猪油溶剂法分提产物性质分析

选取精制猪油为原料,采用溶剂法分提改性,对精制猪油和分提产物进行了碘值、熔点测定以及脂肪酸组成、固体脂肪含量等性质的分析,对分提液脂中1,3-二油酸-2-棕榈酸甘油三酯(OPO)含量进行了测定。结果表明:分提液脂熔点降低,碘值升高,而分提固脂熔点升高,碘值降低;精制猪油和分提产物的脂肪酸种类一致,都以油酸、棕榈酸为主,分提液脂中的不饱和脂肪酸含量明显提高,饱和脂肪酸含量下降,分提固脂则与之相反;精制猪油、分提液脂和分提固脂的Sn-2位脂肪酸分布都以棕榈酸为主,分别占68.74%、63.70%、78.01%;分提液脂中OPO含量为30.43%,相比分提前精制猪油(OPO含量22.60%)有一定程度的富集;热力学性质分析结果与理化指标测定结果以及脂肪酸分析结果趋势一致。分析结果为分提固脂和分提液脂在食品工业中的应用提供了理论基础。     

猪油的干法分提工艺实践

结合工程实践,针对猪油固脂含量及脂肪酸组成特点,确定了猪油干法分提的分提初温、冷却水温与油温温差控制、搅拌速度、输送方式、过滤压力等工艺参数.实践表明:熔点为24℃的猪油经一次分提可得到熔点为15℃的液态猪油,得率为65％左右,压滤的固脂滤饼中液态猪油含量低.     

猪油OPO富集与猪油分提组分物性研究

本试验利用干法分提、溶剂法分提和干法偶联溶剂法分提3种工艺来对猪油进行改性,对比了3种不同工艺条件下的分提液脂的1,3-2油酸-2棕榈酸(OPO)富集效果,同时对每种工艺条件下的分提产物进行了全面的理化性质分析。试验结果表明:分提液脂中OPO含量均有一定程度的富集,干法分提液脂的OPO含量为26.12%,溶剂法分提液脂OPO含量为34.02%,干法偶联溶剂法分提工艺OPO含量为43.36%,确定富集OPO的最佳工艺条件为干法偶联溶剂法分提工艺。     

干法分提制备液化猪油工艺

为使猪油在常温下可呈液态,采用两次干法分提的方法对结晶温度、冷却速率、养晶时间分别进行单因素和正交试验：将猪油加热平衡后以一定的速率冷却至一定的温度,在晶核形成后经过特定的时间进行养晶使晶体形成,最后通过离心法使固液相分离;同时探讨搅拌方式和一次干法分提的平衡温度对分提效果的影响。结果表明：一次分提最佳条件为结晶温度21℃、冷却速率2℃/h、养晶时间14h;二次分提最佳条件为结晶温度16℃、冷却速率0.5℃/h、养晶时间30h;一次分提液化猪油的得率可达81.59%,二次分提液化猪油的得率可达79.93%。经二次干法分提得到的猪油在室温下可呈液态。     

β-环糊精脱除猪油中胆固醇的研究北大核心CSCD

为脱除猪油中胆固醇、提高猪油品质,研究以猪油为原料,选择β-环糊精包合法、硅胶吸附法和分子蒸馏法对猪油进行胆固醇脱除,分析了3种方法脱除胆固醇效果和对猪油酸值、过氧化值的影响。结果表明,β-环糊精包合法优于另外两种方法。然后对β-环糊精脱除猪油中胆固醇的工艺条件进行优化,以胆固醇脱除率为指标,考察β-环糊精添加量、水油比、搅拌时间对胆固醇脱除率的影响,通过单因素实验和响应面实验分析得到β-环糊精脱除猪油中胆固醇最佳工艺条件为β-环糊精添加量2.8%、水油比1.2∶1、搅拌时间41 min、搅拌温度50℃、搅拌速度1 000 r/min,在最佳工艺条件下胆固醇脱除率为67.54%。回收β-环糊精重复利用5次胆固醇脱除率为61.9%,仍具有很高的脱除效率。     

