Comparing the Effectiveness of Three Different Biorefinery Processes at Recovering Bioactive Products from Hemp (Cannabis sativa L.) Byproduct

Abstract

Hemp (Cannabis sativa L.) seeds are considered a nutritional powerhouse, rich in proteins and unsaturated fatty acids. The market for hemp seed food products is growing, due to the loosening of constraints in industrial cultivation. During the food processing chain, the external part of the seed is discarded, although it contains a significant amount of proteins. Converting this material into value-added products with a biorefinery approach could meet the ever-increasing need for sustainable protein sources while reducing food waste. In this study, creating value from hemp byproducts was pursued with three different approaches: (i) chemical extraction followed by enzymatic digestion, (ii) liquid fermentation by strains of Lactobacillus spp., and (iii) solid-state fermentation by Pleurotus ostreatus. The resulting products exhibited a range of in vitro antioxidant and antihypertensive activity, depending on the proteases used for enzymatic digestion, the bacterial strain, and the length of time of the two fermentation processes. These byproducts could be exploited as functional ingredients in the food, pharmaceutical, and cosmetic industries; the suggested biorefinery processes thus represent potential solutions for the development of other protein-containing byproducts or wastes.

Antioxidant and Angiotensin I-Converting Enzyme (ACE) Inhibitory Peptides Obtained from Alcalase Protein Hydrolysate Fractions of Hemp (Cannabis sativa L.) Bran

“… 25 The antihypertensive activity was particularly impressive: the IC 50 values for ACE inhibition of bioprocessed samples were similar to those in protein hydrolysates from the whole hemp seed. 25 To identify the peptides responsible for the bioactivity detected in bioprocessed HPB, the byproduct was hydrolyzed by Alcalase and divided by membrane ultrafiltration into four fractions of different molecular weights (MWs). The ability of protein-derived bioactive peptides to exert their activity is strictly dependent on their structure.…”

“…The HPBPE was first dissolved in deionized water (12.5%, w/v) and hydrolyzed with Alcalase 2% (v/v) at pH 8 for 2 h at 50 °C, as previously reported for the same substrate. 25 The enzyme was inactivated, stopping the reaction, by heating the HPBPE to 85 °C for 15 min. After cooling to room temperature, the solution was centrifuged (14,000 g , 20 min, 4 °C).…”

“…The ARSA was determined by following the procedure reported by Setti et al 25 The ABTS stock solution (7 mM in 2.45 mM K 2 S 2 O 8 ) was diluted using sodium acetate (20 mM, pH 4.5) until an absorbance of 0.70 ± 0.02 at 734 nm was achieved. Then, 198 μL of this solution mixed with 2 μL of the sample was incubated in the dark at room temperature for 30 min.…”

“…The DRSA was also determined using the method of Setti et al 25 A 20 μL aliquot of the sample was mixed with 180 μL of 50 μM DPPH solution in methanol. After the mixture was incubated in the dark at room temperature for 30 min, the absorbance was measured at 517 nm.…”

“…The ferrous ion-chelating activity was also measured according to the method of Setti et al, 25 with slight modifications. The sample (25 μL) was mixed with 100 μL of 300 μM ferrozine and 100 μL of 50 μM FeSO 4 and incubated at room temperature for 10 min.…”