Multiple Forms of Pectinmethylesterase from Citrus Peel and Their Effects on Juice Cloud Stability

Heparin chromatography of a dialysis supernatant fraction from total salt extractable proteins of Citrus sinensis (L.) Osb. var. Valencia fruit peel (flavedo plus albedo) resolved four peaks of pectinmethylesterase activity (PME 1–4). One of these was thermally tolerant (PME 3). Binding to concanavalin A suggested PME 3 was a glycoprotein. At 30°C and 5 U - mL1 PME 1, 2 and 3 destabilized the cloud of pasteurized FCOJ within 10 days. PME 1 caused the most rapid cloud loss (3d), followed by PME 3 and PME 2. PME 4 had no effect on juice cloud during this time period. At 4°C PME 3 caused the most rapid cloud loss (3d), followed by PME 1 (14d) and PME 2 (>14d). PME 4 had no effect on juice cloud stability after 10 days at 30°C or 14 days at 4°C.     

柑橘皮渣膳食纤维的特性及其在食品中的应用

膳食纤维是人类的第七种营养素,具有预防肥胖,调节肠道菌群等生理活性.柑橘皮渣是膳食纤维的良好来源之一,目前国内对于柑橘皮渣膳食纤维的研究主要集中在制备工艺,但对柑橘皮渣膳食纤维在食品中的工业化应用研究还比较薄弱.因此,开发和利用柑橘皮渣膳食纤维已成为当前研究的热点.由于柑橘皮渣膳食纤维具有优异的理化性质,能够作为一...     

漂烫对宽皮橘去皮性能及橘皮微观结构影响的研究

以宽皮柑橘为原料,漂烫不同的温度和时间,以柑橘整果刺穿力和橘皮拉伸性能等力学性质,橘皮蜡质、白皮层的微观结构等研究漂烫对柑橘去皮性能的影响;以去皮柑橘感官评价(果香、口感及白皮覆盖率)和理化性质(固形物含量、还原糖含量、可滴定酸含量及Vc含量)为评价指标定量柑橘最佳漂烫方式。结果表明,不同的漂烫条件导致橘皮力学性质不同,适当的漂烫能降低柑橘整果的刺穿力,增强橘皮抗拉强度,这是通过改变柑橘外果皮蜡质层的组织形态和白皮层中纤维素-果胶的经纬结构实现的。85℃下漂烫70 s柑橘整果刺穿力较小(8.68±0.04 N),但橘皮抗拉强度增加(0.18±0.05 MPa),且柑橘果香和口感增强,去皮后白皮覆盖率显著降低,从而增强了去皮效果。因此,漂烫能通过影响橘皮力学性质和微观结构增强去皮性能。     

柑桔类果汁的脱苦技术

本文简要介绍了脱除柑桔类果汁苦味的一些技术,这些技术包括:代谢脱苦法、屏蔽脱苦法、吸附脱苦法、酶法脱苦、固定化细胞脱苦、超临界CO2脱苦、超临界CO2脱苦法、膜技术脱苦、基因工程脱苦。     

超声波辅助提取柑橘皮橙皮苷研究

以柑橘皮为原料,碱性复合磷酸盐水溶液为提取溶剂,采用超声波辅助提取柑橘皮中的橙皮苷。以橙皮苷提取率为考察指标,考察了液料比、提取温度、超声功率和提取时间对橙皮苷提取率的影响。通过正交试验得到了超声波辅助提取柑橘皮中橙皮苷的合理工艺:液料比为30 m L/g、提取温度为60℃、超声功率为240 W、超声处理时间为30 min。在此工艺下,橙皮苷提取率高、试验重现性好。     

胡萝卜橙汁复合饮料研制

研究胡萝卜橙汁复合饮料的稳定性及配方.结果显示:理想的配方为2.5%的胡萝卜浓缩汁加果萄糖12%、柠檬酸0.20%、浓缩柳橙汁0.4%、浓缩苹果汁0.1%.以果胶AMD和黄原胶为复合稳定剂效果较好.     

