Repeatability of mice consumption discrimination of wheat (Triticum aestivum L.) varieties across field experiments and mouse cohorts

Authors: Kiszonas, Alecia; FUERST, E - Washington State University; Morris, Craig

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/6/2015
Publication Date: 7/16/2015
Publication URL: http://handle.nal.usda.gov/10113/61109
Citation: Kiszonas, A., Fuerst, E.P., Morris, C.F. 2015. Repeatability of mice consumption discrimination of wheat (Triticum aestivum L.) varieties across field experiments and mouse cohorts. Journal of Food Science. 80:S1589-S1594.

Interpretive Summary: Interest in the health benefits of consuming whole grains has focused attention on some of the possible barriers to increased whole grain consumption. In the case of wheat (Triticum aestivum L.), undesirable flavors have been associated with the bran which is included in whole wheat products. The inclusion of bran (the outer layers of the wheat kernel) is what distinguishes whole wheat flour from refined white flour. As such, bran is the major contributor to the often objectionable flavor of whole wheat bread and other whole wheat products. To study one aspect of this subject, we have explored the use of the house mouse (Mus musculus L.) as an efficient model system to discern flavor differences amongst grains of different wheat varieties. Our work to date indicates that mice are highly consistent and discriminating in their consumption of various wheat grains. A key question regarding the continued development of this model system involves the reproducibility of mouse flavor preferences and consistency of wheat variety flavor. The objective of this study was to examine the consistency or repeatability of consumption (ostensibly taste) discrimination using the same varieties of wheat across three crop years and two mouse cohorts. In all cases, the mice were consistent across experiments and cohorts as to the “winners” and “losers” of each wheat pairing in the single-elimination tournament style of the experiment. The two cohorts were particularly consistent in the hard red spring variety pairings, although crop year appeared to have a greater influence on level of taste discrimination. In the hard white spring varieties, because experiment 1 was a different cohort of mice, it is impossible to ascertain whether it was cohort or crop year differences causing the varied levels of consumption preference across variety pairings, although the small number of varieties in the hard white spring portion of the study cannot offer any conclusive evidence of inconsistency or lack of repeatability. The larger number of varieties in the hard red spring portion of the study gives more confidence to the repeatability of taste discrimination and preference studies across cohorts and experiments. As such, the mice consistently preferred the same varieties in each pairing across cohorts and experiment (crop years).

Technical Abstract: Whole grain wheat (Triticum aestivum L.) foods can provide critical nutrients for health and nutrition in the human diet. However, undesirable flavors are often suggested as a barrier to increased whole-grain consumption, yet flavor differences among wheat varieties have not been widely studied. Potential flavor differences among varieties can be examined using the house mouse (Mus musculus L.) as a model system. The present study encompasses three crop years, treated as three separate field experiments, and two cohorts of mice, in order to examine consistency and repeatability of the mouse model and potentially, wheat grain flavor. A single elimination tournament design was used to measure relative consumption preference for hard red spring and hard white spring varieties across all three experiments and two mouse cohorts. Fifteen mice were used in 24-h trials to examine differences in preference among paired wheat varieties until an overall “winner” was established as the most highly preferred variety of wheat. In all three experiment - cohort combinations, the same varieties were preferred as the “winner” of both the hard red spring and hard white spring wheat varieties, Hollis and BR 7030, respectively. Despite the consistent preference for these varieties across experiments, the degree (magnitude) to which the mice preferred these varieties varied across experiments. In the hard white spring wheat varieties, the small number of varieties and confounding effects of experiment and cohort proved inconclusive in repeatability. Conversely, for the hard red spring wheat varieties, consumption preferences were consistent across experiments and mice cohorts. The single-elimination tournament model was effective in providing repeatable results in an effort to more fully understand the mouse model system and possible flavor differences among wheat varieties.