Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, 145 FScN Building, St. Paul, USA.
Food Chem. 2013 Nov 15;141(2):1345-53. doi: 10.1016/j.foodchem.2013.03.021. Epub 2013 Mar 13.
Bitterness in whole wheat bread can negatively influence product acceptability and consumption. The overall goal of this project was to identify the main bitter compounds in a commercial whole wheat bread product. Sensory-guided fractionation of the crust (most bitter portion of the bread sample) utilising liquid-liquid extraction, solid-phase extraction, ultra-filtration and 2-D offline RPLC revealed multiple bitter compounds existed. The compounds with the highest bitterness intensities were selected and structurally elucidated based on accurate mass-TOF, MS/MS, 1D and 2D NMR spectroscopy. Eight bitter compounds were identified: Acortatarins A, Acortatarins C, 5-(hydroxymethyl)furfural(HMF), 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP), N-(1-deoxy-d-fructos-1-yl)-l-tryptophan (ARP), Tryptophol (TRO), 2-(2-formyl-5-(hydroxymethyl-1H-pyrrole-1-yl)butanoic acid (PBA) and Tryptophan (TRP). Based on the structures of these compounds, two main mechanisms of bitterness generation in wheat bread were supported, fermentation and Maillard pathways.
全麦面包的苦味会对产品的可接受性和消费产生负面影响。本项目的总体目标是鉴定商业全麦面包产品中的主要苦味化合物。利用液-液萃取、固相萃取、超滤和二维离线反相高效液相色谱法对面包皮（面包样品中最苦的部分）进行感官引导分级，发现存在多种苦味化合物。根据精确质量-TOF、MS/MS、1D 和 2D NMR 光谱，选择具有最高苦味强度的化合物，并对其结构进行阐明。鉴定出 8 种苦味化合物：阿考他林 A、阿考他林 C、5-(羟甲基)糠醛（HMF）、2,3-二氢-3,5-二羟基-6-甲基-4(H)-吡喃-4-酮（DDMP）、N-(1-去氧-d-果糖-1-基)-l-色氨酸（ARP）、色醇（TRO）、2-(2-甲酰基-5-(羟甲基-1H-吡咯-1-基)丁二酸（PBA）和色氨酸（TRP）。基于这些化合物的结构，支持了全麦面包中两种主要的苦味产生机制，即发酵和美拉德途径。
