低聚半乳糖润肠通便功能的研究

目的:研究低聚半乳糖的润肠通便作用。方法:依据《保健食品检验与评价技术规范-2003版》“通便作用检验方法”,将动物随机分为模型对照组、阴性对照组、低、中、高剂量组5组,经口给予不同剂量的低聚半乳糖10天后,测定小肠墨汁推进率及首次排黑便时间,6h排便粒数和排便总重量。结果:在便秘模型成立的条件下:三个剂量组与模型对照组相比,动物墨汁推进率、6h排便粒数、6h排便总重量高于模型对照组,首次排黑便时间低于模型对照组,差异均有非常显著性(P<0·01)。动物实验表明低聚半乳糖具有通便功能。     

生物活性物质—低聚半乳糖

介绍了生物活性物质－低聚半乳糖的性质、种类及化学结构，综述了它在促进人体有益菌群、抑制有害菌种群的生长、减少肠内腐败物质、促进钙吸收、改善血清脂质等方面的生理功能，从游离酶、固定化酶和完整细胞等角度，详细介绍了低聚半聚糖的制备技术及其生产现状与前景。     

复方苍术方调节肠道菌群及肠道保护作用的研究

本文探讨了复方苍术方调节肠道菌群及肠保护作用。给予复方苍术方后,中、高剂量组肠球菌及高剂量组肠杆菌菌落数(按lg CFU计)分别降低6.35%、8.17%及5.69%;中、高剂量组乳杆菌和双歧杆菌菌落数分别增加7.04%、6.74%、6.99%和8.10%,且高于阳性对照组;同时,中、高剂量组盲肠内容物p H值分别降低6.58%和5.26%;肠道组织病理结果显示复方苍术方低剂量组十二指肠、回肠及中、高剂量组十二指肠、空肠、回肠A/V比值分别增加29.84%、17.47%、56.01%、31.18%、20.09%、46.51%、30.52%和20.09%,且中、高剂量组空肠、回肠A/V比值明显高于阳性对照组。此外,复方苍术方低、中、高剂量组小肠墨汁推进率分别增加43.92%、69.93%和98.31%。研究结果表明,复方苍术方可能通过调节肠道菌群结构改善肠道微环境,且效果优于单用低聚半乳糖。     

The effect of prebiotics on adherence of probiotics

Prebiotics are generally considered to promote the function or viability of probiotics via their fermentation, but their effect on the adherence of probiotics is still unclear. In this study, we examined the effect of 4 commercially available prebiotics [Orafti GR, Orafti P95, and Orafti Synergy (Beneo GmbH, Mannheim, Germany), and Vivinal (Friesland Foods Domo, Amersfoort, the Netherlands)] and 3 simple saccharides (glucose, galactose, and lactose) on the adherence of 5 probiotic type strains, 2 lactococci starter cultures, and 5 potential dairy probiotic strains from the Culture Collection of Dairy Microorganisms (Tábor, Czech Republic). Adherence was tested in microtiter plates on the following types of substrate: polystyrene alone and polystyrene coated with either porcine mucus or cocultures of the human colon cell lines Caco2 and HT29-MXT (1:9 ratio of HT29-MXT:Caco2). Adherence was evaluated as a change in fluorescence in the well of a microtiter plate. The most commonly observed effect (with a few exceptions) of prebiotics was decreased adherence of the tested strains observed on all types of substrate. The tested saccharides, which are part of the residual compounds of the used prebiotics, had a very similar effect—eliciting a decrease in adherence ability in the majority of the probiotic strains.     

低聚半乳糖的制备和应用进展

对目前低聚半乳糖制备的五种方法,天然原料提取、天然多糖酸解、化学合成法、酶法及微生物发酵法进行了较为详细的介绍,同时也对低聚半乳糖在食品和医药行业中的应用进展进行了总结.     

