In vitro biological activity and nutritional evaluation of purple potato (Solanum tuberosum L. var. Vitelotte)

This study aimed to produce functional flour from purple potatoes, which are relatively less known and have limited usage. Purple potatoes (Solanum tuberosum L. var. Vitelotte) and yellow potatoes (Solanum tuberosum L.) used in this study were cultivated in Türkiye. The purple potato flour (PPF) displayed higher values across various parameters, including total phenolic compounds, total flavonoids, total anthocyanins, antioxidant capacity, phenolic content, as well as in-vitro biological activities such as bioaccessibility, anti-diabetic activities, and anti-inflammatory properties, compared to the yellow potato flour (YPF). The mineral content ranking for both flour samples was K > P > Na > Mg > Ca > Fe > Zn > Mn > Cu > Se. The predominant phenolic compounds in PPF were chlorogenic acid, D-( +) malic acid, ferulic acid, and succinic acid. The compounds from anthocyanins found in purple vegetables and fruits, including malvidin chloride, cyanidin chloride, and cyanin chloride, were identified in PPF. PPF exhibited an average in-vitro bioaccessibility of 60%, whereas YPF demonstrated a slightly lower value of 48%. Regarding their in-vitro anti-diabetic activities, PPF showcased an α-amylase inhibition rate averaging 51.67% and an α-glucosidase inhibition rate at 36.22%. As a result of the study, it was observed that purple potato flour was a rich source of total phenolic content, dietary fiber, minerals, antioxidants, and anthocyanins. Considering its gluten-free nature, this functional flour is considered a potential alternative flour source for individuals with celiac disease, opening up new possibilities for various applications in our daily nutrition.