Chapter 15 - Assessment of barley quality

Abstract

Barley cultivars and breeding lines are evaluated for malting and nutritional quality in the Washington State University barley breeding program as the development of ‘multipurpose’ two- and six-row varieties is the overall breeding objective. Early generation screening for malting quality has been done successfully by micromalting procedures in the laboratory followed by larger scale tests in USDA and industry facilities. Efforts to breed proanthocyanidin-free (ant) barley grain are under way to overcome the chill haze problem in beer. Fifty-two ant mutants have been induced thus far in American varieties and initial agronomic and quality evaluations have been favorable. Nutritional quality of barley grain is assessed through feeding trials, primarily with chicks. The determination of limiting factors in barley utilization by non-ruminants has concentrated on β-glucans, fiber and lysine. β-glucans appear to be negative factors based on initial correlated responses. Increasing grain lysine availability is being approached by seeking and accumulating higher lysine-containing hordeins (the most prominent protein fraction in the grain) hopefully to overcome the prevailing shrunken endosperm association in high lysine barley conditioned by the major genes in use worldwide. Nutritional evaluations of straw samples of 30 barley varieties indicated that wide variation occurs in protein, fiber and in vitro dry matter digestibility, suggesting implications important to ruminant nutrition and barley breeding.