DNS光度法测定风味鱿鱼中淀粉、还原糖和蔗糖的含量
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摘要
为测定风味鱿鱼中淀粉、还原糖和蔗糖的含量,取2份样品(每份3～5g),一份样品经水溶解及在盐酸溶液的水解作用下分成供测定原含还原糖和由蔗糖水解产生的还原糖在内的总还原糖测定的两部分试样溶液;另一份样品经乙醚萃取除去脂肪和用水溶解分离蔗糖后,将留下的不溶物通过在盐酸溶液中回流等操作将其中淀粉水解产生单糖,经过滤后取其滤液作为测定淀粉的试样溶液。从上述3份试样溶液中各分取2.0mL溶液,用DNS光度法测定其中还原糖的含量并换算成上述3组分的含量。用葡萄糖标准溶液制作工作曲线。在测定淀粉试液的制备中,对除去蔗糖的处理进行改进,在加水溶解的操作中增加了3～5次的重复操作,使样品的不溶解部分中残留的可溶性糖大大降低,例如未进行改进时测定得到的不溶物中糖含量分别为27.0,62.2mg·g-1的两份样品,对方法进行改进后,不溶物中糖含量依次降为0.32,0.63 mg·g-1,分别降低了98.8%,99.0%,保证了淀粉测定结果的准确性。
For determination of starch,reducing sugar and sucrose in flavoured squid,2 portions of sample(3-5 g each)were taken.In one portion of the sample,after dissolution with water and hydrolysis of hydrochloric acid solution,the sample solution was subdivided into 2 aliquots,one for determination of reducing sugar contained originally,and another for determination of total reducing sugar including those derived from sucrose by hydrolysis.For another portion of the sample,after removal of fat by extraction with ether and separation of sucrose by dissolution with water,the insoluble was refluxed in hydrochloric acid solution to have the starch hydrolyzed to give monosaccharide,and after filtration,the filtrate was used for determination of starch.Aliquots of 2.0 mL was taken separately from each of the 3 sample solutions described above and contents of reducing sugar(or mono saccharide)in these aliquots were determined by the DNS photometry by conversion calculation.Standard glucose solution was used to prepare calibration curve.An imporatant revision on the procedure of separation of sucrose in the preparation of sample solution for determination of starch was made by replicating the water-dissolution process by 3-5 times according to the sucrose content in the sample,thus leading to a great decrease of residual amount of soluble sucrose in the insoluble.For instance,in 2 samples of flavoured squid with low and high contents of sucrose,amounts of sucrose remained in the insoluble found by the orignal procedure were 27.0 mg·g-1 and 62.2 mg·g-1,while the amounts found by the revised procedure were decreased to 0.32 mg·g-1 and 0.63 mg·g-1,with rate of lowering of 98.8% and 99.0%.Hence,accuracy of analytical results of starch contents was ensured by the modified procedure.
For determination of starch,reducing sugar and sucrose in flavoured squid,2 portions of sample(3-5 g each)were taken.In one portion of the sample,after dissolution with water and hydrolysis of hydrochloric acid solution,the sample solution was subdivided into 2 aliquots,one for determination of reducing sugar contained originally,and another for determination of total reducing sugar including those derived from sucrose by hydrolysis.For another portion of the sample,after removal of fat by extraction with ether and separation of sucrose by dissolution with water,the insoluble was refluxed in hydrochloric acid solution to have the starch hydrolyzed to give monosaccharide,and after filtration,the filtrate was used for determination of starch.Aliquots of 2.0 mL was taken separately from each of the 3 sample solutions described above and contents of reducing sugar(or mono saccharide)in these aliquots were determined by the DNS photometry by conversion calculation.Standard glucose solution was used to prepare calibration curve.An imporatant revision on the procedure of separation of sucrose in the preparation of sample solution for determination of starch was made by replicating the water-dissolution process by 3-5 times according to the sucrose content in the sample,thus leading to a great decrease of residual amount of soluble sucrose in the insoluble.For instance,in 2 samples of flavoured squid with low and high contents of sucrose,amounts of sucrose remained in the insoluble found by the orignal procedure were 27.0 mg·g-1 and 62.2 mg·g-1,while the amounts found by the revised procedure were decreased to 0.32 mg·g-1 and 0.63 mg·g-1,with rate of lowering of 98.8% and 99.0%.Hence,accuracy of analytical results of starch contents was ensured by the modified procedure.
引文
[1]马晶晶,王际英,张得民,等.采用3,5-二硝基水杨酸比色法测定饲料总淀粉含量[J].中国饲料,2010(14):38-40.
[2] REN J,LI J F,ZHANG J,et al.A method for rapid determination of total sugar content based on 3,5-dinitrosalicylic acid colorimetry[J].Heilongjiang Science,2017,8(10):66-69.
[3]尹建雄,卢红,谢强,等.3,5-二硝基水杨酸比色法快速测定烟草水溶性总糖、还原糖及淀粉的探讨[J].云南农业大学学报,2007,22(6):829-832.
[4]李环,陆佳平,王登进.DNS法测定山楂片中还原糖含量的研究[J].食品工业科技,2013,34(18):75-77.
[5]杨宁,王伟明,姚琳,等.3,5-二硝基水杨酸法测定发酵型果露酒中总糖含量[J].中国酿造,2018,37(1):181-184.
[6] LINDSAY H.A colorimetric estimation of reducing sugars in potatoes with 3,5-dinitrosalicylic acid[J].Potato Research,1973,16(3):176-179.
[7]陈旭红.旋光法测定木薯粗淀粉的含量[J].食品工业科技,2000,21(2):64-65.
[8]王黎明.马铃薯中粗淀粉含量的测定方法———旋光法[J].宁夏农林科技,2010(6):51-51.
[9] GB 5009.9-2016食品安全国家标准食品中淀粉的测定[S].
[10] GB 5009.8-2016食品安全国家标准食品中果糖、葡萄糖、蔗糖、麦芽糖、乳糖的测定[S].
[11]吴东林.烤鱼片鱿鱼丝等产品中淀粉含量的测定[J].现代食品,2015(21):53-55.
[12] GB/T 27417-2017合格评定化学分析方法确认和验证指南[S].
[2] REN J,LI J F,ZHANG J,et al.A method for rapid determination of total sugar content based on 3,5-dinitrosalicylic acid colorimetry[J].Heilongjiang Science,2017,8(10):66-69.
[3]尹建雄,卢红,谢强,等.3,5-二硝基水杨酸比色法快速测定烟草水溶性总糖、还原糖及淀粉的探讨[J].云南农业大学学报,2007,22(6):829-832.
[4]李环,陆佳平,王登进.DNS法测定山楂片中还原糖含量的研究[J].食品工业科技,2013,34(18):75-77.
[5]杨宁,王伟明,姚琳,等.3,5-二硝基水杨酸法测定发酵型果露酒中总糖含量[J].中国酿造,2018,37(1):181-184.
[6] LINDSAY H.A colorimetric estimation of reducing sugars in potatoes with 3,5-dinitrosalicylic acid[J].Potato Research,1973,16(3):176-179.
[7]陈旭红.旋光法测定木薯粗淀粉的含量[J].食品工业科技,2000,21(2):64-65.
[8]王黎明.马铃薯中粗淀粉含量的测定方法———旋光法[J].宁夏农林科技,2010(6):51-51.
[9] GB 5009.9-2016食品安全国家标准食品中淀粉的测定[S].
[10] GB 5009.8-2016食品安全国家标准食品中果糖、葡萄糖、蔗糖、麦芽糖、乳糖的测定[S].
[11]吴东林.烤鱼片鱿鱼丝等产品中淀粉含量的测定[J].现代食品,2015(21):53-55.
[12] GB/T 27417-2017合格评定化学分析方法确认和验证指南[S].