Production of galactooligosaccharides using a hyperthermophilic β-galactosidase in permeabilized whole cells of Lactococcus lactis

Galactooligosaccharides (GOS) are novel prebiotic food ingredients that can be produced from lactose using β-galactosidase, but the process is more efficient at higher temperatures. To efficiently express the lacS gene from the hyperthermophile Sulfolobus solfataricus, in Lactococcus lactis a synthetic gene (lacSt) with optimized codon usage for Lc. lactis was designed and synthesized. This hyperthermostable β-galactosidase enzyme was successfully overexpressed in Lc. lactis LM0230 using a nisin-controlled gene expression system. Enzyme-containing cells were then killed and permeabilized using 50% ethanol and were used to determine both hydrolysis and transgalactosylation activity. The optimum conditions for GOS synthesis was found to be at pH 6.0 and 85°C. A maximum production of 197 g/L of GOS tri- and tetrasaccharides was obtained from 40% initial lactose, after 55 h of incubation. The total GOS yield increased with the initial lactose concentration, whereas the highest lactose conversion rate (72%) was achieved from a low lactose solution (5%). Given that a significant proportion of the remaining lactose would be expected to be converted into disaccharide GOS, this should enable the future development of a cost-effective approach for the conversion of whey-based substrates into GOS-enriched food ingredients using this cell-based technology.     

双歧杆菌和乳酸菌β-半乳糖苷酶转糖基作用的研究进展

双歧杆菌和乳酸菌作为一般认为安全的微生物,是β-半乳糖苷酶（β-galactosidase,β-gal）的较好来源。部分双歧杆菌和乳酸菌菌株能够产生具有转糖基活力的β-gal,以乳糖为底物可合成具有益生作用的低聚半乳糖（galactooligosaccharides,GOS）,而GOS产物的产量和组成受到β-gal的来源以及反应条件的影响。因此,本文总结了能够产生具有转糖基活力的β-gal的双歧杆菌和乳酸菌菌株,比较了两类来源的β-gal的酶学性质,并重点阐述了这两类β-gal在GOS合成中的应用。     

蛋白复合物增强免疫功能的实验研究

目的 评价蛋白粉与低聚半乳糖复合粉对小鼠免疫功能的影响。方法 按《保健食品检验与评价技术规范》2003版中增强免疫力功能检验方法, 采取灌胃方式, 按照小鼠0.83、1.67、5.0 g/(kg?bw)剂量给予蛋白复合粉30 d后, 研究对小鼠细胞免疫、体液免疫、单核-巨噬细胞功能、NK细胞活性功能的影响。结果 ConA诱导的小鼠脾淋巴细胞转化实验及迟发型变态反应实验中, 高剂量组(5.0 g/(kg?bw))与对照组比较, 数据有显著差异(P＜0.05)。碳廓清实验中, 中剂量组(1.67 g/(kg?bw))、高剂量组(5.0 g/(kg?bw))的吞噬指数a比对照组明显增加(P＜0.05)。NK细胞活性在中剂量组(1.67 g/(kg?bw))、高剂量组(5.0 g/(kg?bw))与对照组间比较有显著性差异(P＜0.05)。各剂量组对小鼠体重增长、胸腺指数、脾指数, 血清溶血素水平和抗体生成细胞数均无显著性影响。结论 蛋白复合粉能够增强细胞免疫功能、单核巨噬细胞功能, 提高NK细胞活性, 说明蛋白复合粉具有增强免疫力的作用。     

响应面法优化低乳糖奶水解工艺

牛奶及乳制品营养丰富,容易消化吸收,人称"白色血液",是最理想的天然食品。近年来我国乳业发展迅速,但与世界平均水平仍存在巨大的差距,制约我国乳业发展的一个重要原因就是乳糖不耐症。利用β-半乳糖苷酶对牛奶进行水解可生成易被人体吸收的葡萄糖、半乳糖及"双歧因子"低聚半乳糖,不仅能解决乳糖不耐症问题,还能增加牛奶的营养价值。本文在单因素初步试验的基础上,以低聚半乳糖合成率为响应指标,通过响应分析法对低乳糖水解工艺进行优化。结果表明,当反应温度为45.3℃、加酶量为2.5mL及反应时间为69.7min时,低聚半乳糖得率达到最大值6.15%。通过乳果糖试剂盒测定水解后低乳糖奶中乳果糖含量,平均含量为158.17mg/L。     

低聚半乳糖的研究进展

对低聚半乳糖的生理功能及生产方法进行了综述，并对其在食品工业中的应用和发展前景进行了展望。