Research progress on classification,source,application of phytosterol esters,and their thermal oxidation stability

Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailability than free phytosterols.In recent years,phytosterol esters have attracted increasing attention.However,during food processing,phytosterol esters are susceptible to degradation at high temperatures,resulting in certain losses and formation of potentially harmful substances for humans.This paper reviews the relevant literatures and updates on the thermal oxidation stability of phytosterol esters in recent years from the following aspects:(i)Sources,physiological activities,and applications of phytosterol esters;(ii)Oxidation mechanism of phytosterol esters;(iii)Effects of phytosterols species,the volume of addition,food matrix,heating temperature and time,and antioxidants on the thermal loss and oxidation stability of phytosterol esters.The research progress on the safety of phytosterol esters is also discussed in detail.Additionally,the prospects for future research are highlighted.

Contents of Phytosterols in Vegetables and Fruits Commonly Consumed in China

Objective To quantify five specific dietary phytosterols and phytostanols in vegetables and fruits commonly consumed in China. Methods A total of 34 different kinds of vegetables and 33 kinds of fruits were chosen according to the consuming habit of Chinese people. All the samples were purchased from two shops in Beijing. The contents of phytosterols （13-sitosterol, campesterol, stigmasterol, 13-sitostanol, and campestanol） were analyzed by GLC method which was established by our laboratory, and the total phytosterols were calculated. Results The total phytosterol content in vegetables ranged 1.1-53.7 mg/100 g edible portion. The highest concentration was found in pea, cauliflower, broccoli, and romaine lettuce. The phytosterol contents in fruits ranged 1.6-32.6 mg/100 g, the highest concentration was found in navel orange, tangerine, and mango. Conclusion The phytosterol contents in vegetables and fruits are not as high as those in edible oils, but because of the large amount of consumption, they also play an important role in increasing the people＇s phytosterols intake, indicating that increased intake of vegetables and fruits with higher phytosterol contents helps increase the phytosterol intake in China.

Physiological Function of Phytosterol and Its Application

As a bioactive substance, phytosterol reduces blood cholesterol and the risk of cardiovascular disease. It also has such physiological functions as growth regulation, promotion of protein synthesis, anti-inflammatory, antioxidant, anticancer, immune regulation and hormone-like effects. Phytosterol does not show any toxicity to human and animals, and it is a new functional feed additive approved by the Ministry of Agriculture of China. This article generally reviewed the physiological function of phytosterol like regulation of cholesterol metabolism, antioxidation, hormone-like effects, and its application on animal, production like hypolipidemic and improving dairy animals＇ milk composition. The paper provides a reference for wide application of phytosterol in animal feed.

一株高效转化Phytosterol为雄甾烯酮菌株的筛选与鉴定

从保藏的200多株菌中筛选出1株高效转化植物甾醇为4-烯-雄甾-3,17-二酮和1,4-二烯-雄甾-3,17-二酮的菌株,并对该菌进行了形态、生理生化的研究。结果发现菌株ST06可以利用多种碳源,可以水解淀粉,但不利用纤微素。用16SrDNA的方法对其进行鉴定,发现与Bacillus属Bacillus amyloiquefaciens的相似性最高,达到99.9%,将该菌株命名为Bacillus amyloiquefaciens ST06。该菌在培养温度30℃,pH7.0,转速220r/min,转化时间7d,底物添加量为0.3%时,ADD与AD的总得率高达40%以上,此时底物转化率高达93.7%。

Phytosterol of Potamogeton maackianus and Its Change under the Stress of Microcystis aeruginosa

The phytosterol in Potamogeton maackianus was identified and quantified. From the hexane extracts analysis of unsaponifiable fraction ofP. maackianus by gas chromatography - mass spectrometry（GC-MS）, campesterol, stigmasterol and β-sitosterol were the main phytosterols in P. maackianus with the contents of 0.368, 1.17 and 0.824 mg·g^1, respectively. After 7 days＇ exposure under M. aeruginosa, the contents of campesterol, stigmasterol and β-sitosterol in P.maackianus increased by 23.1%, 40.4% and 40.8%, respectively. Both the contents of 24-ethyl sterols （sitosterol and stigmasterol） and 24-methyl sterol （campesterol） in macrophytes increased, but the percentage of total sterol composition did not change significantly. This result indicated that the content of 4-demethyl sterols and the second alkylation of the phytosterol side-chain at C-24 in P. maackianus were affected by M, aeruginosa.

