Subcritical water extraction of phenolic compounds from potato peel

Potato peel, a waste generated from potato processing, is a disposal problem. But, potato peel is a good source of functional ingredients such as phenolic compounds. This study investigated the extraction of eight phenolic compounds (Gallic acid, GAC; Chlorogenic acid, CGA; Caffeic acid, CFA; Protocatechuic acid, PCA; Syringic acid, SGA; p-hydroxyl benzoic acid, PBA; Ferulic acid, FRA and Coumaric acid, CMA) from potato peel using subcritical water.Experiments were performed in a batch stainless steel reactor at 6 MPa, 2 mL/min and temperatures ranging from 100 to 240 °C at residence time of 30 to 120 min. High recoveries of phenolic compounds (81.83 mg/100 g; wet basis wb) were obtained at 180 °C and extraction time of 30 min compared to 3 h extraction with methanol (46.59 mg/100 g wb). CGA (14.59 mg/100 g wb) and GAC (29.56 mg/100 g wb) were the main phenolic compounds obtained from potato peel at 180 °C. Subcritical water at 160 to 180 °C, 6 MPa and 60 min might be a good substitute to organic solvents such as methanol and ethanol to obtain phenolic compounds from potato peel.     

Optimization of microwave-assisted extraction of phenolics from potato and its downstream waste using orthogonal array design

While other extraction methods have been tempted, a microwave-assisted extraction (MAE) method coupled with the orthogonal array design was investigated for efficient extraction of the phenolic compounds in potato downstream wastes. Four parameters were examined for the MAE of the total phenolic content (TPC) and optimized at 60% ethanol, 80 °C, 2 min, solid-to-solvent ratio 1:40 (g/ml). The MAE was proven more efficient than the conventional solvent extraction by refluxing. The optimized model showed that the downstream wastes, both the supernatant and the residue contained high TPC, particularly the former (11.0 ± 0.26 mg GAE/g DW). The antioxidant activities (DPPH and FRAP) closely correlated with the TPC of the samples (r = 0.92–0.97). Chlorogenic acid and caffeic acid were found to be the predominant phenolic acids. The extracts of the downstream wastes from potato processing can be a promising candidate for functional foods and nutraceutical ingredients.     

Process optimisation for recovery of carotenoids from tomato waste

Carotenoids constitute an important component of waste originating from tomato processing plants. Studies were carried out to assess the extraction yield of tomato waste carotenoids in different solvents and solvent mixtures and to optimise the extraction conditions for maximum recovery. A mixture of ethyl acetate and hexane gave the highest carotenoid extraction yield among the others examined. Extraction conditions, such as percentage of hexane in the solvent mixture of ethyl acetate and hexane, ratio of solvent to waste and particle size were optimised using a statistically designed experiment. A regression equation for predicting the carotenoid yield as a function of three extraction variables was derived by statistical analysis and a model with predictive ability of 0.97 was obtained. The optimised conditions for maximum carotenoid yield (37.5 mg kg⁻¹ dry waste) were 45% hexane in solvent mixture, solvent mixture to waste ratio of 9.1:1 (v/w) and particle size 0.56 mm.     

响应面优化提取血柚皮果胶的工艺研究

采用响应面法优化了血柚皮果胶的提取工艺,在单因素实验基础上,选取柠檬酸浓度、提取温度、液料比和提取时间为自变量,果胶得率为响应值,根据Box-Behnken实验设计方法,对提取血柚皮果胶的关键因素参数进行了优化,建立了血柚皮果胶得率的数学模型。结果表明:四个因素对血柚皮果胶得率的影响大小依次为提取温度>柠檬酸浓度>液料比>提取时间;血柚皮果胶提取的最佳工艺参数为:柠檬酸浓度1.5%,提取温度82℃、液料比32∶1m L/g、提取时间99min。在此条件下,血柚皮果胶得率达18.85%,与预测值仅相差0.32%,验证了数学模型的有效性。      

Response surface optimisation for the extraction of phenolic compounds and antioxidant capacities of underutilised Mangifera pajang Kosterm. peels

The optimum extraction conditions for highest recovery of total phenolics content (TPC) and antioxidant capacities (AC) were analysed for Mangifera pajang peels (MPP), using response surface methodology. The effects of ethanol concentration (X₁: 20–80%), extraction temperature (X₂: 30–65 °C) and liquid-to-solid ratio (X₃: 20–50 mL/g) on the recovery of total phenolics (Y₁) and antioxidant capacity (Y₂) were investigated. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolic content (R² = 0.9966, p < 0.0001) and antioxidant capacity (R² = 0.9953, p < 0.0001). The optimum extraction conditions for TPC were 68%, 55 °C and 32.7 mL/g, and for AC were 68%, 56 °C and 31.8 mL/g, respectively. Predicted values for extraction of TPC and AC agreed well with the experimental values. Liquid chromatography–mass spectrometry of the optimally obtained extracts from MPP revealed the major phytochemicals as mangiferin, gallic acid, catechin and epicatechin.     

