小麦麸皮中淀粉水解工艺的研究

以还原糖含量为指标,在不加酶的情况下,研究了温度和时间对小麦麸皮水溶性还原糖含量的影响,并以此为依据选择中温淀粉酶对小麦麸皮中淀粉进行水解.通过单因素试验确定:在料水比为1:20,温度65°C,时间5 min,pH6.5(自然pH),加酶量为0.6 u/g的条件下.可以使小麦麸皮中淀粉水解为DE值6～10的糊精.     

大曲酒糖化阶段一株优势细菌分离鉴定

大曲酒发酵过程中,淀粉质为主要原料,在曲粉、窖泥和环境微生物的作用下水解为葡萄糖等可发酵性糖,同时在糖化的过程中,这些可发酵性糖在酵母和其它一些微生物的发酵作用下转化成乙醇。实验模拟发酵体系,通过监测糖化酶变化,结合微生物手段,挑选出糖化阶段优势细菌。经分子鉴定为地衣芽孢杆菌。地衣芽孢杆菌来源广泛,通过环境诱导可产生耐高温淀粉酶,利于酿造的生产。     

响应面法优化甘薯淀粉酶解条件的研究

在加酶量、作用时间、反应温度及pH四个单因素试验的基础上,运用响应面分析法,以甘薯汁中还原糖量为评价指标,对耐高温α-淀粉酶酶解甘薯汁中淀粉的最佳工艺进行了研究,并利用统计学方法建立了耐高温α-淀粉酶酶解甘薯汁中淀粉的二次多项数学模型.结果表明,最佳酶解条件为:加酶量55 U/mL;作用时间80 min;反应温度90℃.在最佳酶解条件下,甘薯汁中还原糖量达3.706 g/100mL,淀粉的酶解率为75.33%.水解后的甘薯汁过滤制得的饮料,无需添加稳定剂,即可达到饮料稳定性的理想效果,在饮料保存期内无沉淀产生.     

中国淀粉水解工业发展及其展望思考

用生物的酶法进行淀粉的水解转化是制造糖饴,酿造酒、醋食品的基本方法,为淀粉糖技术发展的趋势方向.本文介绍了国外淀粉糖工业技术发展的基本轨迹,回顾了中国淀粉水解工业,特别是酶法取代酸法制造淀粉糖及其技术发展的基本过程.根据实际生产和行业情况,对淀粉糖酶法生产技术的进一步提高,提出了开发新酶、提高酶活力、改变酶的最适作用条件等具有建设性的改进意见,指出思考了国内淀粉糖行业、果葡糖浆产业的市场、质量管理等方面存在的问题,企业只有在生产技术、管理、销售和规模等方面都付出更多的努力,才能取得较好的经济效益.     

Amylolytic Cultures of Lactobacillus acidophilus : Potential Probiotics to Improve Dietary Starch Utilization

ABSTRACT: The amylase activity of twenty strains of Lactobacillus species isolated from intestinal contents of pigs was studied in vitro. Hydrolysis of starch was measured by following the disappearance of starch in a broth medium during the growth of all three strains. The amount of enzyme activity varied among strains. Three strains (A-4, L9 and L23) were selected for further study based on their high amylolytic activity in a broth containing soluble starch as the only carbohydrate source. Strains A-4 and L23 were identified as L. acidophilus and strain L9 was identified as L. fermentum. Among the three cultures, L. acidophilus L23 was selected as a potential candidate for use as a probiotic for improving digestion of starch in pigs based on its growth and hydrolysis of raw starch. The enzyme activity of L. acidophilus L23 was associated with the cell envelope and that of L. fermentum L9 was extracellular. The enzyme activity of L. acidophilus A4 was found in both locations. The enzyme activity of L. acidophilus L23 was inducible rather than constitutive.     

豆瓣发酵瓣子中淀粉酶高产菌株的筛选及其酶活力的测定

以郫县豆瓣不同时期发酵瓣子为原料筛选淀粉酶高产菌株,利用淀粉酶水解圈作为筛选模型,通过筛选培养及酶活力的测定,得到产淀粉酶活力相对较高的菌株DD23,为80.24 IU/mL。通过菌落形态观察、生理生化鉴定和16S rDNA序列分析,确定DD23为蜡样芽胞杆菌（Bacillus cereus）。     

淀粉酶产生菌MSP13筛选及其产酶条件初步优化

从优质白酒窖泥中分离筛选出13 株产淀粉酶的兼性厌氧细菌,通过测定α-淀粉酶、β-淀粉酶、糖化酶和脱支酶酶活力,最终筛选出一株生产4 种淀粉酶活力均相对较高的菌株,并对其进行形态观察,生理生化指标和16S rDNA鉴定,确定该菌株为解淀粉芽孢杆菌,并将其命名为MSP13。对菌株MSP13产酶条件进行初步优化,确定其产酶的较佳条件是：CaCl2质量浓度0.15 g/L、MgSO4·7H2O质量浓度0.3 g/L,pH 5.5和温度37 ℃。优化后的菌株MSP13生产4 种酶的酶活力平均提高了31.645%。     

木聚糖酶法制备水溶性玉米膳食纤维的工艺研究

利用木聚糖酶对脂肪酶、淀粉酶、蛋白酶预处理后的玉米种皮进行酶解,制备水溶性膳食纤维,并对所得膳食纤维进行气相色谱分析。木聚糖酶酶解最佳工艺条件为:酶解时间40min、加酶量1．0ml/g、酶解温度45℃、pH4．8;酶法得到的可溶性膳食纤维的成分主要有木糖、阿拉伯糖、半乳糖和葡萄糖。     

淀粉酶型时间-温度指示卡的研制

本文以淀粉酶、淀粉和碘为原料,制作监测食品质量的时间-温度指示卡。通过试验确定了制作工艺参数。最终制作出的指示卡颜色变化明显,可以用于食品质量监测。     

Influence of the Heating Rate on the Pasting Properties of Various Flours

Viscoamylographic tests were carried out on six commercial flour samples, three wheat flours (WF), two semolinas (S) and one rice flour (RF), using the Brabender Micro Visco‐Amylo‐Graph (MVA). The slurries were subjected to a definite temperature profile (30°C‐95°C, 95°C×30 min, 95°C‐50°C, 50°C×30 min), stirring at 250 min⁻¹ and using a 300 cm·g_f cartridge and recording the viscosity (in Brabender Units, BU) as a function of temperature and time. The aim of this work was to evaluate the influence of different heating rates (1.5, 3.0, 5.0, 7.5, 10.0°C/min) on the pasting properties of the various flours. The peak viscosity of WFs and Ss increased when high heating rates were applied, while the RF showed similar pasting properties independently of the heating rate. These behaviours were mainly ascribed to the different molecular organisation of the starch granules, responsible of different swelling and gelatinising extents, and also to a different kinetic of alpha‐amylase inactivation according to the heating rate applied. The key role of the alpha‐amylase activity in controlling the pasting viscosity of the different samples was demonstrated by the viscoamylographic test performed in the presence of silver nitrate as enzyme inhibitor.