Polyphenols, carotenoids and flavonoids in an antioxidant probiotic yogurt made with tumbo pulp (Passiflora tripartita Kunth)

The species Passiflora tripartita Kunth (tumbo) is endemic to South America, whose edible fruits are a rich source of antioxidant metabolites. This study aimed to develop a probiotic yogurt with tumbo fruit pulp, consisting of an adequate antioxidant capacity related to its content in phenolic compounds, flavonoids, and carotenoids, and with good acceptability. Antioxidant capacity was determined by radical scavenging capacity test (DPPH•) and cation radical scavenging capacity test (ABTS+•), total phenol content by Folin Ciocalteu method, total flavonoids, and carotenoids by spectrophotometric method, on days 1, 7, 14 and 21 of storage. The surface plate count method quantified Lactic Acid Bacteria (LAB). The results evidenced that at day 21 of the analysis, the antioxidant capacity presented high values (DPPH•: 8.774 mg GAE/g, 3.386 mg TAE/g, 6.159 mg AAE/g; ABTS+•: 11.630 mg GAE/g, 7.018 mg TAE/g, 9.218 mg AAE/g), the content of phenolic compounds presented high values (3746.389 mg TPGAE/g; 2355.933 mg TPTAE/g), as well as total flavonoids (52.421 mg Quercetin/g) and carotenoids (72.109 μg β-carotene/g). Yogurt presents a value of 3.4 x 10⁸CFU/g of LAB and it is therefore considered a probiotic. High values were determined as the sensory characteristics such as odor (6.89), color (6.97), texture (6.94), flavor (6.97), and acceptability (6.94), thus being analyzed according to the hedonic scale in 200 panelists. The physicochemical and microbiological quality of the yogurt complies with current regulations. In conclusion, the probiotic yogurt developed with tumbo fruit pulp had a high amount of LAB. It presented high antioxidant capacity correlated with its high content of phenolic compounds, flavonoids and carotenoids, which remained high during the 21 days of storage. Furthermore, it showed high acceptability and had adequate physicochemical and microbiological quality.