Comprehensive analysis of phenolic compounds in four varieties of goji berries at different ripening stages by UPLC–MS/MS

Goji berries are highly appreciated by people because of their nutritional and economic value in recent years. A comprehensive analysis of phenolic compounds in four varieties of goji berries at four ripening stages (green skin, yellow-green skin, orange skin, completely red skin) was investigated. The contents of eleven representative phenolic compounds in goji berries were determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS). The rutin, isoquercitrin, and chlorogenic acid were the main phenolic components during goji berries fruit ripening, and their contents decreased with fruit ripening in four varieties. Among them, the rutin content of four varieties was the highest at the first ripening stage, ranging from 660.09 to 2617.61 μg g−1. The principal component analysis evidenced that ripeness and varieties were related to the amounts and compositions of phenolic compounds. Therefore, these results also provide referential information for further exploration and utilization of goji berries in food, pharmaceutical, or cosmetic industry.