响应面法优化超声辅助提取牡丹籽粕中多酚工艺

采用超声辅助提取牡丹籽粕中多酚,分别考察液料比、乙醇体积分数、超声时间、超声温度、超声功率对多酚提取量的影响,在单因素试验的基础上,通过响应面法优化提取工艺。结果表明,超声辅助提取牡丹籽粕中多酚的最佳工艺条件为:超声功率300 W,液料比20∶1,超声时间98 min,乙醇体积分数80%,超声温度50℃。在最佳工艺条件下,牡丹籽粕中多酚提取量为17.42 mg/g。     

超声辅助吐温80提取发芽小米GABA和多酚的工艺优化

采用超声辅助吐温80优化发芽小米γ-氨基丁酸（gamma-amino butyric acid,GABA）和多酚提取工艺。以GABA和多酚得率为考察指标,通过单因素试验探究吐温80质量分数、超声温度、超声时间、料液比、超声功率对GABA得率的影响,设计正交试验优化GABA提取工艺;通过单因素试验探究吐温80添加量、超声温度、超声时间、料液比4个因素对多酚得率的影响,以响应面试验设计优化多酚提取工艺。结果表明：超声辅助吐温80提取GABA的最佳工艺条件为吐温80质量分数6%、超声温度35℃、超声时间25 min、料液比1∶18（g/mL）、超声功率126 W,此条件下GABA得率为4.70 mg/g;提取多酚的最佳工艺条件为吐温80质量分数9%、超声温度42℃、超声时间19 min、料液比 1∶12.5（g/mL）,此条件下多酚得率为 1.99 mg/g。     

响应面优化核桃分心木多酚超声辅助提取工艺

以核桃分心木为原料,利用响应面法对提取核桃分心木中多酚的工艺条件进行优化。在单因素试验的基础上,选取料液比、乙醇体积分数、超声时间、超声温度为自变量,根据Box-Behnken中心组合设计原理,以多酚的提取率为响应值进行响应面分析。结果表明,核桃分心木多酚最佳提取工艺为：料液比1∶62（g/mL）,乙醇体积分数50%,超声时间50 min,超声温度71℃,多酚提取率为6.98%。     

响应面法优化超声波提取核桃青皮多酚的工艺研究

以核桃青皮为原料,利用响应面法优化超声波提取多酚的工艺条件。在单因素试验的基础上,选择对多酚得率影响较为显著的超声功率、超声温度、液料比3个因素为自变量,以多酚得率为响应值,进行Box-behnken试验和响应面分析,得出最佳工艺条件为:超声功率670W,超声温度57℃,液料比21:1(mL:g),超声时间5 s,超声间隙时间5 s,超声全程时间25 min,搅拌速度400 r/min。在此条件下,多酚得率可以高达55.473 mg/g。     

响应面法优化超声辅助提取花生红衣多酚工艺

以花生红衣为原料,采用超声波辅助提取其中的多酚类物质。通过单因素试验对超声时间、超声功率、料液比、乙醇体积分数等工艺参数进行研究,并用响应面法优化提取工艺,建立二次多项数学模型。结果表明,花生红衣多酚提取的最佳工艺参数为超声时间24.4min、超声功率408W、料液比1:29.6(g/mL)、乙醇体积分数51%。结合实际操作,响应面优化的最优工艺参数调整为超声时间24min、超声功率410W、料液比1:30(g/mL)、乙醇体积分数51%,此条件下花生红衣多酚得率为8.95%。     

超声波辅助双水相提取叶下珠酚类物质的研究

联合超声波和双水相技术,采用响应面法进行优化叶下珠酚类物质的提取工艺,建立了超声时间、料液比、硫酸铵浓度、乙醇浓度对叶下珠酚类物质提取的数学模型,优化最佳提取工艺。结果表明:超声时间、料液比、硫酸铵浓度、乙醇浓度对叶下珠酚类物质的提取影响显著,这些因素对提取率的影响顺序为乙醇浓度料液比超声时间硫酸铵浓度;超声时间和乙醇浓度、硫酸铵浓度和乙醇浓度的交互作用对叶下珠酚类物质的提取影响显著,而超声时间和料液比、超声时间和硫酸铵浓度、料液比和硫酸铵浓度、料液比和乙醇浓度的交互作用对叶下珠酚类物质的提取影响不显著;最佳提取参数为超声时间46min、料液比1∶46(g/m L)、硫酸铵浓度22%、乙醇浓度29%,在此条件下叶下珠酚类物质的提取率为7.85%(n=3),与预测值无显著性差异。     