接枝β-环糊精米糠纤维脱除猪油中的胆固醇

采用接枝β-环糊精米糠纤维脱除猪油中的胆固醇,根据单因素试验结果,初步得到了脱除猪油中胆固醇的最佳工艺条件为：反应时间120min,加水量40％（猪油质量）,反应温度50℃,接枝β-环糊精米糠纤维的添加量8％。在该条件下,猪油中胆固醇的含量可从539．8mg／kg降低到72．1mg／kg,脱除率达到86．6％。比较了接枝β-环糊精米糠纤维、普通米糠纤维、β-环糊精对猪油中胆固醇的脱除效果。发现在一定反应条件下,接枝β-环糊精米糠纤维的脱除效果最佳。回收后的接枝β-环糊精米糠纤维在重复使用5次后,对胆固醇的脱除率仅降低了13．4％。     

表面活性剂分提猪油的工艺研究

采用表面活性剂对原料猪油进行二次分提,得到4种形态的猪油;通过正交实验系统考察了二次分提猪油过程中表面活性剂浓度、电解质浓度、养晶温度、养晶时间等对猪油得率的影响,得出一次和二次分提猪油的最佳工艺条件,最后测定了产品猪油的理化指标.     

β-环糊精脱除猪油中胆固醇的研究

为脱除猪油中胆固醇、提高猪油品质,研究以猪油为原料,选择β-环糊精包合法、硅胶吸附法和分子蒸馏法对猪油进行胆固醇脱除,分析了3种方法脱除胆固醇效果和对猪油酸值、过氧化值的影响。结果表明,β-环糊精包合法优于另外两种方法。然后对β-环糊精脱除猪油中胆固醇的工艺条件进行优化,以胆固醇脱除率为指标,考察β-环糊精添加量、水油比、搅拌时间对胆固醇脱除率的影响,通过单因素实验和响应面实验分析得到β-环糊精脱除猪油中胆固醇最佳工艺条件为β-环糊精添加量2.8%、水油比1.2∶1、搅拌时间41 min、搅拌温度50℃、搅拌速度1 000 r/min,在最佳工艺条件下胆固醇脱除率为67.54%。回收β-环糊精重复利用5次胆固醇脱除率为61.9%,仍具有很高的脱除效率。     

巴沙硬脂与6种油脂相容性的研究

利用固体脂肪含量等温曲线(SFC-T)和固体脂肪含量偏差曲线(ΔSFC-T),研究了几种常见的起酥油及人造奶油基料油——巴沙鱼油(BO)、棕榈仁油(PKO)、棕榈油中间分提物(PMF)、猪油(LO)、牛油及棕榈硬脂(PS)与巴沙硬脂之间的二元相容性。结果表明:熔点为53.1℃的棕榈硬脂及熔点为46.8℃的牛油与巴沙硬脂的相容性最好;其他油脂与巴沙硬脂混合时相容性较好的含量范围为棕榈仁油含量10%,棕榈油中间分提物含量10%~40%,猪油含量10%~20%及50%,巴沙鱼油含量10%~20%及50%。     

影响猪油干法分提因素探讨

猪油是不同甘油三酯组成混合物,其中S3含量为5％,S2U含量为32％~39％,SU2含量为 46％~60％,U3含量为3％~10％,可通过干法分提把熔点相差较大甘油三酯分离。影响猪油干法分提 参数有:结晶温度、冷却速率、养晶时间、搅拌速率及分离方式。干法分提结晶温度为20~26℃(由冷却 曲线决定),冷却速率为2~6℃／h,养晶时间为6~12 h,搅拌速率为0~50 rmp,可采用离心或过滤(真 空或压力过滤)等分离方式,这些条件决定分提效果。     

植物甾醇来源、提取、分析技术及其食品开发

植物甾醇是一种类似于环状醇结构物质,主要存在于植物油不皂化物中,是一种多功能因子,具有降胆固醇等生理功能;目前植物甾醇及其衍生物广泛应用于医药、食品及化妆品等行业。该文对植物甾醇的来源、生理功能、提取、分析、安全性及产品开发等方面研究近况作一概述。     

