显著负相关;主要表现为在腌制过程中L*、b*值变化趋势与a*值变化趋势相反,蛋清及蛋黄整体颜色变化（白度值）趋势成负相关。     

Alcalase协同强化高温风干成熟工艺对狼山鸡蛋白质水解的影响

以南通狼山鸡为原料,采用碱性蛋白酶（Alcalase）酶解结合强化高温风干成熟工艺制作风鸡,以游离氨 基酸总量（ΣFAA）、蛋白质水解指数为响应指标,采用响应曲面试验方法分析Alcalase协同强化高温风干成熟工 艺对狼山鸡蛋白质水解的影响,并优化狼山鸡强化高温风干成熟工艺。结果表明：Alcalase能显著促进原料的蛋白 质水解,鸡肉中ΣFAA随着Alcalase添加量与强化高温温度提高而显著提高;Alcalase添加量与强化高温温度和风 干温度对ΣFAA有显著的交互作用（P＜0.05）;在控制蛋白质水解指数小于11%的前提下,得到Alcalase酶解风干 狼山鸡的优化工艺为强化高温温度46 ℃、酶添加量1.88 U/g、风干成熟起始温度14.5 ℃,风干狼山鸡的ΣFAA为 2.02 g/100 g,蛋白质水解指数为10.42%。说明Alcalase酶解协同强化高温风干成熟工艺能有效促进狼山鸡蛋白质水 解,提高风味品质。     

狼山鸡风干成熟工艺优化

以南通市狼山鸡为原料,通过Box-Behnken试验设计其风干成熟工艺,研究不同风干起始温度、风干时间、腌制用盐量与风干狼山鸡感官品质及蛋白质水解之间的关系.结果表明:风干起始温度、风干时间与蛋白质水解及感官品质之间呈显著正相关(P＜0.05);以风干狼山鸡的总体感官评分最大值为目标值进行回归优化分析,所得结果为风干起始温度12.5℃、风干时间93h、腌制用盐量2.6％,此时产品感官评分为92分,游离氨基酸总量(∑FAA)为1.54mg/100g,蛋白质水解指数(PI)为10.33％,水分含量为58.42％,剪切力为3.62kg/cm2,盐分为3.87％.     

萨拉米香肠发酵成熟过程中蛋白质水解及脂质氧化规律

研究萨拉米香肠从加工到发酵阶段的蛋白质及脂质水解氧化规律。结果显示,在萨拉米香肠发酵成熟过程中,蛋白质水解指数不断增加,并且在高温发酵初始及发酵15 d阶段是蛋白质水解和游离氨基酸总量累计的主要阶段。发酵45 d,游离氨基酸总量略降低但与发酵中期总量差异不显著。另外,中性脂质及游离脂肪酸相对含量显著增加（P＜0.05）,而磷脂相对含量不断降低;除油酸和鳕油酸外的不饱和脂肪酸含量在发酵成熟过程中均呈现先升高后降低的趋势,并且该趋势与脂质氧化的变化趋势相同。因此,萨拉米香肠发酵成熟过程中脂质水解及氧化的发生是同步的。     

腌制风干过程中卵形鲳鲹鱼肉性质、蛋白质氧化及游离氨基酸的变化

为探究卵形鲳鲹在腌制风干过程中蛋白质氧化及游离氨基酸的变化规律,对卵形鲳鲹鱼肉含水率、盐含量、质构特性、肌原纤维蛋白二级结构、羰基含量、巯基含量、蛋白质水解指数、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳图谱和游离氨基酸等进行测定分析。结果表明：在腌制风干过程中,卵形鲳鲹鱼肉的盐含量整体呈上升趋势,含水率下降,硬度增加,而弹性则先上升后下降。鱼肉蛋白质在加工过程中发生氧化反应,羰基含量明显增加,而巯基含量明显下降,同时肌原纤维蛋白二级结构中α-螺旋含量减少,而无规卷曲含量增加。在加工过程中肌球蛋白重链条带和肌动蛋白发生明显变化,肌球蛋白重链条带变浅并在风干后消失,表明肌原纤维蛋白发生水解;鱼肉的蛋白质水解指数增加,非蛋白氮含量在腌制后下降而在风干过程中增加;游离氨基酸总量在干制1 d后达到最高,鲜味氨基酸和苦味氨基酸含量整体呈上升趋势。本研究可为腌制水产品加工过程中品质控制提供一定理论参考。     

