苹果籽油搅拌提取的工艺优化

探讨了苹果籽油的石油醚提取技术,建立了提取工艺的人工神经网络模型,研究了工艺模型的遗传算法优化技术。结果表明:影响苹果籽油提取得率的因素有温度,时间,液料比,搅拌转速;神经网络结构为4—5—1的模型能较为精确地拟合输入的样本数据,其对测试样本的输出值与试验结果的相关系数为0.988;遗传算法优化出的最佳工艺参数为温度59.8℃、时间2.5 h、液料比11.9:1(mL:g)、搅拌转速1 107 r/min,该工艺参数下苹果籽油得率明显大于单因素和二次组合试验的结果,比最好的提高了11.8%。用神经网络模型描述提取工艺参数与提取得率之间的关系,用遗传算法优化,能设计出最佳的提取工艺参数。     

遗传算法结合反向传播算法神经网络优化党参多糖的提取工艺

目的 通过遗传算法结合BP(Back Propagation)神经网络,与正交试验结果作对比,优化党参中粗多糖的提取工艺。方法 以党参多糖的提取得率为指标,采用三因素(提取次数、提取时间、料液比)优化BP神经网络模型参数,并建立网络模型,再利用遗传算法对网络进行目标寻优,获得党参多糖的最佳提取工艺。结果 得到的最优提取工艺为提取次数3次,提取时间2 h,加水量为10倍,在此条件下党参多糖得率预测值为55.29 mg/g,和实际测量值的相对误差仅为1.10% ,具有较好的网络预测性。本方法无需复杂的实验过程,就可以快速得到最优的提取条件,且所得的党参多糖提取率较正交试验最优工艺所得的党参多糖提取率高出5.42%。结论 利用遗传算法结合BP神经网络算法对党参提取粗多糖的提取工艺进行优化快速、高效、可行。     

基于人工神经网络的黑米花色苷提取的研究

目的:建立黑米花色苷提取的人工神经网络模型,得到最佳提取工艺参数。方法:正交实验与人工神经网络相结合,利用正交实验获得的数据作为神经网络的训练样本,建立输入为实验因素参数,输出为花色苷提取率的神经网络模型;采用人工神经网络模拟和预测黑米花色苷提取的最佳条件和提取率。结果:黑米花色苷最佳提取条件,提取液乙醇/水/盐酸体积比为55:45:0.5,温度50℃,固液比为1:10(g/mL),提取时间为1h,提取次数为4次。结论:人工神经网络模型准确预测花色苷提取率,且得到最佳提取条件下花色苷提取率为3.944%,高于正交实验的3.740%,将神经网络与正交实验结合用于实验条件优化可以缩短优化实验参数的时间,获得比正交实验更优化的实验条件。     

苹果籽油的乳化及工艺参数优化研究

探讨苹果籽油的乳化工艺,建立乳化工艺的人工神经网络模型,研究工艺模型的遗传算法优化技术。结果表明：影响乳化稳定性的因素有乳化剂的配比、壁材用量、壁材比、乳化剂量、乳化温度及乳化时间;神经网络结构为4—9．1的模型能较为精确地拟合输入的样本数据,其对测试样本的输出值与试验结果的相关系数为0．988;遗传算法优化出的最佳工艺参数为壁材含量5％、乳化剂量0．59％、温度58℃、时间13min,该工艺参数下乳化稳定性明显大于单因素和二次组合试验的结果,比最好的大12．1％。用神经网络模型描述乳化工艺参数与乳化稳定性之间的关系,用遗传算法优化,能设计出最佳的乳化工艺参数。     

苹果多糖提取的优化工艺研究

分别采用碱提、酸提和酶提的单级提取法和各法结合的多级提取法,从苹果渣中提取苹果多糖,通过正交实验等优化各提取方法的工艺参数,结果表明,碱提法优化工艺为:4mol/L NaOH溶液,70℃浸提1h;酸提法优化工艺为:pH2.3,100℃提取3h;酶提法时,采用复合酶组合比单一酶作用提取率高,最佳复合酶组合为:先加3%复合果胶酶,再加3%纤维素酶,最后加入5%α-淀粉酶,每次加新酶后于50℃保温2h.采用优化工艺对苹果多糖进行分级提取,结果比各一步提取法的多糖产率都高,可以有效地提高苹果渣的利用率.     

基于遗传算法-神经网络及响应面法优化龙牙百合总黄酮提取工艺

在单因素试验基础上,采用Box-Behnken 设计响应面和遗传算法-神经网络两种方式对龙牙百合总黄酮提取工艺条件进行优化。结果表明：各因素对提取结果均呈现先上升后下降的趋势,响应面法和遗传算法-神经网络模型法相对误差和决定系数R2 分别为1.19%、0.955 4 和0.72%、0.994 7。经验证,遗传算法-神经网络模型优化结果高于响应面,表明前者具有更强优化能力。最终采用遗传算法-神经网络优化获得提取龙牙百合总黄酮最佳工艺条件为：提取温度73 ℃、提取时间50 min、液固比43∶1（mL/g）、乙醇体积分数53%,在此条件下总黄酮含量为47.17 mg/g,高于响应面预测值46.63 mg/g。     

