基于PLSR分析樱桃酒呈味物质与感官属性之间的相关性

以6种不同厂家生产的樱桃酒为研究对象,进行感官评价并利用高效液相色谱法鉴定出樱桃酒样品的33种特征呈味物质,并进行了主成分分析和聚类分析。结果显示,相同产地的樱桃酒聚集在一起成一类,不同产地的樱桃酒明显区分开来。通过偏最小二乘法对不同产地樱桃酒中特征呈味物质与感官属性之间的相关性进行研究,结果发现甜味与葡萄糖、蔗糖、果糖呈现出显著正相关;涩味与丝氨酸、苯丙氨酸呈显著正相关;苦味与咖啡酸、谷氨、丝氨酸、甘氨酸、苏氨酸、丙氨酸、缬氨酸、蛋氨酸、苯丙氨酸、异亮氨酸、亮氨酸、赖氨酸呈现显著正相关。     

酚类物质及其化学修饰物抗真菌的构效关系研究

本文选用酚类物质及一系列酚类衍生物共30种为供试药剂,对果蔬采后难控制的三种致腐病原真菌进行药效实验。对药剂的化学结构与抗菌性能关系进行分析,结果表明:(1)邻位、对位多元酚对这三种病原真菌的抑制作用比一元酚作用强,间位多元酚的作用最弱。二元酚作用比对应三元酚强。(2)邻位、对位二元酚中的一个羟基被羧基取代后,其抑菌性能大大减弱。(3)对羟基苯甲酸羧基酯化后,极大地提高了抑菌性能,抑菌性能最强,当酯化烷链的碳原子数超过7个时(碳链长度≥7)其抗菌性能迅速降低。(4)酚乙酰化后,抑菌性能发生变化,间位多元酚乙酰化后,抑菌性能增强,其它酚乙酰化后,抑菌性能均有所下降。     

蓝莓果实多酚和抗氧化研究

利用LC-MS结合标准品对贵州麻江栽培的杰兔、园蓝、奥尼尔、夏普兰、海岸、蓝雨6个品种蓝莓成熟果实酚类物质进行定性分析。利用HPLC定量分析其15种单体花色苷、3种酚酸、3种类黄酮物质含量,利用分光光度计分析其总酚、总花青素、DPPH抗氧化能力。结果表明:6个品种蓝莓成熟果实总花青素、总酚、21种单体酚类物质含量、DPPH抗氧化能力、果实直径和质量差异较大,其中园蓝的总酚、总花青素、10种花色苷和绿原酸含量相对最高,园蓝和蓝雨具有较高的总酚、总花色苷含量,但是其果实直径和质量较小,适宜加工或提取活性成分。     

Simultaneous Determination of Phenolic Acids and Scopoletin in Brandies Using Synchronous Fluorescence Spectrometry Coupled with Partial Least Squares

Brandy, a spirit drink produced from wine (grape), is rich in phenolic acids due to its maturation in wooden barrels. Phenolic acids play a significant role in defining the sensorial characteristics of wines and brandies, and therefore, it is very useful to determine them. Synchronous fluorescence spectra of mixtures containing phenolic acids (gallic, vanillic, syringic and ferulic) and scopoletin have been used for the determination of these compounds by partial least squares (PLS)2. Synchronous fluorescence spectra were collected by simultaneously scanning the excitation and emission monochromator in the excitation wavelength range 200–500 nm, with constant wavelength difference 100 nm between them. The leave-one-out cross-validation method was used to select the optimum number of five PLS2 components (latent variables). The PLS2 model captured for 100 % of variance in the spectral block, and it accounted for 99.34 % of variance in the concentration block. The performance of the model was evaluated by means of root mean square error of cross-validation, root mean square error of prediction and coefficient of determination. The best model was used for the determination of the above-mentioned compounds in brandy samples at concentration levels 2–74 mg L^?1 for phenolic acids and 0.06–0.43 mg L^?1 for scopoletin. The PLS2 results were found to be in good agreement with those obtained by HPLC method.     

