天祝白牦牛肉挥发性风味成分的SPEM/GC/MS测定

采用顶空固相微萃取技术(SPME),提取天祝白牦牛和当地黄牛肉中的挥发性风味物质,并采用气相色谱和质谱联用法(GC-MS)对风味物质进行了定性分析和峰面积相对含量的测定.结果表明:白牦牛肉的主要挥发性风味物质的种类有62种,而当地黄牛只有42种;影响白牦牛肉风味的主要挥发性物质为氯仿(清香味)、辛醛(鲜香味)、1,2-二苯甲酸-2-甲基丙酯(油香味)和1-乙基-碳三硫酯(清香);影响当地黄牛肉风味的主要挥发性物质为1-丙氧基-2-丙醇(刺鼻清香)、2-烯基壬醛(脂肪香味)、2-羰基壬酸甲酯(脂香味)和2,4,6,10-四甲基十五烷酸甲酯(肉汤香味).     

麻味与麻姜味营养型核桃调味油的配制

为全面提升核桃深加工技术,延长产业链、提高核桃产业整体经济效益,采用气质联用测定核桃油、紫苏油、花生油、菜籽油、米糠油、芝麻油等原料油内脂肪酸的构成,利用 Matlab 软件将核桃油与紫苏油等原料油调配成脂肪酸合理构成的调和油,再加入花椒精油、姜精油进行风味调配,通过正交试验优化麻姜味营养型核桃油的配方。结果表明：脂肪酸合理构成的调和油配方为核桃油30％,紫苏油1．64％,菜籽油41．13％,花生油27．24％;麻味营养型核桃调味油的花椒精油添加量为16％;麻姜味营养型核桃调味油的花椒精油和姜油添加量分别为16％和0．9％。该类调味油呈自然棕黄色,外观澄清透明,理化指标均符合国家一级压榨油标准,口感滋味宜人,兼有花椒的清新麻香味和生姜的辛辣芳香味。     

美拉德反应在风味剂中的应用

文章论述了美拉德反应机理、影响因素以及肉风味形成的途径,并简述了美拉德反应在宠物风味剂生产中的应用及效果。     

Taste effects of oligopeptides in a Vietnamese fish sauce

ABSTRACT: A Vietnamese fish sauce Nuoc mam used in the present study was rich in oligopeptides of which nitrogen content accounted for 20% of total nitrogen. The high-molecular-weight peptide fractions fractionated by ion-exchange chromatographies and ultrafiltration enhanced sweetness and umami as well as sourness and bitterness of the fish sauce, and increased several flavor characteristics including continuity, first taste and aftertaste. Thus, it is apparent that large amounts of peptides produced during the long-term fermentation of fish sauce are responsible for the complicated taste of the sauce. From each fraction, 17 peptides in total were isolated and determined for their amino acid sequences. These di-, tri- and tetra-peptides synthesized by solid- or liquid-phase method gave any one of bitter, sour, umami taste, or practically no taste in the absence of salt. In the presence of 0.3% NaCl, however, almost all peptides showed sweet and umami tastes. Other than these 17 peptides, there existed many other kinds of peptides in the fish sauce. Thus, these peptides are thought to contribute to the overall taste of the fish sauce.     

基于ADAMS/Insight的轿车悬架定位参数优化研究

基于某A级轿车悬架参数,在ADAMS/Car中建立前悬架系统精确模型。通过双轮同向跳动实验,分析悬架定位参数随车轮跳动的变化情况。针对悬架在跳动实验过程中出现的前束角变化规律不合理且主销内倾角、外倾角变化范围较大等问题,运用Insight模块对优化目标进行设定并进行多次修改和迭代计算,找出最优结果。     

广东不同产地柠檬果肉中挥发性风味物质 比较和柠檬烯测定方法的研究

采用顶空-固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）的方法分析了柠檬果肉中的挥发性风 味物质,并优化条件。对河源产尤力克、广州产里斯本、广州产尤力克柠檬进行比较,建立了采用顶空-气相色谱-质 谱（HS-GC-MS）直接测定柠檬果肉中D-柠檬烯含量的方法。结果表明,50/30 滋m DVB/CAR/PDMS 萃取头的吸附效 果最好,D-柠檬烯是柠檬果肉中挥发性风味物质的主体。广州产里斯本柠檬的挥发性风味物质种类最多,且含量较 高。测定D-柠檬烯含量时,采用25 mL 顶空瓶,50益平衡30 min,选取7 个不同的柠檬果肉质量,可得到线性良好的 标准曲线,因此采用真实果实制作标准曲线的方法是可行的。用该标准曲线对3 种柠檬中D-柠檬烯的含量进行测 定,发现广州产里斯本中D-柠檬烯含量最高。     

Genetic analysis of pungency and soluble solids in long-storage onions

Summary Pungency and soluble solids are important quality attributes of onion. An eight-parent diallel over two years indicated a preponderance of additive genetic variation for both attributes. Variation among years was significant for pungency but not solids. No reciprocal cross differences were noted for pungency or solids. Generatio means analysis for four crosses over two years had a good fit with a simple additive-dominance model to explain the inheritance of both traits in most cases. Both diallel and generation means analyses demonstrated some dominance for low pungency. Broad sense heritability estimates averaged 0.64 for pungency and 0.83 for soluble solids. Selection was effective for increasing and decreasing pungency in derivatives of five crosses. Pungency and soluble solids were correlated among parental inbreds and hybrids but not within F₃'s. The additive control and heritability suggest that onion pungency and soluble solids can be effectively and independently selected.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

茉莉酮酸脂与高氧处理对冷藏水蜜桃的风味影响

以水蜜桃品种为试材，设低Ｏ２，高Ｏ２，茉莉酮酸甲脂（Ｍｊ）以及Ｍｊ和高Ｏ２混合（Ｍｉｘ）４个处理，以空气（Ａｉｒ）处理作对照。处理后，放在２℃的条件下冷藏。采样测定冷藏后果肉组织内的次生代谢物质（异味物质）。结果表明，与对照相比，高Ｏ２和Ｍｉｘ处理均有效抑制冷藏前、中期乙烯和ＣＯ２产生；低氧处理，使整个冷藏期乙烯和ＣＯ２的产生受抑；单独Ｍｊ处理，前期乙烯释放受抑，但加快了整个冷藏期ＣＯ２的释放；Ｍ     

外源酶辅助发酵加工藏茶的工艺研究

为解决藏茶加工过程中存在的渥堆时间长及微生物污染导致的安全隐患,探索藏茶加工新工艺,以绿毛茶为试验原料,添加从土豆中制备的外源酶,结合湿热转化加工藏茶,通过响应面分析研究最佳工艺参数,并与传统工艺制成的藏茶进行感官及滋味、色素与香气成分的对比分析。结果表明:以酶添加量80 U·g^-1、茶坯含水量60%、发酵温度34 ℃、发酵时间7 h进行酶促转化,而后在温度80 ℃条件下湿热转化60 h工艺制成的藏茶比传统工艺藏茶的滋味更醇和,汤色更红亮,香气更纯正,无酸馊和风霉味。该工艺制成藏茶比传统藏茶水浸出物增加11.72百分点、茶黄素增加0.05百分点、茶红素增加1.47百分点、茶褐素增加0.28百分点,并产生了较多的花果香型香气物质,其中,具有百合花香、玉兰花香、铃兰香和木香的β-芳樟醇增加1.69百分点,具有木香花香的α-雪松醇增加0.49百分点,具有果香的香叶基丙酮增加2.27百分点,极大地改善了茶叶的风味品质。