闪式提取法提取枣果皮中多酚的工艺研究

利用闪式提取法提取枣果皮中的多酚。考察了乙醇体积分数、料液比、提取时间和提取次数对枣果皮中多酚得率的影响。根据考察结果,运用正交实验方法对影响多酚得率的条件进行优化,然后进行验证实验。结果表明,最佳提取工艺条件为:乙醇体积分数为60%,料液比1∶35(g/mL),提取时间为2min,提取3次;在此条件下,多酚得率达到13.62mg/g。该工艺与超声波提取相比,简单、迅速、得率高,可用于枣果皮中多酚的提取。      

石榴皮中抗氧化物质提取条件的响应面优化

对石榴皮中抗氧化活性物质提取工艺及其成分分析进行研究,通过单因素实验和响应面优化,得到石榴皮中抗氧化物质提取工艺条件为:液固比为26mL/g、提取温度为59℃、提取时间100s、微波功率为500W,水提,此条件得到的提取物对DPPH自由基的清除率达91.067%。提取物活性成分分析表明:提取物中总多酚含量为165.67mg/g,总黄酮64.88mg/g,多糖125.04mg/g,原花青素9.16mg/g。     

超声提取柿果皮总三萜酸工艺优化

目的采用正交法优化柿果皮中总三萜酸的超声提取工艺。方法以"牛心柿"柿果皮为原料,利用紫外分光光度计法测定柿果皮中总三萜酸的含量,并从提取溶剂选择及其浓度、料液比、超声时间和温度等方面,通过单因素实验和正交试验确定超声提取柿果皮总三萜酸的最佳条件。结果最佳超声提取工艺为:在超声功率240 W的前提下,提取溶剂为75%(V/V)的乙醇、料液比1:15(m/V)、时间45 min、温度50℃。在此条件下,柿果皮总三萜得率最高可达39.33mg/g。结论优化后的方法简单、快速、准确、提取率高,适合提取柿果皮的总三萜酸。     

Enzymatic extraction of galactan-rich rhamnogalacturonan I from potato cell wall by-product

Potato cell wall was used as low-value source for the enzymatic extraction of galactan-rich rhamnogalacturonan I (RG I). The effects of selected reaction parameters of endo-polygalacturonase from Aspergillus niger-catalyzed isolation of RG I and their interactions were investigated by response surface methodology. Models were developed to relate independent parameters (cell wall concentration, enzyme amount, reaction time) to responses (yield, neutral sugar content, saccharide molar composition, weak acidic fraction proportion). The most significant parameters that affected extracted polysaccharide yield and its galactose (Gal) and arabinose (Ara) contents were the cell wall concentration and enzyme amount. The interaction between the cell wall concentration and the reaction time was the most determinant for the yield. However, the cell wall concentration and the enzyme amount exhibited significant interaction effect on Gal and Ara contents. Comparison of predicted and experimental values validated the established predicted models, which can be used to identify the conditions for the isolation of RG I-type pectic polysaccharides with selected structural and saccharide composition properties. The monosaccharide composition and the linkage patterns confirmed the isolation of galactan-rich RG I type pectic polysaccharides. The present study is expected to increase the capability to generate RG I targeting specific composition and functional properties.     

香蕉皮中果胶提取工艺的研究

采用盐析的沉淀方法对香蕉皮果胶的提取工艺进行了系统研究。通过L9(34)正交实验,得出酸解工艺的最优化条件为:以pH1.5的盐酸溶液为萃取剂、液料比5mL/g、温度95℃、时间2h、螯合剂六偏磷酸钠添加量为0.3%;盐析的最优化条件为:每100mL果胶液中加入7mLAl2(SO4)3饱和溶液,边均匀搅拌边用浓氨水调pH至4.5左右,70℃保温45min;果胶盐脱盐的条件为:每5g果胶盐置于200mL脱盐液(组成为60%乙醇 3%盐酸 37%水,V/V)中,边搅拌边脱盐30min左右,所得果胶产量0.7846g。     

Ultrasound-assisted extraction of polyphenols (flavanone glycosides) from orange (Citrus sinensis L.) peel

The present study reports on the extraction of polyphenols especially flavanones from orange (Citrus sinensis L.) peel by using ethanol as a food grade solvent. After a preliminary study showing that the best yield of extraction was reached for a particle size of 2 cm², a response surface methodology (RSM) was launched to investigate the influence of process variables on the ultrasound-assisted extraction (UAE) followed by a central composite design (CCD) approach. The statistical analysis revealed that the optimised conditions were a temperature of 40 °C, a sonication power of 150 W and a 4:1 (v/v) ethanol:water ratio. The high total phenolic content (275.8 mg of gallic acid equivalent/100 g FW), flavanone concentrations (70.3 mg of naringin and 205.2 mg of hesperidin/100 g FW) and extraction yield (10.9 %) obtained from optimised UAE proved its efficiency when compared with the conventional method. Furthermore, the antioxidant activity determined by the DPPH and ORAC tests confirmed the suitability of UAE for the preparation of antioxidant-rich plant extracts.     

