过氧化值的碘化钾——硅胶试剂比色测定

本文提出了过氧化值的微量测定法。碘化钾——硅胶试剂同油脂中过氧化物反应所放出的碘在0.01N盐酸溶液中和淀粉生成兰色络合物。然后,在560毫微米波长进行比色测定。     

硬脂酰乳酸钠对铜皂络合比色法测定酸价干扰的固相萃取清除工艺

为清除合成乳化剂硬脂酰乳酸钠(SSL)对铜皂络合比色技术测定油脂酸价过程的正向干扰,开发了一种固相萃取(SPE)清除SSL的技术。用含2%异丙醇的环己烷为固相萃取流动相和油脂样品溶解液,通过离子排斥色谱检测油脂皂化水解后释放的游离乳酸的含量,间接评估SPE净化处理前后油脂中的SSL含量,并结合铜皂络合比色技术测定的酸价变化,评价所建立的SPE技术对去除油脂中SSL的效果。结果表明：SPE技术可有效去除油脂中的SSL,明显消除油脂中SSL对铜皂络合比色法测定酸价的干扰,不会导致油脂样品脂肪酸含量损失。对于含SSL的食用油脂试样,经SPE技术净化处理后,铜皂络合比色法测定酸价过程的干扰明显降低。     

三种方法测定水产品中亚硫酸盐残留量比较分析

通过3种方法对水产品中亚硫酸盐残留量(以二氧化硫计)进行测定,比较测定方法的有效性与差异。采用比色法(盐酸副玫瑰苯胺法)、蒸馏-碘滴定法、离子色谱法对水产品中的亚硫酸盐进行测定,运用统计学手段对结果进行分析。结果表明,3种方法的最低定量限、重复性试验结果均满足要求,蒸馏-碘滴定法回收率结果较低。配对t检验发现3种方法测定的亚硫酸盐残留量相关性显著,离子色谱法与比色法的测定样品结果无明显差异(P0.05),具有较好一致性,可作为一种替代的检测方法,用于水产品中亚硫酸盐残留量的控制。     

两种方法测定板栗直链淀粉含量的比较

比较碘比色法和碘电位滴定方法测定安徽大红袍和蜜蜂球两种板栗直链淀粉的含量,结果表明:两种方法测得的大红袍板栗直链淀粉含量均高于蜜蜂球板栗,碘比色法测得两种板栗直链淀粉的含量均高于碘电位滴定法.两种测定方法操作均快速简便,但与传统碘比色法相比,碘电位滴定法标准工作曲线采用多个函数拟合的方法绘制而成,直线回归方程相关系数更趋近于1,测得结果的稳定性、重复性较好.是测定板栗直链淀粉含量的一种科学合理有效的新方法.     

食品中碘测定的条件试验

食品中碘的测定常采用溴氧化,生成碘酸盐,遇碘离子析出碘,经淀粉显色,以比色法测定。本文对测定的各条件进行了详细试验,并进行了回收试验。 食品;;碘;;比色分析     

食品中亚硝酸盐含量测定的研究

亚硝酸盐含量的测定是食品检测中重要的检测指标之一,现行的检测方法很多。文中采用了新的检测方法,利用亚硝酸根在酸性条件下跟碘离子反应,生成碘单质,再用硫代硫酸钠滴定法碘单质,间接测定食品中亚硝酸盐的含量。实验中还研究了淀粉用量、不同酸性物质和不同pH等反应条件对回收率的影响。     

