Boost anti-oxidant activity of yogurt with extract and hydrolysate of cinnamon residues

Objective: This study was conducted to explore the potential use of cinnamon residues (twigs and leaves) in boosting the anti-oxidant activity of yogurt. Methods: The cinnamon bark was used as the benchmark. The extracts of cinnamon bark (BW), twigs residue (TW), and leaves residue (LW) were prepared by using water, whereas the hydrolysates of cinnamon bark (BE), twigs residue (TE) and leaves residue (LE) were prepared via cellulase hydrolysis. The extracts and hydrolysates were then co-fermented respectively with the skimmed milk to produce yogurt. Results: Results obtained indicated that BW and TE yogurt possessed the highest anti-oxidant activity. In vitro digestion improved the anti-oxidant activity of yogurt significantly (P < 0.05). DPPH activity of the LW yogurt was improved drastically after in vitro digestion. Although the total phenolic content (TPC) and total flavonoids content (TFC) of LW were lower than BW, the anti-oxidant activity of LW yogurt was not significantly different (P < 0.05) with the BW yogurt after digestion. Conclusion: This study suggested that the anti-oxidant activity of the cinnamon yogurt was influenced by complex protein-phenolic interactions. (C) 2019 Tianjin Press of Chinese Herbal Medicines. Published by Elsevier B.V. All rights reserved.