基于主成分分析和偏最小二乘法的蒸煮大豆食味品质评价

通过建立主成分分析结合偏最小二乘法(PLS)评价蒸煮大豆食味品质。以黑龙江45个大豆品种的理化指标、浸泡后的吸水率和膨胀率为自变量,以蒸煮后的硬度、咀嚼性和感官评分为因变量,应用偏最小二乘法判别模型中各变量的相关系数和变量投影重要性,筛选影响蒸煮大豆食味品质的主要因素并进行主成分分析。结果表明:通过PLS筛选出大豆钙含量、伴大豆球蛋白(7S球蛋白)、可溶性糖含量和膨胀率对蒸煮后大豆质构特性有主要影响。主成分分析检测得到4个主成分,累计贡献率达73.374%,可较好地反映蒸煮大豆食味品质信息。根据各主成分的贡献率得出蒸煮大豆的硬度、咀嚼性及7S球蛋白、11S/7S、钙含量等为蒸煮大豆食味品质的主要影响因子。利用主成分综合得分模型对不同品种的蒸煮大豆食味品质进行综合评分,筛选出5种适宜蒸煮加工的大豆品种,即:黑农85、合丰55、JD149、绥农42和东农251。     

不同品种梨果实酚类物质和抗氧化性能分析

以我国北方11 个主栽梨品种黄冠、绿宝石、雪梨、鸭梨、丰水、南水、圆黄、黄金、华山、五九香和早酥的果实为试材,分别测定了果皮、果心和果肉中可溶性酚的含量,并对酚类物质进行了高效液相色谱（highperformance liquid chromatography,HPLC）分析。通过分别测定果皮、果肉、果心的乙醇提取液对DPPH自由基和羟自由基的清除能力,对其所含酚类物质的抗氧化性能进行了评价。结果表明：1）梨果心酚类物质含量高于果皮,果肉最低;2）在果心和果皮中均检测出熊果苷、没食子酸、儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸和芦丁8 种酚类物质,而在果肉中检测出熊果苷、没食子酸、绿原酸、表儿茶素和芦丁5 种物质;3）熊果苷、绿原酸和表儿茶素都为果肉和果皮的主要酚类物质,果肉中绿原酸的含量高于熊果苷,果皮则反之,果心所含酚类物质以绿原酸和熊果苷为主,且绿原酸的含量高于熊果苷;4）果皮、果肉、果心不同部位的酚类物质的含量与1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力和羟自由基清除能力间均分别呈显著正相关关系,表明酚类物质与自由基清除能力的关系密切。     

Phenolic Composition and Antioxidant Activities of 11 Celery Cultivars

ABSTRACT:  Eleven cultivars of celery, belonging to 2 species, were collected and analyzed for their phenolic compound composition and antioxidant activities. Major phenolic acids identified in the extracts of these celeries were caffeic acid,  p -coumaric acid, and ferulic acid, while the identified flavonoids were apigenin, luteolin, and kaempferol. The contents of total phenolics were measured using a Folin–Ciocalteu assay and the total antioxidant capacity was estimated by the 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS·⁺) methods. Apigenin was the major flavonoid in these samples and the most abundant phenolic acid was  p- coumaric acid. Many of the investigated cultivars had high levels of phenolics and exhibited high antioxidant capacity. Among these 11 cultivars, Shengjie celery had the highest antioxidant activity whereas Tropica had the lowest. An extremely significant positive correlation between the antioxidant activity and the contents of total flavonoids, total phenolic acids, or total phenolics was observed in this study.     

Chlorogenic Acid and Other Phenolic Compounds in Fourteen Sweet Potato Cultivars

Fourteen cultivars of sweet potatoes were analyzed qualitatively for their phenolic content at harvest and after storage. The phenolic content of the sweet potato cultivars, Centennial, Jasper, Jewel, LO-323, L3-243, L3-151, L4-62, L4-112, L4-131, NC-702, NC-718, NC-719, NC-345, and V₂-237, was assayed. The qualitative examination of the sweet potato phenolics resulted in the separation and identification of four isomers of caffeolyquinic acid. A fifth compound, which exhibited phenolic acid characteristics, was separated but could not be identified.     