家庭烹调对鲟鱼中脂肪酸和胆固醇的影响

对杂交鲟鱼（Acipenser baerii×A. schrenckii）进行了清蒸、油煎、微波、微波烤、烤箱烤和压力锅煎6 种家庭烹调处理,测定其脂肪和胆固醇含量、脂肪氧化指标和各脂肪酸含量的变化。结果表明,所有烹调方法均降低了n-3/n-6多不饱和脂肪酸含量的比值,其中压力烹调比值最高（0.85）,清蒸次之（0.83）,而烤箱烤最低（0.73）。胆固醇保存率以清蒸和压力锅煎最高,两种处理间无显著差异。烹调后样品酸价和硫代巴比妥酸值上升而过氧化值下降,并与样品的胆固醇含量相关。清蒸和压力烹调中脂肪酸和胆固醇变化相对较少,可能与其密闭烹调条件造成氧化程度较低有关。     

慕萨莱思葡萄酒对高脂血症SD大鼠血脂的影响

为探讨慕萨莱思葡萄酒对高脂饮食诱导的高脂血症SD大鼠血脂调节的影响,选用SD大鼠,通过高脂饲料饲喂建立高脂模型,分别灌胃慕萨莱思（3 mL/kg、6 mL/kg、9 mL/kg）、脱酒精慕萨莱思（9 mL/kg）、生理盐水（9 mL/kg）、酒精（11%vol）,全部SD大鼠连续灌胃给药4周后检测血清中总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）和高密度脂蛋白胆固醇（HDL-C）含量,并计算致动脉硬化指数（AI）和肝脏指数。结果显示,慕萨莱思高中低剂量组和慕萨莱思脱酒精组能显著降低高脂血SD大鼠血清内TC、TG、LDL-C含量、显著降低AI和肝脏指数（P＜0.05）。慕萨莱思脱酒精组、慕萨莱思中剂量组效果较好（TC（1.58 mmol/L/1.6 mmol/L）、TG（0.77 mmol/L/1.05 mmol/L）、LDL-C（0.49 mmol/L/0.65 mmol/L））,酒精组（11%vol）无明显效果。     

Cholesterol Oxidation in Fish and Fish Products

Fish and fish products are important from a nutritional point of view due to the presence of high biological value proteins and the high content of polyunsaturated fatty acids, especially those of the n‐3 series, and above all eicosapentaenoic acid and docosahexaenoic acid. However, these important food products also contain significant amounts of cholesterol. Although cholesterol participates in essential functions in the human body, it is unstable, especially in the presence of light, oxygen, radiation, and high temperatures that can cause the formation of cholesterol oxidation products or cholesterol oxides, which are prejudicial to human health. Fish processing involves high and low temperatures, as well as other methods for microbiological control, which increases shelf life and consequently added value; however, such processes favor the formation of cholesterol oxidation products. This review brings together data on the formation of cholesterol oxides during the preparation and processing of fish into food products which are recognized and recommended for their nutritional properties.     

Chemical Composition and Cholesterol Content in M. Longissimus Dorsi from Free-range Reared Swallow-belly Mangalitsa: The Effect of Gender

The objective of this study was to determine chemical composition and cholesterol content in M. longissimus dorsi (MLD) of Swallow-belly Mangalitsa, free-range reared, and to investigate possible effects of gender on these quality parameters of its meat. Average moisture and fat contents were significantly different in male and female pig muscles. The differences in average values of ash, protein and cholesterol contents between the two groups (genders) of meat samples were not significant. In MLD samples of female pigs, total fat had a significant influence on cholesterol content, while this influence was not established in MLD of male pigs.     

常用染料助剂的检测与分析

结合实践经验,阐述了常用染料和助剂的检测步骤及要点;介绍了活性、分散染料的染色检验方法和助剂的固体质量分数、离子性、硅乳的含油量、含氢量和稳定性的检测方法.     

