## 4 Conclusions  
This research assessed the cross-cultural perception and liking of butters produced by three different feed systems. Overall, Irish, German, and USA consumers did not discriminate their overall liking of butters based on feed system, although some clear cultural differences were evident. Familiarity was postulated to contribute to differences in appearance liking and color liking by USA consumers, where the indoor TMR feed system scored highest. However, this did not impact overall liking of butter produced from pasture (FS-GRSS and FS-CLVR) by USA consumers. Both Irish and German consumers rated the color intensity of the pasture butters (FS-GRSS and FS-CLVR) higher than FS-TMR butter. German consumers also found that pasture (FS-GRSS and FS-CLVR) butter was more salty and that FS-TMR butter was firmer. It seems plausible that the texture and salty differences noted by German consumers are likely related to differences in their FA profile, which directly impacts on texture, but also indirectly on salty perception as the greater unsaturated FAs lower the melting point in the pasture butters. RDA by Irish and German assessors also identified important cross-cultural differences--German assessors perceived FS-GRSS butter as significantly more sour and milky, and scored FS-TMR butter higher for melt in the mouth, in comparison to Irish assessors. Both Irish and German assessors found that FS-TMR butter had less yellow color in agreement with the consumers, and German assessors found it darker than Irish assessors. Both Irish and German assessors found that FS-CLVR butter was the most intense yellow. USA panelists also found that color intensity ranged from FS-CLVR > FS-GRSS > FS-TMR. These results correlate with previous studies highlighting the impact of carotenoids, specifically \(\beta\)-carotene on the yellow color of pasture-derived dairy products. The trained USA panelists also found that a grassy flavor was highest in FS-GRSS butter but absent in FS-TMR butter, and that FS-CLV butter had a mothball attribute absent in FS-GRSS and FS-TMR butter. Volatile analysis identified a number of compounds that were statistically different based on diet--aldehydes, ketones, acids, toluene and ethyl acetate. The aldehydes, ketones and acids in the butter from the pasture diets may be influencing the grassy, milky and sour flavors, as perceived by USA and German consumers. Diacetyl may also be influencing enhanced buttery aroma, as perceived by Irish assessors in pasture (FS-GRSS and FS-CLVR) butter.  
This study demonstrates that different feed systems affect cross-cultural perception of butter and that familiarity of products from specific feeds systems is a factor, but that it does not adversely impact butter acceptance in terms of overall liking within these cultural groups.  
The following are available online at [[http://www.mdpic.com/2304-8158/9/12/1767/sl](http://www.mdpic.com/2304-8158/9/12/1767/sl)]([http://www.mdpic.com/2304-8158/9/12/1767/sl](http://www.mdpic.com/2304-8158/9/12/1767/sl)), Table S1: Sensory terms for consumer study; in relation to Hedonics, Intensity Scales and for Just About Right assessment; Table S2: Attribute list presented to panelists for Ranked Descriptive Analysis by assessors.  
Funding acquisition, M.G.O. and K.N.K.; conceptualization, K.N.K. and E.C.G.; methodology, T.S., M.D., M.G.O. and K.N.K.; resources, T.S., M.D., S.F., M.G.O., J.P.K. and K.N.K.; project administration, M.G.O., J.P.K. and K.N.K.; formal analysis, E.C.G., T.S., M.D., M.G.O., J.P.K. and K.N.K.; investigation, E.C.G. and T.F.O.; data curation, E.C.G., T.S., T.F.O., M.D. and S.F.; writing--original draft preparation, E.C.G.; writing--review and editing, M.G.O., J.P.K. and K.N.K.; supervision, M.G.O., J.P.K. and K.N.K. All authors have read and agreed to the published version of the manuscript.  
Department of Agriculture, Food and the Marine, Ireland: 14F 812.  
The authors declare no conflict of interest.