青海藏系绵羊肉中肌苷酸、肌苷的含量测定

采用高效液相色谱法对藏系绵羊肉中的肌苷、肌苷酸进行定量分析。色谱柱：Kromasil C18 柱(4.6mm× 250mm,5μm);流动相：甲醇-水(95:5,V/V);流速1ml/min;紫外检测波长：254nm。结果表明：肌苷酸、肌苷分别在12.96～207.50mg/L和1.40～22.42mg/L范围内呈线性关系,回收率分别为97.98%、98.26%,该方法可用于动物肌肉组织中的肌苷酸、肌苷含量的测定。     

不同贮藏条件下武定鸡肌肉肌苷酸及相关核苷酸含量的变化研究

实验对150日龄武定母鸡胸肌在不同贮藏温度和时间对其肌苷酸及相关核苷酸的含量影响进行分析,结果表明:18℃贮藏条件下,IMP含量在宰后4 h达到最高值2.00 mg/g,自8 h开始含量显著下降(P<0.05);IMP前体物含量在2 h达到最高测定值1.46mg/g,之后逐渐下降;IMP降解物含量随时间延长逐渐升高;ATP总代谢物含量在4 h含量达到最高值5.71 mg/g,之后逐渐下降;K值随时间延长而增大。4℃贮藏条件下,IMP含量随时间延长呈先升后降规律,24 h含量达到最高1.46 mg/g;IMP前体物含量也存在类似的变化规律,24 h含量达到最高0.91 mg/g,自第3 d开始显著下降(P<0.05);IMP降解物、ATP总代谢物和K值随时间的延长而增加。武定鸡肌肉在相同贮藏温度下,贮藏时间越长,肌苷酸含量越低;贮藏温度越低,肌苷酸降解越缓慢,ATP的整体代谢过程持续时间越长。     

高效液相色谱法测定鸡精中呈昧核苷酸含量

建立了高效液相色谱法测定鸡精中呈味核苷酸含量方法。样品经水超声提取。采用液相色谱仪进行检测,色谱柱为C18色谱柱,流动相为V（甲醇）：V（乙酸铵溶液）=5：95,检测波长为254nm。结果表明,鸟苷酸二钠和肌苷酸二钠分离效果良好（R=2．O）,可分别准确定量。在1μg／ml-100μg／ml范围内鸟苷酸二钠和肌苷酸二钠回归方程分别为：Y=10．6825X＋1．5953,r=0．99995;Y=8．9096X＋0．13404,r=0．99997。方法回收率为99．1％、98．7％。     

网箱海养卵形鲳鲹肌肉中呈味物质分析评价

测定网箱海养卵形鲳鲹肌肉中呈味核苷酸、游离氨基酸、无机离子和甜菜碱等主要呈味物质的含量,并采用味精当量值和呈味强度值来评价这些呈味物质的呈味强度。结果表明：网箱海养卵形鲳鲹肌肉的呈味核苷酸总量为379.9 mg/100 g,其中以5’-肌苷酸（5’-inosine monophosphate,IMP）含量最高,高达373.59 mg/100 g;游离氨基酸总量为256.60 mg/100 g,以甘氨酸（136.34 mg/100 g）、丙氨酸（27.47 mg/100 g）、谷氨酸（16.84 mg/100 g）贡献最大;K＋、Na＋、PO43－和IMP为主要呈味离子,甜菜碱含量为1.95 mg/g;呈味核苷酸和鲜味氨基酸具有一定的协同效应,其味精当量值为7.92 g MSG/100 g,呈味强度高达264。结果表明：IMP、甘氨酸、谷氨酸、丙氨酸、K＋和PO43－等为网箱海养卵形鲳鲹肌肉中主要滋味贡献物质,且IMP与甘氨酸和丙氨酸具有协同交互作用,这些是卵形鲳鲹肌肉呈现鲜味的物质基础。     