姜辣素对培根风干成熟过程中微生物及生物胺形成的抑制效应

以五花肉为原料,腌制时添加不同含量（100、300、500 mg/kg）的姜辣素进行风干成熟,测定样品理化指标、微生物及生物胺含量变化情况,研究姜辣素对培根风干成熟过程中微生物及生物胺形成的抑制效应。结果表明：与对照组相比,姜辣素能显著抑制菌落总数和肠杆菌（P＜0.05）;在风干培根样品中共检测到腐胺、尸胺、组胺、酪胺、精胺5 种生物胺;生物胺总量随着风干时间的延长呈显著增加趋势（P＜0.05）,100、300、500 mg/kg处理组与对照组总生物胺含量存在显著性差异（P＜0.05）。300 mg/kg处理组总生物胺含量最低,为94.13 mg/kg,相对于对照组降低了34.56%,且此时腐胺、尸胺、酪胺、组胺和精胺含量也得到了很好的抑制,相对于对照组分别下降了26.60%、40.59%、37.08%、72.19%和23.59%。添加姜辣素能显著降低样品中挥发性盐基氮含量（P＜0.05）,对于提高培根的品质及安全性具有较好的效果。     

贵州三穗特色黄皮蛋加工过程中凝胶形成及颜色变化分析

为研究三穗特色黄皮蛋加工过程中凝胶形成及颜色变化机理,以黄皮蛋无铅腌制工艺为基础,测定并分析黄皮蛋加工过程中蛋清游离碱度、微观结构、蛋白质二级结构及分子间作用力、质构特性、色差、还原糖含量、游离氨基酸的动态变化情况。结果表明,腌制过程中（0～18 d）,蛋清游离碱度不断升高,离子键作用力先升高后降低,氢键作用力、疏水作用力、二硫键作用力则逐渐增加;蛋白从粗毛孔无序状态变为有序的三维网状纤维结构;在第12天时,凝胶质构特性各指标总体最高,β-折叠和β-转角为主要结构。腌制12～18 d,高碱度导致凝胶结构被破坏,网孔变大,离子键作用力及质构特性指标水平呈下降趋势。腌制结束（18 d）后,蛋清游离碱度逐渐下降后趋于稳定,质构特性指标水平整体先上升后趋于稳定,凝胶结构自我修复,网孔紧密,凝胶结构稳定。维持凝胶结构的主要作用力为离子键和二硫键,蛋白质二级结构主要为β-折叠和β-转角。在色泽形成过程中,羰氨反应与蛋白质分解同时进行,蛋清还原糖含量降低,总游离氨基酸含量先降低后升高,蛋清红绿度（a值）和黄蓝度（b值）逐渐升高,颜色逐渐变黄变暗。腌制结束后,蛋清各色泽均无明显变化,形成稳定的金黄色。综上可知,黄皮蛋腌制阶段的6～12 d是控制品质的关键阶段,腌制结束后常温放置6 d,蛋清凝胶性质略微提升,色泽稳定,产品品质更佳。     

发酵对山黑猪肉干品质特性的影响

为探究发酵条件对山黑猪肉干发酵过程中理化性质和感官品质的影响,以山黑猪后臀肉为原料,考察发酵温度、接种量和菌种配比3?个因素对山黑猪肉发酵过程中pH值、水分活度（aw）、总游离氨基酸、组胺、亚硝酸盐残留量、蛋白质分子质量、色泽、质构和感官评分的影响。结果表明,不同菌种配比组中,随着木糖葡萄球菌占比增大,游离氨基酸含量、L*、a*逐渐升高（P＜0.05）;随着清酒乳杆菌清酒亚种占比增大,pH值、aw降低,硬度和咀嚼性增大（P＜0.05）;发酵32?h,随接种量增大,组胺含量上升趋势减缓,亚硝酸盐残留量、弹性降低（P＜0.05）,硬度、咀嚼性、a*逐渐增大（P＜0.05）,107?CFU/g组感官评价最佳;发酵32?h,随发酵温度升高,pH值、aw、亚硝酸残留量呈先降低后升高的趋势,游离氨基酸、硬度、咀嚼性、L*和a*显示先增大后减小的趋势。因此,选择合适的发酵条件可以改善发酵山黑猪肉干色泽和质构,提高游离氨基酸含量,降低亚硝酸盐残留量,提高产品安全性。     