温州蜜柑复合柑橘汁开发及品质研究

为改善尾张、宫川两个主栽温州蜜柑品种制汁后口感欠佳和风味不足的问题,分别以两种温州蜜柑汁为基料,添加冰糖橙汁或纽荷尔脐橙汁进行复配,开发温州蜜柑复合柑橘汁.采用常规方法测定不同复配比例的柑橘汁中总酚、黄酮、可溶性糖、VC、可滴定酸、pH、可溶性固形物、悬浮稳定性及挥发性风味成分,采用感官评价和主成分分析法优选口感和风味...     

Extraction Methods of Citrus Peel Phenolic Compounds

Several extraction methods have been reported in the literature for the extraction of phenols from citrus peel. Extraction methods may cause a degradation of phenolic compounds due to high applied temperature and pressure or long extraction times (conventional solvent extraction, high-pressure extraction). However, other extraction methods are limited by the polarity of phenolic compounds (supercritical CO₂ extraction). Novel techniques of extraction of bioactive compounds have been developed in order to shorten the extraction time, increase the extraction yield, and prevent the degradation of the phenolic compounds. This review provides a critical comparison of the different extraction methods of citrus peel phenolic compounds. The review compiles valuable data that could be useful for the choice of an appropriate extraction method for bioactive compounds from vegetables sources. The main parameters influencing the extraction yield are also discussed.     

柑桔皮中非水溶性膳食纤维的提取及特性研究

本研究将乙醇脱色法和中性洗涤法结合提取柑橘皮中的非水溶性膳食纤维,其最佳提取工艺为：料水比1:30,提取温度70℃,提取时间90min。结果表明：持水性、膨胀性随温度增加而增加,随着氯化钠溶液、葡萄糖溶液浓度的增加而降低。在中性条件下有一定的持水力和膨胀性;偏酸或偏碱条件能促进其持水性和膨胀性的增加,但在过酸或过碱条件下,其持水性和膨胀性均呈现下降趋势。     

柑桔汁脱苦降酸方法研究进展

全食概念日渐为消费者青睐的情况下,柑桔全果制汁是柑桔精深加工的重要方向之一,有效的脱苦降酸工艺对促进柑桔汁生产有重要意义。本文对柑桔汁脱苦的9种方法及降酸的6种方法进行了综述。     

超声波辅助提取橘皮中黄酮类化合物

研究利用超声波辅助提取橘皮黄酮类化合物的工艺条件,并探讨超声波频率、溶剂浓度、提取时间、提取温度和料液比对提取效果的影响。研究确定影响黄酮提取效果的最主要因素是料液比,并得出橘皮黄酮提取的最佳工艺条件为超声波频率为低频(25.5 kHz),提取溶剂为60%乙醇,提取时间40 min,提取温度75℃,料液比1∶10(g/mL)。     

新型搅拌型柑橘酸奶的研制

以鲜牛乳为主要原料,适当添加柑橘汁、砂糖及柑橘果粒等混合调配,经混合乳酸菌发酵制备新型搅拌型柑橘酸奶,应用正交试验设计筛选出该酸奶的工艺及配方。实验结果表明:以新鲜优质牛奶为原料,加入12%的柑橘汁、9%的砂糖、4%的乳酸菌,经4 h发酵即可制作出品质优良、各项指标符合国家标准的柑橘酸奶;实验还比较了两种脱苦剂对柑橘果汁的脱苦效果,结果表明β-环状糊精的脱苦效果优于活性炭;采用打蛋器搅拌破乳能提高产品的品质。     

Citrus Tissue Extracts Affect Juice Cloud Stability

Salt extractable proteins were isolated from hand expressed juice, rag and peel of Valencia oranges. Each tissue extract was divided into dialysis supernatant (DS) and precipitate (DP) (forms during dialysis). DP, DS and DS heated for 2 min at 80°C (HDS) were added to pasteurized, reconstituted frozen concentrated orange juice at 5 U · mL^?1 of pectinmethylesterase. Samples were incubated either at 25°C for 14 days or 4°C for 28 days and periodically sampled to determine the effects of tissue extracts on juice cloud stability. Tissue specific differences were observed for the rate of juice cloud precipitation and among the HDS, DS, and DP fractions of a given tissue. HDS fractions destabilized juice cloud more rapidly than DS or DP at both 25 and 4°C.     