云南剥隘鸡与河南肉鸡肌肉中肌苷酸含量的 比较研究

目的比较研究不同月龄、性别的云南剥隘鸡与河南肉鸡肌肉中不同胴体部位的肌苷酸含量。方法随机选取健康5月、7月龄左右的云南剥隘鸡、河南肉鸡,公母各10只,屠宰取胸肌和腿肌待测。采用高效液相色谱法测定出不同月龄(5、7月龄)、性别及胴体部位(胸肌、腿肌)的云南剥隘鸡和河南肉鸡肌肉中肌苷酸含量。结果云南剥隘鸡、河南肉鸡肌肉中肌苷酸含量分别为2.4374~3.3192 mg/g、2.2095~3.0220 mg/g;5月、7月龄的云南剥隘鸡肌肉中肌苷酸含量均显著高于同月龄的河南肉鸡(P0.05);云南剥隘鸡肌肉中肌苷酸含量高于同性别的河南肉鸡,其中2种品种的母鸡肌肉中肌苷酸含量差距更显著(P0.05);云南剥隘鸡胸肌、腿肌中肌苷酸含量均显著高于相同胴体部位的河南肉鸡(P0.05)。结论不同月龄、性别、胴体部位对2个品种鸡肌肉中肌苷酸含量的差异性均产生显著影响,云南剥隘鸡肌肉中肌苷酸含量要高于相同条件下的河南肉鸡。     

保活运输过程中武昌鱼肌肉品质的变化

以武昌鱼为原料,采用超高效液相色谱、色彩色差计、紫外分光光度计等技术手段测定有水运输过程中（3、6、12、24 h）武昌鱼肌肉品质的变化。结果表明：运输3 h的武昌鱼pH值、持水性、白度（W）、亮度值（L*）、红度值（a*）、乳酸含量、肌糖原含量、5’-三磷酸腺苷（ATP）及其代谢关联产物总含量分别为6.57、70.33%、52.22、52.27、0.29、4.50 mg/g、1.46 mg/g、909.25 mg/100 g;随着运输时间延长至24 h,pH值先显著上升后显著下降到6.33（P＜0.05）,乳酸含量先显著下降然后上升到3.81 mg/g,持水性逐渐上升到76.05%再下降至73.33%,W和L*逐渐下降至47.64和47.71,而a*显著升高至1.31（P＜0.05）,肌糖原含量逐渐下降至1.25 mg/g,ATP及其代谢关联产物总含量上升至1 116.62 mg/100 g,其中ATP含量下降至62.43 mg/100 g,鲜味物质5’-次黄嘌呤核苷酸含量上升至747.91 mg/100 g,苦味物质次黄嘌呤核苷和次黄嘌呤含量分别上升至156.12、63.28 mg/100 g。以上研究结果表明,受应激影响,武昌鱼在保活运输中肌肉品质随时间显著改变。     

旧报纸碎浆过程中产生的溶解与胶体物质的研究

系统研究了旧报纸碎浆过程中释放的溶解与胶体物质(DCS)。利用气相色谱-质谱联用技术(GC-MS)分析了在碎浆过程中产生的碳水化合物、树脂酸和脂肪酸,并用紫外分光光度法定性定量测定了木素含量。结果表明,DCS中溶解性物质占较大比例,碎解过程中释放出最多的糖类是木聚糖,而亲脂性抽出物中树脂酸的含量高于脂肪酸的含量,DCS中的木素主要以溶解木素的形式存在。     

茅台酱香型酒曲中黄酮、多酚含量的测定

建立酱香型酒曲中总黄酮、多酚含量测定方法。以槲皮素为对照品,采用紫外分光光度法测定茅台酱香型酒曲中总黄酮含量;以没食子酸为对照品,用Folin-Ciocateau比色法测定酒曲中多酚含量。结果表明,槲皮素及没食子酸对照品分别在浓度0.0210~0.1050 g/L(r=0.9976)和0.00051~0.00565 g/L(r=0.9997)范围内与吸光度呈良好线性关系,茅台酱香型酒曲中黄酮和多酚含量分别为9.70 mg/g和1.84 mg/g。此方法简便易行,重现性好,结果稳定、准确,适用于酱香型酒曲总黄酮和多酚的定量测定。     

