Stability of Betanin as a Colorant in Pickled Turnips under different Light Exposure Conditions and with Different Additives

Abstract

We compared the stability of the food colorants betanin and red-beet extract in pickled turnips over a 14-week period and under different storage conditions that varied in terms of light exposure and additive content. Our findings showed that when exposed to 6 hours of sunlight or fluorescent light, on a daily basis, betanin was highly more stable than red-beet extract even when red-beet extract was stored in complete darkness. We further investigated the effect of metals and oxidation on the stability of betanin. Our results determined that EDTA and ascorbic acid significantly improved the stability of betanin colorant in pickling solution, even when exposed to direct sunlight. We tested the effect of four different concentrations of EDTA (100, 150, 200, and 250 mg/kg) and three different concentrations of ascorbic acid (200, 400, and 500 mg/kg) on the stability of betanin. EDTA (250 mg/kg) provided the highest improvement to betanin stability among all EDTA concentrations that were used in the study. Also, ascorbic acid (500 mg/kg) provided the highest improvement to betanin stability among the ascorbic acid concentrations that were used in the study.