Antioxidant Activity of Malt Rootlet Extracts

Abstract

To improve the malt rootlet value, the antioxidant potentialities of this byproduct of the malting industry have been analyzed. Three extracts have been considered from the points of view of dry matter yield, level of antioxidant compounds, and efficiency and cost of the extraction protocols. They respectively contain rootlet oil, free phenolic compounds, and bound phenolic compounds. The rootlet oil contains only a low quantity of tocopherols (respectively, 20.6 and 4.2 microgram of alpha-tocopherol and gamma-tocopherol per gram of dry rootlets), and a weak antioxidant activity, evaluated in a stripped corn oil by following spectrophotometrically the conjugated dienes, has been pointed out. The bound compound extract presents a good antioxidant power mainly due to the presence of trans-ferulic and trans-p-coumaric acids, but the dry matter yield is low (2%). The free compound extract has a good antioxidant power, and the valuable dry matter, mainly composed of proteins (52%), sugars (33%), and reducing compounds (5.5%), has a yield of 12%. The mixing of bound and free compound extracts presents an antagonistic effect on the antioxidant power, but a synergistic effect has been pointed out for the mixing of alpha-tocopherol and free compound extract.

Relationship between antioxidant properties and chemical composition of some Thai plants

“…It has been reported in previous investigations that high yields of extract from some plants contained high levels of phenolic compounds and antioxidant properties (Guillen and Manzanos, 1996;Lehtinen and Laakso, 1998;Borneley and Peyrat-Maillard, 2000). This was not found in the present investigation especially for several types of plants studied.…”

Antioxidants in fruits and vegetables - the millennium's health

“…A number of plant constituents have been recognized to have positive eects when tested against the oxygen reactive compounds in biological systems. Many plant by-products such as peanut hulls, carob seeds, citrus peels and seeds and malt root extracts have also been exploited for their antioxidative potentials (Bocco et al, 1998;Bonnely et al, 2000). Thus the natural antioxidants present in foods and other biological materials have attracted considerable interest because of their presumed safety and potential nutritional and therapeutic eects (Steinberg, 1991;Ames et al, 1993).…”

Antioxidants in fruits and vegetables – the millennium’s health

“…A number of plant constituents have been recognized to have positive effects when tested against the oxygen reactive compounds in biological systems. Many plant by‐products such as peanut hulls, carob seeds, citrus peels and seeds and malt root extracts have also been exploited for their antioxidative potentials (Bocco et al ., 1998; Bonnely et al ., 2000). Thus the natural antioxidants present in foods and other biological materials have attracted considerable interest because of their presumed safety and potential nutritional and therapeutic effects (Steinberg, 1991; Ames et al ., 1993).…”