不同晚熟柑橘中酚类物质的含量检测及分析

采用超高效液相色谱(ultra-performance liquid chromatography,UPLC)对9种晚熟柑橘(沃柑、春见、大雅柑、不知火、默科特、红肉脐橙、伦晚脐橙、红翠2号和塔罗科血橙)中的主要酚类物质(13种类黄酮和7种酚酸)进行测定,分析比较不同品种柑橘果皮、果肉和果汁(柑橘原汁)中酚类物质种类和含量的差异。结果表明:9个柑橘品种的果皮、果肉、果汁中,类黄酮均以橙皮苷为主,酚酸以阿魏酸为主,且果皮中多甲氧基黄酮含量丰富。在9个柑橘品种果汁中,春见的橙皮苷、咖啡酸含量最高。果肉中,沃柑中阿魏酸、咖啡酸、芥子酸含量最高,塔罗科血橙的橙皮苷、对香豆酸含量最高。果皮中,默科特的芸香柚皮苷、川皮苷、阿魏酸含量最高。杂柑果皮中咖啡酸、阿魏酸及川皮苷含量高于橙类。晚熟柑橘含有丰富的酚类物质,并呈现显著的多样性。     

宽皮柑橘浮皮时脱落酸积累变化及其代谢基因表达特征

采后柑橘果皮大量积累脱落酸(abscisic acid,ABA),且ABA生物合成主要通过类胡萝卜素合成途径.为探究宽皮柑橘浮皮发生过程中ABA含量变化及其代谢基因表达特征,本研究以'克里曼丁'和'椪柑'为试材,利用高效液相色谱-串联质谱和实时荧光定量聚合酶链式反应技术分析18～20℃贮藏30 d后浮皮果实果皮和正常果...     

超高效液相色谱法同时测定柑橘中11种类黄酮物质

通过正交试验优化样品前处理条件,建立超高效液相色谱快速检测柑橘中11种类黄酮物质的方法。以甲醇-乙酸溶液为流动相,梯度洗脱,8种黄烷酮和3种多甲氧基黄酮11min内完全基线分离(检测波长283nm和330nm)。方法检出限为0.005～0.02mg/kg(RSN=3),线性方程的相关系数均达到0.9993以上。果皮和果汁的回收率分别为94.6%～100.2%,94.5%～101.8%;相对标准偏差(n=6)分别为1.1%～3.7%,0.9%～3.9%。该方法快速、高效、低成本、环境友好、结果准确可靠,能满足柑橘中类黄酮化合物的检测要求。     

不同品种柑橘皮中黄酮化合物含量及抗氧化性分析

比较了9个柑橘品种的柑橘皮总黄酮含量及黄酮成分,并对其清除DPPH自由基的能力和对铁离子的还原力进行了评价。结果表明:几乎所有品种间柑橘皮总黄酮含量及黄酮成分都存在显著差异(P<0.05);总黄酮含量最高和最低的品种分别为南丰橘和福建蜜柑,其总黄酮含量分别为9.68,5.28 mg/g;福建蜜柑中柚皮苷的含量较多,江西柳橙、江西脐橙、南方蜜橘和江西蜜柑中橙皮苷的含量较多。9个品种柑橘皮总黄酮含量与其还原力和清除DPPH自由基的能力之间线性无关,即总黄酮含量高的品种其抗氧化水平不一定高。     

柑橘果肉、果皮中酚类物质含量差异性研究

采用高效液相色谱法(high performance liquid chromatographic,HPLC)对8种橙类和杂柑中10种酚类物质含量进行测定,探讨不同柑橘品种果肉和果皮中酚类物质种类和含量的差异,分析其规律。结果表明,10种物质能在55 min内分离,线性范围为0.25~200 mg/L,相关系数达0.999 1~1,精密度(RSD≤1.90%)、重复性(RSD≤3.52%)和稳定性(RSD≤4.22%)较好,平均回收率为90.26%~118.85%(RSD为0.96%~3.01%),表明方法的准确度较高。在橙类和杂柑中,橙类果皮中芥子酸含量显著高于杂柑,杂柑果皮中芦丁含量显著高于橙类;果肉中酚类物质含量低于果皮;果实中酚酸以咖啡酸和绿原酸为主,类黄酮以芦丁和柚皮苷为主;在8个柑橘品种果肉中,金诺的阿魏酸、没食子酸和芦丁含量最高。在8个柑橘品种果皮中,口之津32号的咖啡酸、阿魏酸、对羟基苯甲酸含量最高,沃柑的新橙皮苷、柚皮苷、没食子酸和绿原酸含量最高。     

柑橘皮中川陈皮素超声提取工艺及含量分析

以甲醇为提取溶剂,采用超声波提取柑橘皮中川陈皮素,并用高效液相色谱进行分析,结合单因素和正交实验对超声波提取柑橘皮中川陈皮素的提取工艺进行优化,探讨不同因素对柑橘皮中川陈皮素提取含量的影响。结果表明,最佳提取工艺条件为:90%甲醇、料液比1∶50(W/V)、提取温度50℃、提取时间60min。用优化后的提取条件进行加标回收实验,回收率为90.5%,并用于几样柑橘皮中川陈皮素含量测定。结果表明,精品橙皮中川陈皮素的含量最高。     

柑橘皮中川陈皮素超声提取工艺及含量分析

以甲醇为提取溶剂,采用超声波提取柑橘皮中川陈皮素,并用高效液相色谱进行分析,结合单因素和正交实验对超声波提取柑橘皮中川陈皮素的提取工艺进行优化,探讨不同因素对柑橘皮中川陈皮素提取含量的影响。结果表明,最佳提取工艺条件为:90%甲醇、料液比1∶50(W/V)、提取温度50℃、提取时间60min。用优化后的提取条件进行加标回收实验,回收率为90.5%,并用于几样柑橘皮中川陈皮素含量测定。结果表明,精品橙皮中川陈皮素的含量最高。      

柑橘皮渣发酵-青贮饲料中有机酸的 RP-HPLC 测定

提出了一种利用反相高效液相色谱法同时测定柑橘皮渣发酵-青贮饲料中的6种有机酸的方法。水浴加热萃取法提取样品中的有机酸,采用Welch Materials XB-C18色谱柱（4.6 mm×250 mm,5 μm）,检测波长为214 nm,流动相为0.05 mol/L磷酸二氢钾（pH 2.70）和甲醇（体积比为97：3）,流速为0.80 mL/min,柱温为20 ℃,进样量为20 μL。在此条件下,6种有机酸在20 min内分离良好,各有机酸的回收率在94.96-103.43%,6种有机酸在各自线性范围内线性关系良好,相关系数均大于0.99,相对标准偏差都小于3%,最低检出限在0.53-2.51 mg/L范围。应用本方法测出的样品中草酸、甲酸、乳酸、乙酸、柠檬酸、丙酸含量分别为：0.84、3.69、51.13、20.61、1.76、1.06 mg/g。该方法具有样品处理简单、分析时间短、回收率好、精密度高、相对标准偏差低等优点,可用于柑橘皮渣发酵-青贮饲料中有机酸的检测。     

植物食品中类胡萝卜素的高压液相色谱检测

本文论述了一种在各国的许多实验室中被广泛采用的应用高压液相色谱定性、定量检测植物食品中的类胡萝卜素的方法。色谱的固定相为反相C18柱,流动相A为乙腈和水(9:1),流动相B为乙酸乙酯。洗脱条件为二元线型梯度。梯度的起点为100％的流动相A,终点为100％的流动相B。洗脱时间为20—25分钟。高压液相色谱配备二极管阵列检测器(PDA)是检测类胡萝卜素的理想设备组合。该方法可同步收集各类胡萝卜素组分的色谱及光谱数据,并据此对其进行定性和定量的分析。该方法最突出的优点是应用范围广、易操作、重复性好,因此被认为是一种检测植物食品中类胡萝卜素的“标准”方法。     

三个中国主栽宽皮柑橘品种制汁品质评价

该文研究3种主栽宽皮柑橘制汁品质,评价其制汁特性。通过测定3种宽皮柑橘主要理化指标、营养成分及香气物质,并采用主成分分析进行比较和区分。结果表明,南丰蜜桔具有高糖低酸的特性,椪柑则为高酸低糖。温州蜜柑光学特性L~*、a~*和b~*值较其他2个品种高出2.54～6.06,其色泽属性最佳。温州蜜柑和南丰蜜桔中活性成分含量均高于椪柑,其中温州蜜柑中总酚含量最高达43.78 mg/100 mL。椪柑的柠檬苦素含量为0.59 mg/L,显著高于其他2个品种,表现为苦味严重,而南丰蜜桔几乎不表现苦味特征。椪柑的风味品质最好,香气物质总含量高达673.74μg/g,南丰蜜桔最差,含量仅为281.37μg/g。因此,温州蜜柑制汁特性最佳,但其他因素如气候、土壤条件等也会对柑橘汁品质产生显著影响。     

Study of major aromatic compounds in port wines from carotenoid degradation

The carotenoids degradation and the formation of volatiles were examined by simulating Port wine aging. A two year old red Port wine was saturated with oxygen, supplemented with lutein and β-carotene and kept at 60 °C during 87 h. A similar study was performed in a model wine solution. Results showed that the percentage decrease in lutein levels was, respectively, 79% and 95%, in the wine model solution and in the Port wine, and 55% and 10% for β-carotene, indicating that lutein was more sensitive to degradation than β-carotene. Two other unknown degradation carotenoid compounds were identified by HPLC/DAD (reverse phase λ_max: 422; 445; 475 and 422; 445; 472) in the lutein supplemented wine. Levels of β-ionone and β-cyclocitral increased (2.5 times) in both, wine and wine model solution, supplemented with β-carotene. Along with these compounds, the same behaviour was observed in β-damascenone in the supplemented lutein wine and wine model solution. New insights were provided into the understanding of aroma modifications occurring during Port wine aging. The relationship between carotenoid molecules (β-carotene and lutein) and some volatiles has also been provided.     

Antioxidant capacity and major phenolic compounds of spices commonly consumed in China

The antioxidant capacity, total phenolic content, and major phenolic compounds of a total of 19 commonly consumed spices in China were systematically investigated. Ultra performance liquid chromatography (UPLC) coupled with photodiode array detector (PDA) was used to identify and quantify the phenolic compounds in the spice extracts. Galangal exhibited the highest antioxidant capacity, associated with the highest total phenolic content. Furthermore, galangin was identified as the principal phenolic component and the main contributor to the highest antioxidant capacity of galangal. Spices in the family Rutaceae and Lauraceae possessed very high antioxidant capacity and high levels of phenolics. Generally, chlorogenic acid and rutin were identified as the dominant phenolic compounds in the spice extracts. This study might provide useful information not only for human health, but also for screening new economic natural antioxidants that could be used in foods.     

Comparative study of aromatic compounds in young red wines from cabernet sauvignon, cabernet franc, and cabernet gernischet varieties in China

