超声波和微波对柑橘杂交种果皮中酚类物质浸提及其抗氧化能力的影响

以柑橘杂交品种葡萄柚、茂谷橘橙果皮为材料,研究超声波和微波对柑橘果皮提取物中酚类物质及其抗氧化活性的影响。结果表明:葡萄柚果皮中含有丰富的柚皮苷、芦丁、橙皮素等酚类物质,茂谷橘橙果皮中含有丰富的槲皮素、川陈皮素、橙皮素等酚类物质。葡萄柚果皮提取液的抗氧化活性高于茂谷橘橙。葡萄柚果皮超声波提取液中酚类物质的含量和抗氧化活性高于微波提取液。柑橘果皮提取物中酚类物质的含量与其DPPH自由基和羟自由基清除能力呈正相关。此结果说明超声波提取法可提高葡萄柚果皮中酚类物质的提取率和提取液抗氧化能力。     

基于牛粪垫料的有机无机复混肥对橘柚产量和品质的影响

为验证橘柚生长期追肥配施有机肥的可行性,根据橘柚膨果期需肥特性调配2种有机无机复混肥,采用大田实验,并设置多个施肥量,探讨有机无机复混肥用作追肥时不同施肥量对橘柚产量和品质的影响。结果表明,配方1和配方2均对橘柚产量无显著影响,显著降低了单果重、果皮重和果皮厚度,但增加了果肉比例,其中配方1施肥量为6.0 kg/株时果肉比例最高,达68.18%。配方1的5个施肥量均显著降低了橘柚果实总可溶性酸含量,显著增加了总可溶性糖、还原糖及抗坏血酸含量,提高糖酸比。而配方2的5个施肥量显著提高了橘柚的糖酸比,部分施肥量增加了总糖和还原糖含量。其中配方1施肥量与总糖和还原糖含量的关系可用三次回归方程和幂函数方程拟合。综上所述,橘柚生长期施用有机无机复混肥是可行的,其中配方1的肥效优于配方2,配方1推荐施肥量为4.8~6.0 kg/株为佳,而配方2推荐施肥量为3.6~4.5 kg/株为佳。     

不同品种荔枝果皮酚类物质组成及其抗氧化活性比较

为比较不同品种荔枝果皮酚类物质含量、组成及其抗氧化活性差异,用80%甲醇分别提取6个品种荔枝果皮中的酚类物质,测定其总酚和总黄酮含量。采用铁离子还原能力（FRAP）和自由基离子清除能力（ABTS）等方法评价其抗氧化活性。通过高效液相色谱（HPLC）鉴定不同的单体酚并分析其在不同品种荔枝果皮之间的差异。结果表明,不同品种荔枝果皮的酚类物质含量为28.69~68.48 mg/g,不同品种荔枝果皮的酚类物质含量和抗氧化能力存在显著的差异（P<0.05）。酚类物质的含量、FRAP和ABTS抗氧化活性能力均以‘荔枝王’为最高,分别为68.48 mg/g_、546.31 μmol/g和511.25 μmol/g。液相色谱结果鉴定出‘糯米糍’中的8种单体酚,而含量相对较高的是A型原花青素三聚体和原花青素A2。研究结果可为荔枝加工废弃物荔枝果皮的开发利用提供理论依据。     

响应面法优化葡萄柚果皮柚皮苷微波提取工艺

为充分利用废弃物葡萄柚果皮,进一步提高葡萄柚果皮中柚皮苷的提取效率,采用响应面分析法对葡萄柚柚皮苷微波辅助提取工艺中的乙醇体积分数、液料比、微波时间3因子的最优化组合进行定量研究,建立并分析各因素与柚皮苷得率关系的数学模型。结果表明:最佳工艺条件为:乙醇体积分数80%,液料比70∶1(mL/g),提取时间50 s,重复提取3次。在此条件下,以柚皮苷得率为模型预测可获得柚皮苷得率为57.35 mg/g,与理论值57.75 mg/g基本一致。说明数学模型能较好的预测葡萄柚果皮中柚皮苷的提取率。     

