Cosmetics 2021, 8, 109. https://doi.org/10.3390/cosmetics8040109 www.mdpi.com/journal/cosmetics Review Valorization of Wine‐Making By‐Products’ Extracts in Cosmetics Israa Hoss 1,† , Hiba N. Rajha 1,2, * ,† , Rindala El Khoury 1 , Sahar Youssef 1 , Maria Letizia Manca 3 , Maria Manconi 3 , Nicolas Louka 1 and Richard G. Maroun 1 1 Centre d’Analyses et de Recherche, Unité de Recherche Technologies et Valorisations Agro‐Alimentaire, Faculté des Sciences, Université Saint‐Joseph de Beyrouth, P.O. Box 17‐5208 Riad El Solh, Beirut 1104 2020, Lebanon; israa.hoss@net.usj.edu.lb (I.H.); rindala.khoury@net.usj.edu.lb (R.E.K.); sahar.youssef@tamerholding.com (S.Y.); nicolas.louka@usj.edu.lb (N.L.); richard.maroun@usj.edu.lb (R.G.M.) 2 Ecole Supérieure d’Ingénieurs de Beyrouth (ESIB), Université Saint‐Joseph de Beyrouth, CST Mkalles Mar Roukos, Riad El Solh, Beirut 1107 2050, Lebanon 3 Centre for Nanobiotechnology Sardinia CNBS, Department of Scienze della Vita e dell’Ambiente, University of Cagliari, 09124 Cagliari, Italy; mlmanca@unica.it (M.L.M.); manconi@unica.it (M.M.) * Correspondence: hiba.rajha@usj.edu.lb; Tel.: +961‐78‐821‐568 † Both authors equally contributed. Abstract: The increased demand for conscious, sustainable and beneficial products by the consum‐ ers has pushed researchers from both industries and universities worldwide to search for smart strategies capable of reducing the environmental footprint, especially the ones connected with in‐ dustrial wastes. Among various by‐products, generally considered as waste, those obtained by winemaking industries have attracted the attention of a wide variety of companies, other than the vineries. In particular, grape pomaces are considered of interest due to their high content in bioac‐ tive molecules, especially phenolic compounds. The latter can be recovered from grape pomace and used as active ingredients in easily marketable cosmetic products. Indeed, phenolic compounds are well known for their remarkable beneficial properties at the skin level, such as antioxidant, anti‐ aging, anti‐hyperpigmentation and photoprotective effects. The exploitation of the bioactives con‐ tained in grape pomaces to obtain high value cosmetics may support the growing of innovative start‐ups and expand the value chain of grapes. This review aims to describe the strategies for re‐ covery of polyphenols from grape pomace, to highlight the beneficial potential of these extracts, both in vitro and in vivo, and their potential utilization as active ingredients in cosmetic products. Keywords: cosmetics; grape pomace; phenolic compounds; antioxidants; extracts; natural active in‐ gredient; sustainable development 1. Introduction Valuable phenolic compounds can be recovered from several edible fruits and vege‐ tables, but also from different food by‐products such as citrus fruits, orange peels [1–3], lemon peels, pomelo peels [3], grapefruit peels [4] and olive leaves [5–7]. in addition to pomegranate fruits peels and seeds [8–10], peach pomace [11] and viticulture by‐prod‐ ucts, in particular vine shoots [12–17] and winemaking by‐products, especially grape pomace [18–22]. Grape by‐products derived from the winery wastes consist mainly of vine stems, grape pomace and wine lees. Grape pomace is one of the most important residues, con‐ stituting between 20 and 25% of the initial grapes’ weight and composed of 25% seeds, 25% stalks and 50% skins [23,24]. Grape pomace is generated during the winemaking pro‐ cess, after the fermentation step in the case of red grapes, and prior to it in the case of white grapes (Figure 1) [25]. Considering that 35.9 million tons of grapes are pressed Citation: Hoss, I.; Rajha, H.N.; El Khoury, R.; Youssef, S.; Manca, M.L.; Manconi, M.; Louka, N.; Maroun, R.G. Valorization of Wine‐Making By‐Products’ Extracts in Cosmetics. Cosmetics 2021, 8, 109. https://doi.org/10.3390/ cosmetics8040109 Academic Editor: Piera Di Martino Received: 20 October 2021 Accepted: 16 November 2021 Published: 18 November 2021 Publisher’s Note: MDPI stays neu‐ tral with regard to jurisdictional claims in published maps and institu‐ tional affiliations. Copyright: © 2021 by the authors. Li‐ censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con‐ ditions of the Creative Commons At‐ tribution (CC BY) license (https://creativecommons.org/licen‐ ses/by/4.0/).