苹果多酚的组成和功能特性研究现状与展望

苹果多酚是广泛存在于苹果中的次级代谢产物，主要包括5类组分，即：酚酸、黄烷三醇、黄酮醇类、二氢查尔酮类及花青素类。苹果多酚组成和含量与苹果品类种属密切相关，取决于与其相关的基因表达及催化相关组分合成、转化的一系列酶的表达水平和活性。苹果多酚的积累受到栽培方式、环境条件、果实成熟度和贮藏条件影响存在较大变异。苹果多酚组成的不同影响并决定其活性水平。苹果多酚的酚羟基、还原酮结构、原花青素的缩合结构赋予其强的抗氧化力，是苹果多酚功能性及应用的物质和结构基础。苹果多酚对食品加工中色泽、风味、质地的形成以及在食品保藏方面的应用已有较为深入的研究。苹果多酚的生理活性涉及的降血糖、降血脂，修复组织器官损伤，预防和抑制癌细胞增殖、迁移及凋亡，提高机体免疫和体能，促进毛发生长和皮肤活性方面的研究也已深入至机理层面。本文综述近年来苹果多酚的组成、生物合成、资源分布，食品加工功能性及生理生化功能性，为苹果多酚资源的挖掘和功能应用提供思路和借鉴。     

苹果多酚的特性及其应用

苹果多酚作为重要的生理活性物质,具有较强的抗氧化和抗肿瘤作用,已广泛应用于医学、食品等领域。本文通过对苹果多酚的性质、功能活性、应用方向的研究分析,指出加快苹果多酚研究及工业化生产的重要意义。     

苹果多酚的研究进展

从主要组成、提取纯化方法及主要生理活性三方面对苹果多酚的研究现状进行综述,为苹果多酚的进一步研究提供参考信息。     

苹果露中多酚物质的含量测定

利用HPLC法对苹果露中的生理活性成分进行含量测定。HPLC法采用Kromasil C18(4.6 mm×150 mm)色谱柱,流动相采用甲醇(A)-水(B)梯度洗脱,流速为1 mL/min,柱温为25℃,检测波长为290 nm,测定苹果露中儿茶素和原花青素B2的含量,苹果多酚采用分光光度法测定;结果表明:苹果露中儿茶素和原花青素B2的平均含量分别为26.77mg/L和45.43 mg/L,苹果多酚为2.92 mg/mL;儿茶素、原花青素B2和苹果多酚在苹果露中均能检测到,且含量较高,为人们饮用苹果露对人体的保健作用提供了理论依据。     

苹果多酚提取物抗氧化活性研究

测定各种苹果提取物中的总酚含量并研究其抗氧化活性。采用Folin—ciocaheau法测定各种苹果不同部位的总酚含量,从还原能力、抗氧化活性、抗脂质过氧化等方面对苹果多酚提取物的抗氧化活性进行比较研究。苹果多酚提取物具有较强的还原能力和抗氧化活性,对脂质过氧化产生的超氧阴离子自由基具有较强的抑制作用,且在试验浓度范围内其最大抑制率优于同浓度二丁基羟基甲苯的效果。苹果多酚提取物是一种优良的天然抗氧化剂和自由基清除剂。     

天然抗氧化剂——苹果多酚的研究与应用

苹果多酚是苹果中一种天然活性成分，具有很强的抗氧化能力和生理功能，可以广泛应用于食品和医药领域。本文主要介绍了苹果多酚的组成、性状、安全毒理、提取纯化方法、生理功能及其在食品中的应用等，并展望了其发展前景。     

响应曲面法优化微波辅助提取苹果渣多酚工艺研究

为从苹果渣中提取具有生理活性的多酚物质,在单因素试验的基础上,采用响应曲面法优化微波辅助提取苹果多酚的工艺,建立该工艺的二次多项数学模型,研究微波功率、提取时间、乙醇体积分数和料液比4个因素及其交互作用对提取工艺的影响.试验结果表明,对苹果多酚得率的影响次序是:微波功率>料液比>提取时间>乙醇体积分数;微波辅助提取苹果渣多酚的最佳工艺条件是:微波功率650W、提取时间53 s、乙醇体积分数60%、料液比1:20(g/mL),多酚得率迭61.8286 mg/100 g干果渣.     

