具有降血糖作用益生乳酸菌的筛选及其乳品的研究

发布时间：2018-03-01 16:48

本文关键词： 乳酸菌益生特性降血糖筛选发酵乳　出处：《陕西科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：高血糖可导致糖尿病,对人体的危害很大。乳酸菌已被公认为对人体有益的可食用菌群,具有多种功能性,目前还在不断研究其新的功能性,关于乳酸菌降血糖作用及其健康产品的开发研究已逐渐成为热点。本研究以从陕西、甘肃等地所采集的传统发酵食品中分离纯化的SL01、SL02、SL03、SL04、SL05、SL06、SL07、SL08、SL09、SL10、SL11、SL12、SL13、SL14、SL15、SL16、SL17、SL18等18株乳酸菌为实验菌株,首先研究其对胃液和肠液的耐受性及产酸能力,其次分别对其菌悬液、发酵上清液、细胞破碎物上清液与降血糖相关的性能,即:对α-葡萄糖苷酶、α-淀粉酶抑制性、还原能力、对自由基DPPH和超氧阴离子(O2-·)的清除能力等进行研究,筛选出综合能力较强的乳酸菌,并以此为菌株,对初步制备的发酵乳降血糖作用相关指标进行了分析检测。主要研究结果如下:乳酸菌的益生特性研究:通过对18株乳酸菌的形态特征,生长曲线,溶钙圈、产酸量及其对人工胃液和人工肠液的耐受性等方面的研究。结果表明:18株乳酸菌中16种为杆菌,2种为球菌;18株菌在24h后均可达到生长旺盛期;均具有产酸性能,其中溶钙圈直径在1.35cm~2.60cm,产酸量为6.84g/Kg~19.98g/Kg;18株菌株对胃肠液耐受能力相差较大,胃液3h存活率20%以下有2株,20%至60%的有13株,60%以上有3株分别为菌株SL03、SL02和SL07;肠液6h存活率在20%以下有2株,存活率在20%至75%有13株,75%以上有3株分别为菌株SL03、SL09和SL18。乳酸菌与降血糖作用相关的指标研究:分别研究了18株菌的菌悬液、发酵上清液、细胞破碎物上清液对α-葡萄糖苷酶和α-淀粉酶的抑制性、还原能力、对自由基DPPH和超氧阴离子(O2-·)的清除能力,结果表明其对与降血糖作用相关的指标基本都具有一定的作用,具体为:菌悬液对α-葡萄糖苷酶均具有抑制性,抑制率从5.71%至37.48%,且总体高于发酵上清液和细胞破碎物上清液,对α-淀粉酶无抑制性,菌悬液有17种具有还原能力,还原浓度从9.67μmol/L至46.13μmol/L,对自由基O2-·有清除力的有4种,清除率从3.50%至23.09%,对自由基DPPH均具有清除力,清除率从9.73%至36.63%;发酵上清液对α-葡萄糖苷酶均具有抑制性,抑制率从1.55%至24.62%,15种对α-淀粉酶具有抑制性,抑制率从5.14%到33.85%,发酵上清液均具有还原能力,还原浓度从44.75μmol/L至105.25μmol/L,总体高于菌悬液和细胞破碎物上清液,对自由基O2-·和自由基DPPH均具有清除能力,O2-·清除率从2.97%至34.18%,自由基DPPH清除率从18.83%至82.92%,总体高于菌悬液和细胞破碎物上清液;细胞破碎物上清液对α-葡萄糖苷酶均具有抑制性,抑制率从0.31%至25.47%,对α-淀粉酶无抑制性,细胞破碎物上清液均具有还原能力,还原浓度从1.93μmol/L至35.64μmol/L,14种对自由基O2-·有清除力,清除率从0.74%至14.97%,对自由基DPPH均具有清除力,清除率从4.45%至43.53%。乳酸菌的鉴定:对18株菌中降血糖作用指标较优的SL01、SL02、SL03、SL05、SL12和SL18等6株菌进行了进一步鉴定,经形态学鉴定和16S rRNA基因测序结果表明,SL01为Lactobacillus sp.,SL02为Lactobacillus casei,SL18为Enterococcus faecium,SL03、SL02和SL12均为Lactobacillus reuteri。乳酸菌发酵乳的制备及其与降血糖作用相关指标的研究:以上述6株乳酸菌为发酵菌株进行发酵乳的制备,并分析检测发酵过程中与降血糖相关的指标变化,结果为:6株菌制备的发酵乳均具有不同程度的降血糖活性,不同温度对于发酵乳的降血糖作用相关指标活性影响不同。较优发酵条件为SL01发酵乳温度37℃发酵72h,SL05发酵乳温度41℃发酵72h,SL02和SL18发酵乳温度37℃发酵56h,SL12发酵乳温度41℃发酵48h,SL03发酵乳温度37℃发酵64h;将6株菌制备的发酵乳等量混合后,其降血糖活性显著增强,其中对α-葡萄糖苷酶和α-淀粉酶的抑制率分别为25.68%和65.27%,还原能力为152.75μmol/L,O2-·清除率为40.82%,自由基DPPH的清除率为65.29%,冷藏21d之后,活菌数为5.3×107CFU/mL,酸度在109 oT以下,α-葡萄糖苷酶和α-淀粉酶的抑制率分别保持在20.58%和61.23%,还原浓度保持在143.38μmol/L,O2-·清除率保持在30.97%,DPPH清除率保持在52.62%,冷藏后混合乳降血糖作用相关指标活性仍保持了较高值。本文通过乳酸菌的筛选、益生特性研究、降血糖作用相关指标研究及其发酵乳的制备与降血糖作用研究,可为进一步研究开发新型功能性乳酸菌发酵乳提供一定的理论与实验依据。
[Abstract]:High blood sugar can lead to diabetes, great harm to the human body. The lactic acid bacteria has been recognized as beneficial to human edible flora, with a variety of functions, is continuing to study the new features of the development of research on the hypoglycemic effect of lactic acid bacteria and health products has gradually become the hot spot in this study from Shaanxi. Separation and purification of traditional fermented food, the acquisition of Gansu and other places in SL01, SL02, SL03, SL04, SL05, SL06, SL07, SL08, SL09, SL10, SL11, SL12, SL13, SL14, SL15, SL16, SL17, SL18 and other 18 strains of lactic acid