玉米粉酶法生产葡萄糖浆

直接用玉米粉为原料,酶法生产葡萄糖浆,即不需要把玉米加工成淀粉,而采用玉米去皮,脱胚后磨成粉为原料,经酶水解和糖化后,过滤除渣,然后精制,浓缩而制成葡萄糖浆。此法工艺简单,价格便宜,成本低,缩短了生产周期,该产品与用淀粉生产的产品质量相同,且提高了出糖率。     

双酶法生产谷氨酸发酵用葡萄糖工艺

本文较为详细地介绍了谷氨酸发酵用碳源－葡萄糖的双酶法生产工艺及特点。     

夏秋季节如何防止淀粉与淀粉糖生产过程发酵

今年夏秋季节气候特别炎热，部分淀粉与淀粉糖生产企业不断出现一些不正常现象，如淀粉生产厂出现淀粉发粘、酸度高、有异味、麸质（玉米蛋白）不好沉淀及过滤，玉米油酸度高等；淀粉糖工厂出现糖液贮罐有酒味，特别是母液贮罐及离交系统，结晶过程出现发酵现象，成品糖过滤速度慢等等。这些现象多数都与生产过程发酵有关，现就如何防止淀粉与淀粉糖生产过程发酵提出以下看法，供参考。     

玉米粉生产葡萄糖技术研究

分别用玉米淀粉和玉米粉进行酸酶法和双酶法和双酶法处理制取葡萄糖，对玉米粉替代玉米淀粉进行了经济分析；实验证明采用半湿法玉米粉作为淀粉糖的原料是可行的。采用新工艺技术和酶技术，降低产品成本和提高产品质量是入世后提高国际竞争力的唯一出路。     

氨化预处理对玉米秸秆酶解产糖的影响

为综合利用玉米秸秆,加快纤维素酶降解玉米秸秆。本文以玉米秸秆为原料,还原糖产量为主要指标,通过氨化预处理后酶解玉米秸秆,采用DNS法测定还原糖产量,并考察氨化剂种类、浓度、固含量和氨化时间对玉米秸秆酶解产糖的影响。结果表明,在以碳酸铵为氨化剂,氨化剂浓度为20%,固含量为50%,氨化时间为11 d,在此条件下,还原糖产量最高为314.18 mg/mL,与直接酶解秸秆相比提高51.80%。扫描电镜结果显示,米秸秆经碳酸铵氨化预处理后,木质素和纤维素的结构发生变化,表面结构变得粗糙疏松,纤维素暴露,更有利于纤维素酶的作用。此外,FTIR发现,氨化处理后玉米秸秆在2920和1650 cm^-1处的吸收峰减弱,其峰值降低一定程度上代表木质素结构被破坏。总体来看,玉米秸秆经过碳酸铵氨化预处理后,更有利于酶解玉米秸秆。     

Alkali Extraction of Starch from Corn Flour

The alkali steeping process was tested for extraction of starch from degerminated yellow corn flour. The effect of three process parameters, alkali concentration (0.1 and 0.4%), steep temperature (25 and 55°C) and steep time (30 and 90min) were evaluated for their effect on yield, protein and sodium contents of starch. Two-level full factorial design was used to investigate the process. The experimental results indicated that starch yield increased with increasing steep temperature and at low alkali concentration. All main effects and interactions were found to have significant effect on protein content in the extracted starch. The sodium content of the starch was effected by the three main effects and the three two-factor interaction effects. Conditions were identified that simultaneously produced a high starch yield, low protein and sodium contents were 0.1% alkali steep at 55°C for 30 min.     