基于PCA分析‘南丰’和‘新余’蜜橘的耐贮性差异

品种的差异是影响采后柑橘果实耐贮性的重要因素之一。采用主成分分析法对江西省2个主栽宽皮柑橘品种‘南丰’和‘新余’蜜橘果实在低温(5 ± 0.5) ℃下贮藏过程中,果实腐烂率、失重率、果皮色差指数、褐变指数、可滴定酸、维生素C、可溶性固形物、总糖、呼吸强度、相对电导率、抗氧化酶活性等14个生理指标的变化进行统计分析,筛选出代表果实耐贮性能指标88.781%信息量的3个主成分,第1主成分反映失重率、果皮色差指数、褐变指数、可滴定酸、呼吸强度、相对电导率、过氧化氢酶活性、多酚氧化酶活性8个生理指标的信息;第2主成分反映腐烂率、可溶性固形物、总糖、超氧化物歧化酶和过氧化物酶的信息;第3主成分反映维生素C的信息。主成分分析法能科学评价‘南丰’和‘新余’蜜橘果实的耐贮性差异,综合单一指标和主成分分析结果表明,‘南丰’蜜橘果实的耐贮性优于‘新余’蜜橘。     

化州橘红茎尖微芽嫁接技术研究

以柚、柠檬、红江橙等作砧木,化州橘红作接穗.研究了激素处理砧木、接穗灭菌和培养基配方、砧木苗龄等因素对化州橘红茎尖嫁接成活率的影响.柚作砧木时,任何激素处理的成活率均高于对照,以0.1 mg/L的GA3处理10 min的成活率最高,为31％.不同砧木其成活率不同,成活率最高的为柚,达19.0％,最低的为宽皮橘,为5.0％.灭菌方法对成活率和污染率也有影响,污染率最低的是0.1％升汞灭菌10 min,为5.7％,成活率最高的是0.15％升汞灭菌8 min,为25.0％.培养基配方对嫁接苗的成活率也有影响,MS基本培养基最有利于嫁接苗的成活,添加6-BA、Ad和NAA都会降低成活率.16d苗龄的砧木最有利于嫁接苗的成活,成活率可达36.5％.     

广陈皮原料茶枝柑与其他典型柑橘成分差异分析

本文以广陈皮原料茶枝柑为对照,探究了其他典型的柑橘原料在可溶性糖、可溶性蛋白质、总黄酮、总多酚等方面的差异,分析其他橘皮作为茶枝柑替代品的可行性。结果表明,温州蜜柑、脐橙、湖北柑果皮的可溶性糖、可溶性蛋白质、总黄酮、总多酚含量与茶枝柑果皮相比均差异显著;采用GC-MS法检测出茶枝柑果皮精油的成分主要是D-柠檬烯、萜品烯、γ-松油醇、2-甲氨基-苯甲酸甲酯等,3种典型柑橘皮原料中的精油特征成分及D-柠檬烯含量与茶枝柑最为接近的均为脐橙。综合以上分析可知,脐橙作为广陈皮原料的替代品是最具前景的。     

