Optimization of esterase production from Monascus purpureus Y146 by artificial neural network-genetic algorithm and its application in flavor enhancement of fermented wine.
Optimized esterase production from Monascus purpureus Y146 significantly enhances volatile compound diversity in rice wine fermentation.
Where it sits
this study against the rest of the vasopressin corpusSummary and findings
The study optimized esterase production from Monascus purpureus Y146 using various methodologies, achieving an activity of 1248.02 U/mL. This represented a 4.68-fold increase over unoptimized conditions. The esterase was applied in rice wine fermentation, enhancing the diversity and abundance of volatile compounds.
Abstract
Esterases play an important role in flavor regulation during food fermentation. In this study, a high esterase-producing strain, Monascus purpureus Y146, was used to optimize esterase production via one-factor-at-a-time experiments (OFAT), response surface methodology (RSM), and an artificial neural network with genetic algorithm (ANN-GA) approach. The esterase was partially purified and characterized, and its application in rice wine fermentation was evaluated using HS-SPME-GC-MS. The results showed that the esterase activity of the Y146 strain reached up to 1248.02 U/mL, a 4.68-fold increase over the unoptimized condition, under conditions of 16% seed inoculation, 10 g/L L-arginine addition at 84 h, pH 7, and 8.69 d of fermentation. The partially purified esterase preparation exhibited optimal activity at 30 °C and pH 7, showed enhanced activity in the presence of 2 mM Fe2+, and had an approximate half-life of 9 h. HS-SPME-GC-MS analysis identified ethyl caprate as the only aroma-active compound (OAV > 1) detected in the control group. Following addition of the partially purified esterase preparation, increased diversity and abundance of volatile compounds were observed, with the number of aroma-active compounds increasing from one to six, including ethyl undecanoate, ethyl hexanoate, ethyl palmitate, ethyl linoleate, 1-dodecanol, and 2,4-Di-tert-butylphenol. These findings highlight the potential application of the M. purpureus Y146-derived partially purified esterase preparation in flavor-oriented fermented food systems.
Background
The study addresses the optimization of esterase production for flavor enhancement in fermented foods. Esterases are crucial in regulating flavors during fermentation, which is significant for food industries aiming to improve product quality. Prior to this study, the potential of Monascus purpureus Y146 in esterase production and its application in flavor enhancement was not fully explored.
Methods
The study used Monascus purpureus Y146 to optimize esterase production through one-factor-at-a-time experiments, response surface methodology, and an artificial neural network with a genetic algorithm. The fermentation conditions included 16% seed inoculation, 10 g/L L-arginine addition at 84 hours, pH 7, and 8.69 days of fermentation. The esterase was partially purified and characterized for its application in rice wine fermentation.
Results
The primary endpoint showed an esterase activity of 1248.02 U/mL, representing a 4.68-fold increase over unoptimized conditions. The optimal activity was observed at 30 °C and pH 7, with a half-life of approximately 9 hours. The application in rice wine fermentation led to an increase in the diversity and abundance of volatile compounds, with aroma-active compounds increasing from one to six.
Interpretation
The study demonstrates a significant increase in esterase production using advanced optimization techniques, which could enhance flavor profiles in fermented foods. While the increase in volatile compounds suggests potential applications, the clinical significance in terms of consumer preference or market impact remains untested. The study's findings are limited by the specific conditions and strain used, which may not generalize to other systems.
Key findings
- Esterase activity reached 1248.02 U/mL.
- 4.68-fold increase over unoptimized conditions.
- Optimal activity at 30 °C and pH 7.
- Half-life of approximately 9 hours.
- Increased aroma-active compounds from one to six.
Limitations
- Single strain study.
- Specific fermentation conditions.
- No consumer preference testing.
- Limited generalizability to other systems.