比色法测定柑桔饮料及桔皮制剂中总黄酮含量

本文介绍了比色法测定柑桔饮料及桔皮制剂中总黄酮的方法。样品经稀碱浸提，总黄酮与碱性二甘醇反应呈色，在４２０ｎｍ波长下测定吸光度，用扣除本底的方法消除干扰，以橙皮苷为标准计算含量。该方法最低检出浓度为１．１ｍｇ／１００ｇ，相对标准偏差为１．１９～４．９３％，平均回收率为１００．２±３．１％，测定结果与其它方法无显著性差异。     

微波辐射法提取柚皮、橙皮挥发油的研究

采用微波辐射法提取橙皮、柚皮的挥发油。结果表明最佳的萃取条件为：100g果皮在360w下，用300ml正己烷萃取50s，柚皮油得率为1．73％，橙皮油得率为0．65％。     

潮州柑果皮色素的提取及稳定性研究

本实验对潮州柑果皮色素的提取条件及其稳定性进行了研究,旨在为潮州柑的综合开发利用提供依据。研究结论表明:潮州柑果皮色素亮黄色,颜色鲜艳,色素最佳提取溶剂为70%乙醇,最佳提取温度50℃,最佳料液比1:30,最佳提取时间360min。该色素对光、热、酸碱(pH3～11)、氧化剂和还原剂、常用食品添加剂及金属离子都比较稳定,是一种稳定性良好、安全可靠、价廉易得、开发方便的天然植物色素。     

柚皮中有效成分综合利用的途径

柚皮含有丰富柚皮苷、类胡萝卜素、果胶和香精油等,具有较高的保健和药用价值,进行柚皮资源的综合利用具有良好的社会效益和经济效益。本文对柚皮中香精油、黄酮类化合物、色素和果胶的作用、应用和提取方法等方面进行了介绍。     

Reverse Osmosis Concentration of Aqueous-Phase Citrus Juice Essence

Dilute aqueous essences of 2 to 20% ethanol obtained from commercial orange juice evaporators when concentrated to 31% ethanol by reverse osmosis resulted in increased concentration of the small aroma molecules and acetaldehyde. Rejection of ethanol varied from 90% at 2% ethanol to 40% at the highest concentration achieved (31%). Acetaldehyde rejection varied from about 65% at 2% ethanol, to an extrapolated low value of 25% at 31% ethanol. Rejection was generally greater than 85% for larger aroma molecules, e.g., ethyl butyrate, hexanal and terpenes. Permeate flux rates followed a first order decay with increasing ethanol concentration, from greater than 300 at 0.01% ethanol to 26 L/H/module at 31% ethanol, 8.3 MPa, 30°C.     

β-葡萄糖苷酶对胡柚汁脱苦效果的研究

胡柚汁营养丰富,但也有柠檬苦素、柚皮苷等苦味物质。由于这些苦味物质的存在,限制了胡柚的深加工和消费者的需求。本实验利用β-葡萄糖苷酶对胡柚果汁进行了脱苦研究。结果表明,在50℃下pH5的胡柚汁中添加200U/Lβ-葡萄糖苷酶作用60min,对胡柚果汁脱苦效果良好,而对VC等营养成分的损失不明显。     

柑橘类果汁货架期研究进展

柑橘类果汁货架期是衡量柑橘类果汁质量稳定性的一个重要指标。文中从柑橘类果汁的包装材料、加工工艺、流通环境等方面系统介绍和分析柑橘类果汁货架期的研究进展,并概括柑橘类果汁的质量损失方程及货架期预测模型。最后分析目前研究存在的不足,为今后柑橘类果汁货架期研究提供参考。