Respiratory activity and browning of minimally processed sweet potatoes

摘要

Sweet potatoes (Ipomoea 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 roots were graded for size (18±2cm) and diameter (5±1cm), and minimally processed inside a cold room. Processed roots were placed in sealed glass jars and stored at 3±0.5°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±0.5°C) for 5 days. Daily, minimally processed roots were evaluated for browning according to a scale ranging from 0 (extremely browned) to 5 (no browning) and using an objective assay (absorbance at 340 nm). Minimally processed roots showed a pronounced increase in carbon dioxide evolution immediately after processing. 'Princesa' had the highest respiratory activity among the evaluated cultivars, being 40% higher two 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 storage period. 'Brazlandia Roxa' and 'Brazlandia Branca' were still marketable at the end of the storage period.