Enhancing set‐type yoghurt quality and bioactive compound bioaccessibility with a phenolic‐ and anthocyanin‐rich extract powder derived from red–purple fruits and vegetables

Background Yoghurt fortification with phenolic‐ and anthocyanin‐rich plant extracts has been widely studied, yet their bioaccessibility during gastrointestinal digestion remains underexplored. Evaluating these interactions is important for advancing functional yoghurt formulations and guiding industrial applications. Aim This study aimed to investigate the bioaccessibility of phenolic compounds and anthocyanins during in vitro digestion of set‐type yoghurts fortified with a standardised anthocyanin‐rich powder at four levels. Additionally, the study evaluated the effects of fortification on the physicochemical, textural and sensory properties of the yoghurts. Methods Set‐type yoghurts were fortified with 0.25%, 0.50%, 1.0% and 2.0% anthocyanin‐rich extract powder obtained from black carrot, blackberry, pomegranate and sour cherry. Physicochemical composition, pH, titratable acidity, texture parameters and water‐holding capacity were determined during storage. Sensory analysis assessed consumer acceptability. In vitro digestion was conducted to evaluate phenolic and anthocyanin retention through gastric and intestinal phases. Data were statistically analysed to determine significant differences at the level of P < 0.05. Major Findings Phenolic retention was higher in the gastric phase but decreased in the intestinal phase (2–20%, P < 0.05), with greater losses at higher fortification levels. Anthocyanin recovery increased at fortification levels between 0.25% and 1.0% with the phenolic‐ and anthocyanin‐rich extract powder; however, an increase to 2.0% was associated with reduced recovery during digestion. Fortification with this extract powder significantly increased dry matter (11.72%–13.42%) and ash (0.77%–0.85%) ( P < 0.05). Yoghurts fortified at 1.0% or higher maintained more stable pH and titratable acidity during storage. Sensory evaluation indicated good acceptance, particularly at 0.25% and 0.50%. Scientific and Industrial Implications Fortification with phenolic and anthocyanin‐rich extract powder enhances the nutritional quality of set‐type yoghurt without compromising consumer acceptability. A concentration of 0.50% appears optimal for balancing stability, functionality and sensory quality, supporting its potential use in the development of functional dairy products.