苦荞螺旋藻复合片调节血糖人体试食研究

目的:研究苦荞螺旋藻复合片生产工艺和观察其对人体血糖的影响。方法:参照保健食品辅助降血糖功能学评价方法,对Ⅱ型糖尿病病人连续试食40d和60d后,测定相应指标。结果:试食40d后糖尿病临床症状有明显改善,总有效率均在85%以上,但病人多食易饥、倦怠乏力、多尿三项临床指标在统计学无显著性差异,仅有口渴多饮临床指标有显著性差异(p<0.05)。空腹血糖、餐后2h血糖无显著性差异;试食60d后糖尿病临床症状、空腹血糖、餐后2h血糖均有显著性差异。结论:苦荞螺旋藻营养复合片具有明显的辅助调节血糖的功能。     

鲜奶中蛋白质含量的快速测定

目的建立一种鲜奶中蛋白质含量快速消化的简便测定方法。方法改用8.8mol/L过氧化氢,浓硫酸混合液(4:1,V:V)为消化试剂,消化好的试样以甲醛法测定。结果该方法的消化时间由原来的6h缩至30min,测定结果和凯氏定氮法(国家标准方法)的测定结果无显著性差异。结论该方法分析速度快,操作简便,可用于鲜奶中蛋白质的测定。     

低温保活运输对海鲈鱼应激及品质的影响

以海鲈鱼为研究对象,探讨低温保活运输对其血液生化和肌肉理化指标的影响。首先分别测定温度、盐度、密度和暂养时间对海鲈鱼运输存活率的影响;其次,将海鲈鱼以3 ℃/h的降温速率降温至保活运输温度12,16 ℃和20 ℃,以室温下不运输的海鲈鱼为对照组,分别在模拟运输第12,24,36,48,60,72 h和运输结束恢复12 h后测定水质、血液生化和肌肉理化指标。结果表明:在温度12 ℃、盐度16‰、鱼水比1 ∶ 10~1 ∶ 8、暂养时间36 h条件下,保活运输后海鲈鱼的存活率最高。在整个保活运输过程中,水质随温度的升高呈显著下降趋势(P＜0.05)。血清乳酸脱氢酶、谷草转氨酶和谷丙转氨酶活性以及皮质醇水平显著升高(P＜0.05),血糖和应激蛋白呈先升高后降低的趋势。运输结束恢复12 h后, 12 ℃组海鲈鱼应激蛋白、乳酸脱氢酶、谷草转氨酶和谷丙转氨酶活性恢复至对照组状态。肌肉中总蛋白和乳酸水平呈显著上升趋势, 肌糖原、硬度和咀嚼性显著降低(P＜0.05),保活运输前、后海鲈鱼肌肉pH值、持水力和弹性无显著性变化(P＞0.05)。海鲈鱼长途运输的最佳保活温度为12 ℃。该研究结果为海鲈鱼及其它海水鱼类的保活运输提供参考。     

鲜罗汉果素血糖生成指数(GI)的研究

研究了鲜罗汉果素的血糖生成指数。将昆明小鼠20只随机分为对照组、实验组各10只,各组小鼠给药剂量为6.5g/kg,给药容量为20mL/kg,一次性灌胃,对照组给予葡萄糖、实验组给予鲜罗汉果素,并分别于灌胃后30、60、90、120min,采血、分离血清,测定并计算血糖值。结果表明:葡萄糖2h内血糖最高值与最低值呈现非常显著性差异(p<0.01),但鲜罗汉果素无显著性差异,鲜罗汉果素GI值为32.94。由此可见,鲜罗汉果素具有餐后血糖生成低、血糖保持稳定的特点,有助于维持餐后血糖稳定。     

Folin-Ciocalteu法测定鱼腥草多酚的含量

目的：探索优化Folin-Ciocalteu 法测定鱼腥草中多酚含量。方法：运用不同的溶剂超声提取鱼腥草叶片,比较不同时间提取物用Folin-Ciocalteu 法测得的吸光度。并以乙醇2h 提取液为对象研究不同的碳酸钠溶液、Folin-Ciocalteu 显色剂加入量、反应温度及时间对吸光度大小及稳定性的影响。结果：甲醇提取效率最高,其次为乙醇、丙酮和水;提取时间2h;较适宜测定方法为采用0.5mL 提取液,加入2.0mL 20% 的碳酸钠缓冲液、1.5mLFolin-Ciocalteu 显色剂,蒸馏水定容至50.0mL,55℃保温1.5h,测定波长为760nm。结论：该方法比较快速、准确和稳定,适合推广。     

