Organic Acids in the Ripening Banana Fruit.

The nonvolatile orgainic acicls uncloubte(dly play a role in fruit ripening as they (1o in many other metabolic processes. As an approach to definiing this role in the banania fruit, informatioin is needled on the nature of these acids and on the chainges which occur dluring ripening. Earlier reports (23) indicate the presence of nmalic, citric, oxalic, an(l tartaric acids in the banana fruit, with malic acid being the princil)al acidl. Lulla and Johar (13) found only mlalic and( citric acids in 9 varieties of bananas froml India. WN'olf (25 ) found the same 2 acids plus an unknow\n fraction in Colombian bananas. SteNard et al. (20) have recently reporte(l the presence of 30 organic acids in alcoholic extracts of the banana fruit. Mialic ain(l citric aci(ds were predlominant; the other acidls occurre(l in trace amounts. These workers also (letecte(l 22 keto acids by extraction of the phenylhydrazonies. There is little quantitative information available oIn the organic acids in bananas or on the changes wvhich occur during ripening. The mlalic acid concentration has been reported to vary betw\een 0.8 and 7.5 me( 1(00 g fresh weight (23) anid( to increase three to sevenfold during ripening (2, 8). Pyruvic, a-ketoglutaric, and oxaloacetic acidls also increase (lurinlg the ripening (2). The present studly wN-as un(lertakein to confirnm the i(lentity, of the nonvolatile organic acidls of the banana fruit andl to dletermine the concentration of these acids througlhout ripening.