By analyzing the creation and development of the health-enhancing product Becel over more than three decades this article illustrates how techno-scientific frontier processes impacted on the Dutch-British firm, Unilever. The expansion of the scientific frontier led to new insights in the field of cardiovascular diseases, which not only affected the medical community, but also food companies like Unilever. The development of Becel early 1960s - initially as a diet fat, later as a diet margarine – required state-of-the-art food science research. We encountered a growing tension between the scientific techno-scientific frontier processes and the public acceptance of scientific insights. While the researchers’ drive to expand the scientific frontier remained the same throughout three decades, the legitimation of the company’s activities by referring to scientific progress was becoming increasingly difficult. This was not without consequences for Unilever. We argue that this was due to three related processes unfolding in the early 1970s. Scientific debates became public; society at large was losing its faith in science and experts; and finally within Unilever itself: marketing managers and their ideas on how to position Becel became more dominant than those of the laboratory researchers.