植物甾醇酯--一种新型的降胆固醇健康食品

植物甾醇是一种新型的降胆固醇健康食品,是国际生命科学学会推荐的十大功能性食品之一.而植物甾醇一般是以甾醇酯的形式应用于食品中.概述了植物甾醇酯的降胆固醇效果、作用机制、性质及应用,以及对它的安全性评价等.     

植物甾醇性质、功能、安全性及其食品的研究进展

植物甾醇是天然安全的活性物质,广泛存在于植物油、坚果、种子和谷物中。主要论述了植物甾醇的结构、性质、降胆固醇作用、抗癌作用、抗氧化作用等生理功能及安全性风险评估,以及植物甾醇功能性食品的研究与开发。     

食品加工对植物甾醇的影响

血脂过高引起的心血管病已成为威胁人类健康的第一杀手，植物甾醇因其具有显著的降血脂作用而倍受关注。论述了植物甾醇的天然来源、存在形式及食品加工对其影响，以利于控制食品加工条件，最大限度地使甾醇得到保留。     

植物甾醇的提取、生理功能及在食品中的应用综述

本文主要介绍了植物甾醇的相关性质、功能及在食品中的应用,综述了在油脂加工副产物中甾醇的含量与提取,包括在副产物油脚中甾醇的含量与提取率;不同来源的副产物脱臭馏出物中甾醇的含量、主要甾醇成分及提取工艺等。介绍了植物甾醇的特殊功能(如降低胆固醇、减少冠心病发生、抗氧化等)及在食品中的广泛应用。天然植物甾醇在食品体系中添加时经常会出现结晶现象,且在水相和油相中溶解度低。为能在食品中广泛应用,常采用植物甾醇改性将其转变成甾醇酯的方式添加到食品中。文中介绍了植物甾醇改性的不同工艺并得到了较好的效果。在特殊的环境条件下,天然甾醇会发生氧化产生甾醇氧化产物。文中介绍了不同储藏条件甾醇氧化产物的含量及主要成分、甾醇氧化稳定性与结构的关系以及对主要慢性病的发生和发展的促进作用等。     

植物甾醇的提取、生理功能及在食品中的 应用综述

本文主要介绍了植物甾醇的相关性质、功能及在食品中的应用等。综述了在油脂加工副产物中甾醇的含量与提取：包括在副产物油脚中甾醇的含量与提取率;不同来源的副产物脱臭馏出物中甾醇的含量、主要甾醇成分及提取工艺等。介绍了植物甾醇的特殊功能（如降低胆固醇、减少冠心病发生、抗氧化等）及在食品中的广泛应用。天然植物甾醇常在食品体系中添加时出现结晶现象,且在水相和油相中溶解度低,为能在食品中广泛应用,常采用植物甾醇改性将其转变成甾醇酯的方式添加到食品中。文中介绍了植物甾醇改性的不同工艺并得到了较好的效果。在特殊的环境条件下,天然甾醇会发生氧化产生甾醇氧化产物。文中介绍了不同储藏条件甾醇氧化产物的含量及主要成分、甾醇氧化稳定性与结构的关系以及对主要慢性病的发生和发展的促进作用等。     

植物甾醇的研究进展

研究发现,植物甾醇能同时降低血清中总胆固醇含量和低密度脂蛋白胆固醇水平,并在2010年被我国批准为新资源食品。文中简要介绍了植物甾醇的性质、来源及生理功能,总结了典型的植物甾醇分离提取工艺,并综述了植物甾醇的改性研究和甾醇氧化产物研究进展,重点阐述了天然植物甾醇及其氧化物的安全性问题,为甾醇的工业应用提供一定的借鉴作用。     

植物甾醇酯合成工艺研究进展

植物甾醇为植物油中的一种天然组分,植物甾醇中主要包括β-谷甾醇、豆甾醇等一类以环戊烷全氢菲为骨架的天然生理活性物质,能够有效抑制肠道对外源性胆固醇的吸收,从而降低血清中总胆固醇的水平。而植物甾醇酯(PE)是它的酯化产物,与植物甾醇相比具有更佳的脂溶性和更优的降血清胆固醇功效,可作为一类具有降低血清胆固醇、预防心血管疾病等功效的新型功能食品添加剂。而植物甾醇酯与植物甾醇相比,能比较方便地添加到油脂或含油脂的食品中。本文介绍了植物甾醇酯合成的研究概况,并阐述了化学法、酶法、离子液体法、无溶剂直接酯化法合成植物甾醇酯,为研发高效、环保、可靠、安全的植物甾醇酯提供参考,同时也为进一步的研究植物甾醇酯的合成技术提供参考意见。     

