Vitamin C retention in fresh-cut potatoes

Abstract

The effect of cutting and storage in air (AIR), modified atmosphere packaging (MAP) and deep-freezing (DF) on the vitamin C content of potato strips was evaluated. The -ascorbic acid (AA) content of potato strips derived from five potato cultivars (‘Agria’, ‘Cara’, ‘Liseta’, ‘Monalisa’ and ‘Spunta’) previously held in long-term storage was determined. In a second experiment, new-season potato tubers of ‘Agria’ and ‘Spunta’ cvs were used. Fresh-cut potato strips were stored for 6 days at 4 °C while DF strips were evaluated up to 5 weeks upon storage at −22 °C. All fresh-cut samples stored in AIR showed an increase in AA content (16–108%) after 2–4 days at 4 °C. At the end of storage, all fresh-cut potatoes stored in AIR had AA contents at or above initial concentrations, except new-season ‘Spunta’ tubers which experienced a 26% decrease. Moreover, potato strips from new-season ‘Agria’ tubers increased in vitamin C content after 6 days by 12%. Steady state MAP conditions were reached after 2 days with concentrations of 8.2–9.8 kPa CO2 and 3.1–3.8 kPa O2 within the packages. Potato strips stored in MAP decreased in AA content by 14–34% compared to samples held in AIR. Frozen storage resulted in a reduced vitamin C content (23%) of ‘Spunta’ potato strips after 5 weeks while ‘Agria’ tubers did not show any change. A general increase over time in the respiration rate of potato strips was observed during storage at 4 °C. As a conclusion, vitamin C content of fresh-cut potatoes was retained in AIR storage after 6 days at 4 °C while it was reduced in MAP storage and frozen storage at −22 °C.