Research Into The Brewing Process Using Wheat Flour As Adjunct

Compared with other adjuncts, wheat flour contains high concentration of compounds ofpentosan-protein, beneficial to beer foam retention, and also contains low content ofpolyphenol, and the latter will benefit non-biological stability of beer. However; wheat flourcontains high content of ferulic acid, which can be the precursor of flavor votatile compounds4-vinyl guaiacol(in short,4-VG), and can be transfermed into4-VG by ale yeast. At thepresent time, wheat is the main food crop, widespreadly grown in China, thus Chinesebreweries will obtain sufficient supply on condition that wheat flour is a good substitute ofbrewing adjunct, and it will also contribute to reduce the cost of beer production. Thefollowing research points have been carried out:Firstly, some experiments have been done to test some important paremetrs according tothe demands of brewing adjuncts. In comparison to two method of detection limit, precision,repeatability, determination of fatty acid and Ellman’s of new and old wheat flour showed thatfatty acid value of wheat flour would be more beneficial and advantageour to evaluate thestale strengthed of wheat flour. The intemal fatty acid value less than8.5mgKOH/100g hasbeen set up.By optimizing orthogonal design test, to establish saccharification process by usingwheat flour as beer adjunct (adding amount of20%of wheat flour) is as follows, the addingdosage of α-amylase,neutral protease in cooker are following, respectively,20u/g,0.15ml/kg.And an100L pilot scale experiment has been tested to determine the feasibility of the process.The results showed that the process metioned above was of great practice.The most typical characters are following in terms of beer quality and sensory evulationby using wheat flour as a adjunct.Higher levels of flour xylan and compounds of pentosan-protein, results in higherviscosity of wort and beer, which leads to more yeast suspension. After fermentation, wheatflour also contributes to beer foam retention because of higher concentration of hydrophobicprotein.4-vinylguaiacol is typical aroma flavor substance for wheat beer, and the methodology todetect4-vinylguaiacol by HPLC based on the fluorescence characteristics of the substance,have been set up. The relative standard deviation of the detection method, and the recoveryare following, respectively,0.7236%, and from91.97%, the detection limit is0.005mg/L.Beer sample brewed with20%wheat flour has more than4mg/L of4-vinyguaiacol, and wasof great character of wheat beer.