酸性电解水结合复合膜对橘柚保鲜效果的研究

为了防止橘柚采后枯水腐烂,采用酸性电解水浸果处理,并结合海藻酸钠、羧甲基纤维素钠、茶多酚、抗坏血酸配制成的复合保鲜剂进行涂膜处理后,将橘柚果实置于温度为 (8±1)℃、湿度为75%~80%的条件下存放120 d,以好果率、失重率、细胞膜透性、可滴定酸度、可溶性固形物以及类胡萝卜素为指标进行保鲜效果的评价,通过正交试验确定最佳保鲜方法。本研究所用的复合膜是多孔网络结构的薄膜,空隙小而细腻、均匀分散,复合膜处理后的果皮表面平整光滑,断面结构致密,在果实表面形成屏障。结果表明：酸性电解水处理能有效控制橘柚果实采后病害的发生,复合膜处理可以较好地控制橘柚的腐烂和失水现象,延缓果实衰老,有效保持可滴定酸和可溶性固形物的含量,还能提高果皮色泽;正交试验优化得出最优的保鲜方法,以有效氯含量为30 mg/L的酸性电解水浸果15 min,并联合海藻酸钠0.5%、羧甲基纤维素钠0.5%、茶多酚2.0%、抗坏血酸1.0%配比组合下的复合保鲜剂涂膜20 min。因此认为,酸性电解水结合复合膜处理能提高采后橘柚的品质、延长果实保鲜期。     

科技文摘

据统计,全世界有果树134科,659属,2792种,分水果和坚果两大类.水果类主要包括葡萄、苹果、梨、桃、油桃、甜橙、宽皮甜橙、柠檬、柚、香蕉、菠萝等.坚果主要指核桃、栗子、扁桃、腰果、榛子等.水果的产量占果品总产量的99%.世界果树分市以亚洲为最多,占世界果品总产量的29%,其次是欧洲,占25%.按品种分,葡萄、梨、桃、油桃、李、扁桃、杏仁等以欧洲为多;海枣、柑桔、核桃、香蕉、榛子、阿月浑子,腰果以亚洲为多.近20年来,由于人们生活水平的逐步提高,对食品的需求,已开始转向讲求营养的方向发展.果品中,含有大量的维生素、微量元素等维持人体生命的必需物质,人们把它作为不可缺少的食品,需求量迅速增长.1965年世界年均水果产量为1.83亿吨,而1984年却达到3.01亿吨,20年来水果产量增长了64%,坚果增长了40.4%.     

花生品种不同籽仁部位抗氧化能力研究

以抗活性氧活力单位、抗超氧阴离子活力单位和总抗氧化活力单位为指标,研究了白皮花生、红皮花生、黑色花生、彩色花生、花育16号等不同品种花生籽仁各部位的抗氧化能力。结果表明,花生品种的抗氧化性存在显著的品种差异,籽仁各部位的抗氧化能力品种间有很大差异。花育22号子叶抗活性氧活力单位最高为22.61 U/mg,花育17号子叶总抗氧化能力最高;白沙1016胚的抗活性氧活力单位最高为22.37 U/mg,抗超氧阴离子及总抗氧化能力则以黑色花生、彩色花生和花育22号较高;种皮的抗氧化能力以红皮花生、黑色花生、白沙1016、花育23号和鲁花12号较高,说明黑色花生、彩色花生、白沙1016和花育22号具有较强的抗氧化能力。     

金柑果皮精油超声波辅助提取工艺优化及其抑菌、抗氧化活性

采用响应面法对金柑果皮精油超声波辅助提取提取工艺条件进行优化,并对金柑果皮精油的抑菌和抗氧化活性进行评价。结果表明,金柑果皮精油超声波辅助提取的最佳工艺条件为:液料比27∶1 m L/g、超声时间1.25 h、超声波功率300 W。在此条件下,金柑果皮精油得率为2.24%,与理论预测值基本一致。金柑果皮精油对金黄色葡萄球菌、大肠杆菌、沙门氏菌、黑曲霉、酵母菌均有一定抑制作用,最小抑菌浓度分别为1.0%、0.5%、0.5%、0.5%、0.1%。抗氧化活性结果表明,金柑果皮精油对食用油脂的货架期有一定的延缓作用,具有一定的清除羟自由基、DPPH自由基的能力和总抗氧化能力。     

