连续51天服用褪黑激素对小鼠肾脏、心肌与脑部分生化指标及体重变化的影响

观察连续51d服用褪黑激素(MT)对机体抗氧化系统及体重增长的影响。方法:以雄性昆明种小鼠为实验对象,连续51d服用MT建立动物模型。分别测试肾脏、心肌与脑超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量、总抗氧化能力(T-AOC)及整个服用期间的体重变化情况。结果:连续51d服用MT后,MT组小鼠体重及体重增量明显小于对照组(p<0.05)。小鼠肾脏SOD活性与T-AOC,心肌T-AOC及脑SOD活性与T-AOC显著升高(p<0.05～0.01),脑CAT活性及肾脏、心肌与脑MDA含量显著下降(p<0.01),但对肾脏POD活性与CAT活性,心肌SOD活性、POD活性与CAT活性以及脑POD活性无显著性影响(p>0.05)。结论:MT具有很强的抗氧化能力,对机体的抗氧化系统有明显的辅助作用,对小鼠体重的正常生长发育存在一定程度的抑制。     

燕麦β-葡聚糖对脂多糖引起的小鼠生长和血液生化指标的影响

目的:研究燕麦β-葡聚糖对注射脂多糖小鼠的生长和血液生化指标的改善作用。方法:将50只C57BL/6小鼠随机分成5组,每组10只。脂多糖组每天腹腔注射用生理盐水稀释的脂多糖1.5 mg/(kg bw),正常对照组每天腹腔注射相同剂量的生理盐水。正常对照组和脂多糖组都饲喂不含燕麦β-葡聚糖的SPF级饲料。脂多糖+低燕麦β-葡聚糖含量组、脂多糖+中燕麦β-葡聚糖含量组和脂多糖+高燕麦β-葡聚糖含量组除每天腹腔注射脂多糖1.5 mg/(kg bw)外,分别在SPF级饲料中添加1%,5%和10%的燕麦β-葡聚糖。连续腹腔注射脂多糖6周后,对生长指标摄食量、饮水量、排泄量和体重及血液指标内毒素、糖耐量、胰岛素抵抗、总胆固醇和甘油三酯进行测定。结果:燕麦β-葡聚糖能导致注射脂多糖小鼠摄食量的增加和饮水量的减少;抑制腹腔注射脂多糖6周,小鼠体重增加和血液内毒素水平上升;改善其糖不耐受性、胰岛素抵抗和血液总胆固醇水平,而添加燕麦β-葡聚糖的量对注射脂多糖引起的小鼠生长和血液生化指标的影响不成量效关系。结论:燕麦β-葡聚糖能够改善脂多糖引起的小鼠摄食量以及体重生长指标和血液生化指标的变化。     

皮质醇激素和血液生化指标变化对猪肉劣质肉的指示作用

为寻找猪肉劣质肉的指示指标,比较了不同质量猪肉对应皮质醇激素和血液生化指标的变化。结果表明,劣质肉中白肌肉(PSE)对应生猪血糖浓度显著高于正常肉(RFN)(P<0.05),劣质肉中黑干肉(DFD)对应生猪皮质醇浓度显著高于RFN肉(P<0.05)。说明血糖可作为劣质肉中PSE肉的重要指示指标,当宰前血糖浓度达到(17.21±3.12)mol/L时,可能产PSE肉;皮质醇可作为劣质肉中DFD肉的重要指示指标,当宰前皮质醇浓度达到(512.70±49.9)nmol/L时,可能产生DFD肉。     

