TEXTURAL PROPERTIES AND SENSORY QUALITY OF PROCESSED SWEET-POTATOES AS AFFECTED BY LOW-TEMPERATURE BLANCHING

Sweetpotatoes (SP) stored for 9-12 mo after harvest were cut into cyli ndrical pieces and, following factorial experiments and response surfa ce design, were blanched at 50-80 degrees C for 15-274 min. Instrument al textural properties were measured by uniaxial compression and textu re profile analysis. Samples of selected blanching treatments were can ned in syrup for textural and sensory evaluations. Both blanching temp erature and time had significant effects on firmness. Optimal temperat ure for maximal firmness retention was about 62 degrees C. For canned SP, the 62 degrees C blanched samples were more intact (2-3-fold) and firmer (2-7-fold) than controls. Sensory texture and overall acceptabi lity were greatest for samples blanched at 62 degrees C for 30 or 45 m in before canning.