Comparison and Chemometric Analysis of the Phenolic Compounds and Organic Acids Composition of Chinese Wines

Characteristics of 106 wines from 5 major grape varieties and 3 typical geographic regions in China were investigated by means of profiling of organic acids and phenolic compounds analysis. An ultra‐performance liquid chromatography method was developed and thus, large number of samples could be determined in a quick and reliable way. The results showed that different origins and varieties were characteristic of various profiles of organic acid and phenolic compounds. In order to investigate possible correlation between organic acids and phenolic compounds content and grape variety and/or geographical origin, analysis of variance and linear discriminant analysis (LDA) were conducted. A satisfactory LDA result for red wines according to geographic origin was obtained, in which the correct classification was 100% and the leave‐one‐out validation accuracy was 90%. The corresponding results of white wines were 91% and 86%, respectively. When LDA was processed, according to grape varieties, the proportionality of successfully classified wines was 96%, while the leave‐one‐out validation accuracy was 94%. The organic acids and phenolic compounds profiles were useful in the classification of Chinese wines according to grape variety and geographic origin.     

偏最小二乘光度法同时测定多组分染料混合物

采用正交设计校正偏最小二乘法（PLS）模型,用偏最小二乘法辅助分光光度法,不经分离,同时测定碱性品红、甲基紫、结晶紫、中性红四组分混合染料,测得四组分混合体系中各组分的平均回收率和RSD分别为100.5%,100.4%,99.5%,100.4%和1.37%,1.12%,1.05%,1.21%.结果表明,该法测定速度快,结果准确,为不经分离直接测定多组分染料混合物提供了新途经.     

Phenolic Composition and Browning Susceptibility of Various Apple Cultivars at Maturity

Phenolic compounds and polyphenol oxidase (PPO) activity in the fruits of 11 apple cultivars before and after bruising were studied in relation to their susceptibility to browning. The degree of browning has been determined by the simultaneous measurements of soluble (absorbance at 400nm) and insoluble (lightness) brown pigments. The sum of these two expressing the extent of browning, closely correlated with the amount of phenolics (hydroxycinnamic derivatives and flavan-3-ols) degraded. Maturity did not appear to greatly influence the development of browning.     

Composition and Radical Scavenging Capacity of Phenolic Compounds in Wheat-Chickpea Dough

The content, composition, and radical scavenging capacity of phenolic compounds in wheat-chickpea (60:40, w/w) flour and dough were studied in this research. The content of phenolic compounds in wheat-chickpea dough was almost twice as high as in the flour from which the dough was made. The addition of chickpea flour to wheat flour contributed to the improved scavenging capacity of dough. The wheat-chickpea dough had a lower maximal achieved scavenging capacity than wheat-chickpea flour, but higher than that of the wheat dough. The quercetin, genkwanin, and apigenin glucosides could be considered as stable components during the mixing of the wheat-chickpea dough. The wheat-chickpea bread retained the radical scavenging capacity which the dough had.     

气相色谱-质谱联用结合偏最小二乘法在生鲜牛、鸭混合肉含量判别分析中的应用

采用顶空固相微萃取（headspace solid-phase micro extraction,HS-SPME）和气相色谱-质谱联用（gas chromatography-mass spectrometry,GC-MS）技术提取和分析生鲜牛、鸭混合肉中的挥发性化合物,利用偏最小二乘（partial least squares,PLS）法对GC-MS数据进行建模,对不同比例生鲜牛、鸭混合肉进行判别分析。结果表明：生鲜牛、鸭混合肉中共鉴定出39 种挥发性化合物;PLS模型可以有效区分不同比例生鲜牛、鸭混合肉,利用训练集和验证集数据验证模型,评估均方差为3.455 9,预测均方差为4.068 9,PLS模型对不同比例生鲜牛、鸭混合肉的预测准确率较高。本方法在判别不同比例生鲜牛、鸭混合肉方面准确性较高。     