柚子不同品种及果实不同部位品质差异研究

以瑞丽地区种植的水晶蜜柚、琯溪蜜柚、西柚、红玉香柚 4 个品种的柚子为试材，研究了 4 个品种柚子果实 品质在品种间及果蒂部、赤道部、果脐部、全果的差异。结果表明，各品种间的果实品质差异较大，西柚单果重最小， 为椭圆形，与其他 3 个品种单果重存在显著性差异（p≤0.05），而其他 3 个品种单果重之间差异不显著（p>0.05）， 为长圆形。琯溪蜜柚皮重占单果百分率最低，可食率最高；水晶蜜柚皮重占果重百分率最高；而红玉香柚可食率最低， 且果实的种子数最多，每个果实种子数平均有 108 粒。每一个品种果实不同部位间的皮重占单果百分率均差异显著 （p≤0.05），全果的皮重占果重百分率及可食率均与果脐部接近。琯溪蜜柚果实可溶性固形物（TSS）最高，西柚最 低；水晶蜜柚可滴定酸（TA）最低，西柚最高；水晶蜜柚的固酸比（TSS/TA）最高，西柚最低；水晶蜜柚的维生素 C 含量最低，其他 3 个品种差异不显著（p>0.05）。水晶蜜柚和琯溪蜜柚全果 TSS、TA、TSS/TA 和维生素 C 含量均与果 脐部接近，而西柚和红玉香柚各个部位 TSS、TA、TSS/TA 和维生素 C 含量差异不显著（p>0.05）。感官品质方面，综 合 9 个指标检测结果，水晶蜜柚的风味分数和综合满意度最高。综上所述，水晶蜜柚果实酸甜度适中、果实肉嫩、风 味较好，是瑞丽当地最受欢迎的品种，但单果不同部位间品质差异较大，需要不断改良提高单果品质的均一度；西柚 较酸，但单果间品质差异较小，且汁多、化渣性最好，具有较大的发展潜力。     

Antioxidant properties of peel and pulp hydro extract in ten Persian pomegranate cultivars

This study compares the antioxidant activity of ten different pomegranate cultivars grown in Iran using the ferric reducing power assay (FRAP assay), which is based on the reduction of a ferric-tripyridyl triazine complex to its ferrous, colored form in the presence of antioxidants. Aqueous solutions of known Fe(+2) concentration, in the range of 100-1000 micromol L(-1) were used for calibration. The results showed that among pulp and peel fractions the sour alac and sweet white peel cultivars had more FRAP value respectively. The pomegranate peel extract had markedly higher antioxidant capacity than the pulp extract. The peel extract of sweet white peel cultivar appeared to have more potential as a health supplement rich in natural antioxidants compared to the pulp and peel extracts of other pomegranate cultivars.     

柚子不同品种及果实不同部位品质差异研究

以瑞丽地区种植的水晶蜜柚、琯溪蜜柚、西柚、红玉香柚 4 个品种的柚子为试材,研究了 4 个品种柚子果实品质在品种间及果蒂部、赤道部、果脐部、全果的差异。结果表明,各品种间的果实品质差异较大,西柚单果重最小,为椭圆形,与其他 3 个品种单果重存在显著性差异（p≤0.05）,而其他 3 个品种单果重之间差异不显著（p>0.05）,为长圆形。琯溪蜜柚皮重占单果百分率最低,可食率最高;水晶蜜柚皮重占果重百分率最高;而红玉香柚可食率最低,且果实的种子数最多,每个果实种子数平均有 108 粒。每一个品种果实不同部位间的皮重占单果百分率均差异显著（p≤0.05）,全果的皮重占果重百分率及可食率均与果脐部接近。琯溪蜜柚果实可溶性固形物（TSS）最高,西柚最低;水晶蜜柚可滴定酸（TA）最低,西柚最高;水晶蜜柚的固酸比（TSS/TA）最高,西柚最低;水晶蜜柚的维生素 C含量最低,其他 3 个品种差异不显著（p>0.05）。水晶蜜柚和琯溪蜜柚全果 TSS、TA、TSS/TA 和维生素 C 含量均与果脐部接近,而西柚和红玉香柚各个部位 TSS、TA、TSS/TA 和维生素 C 含量差异不显著（p>0.05）。感官品质方面,综合 9 个指标检测结果,水晶蜜柚的风味分数和综合满意度最高。综上所述,水晶蜜柚果实酸甜度适中、果实肉嫩、风味较好,是瑞丽当地最受欢迎的品种,但单果不同部位间品质差异较大,需要不断改良提高单果品质的均一度;西柚较酸,但单果间品质差异较小,且汁多、化渣性最好,具有较大的发展潜力。     

