基于电子舌和色谱技术分析蒸煮猪肉滋味物质

将3种原料猪肉(藏香猪、三门峡黑猪、杜长大白猪)分别蒸煮后,利用液相色谱分别测定游离氨基酸和呈味核苷酸、气相色谱测定脂肪酸含量,电子舌检测样品滋味物质,采用SPSS 19分析3种猪肉滋味的差异。结果表明:蒸煮后三门峡黑猪肉的游离谷氨酸含量最高,藏香猪肉的肌苷酸含量最高,二者的鲜味较强。蒸煮后藏香猪肉5′-腺嘌呤核糖核苷酸(5′-AMP)和5′-次黄嘌呤核苷酸(5′-IMP)含量最高,达192.41mg/100g,三门峡黑猪次之,杜长大白猪最小,藏香猪鲜味增强作用较强。蒸煮后,三门峡黑猪总脂肪酸含量最高为(2.25±0.02)mg/g,三门峡黑猪饱和脂肪酸含量最高,其次为藏香猪,杜长大白猪含量最低。蒸煮后3种猪肉的第1主成分贡献率值距离较近,表明蒸煮后3种猪滋味具有相似性。蒸煮后藏香猪、三门峡黑猪和杜长大白猪肉鲜味物质差异较大,滋味相似。     

基于电子舌和电子鼻结合氨基酸分析鱼香肉丝调料风味的差异

为实现快速、准确地鉴别鱼香肉丝调料的整体风味信息,本实验以市售不同品牌的鱼香肉丝调料为研究对象,采用电子鼻和电子舌分析不同品牌调料的气味和滋味差异性,并结合氨基酸分析,解析游离氨基酸与电子舌滋味特性之间的相关性。结果表明:电子鼻能够准确区分不同品牌鱼香肉丝调料的气味,样品B和C的香气相似,其它样品的香气差异明显。电子舌对于不同品牌鱼香肉丝调料的滋味区分较好,样品D的酸味较为突出,样品A的甜味较为突出,样品E在咸味和鲜味较为突出。在样品E中,谷氨酸、丙氨酸、丝氨酸、缬氨酸、苯丙氨酸和组氨酸的味道强度值（TAV)均大于1,对鲜味和甜味呈味具有重要的贡献。偏最小二乘法分析（PLS）和Pearson相关系数关联性分析表明,电子舌的滋味特性与大部分游离氨基酸呈现正相关,其中酸味和甜味分别与苏氨酸和甘氨酸相关性显著（P<0.05）,咸味、鲜味和苦味与谷氨酸相关性极显著（P<0.01）。可利用电子鼻、电子舌和氨基酸分析技术对鱼香肉丝调料鉴别。     

不同地域特色熏鸡非盐呈味物质比较分析

为探明市售熏鸡的滋味呈味物质差异,对我国不同地域特色熏鸡产品的滋味物质进行综合评价。选取6种具有不同地域特色的代表性品牌熏鸡为研究对象,对其游离氨基酸和核苷酸进行分析,利用滋味活性值和等鲜浓度(equivalent umami concentrations,EUC)值评价滋味物质的呈味作用和鲜味强度,通过电子舌评价不同熏鸡间的滋味轮廓差异。结果表明:6种不同地域特色熏鸡的游离氨基酸、核苷酸含量及味觉特征存在显著差异(P<0.05);谷氨酸和5’-肌苷酸(5’-inosinic acid,5’-IMP)是熏鸡中主要的鲜味物质;6种熏鸡的EUC值在0.56%~16.08%范围内;电子舌结果表明鲜味和丰富性是熏鸡重要的味觉特征,其中,聊城熏鸡的丰富性特征最强,藤桥熏鸡的鲜味特征最强。综上,谷氨酸和5’-IMP是熏鸡中主要的鲜味物质,鲜味是熏鸡最主要的呈味特征,鲜味物质的差异可能与当地饮食文化和消费习惯有关。     