不同品种蓝莓品质特性及聚类分析

通过对山东省14 个主栽蓝莓品种的感官品质、营养品质、加工品质等指标进行测定,并采用聚类分析法评价蓝莓品种的综合品质,从而筛选出品质较佳的蓝莓品种。结果表明：不同品种蓝莓品质存在差异,以抗氧化物质含量、出汁率、固酸比差异较大。品种‘L5’花色苷含量最高（617.46 mg/100 g）且固酸比最大（47.78%）;‘蓝塔1’出汁率最高（78.43%）;‘蓝塔2’总糖含量最高（10.75%）。14 个品种可聚为5 类,第1类为‘37-1’、‘奥尼尔’、‘北陆’和‘B’;第2类为‘埃利奥特1’、‘布尔吉塔’、‘蓝丰’及‘蓝塔1’;第3类包括‘埃利奥特2’、‘杜克’和‘Z’;‘H34’和‘蓝塔2’聚为第4类;‘L5’为第5类。经分析初步评价,第2类为适宜加工果汁果酒的优良品种;第3类为适宜贮藏的蓝莓品种;第4类为适宜鲜食的优良品种;第5类为加工果酱、果脯的优良品种。     

偏最小二乘回归法分析藏鸡胸肉质地特性

为揭示藏鸡肉独特的质地特性,探寻鸡胸肉质地特性与其化学成分和微观结构的关联性,本研究对5 种不同的鸡肉原料（藏鸡、与藏鸡同日龄或体质量接近的雪山草鸡、淘汰蛋鸡（对照）和白羽肉鸡（对照））进行剪切力、质地剖面分析（texture profile analysis,TPA）和应力松弛特性测定,并将上述质地特性分析结果和鸡肉的基本化学指标（水分质量分数、粗脂肪质量分数、粗蛋白质量分数、胶原蛋白质量分数、pH值）、组织学特征（肌纤维直径和密度）进行关联性分析,利用偏最小二乘回归（partial least squares regression,PLSR）法揭示影响鸡肉质地特征的显著因素。结果发现,利用PLSR能够将多个与肌肉质地特性相关的化学指标量化为鸡肉品质综合评价指标,其中剪切力的预测模型更适合预测鸡肉的质地特性。该模型的R2X为0.621,R2Y为0.739,模型拟合效果较好。Q2cum在0.6以上,说明该模型的可预测性能够被接受。载荷图显示剪切力与pH值、总胶原蛋白质量分数和肌纤维直径呈显著正相关（P＜0.05）,而与粗脂肪质量分数、可溶性胶原蛋白质量分数、胶原蛋白溶解性和肌纤维密度呈显著负相关（P＜0.05）。贡献度评价结果显示,胶原蛋白溶解性、肌纤维密度、可溶性胶原蛋白质量分数和肌纤维直径4 个指标均在模型中贡献显著。本研究可为从质地特性角度揭示藏鸡胸肉特有“咀嚼感”提供数据支持,并为丰富肉的力学特性研究提供一定的理论参考。     

Characterization of Bioactive Compounds from Monovarietal Virgin Olive Oils: Relationship Between Phenolic Compounds-Antioxidant Capacities

The characterization of bioactive components of virgin olive oil from nine varieties (Cuquillo, Empeltre, Manzanilla, Cornicabra, Picual, Arbequina, Lechin, Picudo, and Hojiblanca) has been carried out. Carotenoids, chlorophylls, α-tocopherol, fatty acids, total phenols, and individual phenols were determined. The antioxidant capacity was evaluated by 2,2′-diphenyl-1-picrylhydrazyl and 2,2′-azinobis (3-ethylbenzothiaziline-6-sulfonate) radical scavenging capacity assay, ferric reducing antioxidant potential assay, and oxygen radical absorbance capacity assay. Twelve phenolic compounds were detected and quantified by high-performance liquid chromatography with diode-array detection. Dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol, oleuropein, and ligstroside aglycones were the major components in all the samples. Principal component analysis confirmed that Manzanilla, Lechin, Cuquillo, and Hojiblanca var. were the most similar. Furthermore, these results showed that the antioxidant capacity measured by different assays was highly influenced by the phenolic content, especially the dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol.     

