茶叶中粗纤维的测定检测方案(纤维测定仪)

智能文字提取功能测试中

F&F-F-001-2014/A1 VELPSCIENTIFICACRUDE FIBER DETERMINATION IN TEA APPLICATION NOTE Crude Fiber Determination in Teaaccording to ISO 15598：1999 Reference：ISO 15598：1999 Tea -Determination of crude fibre content Tested with VELP Scientifica FIWE 3 Fiber Analyzer (Code F30520201). 名称：北京盈盛恒泰科技有限责任公司 网址：www.ensoultech.com E-mail： sales@ensoultech.com Introduction Fiber is the part of fruits and vegetables (lignin， cellulose， hemicellulose， pectin) that cannot be digested and assimilatedby the human gastrointestinal tract. However， fiber analysis is important for： ●Nutritional reason： the quantity of fiber is important to keep the digestive system healthy and functional.Too much fiber can cause digestive problems； a low fiber intake irregularities in the functioning of the digestive tract. LLegal reason： authorities of almost all countries require manufacturers of food & feed products to declare the fibercontent as part of the nutritional table. Chemically， fiber is defined as indigestible residue， after boiling with diluted solutions of strong mineral alkalies andacids. Fiber Determination in Tea according to the ISO 15598：1999 The suitably grinded sample is treated with boiling sulfuric acid solution and sodium hydroxide solution. The residue isseparated by filtration， washed， dried， weighed and then ashed. The loss in mass resulting from ashing is the crude fibercontent. Reagents -Celite 545 -HCI1% -H2SO4 0.255 M： 125ml H2SO4 20 % in 2 L -Ethanol>95% - NaOH 0.313 M： 1.5 g NaOH in pellets dissolved in 1 L-Octanol - Acetone Analysis Procedure The diagram below shows the steps involved in the procedure： Grind the sample using a mill (particle size 1mm). Weigh into the crucible 1 g of celite and 1 g of homogeneus grinded sample (W1) with an accuracy of ±1 mg andposition the crucible (P1 type -Code A0000139) into the FIWE unit. The sample must to be homogeneous. Add 150 ml of pre-heated reagent H2SO4 0.255 M and 3-4 drops of octanol： boil 30 minutes exactly from the beginningof the boiling. At the end， connect to vacuum for acid draining. Use the water spray device (A00001135) in order to remove the residues of sample that could have been remained onthe glass columns. Repeat the same operations for the first reagent， using as second reagent NaOH 0.313 M. Wash the residues using hydrochloric acid solution and boiling water again. Then twice with ethanol >95% and three times with acetone. After draining， remove the crucibles and determine the dry weight after drying into an oven at 103 °C for two hours. Let cool the crucibles in a desiccator up to constant weight. This weight represents the crucible containing crude fiber and ashes (W2). Place the crucibles in a muffle at 550°C， starting from room temperature， for three hours and weigh again after coolingin a desiccator. This weight represents the crucible containing ashes (W3). 名称：北京盈盛恒泰科技有限责任公司 地址：北京市西城区广安门外大街168号朗琴国际大厦B座603室 电话：010-83993592 网址：www.ensoultech.com E-mail： sales@ensoultech.com Calculation W1= sample weight (1g) W2= crucible weight with fiber and ashes， after drying in an oven at 103 °C for 2 h W3= crucible weight with ashes， after muffle at 550 °C for three hours Typical Results on Classic Tea (repeated twice) W1 (g) W2 (g) W3 (g) Fiber %(m/m) 1.000 31.470 31.337 14.013 0.996 31.372 31.241 13.886 1.009 31.399 31.267 13.827 0.992 31.546 31.417 13.731 1.006 31.437 31.302 14.149 1.001 31.590 31.459 13.835 Average±SD% 13.907±0.137 RSD%* 0.985 * RSD%=(Standard Deviation * 100)/ Average The crude fibre content is expressed as a mass fraction， in percent， of the product on a dry basis. Conclusion The use of an extraction apparatus purposely devised for this method as FIWE unit makes very easy the standardizationof analytical conditions. The FIWE Series is suitable for fiber determination in tea. Benefits of FIWE are： 3 or 6 positions simultaneously： FIWE units can support up to 3 (FIWE 3) or 6 (FIWE 6) crucibles.Samples can also be processed individually Time saving： fast analysis (2 hours with FIWE vs. 6 hours manually) ● Easy to use： convenient filtration， with pump and air pressure Precision： high reproducibility of the results： ±1% relative or better In order to avoid losses of fiber， it’s important to remember that crucibles life is around 20-30 analyses， because thefritted filter could be damaged from basic and acid solutions. Hence it's suggested to change them after 20-30 analyses. E-mail： sales@ensoultech.com 地址：北京市西城区广安门门大街朗琴国际大厦B座电话：       纤维是水果和蔬菜(木质素、纤维素、半纤维素、果胶)中不能被人体胃肠道消化吸收的部分。然而，纤维分析是重要的：      营养原因：纤维的数量对保持消化系统的健康和功能很重要，过多的纤维会导致消化问题，低纤维摄入量消化道功能紊乱。      法律原因：几乎所有国家的当局都要求食品和饮料制造商，饲料产品应将纤维含量列为营养表的一部分。从化学上讲，纤维被定义为不可消化的残留物，用强矿物碱和酸的稀释溶液煮沸后。检测样品：茶叶检测仪器：纤维素测定仪FIWE3,意大利VELP检测结果：结论：使用专门为这种方法设计的萃取装置作为FIWE单元，使分析条件的标准化非常容易。FIWE系列产品适用于茶叶中纤维含量的测定。FIWE的好处是:3或6个位置同时：FIWE单位可以支持多达3 (FIWE 3)或6 (FIWE 6)坩锅样品也可以单独操作节约时间：快速分析(FIWE 2小时和手动6小时)精度：高重现性的结果:±1%或更好