Associate Professor Delaware State University Dover, Delaware, United States
Abstract: Hemp seed flours are valuable sources of protein and bioactive compounds. This study aimed to evaluate the effect of non-thermal processing methods such as milling, germination, isoelectric precipitation (IEP), and enzyme assisted extraction (EAE) on the nutritional content, physicochemical and bioactive properties of hemp seed flours. The protein and oil content of the untreated/milled, germinated, IEP, protease- and pronase-treated flours were in the ranged of 22.71 - 89.94% and 31.00 - 31.44%, respectively. Higher amount of protein was extracted using IEP compared to protease- and pronase-treated seeds. While all the processing methods reduced trypsin inhibitor content in the hemp seed flours, only germination and IEP reduced phytic acid and tannin content. Germination, IEP and EAE improved the in vitro digestibility of the flours. γ-tocopherol, lutein, zeaxanthin, α- and β-carotene were determined in the milled and germinated flours. About 7 - 14 mg/g total phenolic content, 1 - 2 mg Rutin/g extract, 43 - 121 mM TEAC/g were determined in the flours. The germinated flour exhibited greater (IC50 values of 8.02) DPPH radical-scavenging activity than the other flours. Overall, hemp seed flours with diverse properties could be produced by milling, germination, IEP and EAE. These minimally processed, non-thermally produced flours can be used as alternate ingredients in food formulation and product development applications and reduce the dependence on the few conventional plant-sourced materials while adding value to hemp seed, increasingly being produced in the United States following declassification.
