Title : Nutritional potential and fermentation properties of edible Heinsia crinite, Piper guineense and Xylopia aethiopica from Angola
Abstract:
The medicinal and edible plants from Angola, Heinsia crinita (H. critina), Piper guineense (P. guineense) and Xylopia aethiopica (X. aethiopica) generally sold at the local African market to treat malaria or for women´s health. Few information is known about the composition that causes the activities to combat these illness. For this reason, the objective of the present work was to obtain a comprehensive nutritional characterization of H. critina root, P. guineense seed and X. aethiopica pod. Results showed the nutrient and elemental composition of these plants varies significantly, with the H. critina root containing abundant carbohydrates (32.74%), while the P. guineense seed and X. aethiopica pod are rich in proteins (12.52%) and lipids (29.99%), respectively. The highest concentrations of essential amino acids (EAAs) were leucine, with the limiting types being methionine, cysteine and valine, among that H. crinita root had the highest EAAs (39.45%). As for their fatty acids, oleic acid (C18:1n9) and linoleic acid (C18:2n6) were the major monounsaturated and polyunsaturated fatty acids (MUFAs, PUFAs), respectively, while C24:1n9 was found only in the P. guineense seed. All plants are particularly rich in potassium (K), while zinc (Zn) and iron (Fe) are the main microminerals. In addition, UPLC-ESI-TSQ-MS/MS was used to identify and quantify phenolic profile of these plants. There were some major flavonoids, such as luteolin, kaempferol, isorhamnetin, apigenin and quercitrin, but most of them were in the form of glycosides. Three types of chemometrics methodologies: hierarchical cluster analysis (HCA), principal components analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLC-DA) were used to differentially analyze phenolic compounds in these plants, with an attempt to discover and excavate structurally novel and biologically active phenolics from them. As for antioxidant capability, the X. aethiopica pod showed the best level in 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reducing (FRAP) and trolox equivalent (TEAC). Correlation coefficient analysis demonstrated that phenolic acid type showed significant positive correlation with DPPH and FRAP, while quercetin and luteolin flavonoids showed significant positive correlation with TEAC. Based on the fact that biotransformation is a viable strategy to enhance bioactivity, their fermentation characteristics and bioactivity were evaluated by solid state fermentation technology of Aspergillus niger. This strategy increased their free phenolic content as well as antioxidant activity. To conclude, the data obtained will help optimize the use of these resources and promote their broader application in food flavors, pharmaceuticals, cosmetics, and other related fields, enhancing their commercialization potential.
