响应面法优化金蝉花多糖提取工艺及抗氧化活性分析

通过考察液料比、浸提时间及浸提温度对金蝉花多糖含量的影响,在单因素试验基础上进行响应面优化提取工艺条件,并通过测定金蝉花多糖总还原力、清除1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-trinitrophenylhydrazine,DPPH）自由基、羟自由基（·OH）和超氧阴离子自由基（O2－·）的能力研究其体外抗氧化活性。结果表明,金蝉花多糖适宜的提取工艺参数为浸提时间130min、浸提温度80℃、液料比50∶1（mL/g）,在此条件下金蝉花多糖含量实际值为26.14mg/g。金蝉花多糖具有较好的抗氧化能力,其清除DPPH自由基、·OH、O2－·的半抑制质量浓度（IC50）分别为28.99μg/mL、0.19mg/mL和0.30mg/mL。     

蒲公英叶多糖超声波细胞粉碎辅助提取工艺优化及体外抗氧化活性

利用超声波细胞粉碎技术辅助提取蒲公英叶多糖，并采用响应面法对其提取工艺进行优化。研究超声功率、料液比、提取时间、温度对蒲公英叶多糖提取率的影响，在单因素试验的基础上进行响应面试验并对蒲公英叶多糖的抗氧化能力进行测定。结果表明，蒲公英叶多糖的最佳提取工艺为超声功率197 W、料液比1∶15（g/mL）、提取时间25 min，此工艺下多糖提取率为5.346%。蒲公英叶多糖具有一定的抗氧化活性，其对DPPH 自由基、羟自由基、超氧阴离子自由基的IC50 值分别为34.62、12.16、0.98 mg/mL。     

皂荚多糖超声波提取工艺优化及体外抗氧化活性研究

以皂荚多糖为研究对象,在单因素实验的基础上,采用响应面法对皂荚多糖的超声波提取工艺进行优化,并对多糖进行体外抗氧化活性的研究。结果表明:最佳提取工艺条件为:提取温度50 ℃,液料比35:1 (mL/g),提取时间30 min,超声功率285 W,提取3次,多糖得率为30.65%±0.25%。抗氧化实验表明,皂荚多糖具有一定的抗氧化能力,其对超氧阴离子自由基、DPPH自由基、羟自由基清除作用的IC₅₀分别为:10.3、6.9、1.5 mg/mL。     

响应面法优化松茸多糖酶法提取工艺及其体外抗氧化性分析

为确定复合酶（纤维素酶、果胶酶、中性蛋白酶）提取松茸多糖的最佳工艺,并对其体外抗氧化活性进行初步研究,在单因素试验的基础上,以料液比、pH值、酶解时间和酶解温度为影响因素,利用Box-Behnken方法进行四因素三水平试验设计,以多糖提取率为响应值,进行响应面分析;分别用邻苯三酚自氧化法和对DPPH自由基的清除作用测定松茸多糖的体外抗氧化性。结果表明：多糖提取的最佳工艺为料液比1∶40（g/mL）、pH 5、酶解温度35 ℃、酶解时间71 min,松茸多糖的提取率预测值为7.06%,验证值为6.95%,与预测值相对误差为1.56%;松茸多糖对超氧阴离子自由基和DPPH自由基具有较强的清除作用,其IC50值分别为0.565 mg/mL和0.454 mg/mL。因此,复合酶法提取松茸多糖高效、简单,可用作松茸多糖的提取工艺;松茸多糖具有明显的体外抗氧化活性。     

牛肝菌多糖的提取及抗氧化性研究

该试验以云南牛肝菌烘干粉末为原料,多糖得率为评价指标,从料液比、超声时间和超声温度等因素,对牛肝菌粉末粗多糖的提取工艺进行优化;同时对牛肝菌多糖清除1,1-二苯基苦基苯肼自由基（DPPH·）和羟基自由基（·OH）的能力进行研究。结果表明,牛肝菌粗多糖得率受各因素的影响程度依次为料液比＞超声时间＞超声温度。当料液比为1∶15（g∶mL）,超声时间为2 h,超声温度为60 ℃时,牛肝菌粗多糖得率可达41.76%。牛肝菌粗多糖对DPPH·和·OH的半抑制浓度（IC50）值分别为0.75 mg/mL和5.12 mg/mL,当多糖质量浓度为1 mg/mL、10 mg/mL时,多糖对DPPH·和·OH的清除率可达71.19%、80.69%。     