不同风干温度对风干草鱼品质特性的影响

研究2种风干温度对风干草鱼理化性质与食用品质的影响。以草鱼为原料,在5～6℃、20 mg/100g盐含量下腌制,然后分别在2种温度下风干,研究常温（22～25℃）风干与低温（6～10℃）风干对风干草鱼加工过程中鱼肉水分含量、盐含量、总挥发性盐基氮（total volatile base nitrogen,TVB-N）含量、pH值、硫代巴比妥酸反应物质（thiobarbituric acid reactive substances,TBARs）值和感官品质的影响。结果表明：在2种风干温度下,风干草鱼的水分含量呈下降趋势,盐含量、蛋白水解指数、TVB-N含量和TBARs值均呈上升趋势;常温风干草鱼的TVB-N含量与TBARs值在风干结束后明显高于低温风干草鱼,其最终TVB-N含量与TBARs值分别为35.61、2.46 mg/100g;低温风干草鱼的TVB-N含量与TBARs值在风干过程中无明显变化;2种风干草鱼pH值在风干过程中均呈上升趋势;低温风干草鱼的感官品质优于常温风干草鱼;除水分含量和TBARs值外,常温风干草鱼感官评分与其他理化指标均呈极显著负相关（P＜0.01）;低温风干草鱼感官评分与TVB-N含量、总氮含量、非蛋白氮含量呈显著正相关（P＜0.05）,与TBARs值、蛋白水解指数呈极显著正相关（P＜0.01）。     

Alcalase酶解狼山鸡肉蛋白规律

以狼山鸡为实验材料,分析Alcalase酶解鸡肉蛋白规律。结果表明：酶解鸡肉蛋白的最适酶解温度为45 ℃、酶添加量为2.0 U/g、酶解时间为4 h;酶解过程中肌浆蛋白和肌原纤维蛋白有较多的氨基酸释放,并且可溶性氮也有大量的累积,酶解产物的分子质量主要集中在30～50 kD之间;在酶解产物中含量最高的氨基酸分别为天冬氨酸和谷氨酸,并且在酶解产物中亲水性氨基酸（hydrophilic amino acid,HLAA）与疏水性氨基酸（hydrophobicamino acid,HBAA）比值在1.41～1.52之间;通过对酶解产物游离氨基酸营养价值的分析,在不同酶解时间的酶解产物中含有丰富的必需氨基酸,该必需氨基酸指数与联合国粮食及农业组织/世界卫生组织（Food AgricultureOrganization/World Health Organization,FAO/WHO）推荐的成人理想氨基酸模式相类似。     

风干肠加工和贮藏过程中蛋白质的降解规律

以总氮、非蛋白氮、氨基酸态氮、挥发性盐基氮、游离氨基酸以及不同种类蛋白质（肌浆蛋白、肌原纤维蛋白、碱溶蛋白和碱不溶蛋白）为指标,分析研究风干肠加工和贮藏过程中蛋白质的降解规律。结果表明：风干肠加工和贮藏过程中总氮含量没有显著变化;非蛋白氮含量持续升高,从原料肉的469.4 mg/100 g增加到成品肠的786.4 mg/100 g,贮藏240 d后增加至1 256.1 mg/100 g;多肽氮和氨基酸态氮含量在加工和贮藏过程中均持续增加,挥发性盐基氮含量在风干过程中没有显著变化,在贮藏180 d后迅速增加;大部分游离氨基酸含量经过加工和贮藏均有所提高,只有半胱氨酸含量明显降低;在加工过程中,肌浆蛋白和肌原纤维蛋白含量均因降解而减少,基质蛋白含量明显增加;在贮藏过程中,肌浆蛋白含量持续降低,肌原纤维蛋白含量在贮藏前180 d无明显变化,贮藏至240 d明显减少,基质蛋白含量没有显著变化。     

Characterization of proteolysis during the ripening of semi-dry fermented sausages