Use of Banana (<Emphasis Type="Italic">Musa acuminata</Emphasis> Colla AAA) Peel Extract as an Antioxidant Source in Orange Juices

Using banana peel extract as an antioxidant in freshly squeezed orange juices and juices from concentrate was evaluated. Free radical scavenging capacity increased by adding banana peel extracts to both types of orange juice. In addition, remarkable increases in antioxidant capacity using 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical were observed when equal or greater than 5 mg of banana peel extract per ml of freshly squeezed juice was added. No clear effects were observed in the capacity to inhibit lipid peroxidation. Adding 5 mg banana peel extract per ml of orange juice did not substantially modify the physicochemical and sensory characteristics of either type of juice. However, undesirable changes in the sensory characteristics (in-mouth sensations and colour) were detected when equal or greater than 10 mg banana peel extract per ml of orange juice was added. These results confirm that banana peel is a promising natural additive that increases the capacity to scavenge free radicals of orange juice with acceptable sensory and physicochemical characteristics for the consumer.     

Evaluation by PCR of Xylella fastidiosa subsp. pauca transmission through citrus seeds with special emphasis on lemons (Citrus limon (L.) Burm. f)

Citrus variegated chlorosis (CVC), caused by the xylem-limited bacterium Xylella fastidiosa subsp. pauca (Xfp), is a damaging disease of sweet oranges (Citrus sinensis (L.) Osbeck) in several citrus production areas of South America. CVC was first identified in sweet orange orchards in the Northwest region of São Paulo State, Brazil. Transmission of Xfp from seed of CVC infected sweet orange fruit to seedlings has been reported. However, Xfp has not been reported to infect or cause CVC in lemon (Citrus limon (L.) Burm. f). Therefore, the objectives of this study were 1) to further evaluate the potential for vertical transmission of the bacterium through sweet orange seeds originating from symptomatic fruits to sweet orange seedlings and 2) to examine lemon trees and seeds for PCR detection of Xfp. Based on our evaluations, Xfp was not detected by PCR in leaves and seeds of different lemon cultivars surrounded by sweet orange orchards with high incidence of CVC. Furthermore, we could not detect with PCR that Xfp is vertically transmitted through sweet orange seeds to seedlings of sweet orange even from fruits with typical CVC symptoms. Hence, in this study and with the cultivars tested, Xfp was not confirmed by PCR detection to be transmitted via infected seeds from fruits of Citrus spp. even in areas where CVC is endemic nor was lemon found to be a natural host of Xfp.     

Improving the Efficiency of Antioxidant Extraction from Mango Peel by Using Microwave-assisted Extraction

The purpose of this study was to analyze the extraction efficiency of antioxidants from mango peel by comparing two techniques: microwave-assisted (MAE) and traditional solvent (TE) extraction. The number of extraction steps, water content in the extractant, peel weight-to-solvent volume ratio in extractions and extraction time all had an influence on obtaining extracts with high antioxidant capacity, but the extraction technique and the water content in the extractant were the factors with the greatest effect. Using three steps, a water content of 50 % in the ethanol:water extractant, an extraction time of 60 min and a weight-to-volume ratio of 1:10 or 1:50 (w/v) led to the highest antioxidant activity and phytochemicals content in extracts. The extraction time needed to extract phytochemicals from mango peel was similar when MAE and TE were used. However, the antioxidant capacity and phytochemical content were around 1.5–6.0 times higher in the extracts obtained by MAE.     

