排序方式： 共有51条查询结果，搜索用时 15 毫秒
1.
基于近红外光谱技术的茶油原产地快速鉴别 总被引：2，自引：3，他引：2
为研究茶油原产地溯源问题,维护其市场秩序,促进公平竞争。该文利用近红外光谱技术采集湖南、江西、安徽和浙江4个不同产地茶油的光谱数据,并运用 Savitzky-Golay 平滑（savitzky-golay, SG）、多元散射校正（multiplicative scatter correction, MSC）、一阶导数（first derivation, FD）和矢量归一化（vector normalization, VN）等4种方法对其进行预处理。采用偏最小二乘法（partial least squares, PLS）提取最佳主成分,构建 PLS 回归模型;同时,采用主成分分析（principal component analysis, PCA）和 PLS 算法提取最佳主成分,作为 BP 人工神经网络（BP artificial neural network, BPANN）输入变量,构建 PCA-BPANN 和 PLS-BPANN 模型。以验证集相关系数 RP 和验证集均方根误差 RMSEP 为模型的评价指标,分别优选最佳 PLS 和 BPANN 模型。试验结果表明,SG-PLS-DA 和 SG-PLS-BPANN-DA 模型对未知样本的整体分类准确率均大于90%。其中,SG-PLS-BPANN-DA 的鉴别效果优于前者,其建模集相关系数 RC、均方根误差 RMSEC 分别为0.974、0.170,验证集相关系数 RP、均方根误差 RMSEP 分别为0.972、0.172,对上述两类样本集的总体分类准确率分别为98.15%、95.83%,该模型能较准确鉴别茶油原产地。研究结果可为快速辨别茶油原产地提供参考。 相似文献
2.
玉米淀粉-辛烯基琥珀酸淀粉酯制备亚麻油微胶囊 总被引：5，自引：1，他引：4
为了降低生产成本,本文用价格低廉的天然蜡质玉米淀粉（NWMS）替代部分的辛烯基琥珀酸淀粉酯(OSAS)作为壁材,用高速剪切法处理乳液,经喷雾干燥后制备亚麻油微胶囊。将OSAS与NWMS按照5∶0、4∶1、3∶2和 2∶3（OSAS∶NWMS）的比例混合,试验结果表明,混合比例对于微胶囊颗粒的粒度没有显著影响;随着OSAS含量的增加,包埋率逐渐增大,当OSAS与NWMS混合比例为3∶2时,包埋率达到61.45%;随着NWMS含量的增加,微胶囊的含水率增大,表面变得更为光滑。NWMS可与OSAS混合作为亚麻油微胶囊的壁材,以达到降低成本的目的。 相似文献
3.
隐性乳房炎对牛乳蛋白质脂肪和乳糖含量的影响 总被引：1，自引：0，他引：1
对牛乳中主要营养物质含量进行了测定,并用 CMT 法检查了隐性乳房炎。结果表明,隐性乳房炎能显著地降低乳汁中蛋白质,脂肪和乳糖的含量,从而降低了牛乳的品质。 相似文献
4.
5.
日粮脂肪来源对肉鸡免疫功能的影响 总被引：7，自引：2，他引：5
肉鸡日粮中分别添加７％的猪油、玉米油、亚麻子油和鱼油,检测血清抗ＳＲＢＣ抗体滴度和伴刀豆球蛋白Ａ（ｃｏｎＡ）、商陆分裂素（ＰＷＭ）对脾脏淋巴细胞的增殖反应。结果表明,四种脂肪对抗体生成有明显促进作用,其中以鱼油作用更显著;四种脂肪亦可明显促进脾脏淋巴细胞增殖,但脂肪种类对促进淋巴细胞增殖作用差异不大;鱼油可促进肉鸡生长,其余三种脂肪对肉鸡体重影响不大。 相似文献
6.