膨化米饼生产工艺研究

对膨化米饼生产工艺和加工过程的主要参数进行研究,为膨化米饼生产提供参数。结果 表明:原料配比、米坯的干燥温度、干燥时间对膨化米饼感官品质有显著影响;将稻米凝 胶强度控制在200 g/10 mm左右,干燥米坯含水量控制在9％～11％时,产品质量较好。 适宜工艺参数为:原料配比1:20(小麦淀粉:粳米),于50℃第一次干燥12 h,室温静置 24 h,再于50℃第二次干燥10 h。     

择期手术患者缩短术前禁食禁饮时间的研究

目的:对缩短择期手术患者术前禁食禁水时间进行研究,探讨其可行性。方法:选择2017年2月-2018年2月来我院治疗的200例择期手术患者作为研究对象,按照随机的原则进行分组,实验组100例,对照组100例,对实验组患者术前禁食6-8h、禁水2-3h,对照组术前禁食12h、禁水6h。结果:将两组患者在术前的口渴、饥饿、烦躁、疲乏无力等情况进行观察比较,观察组出现不良症状的患者人数明显少于对照组,差异显著(P0.001);另外,将两组患者术中出现的不良反应进行对比,比如术中误吸、术后恶心、呕吐等,数据显示两组无明显差异(P0.05)。结论:对择期手术患者在术前禁食6-8h,禁水2-3h,可以减少患者术前的不良症状,并且对术中的不良反应无明显影响,具有可行性,可以临床推广使用。     

燕麦β-葡聚糖对高脂血症大鼠空腹和餐后脂代谢的影响

研究了燕麦β-葡聚糖对高脂血症大鼠空腹和餐后脂代谢的影响.58只雄性SD大鼠随机分为基础组(n=10)和模型组(n=40),分别饲喂基础饲料和高脂饲料,饲养3w后,将造模成功的高血脂症大鼠随机分为高脂对照组、添加燕麦β-葡聚糖低剂量组、中剂量组和高剂量组,每组10只,分别饲喂含0、6、12、24g β-葡聚糖/kg的高脂饲料6w.于实验期末,分别测定大鼠空腹(禁食12h)和餐后(禁食16h后再强饲5g饲料后2h)血浆TC、TG、LDL-C、HDL-C、ApoAI和ApoB的含量以及肝脏脂质变化.结果表明:不同剂最β-葡聚糖都极显著降低空腹血浆TC、LDL-C和ApoB水平,而对HDL-C、TG和ApoAI无显著影响;β-葡聚糖可以改善餐后血脂分布,降低肝脏脂质含量,不同剂量之间具有一定的差异性.     

黑米黑木耳粉对代谢综合征患者糖脂代谢的影响

目的:探讨食用黑米黑木耳粉(一种新型复合杂粮)对代谢综合征患者血糖血脂的影响。方法:60名代谢综合征患者随机分为黑米黑木耳粉组和普通糙米组,实验时间1个月。研究期间登记受试者饮食情况。研究开始前和干预1个月后进行血液生化、维生素浓度和人体成分测定,其中血糖测定分别选择空腹、餐后0.5、1和2h等4个时间点,血脂测定选择空腹和餐后2h等2个时间点。结果:4例患者退出研究,获得有效数据56例,其中黑米黑木耳组27例、普通糙米组29例。研究前后2组身高、体重、BMI、血糖、总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、甘油三酯、维生素浓度均无统计学意义。实验结束后与普通糙米组比较,黑米黑木耳组代谢综合征患者空腹血糖、LDL-C、餐后2h甘油三酯明显降低,有显著性差异(P0.05);黑米黑木耳组维生素B9(叶酸)浓度高于普通糙米组,黑米黑木耳组维生素B1、维生素B9浓度亦明显高于实验前(P0.05)。结论:食用黑米黑木耳粉,可以降低代谢综合征患者空腹血糖、低密度脂蛋白胆固醇及餐后甘油三酯,可作为代谢综合征的主食选用。     

