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糖醇食品健康营养新概念 总被引:1,自引:0,他引:1
糖醇具有热量低、不刺激胰岛素分泌、能缓解糖尿病、防止肥胖和预防龋齿等功能特性,是一种健康营养的食糖替代品.介绍了各种糖醇的物理化学性质、生理功能与特性,并阐述了糖醇在食品工业中的应用及前景. 相似文献
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异麦芽酮糖(又称“帕拉金糖”)是由1分子葡萄糖和1分子果糖以α-1,6糖苷键连接形成的还原型二糖,将异麦芽酮糖氢化还原后可以制得异麦芽酮糖醇(又称“帕拉金糖醇”),是国际上新兴的功能性食用糖醇。异麦芽酮糖醇是1种包含2种立体异构体即α-D-吡喃葡萄糖基-(1,6)-D-山梨醇(GPS)和α-D-吡喃葡萄糖基-(1,1)-D-甘露醇二水合物(GPM)的白色晶状混合物。根据GPS和GPM比例的不同,主要有ISOMALT ST、ISOMALT GS、ISOMALT DC和ISOMALT LM 4种不同的产品。异麦芽酮糖醇是迄今为止唯一完全由蔗糖衍生获得的二元糖醇,其口感近似于蔗糖,甜度约为蔗糖的45%,热值为蔗糖的50%,具有化学性质稳定、不致龋齿、摄取后不会导致血糖和胰岛素水平波动等优点,可以作为蔗糖的健康替代品。对异麦芽酮糖醇的生理功能、工业制造及应用现状进行了梳理,系统介绍了异麦芽酮糖醇的制造工艺路线(生物催化法和加氢还原技术),并重点介绍了异麦芽酮糖醇生物合成过程的关键酶——蔗糖异构酶的结构、催化机理和分子改造等方面的研究进展,以期为相关研究工作的开展和工业化生产提供指导。 相似文献
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稀有糖是指在自然界中存在但含量极少的一类单糖及糖醇、环醇、去氧糖、氨基糖、分支碳链糖等衍生物,在膳食、医疗、保健、等领域中有着重要的作用和巨大的市场潜力。综述了稀有单糖及相应糖醇的C-2差向异构化、C-3差向异构化、氧化还原、糖的递增/递降反应等合成途径。详细阐述了以D-塔格糖3-差向异构酶(DTE)为核心,结合醛糖还原酶、醛糖异构酶、多元醇脱氢酶(polyol dehydrogenase,PDH),进行所有同碳糖及相应糖醇之间的相互转化的Izumoring生物合成策略。在此基础上结合碳的递增反应(Kiliani氰化增碳法)、碳的递降反应(Wohl递降法、Ruff递降法)等生化合成方法,初步形成了丁糖、戊糖、己糖及相应糖醇之间的相关转化策略。阐述了稀有单糖及相应糖醇合成策略的研究意义,并对稀有糖合成的研究趋势进行了展望。 相似文献
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采用高效液相-蒸发光散射检测器(HPLC-ELSD)法对4种糖醇(赤藓糖醇、木糖醇、山梨醇、麦芽糖醇)进行了同时检测分析并研究了其热稳定性。较佳的检测条件为Amide 80亲水柱,流量0.2 mL/min,柱温33℃,ELSD漂移管温度50℃,载气流量2.5 L/min。结果表明,4种糖醇的进样量在0.025~1.000 mg/mL范围内,线性关系良好.赤藓糖醇、木糖醇、山梨醇、麦芽糖醇的检测限分别为14.1、33.0、19.5、15.3μg/mL,精密度(相对标准偏差RSD)分别为1.55%、1.23%、1.30%、1.49%。在不同加热温度和加热时间下,4种糖醇的热稳定性具有如下规律:木糖醇赤藓糖醇山梨醇麦芽糖醇。 相似文献
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Cornelis Verduyn Guido J. Breedveld W. Alexander Scheffers Johnnes P. Van Dijken 《Yeast (Chichester, England)》1988,4(2):143-148
The substrate specificity of alcohol dehydrogenase (ADH) from Hansenula polymorpha and Candida utilis has been compared with that of the classical ADH from baker's yeast. Cell-free extracts of H. polymorpha and C. utilis exhibited a much higher ratio of butanol to ethanol oxidation than baker's yeast ADH. This was also observed with the purified enzymes. The ratio of activities with ethanol and butanol was pH-dependent. With the baker's yeast enzyme the activity strongly decreased with increasing chain length, whereas the enzymes form H. polymorpha and C. utilis showed a high reactivity with long-chain alcohols. In addition, the affinity constant for ethanol was more than tenfold lower than that of the baker's yeast enzyme. The purified preparation yielded several protein bands on polyacrylamide slab gels, each of which showed activity with both ethanol and butanol. 相似文献