苹果多酚与甲醛的反应特性及在鱿鱼丝加工中的应用效果研究

通过苹果多酚与甲醛反应特性的研究,探讨苹果多酚作为甲醛捕获剂的可能性。研究了不同pH、反应温度、反应时间及苹果多酚浓度对苹果多酚与甲醛反应的影响,并将苹果多酚应用于鱿鱼丝加工中对其捕获效果进行了验证。结果表明:pH、反应温度、反应时间及苹果多酚浓度对甲醛减少率均具有显著性影响(p0.05),碱性条件下苹果多酚与甲醛反应活性较高,随着反应温度的升高、反应时间的延长及苹果多酚浓度的增加,甲醛含量均显著减少。经苹果多酚处理的鱿鱼丝中甲醛初始含量及在30d贮藏期内甲醛含量增加量均显著(p0.05)低于对照组。苹果多酚在实际生产中对鱿鱼丝中甲醛具有良好的捕获效果。     

苹果多酚对小鼠的抗氧化作用研究

苹果多酚是一种优良、无毒的天然抗氧化剂,在未成熟的苹果和果渣中含量丰富.本文采用超声波提取法从苹果中提取苹果多酚,并通过动物试验确定其对小白鼠机体的抗氧化作用.结果表明,苹果多酚提取物可明显地提高其血清和组织SOD活性和降低MDA含量,显示出其具有较高的生物抗氧化作用.     

烫漂方式对苹果脆片褐变和多酚及其抗氧化活性的影响

为阐明烫漂方式对热风干燥苹果片品质特性的影响,采用热水、蒸汽和微波对苹果片进行烫漂处理,测定苹果片在烫漂和干燥过程中的色泽、多酚及其抗氧化活性的变化情况。结果表明,热水烫漂苹果片的干燥时间最短,为270 min;不同烫漂方式对苹果片褐变有显著影响(P<0.05),其中热水烫漂的苹果片色泽变化最小,微波烫漂的苹果片色泽最差;与鲜样相比,烫漂方式对苹果片还原糖含量影响较小;干燥过程中微波烫漂的苹果片中产生的5-羟甲基糠醛含量最高,蒸汽烫漂次之,热水烫漂最低;苹果片经热水烫漂和干燥后维生素C损失率分别为34%和52%,而蒸汽烫漂和微波烫漂的苹果片中维生素C损失率较小;热水烫漂的苹果脆片总酚含量最高,达到11.82 mg GAE/g DW;苹果片经烫漂处理后游离多酚和结合多酚单体无显著性变化(P>0.05),但干燥后,所有样品中结合多酚单体含量均显著提高(P<0.05)而游离多酚单体的含量无显著性变化(P>0.05),表明3种烫漂方式都有利于多酚单体的保留;多酚抗氧化能力实验表明烫漂和干燥后苹果片中结合多酚抗氧化活性有显著性变化(P<0.05),其中热水烫漂的苹果...     

苹果多酚的提取及其在食品中的应用现状分析

苹果多酚是一种新型的天然抗氧化剂，在未成熟的苹果和果渣中含量丰富。主要介绍了目前国内外对苹果中多酚类物质的研究现状，并概述了苹果多酚的各种提取方法，以及其在食品领域的应用现状。     

采收成熟度对烤烟多酚含量和组成的影响

分析了不同采收成熟度鲜烟叶和初烤烟叶的多酚类物质含量及其组成,结果显示:①中部烟叶以生理成熟的多酚含量最高,上部鲜烟叶多酚含量随采收成熟度增加而逐渐增加,上部初烤烟叶以工艺成熟的多酚含量最高;②欠熟鲜烟叶多酚中芸香苷含量最高,其他处理鲜烟叶和所有初烤烟叶多酚类物质组成为:绿原酸＞芸香苷＞4-O-咖啡奎尼酸＞新绿原酸＞山奈酚糖苷＞莨菪亭;③中、上部初烤烟叶多酚中绿原酸比例随采收成熟度的提高而增加,达到过熟时略有降低,而新绿原酸和4-O-咖啡奎尼酸比例与其相反,其他多酚类物质所占比例不同处理间差异不明显;④烤后烟叶多酚类物质含量均明显高于鲜烟叶,随着采收成熟度的提高,烤后烟叶多酚含量的增幅逐渐减小,初烤烟叶绿原酸类物质占多酚总量比例均高于其鲜烟叶,而芸香苷和山奈酚糖苷比例均明显低于其鲜烟叶.     

