Abrasive milling: A method to pre-fractionate testa and embryonic axis from yellow pea

Abstract Making use of crops structural break-up during pearling and subsequent fractionation into starch or protein enriched fractions was investigated using stepwise pearling as a method. In first instance, pearling resulted in separation of pea testa and embryonic axis from the cotyledon. Further around 20% of the yellow pea cotyledon was pearled off and collected separately from the inner kernel. All four fractions were finely ground and their composition analysed. Due to the di-cotyledon structure of the pea, solely pearling the outer kernel couldn't be guaranteed. Therefore, the process was repeated by hand-dissection, to ensure only separation of the outer 20% cotyledon. Pearling resulted in size reduction and separation of testa, embryonic axis and the outer and inner part of the cotyledon. Although, no considerable enrichment was achieved in protein or starch content in the pearled fraction of the outer and inner cotyledon, pearling gave the opportunity to obtain the testa fraction, which according to literature is rich in dietary fibre. Moreover, the protein-rich embryonic axis was separated and collected. The testa fraction accounts for 7–8% of the whole pea and contains little protein and starch, which makes it a promising dietary fibre rich ingredient in food application.