核桃种皮中多酚的测定及种皮对核桃贮藏品质的影响  

Determination of total polyphenol from walnut kernel pellicle and the effect of walnut kernel pellicle on walnut storage quality

作　　者：张天财[1] 陈朝银[1] 赵声兰[2] 张春梅[2] 武万兴[1] 

机构地区：[1]昆明理工大学,云南昆明650500 [2]云南中医学院,云南昆明650500

出　　处：《食品工业科技》2013年第20期65-69,74,共6页Science and Technology of Food Industry

基　　金：科技部科技支撑计划项目(2011BAD46B00);云南省科技计划项目(2009EB081;2011AB006)

摘　　要：以核桃种皮为原料，没食子酸为对照品，建立核桃种皮中总酚测定的Folin—Ciocalteu比色法，并考察了贮藏过程中核桃种皮多酚对核桃仁品质的影响。研究表明，Folin—CiocalteuI：E色法测定核桃多酚含量的适宜条件为，样品提取液1mL，Folin—Ciocalteu试剂1．5mL，20％碳酸钠溶液lmL、反应温度60℃、反应时间60min、测定波长765nm，样品提取溶剂为60％乙醇，平均回收率99．86％（RSD2．87％）。没食子酸对照品在4．4—30．8μg／mL范围内吸光度与其质量浓度呈良好的线性关系，R2=0．9994。该法操作简单、精密度高、稳定性好、回收率高，可用于测定核桃种皮中多酚含量。用该法测定核桃不同部位多酚分布为：核桃种皮（21．73％）〉核桃青果皮（6．37％）〉核桃壳（2．92％）〉核桃仁（0．77％）。核桃贮藏过程中。种皮中总酚含量先增加后趋于平稳，酸价和过氧化值是一直增加的．说明种皮对核桃品质变化影响较小。To establish an assay method, Folin-Ciocalteu colorimetric was used to determine the total polyphenol in walnut kernel pellicle（WKP） and study the influence of polyphenol on walnut kernel quality during the process of storage. WKP and gallic acid were used as raw material and standard,respectively. The results indicated that the optimum conditions for determining total polyphenol were as following：1.0mL of the WKP extract polyphenol, 1.5mL of Folin-Ciocalteu reagent dosage and 1.0mL of 20% sodium carbonate solution, treatment at 60℃ for 60min and 60% ethanol as extract solvent,the average spiked recovery was 99.86%,with a RSD of 2.87%. There was a good linearity between the absorbance and gallic acid concentration from 4.4 to 30.8ug/mL （FF=0.9994） in 765nm. This method was easy to operate, accurate, sensitive, stable and high recovery rate. It could be used as an appropriate method to measure the polyphenols in WKP. The distribution of polyphenol in walnut was WKP （21.73%） 〉walnut peel （6.37%） 〉walnut shell （2.92%） 〉walnut kernel （0.77%）. During the process of walnut storage,the polyphenol content of WKP increased quickly and then tended to be stable while the acid and peroxide value was increasing all the time. WKP had little effect on the quality of walnut.

关 键 词：核桃 多酚 Folin—Ciocalteu比色法 贮藏 过氧化值 酸值 

分 类 号：TS207.3[轻工技术与工程—食品科学]