The respective contribution of indigenous enzymes and enzymes from starter bacteria to proteolysis in fermented sausages were determined by comparing the proteolytic changes occurring in sausages resulting from the presence of a proteolytic strain of Staphylococcus carnosus, i.e. S. carnosus MC 1 to the proteolytic changes occurring in control sausages containing glucono-δ-lactone (GDL) and an antibiotic mixture. Proteolysis was quantified by assaying for non-protein nitrogen (NPN) and free amino acids. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and reversed phase high performance liquid chromatography (RP-HPLC) were used to qualitatively assess the proteolytic changes in the sarcoplasmic and myofibrillar proteins as ripening progressed. The concentration of NPN and free amino acids increased in both sausages initially, but subsequently decreased towards the end of ripening in sausages inoculated with the starter culture. SDS-PAGE showed a similar pattern of proteolysis of sarcoplasmic proteins in both sausages, while of the two sausage types; the S. carnosus MC 1 inoculated sausages exhibited the most intense degradation of myofibrillar proteins, especially myosin and actin. RP-HPLC profiles of 2% trichloroacetic acid (TCA)-soluble peptides for the two sausage types were similar, with the production of numerous hydrophilic peptides. N-Terminal amino acid sequence analysis and sequence homology with proteins of known primary structure showed that six of the TCA-soluble peptides were released from the sarcoplasmic (myoglobin and creatine kinase) and myofibrillar (troponin-I, troponin-T and myosin light chain-2) proteins. In addition, the initial degradation of sarcoplasmic proteins was due to the activity of indigenous proteinases, while both indigenous and bacterial enzymes contributed to the initial degradation of myofibrillar proteins. Furthermore, indigenous enzymes were responsible for the release of TCA-soluble peptides, which, were further hydrolysed by bacterial enzymes.     

冰温和冷鲜贮藏对鸡肉肌原纤维蛋白凝胶性能和水分状态的影响

以鸡胸肉为原料,研究4℃冷鲜和-0.7℃冰温贮藏期间鸡肉肌原纤维蛋白凝胶强度、保水性和水分分布状态变化。采用动态流变仪测定其凝胶强度,用离心法测定凝胶的保水性,用低场核磁共振分析凝胶的水分状态变化情况。结果表明:随着贮藏时间的延长,冷鲜和冰温组鸡胸肉肌原纤维蛋白凝胶强度和保水性均呈下降趋势,冰温组蛋白凝胶强度和保水性显著高于冷鲜组(P0.05);低场核磁共振分析表明持水性的下降与不易流动水比例降低和自由水比例提高有关;冰温组蛋白凝胶不易流动水下降和自由水的上升幅度显著低于冷鲜组(P0.05)。冰温贮藏可以更好地保持肌原纤维蛋白的热诱导凝胶性能,从而保证鸡肉的加工品质。     

Contribution of a selected fungal population to proteolysis on dry-cured ham

The proteolytic changes taking place in dry-cured hams lead to increases in free amino acids. Such free amino acids not only contribute to flavour, but also serve as precursors of volatile compounds. Several months of ripening time are required to allow the particular flavour to develop. The fungal population allowed to grow on the surface of some types of dry-cured could play a key role on proteolysis, as it has been shown for dry-cured sausages. The purpose of this work was to study the possible contribution of fungi to proteolysis in dry-cured ham. For this, a strain each of non-toxigenic Penicillium chrysogenum (Pg222) and Debaryomyces hansenii (Dh345), selected for their proteolytic activity on myofibrillar proteins, were inoculated as starter cultures. Changes in the high ionic strength-soluble proteins of an external muscle (adductor) revealed in only 6 months higher proteolysis in the inoculated hams when compared to non-inoculated control hams. Proteolytic strains among the wild fungal population on non-inoculated control hams prevented from obtaining similar differences at the end of processing. However, inoculation with Pg222 and Dh345 led to higher levels for most free amino acids at the external muscle in fully dry-cured hams. In addition, the concentration for some of the more polar free amino acids (i.e. Asp, Glu, Ser and Gln) in inoculated hams was higher at external than at internal (biceps femoris) muscles. These promising results deserve further studies to know the impact of a selected fungal population on the volatile compounds and sensory properties of dry-cured ham.     