Phytosterols in edible oil:Distribution,analysis and variation during processing

Phytosterols,which are naturally occurring in plants,have excellent nutritional and health values on lowering both the blood cholesterol level and the risk of cardiovascular diseases.Edible oils are the main source of daily intake of phytosterols,whereas the properties of phytosterols may vary a lot depending on their sources.During the processing of edible oil including refining and frying,phytosterol's content fluctuates,which influences the properties of the final product.Phytosterols and their derivatives undergo physical migration between different phases and chemical conversion during the processing,which reduces the quality and the commercial value of edible oils.Therein,the loss of phytosterols is the major concern in the process of neutralization and deodorization.In addition,oxidation and thermal degradation of phytosterols occur simultaneously during frying,which also reduces the content of phytosterols.Nevertheless,the oil matrix has a promoting or an inhibitory effect on the thermal oxidation of phytosterols.Therefore,various efforts have been devoted to analyzing and improving the remaining contents of phytosterols in edible oil.Regardless of the processing method,temperature plays an important role in the loss of phytosterols.At present,themain analysismethods of phytosterols include gas chromatography and liquid chromatography,inwhich the pretreatment of different types of phytosterols is also a crucial step.This review focused on the following topics comprehensively:(i)the distribution of phytosterols in the oil-containing plants and edible oils during the refining processing;(ii)the pretreatment and analysis methods of various phytosterols(free phytosterols,phytosteryl fatty acid esters,phytosteryl glycosides and acylated phytosteryl glycosides);(iii)the variation of phytosterols in process of esterification and oxidation,storage and so on.The study also proposed that the investigation in the loss and safety of phytosterols during processing of the vegetable oils should be proceeded further in combination with efficient and accurate chromatography methods.

Hydrophilic phytosterol derivatives: A short review on structural modifications, cholesterol-lowering activity and safety

Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the application of free phytosterols in the food industry. Chemical or enzymatic modifications were effective to improve the physicochemical properties as well as the bioavailability and cholesterollowering activity of phytosterols. Higher oil solubility and lower melting point of phytosterols have been achieved by esterification and transesterification with fatty acids and triacylglycerols so as to enhance the bioavailability, reduce formation of precipitates, and improve the sensory quality of products.While the researches on the improvement on its water solubility is a hot topic. Hydrophilic phytosterol derivatives have promising applications in the food industry because most of foods belong to aqueous matrix. Hydrophilic modification is useful and meaningful for phytosterols in both industrial and commercial applications. This review mainly highlights the hydrophilic phytosterol derivatives in the following aspects:(i) hydrophilic modifications of phytosterols by coupling with various polar components;(ii) cholesterol-lowering activity and possible molecular mechanisms of hydrophilic phytosterol derivatives on reducing serum cholesterol level;and(iii) safety evaluation of hydrophilic phytosterol derivatives in cell-culture studies, animal models and clinical trials.

GC-MS Analysis on Form and Content of Phytosterol in the Beans from Different Producing Areas

This paper established the GC-MS method to analyze phytosterol in beans and study the content and distribution of phytosterol in green beans,red beans,black beans and soybeans in 5 main producing areas of China(Inner Mongolia,Heilongjiang,Jilin,Hebei,Shandong).This paper used GC-MS method to analyze the content and distribution of campesterol,stigmasterol,sitostanol,brassicasterol,ergosterol,cycloartanol,cycloartenol,2,4-methylenecycloartanol,spinasterol,cholesterol and cholestanol in the beans from different producing areas.Results showed that the content of sterol in green beans was higher than in three other kinds of beans,and the content of sterol in red beans was the lowest.Different producing areas had a significant impact on the content of sterol in beans,and the dominant producing areas included Inner Mongolia and Heilongjiang.The study provided a basis for quality assessment and nutritional evaluation of beans and provided a reference for traceability and variety distinction study of other edible beans.