制备L-亮氨酸螯合钙的新工艺及其生物利用度的研究

采用单因子静态实验,考察了温度、NaOH和亮氨酸的摩尔比、L-亮氨酸浓度、树脂量对利用离子交换法制备L-亮氨酸螯合钙新工艺的影响,并测定了25℃下的离子交换动力学曲线。结果表明:交换可在室温下进行;NaOH与亮氨酸适宜的摩尔比1:1～1.3:1;L-亮氨酸浓度应控制在0.3 mol/L以下;适宜的树脂用量应满足树脂中钙与溶液中亮氨酸的摩尔比1:2;交换平衡时间为15 min。根据最佳工艺条件设计制备L-亮氨酸螯合钙的新工艺流程。采用小鼠对L-亮氨酸螯合钙和葡萄糖酸钙进行药动学和药效学实验对比,结果表明:L-亮氨酸钙的生物利用度比葡萄糖酸钙要高,其相对生物利用度是葡萄糖酸钙的175.3%,并具有缓释、药效时间长、不需要消耗胃酸等特点;L-亮氨酸螯合钙能显著性增加大鼠股骨重量,饲料中添加兼有促进小鼠体重增长的作用。     

牦牛血理化特性的研究

为开发青海牦牛血资源,本文对牦牛血的一些加工和保藏特性进行了研究。结果表明牦牛血在重力沉降时,上层血浆析出量和时间呈正相关的线性关系。沉降72h,血浆沉降全血总量的50%,所以不宜采取重力沉降的方法分离。对牦牛全血、血浆和血细胞的水分、灰分、蛋白含量进行了分析。全血、血浆和血细胞的蛋白质含量分别为15.5±0.8%、6.9±0.7%、32.7±0.9%。牦牛血在12℃和25℃贮藏时,分别在第72h和12h开始腐败。牦牛全血、血细胞、血浆的突变温度分别为70℃、68℃、72℃,不适于高温加热杀菌。     

鲜马铃薯直接生产茁霉多糖中试工艺研究

在茁霉多糖小试生产工艺的基础上设计了5L中试生产工艺方案,分别研究了接种量和转速对中试发酵的影响,对比研究了中试和小试发酵液在生物量、多糖产量、蛋白含量及色素等各项指标上的差异,结果表明:接种量对中试发酵有一定影响,其中以12%的接种量效果较好;与小试发酵不同,中试发酵在搅拌速度上应采用变速搅拌方式,即前期发酵采用160r.min-1较低搅拌速度,在后期发酵时应采用200r.min-1的搅拌速度;两种发酵方式比较,在相同的发酵时间内,生物量和多糖产量两项指标,中试发酵均高于小试发酵,而蛋白质和色素产量较小试发酵低,确定的中试工艺条件为:装液量3.5L,接种量12%,初始pH6.5,温度30℃,发酵时间5d,在此工艺下制得的发酵液中多糖含量达到3.66g/L。     

Carbohydrate supplements and their effects on pasture dry matter intake,feeding behavior,and blood factors associated with intake regulation

Supplementary feeds are offered to grazing dairy cows to increase dry matter (DM) and metabolizable energy (ME) intakes; however, offering feed supplements reduces pasture DM intake, a phenomenon known as substitution. The objective of the study was to investigate changes in blood factors associated with intake regulation in monogastric species in pasture-fed dairy cows supplemented with either a starch- or nonforage fiber-based concentrate. Fifteen multiparous Friesian × Jersey cross cows were assigned to 1 of 3 treatments at calving. Measurements were undertaken in wk 8 of lactation. Treatments were pasture only, pasture plus a starch-based concentrate (3.5 kg of DM/cow per day; STA), and pasture plus a nonforage fiber-based concentrate (4.4 kg of DM/cow per day). Pelleted concentrates were fed at an isoenergetic rate in 2 equal portions at a.m. and p.m. milkings. Measurements were undertaken to investigate differences in pasture DM intake, feeding behavior, and profiles of blood factors for 4 h after a.m. and p.m. milkings, the periods of intensive feeding in grazing cows. Supplementing cows with STA concentrate reduced pasture DM intake to a greater extent than the fiber concentrate, although time spent eating did not differ between treatments. The blood factor response to feeding differed between the a.m. and p.m. feeding events. Blood factors associated with a preprandial or fasted state were elevated prefeeding in the a.m. and declined following feeding, whereas satiety factors increased. In comparison, the blood factor response to feeding in the p.m. differed, with responses to feeding delayed for most factors. Plasma ghrelin concentration increased during the p.m. feeding event, despite the consumption of feed and the positive energy state remaining from the previous a.m. feeding, indicating that environmental factors (e.g., sunset) supersede physiological cues in regulating feeding behavior. The greater reduction in pasture DM intake for the STA treatment in the p.m. may be related to the level of hunger or satiety before the feeding event and not solely to the consumption of supplement. Data indicate that neuroendocrine factors are, at least in part, responsible for the substitution of pasture for supplementary feeds.     

