New Process for Extracting Oil and Starch from Tea Seeds

A new process for extracting oil and starch from tea seed was introduced. The new process included one special link compared with all of the processes used now for tea seed oil and starch production. The link was static fermentation by which oil bodies and starch were separated naturally from tea seeds. By the process, tea seed oil and starch which were in conformity with government standards about edible oil and starch were successfully produced with 16% and 8% of production rate, respectively. The new process has many advantages, such as more simple equipments, lower production cost and whole natural products, etc..     

HPLC法检测生物硒醋及老陈醋乳酸和醋酸含量

本文研究了利用HPLC法测定生物硒醋和老陈醋中乳酸和醋酸的含量,并对其测定条件进行优化。应用以C18为色谱分析柱,检测波长为215 nm,流动相为2.5%NH4H2PO4缓冲液,样品稀释度为30倍,流速为1.0 min/m L,柱温为29℃,生物硒醋样品的最佳p H=2.5,老陈醋的最佳p H为2.7时,可以较好的分离、检测生物硒醋和老陈醋中乳酸和醋酸的含量,所有的检测在4 min内完成。同时当其他分析条件一定,p H=2.7时,醋酸和乳酸标样的回归方程分别为y=484.23x-81.373,R²=0.9992、y=441.37x-68.321,R²=0.9979。当p H=2.5时,醋酸和乳酸标样的回归方程分别为y=484.61x+72.201,R²=0.9993、y=389.82x+30.432,R²=0.9991。该检测方法重复性、准确度、精确度的相对标准偏差范围为0.00%¹.07%,其中生物硒醋乳酸和醋酸标品的加标回收率分别为100.00%¹10.00%、99.00%¹00.83%,老陈醋乳酸和醋酸标品的加标回收率分别为100.00%¹01.00%、100.00%¹10.00%。此方法重复性好、准确性和精确性好,检测时间短。可以应用于生物硒醋和老陈醋的HPLC法有机酸的定量分析。      

油茶壳中总黄酮的最佳提取工艺研究

对油茶壳中总黄酮类物质的乙醇提取工艺进行了研究,探讨了影响提取率的主要因素,最后通过正交试验确定了最佳提取工艺,结果表明:在30倍于样重的60%的乙醇浸泡后,40℃下超声波辅助萃取45min,连续提取2次,黄酮的总浸出率可达97.34%,油茶壳中的黄酮溶出量为1.709%.     

Chemical composition, angiotensin-converting enzyme-inhibitory activity and antioxidant activities of few-flower wild rice (Zizania latifolia Turcz.)

BACKGROUND: The chemical compositions of the stem and leaf sheath of few‐flower wild rice were analysed. In addition, their extracts were evaluated for diphenylpicrylhydrazyl (DPPH) free radical‐scavenging activity, ferric‐reducing antioxidant power and angiotensin‐converting enzyme (ACE)‐inhibitory activity, since these are important properties of sources of nutraceuticals or functional foods. RESULTS: The stems contained more ascorbic acid (0.06 g kg^?1 fresh weight), protein (28.18 g kg^?1 dry weight (DW)), reducing sugars (308.54 g kg^?1 DW), water‐soluble pectin (20.63 g kg^?1 DW), Na₂CO₃‐soluble pectin (44.14 g kg^?1 DW), K (8 g kg^?1 dry matter (DM), S (6 g kg^?1 DM) and P (5 g kg^?1 DM) but less starch, total dietary fibre, Si, Na and Ca than the leaf sheaths. The DPPH free radical‐scavenging IC₅₀ values of the stem and leaf sheath extracts were 19.28 and 21.22 mg mL^?1 respectively. In addition, the ACE‐inhibitory IC₅₀ value of the stem extracts was 38.54 mg mL^?1. CONCLUSION: Both the stem and leaf sheath extracts exhibited good antioxidant properties, while good ACE‐inhibitory activity was detected only in the phosphate buffer solution extracts of the stem. Few‐flower wild rice could be processed into formula feeds for fish, poultry, etc. or functional foods for persons with high blood pressure. Copyright © 2011 Society of Chemical Industry     

Evaluation of the quality of deep frying oils with Fourier transform near-infrared and mid-infrared spectroscopy

Deep frying oils are subjected to high temperature and prolonged heating that may lead to a series of quality and safety problems for fried foods. This study evaluated the quality of deep frying oils collected from a local college canteen (n = 132) with Fourier transform mid-infrared (FT-IR) and Fourier transform near-infrared (FT-NIR) spectroscopy. Partial least squares (PLS) regression was used to correlate spectral data with free fatty acids (FFA) and peroxide (PO) values of frying oils. The coefficient of determination (R(2)), standard error of prediction (SEP), and the RPD (ratio of the standard deviation of data set to the SEP) were used as indicators for the predictability of the PLS models. The FT-IR and FT-NIR methods exhibited similar predictability for the FFA values (FT-IR: R(2) = 0.954, SEP = 0.14, RPD = 4.48; FT-NIR: R(2) = 0.948, SEP = 0.14, RPD = 4.38). Although the predictability of the FT-IR method for the PO values was not as satisfactory as that of the FT-NIR method (FT-IR: R(2) = 0.893, SEP = 6.17, RPD = 2.93; FT-NIR: R(2) = 0.953, SEP = 4.15, RPD = 4.36), both FT-IR and FT-NIR methods could be used as simple and rapid approaches to determining the quality of deep frying oils.     