REFINING OF SULFATE SOAP AND EXTRACTING OF PHYTOSTEROLS

The sulfatc soap is refined through extracting unsaponifiable neutral substance using ethyl acetate and hcxane-acetone. The content of neutral substance in tall oil decreases from 32.8% to 17.4% and 18%. The acid number of tall oil increases from 119 to 169 and 153. The quality of tall oil is greatly improved. This provides a favorable condition for distillation of tall oil. The unsaponifiable neutral substance from crude sulfate soap mainly consists of tcrpene aldehydes, tcrpcnc alcohols, fatty alcohols and stcrols in which larixol is 26.3% and 18. 5%, stcrols arc 17% and 27.1% separately. The white crystals containing stcrols of 96.9% are obtained by crystallization and rccrystallization. The stcrols arc mainly β-sitostcrol and campcsterol.

Physiological Functions of Phytosterols and Their Application in Food

Phytosterols are a kind of active ingredients in plants with various physiological functions.Phytosterols have a good effect in antagonizing cholesterol and preventing cardiovascular diseases.They also have physiological functions including regulating growth,promoting protein synthesis,resisting inflammation,oxidation and cancer,and regulating immune and parahormones.In this paper,the physicochemical properties of phytosterols,the mechanism of lowering cholesterol,their application in food field and their development prospects were systematically reviewed.

Determination of phytosterols in <i>Oryza sativa</i>L. cultivars by liquid chromatography atmospheric chemical ionization time-of-flight mass spectrometer (LC-APCI-TOF-MS) coupled with a modified QuEChERS method

Development of analytical methods for the determination of phytosterols in whole grains is one of growing interests due to their clinical and nutritional functions in human. In this study, we examined simultaneous determination of β-si tosterol, stigmasterol and campesterol in Korean rice cultivars by liquid chromatography atmospheric chemical ionization time-of-flight mass spectrometer (LC-APCI-TOF-MS). The hulled rice samples were extracted using a modified QuEChERS and analyzed by LC-APCI -TOF-MS. The method was validated by low limit of detection (LOD) and limit of quantification (LOQ) values and high recovery values with low relative standard deviation (RSD). The highest concentration of sitosterol was detected in Hwasung and Undu rice cultivars, exhibiting approximately 195.5 and 191.7 mg/Kg, respectively. Stigmasterol and campesterol were detected at the highest level in Hwasung rice cultivar, giving the concentrations of approximately 70.0 and 53.9 mg/Kg, respectively. Sitosterol was determined to be a main phytosterol detected in the rice samples. Our data demonstrated that LC/APCI-TOF- MS coupled with QuEChERS method can be used as a simple tool for the determination of phytosterols in rice samples.

Biosynthesis of Succulent Bamboo Shoots of Bambusa balcooa into Phytosterols and Its Biotransformation into ADD

Fermentation of the succulent bamboo shoots of Bambusa balcooa Roxb. resulted in an enrichment of phytosterols from 0.12% to 0.62% dry weight as compared to that of the fresh unfermented samples. The bacterial strains responsible for higher accumulation of phytosterols during fermentation of the bamboo shoots have been isolated and further extraction and purification of the crude phytosterols (isolated from the fermented samples) were done by TLC, UV, NMR, IR and Mass spectral analysis. The isolated phytosterols (β-sitos-terols) were then subjected to microbial transformation which yielded a considerable amount of androsta-1, 4-diene-3,17-dione (ADD) in the incubation mixture in presence of metabolic inhibitors (α, α＇-dipyridyl and sodium arsenate).

