Hop by-products: pharmacological activities and potential application as cosmetics

Hops (Humulus lupulus L.) are known worldwide as a raw material in beer production due their flavor and preservative values. The beneficial properties of the plant have been mostly associated with the female hop inflorescences (cones), which is also the part used in the brewing industry. However, some studies indicate the presence of compounds associated with health benefits in the vegetative parts of hops or small-caliber cones, which discarded in hop collection. Moreover, large quantities of by-products remain in the forms of spent grains and spent hops/hot trub and are produced by breweries raising environmental and economic sustainability concerns. This review focuses on the phytochemicals and biological and pharmacological activities of hop and their potential use in skin care products and also intends to explore the potential of the hop’ discarded parts and brewery industry by-products for production in the cosmetics industry.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020, UIDP/00690/2020 and EXPL2021CIMO_06) and SusTEC (LA/P/0007/2020).