黄芪原药材及饮片中7种金属含量分析

目的优化元素测定时样品湿法消解的方法,分析黄芪原药材及饮片中Al、As、Cd、Pb、Cu、Ni、Zn7种金属的含量。方法样品加入10 mL HNO_3-HC1O_4(4:1,V:V)混酸过夜后,在赶酸前加入4 mL 30%H_2O_2溶液,采用电感耦合等离子体发射光谱法(inductively coupled plasma optical emission spectrometery,ICP-OES)测定7种金属元素的含量;将检出的As、Cd、Pb、Cu及Al、Ni、Zn的含量分别与各元素的限量标准比较,计算超标率。结果各金属元素在0.2～20μg/mL范围内线性关系良好,加标回收率为75%～125%,相对标准偏差为1.20%～2.14%。检出限为0.0021～0.0702μg/mL,定量限为0.0063～0.2106μg/mL。黄芪中As、Pb、Cd、Ni4种重金属均未检出,Al、Zn、Cu 3种金属元素均有检出;检出的Cu均不超标,Al、Zn2种元素都超标;饮片中A1和Zn的超标率均为60%。本研究分析的黄芪样品未受到As、Pb、Cd、Ni 4种重金属的污染,Cu虽然有检出,但其含量并未超过相关标准,Al、Zn污染相对比较严重。结论本方法准确,灵敏,适用于黄芪中多种金属元素的分析。     

桑果中金属元素含量的测定

本文采用原子吸收、原子荧光法测定4种桑果中金属元素的含量。结果表明,新疆4种桑果中除含有较高浓度的人体所需的金属元素Ca、Fe外,对人体有益的微量元素Cu、Mn、Zn的含量也较丰富。4种桑果中的重金属元素Hg、As、Cd均低于国家标准限量值（GB 2762—2022）;除库车黑桑果中的Pb未超标,其他3种桑果中的Pb含量均略高于国家标准限量值。     

茵陈蒿叶的金属元素研究

采用电感耦合等离子体质谱(ICP-MS)法测定茵陈蒿的叶中的金属元素的分布状况。结果表明:含量多的金属元素有Mg、Al、Fe、Mn、Ba、Zn等,茵陈蒿的叶中金属元素在不同的地区有含量的差异,Pb含量低于世界卫生组织(WHO)草药重金属限量标准,部分地区Cd含量高于WHO重金属限量标准。采集地区的茵陈蒿叶不具备富集Zn、Cu、Cd的吸收能力。Be、Cu、Se、Ag、Sb、Tl大多未检出,V、Co、Ni、Mo含量在0.0~1.5 mg/kg之间。     

辽西地区食用鱼中重金属含量的测定及食用安全性评价

经微波消解处理样品,采用石墨炉原子吸收光谱法测定辽西地区常见食用鱼中肉、鳃和内脏3个组织器官内Cd、Cr、Cu、Fe、Pb、Zn六种元素的含量。方法相对标准偏差0.54%～2.03%,加标回收率94.0%～110.0%。结果表明：所检测鱼中Fe、Zn、Cu含量较高,Cd、Cr、Pb含量较低;鱼内脏和鳃中的重金属含量高于鱼肉;Cr、Zn和Cu的含量均低于国家食品限定量;部分鱼样中Cd和Pb的含量超标,但未超过暂定每周可耐受摄入量。因此辽西地区市售所检测鱼种可食用,但仍有必要降低摄入量。     

吉林省部分市售小麦粉中20种金属元素的含量分析

目的研究吉林省部分市售小麦粉中Fe、Ag、Al、As、Ba、Be、Cd、Co、Cr、Cu、Mn、Mo、Ni、Pb、Sb、Se、Tl、V、Zn、U等20种金属元素的含量情况,有助于摸清小麦粉中各元素的本底及污染情况,为吉林省食品安全监管提供科学依据。方法收集吉林省9市州样本共计72份,用微波消解前处理-电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)测定样品中各元素含量。结果检测72份小麦粉中20种金属元素,除Be、Ag、Sb、TI、U 5种元素未检出外,其余各元素的检出平均值依次为Fe(11.1mg/kg)、Zn(5.77 mg/kg)、Mn(5.12 mg/kg)、Al(3.33 mg/kg)、Cu(1.36 mg/kg)、Ba(0.59 mg/kg)、Mo(0.23 mg/kg)、Co(0.16 mg/kg)、Cr(0.10 mg/kg)、Ni(0.080 mg/kg)、Se(0.075 mg/kg)、Pb(0.027 mg/kg)、V(0.025 mg/kg)、As(0.021 mg/kg)、Cd(0.013 mg/kg)。Cr、As、Cd、Pb含量合格率100%。结论小麦粉中金属元素未发现有超标现象,可以正常食用,对于元素铅的普遍检出问题及个别样品中铅检出值较高问题应引起重视。     

