Mashing Experiment Of Beer With Extruded Rice As Adjuncts

The substitution of extrusion for traditional cooking technology as the way of gelatinizing the adjuncts of beer has many advantages, such as a higher level of extracts, a quicker fermentation of worts, a simplified saccharification process and the economy of energy consumption. With the costs of beer decreased by application of the technology, it is considered more valuable. In this dissertation, with extruded rice being adjuncts of beer, important relevant issues about the saccharification process were researched systematically. 1, It is the pivotal point on the application of extruded rice as adjuncts of beer that the filtration of worts is slow, which is the obstacle to the application of the technology. In this dissertation the method of orthogonal test design was applied to discuss the relationship between the extrusion system parameters and the filtration time and some other important indexes of worts. With the optimization of the test results, the best extrusion system parameters were obtained based on the filtration time of worts. And the main indexes of worts under the best extrusion system parameters were better than the control?s. It?s indicated that if only the extrusion system parameters were quantified reasonably, the difficulty of filtration of worts containing extruded rice could be overcome. 2, With extruded rice and boiled rice used as substrates, the quantitative research was first conducted on the properties of malt a 梐mylase, and Michaelis constants of malt a 梐mylase were measured. The results indicated that extruded rice was more apt to be hydrolyzed by malt a 梐mylase than control, which is the foundation of the substitution of extrusion for traditional cooking technology as the way of gelatinizing the adjuncts of beer. 3, Based on the basic principle of filtration, the quantitative research was first conducted on the poor filtration behavior of worts containing extruded adjuncts. The size and shape of the filtration cake particles were proposed to be the primary factors to result in the poor filtration behavior of worts containing extruded adjuncts. 4, With the method of regression analysis, the productivity and the per kilowatt梙our yield of the extruder were studied, and based on the results, the energy consumption of saccharification process containing extruded rice and boiled rice was first calculated theoretically. It was indicated that the substitution of extrusion for traditional cooking technology as the way of gelatinizing the adjuncts of beer would decrease the energy consumption of saccharification process by 15. 33%, but the exergy efficiency decreased either. With the boiling process at lOOt cancelled, in order to increase the exergy efficiency of saccharification process with extruded rice as adjuncts, the atmospheric steam should be used as heating steam. 5, Iodine reactions of worts containing extruded rice were tested systematically. The results indicated that the resistant starch formed during extrusion resulted in the problems of iodine reactions of worts containing extruded rice. Doctoral Candidate: Meng Yang Supervisor: Prof. Shen Dechao...