STUDY OF THE DEGRADATION KINETICS OF CROCIN DURING STORAGE AT DIFFERENT TEMPERATURES: EFFECT OF pH VARIATION AND THE USE OF PRESERVATIVES

Abstract

Saffron is the most expensive spice in the world, not only due to its labor-intensive production and very low yield, but also because of its multitude of therapeutic properties. Despite the development of many functional food products, maintaining the stability of saffron compounds remains a significant challenge for both researchers and manufacturers. This study focused on investigating the stability of crocin, the bioactive compound responsible for saffron’s color, under various temperatures, using different media with varying pH levels and preservatives. Crocin was stored in media with different pH levels (2, 5, 7, and 8) and in the presence of preservatives (EDTA, citric acid, and ascorbic acid) at variable temperatures (5, 20, and 35 °C), with analyses performed at different time intervals. The results revealed that the degradation kinetics of crocin followed a second-order reaction. It was found that neither an acidic medium (pH 2) nor neutral or basic pH levels were suitable for crocin storage; only pH 5 provided satisfactory stability. The use of preservatives showed positive effects on crocin’s stability, with ascorbic acid demonstrating the best results in terms of half-life, particularly at lower storage temperatures of 5 °C and 20 °C, with half-lives of 266.34 and 141.97 days, respectively. For optimal crocin storage, it is recommended to use ascorbic acid as a preservative in a weakly acidic medium, while avoiding high temperatures.