火焰原子光谱法测定饲料和不同种类鸡蛋中的微量元素

采用湿法消解处理样品,火焰原子吸收光谱法测定饲料和来自该饲料喂养的不同种类鸡所产的鸡蛋中微量元素Cu、Zn、Mn 、Pb和Cd的含量,分析了饲料和鸡蛋中Cu、Zn、Mn 、Pb和Cd的含量差别。结果表明：饲料中的元素含量Cu、Zn和Mn 远远高于鸡蛋中的相应元素的含量,Pb、Cd在饲料和鸡蛋中的含量差别不大,5种元素在不同饲料中的含量差别很大而鸡蛋中的含量差别不大;同种元素在蛋清和蛋黄中的含量不同,蛋清中的含量低于在蛋黄中的含量。各元素测定的精密度在0%～7.2%,加标回收率为80%～109%。     

ICP-AES法测定水产品贝壳肉中16种金属元素

利用ICP-AES法测定钱塘江近海水域水产品贝壳肉中Al、Ca、Cr、Cu、Fe、Mg、Mn、Ni、Se、Sb、Sn、V 、Zn、Cd、As、Pb、Hg十六种金属元素含量。结果表明:所采样品金属元素含量丰富,对铅、铝的吸附量相对较高,部分样品金属元素含量相对偏高,不宜多食。ICP-AES法具有检测灵敏度高、回收率好、快速、简便等好的检测效果。     

顺义区四种蔬菜重金属残留健康风险分析

参照重金属检测国家标准,采用原子吸收光谱法分别对4种茄果类蔬菜120个蔬菜样品Pb,Cd,Cu和Zn的重金属元素的含量进行了测定,并利用单因素法和内梅罗指数法评价蔬菜重金属污染情况,健康风险评价模型对当地居民摄食蔬菜导致的健康风险进行了评价和分析。结果表明,4种检测样品中均有重金属Pb含量超标,Cd只在茄子中超标,综合污染指数都小于1,处于警戒级。通过蔬菜途径导致的Pb,Cd,Cu和Zn的THQ值分别为1.59×10-7,2.85×10-5,7.49×10-7和9.29×10-9 mg/(kg·d),联合THQ值为2.89×10-5,低于美国环保局与国际放射防护委员会分别推荐的标准,即当地居民经茄果类蔬菜途径摄入重金属引起的人体健康风险较低。     

安徽省不同品种茶叶中微量元素含量分析

有关茶叶对人体保健作用的研究很多,但是对茶叶中微量元素含量的测定的报道非常少。茶叶中含有Mn、Fe、Zn、Cu、Pb等多种微量元素,有些微量元素可作为多种酶的激活剂、造血原料,参与细胞分裂、核酸代谢、结缔组织代谢,但有些元素含量超标则对人体是有害的。本实验利用原子吸收光谱法测定来自安徽省不同品种、不同产地的7个茶叶样品中Cu、Fe、Mn、Zn、Pb五种元素的含量。结果表明:茶叶样品中5种元素的含量为Mn>Fe>Zn>Cu>Pb,不同品种茶叶样品中的Fe含量有显著差别,Pb在茶叶样品中含量极小,但都低于国际标准规定的最低阈值以下。因而分析它们在茶叶中的含量对于不同品种茶叶的开发利用有一定的实际意义。     

河北烤烟中11种微量元素含量分析

采用微波消解-电感耦合等离子体质谱法,测定河北省石家庄、保定、蔚县3个烤烟主产区不同部位烟叶样品中11种微量元素(Cr,Co,Ni,Se,Mn,Zn,Cu,As,Cd,Pb,Hg)含量.结果表明:烤烟中微量元素含量呈现地域性差异,Mn,Cu,Zn,As和Pb含量差别较大;不同部位烤烟中各微量元素含量呈现规律性分布,Cu在中、上部叶片含量较高,其余微量元素在下部叶含量较高;Mn在测定的元素中含量最高,具有潜在生理毒性的Cu,Cr,Cd,Pb,Ni,Hg,As含量较低,均达到无公害烟叶生产示范区水平.     

