体外筛选降胆固醇双歧杆菌实验

测定了实验室保藏9株食品级双歧杆菌体外降胆固醇的能力以及耐酸、耐胆盐和细胞粘附的益生特性.结果表明,9株受试菌株具有良好的耐酸、耐胆盐和细胞粘附特性,且5株菌降胆固醇均达到50%以上.从中选择6#菌株作为今后益生菌制剂和功能性乳制品开发的潜在菌种.     

体外筛选降胆固醇双歧杆菌实验

测定了实验室保藏9株食品级双歧杆菌体外降胆固醇的能力以及耐酸、耐胆盐和细胞粘附的益生特性。结果表明,9株受试菌株具有良好的耐酸、耐胆盐和细胞粘附特性,且5株菌降胆固醇均达到50%以上。从中选择6#菌株作为今后益生菌制剂和功能性乳制品开发的潜在菌种。      

降胆固醇益生乳酸菌的体外筛选

从传统发酵制品中筛选出6株降胆固醇的乳酸菌并在体外测定了降胆固醇的能力,其中菌株GL-10和LBA-11高达45%;同时测试了这些菌株的耐酸和耐胆盐性、细胞黏附、抑菌性的益生特性。结果表明,菌株GL-A-11,GL-11,ZPC-15能在pH值为2蒸馏水下存活1 h;GL-10,GL-A,ZPC-13能在质量分数为2%的胆盐混合液中存活12 h;GL-10对人结肠腺癌细胞系HT-29细胞黏附性最强,达4.8个/细胞,其次是菌株GL-A,ZPC-13,GL-11为3.7个/细胞左右,所有菌株对常见致病菌都有明显抑制作用。从中选择出乳酸菌GL-A作为今后益生菌制剂和功能性乳制品开发的潜在菌种。     

酸菜中降胆固醇功能植物乳杆菌的体外筛选

以分离自东北家庭自制酸菜中的9株植物乳杆菌为研究对象,采用邻苯二甲醛法筛选具有降胆固醇功能的乳杆菌,并通过耐酸、耐胆盐及抗生素敏感性实验,分析菌株的益生特性。结果表明,多株植物乳杆菌具有良好的降胆固醇功能,其中菌株S56的脱除胆固醇的量最高,达到22.40μg/mL。实验菌株均能耐受pH 3.0的酸度和10 g/L的牛胆盐。其中菌株S2-6、S2-5、S4-1和S56在pH 2.0的环境中能保持生长1 h,具有较强的耐酸性。     

乳酸菌合生元的研究进展

合生元(synbiotics)是由益生菌(probiotics)和益生元(prebiotics)组成的微生物制剂,可同时具有益生菌和益生元的作用,并以肠道为靶点位置发挥益生功能.乳酸菌(lactic acid bacteria,LAB)是肠道中最重要的益生菌成员,无论是用于商品化生产,还是用于基础研究,LAB是最广泛用...     

益生菌种的应用和市场趋势

本文对全球益生菌种的最新研究及市场趋势作一简要阐述，同时，也对丹尼斯克公司在益生菌种的此前沿领域应用研究进展作了介绍。     

具有降胆固醇功能的罗伊氏乳杆菌的筛选及其益生作用

为获得具有较强降胆固醇功能的益生菌株,试验从内蒙古呼伦贝尔满洲里通达牧场制作的奶豆腐中筛选分离菌株,并采用邻苯二甲醛法测定菌株降胆固醇的能力,从中选出降胆固醇能力强的菌株,通过形态学鉴定、生理生化及16S rDNA对菌株进行鉴定,并测定了其耐受酸、胆盐和胃肠液的能力。结果筛选分离出5株具有降胆固醇功能的菌株,其中一株菌对胆固醇降解能力最强,降解率达50.60%,经鉴定此株菌为罗伊氏乳杆菌（Lactobacillus reuteri）,将其命名为HCS02-001（CGMCC No. 19746）;经对酸、胆盐及胃肠液的耐受试验,该株菌在pH 3.0和pH 2.0的环境中培养17 h后存活率分别为86.80%和85.52%;在0.30%、0.50%的胆盐浓度环境中培养17 h后存活率分别为97.42%和95.17%;在人工胃液中作用3 h,存活率为96.74%;在人工肠液中作用4 h,存活率高达98.41%。该研究筛选出了一株具有较好降胆固醇功能的罗伊氏乳杆菌（Lactobacillus reuteri）,其具有较强的耐受酸、胆盐环境和胃肠液的能力,对关于降胆固醇功能方面的产品研究开发具有重要意义。     