洛阳烤烟风格彰显度与常规化学成分的关系

通过对浓香型产区洛阳中部烟叶的120份烟叶样品进行检测分析,研究了常规化学指标与浓香型彰显度的关系。运用回归分析和描述性统计分析对数据进行处理,结果表明,当总植物碱的含量在2.0%~2.5%、钾含量在1.6%以上、糖碱比在10左右、钾氯比在5~7、氮碱比在0.7左右时浓香型风格彰显度较高。经过逐步回归分析,建立了风格彰显度与常规化学成分的回归模型,分析了风格指标和化学成分指标的相关关系,得出浓香型彰显度与总植物碱和糖碱比呈正相关,与氯、钾氯比、氮碱比呈负相关关系。     

3 种梨果实发育过程中酚类物质及其抗氧化能力分析

为进一步了解新疆主要栽培品种梨生长发育期果实酚类物质和抗氧化能力的变化规律,选取‘库尔勒香梨’‘早酥梨’及其杂交后代‘新梨7号’果实为试材,对其总酚、总黄酮、酚类物质含量以及1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力和2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）阳离子自由基清除能力进行分析。结果表明：3 种梨果实总酚含量、总黄酮含量、DPPH自由基清除能力在整个生长发育过程中总体呈逐渐降低的变化趋势,ABTS阳离子自由基清除能力呈先降低后升高再降低的变化趋势,花后50 d‘早酥梨’果实中总酚和总黄酮含量、DPPH自由基清除能力最高,分别达23.10、32.25 mg/g和29.12 μmol/g;花后80 d,‘早酥梨’果实ABTS阳离子自由基清除能力最高,达80.74 μmol/g。不同生长发育期同品种梨果实的酚类物质含量均存在明显差异,果实中的熊果苷、儿茶素、绿原酸、表儿茶素、槲皮葡萄糖苷、山柰酚-3-O-葡萄糖苷含量总体逐渐降低,其中熊果苷含量最高,平均值为5 797.82 μg/g,其次是绿原酸含量,平均值为1 781.02 μg/g。梨果实中总黄酮、总酚、熊果苷、儿茶素、绿原酸、表儿茶素含量与DPPH自由基清除能力呈极显著正相关（P＜0.01）。3 种梨幼果期（花后50 d）酚类物质及抗氧化能力较高,‘早酥梨’总酚含量、总黄酮含量、DPPH自由基清除能力和ABTS阳离子自由基清除能力均比‘库尔勒香梨’和‘新梨7号’高。     

7种芸豆中酚类化合物组成及其抗氧化活性

摘 要 对7种不同颜色芸豆的酚类化合物组成和抗氧化活性进行研究。结果表明：7种芸豆的总酚含量范围为0.91~4.96 mg GAE/g DW,黄酮的含量范围为3.29~12.87 mg RE/gDW,其中黑色芸豆的总酚含量最高;绿原酸、3,4,二羟基苯甲酸、对羟基苯甲酸是芸豆中的主要酚类物质,黑芸豆中3,4,二羟基苯甲酸的含量最高（28.91 ug/g DW）;红花色芸豆的DPPH自由基清除能力（7.38 mg TE/g DW）、ABTS+自由基清除能力（16.44 μmol TE/g DW）和铁离子还原抗氧化能力（9.26 μmol TE/g DW）相对较高;总酚的含量与三个抗氧化值极显著相关（p<0.01）。芸豆含有丰富的酚类化合物,并且表现出一定的抗氧化活性,可以作为优良的功能食品原料。