A technical strategy to prolong anthocyanins thermal stability in formulated purple potato (Solanum tuberosum L. cv Bora valley) processed by hot‐melt extrusion

Summary The thermal instability of anthocyanins is a crucial challenge in processed food industries. To overcome this fact, biopolymer‐mediated purple potato (PP) formulations (BEFP) were developed by hot‐melt extrusion (HME). The BEFP were composed of PP+ whey protein concentrate (WPC) (F2), PP+ WPC+ ascorbic acid (AA) (F3), PP+ soy lecithin (LCT) (F4), and PP+ LCT+ AA (F5). The freeze‐dried and extrudate PP was treated as standard (F0) and control (F1), respectively. The physical and chemical properties of the extrudate BEFP was evaluated by Fourier‐transform infrared spectroscopy (FT‐IR) and Scanning electron microscopy (SEM). It was observed that anthocyanins remained higher in aqueous media in F5 formulation. Chromatographic analysis showed many folds higher total anthocyanins (23 folds), cyanidin (7 folds) and malvidin (2 folds) in F5 compared to F1. Moreover, peonidin and delphinidin were found absent in all formulations except F4 and F5. Likewise, total phenolic (TP) content, total flavonoids (TF) and antioxidant capacity were significantly remained higher at 2, 4 and 2 times in F5 compared to F1, respectively. It is suggested that the F5 was found to be the compatible formulation to prolong the thermal stability of anthocyanins in extrudate PP. Schematic illustration of the development of biopolymer mediated extrudate of purple potato by hot‐melt extrusion.