bacteria strains, we first study its tolerance to gastric juice and intestinal juice and acid production ability, followed by the bacterial suspension and supernatant, performance, broken cell supernatant associated with lowering blood sugar: the alpha glucosidase, alpha amylase inhibition, reducing power, DPPH free radical and superoxide anion (O2- -) of the scavenging capacity etc. Study on screening of lactic acid bacteria, strong comprehensive ability, and as a strain of fermented milk, preliminary preparation reduced blood glucose related indexes were detected. The main results are as follows: Study on probiotic characteristics of lactic acid bacteria: the morphological characteristics of 18 strains of lactic acid bacteria growth curve, dissolved calcium circle, study acidity and tolerance on artificial gastric juice. The results showed that the 18 strains of lactic acid bacteria in 16 kinds of bacteria, 2 for Staphylococcus aureus 18 strains; can achieve growth in 24h after Washings; had acid production, which dissolved calcium circle diameter in 1.35cm~2.60cm acid production was 6.84g/Kg~19.98g/Kg; 18 strain difference on gastrointestinal tolerance, gastric 3H survival rate below 20% and 2 strains, 20% to 60% of the 13 strains, 3 strains were more than 60% strains SL03, SL02 and SL07; intestinal 6h survival rate below 20% in 2 strains, the survival rate in 20% to 75% in 13 strains, More than 75% of 3 strains were strains SL03, SL09 and SL18. index to study the hypoglycemic effect of lactic acid bacteria and related: 18 strains of bacterial suspension and supernatant, broken cell supernatant of alpha glucosidase and alpha amylase inhibition, reduction ability of free radical DPPH (O2- -) and superoxide anion scavenging ability, the results showed that the correlation with the hypoglycemic effect of basic indicators has a certain role, in particular: the bacterial suspension showed inhibition of alpha glucosidase inhibitory rate, from 5.71% to 37.48%, and was higher than that of fermentation supernatant and cell lysate supernatant. The alpha amylase inhibiting bacterial suspension, 17 has the ability to restore, restore the concentration from 9.67 mol/L to 46.13 mol/L, the O2- radical scavenging capacity of 4, the clearance rate from 3.50% to 23.09%, with scavenging DPPH free radical scavenging rate from 9.73% to 36.. 63%; fermentation supernatant has inhibition of alpha glucosidase inhibitory rate, from 1.55% to 24.62%, with 15 inhibition of alpha amylase inhibition rate from 5.14% to 33.85%, the fermentation supernatant showed good reducing ability, reducing the concentration from 44.75 mol/L to 105.25 mol/L, the overall high in suspension and the cell supernatants were broken, with the radical scavenging activity of O2- and DPPH radical, O2- radical scavenging rate from 2.97% to 34.18%, DPPH free radical scavenging rate from 18.83% to 82.92%, higher