Biorefinery and Stepwise Strategies for Valorizing Coffee By-Products as Bioactive Food Ingredients and Nutraceuticalials  
[PERSON]  
1 Department of Agricultural Chemistry and Food Science, Faculty of Sciences, Universidad Autonoma de Madrid, C/[PERSON], 7, 28049 Madrid, Spain; [PERSON]ADDRESS](M.R.-H.); [EMAIL_ADDRESS](Y.A. ); [EMAIL_ADDRESS](A.G.-R.); [EMAIL_ADDRESS](V.B. ); [EMAIL_ADDRESS](S.C.); [EMAIL_ADDRESS](C.B.) [PERSON]  
1 Department of Agricultural Chemistry and Food Science, Faculty of Sciences, Universidad Autonoma de Madrid, C/[PERSON], 7, 28049 Madrid, Spain; [PERSON]ADDRESS](M.R.-H.); [EMAIL_ADDRESS](Y.A. ); [EMAIL_ADDRESS](A.G.-R.); [EMAIL_ADDRESS](V.B. ); [EMAIL_ADDRESS](S.C.); [EMAIL_ADDRESS](C.B.) [PERSON]  
1 Department of Agricultural Chemistry and Food Science, Faculty of Sciences, Universidad Autonoma de Madrid, C/[PERSON] y Valiente, 7, 28049 Madrid, Spain; [PERSON]ADDRESS](M.R.-H.); [EMAIL_ADDRESS](Y.A. ); [EMAIL_ADDRESS](A.G.-R.); [EMAIL_ADDRESS](V.B. ); [EMAIL_ADDRESS](S.C.); [EMAIL_ADDRESS](C.B.) Footnote 1: [[https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci)]([https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci))  
Footnote 2: [[https://www.mdpi.com/journals/pdf/12/2018/](https://www.mdpi.com/journals/pdf/12/2018/)]([https://www.mdpi.com/journals/pdf/12/2018/](https://www.mdpi.com/journals/pdf/12/2018/))  
0.2 L cups of coffee per day [1]. The personal global consumption ranking is led by Scandinavian countries, headed by Finnish people with a yearly consumption of around 9.4 kg of roasted coffee per capita (equivalent to 6-8 cups per day). This superior demand turns coffee beans into one of the globe's top-traded agro-industrial products. According to the International Coffee Organization, about 171.3 million 60 kg bags of coffee beans are estimated to be produced in 2022/2023, following a robust increasing biannual trend in forthcoming years due to the endless rising of consumer demand. Surprisingly, the mentioned production results insufficiently cover the predicted consumption estimations for a second consecutive year, i.e., around 178.5 million bags [2], which could explain the 1.9% volume growth expected for the coffee market in 2024 [2]. This agro-industrial and socioeconomic paradigm rationalizes the worldwide concern relative to the environmental impact of coffee cultivation and manufacturing, owing to the notable amount of by-products delivered by this food sector. Waste management is one of the most challenging problems we currently handle worldwide. Presently, food systems are highly inefficient since around one-third of the food produced is wasted and not consumed [3]. Food is lost or wasted at every stage of the food supply chain, from farming to consumption. Therefore, to ensure sustainable management of food waste, food by-products should be utilized before they become waste, thus increasing the food system's sustainability which constitutes a milestone of the United Nations' Sustainable Development Goals (SDGs). The SDGs seek to restructure the agriculture and food systems to decrease hunger, achieve food security, and improve nutrition while reducing food waste and losses along supply chains [4]. A sustainable food system delivers food security and nutrition without endangering the economic, social, and environmental foundations for producing safe and nutritious foods for future generations. Consequently, the food system generates economic value-added benefits (economic sustainability), has widespread social benefits including nutritional and health benefits, and is equitable in distributing the economic value-added (social sustainability) plus a favorable or neutral environmental effect (environmental sustainability) [5]. Undoubtedly, the coffee agro industry must also face this challenge focused on waste management. Indeed, coffee by-products from wet and dry processing--coffee husk, parchment, pulp, mucilage, and silverskin--represent nearly 50% of the coffee cherry on a dry weight basis [2].