牛奶中共轭亚油酸含量的紫外分光光度测定方法

研究了牛乳中共轭亚油酸含量的紫外分光光度测定方法。利用紫外分光光度计,先建立标准曲线与回归公式,再将牛奶样品提取、甲酯化后,进行紫外检测。结果表明,共轭亚油酸甲酯的最大吸收波长是234nm;共轭亚油酸浓度的有效测定范围是0.00856-0.0428mg/mL;吸光度与共轭亚油酸浓度间的回归公式为Y=52.602X 0.0917(R2=0.9862);得出共轭亚油酸浓度与吸光度之间的经验公式为:共轭亚油酸浓度C(mg/mL)=0.019×吸光度(ABS);并且推出了利用紫外分光光度法测定牛奶中共轭亚油酸含量的计算公式。同时,检验了几种市售牛奶中共轭亚油酸,其平均含量为1.64mg/g。     

不同贮存温度对兴凯湖翘嘴鲌肌肉肌苷酸含量的影响

采用高效液相色谱技术,测定在(20±1)、4、-20℃贮存条件下,兴凯湖翘嘴鲌(Culter alburnus)野生群体和养殖群体肌肉组织中肌苷酸(IMP)含量及其变化。结果表明,野生群体新鲜肌肉组织中IMP含量为1.6002mg/g,养殖群体新鲜肌肉组织中IMP含量为1.2487mg/g,野生群体IMP含量显著高于养殖群体(p0.05);与4℃相比,(20±1)℃贮存条件下肌肉组织IMP含量降解速度更快;-20℃低温冻存,肌肉组织中IMP含量高于(20±1)℃条件下新鲜肌肉组织,且降解缓慢;贮存时间对鱼肉肌苷酸降解速率有显著影响,长时间的贮存会降低食用鱼肉中肌苷酸含量,但短时间(5d)的冻存后可提高鱼肉中肌苷酸含量。实验结果表明:(20±1)℃条件下贮存不超过4h;4℃条件下贮存不超过12h;-20℃条件下贮存,5d左右食用最佳。     

BARLEY AND MALT TANNINOGENS AND BEER QUALITY

Anthocyanogen and catechin contents (tanninogen values) were determined for ten two-row and thirteen six-row barleys and for their corresponding malts. Four barley-malts were then selected for brewing, one with high, one with low, and two with intermediate tanninogen contents. The brews were made using bottom-fermenting (lager) as well as top-fermenting (ale) yeasts, both at 50–55° F. and at 68° F. The quality of the beers, as expressed by standard analyses and flavour evaluation, is discussed in the light of the tanninogen contents of the barleys and the different brewing parameters (yeast type and fermentation temperature).     

新合纤及其制造加工技术

说明了日本新合纤(新聚酯)的发展阶段,介绍了国外(日本西欧和美国)新合纤的市场情况,指出了日本在新合纤领域目前处于世界最先进水平。概括了新合纤制造加工技术及1990～1992年间日本各合成纤维厂商推出的新合纤产品。最后指出了新合纤存在的某些缺点。     