天河石的颜色成因探讨

在充分查阅了大量前人的资料的基础上,对5个天河石样品进行常规宝石学测试,并借助大型仪器对其进行深入的研究。激光剥蚀电感耦合等离子体技术测试发现,天河石的微量元素Fe、Rb和Pb的质量分数较多;显微红外光谱对结构水测试发现,在3 800~3 200cm~(-1)范围内显示有结构水和液态水的吸收;显微紫外-可见吸收光谱测试显示以380、625、740nm为中心的强吸收。观察讨论天河石对可见光的吸收,结合热处理和辐照处理的结果,综合比较前人的研究结果,得出影响天河石颜色的三个吸收区域(625nm中心、740nm中心和380nm中心)都是空穴缺陷造成的,与结构水并无直接的关系。     

烟草秸秆低聚木糖的制备和纯化

为优化烟草秸秆低聚木糖制备参数,采用碱解方法提取木聚糖、酶解法制备低聚木糖以及单因素实验法考察了常见因素对工艺的影响。结果表明,木聚糖提取条件为：2.000 g秸秆粉末（≤100目）浸没于20.00 mL浓度为24% NaOH（m/V）和1% NaBH₄（m/V）碱液中,70 ℃条件下浸提4 h,滤液加3倍乙醇体积用量进行醇沉以及0.2倍乙酸体积用量进行中和。制备低聚木糖的条件为：溶液pH为5.50,温度40 ℃,时间6 h,木聚糖溶液（20 mg/mL）10 mL,木聚糖酶液（0.6%,m/V,4.1 U/mL）20 mL。低聚木糖分离提纯条件为：阳离子树脂柱分离纯化,填充高度18.0 cm、直径为4.5 cm;纯化液用高效液相色谱进行定性定量分析。通过上述方法得到的低聚木糖产品纯度较高,对工业制备低聚木糖工艺优化有一定的参考价值。     

Influences of Operating Parameters on the Formation of Furan During Heating Based on Models of Polyunsaturated Fatty Acids

Furan, a possible carcinogen, is commonly produced by thermal processing in a number of heated foods. The existence of furan levels in foods has attracted considerable attention worldwide. Recent research of furan in food has focused on the possible influences of operating parameters on the furan formation during heat processing. The aim of our study was to investigate the impacts of multiple factors (pH, temperature, heating time, ferric, and glutamic acid) on furan formation using linolenic and linoleic acids‐based model systems in which furan was analyzed by headspace gas chromatography–mass spectrometry (HS‐GC–MS). The results revealed that the content of furan increased rapidly when the heating temperature was elevated, with the highest levels of furan in neutral buffer solutions, the furan levels were also found to be related to heating time in all model systems. Ferric promoted furan formation from polyunsaturated fatty acids, conversely glutamic acid with an optimum concentration suppressed the furan formation. The minimal level of furan in foods during thermal treatment could be achieved via adding furan formation suppressors, and/or avoidance of furan forming promoter.     

单增李斯特菌在生食鱼片中生长模型的建立

为研究生食鱼片中单增李斯特菌的生长规律,将单增李斯特菌接种到经冷杀菌后的3 种生食鱼片（三文鱼片、金枪鱼片、鲷鱼片）中,分别置于4、8、15、25、35 ℃环境下培养,间隔适当时间取出计数。用5 种常用的一级模型（Gompertz模型、Baranyi模型、Logistic模型、Richards模型和MMF模型）对实验数据进行拟合,通过比较相关系数R2和均方误差（mean square error,MSE）,确定最适一级模型为Gompertz模型。建立单增李斯特菌生长动力学参数（最大比生长速率μm和迟滞期λ）关于温度、pH值和水分活度的二级平方根扩展模型,并应用相关系数R2、偏差值Bf和准确值Af进行验证。结果表明,构建的二级模型能够很好地描述生食鱼片中单增李斯特菌的生长情况。     

2010中国国际网印及数字化印刷展

由中国印刷技术协会和中国网印及制像协会共同主办的2010中国国际网印及数字化印刷展／2010中国国际纺织品印花展／2010中国（广州）标签印刷技术展将于2010年12月2—4日在广州·琶洲·保利世贸博览馆（广州市海珠区新港东路1000号）举行。本届展会将以“绿色环保、自主创新”为主题,