Quantitative Analyses of Major Carotenoid Fatty Acid Esters in Fruits by Liquid Chromatography: Persimmon and Papaya

A procedure for the quantitative analyses of major carotenoids and carotenoid esters in persimmons and papayas using column and liquid chromatography is described. The carotenoids and carotenoid esters were first separated by column chromatography on alumina into three fractions by elution with petroleum ether-benzene (80:20), benzene and methanol. The column fractions were further separated by reversed phase liquid chromatography and characterized. The total carotenoid contents in persimmon and papaya calculated as beta-carotene equivalents were 43 and 25 μg/g, respectively. The major carotenoids in persimmon were beta-cryptoxanthin, zeaxanthin, beta-carotene, lycopene and antheraxanthin and the major carotenoids in papaya were beta-cryptoxanthin, cryptoxanthin 5,6-epoxidc, beta-carotene and antherxanthin. The xanthophylls were acylated with C₈ to C₁₆ saturated fatty acids.     

HPLC Determination of Carotenoids in Fruits and Vegetables in the United States

A study was conducted to determine alpha- and beta-carotene and beta-cryptoxanthin in twenty-two fruits and vegetables. Foods were obtained from wholesale distributors from five locations throughout the United States (Los Angeles, Dallas, Chicago, Miami, and Boston) three times during a year (November, March, and July). Mean vitamin A activity in retinol equivalents (RE) of each food along with average values for the individual carotenoids (μg/100g) are given. beta-Carotene was the most prevalent carotenoid. Carrots, beet greens, spinach, swiss chard and sweet potatoes had the most vitamin A activity. Analysis of variance indicated that there were no significant differences among either locations or time of analysis. A comparison was made between the new values and the ones listed in USDA Handbook No. 8 and revised Handbook No. 8–9. There were differences between the old and new values in 14 of the 22 fruits and vegetables analyzed.     

盐藻中类胡萝卜素的高效液相色谱分析

采用Nova PakC18和Bond PakC18两种色谱柱对盐藻中的类胡萝卜素进行了高效液相色谱分析和比较,结果表明在流动相、流速、温度、检测波长等相同的条件下,Bond PakC18对盐藻中类胡萝卜素的分离效果明显好于Nova PakC18。对Bond PakC18分析结果进行了定性分析,初步确定盐藻含有的类胡萝卜素有16种以上。     

Development of a Method for the Quantitative Estimation of Provitamin A Carotenoids in Some Fruits

A procedure for the quantitative estimation of provitamin A carotenoids beta-carotene, cryptoxanthin and cryptoxanthin esters in some fruits using conventional column and high performance liquid chromatography was developed. The provitamin A carotenoids were first separated by column chromatography on alumina prior to furthur separation and quantitation by reversed phase liquid chromatography. The distribution of provitamin A carotenoids in fruits varied. Among the provitamin A rich fruits, apricot, mango, and cantaloupe contained essentially beta-carotene whereas cryptoxanthin accounted for nearly half the total carotenoids in papaya, persimmon, and tangerine. Peach, red bell papper, oranges and red grapefruits were intermediate in their provitamin A content while tomato, yellow bell pepper, pineapple and watermelon were poor sources. Cryptoxanthin occurred acylated with C₈ to C₁₈ saturated fatty acids in the fruits analyzed.     

反相C30柱在HPLC分析类胡萝卜素中的应用

本文介绍了一种最近在类胡萝卜素高压液相色谱分析中非常引人注目的固定相-反相C30梓，并例举了这种柱子在食品-特别在植物食品-的类胡萝卜素分析中的一些应用实例。与反相C30同定相相比，C30同定相分离类胡萝卜素的几何异构体具有明显的优势。因此，可以认为：应用反相C30柱分析生物样品-特别是食品材料-中的类胡箩卜素会具有良好的前景。     

Carotenoid Content and Vitamin A Activity of Some Common Cultivars of Mexican Peppers (Caps&m annuum) as Determined by HPLC

Alpha-, beta, and gamma-carotenes, β-cryptoxanthin and total vitamin A activity in five different immature cultivars of peppers (Cupsicum annuum), commonly consumed in the Northwest region of Mexico, were determinated by high performance liquid chromatography (HPLC). Among the cultivars studied, “Poblano” pepper had the highest provitamin A (111.4±28.2 μg Retinol Equivalents (RE)/100g) followed by “Serrano” (86.7 ±13.0), “Jalapeño” (67.0±8.7), “Verde” (30.2±3.0), and “Caribe” (2.2 ± 0.9). In general, these values were higher than the vitamin A of peppers reported by the Mexican food composition tables and lower than the data presented in the INCAP/ICNND food composition tables for USC in Latin America.     