环境热应激对绵羊肉品质及血液生化指标的影响

为了解热应激对绵羊肉品质及血液生化指标的影响,选择鲁中肉羊作为实验对象,人工调控养殖环境对其施加热应激处理,比较组间羊肉品质和血液生化指标。结果显示：热应激对羊肉在45 min和贮藏24 h时的pH值以及蒸煮损失均无显著影响;滴水损失、剪切力以及在45 min和24 h的亮度值(L^*)、红度值(a^*)和黄度值(b^*)在2组间均存在显著差异(P<0.05);对照组在各方面感官评分均优于应激组;扫描电镜结果显示应激组肌肉纤维更为松散。应激组血液中促甲状腺素释放激素(thyrotropin-releasing hormone,TRH)、甲状腺素、皮质醇(cortisol,Cor)含量的全天平均水平相较于对照组均极显著降低(P<0.01);肾上腺素、胰岛素(insulin,Ins)含量显著上升(P<0.05);三碘甲状腺原氨酸、促肾上腺皮质激素含量无显著差异。免疫球蛋白A(immunoglobulin A,IgA)含量应激组相较于对照组显著下降(P<0.05),IgG、IgM和白细胞介素4水平无显著差异;...     

DHA藻油调和油对SD大鼠血液常规和血液生理生化指标的影响

探讨了DHA藻油调和油对SD大鼠血液常规和血液生理生化指标的影响。以灌胃方式给SD大鼠饲食DHA含量不同的DHA藻油的调和油,饲养8周后,对SD大鼠的血液常规和血液生理生化指标进行了检测。结果表明:DHA藻油调和油对SD大鼠血液常规和血液生理生化指标中的大部分指标均没有显著影响,这些指标基本上都处于正常范围内,但在TC、LDL上有下降趋势,说明DHA藻油调和油对血管疾病具有一定的功效。     

烟酸铬对肉鸡生产性能、胴体品质及和血液生化指标的影响

选择1日龄艾维菌商品肉鸡360羽，随机分成3组，每组3个重复，每个重复40羽，试验期6周，研究了在日粮中分别添加0，0．2，0．4mg/kg铬量的烟酸铬对肉鸡生产性能，胴体品质及血液生化指标的影响，结果表明：在0－6周龄的肉鸡日粮中添加不同水平的烟酸铬对肉鸡生产性能无显著影响（P＞0．05）。但添加烟酸铬可明显改善胴体品质，显著提高胸肌率（P＜0．05）、降低腹脂率（P＜0．01），对肝脂率、屠宰率，净膛率却无显著影响（P＜0．05），及甘油三酯的含量（P＜0．01），并显著提高血清中高密度脂蛋白－胆固醇的质量浓度（P＜0．05）。     

果寡糖对不同生长阶段固始鸡血液生化指标的影响

选用1日龄固始鸡公雏150只,随机分成5个处理组,对照组饲喂基础日粮,试验组在基础日粮的基础上分别饲喂添加0.3%、0.5%、0.7%、0.9%果寡糖的饲粮.于21日龄和42日龄分别研究果寡糖对固始鸡血液生化指标的影响.结果表明,(1)0.5%果寡糖能显著提高21日龄和42日龄固始鸡血清总蛋白(P<0.05)、清蛋白(P<0.05)和血清无机磷(P<0.05),同时显著提高21日龄血清球蛋白(P<0.05)和血糖含量(P<0.05);(2)0.3%和0.5%果寡糖能显著提高21日龄谷丙转氨酶(GPT)(P<0.05)和谷草转氨酶(GOT)(P<0.05)活性;(3)0.9%果寡糖能显著提高21日龄血清钙含量(P<0.05);同时显著降低21日龄和42日龄血清总脂含量(P<0.05).综合分析表明,固始鸡日粮中果寡糖的添加量为0.5%时效果较好.     

