GONÇALVES, A. L.; http://lattes.cnpq.br/1834220534365154; GONÇALVES, Alana de Lira.
Resumo:
This work consists in characterizing the pulp of yellom monbin fruit and in
determining some of its thermophysicaJ properties, such as specific bulk and heat, and
thermal diffusibility, and conduction, for those temperatures which are below freezing
point. The characterization of the yellom monbin pulp was accomplished by determining
some aspects, namely, pH, total soluble solids, acidity and moisture. The specific bulk was
obtained through the ratio between bulk and volume when freezing the samples of pulp in
a known volume bin at 0,-18, -35, -70, -100 and -180°C temperatures. The specific heat
below freezing point was measured by using Moline's method (MOLINE el al., 1961) at
temperatures o f - 3 5 , -70, -100 and -180°C, and also the mixture method at -18, -35, -70,
-100, -180 and -196°C. The thermal diffusibility was determined at the temperatures o f 0,
-18, -35, -70 and -100°C, using Dicherson's methodology (DICHERSON, 1965). The
thermal conduction was measured by the yield between specific bulk, specific heat and
thermal diffusibility. Some models from the literature, based on the water content for
specific heat measurements, were used. The resulting values were compared with the
experimental ones. From the results regarding the study on the pulp of yellom monbin, the
following conclusions were drawn: (a) the average values of pH, soluble solids, acidity and
moisture were approximately 4,16 pH, 8, 18° Brix, 1,23% and 90,06% (wet base),
respectively; (b) the specific bulk decreased from 1025 to 986 kg/m3 , together with a
decrease in temperature from 0°C to -180°C, describing an exponential curve, (c) the
specific heat obtained through Molines's methodology (MOLINE el al., 1961) ranged from
2,78 kj/kg°C to 3,81kj/kg°C for a temperature range of-35 to -180°C. These values are
higher than those reported by the literature, and also than the ones obtained from the
mixture method; (d) the specific heat in the yellom monbin pulp, obtained thorough the
mixture method, ranged from 1,96 kj/kg°C to 0,72 kj/kg°C, achieving a temperature range
from -18 to -196°C, respectively, thus describing a linear equation; (e) the thermal
diffusibility and conduction increased as temperature decreased where thermal diffusibility
values of 6,41xl0"7m2/s to 8,83"7m2/s were found for a temperature range of 0 -100°C. The
thermal conduction ranged from 1,43 w/m°C, for temperatures ranging from -18 to
-100°C.