乳化植物甾醇对福建白兔生长性能、肠道形态及盲肠菌群与代谢物的影响

本试验旨在研究乳化植物甾醇对福建白兔生长性能、肠道形态及盲肠菌群与代谢物的影响。选取健康、体重相近的40日龄福建白兔150只,随机分为5组,每组30只(公母各占/1/2),单笼饲养。对照组饲喂基础饲粮,试验组A在基础饲粮中添加20 mg/kg的普通植物甾醇,试验组B、C、D在基础饲粮中分别添加10、20和40 mg/kg的乳化植物甾醇,试验期为60 d。饲养试验结束后采样,测定各组的生长性能和肠道形态、盲肠菌群组成与代谢物组成及相对含量。结果显示:1)与对照组和试验组A相比,试验组B、C、D福建白兔的腹泻率和死亡率明显下降,平均日采食量、平均日增重、料重比等各项生长性能指标均有一定程度的改善,其中试验组C的平均日增重、料重比与其他各组的差异达到显著水平(P<0.05)。2)与对照组相比,试验组C的十二指肠绒毛长度与试验组B、C的空肠绒毛长度显著提高(P<0.05),试验组A、B、C、D十二指肠的隐窝深度与试验组B、C、D空肠的隐窝深度显著降低(P<0.05),试验组A、B、C、D十二指肠和空肠的绒毛长度与隐窝深度比值(V/C值)与试验组B、C、D回肠的V/C值显著增加(P<0.05);试验组A空肠、回肠的V/C值显著低于试验组B、C、D(P<0.05);试验组C十二指肠的绒毛长度、试验组C、D十二指肠的V/C值显著高于其他各组(P<0.05)。3)试验组B、C、D盲肠菌群组成与对照组和试验组A相差较大,试验组B、C、D在门水平上以厚壁菌门(Firmi-cutes)、拟杆菌门(Bacteroidota)为主,厚壁菌门/拟杆菌门随着乳化植物甾醇添加剂量的增加呈现先增加后略微下降的趋势;在属水平上,Muribaculaceae、瘤胃球菌科NK4A214组(Ruminococ-caceae_NK4A214_group)、阿克曼氏菌属(Akkermansia)、梭菌纲UCG014(Clostridia_UCG-014)、梭菌纲vadinBB60组(Clostridia_vadinBB60_group)为各组优势菌属。4)添加植物甾醇的各试验组盲肠中糖和醇、有机酸、氨基酸等代谢物的相对含量比对照组增加,部分脂类和类脂类的相对含量下降,类激素物质的相对含量增加。Spearman相关性分析表明,这些代谢物与产粪甾醇真杆菌属(Eubacterium_coprostanoligenes)和瘤胃球菌科V9D2013组(Ruminococcaceae_V9D2013_group)密切相关。综上所述,饲粮中添加乳化植物甾醇可降低福建白兔的腹泻率和死亡率,提高平均日采食量和平均日增重,降低料重比,有利于改善肠道形态和盲肠菌群组成,增加盲肠中代谢物的相对含量,特别是短链脂肪酸;乳化植物甾醇添加剂量为20 mg/kg时对福建白兔生长性能和肠道黏膜形态完整性的改善效果最好,此剂量为福建白兔饲粮中的乳化植物甾醇的最佳添加剂量。

植物甾醇的生物学功能及其对动物生产、经济效益影响的研究进展

植物甾醇是以环戊二烯菲为骨架的3-羟基类化合物,主要以游离态、酯化态和糖苷3种形式存在于植物细胞膜中。植物甾醇是甾体化合物、VD及多种激素合成的前体物质,广泛存在于油类、蔬菜、水果、坚果、豆类及薯类等植物中。植物甾醇主要包括β-谷甾醇、豆甾醇、菜油甾醇等,具有胆固醇结构。植物甾醇具有多种生物学功能,如调节免疫、降低胆固醇、抗炎、抗氧化、促生长、预防心脑血管疾病等,可以提高动物机体的抗氧化能力及免疫力,改善血脂代谢,提高生产性能,改善畜产品品质,提高养殖的经济效益。为了使植物甾醇更好地应用于动物养殖中,文章综述了植物甾醇的理化性质、活性功能及其在动物养殖中的研究进展,为其在动物生产中的进一步推广与应用提供参考。

