4种植物油热氧化同步荧光光谱分析     

李泳霖  谷宇欣  宫婷  王子健  潘政道  于修烛 《农产品加工．学刊》2020,(3):50-54,59

以亚麻籽油、大豆油、菜籽油与葵花籽油为原料,在不同温度条件下氧化并测定其不同时间的同步荧光光谱,分析同步荧光光谱及荧光物质变化情况。结果表明,4种植物油不同温度下的同步荧光光谱峰变化主要集中在300~415 nm内,且随着加热时间的延长存在波动现象;在50℃和150℃加热氧化条件下,300,330,375,415 nm这4个峰都存在明显的波动现象;二维相关分析表明,这4个峰的荧光强度变化速率不同,不同油变化差异较大;同种油在不同温度下,4个峰的波动情况、相互关系、变化速率均有明显差异。这些峰的变化与油脂氧化过程中荧光物质和油脂氧化程度的变化有关,可以利用同步荧光光谱的变化特性作为监控油脂氧化的依据。  相似文献   

香精油抗蜂螨作用的研究进展   总被引：2，自引：0，他引：2  

胡福良朱威  李英华 《养蜂科技》2004,(5):21-23,25

香精油及其组分具有显著的抗螨效果。萜类化合物(主要是单萜)是香精油的主要成分。占总量的90％左右。研究者通过筛选试验测定了多种香精油及其一些组分的抗螨能力。大部分表现出良好的抗螨效果。但只有少部分在蜂群试验中表现出强抗螨能力。因此，有必要对此作进一步的研究。以达到最优化目标。同时联合其它防治手段，建立一套全面的害虫防治策略，实现蜂螨的最终控制。  相似文献   

Efficacy of essential oils combination on performance,ileal bacterial counts,intestinal histology and immunocompetence of laying hens fed alternative lipid sources          下载免费PDF全文

Asma Mousavi  Amir Hossein Mahdavi  Ahmad Riasi  Masoud Soltani‐Ghombavani 《Journal of animal physiology and animal nutrition》2018,102(5):1245-1256

This study was carried out to assess the effects of a blend of herbal essential oils (namely Thymus vulgaris, Mentha piperita, Rosmarinus offisinalis and Anethum graveolens) and different dietary lipid sources on the performance, ileal bacterial enumeration, intestinal histological alterations and immune responses in laying hens. For this purpose, a total of 150 laying hens were randomly allocated to six experimental treatments with five replicates of five birds each. Dietary treatments consisted of three levels of a mixture of essential oils (0, 100 and 200 mg/kg) and two sources of lipid (soybean oil and fish oil containing different ratios of n‐6 to n‐3 fatty acids) fed to the animals during an 80‐days feeding trial. Findings indicated that dietary administration of fish oil not only increased significantly the spleen relative weight (p < 0.01) and the antibody titre against Newcastle virus (p < 0.05) but also led to reductions in liver relative weight (p < 0.05) and feed conversion ratio (p < 0.05). Moreover, the mixture of herbal essential oils brought about declines in hepatic relative weight, heterophile to lymphocyte ratio (p < 0.05) and intestinal pathogen populations (p < 0.01). Mention must also be made of the improvements it made in spleen weight (p < 0.01), antibody titres against SRBC (p < 0.01) and Newcastle virus (p < 0.05), villus height to crypt depth ratio (p < 0.01), goblet cell numbers (p < 0.05), lamina propria lymphatic follicle diameters (p < 0.01) and feed conversion ratio (p = 0.06). It may be claimed that the enhancements observed in the performance of laying hens fed fish oil and 200 mg/kg of the blend of essential oils could have potentially been associated with improved intestinal health indices as well as cellular and humoral immune responses.  相似文献   

Effects of oral administration of different dosages of carvacrol essential oils on intestinal barrier function in broilers          下载免费PDF全文

ShuDong Liu  MinHo Song  Won Yun  JiHwan Lee  ChangHee Lee  WooGi Kwak  NamSoo Han  HyeunBum Kim  JinHo Cho 《Journal of animal physiology and animal nutrition》2018,102(5):1257-1265

Essential oils are widely used in the pharmaceutical, food and cosmetic industries, and many plant essential oils have shown that they have positive effects on broilers nutrition. This experiment was conducted to study the effects of orally administered different dosages of carvacrol essential oils on intestinal barrier function in broiler chickens. A total of eighty 28‐day‐old (1.28 ± 0.15 kg) ROSS 308 broilers were randomly allocated to four groups of 20 replicates each, with one chicken per replicate per cage, and all were fed with the same diet. Four experimental groups were orally administered 0, 200, 300 or 400 μl carvacrol essential oils at 18:00 hr every day during the 2‐week experimental period. As a result of which, the gene expression of the occludin, claudin‐1, claudin‐5, ZO‐1 and ZO‐2 in intestinal mucosa of small intestine (p < 0.05) and the goblet cell content in small intestine epithelium (p < 0.05) were significantly increased; test subjects with 300 or 400 μl carvacrol essential oils reduced the microbial counts of Salmonella spp. and Escherichia coli in the intestines (p < 0.05); Essential oils administration also significantly increased activity of the sucrase (p < 0.05) and lactase (p < 0.05) in intestinal mucosa. In conclusion, the carvacrol essential oils have positive effects on growth performance and intestinal barriers function of broilers; those effects may be related to the dosage, as administration of 300 or 400 μl was more effective than that of 200 μl.  相似文献   