干酪乳杆菌21008体外降胆固醇活性研究

用胆固醇氧化酶指示平板和测定胆固醇氧化酶活力的方法对干酪乳杆菌21008是否具有产生胆固醇氧化酶的能力进行了研究,并以添加胆固醇的MRS培养基和蛋黄对菌株降胆固醇能力进行了评价。结果发现干酪乳杆菌能产生胆固醇氧化酶类似物,并且测得胞内酶活为302.7U/L,但没有胞外酶。菌株使MRS-CHO培养基中的胆固醇降低69.5%,主要是通过菌体细胞吸收、转化作用;而在蛋黄中发酵,优化条件下:V蛋黄∶V水=2∶1,接种量8%,发酵30h,胆固醇降低16.82%,pH降为5.57。     

干酪乳杆菌21008体外降胆固醇活性研究

用胆固醇氧化酶指示平板和测定胆固醇氧化酶活力的方法对干酪乳杆菌21008是否具有产生胆固醇氧化酶的能力进行了研究,并以添加胆固醇的MRS培养基和蛋黄对菌株降胆固醇能力进行了评价。结果发现干酪乳杆菌能产生胆固醇氧化酶类似物,并且测得胞内酶活为302.7U/L,但没有胞外酶。菌株使MRS-CHO培养基中的胆固醇降低69.5%,主要是通过菌体细胞吸收、转化作用;而在蛋黄中发酵,优化条件下:V蛋黄∶V水=2∶1,接种量8%,发酵30h,胆固醇降低16.82%,pH降为5.57。      

鲈鱼肠道来源降胆固醇乳酸菌分离筛选及其益生功能评价

该研究探讨了从健康鲈鱼肠道中筛选分离出高效降胆固醇的乳酸菌,通过菌株鉴定、耐酸、耐胆盐、疏水性、自凝聚力和代谢物抑菌性评价的测定,评价并考察其体外益生作用。采用胆盐水解酶测定和体外降胆固醇试验,筛选分离得到一株高效降胆固醇的菌株ZG2YLu05,其胆盐水解酶（BSH）粗酶活和胆固醇去除率分别为0.82 µmol/(h?mL)和50.09%;在pH 3.0的培养条件下培养8 h,菌株的耐酸存活率为83.33%;在胆盐浓度0.3%的培养条件下培养8 h,菌株的耐胆盐存活率高达89.31%;在二甲苯中菌株的疏水性为46.82%,静置24 h后菌株的自凝聚力为92.93%,说明菌株具有良好的黏附潜力;菌株代谢物对大肠杆菌、金黄色葡萄球菌和沙门氏菌都有明显的抑制作用;经形态学观察和16S rDNA鉴定为戊糖乳杆菌（Lactiplantibacillus pentosus）。该菌株能够作为潜在降胆固醇乳酸菌用于开发辅助降脂益生菌制剂的生产。     

Functional Magnetic Nanoparticles for Highly Efficient Cholesterol Removal

In this study, magnetic nanoparticles functionalized with carboxylated β‐cyclodextrin (CM‐β‐CD; referred to Fe₃O₄@CM‐β‐CD) were synthesized and used for the efficient removal of cholesterol from milk and egg yolk via host–guest interactions. The results of Fourier‐transform infrared, X‐ray photoelectron spectroscopy, and thermogravimetric analysis indicated that the CM‐β‐CD was successfully conjugated to the surface of Fe₃O₄, and the amount of CM‐β‐CD attached on Fe₃O₄@CM‐β‐CD was determined to be 9.164%. The X‐ray diffraction and transmission electron microscopy data revealed that the process of CM‐β‐CD coating did not result in a phase change of the Fe₃O₄, and the Fe₃O₄@CM‐β‐CD nanoparticles were determined to have an average size of about 15 nm. The results of isotherm adsorption and kinetic properties indicated that CM‐β‐CD functionalization increased the cholesterol removal efficiency, and the characteristics of cholesterol adsorption on Fe₃O₄@CM‐β‐CD were fitted well with the Langmuir adsorption model and Lagergren pseudo‐1st‐order kinetic models. Furthermore, compared with the Fe₃O₄ nanoparticles, the functionalized Fe₃O₄@CM‐β‐CD nanoparticles exhibited greater cholesterol removal efficiency, and saponification of the milk and egg yolk was found to be beneficial for the cholesterol removal; using the Fe₃O₄@CM‐β‐CD nanoparticles, 98.8% and 94.6% of the cholesterol was extracted in 1 h from saponified milk and egg yolk, respectively, and the Fe₃O₄@CM‐β‐CD nanoparticles still displayed efficient cholesterol removal after 6 reuses.     

