Enzymatic degradation of prickly pear seed (PPS)/Polyhydroxy (butyrate-co-valerate) (PHBV) biocomposite Rebiha Bellache a, ⁎ , Dalila Hammiche a , Azzedine Bettache b , Amar Boukerrou a a Laboratoire des Matériaux Polymères Avancés, Département Génie des Procédés, Faculté de Technologie, Université de Bejaia, Algeria b Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Algeria article info Article history: Available online 13 January 2022 Keywords: Poly-hydroxybutyrate-co-valerate Prickly pear seed Composite Enzymes Degradation abstract This paper presents some interesting results on the physic-chemical and morphological properties of the enzymatic degradation of prickly pear seed vegetable fiber (PPS) enhanced Polyhydroxy(butyrate-co-vale rate) (PHBV) biocomposite. It is shown that the b-glucanase enzyme at pH = 5,5 accelerated the degrada- tion of PHBV/PPS biocomposite compared to PHBV as well as compared to a-amylase (pH = 7) and pro- tease (pH = 8) enzymes, which is confirmed by the significant weight loss in b-glucanase. The Fourier transform infrared spectroscopy analysis FTIR analysis allowed seeing the decrease of carbonyl group and thus its hydrolysis and degradation by ester chain cleavage. Morphological analysis is evaluated by scanning electron microscope (SEM); this analysis also confirms the enzymatic degradation by the presence of small holes on the surface of PHBV/PPS biocomposite immersed in the enzymatic solution of b-glucanase. In addition, the effect of the incorporation of the PPS fiber plays an important role in this degradation. Copyright Ó 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Polymer & Mediterra- nean Fiber International Conference’2021. 1. Introduction Hydrolysis reactions may be catalyzed by enzymes, it is a bio- logical catalyst, i.e., it accelerates the reaction rates [1]. The enzy- matic degradation of polymers by hydrolysis is a two-step process: first, the enzyme binds to the polymer substrate then sub- sequently catalyzes a hydrolytic cleavage. During degradation, extracellular enzymes from microorganisms break down complex polymers yielding short chains or smaller molecules, e.g., oligo- mers, dimers, and monomers that are smaller enough to pass the semi-permeable outer bacterial membranes. The process is called depolymerization. These short chain length molecules are then mineralized into end products e.g. CO 2 ,H 2 O, or CH 4 which are uti- lized as carbon and energy source, the degradation is called miner- alization [2]. Poly(hydroxybutyrate-co-hydroxyvalerate), abbreviated usu- ally as PHBV or PHBHV, originates from the insertion of 3- hydroxyvalerate (HV) units to the PHB biopolymer, it is obtained through bacterial fermentation [3], it belongs to the polyhydrox- yalkanoates family and it is used as a basic matrix in this work. In addition, to obtain a biocomposite, prickly pear seed (PPS) is added to this matrix as a vegetal reinforcement. According to the scientific literature, only few studies report the use of PPS for preparing biocomposites [4]. This study aims to formulate a biocomposite based on PHBV and PPS and to study its biodegradability in enzymatic medium. To support this study, physico-chemical characterizations and morphological aspects are carried out. 2. Materials and methods 2.1. Materials PHBV copolymer used in this work was supplied by Tianah Bio- logical materials Co. LTD. (China) with a molar ratio of 92:8 (HB: HV). It was commercialized in the form of pellets under the grade name ENMAT Y1000P. Prickly pear seed (PPS) was supplied by the company Thafath Tizi-Ouzou, Algeria. https://doi.org/10.1016/j.matpr.2021.12.419 2214-7853/Copyright Ó 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Polymer & Mediterranean Fiber International Conference’2021. ⁎ Corresponding authors. E-mail address: rebiha.bellache@univ-bejaia.dz (R. Bellache). Materials Today: Proceedings 53 (2022) 113–116 Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr