2种火龙果的果肉果皮成分及其抗氧化活性对比

通过水提法探讨红肉火龙果和白肉火龙果的果皮和果肉四者中黄酮、多酚、总花色苷含量的区别。通过测定红肉火龙果中果皮和果肉,白肉火龙果中果皮和果肉中清除DPPH自由基的能力、ABTS自由基清除能力、FRAP法还原能力三者不同原理来综合评价其体外抗氧化能力。结果表明,果皮中多酚、黄酮、花色苷的含量远远大于果肉中的含量;DPPH自由基清除法和FRAP法显示抗氧化活性由强到弱的顺序为:白皮红皮红肉白肉,而ABTS自由基清除率法则为红皮白皮红肉白肉,表明火龙果果皮的抗氧化活性大于果肉,而红肉的抗氧化能力强于白肉。研究结果为火龙果的不同品种和不同部位的研究奠定基础,为火龙果果皮和果肉的深度开发利用奠定理论依据。     

萝卜籽油的营养特性及制取工艺研究现状

萝卜籽属药食同源,富含油脂。萝卜籽油不饱和脂肪酸含量较高,营养较为丰富,因富含莱菔素具有抗菌消炎和抗癌等功效。综述了萝卜籽油的成分、脂肪酸组成及营养功能特性,并对其研究现状进行了介绍,以期为萝卜籽油的开发和生产提供参考。     

不同生长时长对桑植萝卜综合品质的影响

桑植萝卜是国家地理标志产品。本文以3个不同生长时长的桑植萝卜为研究对象,基于其感官特性、营养和功能成分等指标结合主成分分析评价桑植萝卜的综合品质。结果表明,桑植萝卜II期(生长期58 d)的综合品质最优。     

洋葱的抗氧化能力及发酵对其的影响

利用二苯代苦味酰基自由基(DPPH)清除试验,抑制亚油酸氧化试验和还原能力试验评价白皮洋葱、红皮洋葱、黄皮洋葱的抗氧化能力.此外对红皮洋葱加入盐糖进行发酵,检测其DPPH清除能力的变化.结果表明,不同洋葱抗氧化能力从大到小依次为红皮洋葱＞黄皮洋葱＞白皮洋葱,发酵可以使红皮洋葱抗氧化能力提高.     

催陈方法对白肉枇杷果酒品质的影响

研究了超声、微波和冷热交替催陈工艺处理对白肉枇杷果酒品质形成的影响,结果显示,不同催陈处理枇杷果酒总酸略降及色度增加,感官评价显示冷热交替催陈处理优于超声催陈和微波催陈;处理后果酒香气物质检出种类减少,未检出成分占比增加,相对含量最高的是醇类和酯类,冷热交替、超声和微波催陈处理分别占比79.8%,78.3%,88.97%,均低于原酒的91.24%;催陈处理使其他香气成分占比增加,有利于提升果酒总体香气。醇类、醛类、酸类和酯类是影响果酒品质的主要成分,进一步分析显示香气品质得分依次为微波催陈冷热交替催陈超声催陈。对酒品质的评价应综合考虑感官评价、主成分分析和未检出成分测定结果,并由此得到冷热交替催陈处理白肉枇杷果酒较好。     

基因型与储藏时间对小麦粉白度的影响

分析基因型差异与不同储藏时间对小麦粉白度的影响,结果表明,基因型对面粉白度的影响极显著;红皮小麦粉白度高于白皮小麦,但红皮和白皮小麦中都有白度较高和较低的品种;不同品种小麦粉白度随着制粉后储藏时间的延长逐渐增长,面粉白度变化存在三种类型:(1)短期上升后稳定;(2)短期上升后下降;(3)持续上升。不同类型品种面粉达到最高白度其适宜储藏时期有一定范围。面粉白度变化趋势因籽粒蛋白质含量高低不同而存在差异,不同专用类型小麦品种加工的面粉白度表现为强筋小麦<中筋小麦<弱筋小麦。     

基于氨基酸含量的玉米品种品质综合评价

目的：研究基于氨基酸含量的不同玉米品种的品质差异。方法：以16个新玉系列玉米品种为研究对象,测定玉米籽粒中氨基酸含量,并以玉米籽粒中含有的16种氨基酸含量作为评价指标,进行主成分分析,并对玉米品种进行聚类分析。结果：玉米品种对16种氨基酸含量的影响顺序为Met＞His＞Tyr＞Lys＞Pro＞Thr＞Leu＞Glu＞ Ser＞Phe＞Val＞Asp＞Ala＞Ile＞Gly＞Arg;主成分分析可提取出2个主成分,其累计方差贡献率达90.227%;Ala、Ser、Glu、Leu、Asp、Phe和Met可作为不同玉米品种品质综合评价指标;基于氨基酸含量的品质优劣顺序,可将16个玉米品种划分为三大类。结论：新玉54号和新玉65号两个品种综合品质较好,新玉87号和新玉13号2个品种综合品质较差。     

基于熵权TOPSIS法的不同品种甜樱桃营养品质综合评价

为探究不同品种甜樱桃综合营养品质,选用烟台市栽培的10个优良樱桃品种：红灯、美早、拉宾斯、美国一号、萨米脱、布鲁克斯、钻石之光、黄蜜、先锋及雷尼为试验材料,测定其理化性质及总酚、总黄酮、总花青素、原花青素、维生素C、β-胡萝卜素含量,并建立熵权TOPSIS模型,对不同品种甜樱桃的综合营养品质进行评价。结果表明：不同品种甜樱桃的理化性质差异较大,对其营养品质进行分析可得美早的总酚、总黄酮、总花青素及维生素C含量最高,黄蜜的β-胡萝卜素含量最高。此外,抗氧化能力分析可得美早的DPPH自由基清除能力及铁离子还原力最强（分别为88.6%、388.6 mg AAE/100 g）。对不同品种甜樱桃的综合营养品质评价由高到低排序为美早＞拉宾斯＞红灯＞布鲁克斯＞萨米脱＞钻石之光＞雷尼＞先锋＞美国一号＞黄蜜。综上,美早的综合营养价值最高,抗氧化能力最强,是较为优良的栽培品种。     

红、白肉主要营养素受高温加工的影响

为探索红、白肉营养素受高温的影响,主要研究了3种高温加工(煎制、炸制、烤制)处理后红、白肉(猪肉、鸡鸭肉)营养素的变化。结果表明,经加工后3种肉水分含量均显著降低,烤制工艺水分含量最低(p 0. 05);脂肪含量在炸制处理时急剧增大(p 0. 01);加工后脂肪酸含量呈不同程度的增高;加工后蛋白质含量均极显著增大(p 0. 01),烤制时含量最高;氨基酸含量受加工工艺影响较显著(p 0. 05),但氨基酸组成无明显变化,烤制对氨基酸的影响较大。对比红白肉发现,对照组与加工后的猪肉水分含量均稍低于鸡鸭肉,而脂肪含量均高于鸡鸭肉;对于蛋白质,除煎制组和炸制4 min外,其他处理组猪肉蛋白质含量均高于鸡鸭肉。这些研究结果为提高红、白肉高温加工肉制品的营养品质以及为消费者更加科学地选择高温加工工艺提供了理论依据和现实指导。     

肃南牦牛不同部位肉品质评价研究

目的 综合评价肃南牦牛不同部位肉品质,为合理开发利用肃南牦牛肉及其产业化,提高经济效益以及建立牦牛分割肉等级评价体系提供科学依据。方法 本试验选择3岁龄雄性肃南牦牛米龙、外脊、上脑、牛腩四个部位肉样,通过蛋白质、脂肪等营养成分、钙、铁等7种矿物质元素以及氨基酸组成与含量,综合评价牦牛肉的品质特性。结果 从营养价值的角度上,不同部位牦牛肉中蛋白质含量无差异(P>0.05);米龙部位的粗脂肪含量显著高于其它三个部位(P<0.05);牦牛肉富含矿物质元素,米龙部位Fe、Zn、K的含量显著高于其他三个部位,上脑部位Na、Ca、Mg的含量显著高于其他三个部位(P<0.05)。四个部位牦牛肉中必需氨基酸与总氨基酸的比值(EAA/TAA)分别为40.50%、40.40%、40.03%和40.70%,均在40%以上,属于优质蛋白质。结合主成分分析和典型判别分析,很好的实现了四个不同部位肉品质的区分。结论 肃南牦牛肉品质较优,富含丰富的蛋白质和矿物质元素且蛋白质品质较好。综合评价来讲,米龙部位的肉品质及风味较其他部位好。     

Influence of seed on thiocyanate content of radishes

The thiocyanate content was studied in seed and marketable root of 5 white and 8 red cultivars of radishes (Raphanus sativus L.) grown under greenhouse conditions. The SCN^? content in seeds prior to planting was negatively correlated with the SCN^? content in marketable roots of white cultivars. On the contrary, there was a corresponding positive correlation for red cultivars. Although larger seeds resulted in larger radishes, there was no difference in SCN^? content in root of plants grown from different seed sizes. The evidence suggests a genotypic association between colour type and root/seed thiocyanate ratio of radish cultivars.     

Separation and purification of sulforaphene from radish seeds using macroporous resin and preparative high-performance liquid chromatography

This present study described a rapid and cost-effective method for the separation and purification of natural sulforaphene from radish seeds by SP-700 macroporous resin and preparative high-performance liquid chromatography (HPLC). Sulforaphene with high purity and recovery was obtained by preparative HPLC with a C18 column and 30% methanol in ultra-pure water as the mobile phase. 12.5 kg of radish seeds, which contained 87.5 g of sulforaphene, produced 117.5 g of sulforaphene-rich extract of 65.8% sulforaphene after primary separation by SP-700 macroporous resin. 5.9 g of 96.5% sulforaphene was obtained from 9.5 g of the sulforaphene-rich extract after purification by preparative HPLC. The purified compound was assessed by analytical HPLC and characterised by ESI/MS, ¹H NMR and ¹³C NMR. Standard curve was developed using the purified sulforaphene to allow quantification of sulforaphene in the extracts of radish seeds by analytical HPLC.     

Raphasatin is a more potent inducer of the detoxification enzymes than its degradation products

Abstract: The biological activity of cruciferous vegetables is hypothesized to be due to the metabolites of a class of phytochemicals called glucosinolates. The chemical properties of these metabolites, including isothiocyanates, determine the biological activity of these compounds and thus their effects on human health. The 2 primary radish (Raphanus sativus L.) glucosinolates, glucoraphasatin, and glucoraphenin, were isolated using solid phase extraction followed by preparative HPLC purification. In an aqueous environment, 77.6% of the maximum amount of sulforaphene produced by the metabolism of glucoraphenin was present after 24 h. Under the same conditions raphasatin, the isothiocyanate metabolite of glucoraphasatin and the oxidized counterpart of sulforaphene, was highly unstable with a half‐life of less than 30 min and no raphasatin was detectable after 24 h. In HepG2 cells, raphasatin‐induced quinone reductase activity and the RNA expression of several phase 1 and 2 detoxification enzymes by a significantly greater amount than the degradation products of raphasatin. Raphasatin, but not its degradation products, activated the antioxidant response element (ARE) in a stably‐transfected reporter cell line. Mice fed a diet consisting of 20% freeze dried radishes for 2 wk had significantly higher liver expression of cytochrome P450 (CYP) 1A1, 1A2, quinone reductase, microsomal epoxide hydrolase, and glutathione S‐transferase α2 than mice fed a nutritionally‐matched control diet. Practical Application: Glucoraphasatin, the primary glucosinolate in radishes, is metabolized into an isothiocyanate (raphasatin) that has biological activity but is also unstable in an aqueous environment. Despite the instability of raphasatin, dietary exposure to radishes produced significant induction of detoxification enzymes. Understanding the chemical properties of raphasatin, both in terms of biological activity and instability, could help develop processing methods to retain the most activity from radishes, glucoraphasatin, and raphasatin.     

Enhancing stability and bioavailability of sulforaphene in radish seed extracts using nanoemulsion made with high oleic sunflower oil

Food Science and Biotechnology - The effect of nanoemulsions on the stability and bioavailability of sulforaphene (SFEN) in radish seed extract (RSE) was investigated. Four types of oil were used...     

不同酵母菌发酵对猕猴桃果酒品质的影响

该研究以四川省苍溪县地区所产的红心猕猴桃为原料,在同一实验条件（带皮破壁）下经7种不同酵母菌（AU、BA、BV、EC、FR、MA、RW）发酵得到不同猕猴桃果酒,利用色度仪、电子鼻、电子舌等对猕猴桃果酒的色泽、风味、滋味等进行分析;使用主成分分析法（PCA）和非加权组平均法（UPGMA）评价猕猴桃果酒的整体品质。结果表明,不同酵母菌发酵制得的猕猴桃果酒整体品质存在显著性差异（P＜0.05）。酵母菌AU、MA发酵的猕猴桃果酒具有良好的色泽,酵母菌BV发酵的猕猴桃果酒在气味和滋味上表现较为优异,可为猕猴桃果酒酵母菌的选择提供参考。     

