羟丙基-β-环糊精对虾青素稳定性的影响

以羟丙基-β-环糊精为壁材,制备了羟丙基-β-环糊精/虾青素包含物,并对其稳定性进行了研究。热重/差热联用分析表明,复合物的形成将虾青素的热分解开始温度至少提高了40℃,达到290℃左右。光热稳定性实验显示,包埋有利于提高虾青素在环境中的稳定性,并且具有很好的缓释效果。经羟丙基-β-环糊精包埋后,复合物比原虾青素具有更高的稳定性。     

聚氨酯涂层剂的应用性能

为探讨聚氨酯应用性能与其物理、化学结构及组成的关系,制备了3组具有不同结构及组成的亲水性聚氨酯涂层材料。测试了涂层织物的防水性、透湿性等主要应用性能;选用广角X衍射仪(WAXD)及表面张力/接触角测定仪研究了材料的聚集态结构及其表面性能。研究结果表明:涂层织物的透湿性及防水性主要取决于聚氨酯涂层材料中亲水性醚键的含量以及硬链段与软链段的比例。     

响应面法优化羟丙基-β-环糊精制备工艺

对β-环糊精碱性条件下与环氧丙烷反应制备羟丙基-β-环糊精的工艺进行了优化。通过单因素试验确定了反应温度、反应时间和透析时间三个试验因素的取值范围，并用响应面分析法确定了最佳工艺参数：反应时间16．05h，反应温度31．06℃，透析时间7．41h。据此工艺参数制得羟丙基-β-环糊精的取代度达到4．10，得率61．80％。     

真空油炸胡萝卜脆片基本特性的研究

真空油炸技术可用于生产高品质的果蔬脆片．主要研究了油炸温度和真空度对胡萝卜片水分质量分数、脂肪质量分数、色泽及质构的影响．试验表明：随着油炸温度和真空度的升高，其干燥和脂肪吸收速度相应提高，且两者呈一定的相关性．统计分析可知：油炸温度和真空度并不显著性影响脆片的白度（L）、红度（a）、黄度（b）值（P〉0．05）；对于脆片的破碎力而言，真空度具有显著性影响（P〈O．05），而油炸温度不具有显著性影响（P〉0．05）．     

聚丙烯酰胺凝胶电泳研究猪血清蛋白硫酸铵分级盐析

本文通过聚丙烯酰胺凝胶电泳研究了盐析时各种猪血清蛋白溶解度与硫酸铵饱和度的关系,结果显示猪血清蛋白析出区间为25%～70%硫酸铵饱和度,各种猪血清蛋白具有各自的沉淀区间。10倍稀释猪血清白蛋白最佳硫酸铵沉淀方案为:pH值7.4,调节硫酸铵饱和度到50%,离心除去沉淀,调清液pH值至4.5,硫酸铵饱和度至55%,沉淀白蛋白。pH值7.4,35%饱和度硫酸铵沉淀猪血清时,IgG得率为69.5%,纯度为76%;40%饱和度时,IgG得率为91.8%,纯度为61.6%。     

普鲁兰酶产生菌的分离与鉴定

以淀粉工业用普鲁兰酶的开发为目的，采集全国不同地区的土壤样本，分离其中的嗜中温细菌，经过形态学鉴定后，通过16SrDNA最终确定其属种并建立细菌库。对该细菌库中短短芽胞杆菌所产普鲁兰酶进行了初步的酶学研究，研究表明野生短短芽胞杆菌的初始酶活都很低，有几株其初始产酶水平大于1U／mL。酶学性质研究表明，短短芽胞杆菌普鲁兰酶有较好的应用价值，其最适作用pH在4～6之间，最适作用温度在50℃～60℃之间，其中来源于CICIM B1490的普鲁兰酶，其酶学性质与目前使用黑曲霉糖化酶的酶学性质相似，能够作为以后研究的初发菌株。     