猕猴桃品种对猕猴桃脆片品质影响的评价

目的:以6个品种的猕猴桃为原料,筛选出最适合加工成脆片的品种。方法:采用真空冷冻干燥的方法制备猕猴桃脆片,测定猕猴桃脆片的得率、脆片中水溶性果胶含量、酸溶性果胶含量、可溶性糖含量、总酸含量、糖酸比、抗坏血酸含量及脆片的硬度和脆度等9个指标,并对猕猴桃脆片进行感官评价。结果:不同品种猕猴桃脆片的得率、营养物质含量和感官指标不同。其中金艳猕猴桃脆片的得率、水溶性果胶含量、可溶性糖含量和硬度较高,总酸含量和脆度较低;金梅猕猴桃脆片的得率、水溶性果胶含量、可溶性糖含量和抗坏血酸含量较高,总酸含量、硬度和脆度较低;金圆猕猴桃脆片的水溶性果胶、酸溶性果胶、结合果胶、可溶性糖、总酸和抗坏血酸含量较高,脆片的硬度和脆度较低;金桃猕猴桃脆片的得率、糖酸比、抗坏血酸等含量及脆片的硬度和脆度较高,脆片的水溶性果胶和总酸含量较低;翠玉猕猴桃脆片的得率、糖酸比和脆度较高,脆片的酸溶性果胶含量、结合态果胶含量、可溶性糖含量、总酸含量和脆片的硬度较低;东红猕猴桃脆片的得率、酸溶性果胶含量、结合态果胶含量、可溶性糖含量、糖酸比和脆片的硬度较高,脆片中水溶性果胶含量、总酸含量和脆片的脆度较低。结论:品种对猕猴桃脆片的得...     

湘西猕猴桃籽成分分析及猕猴桃籽油的特性研究

分析了湘西猕猴桃籽的主要成分,同时采用水酶法提取猕猴桃籽油,并对猕猴桃籽油的特性进行了研究。结果表明:湘西猕猴桃籽粗脂肪含量32.19%,粗蛋白质含量16.06%;猕猴桃籽中氨基酸种类不全,缺少2种氨基酸,属于不完全蛋白质;鲜味谷氨酸(Glu)和天门冬氨酸(Asp)含量很高,分别为6.1 mg/g和3.5 mg/g,占氨基酸总量的25.98%,为猕猴桃籽增添了良好的风味;水酶法提取猕猴桃籽油总出油率为25.89%,萃取率达80.45%;猕猴桃籽油中亚麻酸含量高达60.59%,不饱和脂肪酸含量达89.92%,生育酚含量为812.41 mg/kg。     

Thaumatin-like protein in kiwifruit

A 21-kDa protein extracted from woody tissue underlying the pedicel of kiwifruit (Actinidia deliciosa var deliciosa [A Chev] Liang and Ferguson) was purified to homogeneity by cation exchange, gel filtration, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) on a 15% gel and electro-transfer onto a polyvinylidene difluoride (PVDF) membrane, followed by excision of the band of interest. Amino terminal sequence analysis of this band revealed a high degree of homology with basic endochitinase (EC 3.2.1.14) in orange and thaumatin-like proteins in tobacco, barley, maize and tomato. This is the first record of a thaumatin-like protein in a subtropical berryfruit. Potential implications of this finding and the need for future research are discussed. © 1999 Society of Chemical Industry     

Actinidin in kiwifruit cultivars

Actinidin content was determined in four kiwifruit cultivars: Hayward, Abbot, Bruno and Monty, all grown in Spain. The flesh contains the highest actinidin activity, followed by the zones with seeds and core. Among the four cultivars assayed, Bruno and Hayward had the greatest activity of actinidin in the flesh (Zone A). The molecular weight determined by gel electrophoresis for actinidin was 28 kDa. Kiwifruit could be a good source of proteinases in countries which do not grow papaya and pineapple.

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Actinidin-Gehalt verschiedener Kiwi-Sorten

Zusammenfassung Die Aktinidin-Aktivität von vier Kiwivarietäten, nämlich Hayward, Abbot, Bruno und Monty, die in Nordspanien gezüchtet werden, wurde untersucht. Das Fruchtfleisch zeigte die größte Aktivität, nachfolgend die Samenzone und das Endokarp. Unter den vier untersuchten Sorten zeigten Hayward und Bruno die größte Aktivität. Man kann die Kiwi analog zu Ananas und Papaya zur Gewinnung von Proteinase benutzen.