Proteolysis,physicochemical characteristics and free fatty acid composition of dry sausages made with deer (Cervus elaphus) or wild boar (Sus scrofa) meat: A preliminary study

In order to contribute to typifying delicatessen made with game meat, the proteolysis, physicochemical characteristic and free fatty acid composition were determined in 10 commercial dry sausages, chorizos and saucissons, made with deer or wild boar meat. The a_w and pH values were similar for all the samples; however, the results for dry matter, protein nitrogen, fat, ash, sodium chloride, phosphorus, and sodium nitrite content showed great variation among the samples tested. The myofibrillar protein content was higher than the sarcoplasmic protein content in all samples analysed. The electrophoretic profiles of sarcoplasmic and myofibrillar proteins were different among samples. Principal components analysis, run on the relative density of myofibrillar and sarcoplasmic proteins, separated the chorizo and saucisson samples. Chorizo samples were a homogeneous group in the analysis of myofibrillar proteins, which indicated similar proteolysis effects for all samples. The majority acids were oleic, palmitic, linoleic and stearic in all samples. Chorizos differed from saucissons in the greater quantity (P < 0.05) of polyunsaturated fatty acids.     

乳酸菌发酵对草鱼肉理化特性和蛋白质降解变化的影响

研究了乳酸片球菌、乳杆菌-Lo3、乳杆菌-B5407和清酒乳杆菌4种不同乳酸菌在发酵草鱼肉时鱼肉理化特性及蛋白质降解变化的规律和特征。结果表明:添加乳酸菌后,鱼肉pH值迅速由最初的6.25降至2d时的5.06～5.40,对照组则为5.98;接种发酵剂的草鱼肉的TBA和TVB-N值的上升较缓慢,整个发酵过程中显著低于对照组(P<0.05);腌制草鱼肉的蛋白质在发酵期发生了轻微的降解,游离氨基酸略有增加;贮藏期间游离氨基酸量显著增加,肌浆蛋白和肌原纤维蛋白均发生了强烈的水解,接菌组的蛋白降解显著多于对照组,其中,接种乳酸片球菌和乳杆菌-B5407组降解程度最大。     

Proteolytic activity of Penicillium chrysogenum and Debaryomyces hansenii during controlled ripening of pork loins

The role of micro-organisms on the ripening process of dry-cured ham, particularly with respect to proteolysis, is not clear. This is partially due to the lack of an adequate system to study changes on a sterile control meat product for long ripening times. Using a meat system based on sterile pork loins ripened under aseptic conditions for 106 days, the contribution to the proteolysis of two micro-organisms isolated from dry-cured ham has been established. Changes were studied by SDS-PAGE of sarcoplasmic and myofibrillar proteins, capillary zone electrophoresis (CZE) of low ionic strength-soluble nitrogen compounds, and HPLC of free amino acids. Debaryomyces hansenii Dh345 did not show any significant proteolytic activity. However, Penicillium chrysogenum Pg222 showed high proteolytic activity on myofibrillar proteins resulting in an increase in soluble nitrogen compounds. For this, P. chrysogenum Pg222 should be considered to be used as starter culture in meat products made using long ripening times.     

内蒙古地区不同养殖草食动物背最长肌氨基酸组成及营养价值评价

以内蒙古地区集约化养殖草食动物牛、绵羊、山羊和驴背最长肌为研究对象,以鸡胸肉为参照,采用全自动氨基酸分析仪内标法检测氨基酸含量,评价肌肉氨基酸组成及营养价值。结果表明：各氨基酸在不同动物肌肉中的含量均呈显著差异（P＜0.05）;鸡胸肉、牛肉和山羊肉总必需氨基酸含量显著高于绵羊肉（P＜0.05）,驴肉与其他肉无显著差异;牛肉和驴肉总非必需氨基酸含量显著高于山羊肉（P＜0.05）,其他肉无显著差异。不同草食动物肌肉必需氨基酸指数（essential amino acid index,EAAI）均高于95,属于优质蛋白质来源,EAAI顺序为山羊肉＞鸡胸肉＞绵羊肉＞牛肉＞驴肉;驴肉甜味氨基酸含量显著高于其他肉（P＜0.05）,牛肉和绵羊肉鲜味氨基酸含量显著高于其他肉（P＜0.05）,鸡胸肉苦味氨基酸含量显著高于其他肉（P＜0.05）,牛肉和绵羊肉总呈味氨基酸含量显著高于其他肉（P＜0.05）;以氨基酸相对含量聚类,绵羊肉和牛肉在图谱中最接近,驴肉处于图谱最远端。