高效液相色谱法测定鸡蛋、鸡肉中五种类胡萝卜素物质

本文研究了鸡蛋、鸡肉中虾青素、叶黄素、斑蝥黄、玉米黄素、β-胡萝卜素等5种类胡萝卜素同时检测的HPLC方法。结果表明,5种类胡萝卜素在0.5~100 μg/mL线性范围内有较好的线性关系,决定系数R2均大于0.996,方法的检出限均在0.10~0.20 mg/kg之间,定量限在0.33~0.66 mg/kg之间。在1、10、20 mg/kg的加标水平下,鸡蛋和鸡肉样品的加标回收率分别在71.6%~112.9%和88.6%~119.7%之间,RSD均≤7.2%。该方法快速简单、准确度高、重复性好,适用于鸡蛋、鸡肉等复杂基质样品中5种类胡萝卜素类物质检测的要求,对于鸡蛋、鸡肉的市场监管具有重要意义。     

高效液相色谱法测定柑橘汁中类胡萝卜素

用正己烷、丙酮、乙醇混合溶剂提取宽皮柑橘大叶尾张中类胡萝卜素,10%KOH的甲醇溶液皂化12h,比较了hypersilODS2和YMCC30两种不同的色谱柱的分离效果。结果表明C30色谱柱分离效果优于hypersilODS2色谱柱。通过类胡萝卜素典型的特征吸收峰,结合在线的PAD检测器,初步判断在C30色谱柱分离的类胡萝卜素有18种。     

HPLC法测定大豆磷脂中卵磷脂含量

应用Lichrosorb si60(5μm)250×4mm色谱柱,乙腈甲醇水(652114v／v)为流动相外标法测定了大豆磷脂中卵磷脂含量、卵磷脂检测线性范围为0．04～0．8mg／ml,r=0.9996,方法的回收率为98．35％,RSD为6．94％(n=6)。     

木鳖果天然类胡萝卜素的研究进展

木鳖果为葫芦科苦瓜属植物,因其含有丰富的番茄红素、β-胡萝卜素、叶黄素等功能性成分而受到国外学者的广泛关注。本文针对木鳖果的植物属性、类胡萝卜素的含量及分布、相关结构及生理功能、提取工艺及稳定性,以及研究进展和存在问题进行较全面阐述。     

Carotenoids and Their Geometry Isomers in Selected Tropical Fruits

This study determined the carotenoids content in cherry tomato, pink guava, and red grapefruit pulps and juices. Cherry tomato pulp exhibited the highest β-carotene content whereas pink guava pulp had the highest lycopene content. However, β-carotene and lycopene contents in the studied fruit juices were lower than their pulps in the same sample portion. Interestingly, six to twelve cis-isomers of carotenoids were identified in the fruit pulps and juices studied. A higher number of trace amounts of cis-carotenoids was found in fruit pulps as compared to juices. Therefore, consumption of whole fruit is recommended as the studied fruit juices have lower carotenoids content.     

Quality of Green Beans, Bell Peppers and Spinach Stored in Polyethylene Bags

Quality attributes of packaged and unpackaged vegetables generally decreased nonlinearly during storage at 10°C or 20°C, and most of the decrease was greater at 20°C than at 10°C. Packaging reduced weight loss of green beans and spinach kept at 20°C; and reduced chlorophyll loss of green beans at 10°C and of spinach at 20°C. Ascorbic acid (vitamin C) benefited by packaging of green beans and spinach kept at 10°C. Packaging had an effect on thiamin (vitamin B₁) of only spinach held at 10°C and 20°C and had no effect on riboflavin (vitamin B₂). Loss of these quality attributes appears to be enhanced with water loss.     