ABSTRACT:  The aromatic composition and key odorants of young red wines produced from Cabernet Sauvignon, Cabernet Franc, and Cabernet Gernischet wines were compared and the reasons for the difference in their aromatic compounds were discussed. Forty-three odorants were detected in Cabernet Sauvignon and Cabernet Franc wines compared to 50 in Cabernet Gernischet wine. Quantitatively, acids formed the most abundant group in the aromatic components of the 3 wines, followed by alcohols and esters. Compared to Cabernet Sauvignon and Cabernet Franc wines, the profiles of alcohols and esters for Cabernet Gernischet wine were more diverse. Monoterpenes, namely, 4-terpinenol, citronellol, and nerol, were found solely in Cabernet Gernischet wine. Only 10 compounds, namely, ethyl octanoate, ethyl hexanoate, isoamyl acetate, ethyl butyrate, β-damascenone, ethyl decanoate, isoamyl alcohol, acetic acid, octanoic acid, and phenylethyl acetate, were always present in the 3 wines at concentrations higher than their threshold values. However, ethyl octanoate, ethyl hexanoate, and isoamyl acetate were found to jointly contribute to 97%, 98.9%, and 99% of the global aroma of Cabernet Sauvignon, Cabernet Franc, and Cabernet Gernischet wines, respectively. This result showed that the aroma indistinguishableness of the 3 wines was mainly due to the dominance of the fruity notes exerted by the ethyl esters and, to a lesser extent, to the contribution of varietal aromatic compounds to the global aroma of the wines.     

Vitamin E and carotenoid accumulation during kernel development in two varieties of Castanea henryi

Chestnut is rich in vitamin E and carotenoids, and it is popularly consumed in many areas owing to its health benefits. This study aimed at investigating the metabolic regulation of vitamin E and carotenoids during kernel development of Castanea henryi (‘Jinzhui’ (YS) and ‘Baiyan No.1’ (WS)). Along with the increasing growth time of chestnut kernels, vitamin E contents showed a sustained increase, and γ-tocopherol was always the most abundant composition. 4-hydroxyphenyl-pruvate dioxygenase and geranylgeranyl diphosphate synthase were theorised to regulate tocotrienol biosynthesis in WS, but there was no such relationship in YS. Lutein dominated the total carotenoid content changes with a decrease at the final growth stage. Moreover, zeaxanthin and β-carotene had an overall downward trend and may be regulated by gene for 1-deoxy-D-xylulose-5-phosphate reductase. The results provide a theoretical basis for harvesting control and cultivation management of C. henryi based on nutrition enhancement.     

Polyphenol compounds in artichoke plant tissues and varieties

Polyphenol compounds, particularly caffeoylquinic acids and flavonoids, were measured in different tissues and developmental stages of 6 artichoke varietal types diffused in the Mediterranean region. Flower heads were subdivided into external, intermediate, internal bracts, and receptacle, while leaves were collected at the vegetative and productive stages. The main polyphenols detected were chlorogenic acid, cynarin, luteolin 7-O-rutinoside, and luteolin 7-O-glucoside. "Violet de Provence" artichoke proved to retain the highest content of total phenols. Single polyphenols accumulated preferentially in specific parts of capitula. In leaves, most polyphenols were detected in the productive stage of the plant. Altogether, results provide useful indications for the promotion of artichoke as nutraceutical food and for the extraction of health-promoting substances in particular tissues/stages of the artichoke plant. PRACTICAL APPLICATION: We describe the content of phenolic compounds in various artichoke tissues, developmental stages, and varieties. Results indicate that artichoke leaves represent an important source of these health-promoting compounds, also useful for phytopharmaceutical applications. A wider utilization of specific artichoke types should be strongly encouraged not only as a food for the fresh market, as they are now used, but also for the pharmaceutical industry, since the content of phenolic compounds is abundant both in the heads and in the leaves.     

