Acclimation of Humulus lupulus in Brazil: development, physiology and metabolomics

Abstract

Female hop inflorescences (Humulus lupulus L.) have glandular trichomes that secrete a variety of secondary metabolites that are being used in sedative and cosmetic products, such as phytoestrogens and food supplements. However, most of the commercialization of hops is used in the brewing industry to aromatize and produce bitterness in beer due to the presence of bitter acids and volatile oils. Although the brewing sector plays an important role in the economy of the country, with Brazil being the third largest beer producer and the sector, which accounts for 1.6% of PIB, part of the raw material for beer production is imported. All hops in the country are imported, mainly from Germany and United States. Although some hop producers have already had success producing it in Brazil, little is known about the acclimation of this temperate climate native plant in our tropical climate. Therefore, the goal of this proposal besides evaluating the development and production of inflorescence, which are interesting to pharmaceutical industry and breweries, is also to study the physiological performance (gas exchange, chlorophyll fluorescence, synthesis and activity of enzymatic antioxidant mechanisms and non-enzymatic) and metabolomics (using LC-MS) of four hop cultivars grown under tropical climate, in Ribeirão Preto, SP. The information conceived by this unheard-of interdisciplinary study will allow to go deeper into the knowledge about the cultivation and quality of hop produced in Brazil, and will add valuable information to future producers. The hypothesis are that (i) the high temperature, characteristic of tropical climate, increases the oxidative stress and consequently the enzymatic activity and non-enzymatic antioxidants; and (ii) that the tropical climate conditions provide an increase in bitter acids and volatile oils. Besides scientific production, it is expected that this project contributes to the body of knowledge and can be used by hop producers in Brazil, being spread to interested companies, such as breweries and pharmaceutical industries. (AU)