Investigation of storage response of a plant latex based soft candy colored with blue pigment obtained from Arthrospira (Spirulina) platensis

Abstract In this study, sugared and sugar-free toffee type soft candy samples were produced by means of using a plant-based latex obtained from Gundelia tournefortii L. (known as kenger gum) with a new process. As a natural blue color source, different amounts of phycocyanin (0.1, 0.3, and 0.5 g/100 g) were added to candy samples, and various quality parameters were examined by comparing with the conventional toffee sample. According to the results, water activity of all samples belonging to control, kenger gum-added sugared (KS) and sugar-free (KSF) groups were found as 0.5745–0.5957, 0.6297–0.6388, 0.5471–0.5570, respectively. There were significant differences between the L*, a*, and b* values of phycocyanin-free control, KS, and KSF samples. However, phycocyanin was more stable especially in KS group (ΔE, 1.46–2.71) during the storage compared to other two groups. Textural parameters of the samples changed depending on difference in the compositions i.e., kenger gum and sugar alcohols, regardless of phycocyanin concentration. High consumption appeal was achieved by the integration of kenger gum and phycocyanin in toffee type soft candy production. According to the outputs, kenger gum can be effectively employed as a base ingredient in such products and phycocyanin can serve as a natural blue color in the production. Graphical Abstract