01534nam a2200181 a 450000100080000000500110000800800410001910000180006024500600007826000210013850000950015952010110025465300100126565300210127565300280129665300120132465300160133610116462014-04-16       1977    bl uuuu  m   00u1 u    #d1 aWERNER, R. A.  aChanges in peach firmness as influenced by temperature.  a1977. 42f.c1977  aDissertação (Master of Science)- School of Rutgers University, New Brunswick, USA, 1977.  aPost harvest softening in peaches at warm temperatures occurs rapidly (2 to 3 days), and is accompanied by the increase in water-soluble pectin fraction. Soft peaches rehardened when returned to low temperatures. The process occurred in air and also in nitrogen atmosphere. The rehardening in air or in nitrogen was not accompanied by changes in pectic substances. The phenomenon is apparently non-metabolic, and caused by the effect of the temperature on gelling properties of pectin fractions. Rapid temperature changes in the fruit pulp, induced by hydrocooling or warming, led to corresponding rapid rehardening and softening, respectively. Similary decrease in temperature led to the increase in the viscosity of a fruit pectin extract and tissue homogenate while the increase in temperature resulted in a decrease in the viscosity of these solutions. Collectively, the data suggest that the temperature-induced changes in fruit firmness reflect the gelling response of the pectic fraction in tissues.  aCLIMA  aFIRMEZA DA POLPA  aFISIOLOGIA POS-COLHEITA  aPESSEGO  aTEMPERATURA