柚子果醋加工工艺初探

以新鲜柚子为原料,通过预处理、榨汁、酒精发酵、醋酸发酵等生产工艺发酵制成柚子果醋。对其生产工艺进行了探讨,经3天酒精发酵和6天醋酸发酵,结果表明:制得的果醋总酸度为7.23%,糖度为9%,风味纯正,并带有柚子的香气,而且各项微生物指标均符合国家标准。     

Variation in Furanocoumarin Content and New Furanocoumarin Dimers in Commercial Grapefruit (Citrus paradisi Macf.) Juices

ABSTRACT: Grapefruit ( Citrus paradisi Macf.) sales and crop value have declined during the last decade. One reason is consumer concerns about possible drug interactions. Coadministered grapefruit increases the bioavailability of some medicines because it contains furanocoumarins that inhibit an intestinal enzyme (cytochrome P450-3A4 or CYP3A4) that normally metabolizes these drugs. Only drugs metabolized by intestinal CYP3A4 are significantly affected when taken with grapefruit juice, but the magnitude of the effect varies considerably between studies, indicating that there are differences in the amount of components responsible for CYP3A4 inhibition in commercial grapefruit juices. Content variation of 6,7-dihydroxybergamottin, bergamottin, and 6 furanocoumarin dimers were determined for 58 commercial grapefruit juices collected over 2 seasons. The content of 6,7-dihydroxybergamottin ranged from 0.2 to 7.7 ppm in all juices tested, and averaged 1.8 ± 0.85 ppm in the red compared with 2.9 ± 2.07 ppm for white grapefruit juices. Bergamottin content ranged from 1.6 to 7.3 ppm for all juices and averaged 3.4 ± 0.98 and 4.2 ± 1.23 ppm and in red and white grapefruit juices, respectively. Only 1 dimer varied significantly between the red and white juice types. Dihydroxybergamottin and 2 dimer compounds were significantly lower in shelf-stable or nonrefrigerated products compared with refrigerated products whereas bergamottin and 1 dimer compound occurred at higher levels in the shelf-stable products. Individual measured dimer compounds varied up to 60-fold in all juices, but the sum of all 6 dimers varied only 14-fold. The clinical significance in terms of CYP3A4 inhibition is uncertain. The presence of 3 new furanocoumarin dimers are also reported.     

Recovery of Grapefruit Oil Constituents from Processing Waste Water using Styrene-divinylbenzene Resins

Styrene-divinylbenzene (SDVB) resins were utilized for the recovery of coldpressed grapefruit oil constituents from model solutions and waste waters. Sorption rates and sorption capacities were determined for a series of resins with model solutions. Citrus oil processing waste water was passed through an upflow column extraction system. Adsorbed oil was desorbed using 95% ethanol and gas chromatographic analysis was performed to determine the quality of the extracted oil. The waste water samples contained suspended solids which reduced the extraction ability of the resins. Major compounds recovered from waste waters were d-limonene and alpha-terpineol. Nootkatone and linalool recovery levels varied, while octanal and decanal were present in extremely low levels in the recovered products.     

Influence of harvest time on citrus pectin and its in vitro inhibition of fibroblast growth factor signal transduction

Seasonal changes in pectin content and chemical composition were studied in three anatomical layers of ‘Rio Red’ grapefruit (Citrus paradisi Macf), a currently popular cultivar in the Rio Grande Valley in Texas, USA. Fruits were harvested at intervals between August 1998 and May 1999. Pectin content in flavedo decreased throughout the season, while in albedo and segment membrane the pectin content was lowest in mid‐season (November and January). In all three layers the anhydrogalacturonic acid (AGA) content of pectin was highest in mid‐season. While the methoxyl content (MC) of pectin increased, the total neutral sugar (TNS) content of pectin decreased in all three layers throughout the season. The in vitro effect of grapefruit pectin on fibroblast growth factor (FGF)–FGF receptor (FGFR) interaction was also investigated. The strong interdependence of heparin on factor–receptor interaction provides means for identifying new antagonists of growth factor activity and thus for treatment of various diseases. Our results showed that grapefruit pectin significantly inhibited the binding of FGF‐1 to FGFR1 in the presence of 0.1 µg ml^?1 heparin. Pectin of albedo from grapefruits harvested in January was the most potent inhibitor. The in vitro inhibitory activity was significantly correlated with the percentage of rhamnose. Kinetic studies revealed a competitive nature of pectin on FGF signal transduction with heparin. The observation that the biological activity of heparin can be antagonised by citrus pectin suggests that pectins should be investigated further as anti‐growth factor agents for potential health benefits. © 2002 Society of Chemical Industry     