植物甾醇提取纯化方法研究进展

为了提高植物甾醇的提取效率和纯度,对植物甾醇的结构和来源,提取纯化方法及其辅助技术的原理、种类、特点以及应用等进行归纳分析,并对今后的研究方向提出了建议。植物甾醇来源广泛,但传统的植物甾醇提取纯化方法如溶剂萃取法等存在收率低、纯度低以及影响环境等缺点,具有一定局限性。新型的植物甾醇提取纯化方法如超临界CO_(2)法等具有操作简单、无毒、产品纯度高等优点,是一种环保高效的提取方法。辅助提取技术如酶、微波、超声波和磁场等能够优化对植物甾醇的提取纯化工艺,提高提取纯化效率。通过将传统方法进行改良、与新型方法结合、优化工艺参数以及开发新的提取纯化技术等措施,实现植物甾醇的高效提取纯化。

植物甾醇对O/W型纳米乳液物化稳定性及消化特性的影响

植物甾醇(PS)具有不溶于水,难溶于油的特性,构建水包油(O/W)型纳米乳液是目前提升其生物利用度、感官品质的常见方法,然而其乳化作用对O/W型纳米乳液的稳定机制尚未得到关注。本研究构建了荷载不同质量分数的植物甾醇(0.1%,0.5%,0.9%)的纳米乳液(PSN),系统探究了PS浓度对油-水界面张力,以及乳液的微观结构、粒径、ζ-电位、储藏稳定性、氧化稳定性以及消化特性的影响。结果表明:PS可降低油-水界面张力,并可在界面处形成部分结晶,影响PSN的物化稳定性;制得的PSN粒径为165.3~247.2 nm,ζ-电位范围为-24.3~-28.4 mV,随着PS浓度的增加逐渐增大;4℃储存28 d,0.1%PSN及0.5%PSN均可保持良好的稳定性,然而在60℃储存条件下,0.9%PSN表现出最优的动力学稳定性。此外,加速氧化试验及消化试验的结果均显示,较高浓度的PS可有效抑制乳液中的脂质氧化以及游离脂肪酸的释放(<31.41%)。本研究结果可为PS功能性食品或辅料的精准开发提供较好的理论参考。

植物油脱臭馏出物的组成及品质分析

旨在为植物油脱臭馏出物(DD油)相关标准的制定以及产品的开发提供参考,收集了全球35个不同工厂来源大宗油料的DD油,对其理化指标、不皂化物和危害因子进行分析。结果表明:35个DD油样品的酸值(KOH)为68.1~191.3 mg/g,过氧化值为0.043~0.149 g/100 g,水分及挥发物含量为0.18%~1.98%,灰分含量均小于0.3 g/100 g,皂化值(KOH)为125.0~205.8 mg/g,不皂化物含量为2.80%~35.71%;DD油样品的植物甾醇含量为0.81%~18.23%,维生素E含量为0.13%~9.23%,角鲨烯含量为0.09%~2.56%;DD油样品中PAH4总含量为6.74~61.98μg/kg,6种邻苯二甲酸酯(DEP、DMP、DIBP、DBP、BBP、DEHP)总含量为1.12~17.57 mg/kg。不同DD油理化指标、维生素E和植物甾醇含量存在较大差异,且样品中多环芳烃和塑化剂的污染水平较高,在DD油相关标准的制定及产品开发的过程中应给予必要的关注。