超声辅助提取黄皮果核多酚工艺的研究

天然多酚物质具有各种生物活性而受到广泛关注,从食品加工副产物中回收多酚等活性物质是研究热点。为了从黄皮果核中回收多酚,以黄皮果核为原料,利用超声波技术辅助提取多酚,并采用响应面法优化提取工艺。以多酚提取率为响应值,首先通过单因素试验考察乙醇浓度、超声时间、料液比对提取率的影响,选择因素水平,再通过Box-Behnken试验设计和响应面法优化黄皮果核多酚最佳提取参数。结果表明:乙醇浓度和料液比对提取率的影响显著,超声时间对提取率的影响不显著,料液比的影响最大,而超声时间的影响最小;乙醇浓度与超声时间的交互作用对提取率的影响显著,而乙醇浓度与料液比、超声时间与料液比对的交互作用都对提取率的影响不显著;黄皮果核多酚最佳提取工艺为乙醇浓度52%、超声时间49min、料液比1∶33g/mL,此条件下提取率为7.16mg/g,与预测值偏差0.57%,说明该模型用于提取黄皮果核多酚是可靠的。     

荸荠皮酚类物质超声波辅助提取工艺优化

采用超声波辅助提取荸荠皮中的酚类物质,考察溶剂种类、料液比、提取温度、超声功率及超声时间对酚类物质提取率的影响。在单因素试验的基础上,确定最佳提取溶剂,并利用响应面法优化工艺条件。结果表明,荸荠皮总酚的最佳提取工艺条件为:甲醇提取,料液比1:15 (g/mL),提取温度55℃,超声功率270 W,超声时间55 min,该条件下总酚含量的最大响应值为4. 42 mg/g;荸荠皮总黄酮最佳提取工艺条件为:甲醇提取,料液比1:20 (g/mL),提取温度60℃,超声功率240 W,超声时间55 min,该条件下总黄酮含量的最大响应值为15. 20 mg/g。     

响应面法优化玉米苞叶多酚提取工艺

为了探究玉米苞叶多酚的提取方法,应用单因素和响应面法优化试验设计对超声提取玉米苞叶多酚的工艺条件进行优化研究。分别考察乙醇体积分数、料液比、超声功率、超声温度对玉米苞叶多酚提取率的影响,并通过4因素3水平响应面法进行工艺优化,获得了超声提取的最优化条件和相应的回归方程。结果表明,超声提取的最优化条件为:乙醇体积分数49%、料液比1:58(g/m L)、超声功率175 W、超声温度74℃。在此条件下,得到玉米苞叶多酚的提取率为4.278 mg/g,与理论预测值基本吻合,为玉米苞叶的开发利用提供理论依据。     

沙棘籽多酚超声耦合真空提取工艺的研究

以沙棘籽多酚得率为指标,通过超声波耦合真空提取法确定沙棘籽多酚的最佳提取工艺。采用单因素和响应面设计相结合的方法,以料液比、超声温度、功率、提取时间为考察因素,优化沙棘籽多酚提取工艺。结果表明,超声耦合真空法提取沙棘籽多酚的最佳工艺条件为：超声功率260 W,液固比 20∶1,超声时间30 min,超声温度52 ℃,在此条件下多酚得率为（11.394±0.083）%。经验证,与模型预测值（11.422%）相比较无显著差异（P>0.05）。提示,运用超声波耦合真空法提取沙棘籽多酚稳定可靠,节能省时,具有实用价值,可用于工业化大规模生产。     

Natural pigments: carotenoids, anthocyanins, and betalains--characteristics, biosynthesis, processing, and stability

Pigments are present in all living matter and provide attractive colors and play basic roles in the development of organisms. Human beings, like most animals, come in contact with their surroundings through color, and things can or cannot be acceptable based on their color characteristics. This review presents the basic information about pigments focusing attention on the natural ones; it emphasizes the principal plant pigments: carotenoids, anthocyanins, and betalains. Special considerations are given to their salient characteristics; to their biosynthesis, taking into account the biochemical and molecular biology information generated in their elucidation; and to the processing and stability properties of these compounds as food colorants.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Tyrosinase, Laccase, and Peroxidase in Mushrooms (Agaricus, Crimini, Oyster, and Shiitake)

