Hemp flour, from waste to nutritional and nutraceuticals reuse

Abstract

One of the main objectives of recent years is to characterize and valorize by-products of agri-food industries, as new sources of bioactive components, from the perspective of a circular economy and a biorefinery approach both for environmental and economic reasons. Hemp flour, obtained from Cannabis sativa seeds, is an example of promising bio-sustainability raw material with a high nutritional value that can be obtained from industrial by-products. From C. sativa seeds is obtained an oil rich in fatty acids, mainly linoleic and α-linolenic acids [1]. After oil extraction, seeds can be ground to obtain edible flour. Foods fortified with these “non-wheat flours” would have an additional supply of fiber, minerals, proteins, and polyphenols, thus increasing the final product’s nutritional and beneficial properties. The objective of this work was to study chemical qualities (polyphenolic profile, amino acids, total phenolic content (TPC), antiradical capacity and fatty acids) of hemp flour, for the possible preparation of functional foods. The phenolic profile, determined by UHPLC- ESI/QTOF-MS, showed a greater presence of bound phenols compared to the free ones [2]. Bound phenolic, are covalently bound to cell wall structural components and rod-shaped structural proteins, and in addition to their antioxidant activity, have important effects on the growth inhibition of cancer cells, and in the regulation of the microbiota [3]. The main free phenolic component highlighted was cannaflavin C and the main bound phenolic components were protocatechuic acid, caffeic acid, hydroxycinnamic acid and cannaflavin C. Among the amino acids, hemp flour contains a high presence essential aminoacids (15.9 g/100g). Gliadin and glutenin are completely absent, for this reason, hemp flour is suitable for people with celiac disease. High values of TPC and antiradical activity have been also highlighted. Although the hemp seeds were previously subjected to oil extraction, hemp flours retain about 8% of oil, and the fatty acids present in the largest amount were linoleic acid (53.6%) followed by α-linolenic acid (15.5%) denoting a high nutritional level.