苹果渣中苹果多酚的提取工艺优化

采用有机溶剂提取法从苹果渣中提取苹果多酚,研究了提取溶剂乙醇体积分数、料液比、提取温度、提取时间对苹果多酚提取量的影响。通过单因素实验及正交实验确定苹果多酚的最佳提取工艺条件为:提取溶剂乙醇体积分数70%、料液比1∶25(g∶mL)、提取温度30℃、提取时间40min,此条件下苹果多酚的提取量为2.982mg.g-1。     

不同苹果中果皮、果肉、果核多酚物质的提纯与比较

苹果多酚具有抗氧化衰老、降低血糖血脂、减重减肥等功效,苹果多酚应用的领域非常广阔,应用前景很大,本文对不同品种的苹果的果皮、果肉、果核进行多酚提取与比较,嘎啦果、红蛇果和红富士三种苹果中果皮所含的多酚物质高于果核和果肉,红蛇果的果皮中多酚物质含量最高,可以将红蛇果果皮中的多酚物质提取出来,有效降低成本,更好利用于其他领域。     

苹果多酚提取物对酪氨酸酶的抑制作用

分别以L-酪氨酸和L-多巴(二羟基苯丙氨酸)为底物,在37℃,pH=6.8的磷酸盐缓冲体系中,测定了苹果多酚提取物对酪氨酸酶单酚酶活性和二酚酶活性的抑制效应。结果表明,苹果多酚提取物可有效抑制酪氨酸酶单酚酶活性,其IC50为1.96 mg·L-1。同时,苹果多酚提取物还是较强的二酚酶抑制剂,在实验质量浓度范围(0.012 5~1.75 g·L-1)内,苹果多酚提取物对酪氨酸酶二酚酶的抑制率最高可达73.66%,IC50为36.28 mg·L-1。L-多巴氧化体系动力学分析结果表明,苹果多酚提取物在低质量浓度下对酪氨酸酶表现为非竞争性抑制类型,而在高质量浓度下则表现为混合性抑制类型。     

苹果生果中苹果多酚提取工艺的优化研究

采用响应面法,对苹果生果中多酚的提取工艺进行了优化设计,建立了提取苹果多酚的二阶响应回归模型,分析了主要工艺参数的影响及其交互作用。结果表明,提取总酚的最佳工艺条件为:温度94.4℃、浸提时间10.68 min、液料比30.2 mL/g,其最终提取率为108.6 mg/g。     

不同型号大孔树脂对苹果多酚物质的吸附特性

通过进行静态和动态吸附实验,研究了不同型号大孔树脂对红富士苹果多酚的吸附特性。各型号大孔树脂的静态与动态吸附性能及解析率不同,但差异不显著(p0.05),且吸附及解析规律基本一致,其吸附及解析性能顺序为XDA-5AB-8D-101XDA-7;XDA-5大孔树脂静态和动态吸附性能和解析性能均最好,其静态解析率和动态解析率分别达(69.281±0.214)%和(73.585±0.499)%;XDA-5大孔树脂对苹果多酚的静态和动态吸附性能均比其他类型树脂好,且XDA-5对苹果多酚的动态吸附的吸附量和解析率均较静态吸附更高。     

利用苹果皮多酚制备具抗氧化性防晒霜

本实验提取苹果皮中多酚,研究其抗氧化性和防晒能力,利用其特殊的理化性质制备O/W型防晒霜,同时对比不同苹果皮多酚含量的防晒霜的防晒能力。实验证明,苹果多酚具有较好的抗氧化性和防晒能力,加入约2%多酚为配制该防晒的最优含量,该产品SPF约为27.61。     

不同存储温度对苹果多酚和黄酮类化合物含量的影响

研究了随着时间的延长贮藏温度对红富士苹果多酚和黄酮类化合物含量的影响规律。结果表明,随着时间的延长,富士苹果中总酚和黄酮含量降低,且差异显著(p≤0.01),存储于4℃下的苹果总酚和黄酮含量低于存储在常温条件(20±2)℃下。     

不同存储温度对苹果多酚和黄酮类化合物含量的影响

研究了随着时间的延长贮藏温度对红富士苹果多酚和黄酮类化合物含量的影响规律。结果表明,随着时间的延长,富士苹果中总酚和黄酮含量降低,且差异显著(p≤0.01),存储于4℃下的苹果总酚和黄酮含量低于存储在常温条件(20±2)℃下。     

三种天然植物活性成分在卷烟中的应用

从天然植物粗提物中分离的天然植物活性物质成分纯度高,质量易于控制,应用于卷烟有一定的优势。因此,对甘草、茉莉及苹果的活性成分进行了分离纯化,并对比评吸了三种天然植物活性成分及天然植物粗提物在卷烟中的应用效果,结果表明:甘草酸作为烟草添加剂保持了甘草提取物作为烟草添加剂的优点,同时消除了甘草中其他物质带来的杂气刺激等不良影响;茉莉总黄酮作为烟草添加剂与茉莉提取物相比,保留了提取物的部分优点,但同时消除了刺激残留的问题;苹果多酚与苹果提取物作为烟草添加剂增香作用明显。     

苹果多酚防晒霜的研制

提取了苹果中的多酚成份,并对其防晒性能进行了研究,并和纳米二氧化钛、纳米氧化锌、新型防晒剂NT-200A、新型防晒剂NT-200B等紫外线屏蔽剂进行复合使用,研究其复合防晒性能。结果显示,多酚具有一定的防晒功能,加入其它防晒剂复配后制成防晒霜,得到较为理想的防晒产品。     

Heat and Mass Transfer Modeling of Apple Slices Under Simultaneous Infrared Dry Blanching and Dehydration Process

To develop a new simultaneous infrared dry blanching and dehydration process for producing high-quality blanched and partially dehydrated products, apple slices with three different thicknesses, 5, 9, and 13 mm, were heated using infrared for up to 10 min at 4000 W/m² IR intensity. The surface and center temperatures, moisture change, and enzymatic activities of polyphenol oxidase (PPO) and peroxidase (POD) of apple slices were determined. The models of heat and mass transfer and enzyme inactivation were developed for predicting the blanching and dehydration performance. In the model development, the apple slices were assumed as one dimensional with heat and mass transfer only occurring in one direction. The enzyme inactivation followed first-order kinetics. The models were solved using a finite element method. The predicted temperature and moisture profiles and inactivation rate of enzymes were found to be in good agreement with the experimental data. This indicated that the process of simultaneous dry blanching and dehydration of apple slices under IR heating can be predicted with the developed models.     

