Application of high density steam flash-explosion in protein extraction of soybean meal

The high density steam flash-explosion (HDSFE) was used to extract protein from soybean meal. Soybean meal samples were treated at 1.3 MPa and 1.8 MPa for 60 s, 120 s and 180 s, respectively. After HDSFE treatment at 1.8 MPa for 180 s, the extraction yield of protein was increased from 50.50% to 65.66% compared with untreated soybean meal. The emulsification properties and fat-binding capacity of soy protein isolate (SPI) extracted from soybean meal treated by HDSFE were all improved compared with SPI extracted from untreated soybean meal and white flakes. Molecular weight distribution analysis of SPI showed that after HDSFE treatment the peak with molecular weight about 504 kDa and 43.3 kDa disappeared and the peak with molecular weight about 669 kDa increased indicating protein aggregation. Gel electrophoresis showed that high molecular weight aggregates of protein have been formed by covalent bond.     

Physicochemical Characterization of a Heat Treated Calcium Alginate Dry Film Prepared with Chicken Stock

Solid sodium alginate was dissolved into chicken stock in order to give a final alginate concentration of 0.9 percent (w/v). Calcium ions present in chicken stock were enough to induce ionic gelation. After drying, Fourier transform infrared spectroscopy, thickness and mechanical properties of films obtained were determined. Calcium alginate‐chicken stock films were heated at 130 °C for different times between 0 and 15 min. Mechanical and optical studies, differential scanning calorimetry, visual aspect and scanning electron microscopy were carried out to describe physicochemical properties of heat treated films. Heating developed a maroon ochre color and increased the brittleness (crispness) of the films related to the intensity of the treatment. Differential scanning thermometry and study on appearance of the films suggested that Maillard reactions may be responsible for the observed changes. Maillard reactions mainly occurred between reducing sugar monomers and free amino groups of gelatin peptides present in the chicken stock, and between alginate and gelatin peptides to a lesser extent. In addition, the plasticizing effect of fat added with chicken stock was also studied. These studies suggest a potential use of heat treated chicken stock films as a substitute of roasted chicken skin.     

聚合磷硫酸铁制备及净化含铅废水的试验研究

以钛白粉副产品绿矾为主要原料,氯酸钠作氧化剂,调节亚铁离子与硫酸根离子之间摩尔比后微波作用仅几分钟就能合成出液体聚合硫酸铁,并在此基础上加入磷酸根离子可得到所需絮凝剂--聚合磷硫酸铁;试验了该絮凝剂最佳合成工艺条件;采用该试剂净化含铅废水,取得了较好去除效果,并且探讨了除铅最佳试验条件.     

微波消解-电感耦合等离子体质谱法测定高钙基体中As、Pb、Cu、Cd

研究溶液中高钙基体效应及降低基体干扰的方法,建立微波消解一电感耦合等离子体质谱法9n,4定高钙基体中As、Pb、cu、cd含量的分析方法。样品采用微波消解,通过研究功率和载气流速在不同钙基体含量时对As、Pb、cu、Cd测定的影响,结合调谐液优化仪器工作参数,选择合适的内标元素对钙基体干扰进行校正。结果：高钙基体中钙基体含量在不超过0．1％,90rain内连续进样引起的基体干扰基本上得到克服。各元素加标回收率均在89％～104％,标准偏差均低于4．0％。方法准确可靠,适用于高钙基体中As、Pb、Cu、Cd含量的同时测定。     

ICP-OES法和离子色谱法测定水中钙、镁比对研究

目的:对ICP-OES法和离子色谱法测定水中钙、镁两种元素方法进行比对研究。方法:分别采用ICP-OES法和离子色谱法对不同水源10个水样进行比对测定。结果:两种方法灵敏度、准确度、精密度相当,但ICP-OES分析速度较离子色谱提高10倍。结论:ICP-OES法和离子色谱法均适用于水样中微量、常量钙、镁含量的测定,但ICP-OES法分析速度快,且具有多元素同测的特点,更适合于批量样品分析。     

纸浆漂白用二氧化氯制备工艺酸性芒硝处理技术

介绍了纸浆漂白用二氧化氯制备工艺酸性芒硝处理技术的原理、工艺流程及工艺条件的选择,从物料消耗、副产品生成及经济效益上进行了分析,表明与R8法二氧化氯制备装置相比,中性芒硝法工艺更值得推广应用。     

氯化钙处理对鲜切芹菜生理与品质的影响

目的研究不同浓度的氯化钙处理对室温下贮藏的鲜切芹菜生理品质的影响。方法分别采用化学滴定法、紫外分光光度法、称重法分析测定了鲜切芹菜可滴定酸、可溶性蛋白、还原糖、总糖、Vc、失重率等多项生理生化指标。结果芹菜经切割后在室温贮藏期间,可滴定酸、可溶性蛋白、还原糖、总糖、Vc含量呈现前期上升后期下降的趋势,失重率随贮藏期的延长逐渐上升;较低浓度氯化钙处理的可滴定酸、还原糖、总糖、Vc含量明显地高于对照和其他处理组,可溶性蛋白含量、失重率却低于对照组。结论氯化钙处理有效地保持了鲜切芹菜良好的生理品质,是一种简单、安全、有效的果蔬保鲜方法。     

海藻酸钙固定化细胞及其在食品工业中的应用

综述了海藻酸钙的性质、固定化细胞的制备方法,稳定性及在食品工业中的应用。     

市售商品补钙制剂的补钙效果观察

本文以大鼠为模型，研究不同化学形式钙以及市售数种钙剂的补钙效果。１．不同化学形式钙的补钙效果：选用三周龄断乳Ｗｉｓｔａｒ大鼠５６只，雌雄各半，喂饲３周缺钙饲料后，按体重随机把大鼠分成４组，即缺钙饲料、补充碳酸钙、活性钙或乳酸钙饲料（３０００ｍｇＣａ／ｋｇ），实验期为１２周。２．市售补钙制剂的补钙效果：选用动物及实验期同实验１，动物数为８４只，按体重随机把大鼠分成７组，即缺钙饲料组，其它６组为补充碳酸钙、钙尔奇－Ｄ、盖天力、活性钙、壮骨宝、巨人补钙饲料（３０００ｍｇＣａ／ｋｇ）。补钙各组大鼠终体重和身长均非常显著高于对照组。补充不同化学形式钙或商品钙制剂组的血浆、红细胞和肝脏中钙含量均显著高于缺钙对照组，补钙各组间无显著差异。多数钙制剂对雄性肾脏钙存留的影响不显著，只有盖天力显著增加雄性肾脏钙存留；补钙对雌性肾脏钙存留的影响非常显著。补充的三种化学形式钙和商品钙剂均显著增加骨矿物质含量，但是碳酸钙和乳酸钙的效果优于活性钙，巨人补钙和活性钙的效果似不如其它钙制剂。按效果价格比，目前碳酸钙仍是最好的钙源。