FORMATION OF TASTE AND ODOR COMPOUNDS DURING PREPARATION OF DOUCHIBA, A CHINESE TRADITIONAL SOY-FERMENTED APPETIZER

Douchiba (DCB), a Chinese traditional soy‐fermented appetizer, is abundantly produced and widely consumed in Guizhou province of southwest China. In this study, an analysis of free amino acid (FAA) profiles, low‐molecular weight peptide fractions (LMWPFs), hydrophobic bitter peptide fractions (HBPFs) and volatile compounds was conducted to understand the changes in taste and odor compounds of DCB during five consecutive manufacturing stages: steamed soybean (SS), 5‐day incubated Koji (Koji), 6‐month fermented Douchi, semifinished Douchiba (sm‐DCB) and 6‐month ripened finished Douchiba (DCB). The total free amino acids (TFAAs) increased significantly from SS to DCB by about 11 times and amounted to 20.1% of the crude protein. Arg, Glu, Phe, Leu and Lys were the most abundant FAA at the end of ripening, and were 64.6% of TFAA. The most abundant taste active FAA classes were the bitter FAA, representing eight‐ and threefold increases over sweet and MSG‐like FAA, respectively. The final values of all bitter and monosodium glutamate‐like (MSG‐like) FAA at DCB stage were significantly higher than their respective thresholds. The ratio of oligopeptides (500～1000 Da) accounted for 13.8 and 2.5% of LMWPF and HBPF, respectively. However, the taste of DCB was predominated by saltiness, followed by moderate “umami” taste and slight bitterness, likely as a result of the balance and interaction among different taste components. A total of 122 volatile compounds were identified, including alcohols, acids, esters, aldehydes, ketones, phenols, sulfur‐containing compounds, heterocyclic compounds, alkines, benzenes and spice aromatics. The subtle aroma of the finished DCB seemed to depend not only on particular key compounds but also on a “critical balance” or a “weighted concentration ratio” of 60 compounds. These volatile compounds, mainly derived from lipid oxidation, amino acid degradation, carbohydrate fermentation, Maillard reaction and Strecker degradation during the microbial metabolism, enzymatic catalysis and spontaneous reactions.     

Rapid determination of 19 quinolone residues in spiked fish and pig muscle by high-performance liquid chromatography (HPLC) tandem mass spectrometry

A multiresidue method has been developed for the confirmation and quantification of 19 quinolones (enrofloxacin, ciprofloxacin, norfloxacin, ofloxacin, flumequine, oxolinic acid, difloxacin, sarafloxacin, sparfloxacin, danofloxacin, fleroxacin, marbofloxacin, enoxacin, orbifloxacin, pefloxacin, nalidixic acid, pipemidic acid, lomefloxacin and cinoacin) in pig and fish by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with acetonitrile, analytes separated by LC on a C₁₈ column using 0.1% formic acid–methanol with a linear gradient elution programme, and detected by MS/MS. The linear range was 0.3–50 µg kg^–1 with correlation coefficients (r) more than 0.9956. The limits of detection were 0.1 µg kg^–1. Mean recoveries for each analyte in pig muscle and fish ranged from 75.3% to 96.3% and from 79.7% to 94.2% with relative standard deviations below 10%. The method is fast, safe, sensitive and precise, and can be used simultaneously to analyse residual quinolones.     

诱导条件下营养因子对粗糙脉孢菌合成漆酶的影响

研究了粗糙脉孢菌合成漆酶的一些重要影响因素，包括诱导剂种类、碳源、氮源。获得了粗糙脉孢菌合成漆酶的较适宜每件：以20g／L葡萄糖为碳源，2g／L硝酸铵为氮源，粗糙脉孢菌静止培养2-3d后，再加入放线菌酮（终浓度2．8μmol／L）诱导培养6—7d后产生的漆酶的最高酶活可达4-5u／mL。     

粮油食品中真菌毒素的LC-MS法检测

粮油食品中常见的真菌毒素有:黄曲霉毒素、赭(棕)曲霉毒素、展青霉毒素、玉米赤霉烯酮、串珠镰刀菌毒素及脱氧雪腐镰刀菌烯醇等,因含量较低,用常规方法检测不出来。用LC-MS检测,灵敏度高、前处理比较简单,结果准确可靠,在检测食品中真菌毒素上前景广阔。