Nutritional and chemical profiling of UK-grown potato bean (Apios americana Medik) reveal its potential for diet biodiversification and revalorisation

Apios americana Medik, a native American plant has potential as a commercially viable Northern European-grown rootcrop, mainly due to its resistance to extreme climate and nutritional quality. Analysis of A. americana sourced from two UK sites; South (51.4690° N, 1.1150° W) and North (55.9661° N, 3.2063° W) showed that the tubers were a complete source of amino acids (UPLC-TUV analysis), were rich in protein (15.0±0.0160 and 17.3±0.0779%; Vario Max CN analysis), fibre (total non-starch polysaccharides, 10.4±0.570 and 10.6±0.280%; GC analysis) and micronutrients (calcium, manganese, iron, zinc, molybdenum, potassium and phosphorus; ICP-MS analysis). Apios americana tubers were also rich in bioactive phytochemicals. From the 156 plant metabolites measured using LC-MS/MS analysis, genistein was the major phytophenol in both the Southern- and Northern UK tubers (259±12.2 mg Kg-1 and 356±29.9 mg Kg-1 respectively); the peel having similar phytochemical profiles. The protein and fibre content of the leaves (17.3±0.0434% and 11.7±0.0445%) and rhizomes (18.4±0.0152% and 13.5±0.590%) were significantly higher (p<0.05) than the tubers. The leaves were also a good source of anthocyanins; delphinidin and cyanidin (840±137 and 3934±176 mg Kg-1respectively). Cultivation of A. americana as a high-protein staple-crop has enormous potential in Northern European countries for human nutrition, diet diversification, and use in livestock diets.