共查询到20条相似文献,搜索用时 109 毫秒
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以苹果渣为原料,采用酸液提取、95%乙醇沉析的方法制取果胶,考察了酸液浓度、时间、料液比、温度等因素对果胶产量的影响,通过正交试验优化的提取工艺为:料液比1∶15(g/mL),提取温度75℃,提取时间2.0h,酸液浓度0.3%,此条件下10g干苹果渣可提取果胶为1.37g。 相似文献
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利用苹果渣提取膳食纤维的工艺研究 总被引:1,自引:0,他引:1
以苹果渣为原料,采用碱液浸提法制备水不溶性膳食纤维,考察了提取温度、时间、料液比、氢氧化钠溶液浓度等影响因素,通过正交试验优化的提取工艺为:料液比1∶10,0.5mol/L的氢氧化钠溶液,提取温度75℃,提取时间3h,此条件下膳食纤维的得率为20%。 相似文献
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本文利用碱性过氧化处理,分离提取菠萝皮渣中纤维素和半纤维素组分,得到4个不同纤维素组分(C0、C1、C2、C3)和4个半纤维素组分(H1、H2、H3、H4)。利用红外光谱、离子色谱、热重分析、差示扫描量热分析对这些组分的结构进行表征。结果表明:纤维素提取过程中,碱性过氧化处理能有效去除原料纤维中的半纤维素和木质素,离子色谱分析显示纤维素C3组分的葡萄糖含量达93%以上,较C0、C1、C2有大幅度提升,纯度显著提高;热稳性分析表明纤维素C3在335.8℃左右热解速率达到最大,在128.8℃处有一个的熔融放热峰。不同浓度碱液分步抽提半纤维样品总得率为15.61%,且4个半纤维素样品结构相似;离子色谱分析表明菠萝皮渣中的半纤维素由木糖、阿拉伯糖、半乳糖和葡萄糖组成;热稳定性分析表明半纤维H3在285.2℃时热解速率达到最大,在124.5℃处出现很强的熔融放热峰。 相似文献
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以苹果渣为原料,分别采用微波和纤维素酶作用提取可溶性膳食纤维,通过正交试验确定微波的适宜提取条件,结果表明:在料液比1:20,时间1.5min,微波火力为中火(功率450W),pH6的条件下,水溶性膳食纤维得率13.6%,持水力754.40%,溶胀性13mL/g。通过响应面优化试验确定纤维素酶适宜的提取条件是:纤维素酶用量0.67%,缓冲液pH5.55,酶解时间1.90h,酶解温度45℃。此时,水溶性膳食纤维提取率17.50%,持水力851.25%,溶胀性15mL/g。 相似文献
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杨梅渣黄酮类化合物提取及其抗氧化活性研究 总被引:1,自引:1,他引:1
杨梅是我国的特产水果,年产量约为100万t,其中杨梅渣约占果实总重的10%。目前以杨梅为资源的食品工业已初具规模,然而在杨梅深加工过程中,杨梅渣都作为废物进行处理,对其开发利用仍然一片空白。基于此,以杨梅渣为研究对象,对杨梅渣中黄酮类化合物进行提取、浓缩、萃取,分成四个级分(石油醚相、乙酸乙酯相、正丁醇相和水相);用DPPH法、Fenton反应法和还原能力评价了四个不同级分的杨梅渣提取物的体外抗氧化能力。结果表明,杨梅渣粗提物正丁醇相和乙酸乙酯相具有较强的清除DPPH自由基能力,其半抑制浓度(IC50)分别为30、40μg/mL,分别是维生素C(IC50=110μg/mL)的3.67、2.75倍。 相似文献
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主要研究了库尔勒香梨在不同条件下贮藏时,其形成锈斑过程中果实木质素和纤维素含量的变化。采用质量法测定香梨果实木质素和纤维素的含量。结果表明,在冷藏条件下,较高的温度和湿度有助于锈斑的形成,且木质素和纤维素含量较高;相同湿度下,高浓度CO2可能对果实造成伤害,使果实品质下降较快,造成木质素和纤维素含量增加;锈斑区域木质素和纤维素含量比完好组织高,且随着锈斑继续增大,锈斑区域木质素和纤维素积累越多,其与完好组织之间木质素和纤维素含量差异越明显。 相似文献
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Carla Da Porto & Susi Soldera 《International Journal of Food Science & Technology》2008,43(3):495-500
Fermented marc was exposed to a controlled smoking process for 120, 240 and 460 min before distillation. To improve insight into the behaviour of ethanol and the partitioning of some volatile compounds, each distillate was collected in fractions (ethanol content from 24 to 59% vol) and analysed for the higher alcohols (2‐butanol, n‐butanol, n‐propanol, isoamyl alcohols, n‐hexanol) ethyl esters (ethyl acetate, ethyl lactate, ethyl caproate, ethyl caprylate, ethyl caprate, ethyl myristate and ethyl laurate) and volatile phenols (guaiacol, methyl guaiacol, ethyl guaiacol, propyl guaiacol, eugenol and isoeugenol). The results obtained showed that the behaviour of ethanol was not regular and the alcohol strength was lower when the smoking process was applied to fermented marc. The volatile phenols highlighted a distillation behaviour characterised by an increase in concentration at the end of the distillation process when ethanol decreased. Long time exposure of the marc to the smoking process resulted in higher reduction of ethanol, higher alcohols and ethyl esters. Instead, the volatile phenols increased with the duration of the smoking process. 相似文献
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苹果果胶酯酶提取及其酶学性质探究 总被引:1,自引:0,他引:1
以国光苹果为原料,通过单因素和正交实验考察了Na Cl浓度、p H、提取温度和提取时间对苹果果胶酯酶酶活的影响,确定了苹果果胶酯酶最佳提取工艺参数,并研究了苹果果胶酯酶的酶学性质。结果表明:在Na Cl浓度为2.5mol/L、p H为8.5、提取温度30℃和提取时间为27h时,苹果果胶酯酶的酶活达到0.98μmol/min·m L;该酶反应的最适温度为40℃,热稳定性较差,最适p H为11;金属离子中Ca2+对果胶酯酶有显著的激活作用,Na+、K+和Fe2+也有一定的激活作用,而Ba2+、Mn2+和EDTA对果胶酯酶有抑制作用。 相似文献
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Katalin Sólyom Stefan Kraus Rafael B. Mato Volker Gaukel Heike P. Schuchmann María José Cocero 《Journal of food engineering》2013
Microwave assisted extraction enhances antioxidant extraction kinetics in grape marc processing. For an effective microwave process design, the dielectric properties (DPs) of the material must be known under different conditions. This study focused on the DP measurement of grape marc using a resonant cavity measuring device. Grape skin, seeds and their mixtures with three different moisture contents were studied at 28, 39 and 50 °C. At higher moisture content DP showed increasing tendency, while temperature didn’t have a definite effect. Good correlation was achieved with the experimental results applying the complex refractive index mixing equation between 0.4 and 0.6 porosity. Also, despite the complexity of natural products properties, the experimental DP values of the real mixture were in agreement with values estimated from DP properties of its individual constituents (grape skin and seeds). Milling was performed to obtain homogeneous material for the measurements, and this effect on the results was also studied. 相似文献