Enzyme assays and electrophoresis were used to monitor the activity of tyrosinase, laccase, and peroxidase in Agaricus bisporus (common cultivated button mushrooms and Crimini mushrooms), Oyster, and Shiitake mushrooms. The three enzymes could be differentiated using specific substrates and inhibitors. Tyrosinase seemed to be the major phenol oxidase in the Agaricus strains, while Oyster and Shiitake mushrooms had much lower levels. Peroxidase activity was low or undetectable in all types examined. Control of enzymatic browning in different mushroom types may depend upon the distribution of different oxidases within any given type.     

Polyphenols, Anthocyanins, Ascorbic Acid, and Radical Scavenging Activity of Rubus, Ribes, and Aronia

ABSTRACT: Total polyphenols, total anthocyanins, and reduced ascorbic acid were evaluated in berries belonging to the genera Rubus, Ribes, and Aronia by means of spectrophotometric and high-performance liquid chromatography (HPLC) techniques. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruit extracts was tested. Total polyphenols ranged from 140.6 to 888.5 mg/100 g fresh weight (FW), total anthocyanins ranged from 22.0 to 460.5 mg/100 g FW, and reduced ascorbic acid ranged from 12.4 to 153.8 mg/ 100 g FW. The average EC50 values for Aronia melanocarpa, Ribes nigrum, Ribes rubrum, Rubus fruticosus, and Rubus idaeus were 1.8, 2.8, 5.3, 6.4, and 8.2 mg FW, respectively. The results indicate that the fruits tested are good sources of natural antioxidants.     

Hormones, metabolites, and reproduction in Holsteins, Jerseys, and their crosses

Holsteins (HH), Jerseys (JJ), and their crosses in first (n=157) and second (n=107) lactation were used to determine if reproduction, progesterone (P4), insulin-like growth factor 1 (IGF-1), insulin, nonesterified fatty acids (NEFA), and milk production differed between genetic groups. Thirty-four cows were Holstein-Jersey (HJ) crosses, 46 were Jersey-Holstein (JH) crosses, 48 were purebred Holsteins (HH), and 29 were purebred Jerseys (JJ) in first lactation, whereas the second-lactation animals included 23 HJ, 35 JH, 35 HH, and 14 JJ. Blood samples were collected weekly for the first 10 wk postpartum. Analyses were conducted using the MIXED, chi-square, and GLIMMIX procedures (SAS Institute Inc., Cary, NC). Seasons of calving were cold (November to May) and hot (June to October) and were combined with year to form 8 year-seasons. Days open and number of services were affected by genetic group. The HH were open 169±8 d, which was greater than HJ (143±9 d), JJ (132±10 d), and JH (127±8 d). The HH had 2.4±0.1 services per pregnancy, which was greater than JH (1.9±0.1), but not different from HJ (2.1±0.2) or JJ (2.1±0.2). Concentrations of NEFA were greater in lactation 2 (0.52±0.02 mEq/L) than in lactation 1 (0.45±0.02 mEq/L) and decreased over the 10-wk period. Concentrations of NEFA were greater in the cold season except in yr 3. Insulin in lactation 1 (0.81±0.03 ng/mL) was greater than in lactation 2 (0.72±0.03 ng/mL); insulin decreased to wk 2 then gradually increased. The HJ had the greatest insulin concentrations (0.87±0.04 ng/mL) and the JJ had the lowest (0.66±0.04 ng/mL), and IGF-1 gradually increased over the 10-wk period. Milk production (actual yield in the first 305 d, not adjusted for fat and protein) was affected by genetic group, lactation number, year-season, and wk 1 insulin. The HH produced 10,348±207 kg of milk, which was greater than the HJ (9,129±230 kg), the JH (9,384±190 kg), and the JJ (7,080±240 kg). Milk production in lactation 2 (9,676±163 kg) was greater than that in lactation 1 (8,294±160 kg). The JJ (10.3±4.7%) had the highest frequency of mastitis. The chance of getting mastitis for HH (1.1±0.9%) differed from that for HJ (9.4±4.1%), JH (8.1±3.4%), and JJ (10.3±4.7%). Genetic group affected hormones and metabolites, which may partially explain differences in reproductive measures and milk yield.     

