Determination of the influence of malting parameters on the water-extractable arabinoxylan content of wheat (triticum aestivum), rye (secale cereale), and spelt wheat (triticum aestivum spp. spelta)

Water-extractable arabinoxylans (WEAX) are an interesting component of malted cereals for two reasons. On the one hand, they have beneficial attributes for the colonic and overall health of consumers and are a fermentable component of dietary fiber in the human diet. On the other hand, they have a negative impact on the production process of malt-based beverages. In this study, the influence of the malting parameters germination temperature, germination time, and moisture content on the resulting WEAX content of malts produced from wheat (Triticum aestivum), rye (Secale cereale), and spelt wheat (T. aestivum spp. spelta) was investigated. The malting parameters were varied according to a design of experiment (DOE) approach (central composite design), and their influence on WEAX content was analyzed using a DOE software package (Design-Expert 7). WEAX levels ranged from 2.38 to 2.92 g/100 g (dry weight basis [dwb]) in malted rye (R² = 0.914), 0.76 to 1.28 g/100 g (dwb) in malted spelt wheat (R² = 0.823), and 1.13 to 1.58 g/100 g (dwb) in malted wheat (R² = 0.815). In rye and wheat, WEAX correlated negatively with wort viscosity, and a negative tendency was observed for spelt wheat.