果蔬籽油生物活性研究进展     

贺明  解志轲  于书燕  肖海芳 《中国果菜》2020,(1):6-10

果蔬籽油是由果蔬籽经压榨或萃取工艺制得的植物油脂。果蔬籽油含有丰富的维生素、多不饱和脂肪酸、有机酸等活性成分,这些成分赋予了果蔬籽油抗氧化、抗癌、调节血脂和调节免疫系统等生物活性。本文综述了果蔬籽油生物活性的研究进展,旨在为果蔬籽油的综合开发和利用提供理论依据和指导。  相似文献   

Analgesic effect of the mint terpenoid L-carvone in sheep     

《Veterinary anaesthesia and analgesia》2023,50(5):459-465

ObjectiveTo determine whether L-carvone increases the voltage threshold response to a noxious electrical stimulus in sheep.Study designProspective, blinded, randomized, crossover experimental study.AnimalsA group of six healthy adult sheep.MethodsSheep were instrumented with cranial dorsothoracic subcutaneous copper electrodes. A stimulator delivered a 10 ms square-wave stimulus at 50 pps starting at 0.1 V with a 0.2 V second^–1 ramp. The stimulus stopped once two observers who were blinded to treatment noted a behavioral pain response or when a 15 V cut-off was reached. Next, 0.15 mL kg^–1 of either a 50% L-carvone solution or a saline-vehicle control was administered intramuscularly, and electrical threshold responses were measured every 5–15 minutes over a 6 hour period using methods identical to the baseline. One week following the first treatment (L-carvone or control), sheep were studied using identical methods with the second treatment (control or L-carvone). Drug and time effects were evaluated using a two-way repeated measures analysis of variance, and pairwise comparisons were evaluated with Holm-Sidák tests with values of p < 0.05 considered significant.ResultsL-carvone significantly increased voltage threshold responses for most time points up to 75 minutes compared with baseline and with saline control. The last time point with a significantly different response between L-carvone and saline treatments was 5 hours after drug administration. The saline-vehicle control decreased voltage threshold responses at several time points after 3 hours.Conclusions and clinical relevanceIntramuscular L-carvone is analgesic in sheep, although the ethanol-propylene glycol vehicle may cause mild hyperalgesia. This study demonstrates that a food-derived compound can be used to relieve pain in a food-producing animal.  相似文献   

柴油机燃用复合乳化燃料放热率的计算模型     

王宇  刘远军  姚喜贵  张启安 《农业机械学报》2001,32(1):23-26

提出了适用于柴油、甲醇、水三元复合乳化燃料和柴油的热力学放热率计算模型，并利用此模型对直接喷射式2135G型柴油机进行了放热率计算研究，计算结果令人满意。同时分析研究了压力传感通道效率、计算步长；乳化燃料中水的化潜热及示功图光顺程度等因素对复合乳化燃料放热率计算精度的影响。  相似文献   

基于改进UNet模型的油茶果振动采摘点定位方法     

王金鹏  何萌  甄乾广  胡皓若  袁飞  陈苏楠  方宸哲  周宏平 《农业工程学报》2024,40(8):171-178

针对非花果同期油茶果采收效率低这一问题,提出一种侧枝振动采摘点定位方法,通过振动侧枝降低树木损伤并实现高效采收。首先构建数据集,对侧枝分段标注,向UNet中添加CloFormer注意力机制并命名为Clo-UNet,实现侧枝的二维重构。其次,在Clo-UNet基础上进一步设计采摘点定位方法并命名为Clo-UNet-Point,该方法优先选择采收离果实最远且最粗的枝条。试验表明,Clo-UNet在验证集上表现优异,其中br_con（连果枝）、danger（危险区）和br_pro（优先采收区域）的平均交并比mIoU分别达到85.36%、86.37%和81.29%,平均像素精度mPA分别达到94.97%、96.17%和89.48%,Clo-UNet在整个数据集上的mIoU和mPA分别比UNet高5.14、6.85个百分点。通过观察验证集647幅图像,Clo-UNet-Point算法在不同光照条件下均能定位到采摘点,平均检测一张图像用时0.15 s。该研究可为未来非花果同期类油茶果的自动化振动采收奠定理论基础。  相似文献   

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  

文韬  郑立章  龚中良  李立君  谢洁飞  马强 《农业工程学报》2016,32(16):293-299

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   

食用油反式脂肪酸傅里叶红外光谱重组检测技术   总被引：5，自引：2，他引：3  

于修烛  杜双奎  岳田利  王青林 《农业机械学报》2009,40(1):114-119

以食用油、反式脂肪酸标样及矿物精油为试验材料,采用傅里叶红外光谱重组(SR-FTIR)技术检测食用油中反式脂肪酸含量,并与标准红外分析方法(SB-ATR-FTIR法)进行比较.结果表明:SR-FTIR模型反式脂肪酸含量预测值与实际加入量高度线性相关,斜率为1.02,标准差小于0.05;SR-FTIR模型的灵敏度要比标准方法模型高20余倍.  相似文献