Physicochemical study of pinhao flour as source of adjunct in beer production

摘要

Pinhao seed flour can be used as a soluble adjunct in the production of beer. The objective of this work was to determine the proportion of pinhao flour and barley malt to obtain a suitable extract for beer production. In addition, as a source of starch it is important to determine the viscoamylographic properties and chemical composition. To achieve this, three samples of pinhao flour were manufactured: raw, frozen raw and pre-gelatinised flour. Of these, pre-gelatinised pinhao flour was compatible with the brewing process, with low gelatinisation point and low viscosity. Raw and frozen raw flour showed a high gelatinisation point ( 78 degrees C) which required the same pre-treatment as processed corn and rice. The total starch yield for pinhao flour was 63.8% on a dry basis. The most effective blend was 20% of pinhao pre-gelatinised flour and 80% malted barley. This increased the yield by 10%, thereby proving economically attractive. The pinhao flour adjunct contributed no functional enzymes to the mashing process, made no contribution to beer colour and made a positive contribution to the body and head retention. This influenced the filterability and the colloidal stability of the beer. The use of pinhao flour as a brewing adjunct does not require chemical agents or pre-treatment. The pre-gelatinisation and drying procedures provide a simple and cheap method for obtaining pinhao flour for both pilotscale and commercial production. (C) 2018 The Institute of Brewing & Distilling