Physicochemical, Textural, and Antioxidant Attributes of Yogurts Supplemented with Black Chokeberry: Fruit, Juice, and Pomace

The fruit, juice, and pomace of black chokeberry (Aronia melanocarpa) are a rich source of phenolic compounds and can be used to obtain enriched dairy products. Chokeberry fruit, due to its astringent taste, is less favorable or even unacceptable to consumers and is usually processed into juice, resulting in large quantities of pomace, which is often discarded as waste. The aim of this study is to valorize chokeberry fruit, juice, and pomace by incorporating them in different percentages (1, 2, and 3%) into yogurt as functional ingredients. The physicochemical (total solids content, fat, protein, titratable acidity, pH, color), textural (hardness, adhesion, cohesiveness, springiness, gumminess, and chewiness), antioxidant (DPPH scavenging activity and total phenolic content), and sensory characteristics of supplemented yogurts were investigated. The results showed that the addition of chokeberry pomace in yogurt increased their total solids content (from 11.46 ± 0.18% for the plain yogurt sample to 13.71 ± 0.18% for the yogurt sample with 3% chokeberry pomace), while the addition of fruit and juice decreased the protein content of the yogurt samples (from 4.35 ± 0.11% for the plain yogurt sample to 3.69 ± 0.15% for the yogurt sample with 3% chokeberry fruit and to 3.84 ± 0.1% for the yogurt sample with 3% chokeberry juice). There was no statistically significant change in the fat content of all samples of chokeberry-supplemented yogurt compared to plain yogurt. The pH of the yogurt samples decreased with the increase in the percentage of chokeberry fruit, juice, and pomace added to the yogurt (from 4.50 for the plain yogurt samples to 4.35, 4.30, and 4.20 for the yogurt samples supplemented with 1, 2, and 3% black chokeberry pomace). Inhibition of DPPH radical formation was higher in the yogurt samples with chokeberry fruit (57.84 ± 0.05%, 73.57 ± 0.11%, and 75.38 ± 0.05% inhibition for the samples with 1, 2, and 3% fruit) and pomace (up to 64.8 ± 0.11% inhibition for the sample with 3%), while total phenolic content decreased (from 392.14 ± 2.06 to 104.45 ± 2.63 µg/g) as follows: yogurt with chokeberry pomace > yogurt with chokeberry fruit > yogurt with chokeberry juice. The yogurt samples with the highest acceptance scores were the samples with 3% and 2% black chokeberry fruit, while the lowest acceptance score was obtained for the yogurt sample with 3% black chokeberry pomace. Chokeberry fruit, juice, and pomace can improve the physicochemical, textural, and antioxidant characteristics of yogurt, emphasizing that the antioxidant effect of yogurt could be substantially improved by the addition of chokeberry pomace due to its high phenolic content, while incorporation into yogurt is another way to valorize this by-product.