Theses and Dissertations at Montana State University (MSU)
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Item Genetic dissection of malt quality in barley: an examination of hydration index and metabolite QTL(Montana State University - Bozeman, College of Agriculture, 2024) Jensen, Joseph Riley; Chairperson, Graduate Committee: Jamie Sherman; This is a manuscript style paper that includes co-authored chapters.Malting barley is a high value crop for American farmers. Through the malting process grain is turned into malt which is primarily used in brewing but can also be a flavor and nutritional additive for the food industry. During the malting process hydration of the endosperm is a rate limiting step resulting in increased time and water usage if a third water immersion is needed during steeping. To better understand the genetics of endosperm hydration we used a genome wide association (GWAS) population to map quantitative trait loci (QTL) for malt quality, hydration index (endosperm hydration), and seed morphology traits. We found six hydration index QTL with three related to seed size (qHYI1H, qHYI3H.a, and qHYI3H.b), two improving malt quality (qHYI2H and qHYI6H), and the last (qHYI7H) wasn't related to any other traits. We then wanted to see the relationship between hydration index and dormancy because dormancy is needed to prevent preharvest sprouting. Preharvest sprouting in malt barley results in extreme price reductions for producers however the dormancy genes needed to prevent this negatively impact malt quality. Using a biparental mapping population we were able to map two hydration index QTL and relate them to the dormancy gene SD2. Our results confirmed SD2 negatively impacts malt quality but when the positive alleles for hydration index are present, they negate dormancy's negative effects on quality. The results from these two studies show hydration index can benefit growers and maltsters with barley and malt production. Our third study looked at metabolite variation in the GWAS population to see if we could identify QTL related to malt flavor. This would help craft malt houses and breweries which are usually in search of unique flavors. We were able to identify 827 metabolite QTL however the most impactful to flavor were amino acid, saccharide, and maltol QTL which totaled 39. The three maltol QTL which are directly related to flavor all co-located with maltol precursors (amino acids and saccharides) showing these QTL would be good targets for marker assisted selection to create maltol variation.Item Controlled sprouting in wheat increases quality and consumer acceptibility of whole wheat bread(Montana State University - Bozeman, College of Letters & Science, 2019) Bummer Johnston, Rachel Elizabeth; Chairperson, Graduate Committee: Michael J. Giroux and Carmen Byker (co-chair); John M. Martin, Carmen Byker-Shanks, Sean Finnie and Michael J. Giroux were co-authors of the article, 'Controlled sprouting in wheat increases quality and consumer acceptability of whole wheat bread' submitted to the journal 'Cereal chemistry' which is contained within this thesis.Intentional sprouting of grain to modify grain products nutritional composition and flavor has been in practice for thousands of years. However, few studies have tested the impact of controlled sprouting on wheat flour functionality and flavor. In this study, grain of nine hard red spring (HRS) wheat (Triticum aestivum L) cultivars was sprouted with the goal of attaining a falling number (FN) value of 200 from a starting FN of 350 seconds. Paired samples of sprouted and sound HRS grain were then assayed for nutritional composition, functionality in bread baking, and in bread taste tests. Sprouting reduced grain hardness and test weight while increasing grain color brightness, yellowness, and redness. Whole sprouted grain flour had twice the alpha amylase activity and a large decrease in flour swelling power relative to sound grain flour. Sprouted flour also contained increased free amino acids and monosaccharides while having decreased sugar alcohol content. Total dietary fiber trended down in the sprouted grain flour while starch content remained unchanged. Whole grain flour color parameters were relatively unaltered by sprouting. Sprouting reduced dough mix times while increasing loaf volume. Sensory panel evaluations demonstrated that testers preferred bread prepared from sprouted grain flour to bread prepared from sound grain while also finding that sprouted grain bread tasted less bitter and grainy while also being perceived as sweeter and moister. The results demonstrate that controlled sprouting of wheat grain could be used to increase whole grain flour functionality in bread baking and consumer acceptability of whole grain foods.