4-Dimethylaminocinnamaldehyde (DMAC) Method for Determination of Total Proanthocyanidin Content in Grain Legumes

Abstract

A method based on the 4-dimethylaminocinnamaldehyde (DMAC) method was optimized for determination of total proanthocyanidin content in grain legumes using 96-well microplates. The recovery determined for a milled soybean material spiked with black soybean seed coat extract equivalent to 1.0, 2.0 and 4.2 mg/g of proanthocyanidin ranged from 96. 1 to 97. 9 %. Duplicate determinations of total proanthocyanidin content in eight different grain legumes were performed on three different days. Statistical treatment revealed that the relative standard deviation of the repeatability (RSD r) and the relative standard deviation of the intermediate reproducibility (RSD int) for determination of total proanthocyanidin content was 0.5 to 4.1 % and 0.9 to 4.7 %, respectively. The HorRat values (RSD int /predicted RSD R) ranged from 0.17 to 0.87. This demonstrates that the proposed method for determining total proanthocyanidin content in grain legumes had good intralaboratory reproducibility. The contents of proanthocyanidin, ranging from 0.33 to 2.97 mg/g, in 59 samples of black soybean determined by the DMAC method were strongly correlated to those determined by the vanillin-sulfuric acid method (r=0.980). However, the contents in black soybeans determined by the vanillin-sulfuric acid method were higher when compared with the DMAC method in almost all samples, when the content obtained by the DMAC method was directly compared to that obtained by the vanillin-sulfuric acid method.

Proanthocyanidins and Where to Find Them: A Meta-Analytic Approach to Investigate Their Chemistry, Biosynthesis, Distribution, and Effect on Human Health

“… Cluster distribution of proanthocyanidins based on the total proanthocyanidin content within plant families and according to previously published data [ 96 , 97 , 99 , 100 , 101 , 102 , 104 , 105 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 , 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 ]. Euclidean distances were calculated with the average linkage method.…”

Prediction of the Adult T-Cell Leukemia Inhibitory Activity of Blueberry Leaves/Stems Using Direct-Injection Electron Ionization-Mass Spectrometry Metabolomics

“…The PAC content was determined according to the DMAC protocol using a modification of the method of Oki et al [ 28 ]. Two different assay solvents were prepared.…”

Changes in Proanthocyanidin Content during the Processing of Umeshu, a Spirit-Based Liqueur of Japanese Apricot (Prunus mume Sieb. et Zucc.) Fruit

“…20 The results were expressed in terms of (+)-catechin equivalents. The total content of PA was determined following the DMAC method, 21 and the results were expressed in terms of (+)-catechin equivalents. An alternative method to determine the total PA concentrations involves the evaporation of the sample extract to dryness in a test tube.…”