低分子量壳寡糖改善II型糖尿病大鼠症状及其作用机制研究

目的:探讨不同分子量壳寡糖对糖尿病大鼠的降糖机制。方法:Wistar大鼠采用高脂高糖饮食同时腹腔注射链脲佐菌素复制II型糖尿病大鼠模型。将动物随机分为正常对照组、模型组、阳性对照和药物治疗组。四周后处死大鼠取血清测定血糖、果糖胺;取新鲜肝脏测定肝糖原、SOD、MDA。结果:与正常组比较,模型组血糖、果糖胺水平明显升高(p<0.01),肝糖元含量明显降低(p<0.05)。与模型组比较,治疗组各项指标有明显改善(p<0.05),且这种作用具有剂量和分子量依赖性。结论:本模型大鼠血糖升高,并引起自由基代谢紊乱,分子量1700的壳寡糖、大鼠日用剂量为140mg/kg适合高脂糖尿病患者,可降低血糖、提高抗氧化能力起到保健作用。     

复合型主食早餐对2型糖尿病患者血糖影响的研究

目的:探讨一种新的复合型主食早餐对2型糖尿病患者血糖的影响。方法:选取60例新入院2型DM患者,实验组20例,对照组40例。实验组给予复合馒头和多元豆浆组成的复合型主食糖尿病早餐,对照组给予标准粉馒头为主食糖尿病早餐。比较两组病人干预前后空腹血糖值和餐后2h血糖值以及平均住院天数等。结果:两组营养治疗后与营养治疗前相比,空腹血糖和餐后2h血糖值均有明显降低(p<0.05);实验组与对照组相比,餐后2h血糖值变化有显著性差异(p<0.05);两组平均住院天数无明显差异(p>0.05)。结论:复合型主食糖尿病早餐对2型DM患者餐后血糖控制有益。     

Development of a rapid method for the measurement of lactose in milk using a blood glucose biosensor

Current methods for lactose measurement in dairy products are time consuming and tedious and may require expensive equipment and skilled technicians. The aim of this research was to develop a novel and rapid method for the routine measurement of lactose in dairy products. The proposed method is based on the rapid hydrolysis of lactose using β-galactosidase and subsequently measuring glucose using a blood glucose meter. Blood glucose meters were developed after decades of research and clinical trials and are used extensively worldwide by individuals with diabetes to monitor their blood glucose levels. The method was developed and validated in a series of experiments. In the first experiment, temperature and time required for the near-complete hydrolysis of lactose were determined. Subsequently, the influence of glucose meters and their test strip lots were evaluated. We found that meters were not significantly different. However, the test strip lots were significantly different from each other. In the second experiment, the proposed method was validated using different concentrations of lactose solutions (1.9–6.5%) and compared with a HPLC-based reference method. In the third experiment, the proposed method was used to determine the lactose content of raw milk. The proposed method shows potential for rapid, routine, and low-cost measurement of lactose in milk and other dairy products.     

