FIRMNESS AND THERMAL CONDUCTIVITY OF RED BEETS IN STORAGE

Abstract

ABSTRACTFirmness and thermal conductivity of “Detroit Dark Red, Ferry's Strain” and “Ruby Queen” beets were determined after storage at: 0°C, 95% relative humidity (RH); 12.8°C, 24% RH, and 1.7°C, uncontrolled humidity. Firmness at fixed temperature and humidity conditions decreased with storage; it could be described by a first order rate equation. At a fixed temperature (1.7°C) and uncontrolled humidity, magnitudes of firmness varied as the humidity varied; in contrast, thermal conductivity was influenced very little. At 0°C and 95% rel. humidity, thermal conductivity remained essentially constant for four weeks. The magnitude of thermal conductivity, at room temperature and on the day of harvest, was about the same for four different varieties of beets; “King Red,”“Detroit Dark Red, Ferry's Strain,”“Ruby Queen,” and “Detroit Dark Red, Morse's Strain;” it ranged between 0.579 and 0.600 W/m °K.