Seasonal climate effects on root colour and compounds of red radish

‘Nevadar’ radishes were grown throughout the year. Climate parameters (mean temperature, mean irradiation) and quality characteristics of radishes fulfilling consumer quality requirements, such as root colour, glucosinolates, monosaccharides and pectic substances, were determined. The quality characteristics strongly differed depending on the seasonal climate conditions. The seasonal dependence ranged from a slight climate influence (alkenyl glucosinolates r² = 0.23), over a moderate climate effect (indolyl glucosinolates r² = 0.40, glucose r² = 0.50) up to a strongly distinctive climate influence (hue angle r² = 0.77, chroma r² = 0.72, fructose r² = 0.81, pectic substances r² = 0.99). Therefore, according to consumer‐oriented quality production of radish, the temperature and irradiation influence should be taken into account in the production process. Recommendations for quality production of radish will be the selection of bright red cultivars marked by a high photosynthetic capacity (yield > 0.80 mV) at relatively low mean irradiation intensities (50–100 µmol m² s^?1) and lower mean temperatures (11–13 °C). Thus sufficient photochemical energy can be provided for the synthesis of quality‐determining compounds. For the production of bioactive radishes showing particularly relatively high contents of indolyl glucosinolates, cultivation should be carried out in spring and autumn. In summer cultivation, consumer preferences in taste can particularly be satisfied with the desired contents of alkenyl glucosinolates and monosaccharides. © 2002 Society of Chemical Industry     

白茶散茶与茶饼在色泽、滋味及香气组分上的差异研究

为探明压饼工艺对白茶品质的影响,本文以白牡丹散茶为原料制成白牡丹茶饼,比较了压饼工艺前后白茶散茶与茶饼之间在干茶色泽、滋味及香气组分上的差异。结果表明,散茶色泽鲜绿、滋味浓、香气以嫩香为主,而茶饼色泽黄、滋味浓醇、香气以果香与甜香为主。与散茶相比,茶饼色泽的红绿度(a*)极显著(p<0.01)增加,干茶色泽变红;总叶绿素、叶绿素a和b含量均极显著(p<0.01)降低;水浸出物、茶多酚、黄酮与"茶三素"含量显著(p<0.05)降低,而氨基酸、可溶性糖含量显著(p<0.05)提高,引起酚氨比极显著(p<0.01)降低。与散茶相比,茶饼中醇类香气总量和香叶醇组分相对含量降低9%左右,而芳樟醇氧化物、烯类、酮类、酯类和杂氧化合物香气平均相对总量分别增加1.86%、1.89%、1.87%、3.42%和0.83%;香气组分主成分分析得出,茶饼香气质量综合得分比散茶高4~7分。     

萝卜花色苷的结构研究

红皮白心萝卜的色素提取物经大孔树脂XAD-7HP和葡聚糖凝胶Sephadex LH-20纯化后,结合半制备色谱制备花色苷单体,最后通过LC-MSn和NMR技术手段对萝卜花色苷单体的结构进行分析。通过LC-MSn鉴定出萝卜皮中主要存在四种主要的花色苷,都是以天竺葵色素为苷元,带一个单糖和一个二糖的花色苷衍生物,即以天竺葵-3-槐糖苷-5-葡糖苷为基本结构,带有一个或是两个酰基化的基团,如丙二酸、阿魏酸或香豆酸。经由1H NMR方法,其中三种花色苷的具体结构鉴定为:3-[6-(对香豆酰)-L-葡萄苷(2→1)-葡糖苷]-5-D-吡喃葡糖苷天竺葵素、3-[6-(阿魏酰)-L-葡萄苷(2→1)-葡糖苷]-5-D-吡喃葡糖苷天竺葵素、3-[6-(对香豆酰)-L-葡萄苷(2→1)-葡糖苷]-5-[(6-丙二酰)-D-吡喃葡糖苷]天竺葵素。通过质谱信息和文献报道,第四种花色苷的结构应为3-[6-(阿魏酰)-L-葡糖苷(2→1)-葡糖苷]-5[-(6-丙二酰)-D-吡喃葡糖苷]天竺葵素。     

杂粮复合豆沙营养及功能品质评价

以薏米、苦荞分别与红小豆、红芸豆制成杂粮复合豆沙,检测其蛋白质、氨基酸、淀粉等宏量营养素以及黄酮、多酚、花青素等微量活性成分含量,并对营养品质及功能成分进行综合评价。结果表明,与红小豆沙和红芸豆沙相比,薏米或苦荞复合豆沙的蛋白质、总淀粉、慢消化淀粉、抗性淀粉、氨基酸总量、必需氨基酸、黄酮、多酚、花青素等营养功能成分含量均显著增加(P0.05)。基于主要营养、功能物质含量,采用主成分分析(PCA),7个豆沙样品营养价值由高到低依次为:苦荞红小豆沙薏米红小豆沙苦荞红芸豆沙薏米红芸豆沙红小豆沙红小豆沙(市售)红芸豆沙,这表明杂粮复合豆沙具有更高的营养功能品质。