食品中胆固醇脱除工艺的研究

介绍了利用β－环状糊精脱除原料奶、稀奶油和蛋黄液中胆固醇的方法和工艺过程，地脱除效果进行了讨论。     

水溶性与水不溶性膳食纤维对油脂、胆固醇和胆酸钠吸附作用研究

采用离体实验模拟人体胃和肠道的pH环境,探讨了小麦纤维,大豆纤维,水果纤维以及由三者和低聚果糖组成的复合膳食纤维产品分别对油脂,胆固醇,胆酸钠的吸附能力,为功能性复合膳食纤维产品的研发提供依据。结果表明,对不饱和脂肪花生油的吸附能力表现为小麦纤维2．68g／g〉清多冲剂2．3sg／g〉大豆纤维1．76g／g～水果纤维1．66g／g;对饱和脂肪猪油的吸附能力表现为小麦纤维5．64g／g〉清多冲剂5．37g／g〉大豆纤维5．14g／g～水果纤维4．S7g／g。对胆固醇和胆酸钠的吸附,水果纤维能力最强,分别为11．34g／g和73．70mg／g,清多冲剂次之中,其吸附量为9．23g／g和45．37mg／mL;均高于小麦纤维和大豆纤维。另外,在胃pH条件下,几种膳食纤维对胆固醇的吸附能力显著低于在肠道pH条件下。实验结果说明,复合膳食纤维产品“清多冲剂”能综合三种单一种类膳食纤维的优点。     

去除胆固醇细菌的分离、鉴定及其性能的初步研究

从金华火腿、光明酸奶、光明奶酪、味全乳酸菌饮品及泡菜等样品中分离得到100余株乳酸菌菌株,利用高胆固醇MRS-CHOL培养基测定其体外胆固醇去除能力,从中筛选得到一株高效去除胆固醇的菌株JH-1,去除率达到48.68%。通过形态学特征、生理生化特征和16S rDNA序列同源性分析,鉴定菌株JH-1为短乳杆菌(Lactobacillus brevis)。研究了培养时间、接种量、培养温度、培养基初始pH以及基质中胆固醇胶束质量浓度对胆固醇去除率的影响,发现短乳杆菌JH-1分别在时间为48 h,接种量体积分数为3%,培养温度为37℃,初始pH值为6,胆固醇胶束质量浓度为1 mg/mL时,胆固醇去除率达到最大。     

超声波辅助酶解法提取食用猪油工艺优化及胆固醇脱除

为开发猪油的提取新工艺,以猪脂肪组织为原料,采用超声波辅助中性蛋白酶酶解法提取食用猪油。在单因素试验的基础上,以猪油的提取率为考察指标,采用正交试验方法研究蛋白酶添加量、酶解时间、超声波功率和超声时间对猪油提取率的影响,并通过吸附条件的优化,研究β-环糊精、羧甲基纤维素及马铃薯变性淀粉3 种吸附剂对猪油胆固醇的脱除效果。结果表明：各因素对猪油提取率的影响从大到小依次为蛋白酶添加量＞酶解时间＞超声波功率＞超声时间;超声波辅助酶解提取食用猪油的最优工艺为蛋白酶添加量550 U/g、酶解时间80 min、超声波功率720 W、超声时间120 s,在此条件下,猪油的提取率为（95.14±1.65）%;3 种吸附剂对猪油胆固醇均具有明显的吸附效果,脱除能力依次为β-环糊精＞羧甲基纤维素＞马铃薯变性淀粉。     

不同麦麸材料吸附脂肪和胆固醇的研究

目的探讨黑曲霉固体发酵麦麸、液体发酵麦麸和酶解(多糖水解酶和阿魏酸酯酶)麦麸的持水力、对脂肪和胆固醇的吸附作用,为其在食品中的应用提供依据.方法采用离体法.主要结果麦麸经发酵和酶解后,持水力和对脂肪的吸附能力大大增加,酶解后持水力增加1倍以上,对脂肪的吸附能力增加48.7%.固体发酵麦麸和酶解麦麸对鸡蛋中胆固醇的吸附能力大大高于原麦麸,而液体发酵麦麸则差于原麦麸.扫描电镜观察结果表明,发酵或酶解后麦麸的上述物性之所以发生较大改变,其主要原因是由于麦麸的内、外结构产生了较大变化.     

