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Treatment of barley endosperm with gibberellic acid stimulates the production of many hydroiytic enzymes and the release of sugars, polypeptides and inorganic phosphate into the culture medium, the endosperm of the treated preparations frequently disaggregating completely. The gibberellic acid appears to function by stimulating the living aleurone layer to synthesize enzymes de novo, rather than by activating preformed enzyme precursors throughout the endosperm.

Ferulic acid esterase activity was detected in extracts of barley malt using an assay employing a novel artificial substrate, mono-feruloyl glycerol. Mono-feruloyl glycerol has been synthesized and analysed to determine its degree of substitution and purity. It consists of a mixture of the two isomers 1-feruloyl glycerol and 2-feruloyl glycerol. The extraction offerulic acid esterase and its assay conditions have been optimised. The presence of both a detergent and reduced glutathione in the extraction medium increased the amount of enzyme extracted. ApH of 7.5 was optimal for enzyme activity. The enzyme in solution was only stable up to 30°C. The crude extract containing the enzyme releasedfree ferulic acidfrom both soluble and insoluble cell wall materials. After extraction of the soluble enzyme, insoluble enzyme, capable of releasing free ferulic acid from feruloyl glycerol, was detected in the residual grain solids.

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