Stability of bioactive compounds and in vitro gastrointestinal digestion of red beetroot jam: Effect of processing and storage

The stability of total phenolics, flavonoids and betalains , as well as antioxidant capacity of red beetroot during jam processing, storage and in vitro gastrointestinal digestion were measured using spectrophotometry . Results suggested that jam processing led to a significant reduction of total phenolics (13.8%), betalains (56.3%) and antioxidant capacity (13.2–28.2%), but a significant increase of total flavonoids (99.3%). After storage at 4 °C for 90 days, the losses of total phenolics, flavonoids, betalains and antioxidant capacity were 33.9, 10.6, 7.9 and 9.7–35.7%, respectively. In addition, jam processing improved the bioaccessibility of total phenolics, flavonoids, betalains and antioxidant capacity using in vitro simulated gastrointestinal digestion analysis. The results of this study suggested that the main bioactive compounds of red beetroot including phenolics, flavonoids and betalains, could be partially preserved during jam processing and storage, with higher levels of bioaccessibility. Therefore, the red beetroot was a promising material for the development of functional foods.