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乙醛脱氢酶和乙醇脱氢酶是嗜热厌氧乙醇菌Thermoanaerobacter ethanolicus乙醇代谢途径中的关键酶。根据高同源性的NADP(H)依赖型Ⅱ型乙醇脱氢酶(S-ADH)的序列设计引物,从T.ethanolicusJW200基因组中PCR扩增出编码S-ADH的基因,插入带组氨酸标签的pET-20(b),测序获得基因大小为1 059 bp,并在大肠杆菌JM109(DE3)中表达。表达产物经Ni亲和柱提纯达电泳纯。带组氨酸标签的重组NADP(H)依赖型乙醇脱氢酶具乙醇脱氢酶和乙醛脱氢酶双活性,能将乙酰辅酶A转化成乙醇.带组氨酸标签的重组酶酶学性质为乙醛脱氢酶活性最适值为pH 8.4,最适温度70℃;乙醇脱氢酶活性正、逆反应分别最适pH 8.0,最适T 55℃;最适pH8.9,最适为T 60℃。以乙酰辅酶A(Aceyl-CoA)为底物,该酶的Km为3.32 mmol/L,Vmax为12.5μmol/(min.mg)。T.ethanolicusJW200中双活性S-ADH的首次发现,建立了该菌乙醇代谢途径中从乙酰辅酶A到的乙醇的另一条通路。 相似文献
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In this study, we investigated the beneficial effects of Lactococcus chungangensis CAU 28, a bacterial strain of nondairy origin, on alcohol metabolism in rats treated with ethanol, focusing on alcohol elimination and prevention of damage and comparing the effects with those observed for Lactococcus lactis ssp. lactis ATCC 19435. Male Sprague-Dawley rats were orally administered 20% ethanol and 3 substrates (freeze-dried cells, cream cheese, and yogurt) containing Lc. chungangensis CAU 28 or Lc. lactis ssp. lactis ATCC 19435, which were provided 1 h before or 1 h after ethanol ingestion. Blood samples were collected from the tail veins of the rats at 1, 3, 6, 12, and 24 h after ingestion of ethanol, Lc. chungangensis CAU 28 substrate, or Lc. lactis ssp. lactis ATCC 19435 substrate. Alcohol and acetaldehyde concentrations in the Lc. chungangensis CAU 28 substrate-treated rats were significantly reduced in a time-dependent manner compared with those in the Lc. lactis ssp. lactis ATCC 19435 substrate-treated rats. Among the experimental groups, treatment with cream cheese before ingestion of 20% ethanol was found to be the most effective method for reducing both alcohol and acetaldehyde levels in the blood. Alanine aminotransferase and aspartate aminotransferase activities in the Lc. chungangensis CAU 28 substrate-treated rats were significantly lower than those in the positive controls. Moreover, in the Lc. chungangensis CAU 28 cream cheese-treated group, rats showed a reduction of liver enzymes by up to 60%, with good effectiveness observed for both pre- and post-ethanol ingestion. These results suggested that intake of lactic acid bacteria, particularly in Lc. chungangensis CAU 28-supplemented dairy products, may reduce blood alcohol and acetaldehyde concentrations, thereby mitigating acute alcohol-induced hepatotoxicity by altering alcohol-metabolizing enzyme activities. 相似文献
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目前产L-乳酸的米根霉菌株的最适发酵温度为32℃,该温度较低,不利于产物分离且易染杂菌。以米根霉As3.819为出发菌株,采用60Co-γ射线进行诱变处理,以正突变率为指标,诱变剂量为400Gy,通过筛选得到耐38℃高温的5号突变株mut-5,经连续传代7次,遗传性状稳定。与出发菌株相比,发酵72h后,mut-5突变株发酵液中的乳酸含量提高了24.15%,乙醇含量降低了9.27%。乳酸脱氢酶(LDH)比活力提高了39.41%,乙醇脱氢酶(ADH)比活力有所下降,而对还原糖的利用速率以及生物量的积累均高于出发菌株。 相似文献
