RESPIRATORY ACTIVITY AND BROWNING OF MINIMALLY PROCESSED SWEETPOTATOES

摘要

Sweetpotatoes (Jpomoea batatas L.), 'Brazlandia Roxa', 'Brazlandia Branca', and 'Princesa' were harvested at optimum maturity to evaluate respiratory activity and browning susceptibility of minimally processed roots. After harvest, non-blemished rootswere graded for size and diameter, and 'minimally processed' (washed, sliced, rinsed, sanitized in NaOCi and slices centrifuged for 5 minutes) inside a cold room. Some of these minimally processed roots were placed in sealed glass jars and stored at 3°C to evaluate respiratory activity during a 4-hour period or were packed in plastic films with partial vacuum to evaluate development of browning. Packages were stored under refrigerated conditions (3°C) for 5 days. Daily, minimally processed roots wereevaluated for browning according to a scale ranging from 0 (extremely browned) to 5 (no browning) using an objective assay (absor-bance at 340 nm). Minimally processed roots showed a pronounced increase in CO_2 evolution immediately after processing. 'Princesa' had the highest respiratory activity among the evaluated cultivars, being 40% higher 2 hours after processing than the other cultivars. 'Brazlandia Roxa' and 'Brazlandia Branca' were significantly less susceptible to browning compared to 'Princesa', which was rated as unacceptable for commercial use at the end of the 5-day storage period. Brazlandia Roxa' and 'Brazlandia Branca' were still marketable at the end of the storage period.