High potential of agro-industrial by-products of pomegranate (Punica granatum L.) as the powerful antifungal and antioxidant substances

Microorganisms such as fungi are one of the most important factors that cause oxidative processes during postharvest stage and consequently deterioration of agriculture products would not be unexpected. On the other hand, high antioxidant properties of industrial by-products of pomegranate propose them as powerful antioxidant and antifungal substances. So to investigate the antioxidant and antifungal properties of pomegranate, two independent factorial experiments based on randomized design with 5 replications were conducted. In the first experiment the effect of 3 different parts of pomegranate (peel, seed and leaf) and 2 different kinds of extracts (aqueous and methanolic) with 4 concentrations (0, 500, 1000 and 1500 ppm) were investigated on 3 postharvest fungi (Penicillium italicum, Rhizopus stolonifer and Botrytis cinerea). In the second experiment antioxidant capacity and phenolic content were measured for two different extracts from different parts. Based on the results the methanolic extract showed the highest inhibitory effects on the mycelia growth (IMG) and spore germination (ISG) with 49.82 and 41.25% respectively. On the other hand, peel and seed extracts had more inhibitory effect (IMG and ISG) than leaf extract. The phenolic content of peel extract were also measured 2.8 fold higher than pomegranate leaf extract and antioxidant capacity of peel, seed and leaf extracts of pomegranate were 55.3%, 35.7% and 16.4% respectively. Therefore, it seems that the high percentage of phenolic content in the peel and seed of pomegranate could cause the high antifungal and antioxidant activity of their extracts.     

甜橙Dof基因家族鉴定与表达分析

为研究甜橙单锌指DNA结合蛋白（DNA binding with one zine finger, Dof）家族的进化关系和该家族成员在不同花期甜橙品种花芽和叶片的表达模式,利用甜橙基因组筛选鉴定CsDof基因家族成员,对甜橙Dof基因家族成员及启动子区进行生物信息学分析,并使用qRT-PCR检测不同花期甜橙品种中CsDof家族成员在成花时期的表达情况。共鉴定出24个CsDof基因家族成员,这些基因分布在甜橙的8条染色体上。系统进化树聚集为9个亚群,CsDofs被分在A、B1、B2、C1、C2.1、C2.2、D1和D2亚群,同一亚群的CsDofs具有相似的基因结构和基序分布。CsDofs启动子区域含大量的光响应元件和激素响应元件。qRT-PCR检测分析发现2个甜橙品种花芽和叶片组织中的CsDofs表达模式存在较大差异,对照品种‘纽荷尔’花芽和叶片中CsDof6、CsDof11、CsDof13、CsDof17和CsDof21表达量均高于早熟品种‘赣南早’,而‘赣南早’花芽和叶片中CsDof19和CsDof23表达量高于‘纽荷尔’,表明CsDofs在不同花期的甜橙中具有明显的品种表达特异性,推测CsDofs对甜橙开花时间起重要的调控作用。这些结果为阐明CsDof基因家族在甜橙花期调控中的功能提供了理论参考。     

超声辅助提取澳洲坚果青皮总黄酮工艺优化及抗氧化性能研究

以澳洲坚果青皮为原料,研究了超声辅助提取总黄酮工艺条件以及抗氧化活性。通过L₉(3 ⁴)正交试验得到超声功率为300 W条件下的最佳提取工艺:提取时间为45 min、乙醇浓度为50%、提取温度为50 ℃、料液比为1:60 （g/mL）,在此条件下总黄酮提取量为(1638.59±44.26) mg/100 g。通过抗氧化实验发现,澳洲坚果青皮总黄酮ABTS自由清除能力约为Trolox的2.48倍,总抗氧化还原能力约为Trolox的1.90倍,由此表明澳洲坚果青皮总黄酮具有较强的抗氧化活性。