Protein composition and nutritional evaluation of three Polygonatum Mill species: A comparative analysis

<i>Polygonatum</i> Mill. (Asparagaceae) is an edible crop with great potential for development in China. This study focused on the analysis of protein components from <i>Polygonatum kingianum</i> Coll. et Hemsl (DHJ), <i>P. cyrtonema</i> Hua (DHHJ), and <i>P. sibiricum</i> Red (HJ). DHJ exhibited the lowest protein content (83.2 mg/g), the highest essential AA rate (23.6 %), the highest degree of protein hydrolysis (13.5 %), and the highest PDCAAS (0.57). DHHJ had the highest protein contents (189.8 mg/g), the lowest rate of essential AA (21.6 %), the lowest degree of protein hydrolysis (10.8 %), and the lowest PDCAAS (0.42). The first limiting AA was found to be Lys for DHHJ and Lys/Leu for DHJ and HJ. 96 carbohydrate, 61 amino acid, and 83 energy metabolism-related differential proteins were identified. Protein A0A5P1F9I9 and Q5EER7 were highly related to the digestive and nutritional properties. This study could provide an essential reference for better utilizing the <i>Polygonatum</i> protein component.