REQUIMTE/LAQV, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R. J. Viterbo, 4050-313 Porto, Portugal.
REQUIMTE/LAQV, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R. J. Viterbo, 4050-313 Porto, Portugal.
Food Chem. 2020 Oct 1;326:126940. doi: 10.1016/j.foodchem.2020.126940. Epub 2020 Apr 30.
Silverskin, the main coffee roasting by-product, is rich in fiber, protein and antioxidants. Its protein fraction was studied regarding total, protein and non-protein nitrogen content. Amino acids were analysed after automated on-line derivatization. The method showed to be precise (<6.9%) and accurate (recoveries using a certified reference material and spiked blanks: 90-102%; for spiked samples: 73-113%). The real protein content of silverskin was 12%. One quarter of the total nitrogen corresponded to the non-protein fraction. All essential amino acids were present in the free form, except methionine. Regarding total amino acids, aspartic and glutamic acids (9-10 mg/g) were the major compounds. Branched chain amino acids (leucine, isoleucine and valine) were also present in substantial amounts (5-8 mg/g), as well as proline and arginine (~5 mg/g). Concluding, silverskin is a source of amino acids with relevance for the improvement of cognitive and physical performances.
银皮是主要的咖啡烘焙副产物，富含纤维、蛋白质和抗氧化剂。本研究对其蛋白质部分的总氮、蛋白质氮和非蛋白氮含量进行了分析。采用自动在线衍生化后分析了氨基酸。该方法具有较高的精密度（<6.9%）和准确度（使用有证标准物质和加标空白的回收率：90-102%；加标样品的回收率：73-113%）。银皮的实际蛋白质含量为 12%。四分之一的总氮对应于非蛋白部分。除蛋氨酸外，所有必需氨基酸均以游离形式存在。就总氨基酸而言，天冬氨酸和谷氨酸（9-10mg/g）是主要化合物。支链氨基酸（亮氨酸、异亮氨酸和缬氨酸）的含量也相当高（5-8mg/g），脯氨酸和精氨酸的含量约为 5mg/g。综上所述，银皮是氨基酸的来源，对改善认知和身体机能有重要作用。