玉米淀粉在干脆类食品专用粉生产中的应用

食品加工业需求低面筋、低灰分、高白度的专用面粉。在专用粉生产中利用食用玉米淀粉做出有益的尝试。结果表明,在面粉中添加食用玉米淀粉能有效地降低面筋含量、灰分,提高面粉白度。     

酶促法甜面酱生产工艺条件研究

本实验对酶促法生产甜面酱的工艺条件作了研究。实验表明：采用标准面粉，蒸料水分控制为面粉量的32％～36％，制曲时品温35～38℃、糖化酶O．4％～0．6％、α-淀粉酶0．8％～1％，进行发酵，能使发酵时间缩短一半，产品质量优良。     

Selected Physicochemical Properties of Starch Isolated from Fermented Sorghum Flour

Starch was isolated from fermented sorghum flour (24 h natural lactic acid fermentation), and water retention, starch solubility, clarity of starch pastes and freeze‐thaw stability were measured. In comparison with starch isolated from unfermented sorghum flour, fermentation increased the solubility of the starch and decreased the water retention, but it had no effect on the freeze‐thaw stability of the starch. There was no substantial difference in the starch paste clarity between the two samples. Storage of starch pastes at lower temperature (4°C) resulted in a very low clarity of starch.     

糯玉米粉、淀粉和脱脂淀粉的理化特性研究

以4个糯玉米品种为材料,比较分析了糯玉米粉、淀粉(脱蛋白)和脱脂淀粉(脱蛋白脱脂)的理化特性.结果表现,脱蛋白或脱蛋白脱脂处理不改变材料的结晶类型,各材料均表现为典型的"A"型衍射图谱.理化特性在糯玉米粉、淀粉和脱脂淀粉间存在显著差异.结晶度、膨胀势、回复值、峰值时间和糊化温度以糯玉米粉最高,脱脂淀粉最低;溶解度、峰值黏度和谷值黏度以淀粉最高,米粉最低;透光率以脱脂淀粉最高,米粉最低;但4个糯玉米品种的终值黏度变化趋势不甚明显.     

生物酶修饰对于玉米粉品质的影响

为了改善玉米的加工及食用品质,同时开发生物酶在食品行业应用的新途径。采用枯草芽孢杆菌和黑曲霉分泌的生物酶对玉米粉进行修饰改性,结果表明：经过两种酶修饰后,玉米粉的真蛋白含量、总淀粉含量明显下降,直链淀粉含量、溶解度有所增加,枯草芽孢杆菌胞外酶修饰玉米粉的保水力、凝胶膨胀率和黏度都有所提高,而黑曲霉胞外酶修饰玉米粉的保水力、凝胶膨胀率和黏度都有所降低。在物性测定方面,两种酶修饰后玉米面团的延展性、韧性等都大幅度增加,具有加工面条、水饺等主食品的潜力,说明玉米粉的加工及食用品质得到了明显的改善。     

新疆传统发酵乳制品及酵头中酵母菌的分离鉴定

研究了新疆传统发酵食品中的酵母菌菌群结构及其遗传多样性。采用YPD富集培养后稀释涂布的方法,从12个地区161份样品中分离得到472株酵母菌,通过YPD菌落形态、WL营养培养基聚类分析为16类,挑选不同表型的代表菌株11株进行5.8S-ITS区和26S D1/D2区测序,通过国际核酸数据库分析鉴定菌种。从分离到的472株酵母菌中,共鉴定出6个属8个种,其中包括263株Saccharomyces cerevisiae,156株Issatchenkia orientalis,10株Torulaspora delbrueckii,9株Pichia fermentans,21株Saccharomyces unisporus,7株Metschnikowia pulcherrima,4株Pichia membranifaciens,2株Clavispora lusitaniae,地区优势菌东方伊萨酵母和酿酒酵母。不同基物与不同地区的菌群结构明显不同。上述结果表明新疆的酵母资源具有丰富多样,本研究初次全面地对新疆传统食品的酵母菌群落结构进行分析,为新疆传统食品微生物资源的开发利用,与传统食品的质量控制等奠定了基础。     

Large Scale Preparation of Crystalline Glucose from Raw Starch in Corn Flour

Starch in considerable amount is lost during its purification from raw materials. Further, purification costs energy and time. To avoid these, starch in corn flour was hydrolyzed by the synergistic action of α-amylase and glucoamylase while avoiding high temperature gelatinization and liquefaction processes. When 1600 g (16%, W/W suspension) and 4000 g (40%, WW suspension) corn flour was hydrolyzed and purified, 76.0% and 50.2% glucose yields were obtained. The residues obtained were rich in protein and minerals.