黄酒和米酒中氨基酸态氮测定方法的比较

为了探究茚三酮比色法在黄酒和米酒氨基酸态氮测定中的适用性,首先对可能影响茚三酮比色法测定结果的黄酒和米酒特性因素进行了考察分析,然后与甲醛滴定法及氨基酸分析仪进行比较,对17个黄酒和米酒样品进行了测定分析。结果表明,黄酒和米酒的色泽、总酸和酒精度等特性,对茚三酮比色法的测定结果无显著影响。茚三酮比色法与甲醛滴定法测定结果之间具有较好的线性关系,但对于米酒等氨基酸态氮含量较低的样品,茚三酮比色法具有更高的精密度和准确性。对照氨基酸分析仪分析结果,甲醛滴定法更适于表征产品的总体氨基酸含量,而茚三酮比色法则能更准确反映发酵过程中的α-氨基酸含量,且对于氨基酸态氮含量较低的米酒产品测定结果相对更为准确。     

储存期间鱼粉中脂质的劣变规律

鱼粉在储存过程中油脂易受外界环境的影响发生氧化劣变,导致鱼粉的品质下降。通过检测油脂的过氧化值(POV)、酸价(AV)、硫代巴比妥酸值(TBA),获得3种不同产地鱼粉在自然储存条件下油脂品质的变化规律。以期得到有价值的数据,服务于鱼粉的实际储存。研究结果表明:在自然条件下通风、避光储存15个月后,进口鱼粉(秘鲁)、国产鱼粉(玉环)、国产鱼粉(温岭)的AV分别由2.01、1.11、2.43 mg/g升至7.23、6.22、6.79 mg/g。TBA分别由15.5、8.96、7.30 mg/kg升至43.79、34.63、28.34 mg/kg。POV分别上升到16.97、24.64、16.62 mmol/kg后开始下降;研究还证明了脱脂显著降低了鱼粉AV、TBA、POV的含量及其在储存过程中的AV、TBA、POV的生成量,脱脂利于鱼粉的储存。     

三种藏药对食用油脂抗氧化性的初步研究

研究了唐古特雪莲、乳白香青、小米草乙醇提取物的抗氧化活性。采用烘箱高温诱导油脂发生过氧化反应,利用Na2S2O3-I2滴定法,测定不同时间油脂的POV作为评价抗氧化性能的依据,初步研究了3种藏药对常用食用油脂的抗氧化作用。结果表明,3种藏药乙醇提取物对所选的5种食用油脂均有一定的抗氧化效果。     

深色食用油脂中过氧化值的测定

目的 比较手动滴定法和电位滴定法对过氧化值的检测结果, 提高过氧化值测定的准确性, 探索测定深色油脂中过氧化值的适宜方法。方法 用手动滴定法和电位滴定法分别测定深色油脂和浅色油脂的过氧化值, 对检测结果进行对比, 选择最优的检测方法, 并进行方法学验证。结果 当样品为浅色样品时, 2种方法测定过氧化值的差异小, 但当样品为深色样品时, 只能用电位滴定的方法来测定, 手动滴定无法判断终点。电位滴定法加标回收实验的回收率为97.55%~104.84%, 相对标准偏差为0.9%~2.2%, 满足实验要求。结论 相比手动滴定法, 电位滴定方法更适用于食用油脂中过氧化值的测定。     

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.     

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     

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.     

National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan"

In Apri Commi major p Plan＂ （h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the ＂13th Five-Year ereafter referred to as ＂The Announcement＂）     

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 scientific     

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,     

Anti-mutagenic compounds from corn

In previous studies with aflatoxin-contaminated corn an uncharacteristic response for AFB₁ in the Salmonella/microsomal mutagenicity assay (Ames test) was observed and the presence of anti-aflatoxin factors in the corn was suggested. In the current study, corn was extracted and fractionated using thin layer chromatography (TLC) using different developing solvent systems and the Ames test was used to monitor for anti-mutagenic activity in the corn fractions. Both Salmonella tester strains TA98 and TA100 with metabolic activation (S9) were used. Several corn fractions, at different stages in the isolation and purification process, showed anti-mutagenic dose-responses when exposed to pure AFB₁. Corn extracts were non-toxic to the tester strains and TLC fractions that showed the best anti-mutagenic dose-responses were selected for further partial characterization analyses.