Research On Malt Quality And Wort Filtration Performance

Wort filtration performance is a key index for wort filtration speed evaluation, malt quality is an important factor affecting wort filtration performance, the yield and speed are the basic requirement of wort filtration operation. The indicators of malt quality influencing wort filtration performance were studied, and wort particles grain size analysis was studied from the microscopic angle. Firstly, this research uses the small analog filtering equipment to evaluate a series of wort filtration performance parameters and main influencing factors at constant temperature and constant pressure, when the malt of different quality has been crushed, saccharification, filtration. Wort filtration performance evaluation parameters include 200 m L filtration time, total quantity of filter, filter cake weight, 20 s filtering performance and total filtration performance, the malt solubility and viscosity are the main indexes of influencing wort filtration performance. Beckman Coulter LS 13 320 Laser Diffraction Particle Size Analyzer has been used for determining the particle size distribution of wort before filtration and the filtered wort, Beckman Coulter Multisizer 3 Count and Particle Analyzer has used for granularity analysis of wort before and after filtering. The particle size distribution and particle size of wort before and after filtering can be confirmed and statistical. Within the scope of 1.37 to 2.00 μm, the particle number percentage and volume percentage have been respectively used for the establishment of the mathematical model on wort filtration performance, the results show that the correlation between particle number percentage for wort before filtration and wort filtration performance is largest.Through granularity analysis, the particle size of wort before filtration is 1.37 ~ 2.00 μm, the particle size of filtered wort is 0.69 ~ 1.00 μm, within the scope of these kinds of particle size, particle number percentage is above 80.00 %, small size particles occupies the main part in the process of filtering. Through the correlation analysis of malt quality factors and wort filtration performance evaluation indexes, the results show that the viscosity is 1.27 ~ 1.53 m Pa?s, malt solubility is 90.40 ~ 99.00 %, wort filtration performance is superior; When the viscosity is 1.53 ~ 1.59 m Pa?s, malt solubility is 85.00 ~ 90.40 %, wort filtration performance is medium; When the viscosity is 1.59 ~ 1.86 m Pa?s, malt solubility is 80.00 ~ 85.00 %, wort filtration performance is poor. Megazyme kit was developed for the determination of the different regions of β- glucan content in barley, β- glucan content arrangement is as follows: Tibetan > Xinjiang > Inner Mongolia > Gansu Wuwei > Heilongjiang > Yunnan > China Oil and Food Corporation.According to malting single factor experiment and response surface analysis, the relationship between malt solubility and four factors is as follows, germination temperature and drying temperature are the significant main factors, the grade degree of four factors influencing on malt solubility is: B(germination temperature) > D(drying temperature) > C(wilting temperature) > A(steeping degree). Malt solubility prediction model is as follows, malt solubility / % = 86.05- 0.73 A + 4.47 B- 1.02 C + 1.53 D- 4.79 A2- 7.51 B2- 7.42 C2- 8.46 D2- 4.19 AB- 2.57 AC- 5.68 AD- 2.59 BC- 1.16 BD + 0.98 CD,R2 = 0.9872. The best malting technological parameters are as follows, steeping degree is 46 %, germination temperature is 16 ℃, wilting temperature is 48 ℃, drying temperature is 78 ℃, the calculate value of malt solubility is 86.75 %, through three repeat experiment, the practical measured value is 87.00 %, malt solubility is increased from 81 % to 87 % and it was increased by 7.41%. According to the malting optimization process and the wort filtration effect, wort filtration performance is significantly increased, the total filtration performance is an average increase of 9.67(g0.8 / min0.2), it is increased by 7.83 % on average than the original wort filtration performance.