Protein content and amino acids profile in 10 cultivars of ginkgo (Ginkgo biloba L.) nut from China

As a traditional food and medicine source, ginkgo (Ginkgo biloba L.) nut is popularly consumed in East Asia. The aim of this work is to characterize protein content and amino acids profile in 10 ginkgo nut cultivars, named successively as no. 1 to no. 10. There were observed differences among the cultivars with respect to the contents of protein and amino acids, except Cys. The no. 6 cultivar presented the highest protein content (22.1 g/100 g DW), while the no. 9 had the lowest (16.2 g/100 g DW). The contents of EAA and NEAA were revealed to vary in the range of 14.3–26.2 and 21.4–41.1 g/100 g protein, respectively. The most abundant EAA was Leu, and the first limiting amino acid was Lys. The level of Arg was attractive, especially in the no. 5 cultivar (1741 mg/100 g DW) where it is comparable to hazelnut and pistachio. As confirmed by AAS and EAAI, the no. 5 cultivar presented the best amino acids profile and protein quality among these cultivars. These results have relevance to the scientific development and application of ginkgo nuts in the food industry.