Identification of aroma‐active compounds in fresh and stored ‘Mor’ mandarins

In this study, gas chromatography–olfactometry (GC‐O) (sniffing) combined with gas chromatography–mass spectrometry (GC‐MS) analysis was applied to identify volatile aroma‐active compounds in homogenised segments of fresh and stored ‘Mor’ mandarins. The GC‐O nasal impact frequency method was used to identify Twenty‐three aroma‐active compounds, of which seventeen odorants were identified by GC‐MS. The aroma of fresh ‘Mor’ mandarins derived from a mixture of eleven odorants that contribute ‘green’ [(E)‐3‐hexenol and hexanal], ‘fresh’ [(E)‐carveol], ‘fruity’ (ethyl 2‐methylbutanoate), ‘citrus’ (limonene), ‘floral’ (linalool), ‘musty’ (β‐myrecene and γ‐terpinene), ‘potato’ (α‐terpinene), ‘mushroom’ (unknown 2) and ‘cabbage’ (α‐cubebene) odours. During postharvest, storage losses were observed in ‘green’ [(E)‐3‐hexenol] and ‘fresh’ [(E)‐carveol] odours, accompanied by increases in ‘fruity’ (ethyl propanoate) and several unpleasant aromas, such as ‘alcohol’ (ethanol), ‘musty’ [α‐pinene, (E)‐2‐nonenal and 1‐terpinen‐4‐ol] and ‘fatty’ (octyl acetate and δ‐cadinene) odours, all of which possibly account for the observed decrease in sensory acceptability after harvest.     

SPME-GC-MS detection of volatile compounds in apricot varieties

Aroma compounds of the eight Malatya apricot cultivars, six cultivars grown in the same breeding conditions from different locations and one hybrid cultivar were determined using SPME-GC-MS technique. In general, total concentration (sum of identified and unidentified peaks) of aroma compounds in Malatya apricot cultivars were lower than those others. Total concentration of aroma compounds were found to be in the range of 514 and 6232 μg/kg fresh weight. The main volatiles of apricot cultivars were aldehydes, alcohols, acetates, esters, terpenes and acids. Among these compounds; ethanol, hexanal, hexyl acetate, (Z)-3-hexenyl acetate, (E)-2-hexenyl acetate, 1-hexanol, (Z)-3-hexenol and (E)-2-hexen-1-ol, were present in all cultivars studied at certain levels.     

不同酿酒高粱酚类物质含量测定及抗氧化活性比较

以6种酿酒高粱籽粒为研究对象,分别比较其游离态与结合态总酚、总黄酮、酚酸物质种类及含量,并对其抗氧化活性进行 分析。 结果表明,不同酿酒高粱品种游离态总酚、总黄酮;结合态总酚、总黄酮含量分别在135.47～274.38 mgGAE/100 g、94.60～ 148.31 mg/100 g;618.27～1 383.17 mgGAE/100 g、123.06～434.84 mg/100 g。 酿酒高粱籽粒中游离态酚酸以阿魏酸、丁香酸与没食 子酸为主,平均含量分别为611.19 μg/g、380.66 μg/g、359.34 μg/g;结合态酚酸以阿魏酸、丁香酸为主,平均含量为1 608.33 μg/g、 376.78 μg/g。 酿酒高粱籽粒中游离态与结合态总酚ABTS抗氧化能力值分别占总ABTS能力值14.6%与85.4%;酿酒高粱籽粒中游离 态与结合态总酚FRAP抗氧化能力值占总FRAP能力值14.3%与85.7%。 酿酒高粱籽粒具有丰富的酚类物质,良好的抗氧化活性,且品 种间有显著性的差异（P＜0.05）。     

不同麦芽品种的脂质氧化性能差异分析

研究了不同麦芽品种的脂质氧化相关指标分布特点及性能差异,为优选麦芽,提高啤酒新鲜度提供依据。基于溶液模型,研究确定了单酚物质阿魏酸、儿茶酸、咖啡酸能抑制脂肪氧合酶(lipoxygenase,LOX)的催化作用,金属离子能促进LOX酶作用;随后测定啤酒厂6种常用麦芽品种的11项脂质氧化指标,方差分析显示,不同麦芽品种的反-2-壬烯醛(trans-2-nonenal,T2N)、壬烯醛潜力(nonenal potential,NP)、单酚、金属离子之间存在显著差异;判别分析显示,加麦Copeland、加麦Metcalfe和甘啤在脂质氧化指标上较接近;基于主成分分析,建立脂质氧化综合评价指标,优选出脂质氧化程度低的麦芽。