基于确定性筛选设计优化柑橘皮抗氧化活性成分提取

【目的】柑橘皮抗氧化活性成分的提取工艺参数不明确,本研究采用确定性筛选设计结合设计空间法优化柑橘皮抗氧化活性成分的提取工艺。【方法】首先采用确定性筛选设计考察料液比、碱用量、醇体积分数、提取次数、提取温度和提取时间6个因素对提取效果的影响。然后,代表性抗氧化活性成分橙皮苷、芸香柚皮苷、圣草次苷的峰面积之和作为评价指标,6个因素作为变量因素,通过多元回归算法建立定量模型。基于模拟实验测定误差法计算获得关键因素与评价指标之间的设计空间。【结果】提取过程中,抗氧化活性成分的关键影响因素有3个,分别为提取次数、提取温度和料液比,并成功验证。该3个因素推荐的操作空间是提取次数为1.5~2.9,提取温度为30.2~35.0 ℃,料液比为51:1~60:1。【结论】本研究优选了提取工艺涉及的六个参数对抗氧化活性成分提取的影响,推荐的操作空间可使代表性抗氧化活性成分的峰面积达标概率达到 0. 96 以上,为工业化提取柑橘皮抗氧化活性成分提供了参考。     

多频超声波辅助提取石榴皮中原花青素的研究

介绍了从石榴皮中提取原花青素的工艺,研究了不同超声波频率、提取时间、超声波功率和提取料液比对原花青素提取率的影响.试验结果表明,最佳提取条件为:超声波频率60 kHz,提取时间65 min,超声波功率100 W,提取料液比1:10,此条件下的提取量为16.996 mg/g.     

超声波辅助提取菠萝皮多酚物质的研究

研究了超声波辅助提取菠萝多酚物质的工艺,对影响多酚浸提率的因素进行了单因素试验和正交试验,确定了最佳工艺条件为:乙醇浓度60%,浸提温度45℃,功率200W,浸提时间60min,液料比15.0∶1.0。在此条件下,浸提率可达18.48g/kg。     

加速溶剂萃取技术提取柑橘皮中总黄酮的工艺研究

应用加速溶剂萃取技术,通过单因素试验和正交试验对柑橘皮中总黄酮提取工艺进行了研究。结果表明,用加速溶剂萃取技术从柑橘皮中提取黄酮的最佳工艺条件为压力10.3MPa、乙醇浓度80%、料液比1∶15、温度70℃、浸提时间10min,此时黄酮得率为2.64%。     

从柑桔皮中超声提取橙皮苷

从柑桔皮中连续提取色素、果胶和橙皮苷。浸提果胶后的滤渣,在超声波作用下,利用饱和Ca(OH)2碱液浸提盐酸酸析得到橙皮苷。最佳工艺条件为:碱提pH12.5,液料比10:1,超声时间60min,酸析pH4.7,浸提级数3级。另外,考察了重结晶法精制对橙皮苷纯度的影响,平均纯度为94.96%,提高14.72%。红外光谱、高效液相色谱等方法表征实验产品是橙皮苷。     

微波辅助提取石榴皮多酚工艺研究

研究从石榴皮中微波辅助提取多酚的工艺.采用单因素试验及正交试验,考察不同条件下石榴皮多酚提取率.结果表明,提取溶剂乙醇体积分数、微波功率、提取时间得料液比均对石榴皮多酚提取率有显著影响;石榴皮多酚的最佳提取条件为50％(体积分数)乙醇作溶剂,微波功率300W,提取时间120s,料液比1∶35(m∶V).该条件下提取石榴皮多酚,提取率可达21.41％.     

微波辅助提取苹果皮中的多酚类物质

以苹果皮为原料提取苹果多酚,对不同提取剂的提取效果进行了比较;通过单因子试验和正交试验对微波辅助提取多酚的工艺条件进行了探讨,研究了溶剂浓度、微波功率、微波处理时间以及料液比对多酚提取的影响;并对微波辅助提取和常规法提取的效果进行了比较。结果表明：综合考虑提取效果及食品安全性,选择乙醇作为提取剂为宜;微波辅助提取的最佳工艺条件为乙醇浓度70%、微波功率210W、微波时间25s、料液比（w/v）1∶5;微波辅助提取法提取物中原花色素含量0.3668mg/ml,常规法提取物中原花色素含量0.2552mg/ml,微波辅助提取效果优于常规法提取。