Optimization of Chinese Chive Juice as a Functional Feed Additive

Allium tuberosum, commonly known as the Chinese chive (CC) is often used as a traditional medicine in East Asia for its health benefits. To explore the potential of CC as a functional feed additive, antibacterial and antioxidant assays, untargeted metabolomics, and a 2 × 3 × 3 fractional factorial design (FFD) were conducted. In the present study, CC displayed stable DPPH radical scavenging activity with constant total phenolic content, however, the total flavonoid contents and the antibacterial activities were attenuated following heat treatment. The FFD results identified the solid content (SBM) as the main determinant of the antibacterial activity and moisture content of the CC products along with two other factors: drying time and temperature. Two CC products manufactured with 30% (w/v) SBM with 3 h drying at 80 °C and 20% (w/v) SBM with 8 h drying at 60 °C obtained the maximum antibacterial activity and least moisture content (