奶牛生产性能测定技术在太原市规模牧场的应用

为了解奶牛生产性能测定(dairy herd improvement,DHI)在太原市奶牛场的应用情况及其对产奶量的影响,本研究对2020年11月份太原市8个规模牧场的3188头DHI参测牛数据进行分析,结果发现泌乳牛的平均日单产为27.39kg、乳脂率为3.67％、乳蛋白率为3.59％、体细胞数为22.53万/mL、...     

灯光诱饵技术对深水网箱养殖鱼类品质的影响

为评估太阳能灯光诱饵技术在深水网箱养殖鱼类品质改善方面的应用效果,本研究在青岛金沙滩海域的深水网箱中设计并安装太阳能灯光诱饵设备,通过“灯光诱饵”吸引活体饵料聚集于网箱内,从而为实验大黄鱼(Pseudosciaena crocea)、鲈鱼(Lateolabrax japonicus)和真鲷(Pagrus major)提供天然饵料,全程无人工投饵,使其在自然状态下,拟半野生化养殖至上市。大黄鱼、鲈鱼和真鲷经过5个月的实验网箱及传统网箱养殖后,通过测定其脂肪、脂肪酸和氨基酸含量判断其品质。结果显示,在安装灯光诱饵设备的影响下,网箱养殖大黄鱼、鲈鱼和真鲷的感官性状显著好于传统网箱养殖鱼类,11月3种鱼体肥满度比6月均显著下降(P<0.05)。灯光诱饵网箱养殖大黄鱼和真鲷肌肉内粗脂肪含量分别比传统网箱养殖低75.24%和46.81%,差异极显著(P<0.01),鲈鱼差异不显著(P>0.05)。灯光诱饵网箱养殖大黄鱼、鲈鱼和真鲷肌肉内DHA含量高于传统网箱养殖鱼类,差异极显著(P<0.01);总脂肪酸含量、棕榈酸含量低于传统网箱养殖鱼类,差异极显著(P<0.01)。灯光诱饵网箱养殖的3种鱼的肌肉内的呈味氨基酸、呈鲜味氨基酸、呈甘味氨基酸、总氨基酸和非必需氨基酸含量均升高,其中大黄鱼变化最显著,实验组比对照组的呈味氨基酸、呈鲜味氨基酸和呈甘味氨基酸含量分别高11.78%、9.17%和19.57%,差异显著(P<0.05)。研究表明,太阳能灯光诱饵深水网箱养鱼技术虽然降低了养殖鱼类的生长速度,但可以改善养殖鱼类品质,且养殖投入明显降低,养殖收入显著提高,该方法可显著提升产出效益,因此,可作为一种绿色健康养殖模式进行推广应用。     

鲈鱼幼鱼人工配合饲料中蛋白质,脂肪适宜含量的研究

探讨了人工配合料中蛋白质,脂肪对鲈鱼幼鱼生长的影响,对各试验组幼鱼肝组织中的脂肪含量进行了比较,经３５ｄ试验养殖,结果表明：鲈鱼幼鱼配合饲料中蛋白质和脂肪的含量分别为３９．８５％～４０．１２％和５．４％～１５．４％时较为适宜。     

不同生态区、不同品种玉米脂肪和蛋白质含量研究

以奥玉3101、强盛49号、东单60号、屯玉42号和农大108等5个玉米品种作为试验对象,对玉米的脂肪和蛋白质含量进行了研究。试验分别在太谷县、榆社县、平遥县、太原市和长子县等4个不同生态区进行。试验结果表明:不同生态区对5个玉米品种的脂肪和蛋白质含量影响较大。不同生态区、品种间、生态区×品种间玉米脂肪含量均达1%极显著水平,不同生态区、生态区×品种间玉米蛋白质含量差异均达1%极显著水平。     

