Effect of sloe berry ( <i>Prunus spinosa</i> L.) powder addition on physicochemical, rheological, antioxidant, and sensory properties of stirred yoghurt: a multivariate approach

In this study, stirred yogurt was produced using sloe berry powder at different ratios (0, 2, 4, 6, and 8%) and stored for 21 days. The effect of sloe berry powder addition on physicochemical properties was limited, whereas the effect of storage period was more pronounced. Lactic cocci and lactic bacilli counts ranged between 7.78–8.93 log CFU/g and 6.19–9.13 log CFU/g, respectively. Yeast and mold were detected in all samples after 14 days of storage. All color parameters were significantly affected by sloe berry powder addition (p < .001), whereas storage period had no significant effect (p > .05). Total phenolic content and antioxidant capacity increased with increasing levels of sloe berry powder. Only the potassium (K) content was affected by the addition of sloe berry powder. Viscosity and consistency values increased in yogurts containing 6% and 8% sloe berry powder on days 14 and 21 of storage. Sensory scores decreased in all samples at the end of storage. Principal component and correlation analyses indicated that the addition of sloe berry powder and storage period exerted distinct effects on the evaluated parameters. Overall, sloe berry powder can be considered a promising ingredient for the development of nutritional and functional stirred yogurt.