Chemical composition and nutritional potential of yam bean seeds (Pachyrhizus erosus L. urban)

The Bioactivity and Phytochemicals of Pachyrhizus erosus (L.) Urb.: A Multifunctional Underutilized Crop Plant

Pachyrhizus erosus (L.) Urb. is an underutilized crop plant belonging to the Fabaceae family. In recent years, the plant received huge attention and was introduced in different countries owing to properties such as a high nutritional content, its nitrogen-fixing abilities, and different biological activities such as its antioxidant, immune modulation, anticancer, anti-diabetes, anti-osteoporosis, antiviral, and antiaging affects, among others. In this review, an attempt has been made to comprehensively compile the biological activities of the plant to provide a panoramic view of the current efforts and further directions, which may lead to the development of pharmacological applications. This information will be helpful in creating interest towards P. erosus and it may be useful in developing the plant for medical applications and/or as a functional food. More than 50 phytochemicals have been reported from the plant, which belong to different chemical classes such as triterpenoids, organic acid, flavonoids, and fatty acids. Numerous biological activities were reported from the plant through in vivo, in vitro, ex vivo, and human studies. However, well-defined clinical studies are still lacking for the establishment of any biological properties that could be further developed. Suggestions for the further development of P. erosus, according to current knowledge about the different biological properties, has also been provided.

Fast method for the simultaneous quantification of toxic polyphenols applied to the selection of genotypes of yam bean (Pachyrhizus sp.) seeds

The purpose of the research was to develop and validate a rapid quantification method able to screen many samples of yam bean seeds to determine the content of two toxic polyphenols, namely pachyrrhizine and rotenone. The analytical procedure described is based on the use of an internal standard (dihydrorotenone) and is divided in three steps: microwave assisted extraction, purification by solid phase extraction and assay by ultra high performance liquid chromatography (UHPLC). Each step was included in the validation protocol and the accuracy profiles methodology was used to fully validate the method. The method was fully validated between 0.25 mg and 5 mg pachyrrhizin per gram of seeds and between 0.58 mg/g and 4 mg/g for rotenone. More than one hundred samples from different accessions, locations of growth and harvest dates were screened. Pachyrrhizine concentrations ranged from 3.29 mg/g to lower than 0.25 mg/g while rotenone concentrations ranged from 3.53 mg/g to lower than 0.58 mg/g. This screening along with principal component analysis (PCA) and discriminant analysis (DA) analyses allowed the selection of the more interesting genotypes in terms of low concentrations of these two toxic polyphenols.

Degradation of rotenone in yam bean seeds ( Pachyrhizus sp.) through food processing

The purpose of this research is to screen different processes that could potentially decrease or even eliminate rotenone, a toxic isoflavonoid, from Pachyrhizus seeds. Yam bean seeds have very interesting nutritional characteristics, especially their high protein and lipid contents, and could potentially increase food security in under-nourished populations. However, they contain rotenone, a natural molecule previously used as an insecticide inhibiting the respiratory mitochondrial chain. It was also proven to be toxic to mammals as chronic exposure leads to the development of Parkinson-like symptoms in rats. As the thermosensitivity of rotenone had been reported, this study tested different processes (drying, roasting, boiling, frying, alcohol extraction), tegument removal, and traditional Beninese culinary recipes. Rotenone was then quantified in end-products by a validated method, associating microwave extraction, solid phase extraction (SPE), and HPLC-UV. With these processes a rotenone removal of up to 80% was obtained. The most effective methods were the drying and roasting of the seeds and the maceration of their flour in local alcohol. Rotenone degradation and elimination were confirmed by cytotoxic assays, effectively inducing a decrease in sample toxicity.