加工工艺对油茶籽油氧化稳定性及酚类物质含量的影响 总被引：4，自引：1，他引：3
为了探究加工工艺对油茶籽油营养品质的影响,了解油酚类物质在加工工艺中的变化规律,该文从油茶籽油加工企业的生产线中取样,对压榨毛油和浸出毛油精炼工艺以及压榨毛油适度精炼工艺等不同工艺中油茶籽油中总酚、多酚组成及含量、抗氧化活性系数和油的氧化诱导时间等指标进行了测定。压榨毛油精炼工艺包括水洗、脱色、脱臭、冬化;浸出毛油精炼工艺包括碱炼、水洗、脱色、脱臭、冬化;压榨毛油适度精炼工艺包括脱胶、碱炼、水洗、冬化等工艺步骤。结果显示:压榨油茶籽毛油中总酚平均质量分数为103.06μg/g,显著高于浸出油茶籽油48.52μg/g(P0.05);油茶籽毛油经过精炼工艺后总酚和总酚的抗氧化活性均呈现下降趋势,三种精炼工艺后油茶籽油中总酚分别下降了88.9%,86.7%和63.81%,总酚的抗氧化活性分别下降了88.3%,93.51%和83.25%。适度精炼相比普通精炼对于保留油茶籽油中的多酚有明显优势,前者精炼后油茶籽油中总酚及其抗氧化活性系数分别为37.82μg/g和9.33%,后者仅为11.41μg/g和4.71%。通过高效液相色谱测定发现,浸出油茶籽毛油精炼后仅含有少量肉桂酸,压榨毛油传统精炼后压榨油茶籽油中测到苯甲酸、芦丁和肉桂酸等3种多酚的质量分数分别为4.7、1.58和0.22μg/g,压榨毛油适度精炼后的油茶籽油中测到了单宁酸、绿原酸、表儿茶素等9种多酚,其中单宁酸和绿原酸的质量分数最高,分别为4.57和3.26μg/g;适度精炼后油茶籽油氧化诱导时间从初始的8.56 h增加到11.66 h,增加了26.63%;压榨毛油传统精炼后油茶籽油氧化诱导时间从8.14 h增加到10.42 h,增加了21.83%。研究结果表明,压榨毛油适度精炼相比传统精炼工艺对于保留油茶籽油中多酚等成分有明显优势,所生产的茶油具有更强的氧化稳定性。研究结果为油茶籽油中营养成分的保留提供了途径,为油茶籽油加工工艺选择提供参考。 相似文献
7.
8.
M. H. Lyimo S. Nyagwegwe A. P. Mnkeni 《Plant foods for human nutrition (Dordrecht, Netherlands)》1991,41(1):53-57
The effect of traditional food proceesing, preservation and storage methods on vegetable nutrients was studied using cassava, pumpkin and mwage leaves. Traditional cooking method for 90 min for cassava, 50 min for pumpkin and mwage leaves resulted in significant losses in protein, fats and vitamins. Sundrying using traditional mats caused losses of vitamin A of 36.3%, 38.0% and 50.3% for cassava pumpkin and mwage leaves respectively. Storage using earthenware pots for six weeks resulted in significant losses of vitamin C. In general, traditional methods for processing, preservation and storage of vegetables cause significant losses of nutrients, an effect that could account for poor, nutritional status in Morogoro region (Tanzania). 相似文献
9.
紫苏子油纳米乳的制备及其对小鼠急性高血脂症的影响 总被引：1，自引：1，他引：0
通过绘制伪三元相图优选处方,采用滴定法制备紫苏子油纳米乳,用透射电子显微镜(TEM)、激光粒度测定仪分别考察其形态和粒径,通过恒温加速试验考察其稳定性,并研究其对急性小鼠高血脂症的影响。结果显示,以小麦胚芽油为油相,聚氧乙烯氢化蓖麻油(RH40)为表面活性剂制备的紫苏子油纳米乳外观澄明,有淡蓝色乳光;电镜下呈圆球形,平均粒径为58 nm,高速离心、高温下无絮凝或药物析出。与紫苏子油软胶囊对抗急性小鼠高血脂症的药效比较,紫苏子油纳米乳有更强的抗高血脂功效。结果表明,制备的紫苏子油纳米乳是一种质量稳定、高效的抗高血脂乳剂。 相似文献
10.
Effect of marine by‐product meals on hen egg production parameters,yolk lipid composition and sensory quality 
下载免费PDF全文
下载免费PDF全文 E. Toyes‐Vargas R. Ortega‐Pérez J. L. Espinoza‐Villavicencio M. Arellano‐Pérez R. Civera E. Palacios 《Journal of animal physiology and animal nutrition》2018,102(2):462-473
The effect of including 5% marine by‐product meals in feeds of laying hens on egg production, composition and sensory characteristics was tested. Marine by‐product meals were prepared using two methods: (i) cooking (100°C/10 min) followed by drying (60°C/24 hr) or (ii) grinding followed by drying. The raw materials used for meal production were scallop or squid viscera, shrimp heads or whole mackerel. A total of 108 laying hens were allocated to nine diet treatments; one control diet (corn and soya bean based) and eight experimental diets, containing 95% of the control feed and 5% of the experimental meal for three weeks. Daily intake was higher in hens fed the dried mackerel and cooked shrimp meals. All the experimental treatments showed significantly higher concentration of n‐3 HUFA in yolk reserves and phospholipids compared to the control (0.12–0.13 g per 100 g), especially those with scallop or squid prepared by both methods (0.53–0.95 g per 100 g). Scallop, squid and shrimp meal inclusion in the feed produced eggs with more astaxanthin (0.22 mg per 100 g) while this carotenoid was absent in the control and mackerel treatments. Visual evaluation of raw yolk colour increased with the inclusion of marine by‐product meals with higher values in hens fed shrimp heads (13), followed by scallop viscera (11), squid viscera (9), and with similar values for mackerel and control (4). The taste, aroma, texture and colour of cooked eggs from different treatments were not statically different when evaluated by a panel of 60 untrained people. These results suggest that meals from marine by‐products are a better alternative for improving egg yolk composition by increasing n‐3 HUFA when compared to fishmeal as they also increase astaxanthin and yolk pigmentation without affecting egg sensory characteristics. 相似文献