A new solid phase extraction coupled with high performance liquid chromatography method for quantitatively analyzing two fatty acid tryptamides (FATs), behenic acid tryptamide and lignocerinic acid tryptamide, was established. The cocoa shell content in cocoa powder was calculated according to the differences in FATs contents in the powder and shell. The samples were extracted by trichloromethane with vortex and ultrasonic extraction. The Venusil C18 chromatographic column was used and eluted with acetonitrile/tetrahydrofuran/water,followed by using a fluorescence detector. The results showed that these two FATs showed good linear relationship (r>0.999 1) within their linear range(50-1 000 μg/L). The detection and quantification limits were 0.03 mg/kg and 0.1 mg/kg, respectively. The spike recovery rate was 92%-103% and the RSDs was 2.1%-6.2%. In addition, FATs levels and the cocoa shell contents in cocoa powder samples were processed to establish a simple analysis model. The prediction values had good corresponding relationship with true values. The results showed that cocoa powder adulterated with 5% or more (mass fraction) cocoa shell could be identified by this method.
ZHANG Jiukui
,
JIA Nan
,
KE Runhui
,
WANG Shuo
,
LI Xiaobin
,
YIN Jianjun
. Determination of cocoa shell content in cocoa powder by highperformance liquid chromatography[J]. Food and Fermentation Industries, 2019
, 45(3)
: 261
-265
.
DOI: 10.13995/j.cnki.11-1802/ts.015641
[1] WILSON T, TEMPLE N J. Beverages in Nutrition and Health [M]. Humana Press, 2004:1-9.
[2] 胡明华,王琴,戴军,等. 多糖组分色谱指纹图谱聚类分析可可粉的掺假鉴别[J]. 食品与发酵工业, 2012, 38(8): 173-177.
[3] EEC (1973) Directive 73/241/EEC by the European Parliamentand the European Council relating tococoa and chocolate products intended for human consumption [S]. Official Journal of the European Communities L 228 of 16/08/1973:23.
[4] GB/T 20706—2006, 可可粉[S]. 北京:中国标准出版社, 2007.
[5] 金永生,朱卫娟,廖祥儒. 可可粉中几种外源植物源性成分的PCR检测[J]. 生物技术通报, 2008(5): 118-121.
[6] MEYER H. Zum determination of cocoa shells in cocoa products-discussion [J]. Ssswaren, 1962, 11: 644-645.
[7] FINCKE A, SACHER H. Investigation to estimate the purity of cocoa butter and fats from chocolates [J]. Swaren, 1963, 9: 428-431.
[8] IOCCC. International office of cocoa, chocolate and sugar confectionary, method for determination of blue value [S]. IOCCC, 1988:108.
[9] MÜNCH M, SCHIEBERLE P. A sensitive and selective method for the quantitative determination of fatty acid tryptamides as shell indicators in cocoa products [J]. Z Lebensm Unters Forsch A, 1999, 208:39-46.