The effect of an apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers on brachial artery flow-mediated vasodilatory function in volunteers with elevated blood pressure

Background

The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).

Methods

This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.

Results

With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.

Conclusions

A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.

Trial registration

The trial is registered at http://clinicaltrials.gov (identifier: NCT01690676). Registered 25th May 2012.

     

Genome-Wide Analysis of the Apple CBL Family Reveals That Mdcbl10.1 Functions Positively in Modulating Apple Salt Tolerance

Abiotic stresses are increasingly harmful to crop yield and quality. Calcium and its signaling pathway play an important role in modulating plant stress tolerance. As specific Ca²⁺ sensors, calcineurin B-like (CBL) proteins play vital roles in plant stress response and calcium signaling. The CBL family has been identified in many plant species; however, the characterization of the CBL family and the functional study of apple MdCBL proteins in salt response have yet to be conducted in apple. In this study, 11 MdCBL genes were identified from the apple genome. The coding sequences of these MdCBL genes were cloned, and the gene structure and conserved motifs were analyzed in detail. The phylogenetic analysis indicated that these MdCBL proteins could be divided into four groups. The functional identification in Na⁺-sensitive yeast mutant showed that the overexpression of seven MdCBL genes could confer enhanced salt stress resistance in transgenic yeast. The function of MdCBL10.1 in regulating salt tolerance was also verified in cisgenic apple calli and apple plants. These results provided valuable insights for future research examining the function and mechanism of CBL proteins in regulating apple salt tolerance.     

Dose-dependent hypocholesterolemic actions of dietary apple polyphenol in rats fed cholesterol

The dose-dependent hypocholesterolemic and antiatherogenic effects of dietary apple polyphenol (AP) from unripe apple, which contains approximately 85% catechin oligomers (procyanidins), were examined in male Sprague-Dawley rats (4 wk of age) given a purified diet containing 0.5% cholesterol. Dietary AP at 0.5 and 1.0% levels significantly decreased the liver cholesterol level compared with that in the control (AP-free dietfed) group. Dietary AP also significantly lowered the serum cholesterol level compared with that in the control group. However, the HDL cholesterol level was significantly higher in the 1.0% AP fed group than in the control group. Accordingly, the ratio of HDL-cholesterol/total cholesterol was significantly higher in the 0.5% AP-fed group and 1.0% AP-fed group than in the control group. Moreover, the atherogenic indices in the 0.5 and 1.0% AP-fed groups were significantly lower than those in the control group. The activity of hepatic cholesterol 7α-hydroxylase tended to be increased by dietary AP in a dose-dependent manner. In accord with this observation, dietary AP increased the excretion of acidic steroids in feces. Dietary AP also significantly promoted the fecal excretion of neutral steroids in a dose-dependent manner. These observations suggest that dietary AP at 0.5 or 1.0% level exerts hypocholesterolemic and antiatherogenic effects through the promotion of cholesterol catabolism and inhibition of intestinal absorption of cholesterol.     

苹果园的测土配方施肥技术

在一定的目标产量区间里,苹果园氮、磷、钾肥的施用量与土壤中氮、磷、钾养分含量呈负的线性关系：根据烟台地区苹果生产实践,总结提出了养分施用量与土壤养分含量、目标产量的线性函数公式,可方便求得苹果的适宜基、追施N、P2O5、K2O量。     

INFLUENCE OF SOLUTE TEMPERATURE AND CONCENTRATION ON THE COMBINED OSMOTIC AND AIR DRYING

The effect of solute concentration (15-45 % sugars) and temperature (10-40 °C) on the osmotic dehydration of apple was investigated. Cylindrical samples of apple were immersed in glucose or sucrose solutions and the water loss, the volume of solids and the porosity were measured as a function of time. Water loss was proportional to the square root of time, while the volume of solids decreased and the porosity increased with time. Sugar gain and water loss decreased the compression stress of the apple samples. Osmotic pre-treatment reduced the shrinkage and the porosity of apple solids during air-drying, compared to the no-treated samples. The results of this investigation are useful in the design of efficient osmotic dehydration processes, and in the evaluation of texture of dehydration of products.     

INFLUENCE OF SOLUTE TEMPERATURE AND CONCENTRATION ON THE COMBINED OSMOTIC AND AIR DRYING

ABSTRACT

The effect of solute concentration (15–45 % sugars) and temperature (10–40 °C) on the osmotic dehydration of apple was investigated. Cylindrical samples of apple were immersed in glucose or sucrose solutions and the water loss, the volume of solids and the porosity were measured as a function of time. Water loss was proportional to the square root of time, while the volume of solids decreased and the porosity increased with time. Sugar gain and water loss decreased the compression stress of the apple samples. Osmotic pre-treatment reduced the shrinkage and the porosity of apple solids during air-drying, compared to the no-treated samples. The results of this investigation are useful in the design of efficient osmotic dehydration processes, and in the evaluation of texture of dehydration of products.