Water-, oil-, and soil-repellent treatment of textiles,artificial leather,and leather

Several products are on the market to realize water-, oil-, and soil-repellent properties on textiles or textile-related materials. To make an adequate and fast rating of repellent properties of finished textiles, different drop tests according to AATCC and ISO standards are commonly used. For evaluation of the repellent properties of solid substrates against different liquids often contact angle measurements are performed. The aim of the work presented here is to determine and evaluate the repellent effects gained by the application of three different finishing agents on three different substrates, such as polyester fabric, artificial leather, and leather. The main questions are at that point: It is possible to gain similar repellent effects with the same finishing product applied on different substrates? Do the different testing methods lead to comparable results? Is there a relation to the repellency against everyday consumer products as red wine, ice tea, or coffee? This article should help the reader to evaluate different testing methods and the influence on common substrates.     

Capsicum--production, technology, chemistry, and quality. Part V. Impact on physiology, pharmacology, nutrition, and metabolism; structure, pungency, pain, and desensitization sequences

The spice Capsicum is the fruit of the cultivated species of the genus Capsicum (family, Solanaceae), C. annuum principally, and C. frutescens L. to a lesser extent. A third variety of C. annuum var. annuum fruits, the large-sized, fleshy bell capsicum is used as a fresh vegetable and valued for its aroma, color, and crisp texture, but with no pungency. This variety is not considered in this series of reviews covering primary processing, production, international trade, chemistry, and biochemistry of functional components--the red keto carotenoids, the aromatic volatiles and the pungent capsaicinoids in Parts I to III. The valid qualitative aspects correlating the specific components of capsicum and their sensory responses are critically covered in Part IV. In this the concluding part of the series of reviews, the significant preference of the spice for initially evoking an aversive response, its potent physiological and pharmacological effects, and the aspects of structure-activity relationships of the pungent stimuli of the capsaicinoids are reviewed. The beneficial effects particularly associated with long usage by some ethnic groups and its safe consumption levels, with a critical review of the studies on the gastrointestinal tract, the cardiovascular system, the sensory system, thermoregulation, nutritional impacts, and an overview of the five series is also detailed.     

Simultaneous and Direct Determination of As, Bi, Pb, Sb, and Se and Co, Cr, Cu, Fe, and Mn in Milk by Electrothermal Atomic Absorption Spectrometry

Tungsten permanent modifier with coinjection of Pd(NO₃)₂ and W–Ru permanent modifiers are proposed for the direct and simultaneous determination of As, Bi, Pb, Sb, and Se (group 1) and Co, Cr, Cu, Fe, and Mn (group 2), respectively, in milk by graphite furnace atomic absorption spectrometry. The performance of modifiers was evaluated by means of thermal behavior of analytes, sensitivity, atomic signal profile, repeatability, graphite tube lifetime, and background intensity. An air-assisted pyrolysis step was necessary to quantitative elimination of the organic matter. After methods optimization, 14 commercial milk samples were analyzed. The found concentrations of As, Bi, Pb, Sb, Se, Co, and Cr were lower than their limit of detection (2.13, 2.21, 1.49, 1.63, 2.05, 1.0, and 1.2 μg L⁻¹, respectively). Concentrations of Cu, Fe, and Mn were in the 1.58–5.74 μg L⁻¹, 9.79–49.3 μg L⁻¹, and 2.25–4.08 μg L⁻¹ intervals, respectively. The limits of detection for Cu, Fe, and Mn were 1.7, 5.3, and 2.0 μg L⁻¹, respectively. The accuracy of methods was checked after analysis of two milk standard materials. Results for Cr, Cu, Fe, Mn, Pb, and Mn were in agreement with certified values of SRMs at the 95% confidence level. Accuracy was also evaluated by addition–recovery tests and recoveries in the 86–127% range were obtained for all elements. The use of pretreat platform of graphite tubes with W or W–Ru allowed enlarging the lifetime of atomizer in 750 heating cycles.