No abstract

A detailed study was carried out with the postharvest mangoes (namely, the Langra and the Khirshapat) treated with different levels of Bavistin DF (BDF) solution (namely, 250, 500, and 750 ppm) for obtaining results on biochemical changes as well as storability of postharvest mango. The experiment was laid out in randomized complete block design with three replicates. The results of the experiments exhibited that only the single effect of varieties was found to be significant in most of the parameters studied. The Langra enriched a greater quantity of titratable acidity and total soluble solid (TSS) at 3rd day, over the Khirshapat. On the other hand, Khirshapat showed increased pulp pH and TSS at all the storage duration. The results explored that some physicochemical properties, namely, pulp pH, TSS, sugar (total, reducing, and nonreducing), and titratable acidity along with shelf life drastically decreased from untreated mangoes. Bavistin DF with the doses of 750 ppm showed better results in delaying the changes in physicochemical properties and extended shelf life.

Carrots accumulate phenols and often develop off-flavor and color after long periods of storage. To investigate probable causes for such physiological disorder, the effect of ethylene on various aspects of metabolism of carrot roots was studied. Ethylene, when applied at moderate level (100 ppm), caused an increase in total phenol content of the roots. It caused an increased accumulation of the phenols normally present in the tissue, especially isochlorogenic acid. Moreover, relatively longer exposure to a moderate level (100 ppm) and short exposure to high levels (2000 and 50,000 ppm) of ethylene induced formation of new compounds, viz, isocoumarin, eugenin, and two others yet unidentified. Studies with [1-14C]acetate, [2-14C]malonate and [3-14C]acetoacetate indicated that the newly synthesized compounds are probably synthesized via the acetate pathway. Ethylene stimulated the rate of O2 uptake and CO2 evolution by carrot slices, indicating probable relationship of glucose metabolism with de novo synthesis of “stress-metabolites”. Studies with specifically labelled glucose showed that both the Embden-Meyerhof-Parnas (EMP) and the Pentose Phosphate (PP) pathways operate in carrots, and that ethylene preferentially stimulated the EMP pathway. Like ethylene, dinitrophenol (DNP) induced isocoumarin synthesis in carrots. Methylene blue, an electron acceptor often used for stimulating glucose catabolism via the PP pathway, also induced isocoumarin synthesis in carrots. The effect of cycloheximide, an inhibitor of protein synthesis, suggested that the de novo synthesis of enzyme protein(s) might be required for ethylene-induced isocoumarin synthesis in carrots. In conclusion, it appears that ethylene triggers changes in the metabolism of carrots during storage, which result in, among other things, synthesis of so-called “stress-metabolites,” namely isocoumarin and eugenin and related compounds.

No abstract