Food & Function PAPER Cite this: Food Funct., 2021, 12, 7428 Received 12th February 2021, Accepted 1st June 2021 DOI: 10.1039/d1fo00457c rsc.li/food-function Bioactive extracts from persimmon waste: influence of extraction conditions and ripeness† Daniel Alexander Méndez, a María José Fabra, a,b Irene Falcó, a Gloria Sánchez, a Paula Aranaz, c,d Ariane Vettorazzi, e Albert Ribas-Agustí, f Carlos Javier González-Navarro, c Massimo Castellari, f Antonio Martínez-Abad a,b and Amparo López-Rubio * a,b In this work, a bioactive persimmon extract was produced from discarded fruits. A central composite design was used to evaluate the effect of different extraction parameters and ripeness stages of persim- mon fruits on the total phenolic content and antioxidant activity of the resulting extracts. Significantly greater phenolic contents were obtained from immature persimmon (IP) fruits. The optimum IP extract with the conditions set by the experimental design was industrially up-scaled and its composition and functional properties were evaluated and compared with those obtained under lab-scale conditions. Both extracts contained significant protein (>20%) and phenolic contents (∼11–27 mg GA/g dry extract) and displayed significant antiviral activity against murine norovirus and hepatitis Avirus. Moreover, the extract showed no toxicity and significantly reduced the fat content and the cellular ageing of Caenorhabditis elegans (C. elegans) without affecting the worm development. These effects were mediated by down- regulation of fat-7, suggesting an anti-lipogenic activity of this extract. 1. Introduction According to the Food and Agriculture Organization (FAO), around 14 percent of the food produced worldwide every year is lost from the post-harvest stage to the retail stage and, of this, fruits and vegetables have the second highest wastage rate of the different commodity groups after roots and tubers. 1 The reduction of food loss and waste is an important target of the Sustainable Development Goals (SDGs), relating to food security, nutrition and environmental sustainability. To date, most agro-industrial wastes have been extensively used as a source of fuel, animal feed or organic fertilisers. 2 However, there is growing interest in the valorisation of agro- industrial by-products and wastes as abundant, cheap and renewable sources of high added value molecules with specific functional properties. 3,4 Persimmon (Diospyros kaki Thunb.) fruits are rich in various nutrients and phytochemicals, including carbo- hydrates, vitamins, proanthocyanidins, flavonoid oligomers, tannins, phenolic acids, dietary fibre and carotenoids, which significantly contribute to their taste, colour, and nutritional and medicinal value. 5 Although China is by far the larger pro- ducer, a significant amount of persimmon is also produced in Spain, being the main exporter of the fruit, particularly in Europe. 6 Currently, the seasonality and overproduction, together with problems associated with storage, ripening pro- cesses, fruit disease and stringent standard demands in terms of fruit appearance, give rise to huge amounts of discarded fruits at different stages of ripeness, which are estimated to be around 5–20% of the fruit harvested. 7 In this sense, and given the existing evidence related to the beneficial functional attri- butes derived from phytochemicals (and more specifically polyphenols) present in the persimmon fruits, 6,8 a plausible strategy for their valorisation can be obtaining polyphenol-rich extracts from the discarded fruits. It is also well known that composition changes with fruit ripeness and, thus, exploring these functional attributes in different stages of development can also be helpful to determine the best ripening stage if aiming at this type of valorisation. Although a few research studies have focused on obtaining purified tannins from persimmon pulp, 9,10 from an appli- † Electronic supplementary information (ESI) available. See DOI: 10.1039/ d1fo00457c a Food Safety and Preservation Department, Institute of Agrochemistry and Food Technology (IATA-CSIC), Valencia, Spain. E-mail: amparo.lopez@iata.csic.es b Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy- Spanish National Research Council (SusPlast-CSIC), Madrid, Spain c Center for Nutrition Research, University of Navarra, Pamplona, Spain d Navarra Institute for Health Research (IdiSNA), Pamplona, Spain e Department of Pharmacology and Toxicology, Universidad de Navarra, Pamplona, Spain f Institute of Agriculture and Food Research and Technology, Food Industries, Finca Camps i Armet, Monells, Spain 7428 | Food Funct. , 2021, 12, 7428–7439 This journal is © The Royal Society of Chemistry 2021 Open Access Article. Published on 01 June 2021. Downloaded on 2/20/2022 4:28:23 AM. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. View Article Online View Journal | View Issue