PrA activity was assayed by a fluorescent method (Kondo et al.,1999). One unit of PrA will hydrolyze 1 mg of insulin chain B (oxidized)per minute at pH 6.0 (25 C). Biogenic amines and amino acids were determined by a liquid chromatographic method as described by Lu et al. (2007) and Gómez-Alonso, Hermosín-Gutiérrez, and García-Romero (2007) with some modified. Briefly,1 mL rice wine sample and 200 lL NaHCO3 saturated solution,20 lL NaOH solution (2 M), 2 mL dansyl chloride (10 mg/mL) were mixed, and the mixture was incubated in a water bath at 70 C for 10 min, then 1 mL ammonia water (50 mg ammonia dissolved in water) was added to terminate the reaction. After centrifugation at 3000 rpm for 10 min, the supernatant were filtered by 45 lm filter,then the sample was analyzed by HPLC (Agilent 1100 series equipped with diode array detector, Waters-Atlantisd C18(46 250 mm, 5 lm)). The C18 column was equilibrated at 30 C with a mobile phase consisting of 55% methanol and 45% water.For amino acids determined, 1 mL rice wine sample, 1.75 mL of borate buffer 1 M (pH 9), 750 lL of methanol, 1 mL of target sample without any pretreatment, 20 lL of internal standard (L-2-aminoadipic acid, 1 g/L), and 30 lL of DEEMM were mixed in a screwcap test tube over 30 min in an ultrasound bath. The mixture was then heated at 70 C for 2 h. The Agilent 1100 series equipped with array photodiode detector, Waters-Atlantisd C18 (46 250 mm,5 lm) was used. The analyses were performed in triplicate. A gradient elution system with a mixture of A (25 mM acetate buffer pH = 5.8 with 0.02% sodium azide) and B (80:20 mixture of acetonitrile
and methanol) was used.