Extraction/oxidation kinetics of low molecular weight compounds in wine brandy resulting from different ageing technologies

This study provides innovative information on the influence of new technologies of ageing (stainless steel tanks with wood staves or wood tablets of chestnut or Limousin oak), in comparison with traditional technology (oak wooden barrels), on the extraction/oxidation kinetics of low molecular weight compounds of wine brandy. The brandy was sampled and analysed by HPLC during the first year of ageing. The results show that most of the compounds tend to increase over the time, but their extraction/oxidation kinetics depend on the ageing technology. The wooden barrels promote greater enrichment in the majority of the compounds. However, gallic acid, ellagic acid and syringaldehyde, and vanillin and 5-methylfurfural, which are strong antioxidants and key-odourant compounds, respectively, present higher contents in the brandy aged with the alternative technologies. Chestnut proves to be a suitable alternative to Limousin oak for the ageing of brandy in all the studied technologies, inducing faster evolution and high quality.     

索氏提取-固相萃取-高效液相色谱法检测烟熏肉制品中苯并(a)芘

采用索氏提取-固相萃取-高效液相色谱法检测清真牛肉香肠中的苯并(a)芘含量,结果表明,该方法操作简单,检测结果准确,可信度高,回收率可以达到91%以上,特别是对于油脂含量较高的食品具有良好的效果,可以推广到其他肉制品中苯并(a)芘的检测。     

蚕豆蛋白提取工艺的研究

对酸、碱提取蚕豆蛋白进行了比较研究.结果表明,碱法提取率可达68%以上,并通过单因素分析,正交试验,优化出最佳提取工艺条件.     

Enzyme assisted extraction of luteolin and apigenin from pigeonpea [Cajanuscajan (L.) Millsp.] leaves

Luteolin and apigenin are naturally occurring flavones with a wide spectrum of pharmacological properties. In the present study, enzyme assisted extraction of luteolin and apigenin from pigeonpea leaves using commercial plant cell wall degrading enzyme preparations including cellulase, beta-glucosidase and pectinase were examined. We found that pectinase offered a better performance in enhancement of the extraction yields of luteolin and apigenin than cellulase and beta-glucosidase. The pectinase assisted extraction process was further optimized by varying different parameters such as pectinase concentration, time of incubation, pH of pectinase solution, and incubation temperature. The optimum parameters were obtained as follows: 0.4 mg/ml pectinase, incubation for 18 h at 30–35 °C, pH of pectinase solution 3.5–4. Under the optimum conditions, the extraction yields of luteolin and apigenin achieved 0.268 and 0.132 mg/g in pectinase treated sample, which increased 248% and 239%, respectively, compared with the untreated ones.     

谷氨酸分离提取工艺进展

谷氨酸提取是味精生产企业的重要课题,本文从L-谷氨酸提取工艺技术出发,结合谷氨酸结晶特性论述了近年来的谷氨酸提取工艺进展及今后的发展方向。此外,随着发酵工艺技术的改进以及谷氨酸高产菌株的培育,尤其是谷氨酸温敏菌株的使用,使得发酵产酸不断提高,因此,适合高产酸发酵液提取的工艺路线已经得到了广大谷氨酸生产企业的青睐。     

亚临界萃取茶籽油的工艺研究

本文以油茶籽为原料,采用新型的亚临界流体技术和分子蒸馏技术相结合的工艺,对制备高品质茶油最佳工艺条件进行研究。以出油率、色泽、苯并芘含量等为考察指标,得出亚临界流体技术的最佳萃取条件为：原料堆密度0.7 kg/L,萃取时间50 min,萃取压力0.5 MPa,温度45℃,萃取率可高达99.12%,与传统压榨工艺相比,提高约15%;分子蒸馏最佳精制条件为：温度160℃,真空度为1.0~2.0 Pa,精制油酸价降为0.22 mg/g,比传统工艺下降70.87%,苯并（α）芘含量则未检出。本研究所得工艺具有快速、环保、成本低和工艺简单的特点,制备的茶油品质达到国家一级油标准。     

玉屏不同油茶种质含油率及油中脂肪酸组成分析

为选育油茶优良无性系,利用核磁共振方法测定了玉屏38个油茶优良无性系的种子和种仁含油率,采用GC-MS/MS方法检测了索氏提取的油茶种仁油脂肪酸组成及相对含量。结果表明:MZ-3、YP-1、6-57、6-48和GY的种子和种仁含油率分别在41%和56%以上。油茶种仁油中检测出6种脂肪酸,分别为棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸和花生烯酸,油酸含量高于83%的品系有5-35、5-37、6-49、XL-210和YP-1。这不仅为玉屏油茶优良无性系的选择提供了科学依据,而且可为油茶籽油的加工利用提供参考。     

索氏法提取柚籽中柠檬苦素工艺优化研究

目的 通过响应面优化得到索氏法提取柚籽中柠檬苦素的最佳工艺。方法 样品粉碎过60目筛, 在一定体积的乙醇水溶液中索氏提取一定时间, 高速冷冻离心机离心得到提取液, 稀释、加样、显色, 在491 nm下测定吸光度, 计算安江香柚籽中柠檬苦素的含量。结果 乙醇浓度、提取时间、液料比对安江香柚籽中柠檬苦素的提取均有显著影响; 响应面优化后的提取工艺为: 乙醇浓度90%、提取时间2.2 h、液料比40:1 (mL/g), 得到柠檬苦素提取率最大值11.36 mg/g。结论 利用索氏法提取安江香柚籽中的柠檬苦素方法可行, 效果明显。     

甘蔗糖厂压榨技术改造湿榨试验查定

主要阐述龙潭糖厂通过湿榨试验检验压榨车间经过技术改造后的生产情况,确定生产过程中各座压榨机出入口、底梳装嵌及压榨效能的实际情况。湿榨试验结论是:压榨机出入口及底梳装嵌合理,压榨效能良好。整列压榨机抽出率为96.17%,且蔗渣水分和糖度逐座降低,蔗渣纤维分逐座增大,末座蔗渣水分、糖度、纤维分分别为47.1%、1.98%、49.54%。     

从马齿苋中提取叶蛋白工艺的研究

采用酸法及加热法，分析了从马齿苋中提取叶蛋白的工艺条件。结果表明：从马齿苋中提取叶蛋白工艺的最佳条件：加热时间为9min，加热温度为75℃，盐酸调pH值为3，液料比为4；该工艺提取叶蛋白的提取率为0.95％，叶蛋白的沉淀率为20.02％。