Abstract:

Single factor experiments were carried out to confirm the optimal concentrations of six browning inhibitors
added to litchi wine. Based on the results, orthogonal array experiments involving six factors at two levels were designed
to determine the effectiveness of inhibitors in terms of inhibition rate using an L8 (27) orthogonal array design. The four
inhibitors with the greatest effects on browning inhibition were L-cysteine, glutathione (GSH), ethylene diamine tetraacetic
acid disodium (EDTA-Na2) and citric acid. The experimental data were analyzed by response surface regression using
Design-Expert 8.0. The results showed that the best browning inhibitor for litchi wine was obtained by the combined use
of 8.46 mmol/L L-cysteine, 1.16 mmol/L GSH, 1.87 mmol/L EDTA-Na2, and 1.89 mmol/L citric acid. The predicted value
of browning inhibition rate using the optimized combination of browning inhibitors was 47.89%, and the actual value was
50.18%, representing a coincidence rate of 95.44%.

Key words: litchi wine, browning inhibitor, browning inhibition rate, orthogonal experimental design, response surface methodology