Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem Development of novel high-selective extraction approach of carotenoproteins from blue crab (Portunus segnis) shells, contribution to the qualitative analysis of bioactive compounds by HR-ESI-MS Marwa Hamdi a, ⁎ , Rim Nasri a , Nawel Dridi a , Suming Li b , Moncef Nasri a a Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National Engineering School of Sfax, B.P. 1173, 3038 Sfax, Tunisia b European Institute of Membranes, UMR CNRS 5635, University of Montpellier, Place Eugene Bataillon, 34095 Montpellier Cedex 5, France ARTICLE INFO Keywords: Portunus segnis shells Carotenoproteins Enzymatic extraction Chemical extraction HR-ESI-MS ABSTRACT Carotenoids, natural pigments, are a group of chemically heterogeneous molecules, present in numerous tax- onomical clusters. Because of their various bioactivities, carotenoids are day-by-day applied in numerous fields. The present work aimed to investigate an efficient extraction process of carotenoids from blue crab shells and their identification by HR-ESI-MS technique. In this context, different methods (enzymatic, maceration, Soxhlet, etc.) and solvents (variable polarity index) were tested. Maceration using the binary system hexane/isopropanol (50/50) was found to be the most efficient process, producing high carotenoids content and low total phenolic and soluble protein amounts (p < 0.05). When combined with an enzymatic pretreatment, this procedure was found to be remarkably (p < 0.05) more efficient and selective especially towards astaxanthin (p < 0.05). The HR-ESI-MS identified 23 compounds, depending on the adopted extraction approach. The compounds identified may have potential for applications in food or pharmaceutical industries. 1. Introduction With exceptional biodiversity, marine organisms have developed unique properties and bioactive compounds compared to terrestrial sources. Consumption of aquatic foods has increased overall over the last few decades, due to a better understanding of their health benefits and the positive image of seafood products among consumers (Ketnawa et al., 2016). However, only 50–60% of marine resources are used for direct human consumption and a large proportion of waste is discarded or used for the production of protein-rich foods for animals mainly as fishmeal and fertilizer (Shahidi & Ambigaipalan, 2015). Thus, due to economic and technological developments, a multitude of new natural marine products have been discovered, transforming co-products (skin, head, viscera, carapace, etc.) into products with high added value (Hamed, Özogul, & Regenstein, 2016). Among marine by-products, crustacean shells (crabs and shrimps) can serve as a potential biological matrix for the extraction of compounds of interest. Crustacean exos- keletons are characterized by a high content of bioactive substances such as chitin/chitosan, bioactive peptides, carotenoids, etc. (Cahu et al., 2012; Senphan, Benjakul, & Kishimura, 2014). Carotenoids belong to the chemical family of tetraterpenoids and have an aliphatic or acyclic structure. The basic unit of the structure of these pigments is the isoprene, consisting generally of eight isoprene units (C5). Carotenoids are highly unsaturated hydrocarbons having a common biochemical origin similar to fatty acids. Carotenoids include carotenes (simple hydrocarbons mainly in α and β forms) and xan- thophylls (derived from carotenes by the addition of oxygen atoms: astaxanthin, canthaxanthin, flavoxanthin, lutein, etc.) (Martins & Ferreira, 2017; Zaghdoudi, 2015). More than 700 carotenoids have been isolated and identified in nature, usually responsible for the red, yellow, and orange colors of fruits, vegetables and flowers but also animals consuming these latter (Yolmeh & Khomeiri, 2017). Because of their various bioactivities, mainly antioxidant, anti- microbial, anticancer, immunomodulatory, antidiabetic and anti-in- flammatory effects (Ikeuchi, Koyama, Takahashi, & Yazawa, 2006) carotenoids and carotenoproteins are widely applied as a colorant in diets, aquaculture, and in the cosmetics and pharmaceutical industries (Ketnawa et al., 2016; Sowmya & Sachindra, 2012). In this context, techniques have been developed and applied for the extraction of car- otenoids from crustacean shells in the form of carotenoproteins, such as organic solvents extraction (Cardenas-Toro et al., 2015; Babu, Chakrabarti, & Sambasivarao, 2008), lactic fermentation (Armenta- López, Guerrero, & Huerta, 2002), oil process extraction (Sowmya & Sachindra, 2012), super critical carbon dioxide extraction (Cardenas- https://doi.org/10.1016/j.foodchem.2019.125334 Received 21 January 2019; Received in revised form 25 July 2019; Accepted 6 August 2019 ⁎ Corresponding author. E-mail address: marwahamdi50@yahoo.fr (M. Hamdi). Food Chemistry 302 (2020) 125334 Available online 07 August 2019 0308-8146/ © 2019 Elsevier Ltd. All rights reserved. T