An novel enzyme-linked immunosorbent assay for barley lipid transfer protein as a quality control system of beer

Abstract

Using a polyclonal antibody raised against lipid transfer protein (LTP) purified from barley flour, a new sandwich-type enzyme-linked immunosorbent assay method was developed to detect barley LTP at concentrations of 0.1-10ng/mL. This method showed 0.003% cross reactivity against LTP of wheat and no cross reactivity against that of oats, adlay, and rye. LTP was detected in several foods containing barley, including fermented foods such as vinegar, soybean paste and beer. The LTP content was approximately the same for similar kinds of beer, even for those manufactured at different facilities or on different production days. Controlling and monitoring the LTP content in beer is important, as LTP is not only known as a factor of foam formation and stability, but also as an allergen. Therefore, this detection method of the LTP content may be a useful tool for quality control of beer.