纤维素酶提取苹果渣黄酮及抗氧化研究

研究了纤维素酶提取苹果渣黄酮的工艺条件及抗氧化活性。结果表明,与传统化学法相比,纤维素酶法提取苹果渣黄酮较好,黄酮提取率从0.43%提高到0.56%。对酶法提取工艺进行优化,得到最佳工艺条件为:纤维素酶浓度0.2%,pH=5.2,酶解温度60℃,酶解时间40min。在最佳条件下,纤维素酶法所得黄酮的提取率可达到1.26%,为化学法黄酮提取率的2.93倍。并对提取的黄酮进行羟自由基清除实验,发现酶法与化学法提取黄酮的成分清除能力相似,表明两种方法提取黄酮物质结构可能一样。     

基于遗传神经网络的水解米渣制备小肽工艺优化

提出了一种神经网络与遗传算法相结合的水解米渣制备小肽工艺参数优化方法.以试验数据为样本,通过神经网络建立水解工艺参数与水解度关系之间的复杂模型,利用遗传算法对酶解工艺参数进行优化,充分发挥神经网络的非线性映射能力和遗传算法全局寻优能力.仿真实验显示了方法的有效性和优越性.     

低共熔溶剂法提取枣渣中黄酮类物质

目的 得到采用低共熔溶剂提取枣渣黄酮的最佳提取工艺。方法 以冬枣枣渣中的黄酮提取率为评价指标，在低共熔溶剂的种类、摩尔比、料液比、超声时间、超声温度、超声功率等单因素实验基础上，采用BBK实验模型对提取工艺进行优化。结果 最佳提取条件为：以氯化胆碱-丙三醇-乙醇（摩尔比1:1:1）为提取剂，在料液比1:60，超声功率105W，温度70℃，提取时间32min条件下，黄酮提取率为5.88%。结论 采用低共熔溶剂作为提取剂提取枣渣黄酮，提取率明显优于传统乙醇提取法。本研究结果为枣类资源的充分开发利用提供一定理论支撑。     

苹果渣中总黄酮的超声波辅助提取及清除自由基活性研究

利用超声波辅助法提取苹果渣黄酮,对提取的苹果渣黄酮进行清除自由基活性试验.通过单因素试验,考察4个因素对黄酮提取率的影响.结果表明,苹果渣黄酮的最佳条件为:提取时间20min,超声波功率260W,提取温度55℃,料液比1 g:10 mL.在此条件下,通过实验验证得出,黄酮提取率平均值为2.5927%;当苹果渣黄酮浓度为0.085 1g/L时,苹果渣黄酮对DPPH自由基的清除率为52.50%.     

常用消毒灭菌法及其机理与应用

介绍了采用消毒灭菌方法,有加热消毒法,紫外线辐射法和化学药剂消毒法。常用化学药剂有醛类、含氯消毒剂、醇类消毒剂以及高锰酸钾、生石灰等,阐释了消毒与灭菌两个概念的区别。     

Probiotics and prebiotics--perspectives and challenges

Owing to their health benefits, probiotics and prebiotics are nowadays widely used in yogurts and fermented milks, which are leader products of functional foods worldwide. The world market for functional foods has grown rapidly in the last three decades, with an estimated size in 2003 of ca US$ 33 billion, while the European market estimation exceeded US$ 2 billion in the same year. However, the production of probiotics and prebiotics at industrial scale faces several challenges, including the search for economical and abundant raw materials for prebiotic production, the low-cost production of probiotics and the improvement of probiotic viability after storage or during the manufacturing process of the functional food. In this review, functional foods based on probiotics and prebiotics are introduced as a key biotechnological field with tremendous potential for innovation. A concise state of the art addressing the fundamentals and challenges for the development of new probiotic- and prebiotic-based foods is presented, the niches for future research being clearly identified and discussed.     

毛霉型低盐速成豆豉工业化生产工艺与设备

本文介绍了毛霉型低盐速成豆豉的工业化生产工艺及生产线的关键设备。     

益生素、益生菌与结肠癌

介绍了益生素和益生菌及其作用机理。在动物模型中，有大量的数据证实益生素和益生菌能够预防癌症．而在人体内还没有直接实验证据。它们抑制癌症的确切机理目前尚不清楚，其抑制机理可能是：肠道菌群代谢活动的改变，肠道理化环境的改变，潜在的致癌物质的黏附和降解，肠道菌群的改变、抗癌或抗诱变物质的形成、提高宿主的免疫应答、影响宿主的生理活动以及发酵不能被消化的食物并形成有益代谢产物。     

European citizen and consumer attitudes and preferences regarding beef and pork

This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries.     

节能节水型印染助剂和设备的现状

从节能、节水、缩短工艺流程和环保的角度出发，介绍了国内外研制开发的一系列新型节能、节水型印染助剂和染整设备。     

组学技术与果蔬采后质量和安全控制

果蔬可以提供营养, 有利于人类健康, 而果蔬的后熟及其与环境的相互作用会影响果蔬采后的质量和安全。对果蔬生物学过程的了解和掌握是减少果蔬采后损失和保障果蔬采后质量和安全的关键。在过去的10多年, 基于组学技术的系统生物学在了解果蔬后熟及其与环境相互作用的分子机制方面得到了越来越多的应用。本文对此做了细致的总结, 指出了存在的不足, 并提出了未来的发展方向。     

Heritability and correlations for body condition score and dairy form within and across lactation and age

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.     

原花色素及其开发应用

对原花色素的结构、化学特性、制备、分析方法、应用前景作一综述,并重点讨论其生理功能,为在功能性食品、药物、化妆品等领域的深入研究和开发提供参考。