乌金猪与三元猪腌制的火腿品质比较

为研究自然条件发酵的乌金猪火腿与三元猪火腿的品质差异,对火腿进行pH值、粗蛋白、色差和游离氨基酸的检测与分析。结果显示：乌金组火腿与三元组火腿的pH值在整个发酵时期均处于酸性环境,且无明显差异(P>0.05),有利于保证产品的安全性;两组火腿的粗蛋白含量随着时间的增加而增加,且无明显差异(P>0.05);乌金组火腿的亮度在第360天明显高于三元组火腿(P<0.05),两组火腿的红度、黄度随时间的增加而升高;两组火腿共检测出17种相同的氨基酸,除精氨酸外,其他氨基酸均有不同程度的增加。乌金组总氨基酸含量从第0天时的46.7 mg/g增加到第360天时的236.53 mg/g;三元组总氨基酸含量从第0天时的45.53 mg/g增加到第360天时的234.9 mg/g。包括鲜味氨基酸2种、甜味氨基酸5种、苦味氨基酸7种、无味氨基酸3种,且氨基酸种类和含量变化规律无明显差异(P>0.05),两组的鲜味和甜味氨基酸含量均比苦味氨基酸含量高。在第360天时,两组火腿的谷氨酸、精氨酸、丙氨酸、缬氨酸、蛋氨酸、赖氨酸、组氨酸的TAV均远远大于1,对火腿的滋味具有较大的贡献。三元...     

海鲜调味汁风味特性差异比较分析

该研究分析了市售常见海鲜调味汁风味特性的差异,应用气相离子迁移谱（GC-IMS）、智鼻、智舌技术研究其风味特点,结合游离氨基酸分析和感官评价员的量化描述（QDA）评分,进行主成分分析和对比鉴别。乙酸乙酯在5种海鲜酱油样品中含量较高峰强度值均在6 700以上,乙酸乙酯在特级鱼露中的峰强度为566.73,在上等蚝油中的峰强度值为80.71。海鲜酱油样品中苯乙醛和异戊醇含量也较高,峰强度数值均在1 700以上。海鲜调味汁中的糠醛含量则无显著规律。海鲜味酱油中的总游离氨基酸含量最高,为0.143 nmol/μL,上等蚝油的总鲜味氨基酸含量最高,其中谷氨酸占总鲜味氨基酸总量的99.82%。电子鼻和电子舌能高效判别海鲜调味汁的气味和滋味差异,GC-IMS能快速筛选关键特征气味化合物。电子舌分析结果和QDA结果有高度一致性。蚝油和鱼露与其他样品的气味差异显著,昆布酱油和牡蛎酱油在气味上接近,牡蛎酱油和海鲜味酱油的滋味丰富性优于其他样品,蚝油的滋味丰富性最差。智能感官分析技术适于分析海鲜调味汁这类咸鲜调味料,对产品风味品质提升有实际意义。     

鸡汤及鸡肉酶解液中游离氨基酸及呈味特性的对比分析

为对比分析酶解液与鸡汤中游离氨基酸的组成及含量,采用氨基酸自动分析仪分析检测鸡汤及鸡肉酶解液中的游离氨基酸,并用电子舌分析两者滋味轮廓。结果表明,酶解液中的游离氨基酸总含量相对鸡汤显著增加,两者呈味氨基酸占总游离氨基酸（total free amino acids,TFAA）的比例相近。鸡汤中味道强度值最大的为组氨酸,其次为谷氨酸,酶解液中味道强度值较大的除谷氨酸为呈鲜味的氨基酸外,其余均为呈苦味氨基酸。鸡汤中呈鲜味和甜味氨基酸占TFAA比例之和与呈苦味氨基酸相近,而酶解液中呈苦味氨基酸占TFAA比例多达72.60%,可见鸡汤整体滋味以鲜甜为主,而酶解液整体滋味以苦味为主。电子舌主成分分析结果表明鸡汤与酶解液滋味有显著差异。     

基于电子舌的氯吡脲对草莓风味影响的研究

在草莓“甜查理”盛花后一周,喷施清水及4个浓度（2.5、5.0、10、20 mg/L）的氯吡脲,检测由此产生的草莓果实可溶性固形物、总酸、游离氨基酸、单宁等风味营养品质含量,电子舌分析技术检测酸、甜、苦、鲜、咸、涩味、苦味回味、涩味回味等味觉指标,评价氯吡脲的使用及浓度水平对草莓风味营养品质和滋味的影响,并分析电子舌在检测氯吡脲对草莓滋味影响方面运用的优势。结果表明：氯吡脲能够提高草莓果实的可溶性固形物的含量,降低总酸含量,提高固酸比值,降低游离氨基酸种类和游离氨基酸总量;低浓度（2.5、5.0 mg/L）的氯吡脲处理能降低草莓单宁含量,而高浓度（10、20 mg/L）处理会使单宁含量显著升高;电子舌味觉分析结果表明低浓度氯吡脲处理可使草莓甜味增加,酸味降低,但是咸味和鲜味及与其高度相关（相关系数均为0.99）的苦味也相应降低;游离氨基酸总量与鲜味值、单宁含量与涩味回味值、总酸含量与酸味值、固酸比与甜味值均呈正相关性。低浓度氯吡脲使用对草莓的甜味、酸味等滋味和风味组成具有正面影响,而无论氯吡脲浓度使用高低对咸味和鲜味等滋味和风味组成均有负面影响。     

