Comparison between barley malt protein quantification methods

Isabella De Oliveira Cenci,Grace Ferreira Ghesti,Renato Fernando Amabile,Bernardo Pontes Guimarães

doi:10.1590/fst.13920

Abstract

Brazil imports about 60% of all the malt used by the brewing industry which is spread throughout the country. Even though it is an agricultural country, only a small portion of the barley production has the characteristics to produce barley malt for brewing. Seeking supply to the ever-growing demand and reducing the dependency on other countries and logistic costs, malting industries and genetic enhancement companies endeavor to adapt barley to the Brazilian Savannah conditions. For the barley to be malted, it is crucial to develop cultivars with the necessary malting qualities and adapted to the region and with good yield. Considering the importance of protein to the brewing process, four protein quantification methods were compared: combustion methods - carbon, hydrogen and nitrogen elemental analysis and Dumas - and digestion ones - Kjeldahl and flux injection analysis (FIA). The methodologies tested showed good correlations (higher than 0.881) and variations were associated with matrix complexity. All protein quantification methods were satisfactory from an agronomic perspective. Yet, we recommend the combustion ones as they generate fewer residues and results are ready in up to 6 minutes. Therefore, they are the most suited for barley and malt analysis considering lab routine.

Highlights

IntroductionBrazil consumes up to 60.7 liters of beer per capita
On average, Brazil consumes up to 60.7 liters of beer per capita
Brazilian law states that barley to be considered appropriate for brewing use must have up to 12% protein content (Brasil, 1996)

Summary

Introduction

Brazil consumes up to 60.7 liters of beer per capita. Since 2007, Brazil is the third largest beer producer and consumer of the world (Dias & Falconi, 2018). Barley malt is the most used input and Brazilian normative states that up to 45% of primitive extract may be substituted by adjuncts. For barley to be suited for malting must have specific characteristics, such as grain size, husk, starch, and protein contents. It is known that the higher the protein content, the lower the starch (Fox, 2008). Brazilian law states that barley to be considered appropriate for brewing use must have up to 12% protein content (Brasil, 1996)

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