香梨酒酿制过程的若干问题探讨

分析了库尔勒香梨酿制发酵酒的意义,同时论述了香梨酒的生产工艺及酿制过程中的关键技术问题。     

库尔勒香梨白兰地酿造工艺初步研究(一)

研究了在香梨白兰地发酵中采取不同性状的香梨原料及破碎方式、不同调糖浓度及调SO2 浓度、在不同的调酸时间和温度等各发酵条件对香梨白兰地风味的影响 ,并依此酿造工艺 ,对所用酿酒干酵母与自选酵母进行了扩大发酵比较。     

柚皮粉对水中Pb(Ⅱ)的吸附性能研究

用柚皮粉进行了吸附去除水中Pb(Ⅱ)的模拟实验研究.考察了pH、吸附时间、柚皮粉质量浓度和Pb(Ⅱ)初始质量浓度等因素对吸附效果的影响,探究了其吸附动力学及吸附规律.结果表明,pH、吸附时间、柚皮粉质量浓度和Pb(Ⅱ)初始质量浓度、温度等因素对柚皮粉吸附水中Pb(Ⅱ)有显著影响.适宜的吸附条件为:pH 5.3 ～6.0...     

基于SBSE-GC/MS的荔枝白兰地香气成分分析

应用搅拌棒萃取法提取荔枝白兰地中的的香气物质,用峰面积归一法进行定量分析,结合气相色谱-质谱技术及计算机检索技术对分离化合物进行鉴定。荔枝白兰地中香气物质经气相色谱分离共得到65个峰,鉴定出61种物质,占总峰面积的95.81%,对荔枝白兰地香气贡献较大的是酯类60.77%、酸类12.23%、醇类7.62%、苯环衍生物6.13%、酮类化合物4.90%和萜烯类化合物4.53%,香气成分含量较高的前十种物质依次是乙酸乙酯19.02%、2,4-己二烯酸乙酯16.53%、山梨酸10.73%、琥珀酸二乙酯7.70%、辛酸乙酯4.73%、正戊醇4.60%、2,6-二叔丁基对苯甲酚2.25%、苯乙醇2.16%、玫瑰醚2.06%、己酸乙酯1.96%。构成荔枝白兰地香气特征的物质主要是酯类、醇类、酸类、少量的酚类及萜烯类化合物。     

Grape brandy production,composition and sensory evaluation

Grape brandy is a spirit drink produced by wine distillation and is matured in wooden casks. According to legislation, it can be characterised by the geographical area where the grapes were produced, the grape variety used and the selected distillation and ageing techniques. Distillation increases ethanol concentration and aromatic constituents which are already present in grapes or are developed during fermentation and distillation. During maturation in wooden casks, compounds that contribute to the aroma and taste are extracted from the wood. Hence the spirit acquires the desired softer mouth feel, aromatic complexity and overall quality. Different methods of analysis are used in order to pursuit this process by analysing volatile and non‐volatile substances and correlate composition with quality. Analysis can also be useful in identification of brandy safety, potential adulterations, provenance and differentiation from other spirits drinks. © 2013 Society of Chemical Industry     

Evaluation of Ultrafiltration and Adsorption to Debitter Grapefruit Juice and Grapefruit Pulp Wash

Grapefruit juice and grapefruit pulp wash were ultrafiltered and debittered with a pilot system. The flow rate through the membrane increased with the transmembrane pressure up to 137.8 kPa. Limonin in grapefruit juice and grapefruit pulp wash was completely removed. The debittering process was tested at 13, 27 and 48°C. Limonin removal efficiency was independent of temperature between 13 and 48°C. However the resin column was exhausted more rapidly for na-ringin, narirutin, hesperidin, and neohesperidin particularly at 13°C. Taste panel results suggested that debittering of grapefruit pulp wash appreciably increased its flavor acceptability.