红腐乳发酵过程中滋味化合物分析及电子舌鉴别

采用离子色谱、氨基酸分析仪和电子舌对不同发酵阶段红腐乳的滋味化合物及滋味特征进行检测,并对结果进行主成分分析（principal component analysis,PCA）和层次聚类分析（hierarchical cluster analysis,HCA）。结果表明,发酵过程中红腐乳样品共鉴定出17 种游离氨基酸,6 种有机酸和8 种滋味属性。总游离氨基酸含量在前酵和后酵阶段显著增加,而总有机酸含量在前酵和后酵中期显著增长（P＜0.05）。大多数的游离氨基酸和有机酸的含量在前酵和后酵阶段均显著增加（P＜0.05）。电子舌结果表明鲜味、咸味、苦味和丰富度是红腐乳的主要滋味属性。此外,滋味化合物及滋味属性的相关性分析结果表明,游离氨基酸（谷氨酸、天冬氨酸、丙氨酸、甘氨酸、组氨酸、色氨酸、苯丙氨酸、甲硫氨酸、缬氨酸）、有机酸（乳酸、乙酸、琥珀酸）及理化成分（还原糖、氨基酸态氮、氯化钠）对红腐乳的滋味特征起着重要作用。PCA和HCA结果表明,滋味化合物及滋味特征可以用来判别红腐乳的成熟度,电子舌可以作为快速评价红腐乳滋味的有效工具。     

猪骨汤中的游离氨基酸及其呈味特征分析

为了研究猪骨汤中的游离氨基酸及其呈味贡献,采用氨基酸分析仪对肋排汤、棒骨汤、脊骨汤、扇骨汤4种猪骨汤的游离氨基酸进行测定,并用电子舌分析其滋味轮廓,进行对比分析。结果表明:4种猪骨汤中均分离出17种游离氨基酸,其中有7种必需氨基酸。棒骨汤中总游离氨基酸的含量最高(24.65 mg/g),肋排汤中最低(12.61 mg/g)。4种猪骨汤中鲜味氨基酸种类最少(2种),但其中谷氨酸的相对质量分数均为16.69%~19.96%,TAV值为6.84~16.02,远高于其他游离氨基酸,对猪骨汤滋味贡献程度最大。电子舌检测分析得出,棒骨汤滋味轮廓和其他3种有差异,而其他3种差异不明显。     

不同加工年份诺邓火腿粗肽的特征与抗氧化活性

通过提取不同加工年份的诺邓火腿粗肽,测定其多肽含量、平均肽链长度(average peptide chain length,APCL)以及多肽的分子质量分布,对多肽的特征进行分析,同时测定不同加工年份诺邓火腿粗肽的游离氨基酸组成及脂质、蛋白质氧化抑制活性。结果表明:加工2年诺邓火腿粗肽的多肽含量显著高于其他2个加工年份(P0.05);加工1年、2年和3年诺邓火腿粗肽的APCL及平均分子质量没有显著差异(P0.05);加工1年、2年火腿粗肽的各类游离氨基酸含量显著高于加工3年的火腿(P0.05);加工1年、2年和3年的诺邓火腿粗肽的脂质氧化抑制率在144 h分别达到了77.95%、76.79%和75.45%,与谷胱甘肽(glutataione,GSH)的抑制效果(64.32%)存在极显著差异(P0.01);加工1年和2年诺邓火腿粗肽的蛋白质氧化抑制能力比加工3年的诺邓火腿更好,且存在极显著差异(P0.01)。     

Oligopeptides and free amino acids in Parma hams of known cathepsin B activity

Sixteen Parma hams were manufactured following regular standard procedures up to the 13th month of processing and then divided into two groups according to established levels of cathepsin B activity in fresh hams. Each group was selected in order to include the same number of hams with low or high cathepsin B activity. The two groups were further split to be kept for an additional month at two different temperatures (18 and 26 °C) and then analysed for proximate composition, free amino acids and oligopeptides (MW<500 Da). All hams were analysed by sensory analysis (panel test) to be scored for saltiness, bitterness and the flavour of “ageing”. Fresh hams with higher cathepsin B activity were shown by means of two-way ANOVA to yield dry-cured hams more proteolysed (P<0.01), while the higher temperature of the final ageing period seemed to play a major role in lowering ham dryness. Bitterness was particularly well perceived in most proteolysed hams and it was significantly related to the higher amounts of lipophilic amino acids and lipophilic oligopeptides (identified by mass spectrometry), in agreement with the literature. Thus, the endopeptidase activity in fresh hams, together with the presence of specific lipophilic amino acids and oligopeptides in dry-cured hams, can be regarded as a molecular marker of bitter taste development.     

