Kinetics of polygalacturonase activity and firmness of peaches during storage

The activity of endo-polygacturonase (PG) in peaches during storage at different constant temperatures is shown to be the result of a formation from some inactive predecessor and a denaturation or decay into an inactive form. This whole process strongly resembles the normally encountered turnover. On these premises, a process-oriented mathematical model is formulated. The variance accounted for by the model in multivariate nonlinear regression analysis is more than 80% for the data gathered in two successive seasons. Analysis of the data from both seasons combined did not decrease the descriptive power of the model, regardless the fact that the maturity at harvest and the initial level of enzyme activity showed major differences. The values of the parameters obtained from the data of both seasons combined were comparable with those of the individual seasons. The effect of the action of PG on the firmness of peaches was also modelled and analysed with an variance accounted for of almost 90%. The parameters obtained with respect to denaturation of the enzyme were highly comparable.

[1]  R. Scorza,et al.  CHANGES IN THE PHYSICO-CHEMICAL PROPERTIES OF PEACH FRUIT PECTIN DURING ON-TREE RIPENING AND STORAGE , 1993 .

[2]  J. Ray,et al.  Antisense RNA inhibition of polygalacturonase gene expression in transgenic tomatoes , 1988, Nature.

[3]  O. T. Villiers,et al.  Physiological changes associated with the development of woolliness in ‘Peregrine’ peaches during low-temperature storage , 1988 .

[4]  J. Whitaker.  Principles of Enzymology for the Food Sciences , 2018 .

[5]  A. L. Shewfelt,et al.  TEXTURAL CHANGES AND MOLECULAR CHARACTERISTICS OF PECTIC CONSTITUENTS IN RIPENING PEACHES , 1971 .

[6]  K. Gross.  A rapid and sensitive spectrophotometric method for assaying polygalacturonase using 2-cyanoacetamide [Tomato, fruit softening] , 1982 .

[7]  J. Bruinsma,et al.  Conversion of the polygalacturonase isoenzymes from ripening tomato fruits , 1988 .

[8]  I. H. Segel.  Enzyme Kinetics: Behavior and Analysis of Rapid Equilibrium and Steady-State Enzyme Systems , 1975 .

[9]  G. Hobson.  The Firmness of Tomato Fruit in Relation to Polygalacturonase Activity , 1965 .

[10]  A. Goldlust,et al.  Control by ethylene of arginine decarboxylase activity in pea seedlings and its implication for hormonal regulation of plant growth. , 1985, Plant physiology.

[11]  C. N. Thai,et al.  Peach quality changes at different constant storage temperatures: empirical models. , 1990 .

[12]  J. Giovannoni,et al.  Expression of a chimeric polygalacturonase gene in transgenic rin (ripening inhibitor) tomato fruit results in polyuronide degradation but not fruit softening. , 1989, The Plant cell.

[13]  A. Voragen,et al.  The significance of endogenous and exogenous pectic enzymes in fruit and vegetable processing. , 1991 .

[14]  A. L. Shewfelt.  Changes and Variations in the Pectic Constitution of Ripening Peaches as Related to Product Firmness , 1965 .

[15]  R. Pressey,et al.  DIFFERENCE IN POLYGALACTURONASE COMPOSITION OF CLINGSTONE AND FREESTONE PEACHES , 1978 .

[16]  R. Young,et al.  Postharvest Variation in Cellulase, Polygalacturonase, and Pectinmethylesterase in Avocado (Persea americana Mill, cv. Fuerte) Fruits in Relation to Respiration and Ethylene Production. , 1979, Plant physiology.

[17]  Larry Boersma,et al.  The arrhenius equation as a model for explaining plant responses to temperature and water stresses , 1990 .

[18]  B. Wilkenson.  Some Effects of Storage Under Different Conditions of Humidity on the Physical Properties of Apples , 1965 .

[19]  R. Pressey,et al.  CELLULASE ACTIVITY IN PEACHES DURING RIPENING , 1974 .

[20]  R. Ben-arie,et al.  Pectolytic enzyme activity involved in woolly breakdown of stored peaches. , 1980 .