Analytical optimization of a phenolic-rich herbal extract and supplementation in fermented milk containing sweet potato pulp

- An herbal extract containing clove, lemongrass and green mate was optimized.
- The optimized extract (OE) was rich in chlorogenic acid, isoquercitrin, rutin, and gallic acid.
- OE increased the antioxidant activity and total phenolics of fermented milks.
- Fermented milks had a good sensory acceptance.

The aims of the present study were to optimize and characterize the phenolic composition of a herbal extract composed of green mate (Ilex paraguariensis), clove (Syzygium aromaticum), and lemongrass (Cymbopogon citratus) and to propose the addition of this polyphenol-rich extract to fermented milks (FM) with/without sweet potato pulp (Ipomoea batatas). Proximate composition, pH, acidity, instrumental texture profile, total phenolic content (TPC), antioxidant activity (AA) of all formulations were measured, and sensory attributes were also investigated. The addition of a lyophilized extract (1 g 100 g−1) containing 87.5% clove and 12.5% green mate increased the AA and TPC, while FM with added sweet potato pulp had the best sensory acceptance. The TPC and total reducing capacity had a slight change during 21 days of storage. The data showed that herbal extracts and sweet potato pulp may be used to develop new dairy foods with potential functional properties.

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