Chair of Food Chemistry and Molecular and Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, D-85354 Freising, Germany.
Chair of Food Chemistry and Molecular and Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, D-85354 Freising, Germany.
Food Chem. 2022 Oct 30;392:133291. doi: 10.1016/j.foodchem.2022.133291. Epub 2022 May 23.
Fractionation of high molecular weight (HMW) coffee melanoidins of varying roasting intensity and evaluation of aroma binding activity via nuclear magnetic resonance spectroscopy revealed two fractions 5-10 kDa and > 50 kDa with high and selective binding affinity toward key coffee odorants. Quantification of monosaccharides, amino acids and phenolic acids, as well as aliphatic organic acids in hydrolysates of HMW material indicated the importance of aromatic residues in the form of hydroxycinnamic acids for the formation of non-covalent interactions with odorants. Caffeic acid concentrations were up to four times higher in fractions 5-10 kDa and > 50 kDa compared to 30-50 kDa and 10-30 kDa fractions. A minimization strategy was developed involving alkaline treatment of the most affine HMW fractions followed by reconstitution at typical coffee concentrations. These reconstituted HMW fractions exhibited up to 25% less aroma binding compared to native fractions of coffee.
通过核磁共振波谱法对不同烘焙强度的高分子量（HMW）咖啡类黑精进行分段，并评估其香气结合活性，结果表明，两个 5-10 kDa 和> 50 kDa 的分段具有对关键咖啡香气物质的高选择性结合亲和力。对 HMW 物质水解产物中单糖、氨基酸和酚酸以及脂肪族有机酸的定量分析表明，以羟基肉桂酸形式存在的芳香残基对于与香气物质形成非共价相互作用非常重要。与 30-50 kDa 和 10-30 kDa 分段相比，5-10 kDa 和> 50 kDa 分段中咖啡酸的浓度高达 4 倍。开发了一种最小化策略，涉及最亲和的 HMW 分段的碱性处理，然后在典型的咖啡浓度下再构成。与咖啡的天然分级相比，这些再构成的 HMW 分级的香气结合能力降低了 25%。