饵料不同鱼饲比对黄鳝肝脏、血液生化指标及抗病力的影响

探索饵料中不同鱼饲比对黄鳝肝脏、血液生化指标及抗病力的影响。结果表明,与野生黄鳝组相比,采用冰鲜鱼与膨化饲料投喂的黄鳝,其肝重指数显著高于野生黄鳝组,但试验组组间差异不显著,饵料鱼饲比对黄鳝肝重指数影响不显著;黄鳝血清谷草转氨酶和谷丙转氨酶活性未发现显著性差异,且与野生黄鳝组差异不显著。试验组黄鳝血清甘油三酯含量极显著高于野生黄鳝组,试验组组间差异不显著;随着饵料鱼饲比的降低,血清胆固醇含量有降低的趋势,T(1∶4)组显著低于T(4∶1)、T(2∶1)组 ,而黄鳝抗病力呈显著提高的趋势,T(1∶1)组显著高于T(4∶1)、T(2∶1)组 ,而后2组间无显著性差异。     

益生素对肉鸡免疫器官指数及血液生化指标的影响

探讨发霉日粮添加益生素对内鸡免疫器官指数及血液生化指标的影响.结果表明:在7～21日龄时,益生素组肉鸡血液中谷丙转氨酶活性、谷草转氨酶活性和料重比与发霉组相比,降低显著(P<0.05);与对照组相比,肉鸡血液中性粒细胞数降低显著(P<0.05),浆细胞数提高显著(P<0.05).在22～42日龄时,益生素组肉鸡血液中淋巴细胞数显著高于对照组及发霉组(P<0.05);法氏囊指数与发霉组相比提高显著(P<0.05).     

复合酶对蛋鸡生产性能鸡蛋品质血液生化指标的影响

研究复合酶制剂对蛋鸡产蛋后期生产性能、鸡蛋品质及血液生化指标的影响。结果表明:添加复合酶制剂对产蛋率和料蛋比有一定的改善作用,但对蛋重和鸡蛋品质无显著影响;复合酶制剂3组总蛋白、球蛋白、血磷含量均显著增加(P0.05),各试验组白蛋白和甘油三酯含量均有不同程度的提高,而尿素含量均有不同程度的降低。     

Change in surface chemistry of the cuticle of human hair by chemical and photochemical oxidation

This is a multifaceted study on the characterization and quantification of damage to the hair fiber surface caused by photochemical and cosmetic chemical oxidative processes. Unique techniques were used, including a microfluorometric method that had been adapted to characterize and quantify the delipidation and acidification of the human hair surface during light exposure and cosmetic chemical grooming processes such as bleaching. During photochemical and chemical oxidation, breakdown of the lipid domains (also called the F‐layer) of the outer b‐layer occurs on the exposed scale faces and cysteic acid groups are generated on the cuticle cell surface. The newly formed acid functionalities can be tagged with the cationic fluorochrome Rhodamine B, allowing not only quantification of the level of progressive acidification but also localization of the newly formed acid functionalities. On the other hand, the negative charges generated on the hair surface by oxidation can also bind low molecular weight quaternary cationic conditioning compounds such as cetyltrimethylammonium bromide. This process can be considered a relipidation by adsorption. We have shown that the entire process of delipidation/acid formation and subsequent relipidation by adsorption on the scale faces can be quantified by X‐ray photoelectron spectroscopy. Since X‐ray photoelectron spectroscopy analysis is highly sensitive and able to detect atomic species at the very surface of the hair fibers, receiving signals from an escape depth as shallow as 25 Å, it appeared ideal for the characterization of treatment‐induced changes in the hair surface. However, X‐ray photoelectron spectroscopy provides an average elemental composition of the hair surface including scale faces and scale edges. The microfluorometric technique, on the other hand, can distinguish progressive delipidation of the scale faces from changes occurring at the broken scale edges. This distinction was shown and characterized in detail by slow speed microfluorometric scanning of the hair surface. Chemical and photochemical oxidative processes at the hair surface result in certain collateral effects. Particularly changes in surface wettability and fiber friction are of significance to the cosmetic chemist because they affect the spreading and wicking of products in hair as well as the managability and the body of hair assemblies. Methods of characterizing these effects are discussed briefly.     

