Pantnagar Journal of Research

Abstract

Vacuum foam-mat drying is a process by which a liquid concentrate along with a suitable foaming agent is used to whip to form stable foam and is subjected to dehydration in the form of a thin mat of foam at relatively low temperature. Response surface methodology (RSM) has been used to find out the effect of variable on the responses. The initial value of moisture content of raw papaya pulp was 856.023 % (db.). The total soluble solid (TSS) was tested by hand refractrometer i.e., 12.8oBrix. Parameters such as whipping time (10 minute), papaya pulp thickness (4 mm) and vacuum oven pressure (25 inch Hg), pH value 5.56 and TSS(10o Brix) remain constant throughout the work. In view of the above, present study was undertaken with objectives of studying the effect of maltodextrin (0.15-0.75kg/kg papaya pulp solid ), tricalcium phosphate (0.5-2.5%), glycerol monostearate (0.5-2.5%) and drying temperature (55-75 oC) on vacuum foam mat drying characteristics of papaya pulp and to ascertain various quality characteristics of dried papaya powder. The flowability time of papaya powder ranges from 15.65 to 23.62s. Its value is minimum at experiment run number 28 and maximum at experiment run number 1 with the combination of process conditions of temperature 65 degree C, maltodextrin 0.45 (w/w), glycerol monostearate 1.5% and tricalcium phosphate 1.5% and temperature 60 degree C, maltodextrin 0.30 (w/w), glycerol monostearate 1.0% and tricalcium phosphate 2.0% respectively. Hygroscopicity starts from 2.24 (experiment no. 30) to 6.84 (experiment no. 28) while the degree of caking is in between 1.83 (experiment no. 30) to 5.45% (experiment no. 28). On the basis of different experimental results it was found the minimum drying time was obtained (660 min.) at temperature (60 degree C), maltodextrin (0.60 gm/110gm), GMS(1.0%) and TCP(2.0 %). It was also found that flowability time has significantly affected by temperature (P<0.01), maltodextrin (p<0.05) and glycerol monostearate (P<0.1), at linear level. The effect of temperature and tricalcium phosphate on hygroscopicity was highly significant (P<0.01) while maltodextrin was significant at 10% level of significance.