花椒水溶性多糖的提取及其体外抗氧化活性研究

通过正交实验,对水提法提取花椒多糖工艺进行了优化。实验结果表明,在选定的工艺条件下,各因素对花椒多糖提取率的影响顺序为提取时间〉提取温度〉料液比,最佳提取条件为料液比1：20、提取温度95℃、提取时间4h,在最佳工艺条件下测得花椒粗多糖提取率为3.49%。体外抗氧化活性实验表明,花椒多糖能有效地清除体外Fenton反应产生的·OH,当花椒多糖浓度在2.0mg/mL以上时,对羟自由基的清除率在50%以上。     

响应面优化紫果西番莲多糖提取工艺及抗氧化活性研究

以紫果西番莲为研究对象,采用单因素试验和响应面分析法优化紫果西番莲果肉多糖的提取工艺,考察液料比、超声时间、超声功率和超声温度对其多糖提取量的影响;以清除DPPH自由基和·OH能力评价紫果西番莲果肉多糖的抗氧化活性。结果表明:紫果西番莲果肉多糖最佳提取工艺为:液料比5 mL/g、超声时间20 min、超声功率330 W和超声温度70℃,测得紫果西番莲多糖的提取量为98.82 mg/g;紫果西番莲果肉多糖有一定的DPPH自由基和·OH的清除能力,其清除DPPH自由基、·OH的半抑制浓度(IC50)分别为66.97μg/mL和0.23 mg/mL。     

贵长猕猴桃多糖提取工艺及体外抗氧化功能

研究贵长猕猴桃果肉多糖、果皮多糖的提取工艺及体外抗氧化能力。采用正交试验优化贵长猕猴桃果肉、果皮多糖提取工艺参数,蒽酮-硫酸法测定多糖含量;用邻苯三酚自氧化及Fenton反应法测定贵长猕猴桃多糖抗氧化活性。结果表明：果肉多糖最优提取工艺参数为提取温度80 ℃、提取时间2 h、料液比1∶35（g/mL）,重复提取3 次,多糖提取率可达1.74%;果皮多糖最优提取工艺参数为提取温度70 ℃、提取时间2 h、料液比1∶25（g/mL）,重复提取3 次,多糖提取率可达1.16%。贵长猕猴桃果肉粗多糖、果皮粗多糖对O2 － •和•OH均具有很好的清除作用,果肉多糖清除O2 － •和•OH的IC50分别是12.4、41.3 μg/mL,果皮多糖清除2 种自由基的IC50分别是84.1、50.8 μg/mL。     

超声波提取雪莲薯多糖工艺优化及其对羟自由基的清除

以雪莲薯为原料,通过单因素和正交试验研究超声波提取多糖的工艺条件。结果表明,最佳提取工艺条件为提取时间15min、提取温度50℃、超声波功率80W、料液比1:30(g/mL),雪莲薯多糖得率为53.3%。提取效果影响大小的先后顺序为提取时间＞提取温度＞提取功率＞料液比。未脱蛋白多糖对羟自由基有较强的清除作用,IC50 为1.82mg/mL。脱蛋白后多糖对羟自由基清除作用得到显著的提高,IC50 为0.085mg/mL,比未脱蛋白多糖的清除作用提高了20 余倍。     

药桑叶多糖提取工艺优化及其降血糖活性研究

采用Box-Behnken试验设计对药桑叶多糖提取条件（液料比、提取温度、提取时间）进行优化,并用对硝基苯-α-D-吡喃葡萄糖苷（p-NPG）法对药桑叶多糖进行α-葡萄糖苷酶抑制活性测定。结果显示,药桑叶粗多糖提取最佳工艺为：在液料比25∶1（mL∶g）,提取温度90 ℃、提取时间3 h条件下,药桑叶粗多糖提取率最高为（13.39±0.53）%。降血糖初步研究结果为：药桑叶粗多糖对α-葡萄糖苷酶有较好的抑制活性,其半抑制浓度（IC50）为0.96 mg/mL。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.