Non-destructive and rapid analysis of chemical compositions in Thai steamed pork sausages by near-infrared spectroscopy

The objective of the present study was to evaluate the ability of near-infrared (NIR) spectroscopy to predict chemical compositions of Thai steamed pork sausages in relation to different types of sample presentation forms of NIR measurements (with and without plastic casing). NIR spectra of sausages were scanned to predict the chemical compositions, protein, fat, ash and carbohydrate non-destructively. NIR spectrum features of the sausage samples were strongly influenced by physical properties of the samples, such as the presence of plastic casing and inhomogeneous physical structure inside the samples, yielding significant baseline fluctuations. Thus, regression models were developed using partial least squares (PLS) regressions with two pretreatment methods, namely multiplicative scatter correction (MSC) and second derivative, which overcame the baseline problems. The prediction results suggest that the contents for the protein, fat and moisture can be estimated well with the proper selection of the pretreatment method.     

富硒绿茶对大鼠非酒精性脂肪肝Ca2+-ATPase活性和表达的影响

目的：研究恩施富硒绿茶对大鼠非酒精性脂肪肝病（nonalcoholic fatty liver disease,NAFLD）中肝脏肌浆网/内质网Ca2+-ATPase（sarco（endo）plasmic reticulum Ca2+-ATPase,SERCA）活性及其表达的影响,探讨富硒绿茶防治NAFLD的可能作用机制。方法：将32 只Wistar大鼠分成4 组,分别饲喂标准饲料＋常规饮水（NC组）、高脂饲料＋常规饮水（HC组）、高脂饲料＋普通绿茶（TC组）、高脂饲料＋富硒绿茶（SeC组）。9 周后处死,观察大鼠一般情况,测定肝细胞内Ca2+含量、肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）水平、肝脏组织ATPase活性;采用免疫组化染色和Western blotting检测肝脏内总SERCA蛋白表达,观察各指标变化情况。结果：HC组大鼠肝细胞内Ca2+含量明显增高,Na+-K+-ATPase、Ca2+-ATPase活性降低,SERCA蛋白表达降低;富硒绿茶干预后Ca2+含量降低,酶活性升高,表达增加,较普通绿茶效果明显。结论：富硒绿茶对高脂饮食诱导的大鼠非酒精性脂肪肝病具有干预作用,可能是通过降低肝细胞内Ca2+和TNF-α含量而改善肝脏能量代谢障碍,同时提高了SERCA活性,增强其蛋白表达而实现的。     

Changes in the volatile compounds and chemical and physical properties of Yali pear (Pyrus bertschneideri Reld) during storage

Volatiles from stored Yali pear (Pyrus bertschneideri Reld) were studied using high-resolution gas chromatography and the solid-phase microextraction (SPME) method of gas chromatography/mass spectrometry (GC/MS). The dominant components were ethyl butanoate, ethyl hexanoate, α-farnesene, hexanal, ethyl acetate, hexyl acetate, ethanol and so on. By using GC-olfactometry, it was demonstrated that the volatile compounds from SPME were responsible for the aroma of Yali pear. The levels of sugars, organic acids, and phenolic acids in Yali pear were investigated using high-performance liquid chromatography. Fructose was the dominant sugar, followed by glucose and sucrose. With increasing storage time, sucrose levels decreased, however fructose and glucose levels did not changed remarkably. There was a slight decrease in flesh firmness during storage. The general soluble solids concentration, slightly decreased after 5 months storage. Some aroma volatile components increased during storage, while others decreased, especially the esters. The organic acids and phenolic acids also changed. Yali pear flavor was affected by changes in the levels of volatile compounds, and chemical and physical properties.     

欧李发酵液对高脂血症SD大鼠血脂的调控及对肝脏的保护作用

研究欧李发酵液(Cerasus humilis fermentation juice,CF)对高脂血症SD大鼠血脂的调控作用及肝保护作用.健康雄性SD 大鼠30 只,适应性喂养7 d后,依据体重随机分为对照组、高脂模型组与CF 组(发酵液浓度为40％,灌胃剂量为10 mL/kgbw),每组10只,经口灌胃,1次/d,连...     