向日葵籽仁脂肪和脂肪酸含量近红外光谱模型的建立

为实现向日葵品质的快速无损检测,选取50份具有代表性的油用向日葵材料,采用偏最小二乘法（PLS）构建籽仁脂肪、亚油酸、油酸、硬脂酸和棕榈酸含量的近红外光谱（NIRS）模型。结果表明,脂肪、亚油酸、油酸含量模型校正和验证相关系数均大于0.96,且预测值与化学值相对误差均在10%以下,能够达到样品成分含量的快速测定。硬脂酸和棕榈酸含量模型校正相关系数分别为0.92和0.82,验证相关系数分别为0.83和0.74,预测值与化学值相对误差在4.66%~17.99%之间,可用于样品成分含量的初步预测。本研究构建的NIRS模型,有助于油用向日葵种质资源品质鉴定和快速筛选。     

帽儿山异色瓢虫野外越冬前体内甘油·脂肪含量的变化

[目的]明确野外越冬异色瓢虫[Harmonia axyridis(Pallas)]成虫体内甘油、脂肪2种物质越冬前的动态变化.[方法]利用动力学方法和重量法,分别测定了其体内甘油和脂肪含量.[结果]昼长及温、湿度共同影响异色瓢虫越冬前体内甘油和脂肪含量的变化;在异色瓢虫越冬前,虫体脂肪含量达到最低值,于部分异色瓢虫越冬期间达到最高值;而虫体甘油含量在异色瓢虫越冬前期及部分异色瓢虫越冬期间达到最高值,在几乎全部异色瓢虫越冬期间降到最低值;甘油、脂肪含量变化与昼长及温、湿度变化呈一定相关性,但不显著.[结论]异色瓢虫体内甘油与脂肪含量在越冬前呈互补变化,在部分及全部异色瓢虫越冬期间均呈现上升和下降相似变化,其相应生化指标可作为异色瓢虫越冬的指示.     

Effect of fat level,mixing pressure and temperature on dough expansion capacity during proving

In this work the effect of fat content on dough aeration during proving was investigated using dynamic dough density measurements. Doughs of three different fat levels (0%, 0.04% and 0.2% flour basis) were mixed under various pressures using a Tweedy mixer and proved at five different temperatures (30, 35, 40, 45 and 50 °C) in the dynamic dough density system. The dough expansion capacity and the time of the gas loss of each dough sample were measured and related to fat level, mixing pressure and proving temperature.     

Preparation and fermentation of rice-defatted soy flour blends: Effect on protein,fat and ash content

Rice-defatted soy flour blends prepared in three proportions viz. 40:60, 50:50 and 60:40 were fermented with buttermilk at 25, 30 and 35°C for 12, 18 and 24h. Fermentation of these blends lowered the pH and raised the titratable acidity, maximum drop in pH and rise in titratable acidity being observed at 35°C for 24h. The fermentation either decreased or did not change the protein content of cereal-legume blends. Fat as well as ash content remained unaltered irrespective of temperature and time period of fermentation.     

Oat β-glucan-amylodextrins: Preliminary preparations and biological properties

Amylodextrins with soluble -glucan contents from 1 to 10% were prepared from oats and the hypocholesterolemic properties of the latter were evaluated. The products are called OATRIM and can lower blood cholesterol by replacing animal fats rich in cholesterol in food products and, possibly, by the action of -glucan in the body after consumption. In the chick model, decreased total blood cholesterol also resulted in increases of HDL cholesterol and decreases of LDL cholesterol. Processing conditions were found that gave the maximum amount of -glucan and desirable fat-replacement qualities with the least amount of color and flavor.The mention of firm names or trade products does not imply that they are endorsed or recommended by the US Department of Agriculture over other firms or similar products not mentioned.     

均质对香蕉牛奶脂肪上浮的影响

由于香蕉浆改变了牛奶的稳定性，导致香蕉牛奶容易发生脂肪上浮。本文分析了不同均质压力与温度对香蕉牛奶脂肪上浮情况的影响，并确定了香蕉牛奶生产流程的均质条件。本试验采用的均质总压力为15MPa、16MPa和17MPa，二级压力为3MPa、3.5MPa、4MPa，均质温度为55℃、60℃、65℃、70℃、75℃、80℃、85℃，并对保质期内1个月、3个月、5个月的香蕉牛奶上层脂肪含量进行检测。结果表明均质温度设置为70℃，均质总压力设置为17MPa，二级压力设置为3.5MPa，脂肪上浮情况可以得到明显的抑制。