SPME-GC-MS结合ROAV分析腌制时间对大河乌猪火腿挥发性风味物质的影响

本研究旨在分析腌制时间对大河乌猪干腌火腿风味品质的影响,揭示干腌火腿的特征风味物质。将172只大河乌猪鲜腿分为4个组,采用传统方法加工后,每组随机抽取4只火腿,采用固相微萃取-气相色谱-质谱（Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry,SPME-GC-MS）技术并结合相对气味活度值（Relative Odor Activity Value, ROAV）法和主成分分析（Principal Component Analysis,PCA）法对大河乌猪火腿挥发性风味物质进行分析。结果表明:腌制15、18、21、24 d的挥发性成分的种类分别为57、57、54、41种,共鉴定77种同类挥发性成分;聚类分析表明不同腌制时间的大河乌猪火腿挥发性物质的组成及相对含量存在较大的差异;ROAV分析表明醛类和醇类对风味贡献最大;PCA表明1-辛烯-3-醇、异戊醛、正辛醛、双戊烯是不同腌制期火腿中含量变化最明显的挥发性物质。腌制时间对大河乌猪干腌火腿风味品质有一定影响,研究可为火腿品质控制及风味改良提供理论依据。     

Relations between compositional traits and sensory qualities of French dry-cured ham

The left hams of 20 pig carcasses were processed by dry-curing for either 179 (n = 10) or 273 days (n = 10). The Biceps femoris was taken at the end of the processing and submitted to chemical and sensory analyses. The following chemical traits were determined: pH, moisture, salt content, fatty acid content and composition of lipid classes (triglycerides, phospholipids, free fatty acids), nitrogen fractions (soluble and insoluble protein, non-protein nitrogen, free amino acids) and volatile compounds. Sensory analysis was performed by a panel of 12 trained members, who scored texture traits (firmness, dryness, fibrousness, mellowness), taste (salty, acid), intensity of aromas (typical of dry ham, fresh meat, fat, cured meat, rancid, metal), persistence of dry ham aroma, persistence of taste after deglutition, persistence of astringency, persistence of metallic taste. The sensory qualities of dry-cured ham showed noticeable changes between days 179 and 273. Firmness, dryness and intensities of aromas typical of dry-cured ham and cured meat were enhanced with time. Neither pH, moisture nor salt content played a noticeable role in determining the sensory quality of dry-cured ham. Among the volatile compounds, the levels of several ketones and 1-butanol were significantly correlated with the aromas of dry ham and cured meat, while rancid aroma was related to aldehydes, ethylacetate, 2,3-pentanedione and nonane. Therefore, the aromas of dry ham and cured meat appeared to be determined mainly by the products of lipid oxidation. However, they were related also to unidentified volatile compounds, whose identification would be of particular interest.     

Micronutrients in Italian ham: A survey of traditional products

The study provides original analytical data on the micronutrient profile of some traditional Italian hams, representative of the major ham categories produced in Italy: 4 dry-cured hams (Modena, Nazionale, Parma, San Daniele), 3 cooked hams (Cotto, Scelto, Alta Qualità), 1 smoked ham (Speck). Data on macronutrients (protein, lipid, moisture), energy, trace elements (Fe, Zn, Cu, Mn, Se), B vitamins (B1, B2, PP, B6, B12) and vitamin E level in the 80 Italian hams sampled are reported. Smoked and dry-cured ham were the richest sources of Fe, Zn and Se and, among vitamins, dry-cured ham had the highest level of B2, PP, B6 and B12; cooked ham provided the lowest energy intake. The contribution of ham to micronutrients recommended dietary allowances was estimated: a ham portion (50 g) was a good source especially of Zn and Se providing over 12% of RDA of both; among B vitamins, dry-cured ham greatly contributed to B1 and B6 vitamins RDA (both over 30%).     

