Enzymatic Starch Hydrolysis of Extruded Potato Peels

Potato peels discarded by potato processors are a potential source of dietary fiber and starch. This starch may be hydrolyzed for fermentation to value-added products. Dried steam peels were extruded at 135°C and 22% feed moisture and digested with α-amylase and/or amyloglucosidase. Two barrel temperatures and feed moistures were also studied. Glucose was measured colorimetrically at O,1,2,4,8 and 24h of incubation. All peels treated with either no enzymes or α-amylase alone produced minimal glucose. Nonextruded peels digested with both enzymes produced more glucose than did those treated with amyloglucosidase alone. Complete digestion of starch occurred in extruded peels digested with amyloglucosidase, but not when α-amylase was used.     

Enzymatic Hydrolysis of Wheat Starch into Glucose

In the presented research, glucose hydrolyzates were obtained by acting on wheat starch, which was liquefied with the aid of bacterial α-amylase, with Spezyme GA 300W Y553, an enzymatic preparation composed of glucoamylase and lysophospholipase, as well as with Amyloglucosidase AMG 300L, a glucoamylase preparation. The following physical and chemical properties of the obtained hydrolyzates were tested the glucose equivalent, the filtration power, the colour factor and the transparency factor. In the process of saccharification of wheat starch into glucose, the optimum dose of Spezyme, the enzymatic complex, is a concentration equal to 0.3%/d.m., at which after 72 h of process duration, the maximum 98 DE reducibility was achieved. Using the Spezyme preparation, which, thanks to the fact that apart from glucoamylase, it contains lysophospholipase, results in an improvement of the filtration power of hydrolyzates obtained with the participation of this preparation.     

A Study of Enzymatic Hydrolysis of Starch in Potato Pulp

ABSTRACT: Enzyme dosage of a-amylase and amyloglucosidase greatly affected starch hydrolysis in the potato pulp. However, the effect of amyloglucosidase was the most critical. Starch hydrolysis was also influenced by the powder size of pulp. An increase in pulp size and pulp concentration resulted in a lower degree of starch hydrolysis to glucose. Lower starch gelatinization enthalpy of potato pulp compared to that of dry matter and pure potato starch indicates that there was some interaction between starch, nonstarch polysaccharides, and proteins.     

The Production and Properties of Glucose Syrups I. Production of Glucose Syrups by Enzymatic Hydrolysis of Starch

Certain metal ions are shown to influence the enzymic hydrolysis of maize starch. Amyloglucosidase was not affected by the metal ions but á- and ß-amylase were affected by varying degrees. Calcium ions produced a positive effect with both fungal and bacterial α-amylases but no effect with ß-amylase, whilst zinc, ferric and lead ions produced negative effects or no effect. A simultaneous enzymic hydrolysis (using α- and ß-amylases) and catalytic hydrogenation showed enzyme inhibition by the nickel catalyst. High hydrogen pressure (100 at) had little effect on the enzymes. The hydrolysis and hydrogenation of the starch fraction of milled whole defatted maize was also shown to be feasible.     

淀粉结构对其酶解性能影响的研究进展

淀粉因其来源不同而在结构上表现出较大差异,这些结构上的差异对淀粉的酶解性能产生很大影响。文章从淀粉的分子结构与颗粒结构两方面,阐述了淀粉中直链淀粉、支链淀粉、直链淀粉-脂质复合结构、磷含量、淀粉颗粒大小和形状、颗粒结晶结构以及复合结构对淀粉酶解性能的影响,并提出存存的问题及研究方向。     

复合纤维素酶对杨木SGW浆的游离度和纤维比表面积的影响

研究了杨木SGW浆酶改性过程中,酶解产物、浆的游离度增加值和纤维的比表面积的变化规律。结果表明,在酶解初期,复合纤维素酶很快吸附到SGW浆纤维的表面发生酶解,使还原糖产生速率较高。而液相中酶蛋白浓度下降很快。伴随酶解过程的进行,浆的游离度增加值和纤维的比表面积呈现“波浪形”变化。这可能是复合纤维素酶的酶解作用使纤维表面产生“剥皮效应”所致。     

水解条件对挤压膨化高温豆粕酶解物免疫活性的影响

研究合理的水解工艺以有效提高高温豆粕的免疫活性。采用二次旋转回归法优化水解条件,以水解温度、酶添加量、底物添加量、酶解时间为影响因素,以淋巴细胞增殖指数(SI)为检测指标,运用SPSS13.0软件分析,最终用Design Expert 7.0.0软件优化出最优的水解条件。最优的工艺条件为：胰蛋白酶添加量7999.97U/g,酶解温度55.14℃,水解时间4.34h,底物添加量(底物与加水量之比)4.41%,经MTT法测定,此条件下酶解物对ConA诱导的小鼠脾淋巴细胞的免疫刺激指数最高,为1.1894。     

酶催化水解对玉米淀粉结构的影响研究

颗粒状玉米淀粉经α-淀粉酶催化水解后,应用SEM、X射线衍射和热失重(TG)对产品进行了分析.检测结果表明,α-淀粉酶催化水解玉米淀粉时,其收率与酶的浓度和反应时间成反比;颗粒状玉米淀粉发生酶催化水解时,α-淀粉酶首先使淀粉形成多孔状结构,并进一步使颗粒破裂,断裂的颗粒碎片上显示出淀粉颗粒内部具有层状的生长环结构;酶催化水解不能提高玉米淀粉颗粒的结晶度;酶解时间较长时,产品的热稳定性降低.     

