Biochemical studies on internal breakdown - a ripening disorder in mango fruits Selvaraj Y., Edward Raja M., Rawal R.D. Indian Institute of Horticultural Research, Hessaraghatta, Bangalore 560 089 Summary Affected ripe fruit tissues separated into spongy, tissues surrounding spongy and healthy tissues were analysed. The breakdown tissue had low total carotene, sugars, sucrose, sugar: acid ratio, K, Ca, Na and higher acidity, glucose: fructose ratio, N, P, Mg, Zn and Fe contents as compared to healthy tissue. Eleven non-volatile organic acids were identified and quantified by GC analysis, namely pyruvic, succinic, fumaric, oxalo-acetic, malic, α-ketoglutaric, malonic, glyoxylic, glutamic, tartaric and citric acids. Breakdown tissue had twice the amount of citric and half the quantity of malic acid as compared to healthy tissue. Glycolytic enzymes, hexokinase, PK and PFK and gluconeogenic enzymes, FBPase and PEPCK activities were low in breakdown tissue. The ethylene forming enzyme activity was 3-fold lower in breakdown tissues. Top |