Kinetika fermentativnykh reaktsiy osennikh sortov yablok pri kholodil'nom khranenii s primeneniem trekovykh membran

The article gives the results of a study of the influence of an oxygen reduced concentration and a carbon dioxide increased concentration at cold storage of apples of autumn variety on the activity of terminal oxydases, involved in the regulation of physiological and biochemical processes at the final stages of oxidation of respiration substrates. The aim of the research is to study the change of the activity of terminal oxidases depending on the cold storage duration in the gaseous atmosphere with reduced oxygen concentration and increased carbon dioxide concentration formed by a biological method using gas selective track membranes. The test subjects were the apples of autumn varieties Grushovka Yudicheva, Kordonovka and Pepin Shafranny, grown according to the generally accepted technology in the garden of collection trees of the Pavlovskaya experimental station of the N.I. Vavilov VNIIR. To form a gaseous atmosphere during the storage of autumn variety apples a new composite membrane was used, it consisted of a substrate based on the polyethylene terephthalate (PET) track membranes (TM) and a selective layer based on the organosilicon block copolymer (pore diameter 0,2 µm, selectivity 5,0). This membrane was developed in laboratories of the A.F. Ioffe PhysicalTechnical Institute and S.V. Lebedev NIISK. It was shown that during storage the change of the terminal oxidase activity depended on the apple variety, storage duration, gas composition and enzyme type. The kinetic dependences of changes in the activity of phenol oxidase, peroxidase, and catalyse enzymes on the storage duration of autumn apple varieties Grushovka Yudicheva, Kordonovka and Pepin Shafranny in the normal atmosphere (NA) and controlled atmosphere (CA) were revealed. The regression equations characterizing these dependences were obtained. The velocity constants of inactivation reactions of the enzymes studied during storage of autumn varieties in NA and CA were determined. It was established that the activity of the enzymes of phenol oxidase, peroxidase, and catalyse decreased when storing apples in CA with reduced oxygen concentration (up to 5,2±0,1%) and with increased carbon dioxide concentration (up to 3,6±0,1%) decreased. The velocity constants of enzyme inactivation reactions decreased 1,15-1,77 times depending on the variety and enzyme type. It was shown that when the apples adapted to the positive low temperature and the modified gas composition, then the terminal oxidases performed the regulatory function.

controlled atmosphere (CA), gas selective track membrane (GSTM), apples, cold storage, terminal oxidases, enzymatic reactions, kinetics