分离自酸菜汁的乳酸乳球菌体外去除胆固醇特性

将从自然发酵的酸菜汁中分离鉴定的乳酸乳球菌(Lactococcus lactis)接种于高胆固醇培养液MRSO-CHOL中,分别改变茵的培养时间和接种量以及培养基中胆盐质量浓度和胆盐种类,发现乳酸乳球菌对培养液中胆固醇的体外去除率在72 h前随时间的增加而提高,72～96 h基本维持稳定,96 h后下降;随着接种量的增加,胆固醇的去除率增加;培养液不舍胆盐时,乳酸乳球菌的胆固醇去除率很低,仅为4.51%.胆盐质量浓度为0～0.3 mg/mL时,随着胆盐质量浓度的升高,胆固醇的去除率也逐渐升高.胆盐质量浓度高于0.3 mg/mL时,胆固醇去除率下降;牛磺胆酸钠对胆固醇的去除效果最佳.     

柠檬干片高效褐变抑制剂筛选

检测了几种天然、安全的褐变抑制剂对柠檬干片褐变抑制效果的影响,并就柠檬干片褐变抑制剂配方进行探索,结果显示0.25% L-Cys结合0.20%肉桂酸及0.50% EDTA-2Na可显著抑制柠檬干片的褐变.     

Optimizing Cholesterol Removal in Cream Using β-Cyclodextrin and Response Surface Methodology

Average cholesterol reduction increased as β-cyclodextrin concentration increased, regardless of other factors. The process was optimized using RSM. When β-cyclodextrin addition was 10%, the effect of stirring speed was more noticeable than that of stirring time. When stirring speed was at 1,600 rpm, 94.2% of cholesterol was reduced in 30 min. When stirring time was 20 min, the cholesterol was reduced 97.99% using 15%β-cyclodextrin. When stirring speed was 1,200 rpm, the effect of β-cyclodextrin addition was greater than that of stirring time. Although the percentage of cholesterol reduction varied with different factors and conditions, about 94% of cholesterol was removed from cream.     

Cholesterol Content and Methods for Cholesterol Determination in Meat and Poultry

Abstract: Available data for cholesterol content of beef, pork, poultry, and processed meat products were reported. Although the cholesterol concentration in meat and poultry can be influenced by various factors, effects of animal species, muscle fiber type, and muscle fat content are focused on in this review. Oxidative red muscles tend to have greater total lipid and cholesterol contents, although differences in the same types of muscles or cuts have been reported. Moreover, contradictory results among various studies suggest that unless there are pronounced changes in muscle structure and composition, cholesterol content is unlikely to be affected. Second, multiple issues in cholesterol analysis, including sample preparation, detection, and quantification, were evaluated. Cholesterol content of meat and poultry has been determined mostly by colorimetry and chromatography, although the latter has become predominant because of technological advances and method performance. Direct saponification has been the preferred method for hydrolyzing samples because of cost‐ and time‐effectiveness. The extraction solvent varies, but toluene seems to provide sufficient recovery in a single extraction, although the possible formation of an emulsion associated with using toluene requires experience in postsaponification manipulation. The most commonly used internal standard is 5α‐cholestane, although its behavior is not identical to that of cholesterol. Cholesterol can be analyzed routinely by gas chromatography (GC)‐flame ionization detector without derivatization; however, other methods, especially high‐performance liquid chromatography (HPLC) coupled with different detectors, can also be used. For research purposes, HPLC‐ultraviolet/Visible/photodiode array detector with nondestructiveness is preferred, especially when cholesterol must be separated from other coexisting compounds such as tocopherols. More advanced methods, such as GC/HPLC‐isotope dilution/mass spectrometry, are primarily used for quality control purposes.