Identification and significance of the N-terminal part of swine pyruvate kinase in aged Parma hams

Within a project aimed at studying the peptide fraction in dry-cured Parma hams, a peptide was purified by means of reversed phase-high performance liquid chromatography (RP-HPLC) and identified by its molecular mass and amino acid sequence analysis. The peptide showed a very high degree of homology with the N-terminal part of different mammalian pyruvate kinases reported in databases and was accordingly identified as the N-terminal part of swine pyruvate kinase, whose sequence had never been reported before. The peptide was determined quantitatively by comparison with a suitable internal standard (Phe-Phe) in commercial ham samples with different age degrees. The peptide was found to be ubiquitous in Parma ham and its amount to increase during ageing even if a large variability was found within each assayed maturing time. The correlation found with the ham proteolysis degree (P<0.01) suggests that this peptide is related to the endopeptidasic activity. The peptide did not show a significant relationship with bitterness perception in assayed dry-cured ham, in agreement with the hypothesis that this taste is more related to free amino acids and low molecular weight peptides.     

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.     

The effects of castration on the eating quality of dry-cured ham

The influence of the castration of entire male pigs on the eating quality of dry-cured ham was evaluated. Forty-eight dry-cured hams (435-day aged) were studied from entire and castrated males of two different crossbreeds. The proximate composition of the meat and the androstenone, indole and skatole fat content were determined. The entire hams were classified according to the androstenone and skatole content. Sensory analysis was carried out by a trained panel, evaluating marbling, juiciness, saltiness, graininess, toughness, overall flavour, boar odour and boar flavour. Also carried out was a preference and acceptability paired test by consumers. Castration increased meat fattening and reduced the androstenone and skatole levels of the fat. Significant differences (P<0.05) were found between entires and castrates for the average values given in all the sensory attributes studied. The dry-cured ham from castrates was scored as more flavoured, more marbled and softer. It was also perceived as less grainy, less salty and having less boar odour and flavour. The sensory perception of boar odour was more intense than that of flavour in dry-cured ham and appears to be related to the level of androstenone and skatole in fat. Dry-cured ham from castrated males was also more accepted and more preferred by consumers, especially women and habitual consumers. Castration of male pigs contributes to improve the quality of dry-cured ham. The rejection caused by boar odour and flavour is reduced, improving the overall flavour, texture and juiciness. In addition, the saltiness is less pronounced in ham from castrates. For this reason, the production of high quality dry-cured ham will have to shoulder the extra costs associated with processing castrated pigs.     

Characterization and differentiation of Italian Parma,San Daniele and Toscano dry-cured hams: A multi-disciplinary approach

This study aimed at characterizing the sensory quality of Italian PDO dry-cured Parma, San Daniele and Toscano hams, applying a multi-disciplinary approach. Ham sensory profile as well as physico-chemical, aromatic, morphological and textural characteristics was investigated. There was a great difference between Toscano ham and Parma and San Daniele hams, which were more similar even though differentiated. Toscano ham showed higher scores for pork-meat odor, saltiness, dryness, fibrousness and hardness; accordingly, this ham was described by a high NaCl content and by high values of instrumental hardness, cohesiveness, gumminess and chewiness. Parma ham was characterized by a cured flavor, whereas San Daniele ham showed a wider fatty area and higher pH values. Parma and San Daniele hams were also described by higher values of sweetness, RGB color values and water activity. Sensory characteristics evaluated by trained assessors were correlated to instrumental measures, indicating that instrumental devices can be effectively applied for dry-cured ham characterization.     

Analysis of raw meat to predict proteolysis in Parma ham

Four hundred and thirty-seven pigs (223 purebred Italian Large White, 97 Italian Landrace, and 117 Duroc), were studied to examine the effect of breed on meat quality and assess the possibility of relating proteolysis of dry-cured hams to raw meat quality. The Duroc pigs had intramuscular fat contents and water holding capacities (M. Semimembranosus) significantly higher than those of the Large White and Landrace. The latter had a significantly higher pH(24h) and cathepsin B activities significantly lower than the Duroc breed. The dry-cured hams (M. Biceps femoris) from the three breeds were significantly different in proximate composition, proteolysis and weight loss at the end of ageing. Data for green hams (including salt content) were used to compute a model to fit the proteolysis of the corresponding dry-cured hams. The variables included in the model (R(2)=0.53 and P<0.01) were cathepsin B activity of raw ham, pH(24h), weight loss after the first salting step, and the salt content of the dry-cured ham. The raw hams with the highest cathepsin B activities, the lowest pH(24h), and the highest weight loss after the first salting were those in which greatest proteolysis occured.