     

Volatile aroma constituents of kiwifruit

The volatile constituents of kiwifruit (Actinidia chinensis Planch.) have been investigated. The volatiles were collected and concentrated using vacuum steam distillation and freeze concentration. The concentrated distillate was analysed by gas chromatography, gas chromatography-mass spectrometry and reaction gas chromatography. Apart from methyl benzoate, all the components identified were alkyl and alkenyl esters, alcohols, aldehydes and ketones. The most abundant component was trans hex-2-enal. Odour evaluation of the components at the exit port of the gas chromato-graph indicated that ethyl butanoate, hexanal and trans hex-2-enal are important contributors to the aroma of kiwifruit. One other component which does not show a peak in the chromatogram and which is not yet completely characterised may have particular significance.     

Consumer-driven product development in the kiwifruit industry

In today's business environment, a continuous supply of novel products is essential to retaining competitive advantage. Consequently, the fruit industry is under pressure to develop new cultivars. The present study describes the application of preference mapping methodology to aid product development in the kiwifruit industry. Recently, a new yellow-fleshed, sweet and fruity flavoured cultivar of kiwifruit was launched on the marketplace. In this study, a comparison of consumer preferences for this new type of kiwifruit with that of the familiar green-fleshed and sweet-tart tasting kiwifruit was undertaken. Using fruit from eight different genotypes consumer preferences for these two distinctly different types of kiwifruit were explored. Acknowledging the problems associated with sensory evaluation of fruit like kiwifruit, which ripens rapidly, careful attention was given to ensuring optimum fruit quality and even ripeness of samples presented to consumers, as well as sensory panellists. A segmented population with respect to liking of yellow-fleshed kiwifruit genotypes was observed. Consumers’ acceptance of the yellow kiwifruit was not related to trait food neophobia.     

Determining consumer purchase intentions: the importance of dry matter, size, and price of kiwifruit

Abstract: Knowledge of the relative importance of food quality attributes in determining consumer purchase intention is critical for robust assessment of economic opportunities for industry growth. The aim of this study is to demonstrate how conjoint analysis methodology that incorporates tasting of fruit can be used to collect such information. Three hundred Japanese consumers took part in research designed to measure the importance of dry matter (DM), size, and price of kiwifruit (Actinidia deliciosa “Hayward” and Actinidia chinensis “Hort16A”) for purchase intention. Measurement of consumer liking for kiwifruit of different DM content was a key first step. Liking increased as DM increased and was accompanied by increased purchase likelihood/choice probability for kiwifruit. The size of kiwifruit presented to consumers varied from “small” to “extra large.” Consumers liked “mid‐sized” kiwifruit over “small” or “extra‐large” kiwifruit. Despite these differences in liking, size was of little importance in determining purchase likelihood/choice probability for kiwifruit. Price was a very important factor in determining purchase likelihood/choice probability but was less important than DM content. As price increased, purchase likelihood/choice probability decreased. Beneath these general findings, heterogeneity existed. Some consumers placed more/less importance on the focal purchase drivers than suggested by the aggregate model. Overall, the results suggest that incentive schemes already implemented by industry should consider rewarding high‐DM fruit more than fruit size. Practical Application: This research has contributed to the New Zealand kiwifruit industry gaining a better understanding of the relative importance consumers place on DM, size, and price of kiwifruit and has resulted in changes to grower incentive schemes. The research approach presented forces consumer to tradeoff attributes of kiwifruit against each other and decide on how important two key quality attributes—DM and size—are relative to each other and relative to price. The application of conjoint analysis in this article can be transferred to other fruits, food, and beverages and help guide consumer‐led innovation.     

猕猴桃干酒生产工艺研究

研究了猕猴桃干酒的生产工艺和关键工艺措施,并对猕猴桃酿酒适应性和猕猴桃干酒理化指标进行了探讨。     

猕猴桃加工、研究现状

介绍了猕猴桃果实保健功能及其果实中的化学成分,综述了猕猴桃果实加工成果汁、果酒、果脯的加工研究状况以及对猕猴桃中的挥发性物质、蛋白酶、淀粉、多酚等成分的研究状况。     

New strategies for kiwifruit processing

Improved strategies are presented for recovering the chloroplast fraction from kiwifruit. One strategy is to extract chlorophyll from the 'peel', i.e. the outer 29% of the fruit, the remainder being processed to juice by conventional methods with the sacrifice of its chlorophyll content. This strategy recovers two-thirds of the chlorophyll content of the fruit and speeds the overall processing. A second strategy facilitates processing by washing the screens used for separating fruit tissues from chloroplast-containing juice. the washing with fine water jets cleans the screens in situ of the kiwifruit slime. It was also shown that chloroplast extracts when stored in a domestic freezer are stable for at least one year. Recombined frozen kiwifruit products such as sorbet and ice-cream are chlorophyll-colour stable for at least 7 months.