[Thermal resistance of yeasts in orange juice at different concentrations of soluble solids].
Thermal decimal reduction time (D) of Rhodotorula rubra (R. rubra) and Candida intermedia (C. intermedia) at 63, 64, 65, 66 and 67 degrees C was studied, at soluble solids concentrations of 12, 36 and 52 degrees Brix in orange juice. Experiments were conducted according to Stumbo method. D values for R. rubra were obtained in a range of 3.1 s for D 67 degrees C at 36 degrees Brix as a minimum to 209 s at 64 degrees C and 52 degrees Brix as a maximum. For C. intermedia, the minimum D value was 3.2 s at 64 degrees C and 12 degrees Brix and the maximum was 6 s at 64 degrees C and 52 degrees Brix. It can be noticed that as the concentration of soluble solids increases, the thermal resistance of the yeasts increases. R. rubra exhibits its highest thermal resistance at 52 degrees Brix for all temperatures. C. intermedia shows more osmotolerancy that R. rubra but it is more sensitive to heat at high sugar concentrations.
Medina de Salcedo
Z
Z
Laboratorio de Alimentos, Departamento de Química, Facultad Experimental de Ciencias, La Universidad del Zulia, Maracaibo, Venezuela.
Sulbarán de Ferrer
B
B
Ferrer Ocando
A
A
Ojeda de Rodríguez
G
G
D001628:Beverages / Q000382:microbiology*; D002175:Candida / Q000502:physiology*; D002957:Citrus / Q000382:microbiology*; D015169:Colony Count, Microbial; D005511:Food Handling; D005516:Food Microbiology; D006358:Hot Temperature; D011786:Quality Control; D012248:Rhodotorula / Q000502:physiology*; D013997:Time Factors