A profile of physicochemical and antioxidant changes during fruit growth for the utilisation of unripe apples

The physicochemicals associated with fruit quality, antioxidant activities and changes in polyphenol composition during Fuji apple growth were investigated from the 25th to 105th day after full bloom day (DAFB). Three kinds of antioxidant assays, including oxygen radical absorbing capacity (ORAC) were executed, and polyphenol composition were examined using HPLC. The change in weight of the Fuji apples during fruit growth showed a typical sigmoidal curve. Both the rise of the soluble solid content and the drop of the titratable acidity appeared to be more significant (p < 0.05) after the 85th DAFB. Concurrently, the antioxidant activities and the polyphenol content decreased (p < 0.05) rapidly after the same date. Accordingly, a profitable thinning date can be chosen around the 85th DAFB to utilise dropped unripe apples as resources of antioxidants. Furthermore, the antioxidant activities of Fuji apples may be highly affected by the chlorogenic acid content.     

Effect of Dipping Pre-treatment with Unripe Grape Juice on Dried “Golden Delicious” Apple Slices

The consumption of apple chips is increasing in the last decades because of the consumer’s preferences towards healthy snacks. However, the enzymatic browning, which is attributed mainly to polyphenol oxidase (PPO, EC 1.10.3.1) activity, negatively affects the sensory, nutritional, and antioxidant properties of dried apples as a consequence of the oxidation of phenolic substrates during post-harvest stages. The antibrowning and antioxidant effects of dipping pre-treatments with unripe grape juice as well as reference formulations including a mixture of 1% w/v ascorbic acid and 1% w/v citric acid, 6% w/v NatureSeal®, and 0.1% w/v sodium metabisulfite were evaluated by spectrophotometric and colorimetric assays on dried “Golden Delicious” apple slices. Based on HPLC analysis, the treated apple slices were enriched with bioactive compounds which effectively improved antioxidant capacity and limited enzymatic browning by increasing lightness, reducing color change, and inhibiting PPO activity. Hence, the juice of unripe grapes recovered as agricultural wastes during bunch thinning of vineyards could be proposed as a safe, inexpensive, and eco-friendly alternative to conventional antibrowning treatments in apple processing.     

苹果多酚抗氧化作用及其清除自由基能力的研究

苹果多酚是一类很强的抗氧化剂,具有较好清除自由基的作用.还有抗变异原性、防龋齿作用、抑制血压上升等生理功能,极具开发潜力.以猪油、芝麻油为底物,采用碘量法研究了苹果多酚的抗氧化性,结果表明,苹果多酚对油脂的脂质过氧化有良好的阻断作用,且抗氧化效果随其用量的增加而加强.在油脂中按油重的0.5％添加苹果多酚,可延长芝麻油出厂期4d,过氧化值为10.49 mmol/kg,抑制率达到36.78％;对猪油的抗氧化性在第6天时达到最大,抑制率达到61.78％.由此可见,苹果多酚对延长芝麻油的保质期有明显的功效,对植物油和动物油均有较明显的抗氧化作用.在此基础上,对苹果多酚清除DPPH自由基的动力学性质进行了研究,并与茶多酚比较其抗氧化能力.结果表明:苹果多酚清除DPPH自由基速度快,EC50值为0.07,而茶多酚的EC50值为0.075,表现出比茶多酚较强的抗氧化能力,具有良好的发展前景.     

