The application of antifungal protein (AFP) from Aspergillus giganteus to the malting process and its effect on malt and corresponding beer

Microbiology Session
Deliang Wang, China National Institute of Food and Fermentation Industries
Co-author(s): Yue Yuan, Division of Food Sciences, Xinjiang Agricultural University, China; Zhiping Lin and Jiafeng Chao, Technical Research Center of Beijing Yanjing Brewery Group Co. Ltd., China

ABSTRACT: Filamentous fungi infections in malting barley can have severe effects on malt quality and fermentation performance of brewing yeast, such as reduction of barley germination rate, induction of premature yeast flocculation (PYF), beer gushing, and off-flavors. In addition, most filamentous fungi, especially Fusarium, can produce a series of mycotoxin in barley (deoxynivalenol [DON], nivalenol, T-2, HT-2, diacetoxyscirpenol, zearalenone, aflatoxins, ochratoxin A, and fumonisins), and they may have a great negative influence on malt quality and food safety. In this study, the antifungal protein (AFP) was isolated from the fermentation supernate of Aspergillus giganteus identified by a series of experiments, such as morphologic observation and molecular biology. Its application and the influence of AFP on malting were analyzed on laboratory and pilot scales. And, its parameters from corresponding beer production were also tested. Results showed that AFP can effectively and significantly inhibit the growth of most kinds of filamentous fungi on barley and reduce both the residues of mycotoxin and corresponding gushing potential; however, in comparison to the control, the data also showed that its application has no negative effects on fermentation performance during beer production.

Deliang Wang is the director of the Brewing Engineering Technology Department (BETD), a subdivision of the China National Research Institute of Food & Fermentation Industries (CNRIFFI). Since Deliang graduated, he has been acting as an applied scientist presiding over the technical consultants and cooperative projects with many large Chinese breweries, such as Anheuser-Busch InBev, Yanjing brewery (top 8 in the world), Kingstar brewery (no. 12 in the world), Zhujiang brewery (no. 15 in the world), Kingway brewery, Yinmai brewery, etc. The beer volume produced by these breweries is more than one-third of the total Chinese beer production each year. Besides domestic enterprises, Deliang is also responsible for cooperation with international partners, such as DSM food limited, ICT-Czech Republic, VLB-Berlin, etc. Deliang has also published many articles at home and abroad, and some articles have been published in the Journal of the American Society of Brewing Chemists. Deliang is a member of both ASBC and MBAA.