Heat-moisture treatment of high-amylose corn starch increases dietary fiber content and lowers plasma cholesterol in ovariectomized rats

ABSTRACT:  The effect of dietary high-amylose corn starch (HACS) of varying dietary fiber (DF) content on plasma cholesterol was examined in ovariectomized (OVX) rats. Gelatinized normal corn starch (G-CS) was used as a reference. OVX rats were fed a fiber-free purified diet containing G-CS, HACS, gelatinized high-amylose corn starch (G-HACS), or heat-moisture treated HACS (HM-HACS) at 400 g starch/kg diet for 21 d. The DF content of G-CS, HACS, G-HACS, and HM-HACS measured by the AOAC method was 0.1, 19.3, 2.4, and 64.5 g/100 g, respectively. The dry weight of cecal contents, cecal wall weight, the amount of short chain fatty acids in cecal contents, the amount of bile acids in small intestinal contents, and fecal excretion of neutral sterols increased logarithmically with increasing DF, while total plasma cholesterol concentration decreased. On the other hand, hepatic CYP7A1 activity, fecal dry weight, and fecal excretion of bile acids increased linearly with increasing DF, while body weight gain decreased. The hypocholesterolemic effect of HACS in OVX-rats appeared to be more effective by heat-moisture treatment.     

Cholesterol Oxidation in Egg Yolk Powder During Storage and Heating as Affected by Dietary Oils and Tocopherol

The effects of feeding flax, sunflower, palm and fish oils, with and without tocopherols, to laying hens was investigated on oxidative stability of cholesterol in egg yolk powders. Storage of spray-dried egg yolk powders at room temperature resulted in loss (p <0.05) of tocopherols. The initial levels of spray-dried yolk cholesterol oxides were 7–10 ppm and increased (p <0.05) with storage. The cholesterol oxide contents in the egg yolk powders were: fish > flax > sunflower > palm. Heating egg yolk powder increased (p <0.05) the amounts of total cholesterol oxides. Diets with tocopherol supplementation resulted in a decrease (p <0.05) of cholesterol oxides during storage and heating.     

Effect of slaughter season and muscle type on the fatty acid composition, including conjugated linoleic acid isomers, and nutritional value of intramuscular fat in organic beef

BACKGROUND: Consumer awareness regarding the intake of beef of organic origin is strongly associated with the beneficial outcomes to human health, the environment and animal welfare. In this paper the effects of slaughter season and muscle type on the fatty acid composition, conjugated linoleic acid (CLA) isomeric profile, total cholesterol, α‐tocopherol and β‐carotene contents and nutritional quality of intramuscular fat in organic beef (n = 30) are reported for the first time. RESULTS: Organic beef showed a very low total lipid content, with seasonal changes in the levels of some fatty acids, CLA isomers, n‐6/n‐3 polyunsaturated fatty acid (PUFA) ratio, total cholesterol and β‐carotene. In addition, differences between longissimus lumborum (relatively red) and semitendinosus (relatively white) muscles were found for many fatty acids, specific CLA contents, many CLA isomers and both PUFA/saturated fatty acid (SFA) and n‐6/n‐3 ratios. However, in spite of the seasonal and carcass variations, all organic meats analysed had values of beef similar to pasture‐fed cattle. CONCLUSION: From a nutritional perspective, organic meat from both slaughter seasons seems to have high CLA contents, PUFA/SFA and n‐6/n‐3 indices within the recommended values for the human diet. The data indicate that intramuscular fat in organic meat has a high nutritional value throughout the year. Copyright © 2012 Society of Chemical Industry     

多孔淀粉对卵巢切除大鼠脂质代谢的影响

目的:研究多孔淀粉对卵巢切除大鼠脂质代谢的影响。方法:将24只雌性SD大鼠按体质量随机分为3组,其中一组进行伪切除手术,其余两组进行双侧卵巢切除手术,手术后恢复1周,分别饲喂相应饲料。4周后,检测大鼠血脂、肝脂、粪便中中性固醇含量和胆汁酸含量以及肠道中典型微生物数量、短链脂肪酸浓度等指标。结果:多孔淀粉的替代添加可以显著降低大鼠血浆中甘油三酯(triglyceride,TG)、TG与高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)的比值(TG/HDL-C)、肝脏中总胆固醇(total cholesterol,TC)、TG和脂肪总质量,显著减少腹部脂肪堆积(P0.05);显著增加粪便中中性固醇和胆汁酸的排泄量(P0.05);同时促进肠道中益生菌增殖和短链脂肪酸浓度的提高。结论:多孔淀粉对雌激素缺乏引起的高脂血症具有较好的降脂、降胆固醇效果,对内源性脂质代谢紊乱具有较好的缓解作用。