石莼多酚的提取工艺、组成成分分析及生物活性评价的研究进展

石莼多酚是绿藻石莼（Ulva lactuca）的次级代谢产物,已被实验证实具有多种生物活性。石莼产生的多酚含量和生物活性不仅取决于生长环境和气候条件,还取决于提取方法和操作步骤。本文将对绿藻石莼中多酚物质的提取工艺、组成成分分析及生物活性中的抗氧化活性、抑菌活性、降胆固醇、抗炎作用以及体外抗癌活性的研究现状进行综述,介绍石莼多酚的应用前景,旨在为增加石莼多酚这种自然资源在食品、药品等领域中的应用提供理论依据。     

Polyphenol oxidase activity and implications on the quality of intermediate moisture and dried apples

This study aimed at investigating the water activity threshold for the polyphenol oxidase activity in Golden Delicious apple. Freeze-dried powders obtained from blanched and unblanched apples were equilibrated and stored at four water activity levels, ranging from 0.11 to 0.56, at 20 and 40 °C, to differentiate between nonenzymatic and enzymatic browning. The contents of hydroxycinnamic acids, phloridzin, catechin, epicatechin, polymeric flavan 3-ols, and 5-hydroxymethylfurfural, the antioxidant activity values, and the Hunter colorimetric parameters of apple products were analyzed. Results showed that no polyphenol oxidase activity occurred in unblanched dehydrated apples stored at water activity levels between 0.11 and 0.32. In this water activity range, blanching pre-treatment accelerated the Maillard reaction in the products stored at 40 °C, as observed from both higher 5-hydroxymethylfurfural formation and more intense red color development in blanched apples with respect to the unblanched ones. At the water activity level of 0.56, both increased redness and higher antioxidant degradation were observed in the unblanched apples with respect to the blanched apples, indicating that the threshold water activity for polyphenol oxidase was in the range 0.32–0.56. Among apple antioxidants, epicatechin was mostly affected by polyphenol oxidase activity, either by direct oxidation or by a coupled oxidation mechanism. Therefore, “mild” pre-heating treatments or no pre-treatments could be proposed when the apple is to be stored and used at water activity ≤0.32, whereas blanching should be applied for intermediate moisture apples or in food applications where moisture transfer from other ingredients could bring apples above this critical water activity level.     

苹果皮提取物的多酚组成及益生活性

苹果皮是生产苹果酱、果汁和其他产品的副产品,为探究其益生活性,该研究首先利用φ=80%丙酮作为溶剂得到苹果皮提取物（Apple Peel Extract,APE）,并采用高效液相色谱法对提取物的多酚组分进行分析。再通过体外益生菌厌氧发酵,跟踪测定24 h期间的生物量、pH值和多酚组分的变化。苹果皮提取物一共鉴定到13种多酚类物质,主要组分为根皮苷515.54 mg/100 g、金丝桃苷530.06 mg/100 g和槲皮苷459.04 mg/100 g。与空白组相比,APE显著促进了长双歧杆菌、嗜酸乳杆菌、副干酪乳杆菌和鼠李糖乳杆菌四种益生菌的增殖,其发酵液的pH值维持在3.66~4.00,降低了42.86%~47.71%。在发酵过程中,根皮苷分别被消耗了93.36%、89.21%、86.31%和0.41%。结果表明,苹果皮提取物拥有丰富的多酚单体组成,是一种潜在可利用的益生元,可以调节肠道益生菌生长及代谢,具有较高的益生活性。     

Functional components of grape pomace: their composition,biological properties and potential applications

The roles of functional foods on human health have been realised by more and more researchers, food producers and consumers. Functional food ingredients from both plant and animal sources such as dietary fibre, soy protein isolate, whey protein isolate and omega 3 fatty acid have been widely used in functional food product development. Many fruit processing by‐products such as grape, apple and orange peels are rich in bioactive phytochemicals, dietary fibre and unsaturated fatty acids, hence have potential to serve as functional food ingredients. In this review, we summarise recent advancement of research in grape pomace (GP), the residual of grapes after wine making. The polyphenol profile of GP and their biological, antioxidant and antimicrobial activities, the stability of GP polyphenols in food system, the interaction between GP polyphenol and other food ingredients, as well as the functionalities of grape seed oil and GP fibre are covered.