挤压剪切活化对添加耐高温α-淀粉酶脱胚玉米淀粉结构和理化特性的影响

本研究通过偏光显微镜、扫描电子显微镜、热台显微镜、X射线衍射、差示扫描量热分析、傅里叶变换红 外光谱分析等手段,研究原脱胚玉米、挤压脱胚玉米和添加耐高温α-淀粉酶挤压脱胚玉米的淀粉结构及性质变化, 并探究其相互关系,揭示挤压剪切活化对脱胚玉米的淀粉颗粒机械力化学效应。研究表明：与原脱胚玉米和挤压脱 胚玉米相比较,挤压处理对添加耐高温α-淀粉酶脱胚玉米的淀粉结构及性质产生显著影响,酶解力和糊化度增大,碘 蓝值、直链淀粉含量减小。添加耐高温α-淀粉酶挤压脱胚玉米淀粉颗粒形貌破坏,偏光十字破坏,结晶度变小;升温糊 化过程中,焓变降低;挤压使淀粉颗粒的结晶结构破坏,淀粉颗粒发生聚集,破损淀粉颗粒易糊化和裂解。     

普鲁兰酶酶解对葛根淀粉理化特性的影响

研究了普鲁兰酶酶解对颗粒态葛根淀粉理化特性的影响。采用快速黏度分析仪（RVA）、差示量热扫描仪（DSC）、偏光显微镜、扫描电子显微镜（SEM）、激光粒度仪、傅里叶红外光谱仪（FTIR）、X射线衍射仪（XRD）对酶解前后葛根淀粉的糊化特性、抗性淀粉含量、热性能、形貌、颗粒大小、结晶结构和分子结构进行了分析。结果表明,酶解后葛根淀粉的峰值黏度和崩解值分别降低了28.33%和94.69%,谷值黏度、最终黏度和回生值分别增加了12.53%、12.47%和12.37%;抗性淀粉含量从1.29%上升至4.60%。酶解后淀粉的偏光十字仍然存在,但颗粒发生膨胀,粒度变大,表层出现剥离;DSC吸热峰向高温区偏移,但吸热焓下降;酶解促进了淀粉分子短程有序结构的生成;葛根淀粉经酶解后,其相对结晶度从37.31%降低至29.10%。     

果胶酶酶解红枣浆工艺研究

以市售和田大枣为原料,利用果胶酶处理红枣浆,以提高红枣浆出汁率。通过单因素试验得到在酶解温度30℃~50℃范围内、酶解pH 4.5~5.5、果胶酶添加量0.01%~0.03%、酶解时间60 min~80 min红枣浆出汁率较高,酶解效果较好;通过正交试验得到果胶酶处理红枣浆最佳工艺条件为酶解温度40℃,酶解pH 5.5,果胶酶添加量0.03%,酶解时间60 min,此条件下红枣浆出汁率为87.5%,比未添加果胶酶进行酶解提高了19%。     

Near Infra-red Monitoring of Enzymatic Hydrolysis of Starch

NIR measurement was carried out for a starch dispersion circulating from a reactor to an NIR flow-through cell over a wavelength range of from 1000 to 2500 nm in 2 nm increments. Multiple regression analysis between NIR and HPLC shows a good correlation. It is shown that the NIR method can be used to determine glucose quantitatively in real time during enzymatic hydrolysis, and that NIR may be employed for controlling the reaction in a bioreactor.     

Effect of Enzymatic Hydrolysis of Wheat Starch on Amylose‐Lipid Complexes Stability

In the process of enzymatic hydrolysis of wheat starch to glucose, the presence of amylose‐lipid complexes (AML's) decreases swelling and dissolving capacity and the water binding capacity of starch, thus impeding the access of amylolytic enzymes to the starch granules. The aim of the work was to define the relationship between the stability of AML's and the conditions of the enzymatic hydrolysis of wheat starch such as the kind of enzymatic preparation (only amylolytic or both amylolytic and lipolytic) and time of hydrolysis. Hydrolysates were produced from wheat starch liquefied with bacterial α‐amylase BAN 240L, subjected to further treatment with the enzymatic preparation Spezyme GA 300W, containing glucoamylase and lysophospholipase and, for comparison, only with a glucoamylase preparation (AMG 300L). The effect of amylolytic and lipolytic enzymes on the stability of AML's in the process of wheat starch hydrolysis was estimated. The amount of fatty acids released during hydrolysis was determined with gas‐liquid chromatography (GLC) and by differential scanning calorimetry (DSC) measuring the enthalpy of decomposition of AML's. The investigations revealed a differentiated effect of the individual enzymatic preparations on the degree of degradation of AML's. Amylose‐lipid complexes were more susceptible to the attack of preparation Spezyme GA 300W than to the digestion by α‐amylase BAN 240 L and glucoamylase AMG 300L.     