基于植物甾醇与γ-谷维素的牡丹/葵花籽油凝胶的制备及其物理特性研究

凝胶剂的含量和比例、植物油基质是影响油凝胶结晶特性和加工功能的重要因素。该研究以植物甾醇和γ-谷维素为凝胶剂,牡丹籽油和葵花籽油为基质油制备高含量α-亚麻酸油凝胶,探讨了植物甾醇与γ-谷维素的质量比以及基质油对油凝胶外观、硬度、黏度、微观结构、流变和热力学性质的影响。结果表明,在4℃下,当m(植物甾醇)∶m(γ-谷维素)=40∶60,添加量为8%(质量分数)时,油凝胶形成的速度最快,硬度和黏度最大,熔点也最高;与葵花籽油凝胶相比,此条件下牡丹籽油凝胶的硬度更大(210.70 N),凝胶时间更短(0.5 h),熔点更高(55.22℃)。油凝胶制备时,可通过调整植物甾醇与γ-谷维素的比例来获得所需的晶型和凝胶网络结构,并由此获得理想的硬度、黏度、熔点和透明度等,以适应特定食品加工的需求。该研究为后续基于油凝胶的新型功能黄油和功能奶油的制备提供了理论基础。

番茄红素、叶黄素和植物甾醇联合应用对绝经后骨质疏松症小鼠肠道菌群的影响

目的:探索番茄红素、叶黄素和植物甾醇联合应用对绝经后骨质疏松症小鼠肠道菌群的影响。方法:采用双侧去卵巢(OVX)法建立绝经后骨质疏松模型,将60只12周龄雌性C57BL/6J小鼠随机分为假手术组(sham组),OVX组,番茄红素、叶黄素和植物甾醇联合干预低剂量(L)、中剂量(M)、高剂量(H)组,戊酸雌二醇组(E2组),每天1次灌胃给药,持续12周。Micro-CT扫描分析小鼠股骨骨密度(BMD)和骨微结构变化;苏木精—伊红(HE)染色观察各组股骨组织病理学改变;酶联免疫吸附试验(ELISA)检测股骨中骨钙素(BGP)和抗酒石酸酸性磷酸酶5b(TRAP5b)的表达;16S rDNA扩增子测序检测分析粪便中V3~V4区菌群基因。结果:HE结果显示,OVX组小鼠骨松质结构改变,骨小梁稀疏松散、粗细不匀,大量断裂,骨髓腔间距宽;M组、H组的骨结构改善,且H组接近于sham组;Micro-CT结果显示,与sham组相比,OVX组的BMD、小梁体积百分比(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁数(Tb.N)和连接密度(Conn.Dn)显著降低,骨表面积/组织体积(BS/TV)、骨小梁空隙(Tb.SP)、结构模型指数(SMI)显著增加;与OVX组相比,M组和H组BMD、BV/TV、BS/TV、Tb.N、Conn.Dn显著增加,H组Tb.Sp、SMI显著降低;ELISA结果显示,与OVX组相比,M组、H组的BGP显著升高,TRAP5b显著降低。16S r DNA扩增子测序结果显示,在门水平上,H组的疣微菌门相对丰度较OVX组明显增加,拟杆菌门相对丰度较OVX组降低;在属水平上,H组艾克曼菌属、毛螺菌科_NK4A136菌属、双歧杆菌属、回肠杆菌属和毛螺旋菌属的相对丰度较OVX组升高,杜氏杆菌属、乳酸杆菌属、螺杆菌属和另枝菌属的相对丰度较OVX组降低;线性判别分析效应(LEf Se)分析结果显示,H组中的放线菌门、放线菌门未确定菌纲、双歧杆菌目、双歧杆菌属、双歧杆菌科、Ileibacterium valens和回肠杆菌属丰度富集。结论:番茄红素、叶黄素和植物甾醇联合应用可以明显改善OVX小鼠骨微结构,缓解骨丢失,其机制可能与调控肠道菌群结构和丰度相关。

植物甾醇酯的生物活性及其运载体系研究进展

植物甾醇酯具有降胆固醇、抗氧化、抗心血管疾病等多种生理功能,然而稳定差、水溶性差以及生物利用率低等缺点限制了其在食品、医药以及化妆品领域的应用,因此选择合适的运载体系对其进行递送以拓宽其应用是目前重要的研究方向。对植物甾醇酯的理化性质和生物活性进行总结,并综述了多种运载体系递送植物甾醇酯的研究进展,提出现有运载体系存在的一些问题以及改进方法,以期为植物甾醇酯新型运载体系的研究提供思路。