佛手山药多糖对2型糖尿病大鼠糖脂代谢及氧化应激的影响

目的:探讨佛手山药多糖对实验性2型糖尿病大鼠糖脂代谢及体内氧化应激的影响。方法:SD大鼠高脂饲料喂养,结合小剂量腹腔注射链脲佐菌素40 mg/kg建立糖尿病大鼠模型,成模大鼠随机分为模型组、阳性对照组(二甲双胍150 mg/(kg·d))和佛手山药多糖组(400 mg/(kg·d)),并设正常组。观察给药期间各组体质量及血糖变化,给药6周后摘眼球取血,检测甘油三酯(triacylglyceride,TG)、胆固醇(total cholesterol,TC)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、丙二醛(malonaldehyde,MDA)、一氧化氮(NO)含量及超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力,并解剖称取新鲜肝脏,测定肝糖原含量。结果:与模型组比较,佛手山药多糖能有效缓解糖尿病大鼠的症状,能明显降低实验性2型糖尿病大鼠空腹血糖水平(P0.05),对TC和LDL-C含量有极显著的降低作用(P0.01),对TG含量有显著降低作用(P0.05),能显著增加SOD和CAT的活力,而对肝糖原,HDL-C、MDA、NO含量及GSH-Px的活力无显著影响。结论:佛手山药多糖对实验性2型糖尿病大鼠有降低血糖作用,对血脂代谢紊乱有一定的调节作用,其降糖和降脂的具体机制可能与提高机体SOD、CAT活性相关。     

Mammary blood flow and regulation of substrate supply for milk synthesis

In ruminants, mammary supply of substrate varies with rate of mammary blood flow and concentrations of blood substrates. Blood concentrations of most mammary substrates, except acetate and tryptophan, do not vary greatly with feed intake, short term. Fasting reduces mammary blood flow, whereas milking and injection of growth hormone or thyroxine increase flow. It is proposed that the fraction of cardiac output that perfuses the udder of lactating ruminants plays a role in regulation of nutrient partitioning between milk and body tissues. In fed animals this fraction is 15 to 16% of cardiac output, which declines on fasting to 8 to 9% and increases slightly following growth hormone treatment to 17.6%. Following realimentation of fasted cows or goats, mammary blood flow takes several hours to return to normal. Investigation of the mechanism of this response, in terms of the ability of the animal to recognize its nutritional status and partition nutrients accordingly, should prove fruitful to understanding causes of variations of milk production in response to feed quantity and quality. Several substrates show increased mammary arteriovenous difference with increasing blood concentrations. This may reflect differing ratios of blood flow:milk yield. The steep gradient of concentration of substrates across the mammary epithelial cell membrane suggests that a major impediment to substrate supply for milk synthesis is the rate of substrate transport across the membrane.     

A rapid HPLC post-column reaction analysis for the quantification of ergothioneine in edible mushrooms and in animals fed a diet supplemented with extracts from the processing waste of cultivated mushrooms

For establishing an efficient and sensitive method for the quantitative determination of 2-thiol-l-histidine-betaine (ergothioneine, ERG) in edible mushrooms and the blood and muscles of animals, a technique using reversed-phase separation and post-column reaction between 2′-dipyridyl disulphide and ERG was developed. A corresponding derivative 2-thiopyridone, detected at 343 nm, was used for estimating ERG concentration. The flow rate, temperature, pH, and composition of the solution were optimised. A low limit of quantification (1.41 ppm) and a simpler sample preparation made this technique more rapid compared to other methods using liquid chromatography–mass spectrometry. The coefficient of variation (CV) values for the reproducibility and recovery of ERG were within the acceptable values of 6% and 97.5–100.0%, respectively. The efficiency of this methodology was compared with that of spectrophotometric and mass-spectrometric quantitative methods, and was assessed in the light of previous studies. The ERG contents in different mushrooms were 12.69–234.85 mg/kg wet weight basis. Dietary supplementation with extracts from mushroom processing waste significantly improved ERG bioavailability in the blood of yellowtail fish and muscle tissue of cattle.     

Studies of the changes in edible fats during heating and frying

For detecting the changes in edible fats during the frying operation and for quality assessment of used frying fats 5 relatively simple methods were proposed: determination of polymer content by gel permeation chromatography, measurement of total polar artefacts by TLC followed by densitometry or by adsorption column chromatography, determination of decrease in essential fatty acid concentration and photometric measurement of absorbance at 232 nm. Using the above methods degradation of sunflower oil, rapeseed oil and lard was investigated by running 12 laboratory experiments with different heating or frying conditions. The results showed that both the composition of fat and the frying parameters greatly influence the rate of deterioration. Study of relationships between values obtained by different methods (using data from 110 samples) indicated that high, linear correlations depending on the nature of fat can be found. Correlation coefficients and equations of regression lines were calculated.