复合酶解法制备多孔淀粉的工艺研究

多孔淀粉是一种新型酶变性淀粉,本文采用α-淀粉酶和糖化酶复合酶解法制备多孔淀粉,对其工艺条件进行研究,当α-淀粉酶和糖化酶的比例为1:5、反应温度60℃,反应时间32h,pH4.5,酶用量2.0%时,可得到吸油率较高的多孔淀粉,可用于牡蛎水解液的进一步吸附。     

复合酶法制备葛根多孔淀粉

使用α-淀粉酶与糖化酶复合制备葛根多孔淀粉。通过单因素试验,对多孔淀粉吸油率进行考察,研究其品质特性随加酶量、酶配比、pH值、酶解时间和酶解温度等变化的规律。并由正交试验得出最佳工艺条件,当加酶量0.6%、酶解时间12h、pH5.0、酶解温度50℃、酶质量比(糖化酶:α-淀粉酶)3:1时吸油率最高(60%),且成孔效果良好。     

酶法红薯多孔淀粉的制备

多孔淀粉是一种新型酶变性淀粉,采用α-淀粉酶和糖化酶复合酶解法制备红薯多孔淀粉,对其工艺条件进行研究,当α-淀粉酶∶糖化酶为1∶7(体积比),反应温度45℃,反应时间28 h,pH5.6,加酶浓度0.5%,淀粉浆浓度65%时,可得到吸油率较高的多孔淀粉。     

Optimization of Enzymatic Hydrolysis of Pearlmillet for Glucose Production

Commercial α‐amylase preparation (Biotempase) and crude glucoamylase from Aspergillus sp. NA21 were used to hydrolyse pearlmillet, a non‐conventional starchy substrate. Various concentrations of starch (15—35% w/v) were used for liquefaction; 25% slurry was found to be judicious and optimal. Liquefaction in steam under pressure 2.06—2.75 N/cm², 104—105 °C) was found to be more economical than in a water bath at 95 °C. In the first case a 25% (w/v) slurry was liquefied in 60 min. A pH of 5.0 was found to be optimum for liquefaction. Biotempase dose was cut down by 33% to the prescribed one by addition of 150 ppm CaCl₂ to the slurry. Ninety percent saccharification of liquefied pearlmillet occurred under optimum conditions (24 h and pH 5.0). The optimum temperature for saccharification of pearlmillet was found to be 45 °C. Additions of Ca²⁺, Mg²⁺ and Zn²⁺ were found to have no effect on saccharification. Glucose was found to be the main hydrolysis product as indicated by paper chromatography.     

超声波辅助酶解淀粉制备糊精的工艺研究

以玉米淀粉为原料,采用超声波处理对淀粉乳酶解前进行处理,然后酶解制备糊精,可获得分子分布更为均匀的糊精样品。超声波作用条件为：超声功率50W,超声全程时间范围可选择5～15min,超声波工作时间选择2～5s 范围,间隔时间可选择20s 以上。在此基础上调整加酶量或酶解时间,可获得不同DE 值的糊精样品。通过电镜观察,超声波处理会侵蚀淀粉颗粒表面,造成不同程度的破裂;高强度的超声波降解支链淀粉的作用增强,超声波处理制备的糊精分子分布更为均匀,并且大分子比例减少。     

紫薯淀粉的提取及酶解制糖工艺研究

紫薯的精深加工越来越受到人们的关注,而其中紫薯淀粉作为一种重要的食品原料,现已成为开发应用的主要方向之一.通过系列单因素和正交试验,探索紫薯中淀粉的浸提和中温α[-淀粉酶酶解紫薯淀粉的最佳工艺条件,从而确定紫薯淀粉分离提取及酶解糖化的最佳工艺参数.结果表明,在淀粉分离提取阶段最适条件是浸提温度35℃,浸提时间90 min,紫薯浸提液pH 1.5;在淀粉酶解糖化阶段,采用中温α-淀粉酶对紫薯淀粉进行酶解,酶解温度55℃、酶解时间150 min、加酶量500.1 nkat/g,pH 6.     

响应面法优化柑橘果渣酶解工艺

以柑橘果渣为原料,研究果胶酶和纤维素酶对果渣出汁率的影响。通过单因素试验对影响柑橘果渣酶解出汁率的酶解温度、pH值、酶量、酶解时间四因素进行研究,并通过响应面分析法优化了果渣酶解工艺参数。结果表明:果渣酶解的最佳工艺参数为酶解温度49.17℃、pH4.23、混合酶酶量0.68mg/g、时间3.4h,在此条件下,果渣的出汁率为22.36%。