Evaluating the cooking process for obtaining hard candy from araza (Eugenia stipitata) pulp

This work was aimed at preparing hard candy from arazá (a fruit tree from the Amazon rainforest) using a sugar solution consisting of glucose syrup and invert sugar; this was cooked with fruit pulp to concentrate it. Temperature, time, soluble solids and viscosity were measured when cooking the mixture. Heat transfer was studied in an agitated steam jacketed kettle using the experimental data. The best arazá hard candy formulation consisted of 15% fruit pulp, 2% pectin regarding the amount of pulp and 85% sugar solution (glucose syrup and invert sugar mixed 1:1 (w/w)). The experimental data gave 266 W/m2ºC average overall heat transfer coefficient whereas theoretical data gave a 421.8 W/m2ºC overall heat transfer coefficient. Heat transfer speed was 3,140 W.