than the overall bacterial suspension and supernatant of cell disruption; broken cell supernatant on alpha glucosidase inhibitory have. The inhibition rate from 0.31% to 25.47%, the alpha amylase inhibiting cell supernatant were broken, has the ability to restore, restore the concentration from 1.93 mol/L to 35.64 mol/L, 14 kinds of O2- radical scavenging capacity, scavenging rate from 0.74% to 14.97%, with the free radical DPPH There are clear, the clearance rate of 43.53%. to the identification of lactic acid bacteria from 4.45%: the hypoglycemic effect index of optimal SL01, 18 strains SL02, SL03, SL05, SL12 and SL18 and other 6 strains were further identified by morphological identification and 16S rRNA gene sequencing results showed that SL01 Lactobacillus sp., SL02 Lactobacillus casei, SL18 Enterococcus faecium, SL03, SL02 and SL12 are Lactobacillus reuteri. of lactic acid bacteria fermented milk preparation and hypoglycemic effect of relevant indicators: the 6 strains of lactic acid bacteria fermentation strains were fermented milk preparation, and analysis of changes in indicators of blood glucose detection in the fermentation process and the lower correlation results: 6 strains of Lactobacillus fermentation were prepared with hypoglycemic activity in different degree, relevant indicators of the hypoglycemic effect of different temperature on the activity of fermented milk have different effects. The optimal fermentation conditions for SL01 fermented milk fermentation temperature 37 C 7 2H, SL05 fermented milk fermentation temperature 41 72h, SL02 and SL18 in fermented milk temperature 37 56h fermentation, SL12 fermented milk fermentation temperature is 41 DEG 48h, SL03 fermented milk fermentation temperature is 37 DEG 64H; 6 strains preparation of fermented milk mixture, its hypoglycemic activity was significantly enhanced and the inhibition of alpha glucosidase and alpha amylase were 25.68% and 65.27%, reducing capacity of 152.75 mol/L, O2- clearance rate was 40.82%, the free radical scavenging rate of DPPH was 65.29%, refrigerated after 21d, number of live bacteria is 5.3 * 107CFU/mL, pH below 109 oT, inhibition of alpha glucosidase and alpha amylase rate was kept at 20.58% and 61.23%, the reduction of concentration is kept at 143.38 mol/L, O2- removal rate remained at 30.97%, the clearance rate of DPPH remained at 52.62%, after cold storage of mixed milk hypoglycemic activity index still has high value. Through the screening of lactic acid bacteria, study on probiotic characteristics drop Studies on related indicators of blood glucose, preparation and hypoglycemic effect of fermented milk can provide theoretical and experimental basis for further research and development of new functional lactic acid bacteria fermented milk.

【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS201.3

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