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CRISPR/Cas9是一个简单、高效的用于靶向目的基因和无标记的基因组工程的工具。本文通过构建酿酒酵母沉默组件PGK-SGPD1-CYC1,使甘油-3-磷酸脱氢酶I(Glycerol-3-phosphate dehydrogenase,GPD1)基因在PGK强启动子、CYC1终止子在特定区域内进行干扰和表达。应用CRISPR/Cas9基因编辑技术,在中断乙醇脱氢酶Ⅱ(alcohol dehydrogenase Ⅱ,ADH2)基因的同时,定点敲入GPD1基因的反义干扰组件,从而特定地干扰GPD1的表达。采用高效的酵母化学转化法将反应组件敲入酿酒酵母Y1H中,CRISPR/Cas9介导的同源重组效率达43.48%,由此获得了ADH2基因中断和GPD1反义干扰的酿酒酵母突变株。发酵实验结果表明,酿酒酵母突变菌株SG1-1与出发菌株Y1H相比,乙醇产率提高了9.07%,甘油产率下降了12.05%,乙酸产率下降了12.30%,结果表明通过中断ADH2基因及插入GPD1反义干扰组件,既能够中断ADH2基因的功能,减少乙醇转化为乙醛,同时也能在一定程度上干扰GPD1基因的表达,提高乙醇产率。 相似文献
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目的 探究表没食子儿茶素没食子酸酯(epigallocatechingallate,EGCG)与L-茶氨酸对乙醇脱氢酶(alcohol dehydrogenase, ADH)和乙醛脱氢酶(acetaldehyde dehydrogenase, ALDH)活性的体外协同作用。方法 设置不同浓度及组分,以0μg/mL实验组为对照,先后进行单因素实验和最优组合验证实验,通过对ADH、ALDH活性的检测,确认EGCG、L-茶氨酸不同剂量的解酒效果并探究其最佳配比。结果 单因素实验中,样品质量浓度为200、300μg/mL实验组相较于0μg/mL浓度组,随着EGCG和L-茶氨酸的添加, ADH和ALDH活性显著高于空白组(P<0.05);最优组合验证实验中,11组不同配比组合物对ADH和ALDH活性均具有促进作用,且协同组比单因素组激活效果要更好。其中,当配比组合物为7:3时, ADH、ALDH的活性最高。结论 EGCG、L-茶氨酸解酒组合物最佳配比为7:3时ADH与ALDH活性最高,研究结果为EGCG、L-茶氨酸组合物用于抗醉酒药物研发提供科学依据。 相似文献
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Water soluble propolis was prepared using β–cyclodextrin, and its effect on an ethanol-induced hangover was examined in Sprague–Dawley (SD) rats fed with ethanol. When SD rats were administrated with propolis 30 min after ethanol feeding, ethanol content in the rat serum decreased 2.1 times 1 h after ethanol feeding. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in rat liver increased 3.0 and 4.4 times, respectively, 1 h after ethanol feeding and administration of propolis 30 min after ethanol feeding. There were no differences in the expression of ADH and ALDH genes regardless of propolis administration. These results indicated that a decrease in ethanol content in the serum was not due to an increase in the expression of ADH or ALDH genes but rather, an increase in activities of ADH and ALDH. 相似文献
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为了寻找代替化学防腐剂的绿色安全天然添加剂,研究了丁香酚对金黄色葡萄球菌的抑菌作用。以丁香酚为原材料,采用96孔板微量稀释法和琼脂平板稀释法确定最低抑菌浓度(MIC)和最低杀菌浓度(MBC),通过菌落数直观地确定丁香酚对金黄色葡萄球菌的MIC值和MBC值;并以分光光度计法探究不同质量浓度丁香酚对金黄色葡萄球菌中苹果酸脱氢酶(MDH)和琥珀酸脱氢酶(SDH)酶活性的影响。结果表明,丁香酚对金黄色葡萄球菌的最低抑制浓度(MIC)为600 μg/mL,最低杀菌浓度(MBC)为700 μg/mL,其可将金黄色葡萄球菌菌体蛋白质质量浓度、苹果酸脱氢酶(MDH)酶活、琥珀酸脱氢酶(SDH)酶活分别降至0.033 mg/mL、8.28 U/mg、2.40 U/mL,原因可能是抑制了菌体三羧酸循环和电子链传递中相关关键酶的活性。 相似文献
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乙醛是啤酒中的主要风味物质,其代谢主要来自酵母细胞。酵母中乙醇脱氢酶及乙醛脱氢酶是乙醛代谢的关键酶,对乙醛变化起着重要作用。跟踪啤酒酵母发酵过程中相对酶活力及乙醛变化,发现两种乙醇脱氢酶和乙醛脱氢酶的相对酶活力与发酵过程乙醛含量变化具有一定相关性。同时对低产乙醛啤酒酿酒酵母kb2-4与出发菌株啤酒酵母kb进行发酵试验,跟踪检测相对酶活力及乙醛含量,其乙醇脱氢酶Ⅰ和乙醇脱氢酶Ⅱ及乙醛脱氢酶相对酶活力均高于出发菌株,平均增幅分别为15.5%,11.6%和5%。3种酶活性的变化协同作用可以使乙醛含量降幅最大为33.8%。 相似文献