姜与人体营养健康

对姜的营养、保健功能及其在日常生活中的应用进行了介绍，更利于推动我国调味品业的进一步研究与开发。     

CHEMICAL AND ANTIOXIDANT PROPERTIES OF CULTIVATED AND WILD FRAGARIA AND RUBUS BERRIES

ABSTRACT

Content of individual sugars, organic acids, total phenolics (TPH), some important phenolic compounds (kaempferol, myricetin, quercetin, and ellagic acid) and total antioxidant capacity (TAC) in the fruits of strawberry, raspberry and blackberry were studied. A comparison was made between cultivars and wild relatives of each species (Fragaria vesca L., Rubus idaeus L. and Rubus fruticosus L.). The main sugars found were fructose and glucose both in the fruits of wild species and the studied cultivars. Citric acid was determined to be the major organic acid in most of tested berries with the exception of blackberry cultivars, where malic acid was dominant. The content of individual phenolic compounds varied among the wild species, as well as among the studied cultivars. Ellagic acid content was higher in F. vesca, R. idaeus and R. fruticosus (122.5 µg/g FW, 12.71 µg/g FW and 61.7 µg/g FW, respectively) than that obtained in analyzed cultivars. Overall, TPH expressed higher values in the wild strawberry and blackberry species in comparison to the studied cultivars, and consequently, the highest levels of TAC were recorded in F. vesca (5.78 mg asc/g FW), followed by R. fruticosus (4.95 mg asc/g FW).

PRACTICAL APPLICATIONS

In recent years, both wild and cultivated berries have become very attractive for consumers because of potentially beneficial phytochemicals contained in these fruits. Fruit nutritional quality can be described by standard quality parameters (sugars and organic acids), and the analysis of antioxidant capacity influenced by specific related compounds. The importance of flavonoids and other phenolics have been suggested to play a preventive role in the development of cancer and heart disease. A significant positive correlation observed in this study between total phenolics and total antioxidant capacity indicate the need for the use of wild species in the breeding programs of small fruits, especially strawberry and blackberry, in order to increase their nutritive value and the health benefits.     

Tencel机织物的染整加工及所用染化料

Ｔｅｎｃｅｌ纤维易于原纤化和很高的横向膨润性对染整加工设备选型、工序安排、染化料选用提出了很高的要求，关键的助剂是润滑剂、纤维素酶、柔软剂、树脂整理剂、防原纤化助剂，于是详细讨论了Ｔｅｎｃｅｌ机织物的前处理、初级原纤化、酶处理、染色、二次原纤化和柔性、树脂整理及染化料的应用。     

INSTRUMENTAL AND SENSORY TEXTURE ASSESSMENT AND FRACTURE MECHANISMS OF CHEDDAR AND CHESHIRE CHEESES

Textural attributes of Cheddar and Cheshire cheeses, falling within narrow compositional ranges, were assessed by sensory panels, and from force-compression curves generated by compression between two plates, and, for Cheddar cheese only, by penetrometry. Individual sensory measurements did not relate well to any instrumental one, and were better at discriminating between cheeses. Samples of each cheese variety were fractured in different ways and the fracture surfaces were examined in a scanning electron microscope. Fracture surfaces were formed by cutting directly through the matrix, tearing of the matrix along planes high in fat or cracking at grain boundaries. It is suggested that consideration of fracture mechanism may aid the selection and development of useful instrumental methods for texture assessment of cheese.     

THIOLS AND DISULPHIDES IN QUIESCENT AND GERMINATING BARLEY GRAINS,BOTH DORMANT AND MATURE

Reduced and oxidised glutathione, cysteine, cystine and traces (too small to quantify) of γ-glutamyl-cysteine and cysteinylglycine were detected, in about the same amounts, in extracts of the embryos of dormant and mature barleys. During micromalting the levels of the thiols and disulphides altered in various ways, but altered in the same ways in dormant and mature samples of grain until germination began. An early decline in the glutathione content of embryos was mirrored by a rise in the amount in degermed grains. Histochemical tests and analyses of isolated tissues showed that in the quiescent grains thiols were concentrated in the embryo (particularly the scutellum) and in the aleurone layer and isolated embryos released thiols into an incubation medium. We conclude that the endogenous thiols and disulphides are not obviously involved in the regulation of dormancy.     

壳聚糖及其衍生物在鲜切果蔬和食品保鲜中的应用进展

对壳聚糖特有的分子结构和良好的防腐保鲜性能及其在鲜切果蔬和食品保鲜中的应用研究作一论述，展望其应用前景。