植物甾醇中汞检验方法的改进

植物甾醇是从玉米、大豆中经过物理提纯而得。该物质具有抗炎、抗癌、治疗溃疡及保护心脑血管等功效。此外,植物甾醇还是重要的甾体药物和维生素D3的生产原料,如今已广泛应用在食品、医药等领域。因此,植物甾醇中汞含量的检测具有必要性。     

甾醇氧化特性及其在食品中应用研究进展

植物甾醇具有降低胆固醇等生物学效应。本文在概述植物甾醇的功能特性和食用安全性的基础上,对其氧化产物的形成机制及特性、检测方法研究进展以及功能性甾醇食品的开发现状进行综述,针对中餐食用油以高温煎炸为主的食用习惯,对我国功能性甾醇食品的研究与开发提出建议。     

植物甾醇酯降血脂作用的研究

研究植物甾醇酯的降血脂作用。饲喂高脂饲料，建立高血脂动物模型，然后饲喂添加了植物甾醇酯的高脂饲料；同时用添加植物甾醇酯的高脂饲料饲喂正常小鼠，探讨植物甾醇酯的降血脂作用。结果表明，植物甾醇酯可以降低高脂血症小鼠和饲喂高脂饲料的正常小鼠的血清总胆固醇和低密度脂蛋白胆固醇水平，从而使小鼠的HDL-C／LDL-C比值增加、动脉硬化指数减小。由此说明，植物甾醇酯有明显的降血脂作用，可以作为高脂血症和动脉粥样硬化患者的疗效食品和喜食高脂食品人群的保健食品。     

植物甾醇烟酸酯研究与开发

植物甾醇烟酸酯结合植物甾醇和烟酸治疗高血脂特点,具有治疗范围广、疗效显著、应用性能良好等独特优点,可成为一种新的降低血清胆固醇功能性食品添加剂,并有望进一步开发成一种安全的、用于治疗高血脂疾病新型药物,具有广泛用途和良好应用前景。该文还对植物甾醇烟酸酯合成方法进行介绍。     

植物甾醇降胆固醇作用研究进展

植物甾醇属于甾体类化合物,具有多种生理功能.讨论了植物甾醇的化学特性、主要来源、吸收与代谢,并对其降胆固醇作用的研究进展及作用机理进行了综述,最后对其安全性进行了评价,并分析了其应用前景.     

植物甾醇的提取分离和分析检测方法研究进展

植物甾醇因其具有降低血清胆固醇等多种生物活性功能越来越受到人们的重视,并随着在医药等工业上进一步应用对其纯度也提出更高要求.因此如何从植物油脂中提取甾醇类物质以及进一步分离纯化和分析测定其含量和结构成为当前植物甾醇研究的重点.本文较全面地对传统和现代的植物甾醇的提取分离、纯化精制以及分析检测方法进行综述,希望对今后植物甾醇的研究会有所帮助.     

食品中植物甾醇的色谱分析方法研究进展

植物甾醇广泛分布于各种食用植物中,主要以游离态甾醇、甾醇酯、甾醇糖苷和脂酰基甾醇糖苷形式存在,具有抗炎、抗菌、抗真菌、降低胆固醇、抗肿瘤等功效。本文综述了近些年关于植物甾醇色谱检测方法的研究进展。植物甾醇常用样品前处理手段有液液萃取、薄层色谱、高速逆流色谱和超临界萃取等,而植物甾醇检测方法主要采用气相色谱法和液相色谱法,其中气相色谱法检测甾醇的灵敏度较高,但液相色谱法具有柱温温和、不破坏样品的特性,适合检测热不稳定植物甾醇。气相色谱法或液相色谱法与质谱检测器联用技术在多组分植物甾醇的同时定量方面取得了一定进展。     

植物甾醇提取及分析检测方法研究进展

植物甾醇广泛存在于植物界中,是一类具有较强的生理活性和表面活性的物质,其在医药、食品、化妆品、光学产品、饲料、化工、纺织等领域的应用也受到广泛关注。较全面地对植物甾醇的提取、分离以及分析检测方法进行了综述,以期对今后植物甾醇的研究提供借鉴。     