糖醋排骨中羧甲基赖氨酸分析方法的建立及其烹饪过程中动态变化

采用高效液相色谱-三重四极杆质谱联用技术建立了一种操作简单、稳定性好的检测中式菜肴糖醋排骨中羧甲基赖氨酸（Nε-(carboxymethyl)lysine,CML）的方法。样品用正己烷去脂肪,硼氢化钠还原,盐酸水解蛋白,Oasis MCX固相萃取小柱净化。以5 mmol/L的乙酸铵溶液和甲醇-水（80∶20,V/V）溶液作为流动相,采用Phenomenex Synergi 4 μ Hydro-RP 80A色谱柱,在正离子模式下采用多重反应监测分析,同位素内标法定量。该方法检出限为1.40 μg/g,加标回收率为90.94%～105.26%,相对标准偏差为5.80%～15.46%。采用该分析方法对中式菜肴糖醋排骨加工过程中CML的含量变化进行分析,结果表明,加工温度和加热时间以及糖和油脂的添加均可以显著影响糖醋排骨中CML的含量。     

基于UPLC-Orbitrap-HRMS技术的苎麻籽乙醇提取物中主要化学成分分析与鉴定

应用超高效液相色谱-离子阱-超高分辨率质谱技术对苎麻籽乙醇提取物主要化学成分进行了分析与鉴定.高效液相色谱条件为Agilent 5TC-C18色谱柱(4.6 mm×250 mm,5μm)、0.2％甲酸水溶液-乙腈作为流动相梯度洗脱.质谱条件为电喷雾离子源(ESI),离子阱质量分析器(orbitrap),喷雾电压3500...     

Identification of the key odorants in raw French beans and changes during cooking

 By application of aroma extract dilution analysis (AEDA) to an extract prepared from raw French beans, 25 odour-active compounds with flavour dilution (FD) factors in the range 4–2048 were detected and subsequently identified. Among them, (Z)-3-hexenal (green, leaf-like), 1-octene-3-one (mushroom-like), 3-isobutyl-2-methoxypyrazine (earthy, beany) and (E,Z)-2,6-nonadienal (cucumber-like) showed the highest FD factors. In an extract prepared from the same amount of cooked beans, 3-isobutyl-2-methoxypyrazine was identified as the most potent odorant, followed by 1,5-(Z)-octadiene-3-one (geranium-like), 3-isopropyl-2-methoxypyrazine (earthy, beany), 3-(methylthio)propanal (methional; cooked potato), 4,5-epoxy-(E)-2-decenal (metallic) and an unknown compound (FD 256) with a smell of geranium leaves. A decrease in (Z)-3-hexenal and 1-pentene-3-one (etheral, pungent) and an increase in methional during cooking were shown to be mainly responsible for the flavour changes induced by cooking the beans. Received: 22 January 1998 / Revised version: 16 March 1998     

HS-SPME结合GC-MS分析麻辣火锅底料炒制和熬煮过程中挥发性物质的变化

为了研究火锅风味的变化以及为探究火锅底料开发利用及质量控制、使用安全性提供科学依据,本实验采用顶空固相微萃取结合气相色谱-质谱联用法探究麻辣火锅底料炒制和熬煮过程中的挥发性物质。结果表明:火锅底料炒制和熬煮过程中分别检测到53、50种挥发性物质,从实验的7个样本来看,其相对含量由高到低分别是醇类物质、烯类物质、醛类物质、酸及酯类物质和酮类物质等。火锅底料加工过程中,醇类物质相对含量随着炒制时间延长而增多,而熬煮过程受到汤底影响其相对含量下降后逐渐回升。未加工前烯类物质的相对含量最高,加工后含量下降。醛类物质的相对含量与熬煮时间呈正相关,可能与火锅底料的特征香气有关。加工时间越长,酸及酯类物质相对含量越低。研究还发现,随着加工时间延长,火锅底料中醚类、苯类等物质大量出现,可能会影响火锅底料食用的安全性,其机理有待进一步研究。