Dietary Fiber Binding of Bile Acid through Mineral Supplementation

Iron and/or calcium were added to psyllium, guar gum, locust bean gum, citrus rag, high methoxy pectin, and low methoxy pectin. This mixture was then incubated with either cholic acid, deoxycholic acid, glycocholic acid, or taurocholic acid to evaluate the effect of minerals on fiber-bile acid binding. The addition of iron with or without calcium increased the binding of deoxycholic acid to all fibers (p≤0.01 and p≤0.025) except low methoxy pectin. Iron and calcium caused increased binding of high methoxy pectin to all bile acids (p≤0.01 and p≤0.025). Dietary fiber's ability to bind certain bile acids may be maximized through mineral supplementation.     

液相色谱法测定葡萄及柑橘中二氰蒽醌的残留量

建立了液相色谱快速测定葡萄及柑橘中二氰蒽醌残留量的方法。样品经乙腈和盐酸水溶液提取,NaCl盐析,直接液相色谱检测。与现有方法相比,本方法前处理简单、快速、溶剂消耗量少。二氰蒽醌在0.6,3.0 mg/kg 2个添加水平下,平均回收率为91.5%~107.1%,相对标准偏差为1.3%~2.4%,方法的最低检测浓度为0.1 mg/kg。     

Postharvest Gibberellin and Heat Treatment Effects on Polyamines, Abscisic Acid and Firmness in Lemons

Lemons at two ripening stages were vacuum-infiltrated with 100 ppm of gibberellin A₃ (GA₃) or heat-treated at 45°C, and then stored at 15°C for 3 wk. Both treatments increased fruit firmness either in stage 1 or in stage 2. Also, the levels of free putrescine and spermidine in the skin were higher in treated lemons than in controls but spermine concentration did not show significant differences, in fruits of either stage. GA₃ treatment was the most effective in retarding the color change during storage, especially in stage 1 fruits, which was related to the lowest levels of abscisic acid found.     

Limonoids in Pummelos [Citrus grandis (L.) Osbeck]

Juice and seeds from 16 cultivars of mature pummelo fruits were analyzed for limonoid content. Pummelo juice contained an average of 18 ppm limonin and 29 ppm total limonoid glucosides. Compared to other juices, ptmnnelo contained very high concentrations of limonin and very low concentrations of limonoid glucosides. Limonin, nomilin, obacunone and trace amounts of deacetyhromilin were found in pummelo seeds. The 17–β-D-glucopyranoside derivatives (glucosides) of nomilin, nomilinic acid and obacunone were also present. Total limonoid aglycone concentration in the seeds ranged from 773 ppm to 9,900 ppm and total limonoid glucosides ranged from 130 ppm to 1,912 ppm.     

水土流失区低产柑桔园改造若干技术问题

通过病虫害防治、施肥方法的改进、保花保果合理修剪、科学灌水措施的实施，使水土流失区的低产柑桔园连续９年增产、稳产、平均年产量达１１．４ｔ，平均株产量为２８ｋｇ．     

近红外光谱检测柑橘糖度光照角度可调装置设计与试验

目的:解决近红外光谱检测水果糖度固定光照角度获得光谱信息不够全面等问题。方法:基于光源远程运动中心简化模型,设计了一种漫透射近红外光谱检测柑橘糖度的光照角度可调装置,并对该装置进行了结构性能分析,开展了不同光照角度的柑橘糖度光谱检测试验。结果:该装置光照角度的调节范围可设置为0°～60°;60°时4个光源光斑中心与靶心位移偏差最小为7.5 mm;不同光照角度下2、3、4号光源光照角度平均值与1号光源基准值的误差在1°以下;光照角度30°时,原始透射率光谱数据所建的柑橘糖度预测模型效果最佳,预测集、校正集的相关系数和均方根误差分别为0.887 6,0.897 5和0.456 0,0.430 9°Brix。结论:所研制的近红外光谱检测装置能够实现自动同步调节4个光源对准水果中心的光照角度。     

D-101大孔吸附树脂分离纯化橘皮中的黄酮类物质

目的:研究D-101大孔吸附树脂分离纯化橘皮黄酮类物质的工艺条件。方法:采用静态和动态吸附-解吸附两种方法,以黄酮类物质吸附率和解吸附率为评价指标,考察橘皮提取液pH值、吸附液料比、静置吸附时间、洗脱液种类和洗脱液料比等影响因素。结果:D-101大孔吸附树脂分离纯化橘皮黄酮类物质的最佳工艺条件为提取液pH4.43,吸附液料比15:1(黄酮类物质溶液:大孔吸附树脂,mL/g)、静置吸附时间90min、洗脱液为95%乙醇溶液、洗脱液料比25:1(95%乙醇溶液:大孔吸附树脂,mL/g)。结论:该方法简单、可行,能够用来分离纯化橘皮中黄酮类物质。     

Identification, Synthesis, and Field Testing of the Sex Pheromone of the Citrus Leafminer, Phyllocnistis citrella

The citrus leafminer is an important vector of citrus canker in many of the major citrus production areas of the world. (7Z,11Z)-Hexadecadienal was reported as a sex attractant for this insect in the 1980s, based on trap catches during pheromone screening trials in Japan. However, attempts to reproduce this work in other areas of the world have not been successful. We report here that (7Z,11Z)-hexadecadienal is only one component of the pheromone, with the other critical component being the analogous trienal, (7Z,11Z,13E)-hexadecatrienal. Both compounds were identified in the effluvia from live female moths by coupled gas chromatography (GC)-electroantennography using nonpolar and polar GC columns, and the identifications were confirmed by comparisons of mass spectra with those of authentic standards. Stereoisomers of the two compounds, and a number of analogs, were synthesized to confirm the identifications. In field trials, neither compound alone was attractive to male moths, but blends of the two were highly attractive, with thousands of insects being caught per trial. Addition of the isomeric (7Z,11Z,13Z)-hexadecatrienal inhibited attraction to the two-component blend. Electronic Supplementary Material Supplementary material is available for this article at and accessible for authorized users. This paper and the preceding paper (Leal et al.) were submitted within a few days of each other. The editors and the authors agreed that they should be published in tandem.     

Physicochemical properties of pectins from ambarella peels (Spondias cytherea) obtained using different extraction conditions

Extraction and use of pectins from ambarella peels could add value to the waste products arising from processing of the fruit. Dried alcohol-insoluble residues (AIR) of ambarella peels were treated separately with HCl, deionised water and oxalic acid/ammonium oxalate solutions, and the resulting pectin extracts analysed for some biochemical and physicochemical parameters. The results show that pectin yield (9–30% dry AIR), uronic acid (557–727 mg/g dry weight), neutral sugars (125–158 mg/g), degree of methylation (50–58%) and acetylation (4–6%), molar mass (263,000–303,000 g/mol) and intrinsic viscosity (179–480 ml/g) varied significantly (p < 0.05) with the various extraction methods used. Extraction with oxalic acid/ammonium oxalate solution gave the highest pectin yield, with high molar mass and degree of methylation, making the extracts suitable for use as additives in the food industry. The results compared well to lime pectin extracted under the same conditions, indicating their commercial significance.