Search

Generally, commercial rice wine has stable quality with bland flavor, while traditional rice wine has a mellow taste but is unstable in quality. In order to solve this problem, the influence of mixed culture fermentation with monocultures of culturable fungi producing amylase, protease and esterase isolated from Jiuqu from different regions in China and commercial sweet wine koji on the quality of rice wine was assessed. According to the enzyme-producing characteristics and 18S rDNA gene sequence analysis, the five obtained strains were identified as Rhizopus oryzae, Mucor circinelloides, M. lanceolatus, and two strains of Saccharomycopsis fibuligera (XG and HB). The addition of S. fibuligera HB increased the contents of ethanol and amino nitrogen, enriched the types and contents of organic acids, reduced the contents and percentage of bitter amino acids, and increased the contents of volatile compounds when compared with the control group (commercial sweet wine koji alone). More importantly, the contents of phenethyl alcohol and ethyl acetate were significantly higher than those in the other groups. Therefore, S. fibuligera HB can significantly improve the quality of rice wine, suggesting its application potential in multi-strain Qu for rice wine.

Based on the self-polymerization reaction of dopamine (DA), a polydopamine (PDA) film was formed on the surface of silver nanoparticles (AgNPs) and glassy carbon electrode (GCE), which could result in uniform dispersion of AgNPs on the surface of GCE. As a result, PDA@AgNPs/GCE modified electrode was obtained. The self-polymerization time of DA and the electrochemical test method and conditions for chlorpromazine were investigated and optimized to establish a rapid method for the detection of chlorpromazine based on square wave voltammetry. The modified electrode was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Under the optimal conditions, the oxidation peak current of chlorpromazine on PDA@AgNPs/GCE had a good linear relationship with its concentration in the range of 5.0 × 10-8–1.0 × 10-5 mol/L (R2 = 0.991). The detection limit (RSN = 3) was 1.7 × 10-8 mol/L. The recoveries of chlorpromazine in spiked pork, chicken and beef samples were 84.9%–88.8%, 79.8%–93.8% and 80.6%–93.9%, respectively. The instrument used in the method was light and portable, and the preparation method of the modified electrode was simple, easy, cheap, and convenient for batch preparation of modified electrodes, and could be used for the rapid detection of chlorpromazine in livestock and poultry meat.