四川泡菜发酵原料-灯笼辣椒附生乳酸菌的抗生素耐药性评估与耐药基因分析

以四川泡菜蔬菜原料——新鲜灯笼辣椒为对象,分析其表面附生乳酸菌Enterococcus mundtii（5 株）、Enterococcus faecalis（2 株）、Enterococcus hirae（5 株）、Lactococcus lactis（7 株）、Leuconostocmesenteroides（2 株）、Leuconostoc holzapfelii（3 株）和Weissella cibaria（79 株）对青霉素（penicillin,PEN）、红霉素（erythromycin,ERY）、四环素（tetracycline,TET）、链霉素（streptomycin,STR）和氯霉素（chloramphenicol,CHL）的抗生素耐药性和耐药基因分布,为制定合理的食品安全防控措施提供科学依据。研究表明：所有分离菌株均无PEN和ERY耐药性,其他种属部分菌株对TET、STR和CHL表现出单一、二重或三重耐药性。除E. hirae、E. faecalis和L. holzapfelii部分菌株对STR表现出单一耐药性外,所有L. mesenteroide菌株只表现出了STR单一耐药性;STR和TET、STR和CHL二重耐药菌株在E. faecalis、E. hirae、L. lactis和W. cibaria分离菌株中都有发现,但是STR、TET、CHL三重耐药菌株仅在W. cibaria中发现。聚合酶链式反应检测发现：除基因norA、sepA、tet(A)、tet(O)和aac(6’)-aph(2’)未被检出外,其他耐药菌株都有相应1 个或多个耐药基因被检出。多重耐药外排泵基因efrA、tolC、norC、sugE和mdfA较核糖体蛋白质保护和酶修饰基因检出率高,分别达到了49%、41%、48%、41%和47%。虽然辣椒表面附生乳酸菌的抗生素耐药基因在四川泡菜发酵过程中的扩散行为需要进一步研究,但根据食品加工过程安全规范标准,也应关注其表面附生的乳酸菌抗生素耐药性存在的潜在食品安全问题。     

高效液相色谱法定量测定果蔬中甲醛含量

通过五氟苯肼与甲醛进行衍生,建立高效液相色谱法定量测定果蔬中甲醛含量的分析方法。样品在温度为60 ℃超声波条件下直接提取衍生30 min,离心纯化后高效液相色谱检测,外标法定量。优化的色谱条件为：XDB-C18色谱柱（4.6 mm×250 mm,5 μm）,流动相：乙腈-水（70∶30,V/V）,流速1.0 mL/min,柱温40 ℃,检测波长258 nm。结果表明,该方法的定量检测限可达到0.114 mg/kg,在0.114～57 mg/L范围内呈良好的线性关系,当甲醛添加量分别为1.14、8.55、17.10 mg/kg时,平均回收率为81.4%～101.8%,相对标准偏差为2.6%～5.0%（n=6）。该方法样品前处理简便、稳定性好、检测限低,适合果蔬中甲醛含量的快速检测。     

Drying and Rehydrating Kinetics of Green and Red Peppers

ABSTRACT: The effects of air temperature, air velocity, and pretreatments (blanching, sulphiting, and sodium chloride dipping) on drying kinetics of green- and red-pepper slices were investigated. Drying experiments were performed in a fluidized bed dryer. In the falling rate period, moisture transfer from peppers was described by applying the unsteady state Fickian diffusion model, and the apparent moisture diffusion coefficients (D_a) were calculated. The effect of temperature on D_a could be interpreted according to Arrhenius law. Drying rate and therefore D_a values were found to be affected by pretreatments. Rehydration rates of dried peppers at 25 and 45 °C were also determined and found to be independent of drying conditions and rehydration temperature. Predrying treatments were found to improve partly the rehydration characteristics of peppers.     

高效液相色谱法测定蜜饯中阿力甜含量的不确定度分析

评定高效液相色谱法测定蜜饯中阿力甜含量的不确定度。依据JJF 1059.1-2012《测量不确定度评定与表示》及新版国标方法GB 5009.263-2016《食品安全国家标准食品中阿斯巴甜和阿力甜的测定》,建立评定阿力甜不确定度的模型,对检测过程中各分量因素进行不确定度的分析评定。本实验蜜饯中阿力甜含量为0.211 7 g/kg,其扩展不确定度为:0.012 8 g/kg,则结果可表示为Y=(0.211 7±0.012 8)g/kg,k=2。通过以上的实验数据和不确定度因素分析,标准溶液引入的不确定度最大,其次是工作曲线,影响最小的是试样。因此需要严格把控标准溶液配制引起的误差,从而可以降低检测的误差,尽量降低不确定度,提高检验检测结果的准确性。     

高效液相色谱法测定水果中吡虫啉农药残留量

建立高效液相色谱法测定水果中的吡虫啉残留量的检测方法。采用改进的QuEChERS方法,乙腈匀浆提取,提取液加C18和PSA填料净化,液相色谱法检测。结果表明：方法的定量检测限为0.05mg/kg,标准曲线线性相关系数0.9988;当添加水平在0.05～0.20mg/kg范围内时,回收率均可在92%～102%之间,相对标准偏差在5%～11%之间。本方法是一种快速、准确、灵敏度高的同时检测水果中吡虫啉残留的检测方法。