Abstract

Hong Quan fruit has a high content of bioactive compounds known as antioxidants, antimicrobial, and anticarcinogenic substances. The study aimed to optimize the temperature and pasteurization time of ready-to-drink beverages to yield a functional product. The response surface methodology with central composite design (22 + stars) was exploited to optimize the pasteurization process for residual bioactive compounds (phenolic, flavonoid, tannin, and Vitamin C) as well as the antioxidant activity of Hong Quan beverage. The bioactive compound content was determined using a spectrophotometer; 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays were used to evaluate the antioxidant ability of the product. The results showed that optimal processing at the temperature of 90.32oC for 25.05 min. Under this condition, the predicted values of the phenolic, flavonoid, tannin, and Vitamin C contents were 28.90 mg GAE/100 g, 7.08 mg QE/100 g, 102.08 mgTAE/100 g, and 15.73 mg/100 g, respectively; and DPPH assay was 85.77% and FRAP assay was 8.05 μM FeSO4/g. These predicted data were close to real tested data and the different percentage was around 0.8% to 4.7%.

Key words: Flacourtia jangomas fruits, antioxidant ability, bioactive compounds, beverage, pasteurization process, response surface methodology.