Phytosterols as anticancer compounds

Phytochemicals have been proposed to offer protection against a variety of chronic ailments including cardiovascular diseases, obesity, diabetes, and cancer. As for cancer protection, it has been estimated that diets rich in phytochemicals can significantly reduce cancer risk by as much as 20%. Phytosterols are specific phytochemicals that resemble cholesterol in structure but are found exclusively in plants. Phytosterols are absorbed from the diet in small but significant amounts. Epidemiological data suggest that the phytosterol content of the diet is associated with a reduction in common cancers including cancers of the colon, breast, and prostate. The means by which dietary phytosterols may be achieving these effects is becoming clearer from molecular studies with tumorigenic research models. Phytosterols affect host systems potentially enabling more robust antitumor responses, including the boosting of immune recognition of cancer, influencing hormonal dependent growth of endocrine tumors, and altering sterol biosynthesis. In addition, phytosterols have effects that directly inhibit tumor growth, including the slowing of cell cycle progression, the induction of apoptosis, and the inhibition of tumor metastasis. This review summarizes the current state of knowledge regarding the anticancer effects of phytosterols.     

Development and Characterization of Phytosterol-Enriched Oil Microcapsules for Foodstuff Application

Phytosterols are lipophilic compounds contained in plants and have several biological activities. The use of phytosterols in food fortification is hampered due to their high melting temperature, chalky taste, and low solubility in an aqueous system. Also, phytosterols are easily oxidized and are poorly absorbed by the human body. Formulation engineering coupled with microencapsulation could be used to overcome these problems. The aim of this study was to investigate the feasibility of encapsulating soybean oil enriched with phytosterols by spray-drying using ternary mixtures of health-promoting ingredients, whey protein isolate (WPI), inulin, and chitosan as carrier agents. The effect of different formulations and spray-drying conditions on the microencapsules properties, encapsulation efficiency, surface oil content, and oxidation stability were studied. It was found that spherical WPI-inulin-chitosan phytosterol-enriched soybean oil microcapsules with an average size below 50 μm could be produced with good encapsulation efficiency (85%), acceptable level of surface oil (11%), and water activity (0.2–0.4) that meet industrial requirements. However, the microcapsules showed very low oxidation stability with peroxide values reaching 101.7 meq O₂/kg of oil just after production, and further investigations and optimization are required before any industrial application of this encapsulated system.     

Distribution and retention of phytosterols in frying oils and fried potatoes during repeated deep and pan frying

The retention and distribution of phytosterols in fried oils and French-fries during eight successive pan- and deep-frying sessions of pre-fried potatoes in sunflower oil, palm oil, cottonseed oil, virgin olive oil and a vegetable shortening were evaluated. Phytosterols (β-sitosterol, campesterol, stigmasterol, Δ⁵-avenasterol) were determined in the unsaponifiable fraction of frying oils and lipids extracted from French-fries by GC/FID after derivatization to trimethylsilyl ethers. French-fries were enriched with phytosterols due to the absorption of frying oil, with β-sitosterol predominating in both fried oils and potatoes. The amount of phytosterols decreased during frying, their overall retentions reaching 9.5–22.8% and 29.4–51.2% after eight successive pan- and deep-frying sessions, respectively, while their deterioration was found to be affected by frying time, frying technique, being more prolonged during pan-frying, and by the oils’ unsaturation, being more extended in polyunsaturated oils. Phytosterols were more or less uniformly distributed between the fried oil and the fried potatoes. The phytosterols dietary intake by consuming potatoes fried in the oils tested is discussed.     

Current Knowledge about Oxysterols: A Review

For years food consumers have been warned that a cholesterol‐rich diet may result in atherosclerosis. It is also well known that consumption of large amounts of phytosterols decreases concentration of low‐density lipoproteins (LDLs) in blood (LDLs are regarded a key risk factor in development of cardiovascular diseases). However, no scientific evidence has unambiguously proved any direct connection between amount of consumed cholesterol and LDL level in blood. On the other hand, concentration of cholesterol oxidation products, oxysterols, seems to be indeed relevant; for example, they significantly impact appearance of atherosclerotic lesions (plaques). Phytosterols (like sitosterol or campasterol) decrease LDL level in blood, but on the other hand products of their oxidation are toxic. Therefore, it is worth to know influence of phytosterols on living organisms, processes which lead to their formation, and their levels in popular foodstuffs. This paper is an attempt to review literature data on the above aspects, as well as on impact on living organisms of oxidation products of popular sterols.     

植物甾醇生理功能及其研究进展

就植物甾醇中最主要的生理功能一降低血清胆固醇的研究与开发方面的历史和最新进展进行了综述，并对其作用机理、安全性评价作了介绍。