Combination of sonication with anti‐browning treatments as a strategy to increase the shelf life of fresh‐cut potatoe (cv. Monalisa)

Abstract

Two antioxidant solutions, a patented mixture based on vitamin C and other compounds (Natureseal®, MV) and green tea extract (GT), were proposed to prevent browning in sliced potatoes. Combination with ultrasound (US) at two frequencies (35 and 130 kHz) was also evaluated, but no significant enhancement of the effects was detected with US. In MV-treated samples, respiration rate and dry matter (19.7%) were higher than they were in the control (CK) (17.3%) or GT-treated samples (16.8%). Neither membrane integrity nor malondialdehyde content was significantly affected by the addition of MV or GT, but in MV samples the antioxidant activity was increased sixfold at the beginning of the storage (39.1 mmol ascorbic acid equivalents/kg), but decreased after 9 days. A yellowish coloration on the surface of GT samples (L*a*b* values being 68.3, −6.4, and 25.3, respectively), attributed to the coloration of the tea concentrate, was observed. In the conditions studied, GT was not able to delay browning in potatoe slices. In contrast, MV solution preserved the original color of the sliced potatoes (69.6, −6.7, and 27.7 for L*a*b*, respectively), during the 9-day storage at 4°C. Novelty Impact Statement Sulfites are used as an additive to maintain food color, shelf life, and prevent the growth of fungi or bacteria. However, they are considered as allergenic substances. The study proves the efficacy of vitamin C as a substitute to sulfites to preserve fresh-cut potatoes and delay their browning.