Biochemical studies with garlic (Allium sativum) cell cultures showing different flavour levels

Garlic (Alliurn sativurn L) cell cultures, unorganised white as well as organised green callus, revealed a total oxfive amino acidprecursors (methyl, propyl, allyl, cysteine sulphoxides) and two unidentlfied ninhydrin-positive compounds, All the,five compounds were hydrolysable by alliin lyase to yield pyruvic acid. Their relative concentration varied in the cultured systems and the explant. The totaljlavour substrate index in globular white callus and semi-diferentiated green callus was 4 and 13% respectively of the original explant. In contrast to the substrate levels, the speciJic activity of alliin lyase enzyme showed hay the original activity of the garlic bulb explant. The relationship between intermediary metabolism and flavour formation was studied in these cultures with the help of 14C-glucose and I4C-rnethionine. The incorporation of I4C label was lower in the protein, carbohydrate and lipid fractions with a concomitant higher incorporation in the volatile fraction of semi-diferentiated cultures, whereas this trend was reversed in the white globular callus. 14C Conversion to thejlavour fraction was much lower in the in-vitro cultures when compared with the garlic bulb. The actiuity of some enzymes such as amino transferase, malate dehydrogenase, polyphenol oxidase, peroxidase, and alkaline phosphatase was higher in the cultured cells than in garlic bulb. There were diferences also in the protein, free amino acid projiles and peroxiduse isozymes of garlic cell cultures and the original explant.