Nondestructive determination of soluble solids content and pH in tomato juice using NIR transmittance spectroscopy

The potential of near-infrared (NIR) transmittance spectroscopy to nondestructively detect soluble solids content (SSC) and pH in tomato juices was investigated. A total of 200 tomato juice samples were used for NIR spectroscopy analysis at 800–2400 nm using an FT-NIR spectrometer. Multiplicative signal correction (MSC), and the first and second derivative were applied for pre-processing spectral data. The relationship between SSC, pH, and FT-NIR spectra of tomato juice were analyzed via partial least-squares (PLS) regression. PLS regression models were able to predict SSC and pH in tomato juices. The r _c, RMSEC, RMSEP, and RMSECV for SSC were 0.92, 0.0703°Brix, 0.150°Brix, and 0.138°Brix, respectively, whereas those values for pH were 0.90, 0.0333, 0.0316, and 0.0489, respectively. It is concluded that the combination of NIR transmittance spectroscopy and PLS methods can be used to provide a technique of convenient, versatile, and rapid analysis for SSC and pH in tomato juices.     

大豆活性肽抗氧化力与其分子量关系的研究

大豆活性肽具有抗氧化性,其抗氧化力大小与大豆活性肽的分子量有关。采用凝胶柱层析分离法对碱性蛋白酶所制备的大豆活性肽(水解度为19.5%)进行分离纯化,得到六个组分,然后比较六个大豆活性肽组分(浓度均为1mg/mL)的抗氧化力大小,结果表明,组分4的抗氧化效果最好。用电喷雾质谱(ESI-MS)测定抗氧化大豆肽组分4的分子量,根据质谱图采用电喷雾质谱软件分析得出,抗氧化大豆肽组分4的平均分子量500,氨基酸数目为4个。     

棕棉混纺针织纱的工艺实践

探讨棕棉混纺针织纱的纺纱工艺.针对棕棉和有机棉的不同性能特点,确定合理的纺纱方案,在纺纱各工序采取一系列工艺技术措施,采用并条混和的工艺路线,通过优化工艺、严格控制好各工序温湿度,最终顺利生产出棕棉/长绒棉/有机棉40/35/25 14.6 tex混纺针织纱,满足了针织纱的使用要求.     

论家具企业质量管理中人的因素及其作用

人的因素在家具质量管理工作中有着举足轻重的作用,各个层次的工作者有着不同的质量职责,发挥不同的作用。本文立足人的因素来解析企业质量管理体系中各层工作者的质量工作,及对质量管理体系运行的作用。     

家具绿色设计中的原材料选择

在国际上一致倡导注重资源和原材料再生利用的呼声中,按“绿色造材”概念设计家具,改变人们现有审美观念,使自然能源利用和审美景观的创造都达到新的高度。在这种设计创新氛围中,现代家具设计应在环境型原材料和绿色科学技术方面多加创新和运用,使绿色生态成为一种新的生活追求。就家具原材料而言,定义了“绿色”原材料的概念,描述了生态原材料的现状以及发展前景,指出了“绿色”设计中原材料的选择对最终家具“绿色程度”具有重要意义。     

臭氧漂白的研究和应用

臭氧作为无氯漂白的主力军，经过许多年的研究开发之后，今已在实际中得到应用。文中介绍了臭氧漂白中间试验和工业生产的实例以及所取得的经验，臭氧漂白的工艺和特点，臭氧漂白的热点──臭氧漂白中碳水化合物的保护和降低能耗等方面的最新研究成果。     

响应面法优化豆豉蛋白酶解工艺

以豆豉蛋白为原料,选用木瓜蛋白酶与复合风味酶分步水解制备豆豉蛋白水解物。通过单因素试验和响应面分析,确定了木瓜蛋白酶的水解条件为:反应温度62.93℃、pH7.49、酶/底物4.91%、底物浓度5.48%,在此条件下水解5h;木瓜蛋白酶水解液再加入复合风味酶酶解,优化的水解条件为:在pH6.0,酶/底物为3%,55℃条件下反应3h,豆豉蛋白最终水解度达到28.37%。     

对胶版印刷纸掉毛的探讨

综述了对胶版印刷纸掉毛的研究以及在工业用印刷机上研究纸张掉毛的实验方法,重点分析了工业用胶印橡皮布上图文部分比非图文部分掉毛少的原因。     

Development of an assay for rapid identification of meat from yak and cattle using polymerase chain reaction technique

Yak meat is of good quality with fine texture, high protein and low fat content, and rich in amino acids compared with that of cattle, and it lacks anabolic steroids or other drugs. In general terms, however, the meat yield of yak is relatively low compared with that of the cattle. In order to prevent possible adulteration of yak meat with cattle meat, based on the sequence of mitochondrial 12S rRNA gene, a multiplex PCR-based approach was proposed for rapid identification of the meat from yak and cattle using three primers designed in this work. Through the combinatorial usage of three primers with a single reaction set, two fragments of 290 and 159 bp were amplified from the cattle meat DNA, whereas only a fragment of 290 bp was obtained from the yak meat DNA. Using the assay described, satisfactory amplification was accomplished in the analysis of raw and heat-treated binary meat mixtures of yak/cattle with a detection limit of 0.1% for cattle meat. The technique is fast and straightforward. It might be a useful tool in the quality control of yak meat and meat products.     

纳豆芽孢杆菌固态发酵培养基的优化

为优化纳豆芽孢杆菌固态发酵培养基,采用微生物固态发酵技术,以固态发酵后的活茵数、芽孢教、蛋白酶及α-淀粉酶活力为指标,对纳豆芽孢杆茵固态发酵培养基组成及配比,添加碳源、氮源种类及浓度,培养基的含水量进行优化研究.试验结果表明,在玉米粉与麦麸配比3:7、葡萄糖2%、硝酸铵0.5%、本60%条件下发酵效果最好.