浓香型白酒窖池窖龄及空间位置对窖泥理化性质和酶活性的影响OA

The effects of different pit ages and spatial position on the physicochemical property and enzyme activity of pit mud in strong-flavor(Nongxiangxing)Baijiu were investigated,and their correlations were analyzed.The results indicated that characteristics of pit mud were significantly altered by pit age.With the increase of pit age,bulk density and fractal dimension were continuously decreased,while porosity,pore tightness,pore connectivity,and anisotropy values were increased.The soil moisture content,ash content,total carbon,total nitrogen,and δ13C carbon isotope ratio reached their maximum value in century-old pit mud.pH was observed to exhibit an initial increase followed by stabilization with pit age increased,while humic acid content was found to decrease over time.The C/N ratio was the highest in new pit mud.The lowest activities of phosphatase,β-glu-cosidase,and cellobiohydrolase and peroxidase were detected in century-old pit mud,indicating a stable maturation state of pit mud.The physicochemi-cal properties and enzyme activities of 3-years-old pit mud were found to fluctuate significantly across different spatial locations,whereas enzyme ac-tivities in 40-years-old and century-old pit mud were shown to exhibit minimal variation across locations.This indicated that newly formed pit mud was characterized by low maturity during the initial acclimatization phase,resulting in an unstable environment for microbial growth.The correla-tion results indicated that there was a synergistic effect among the physicochemical factors of pit mud,which jointly influence its function.Phos-phatase and β-N-acetylglucosaminidase had significant correlations with some physicochemical properties of pit mud,and C/N and pH were the main factors affecting the enzyme activity of pit mud.This study revealed the time-space coupling mechanism of pit mud functional evolution,providing a theoretical basis for ecological regulation and flavor metabolism optimization of traditional Baijiu fermentation pits.