REDEC2014 1570013815 Industrial byproducts valorization through energy saving processes. Alkaline extraction of polyphenols from vine shoots Hiba N. Rajha, Nagham Abou Jaoude, Nicolas Louka and Richard G. Maroun* Centre d'Analyses et de Recherche, UR TVA Faculte des Sciences Universire Saint-Joseph Beirut , Lebanon *corresponding author: richard.maroun@usj.edu.lb Abstract- Vine shoots are viticulture byproducts recently valorized as important sources of polyphenols. These are powerful natural antioxidants used in several industrial applications. The aim of this work is to intensify polyphenol extraction from vine shoots (Syrah variety) using energy saving techniques. In this study, we chose to work with green solvent and in absence of organic solutions. The effect of N aOH concentrations (0, 1, 10, 100 and 1000 mM) on polyphenol extraction was studied. Polyphenol concentrations (Folin- Ciocalteu) and diffusion coefficients (Fick's second law) were calculated The radical scavenging activity (DPPH assay) of extracts was determined. Polyphenol identification and quantification were conducted by High Performance Liquid Chromatography (HPLC). The maximal polyphenol yield (5 mg GAE/g of dry matter (DM)), diffusion coefficient (9 x 10 -12 m 2 /s), radical scavenging activity (62 %) and the maximum molecular diversity were obtained using 1000 mM NaOH solutioJL We hereby propose an environmentally friendly procedure to valorize industrial waste using green technology, leading to the recovery of target compounds and their recycling inside food chain. Keywords- Energy saving; Byproducts valorization; Vine shoots; Polyphenols extraction; Green solvent; Antiradical activity; HPLC. l.INTRODUCTION Agricultural and forestry biomas s have been used for centuries as valuable energy sources [1]. Vine shoots are agriculture byproduct s resulting from vine pruning. Till recentl y, they had no eco nomic value as they w ere traditionally used for heating or thrown on the ground to rot [2]. Several studies were condu cted to valorize vine shoots for their polyphenol content, and thus heighten their economic value. Chemical composition of vine shoots depends on the Vi tis vinife ra variety, its vegetation period, its growing conditions and the occurrence of plant di s eas e [3]. Vine shoot s are a rich source of polyphenols, particularly stilbenoids. Thes e play a major role in defense reactions by acting as phytoalexins [4]. Resveratrol, the leading compound of the stillbenoids family, i s a polyphenol that demonstrated to have a large spectrum of biological effects. It has antioxidant and cardioprotecti on capacities, anticancer activities , anti-inflammatory effects, and es trogenic/antiestrogenic properties [5- 8]. Likewis e, phenoli c Eugene Vorobiev UTC/ESCOM, EA 4297 TIMR Departement de Genie des Procedes Industriels Laboratoire Transformations Integrees de la Matiere Universire de Technologie de Compiegne Compiegne, France acids were identified in vine shoots, namely, ferulic acid. The latter has received much attention since it was found to be one of the effective components in Chinese medicinal herbs [9]. The extraction process of bioactive compounds from their natural source is an important step. It permits the subsequent utilization of these compounds as ingredients or food additives in many industrial products such as pharmaceuticals, nutraceuticals and cosmetics [10]. Many experimental parameters are likely to influence the extraction process, amongst which temperature, extraction time, solvent composition, and solvent to solid ratio. The combination of organic s olvents and relati vely high te mperatur es (50 - 70 °C) are widel y used in literature in order to enhance the extraction of bioactive molecules from different food matrices [11-18]. The objective of this study i s to ameliorate polyphenol extracti on from vine shoots without using organic sol vents and to substitute them by green solvents such as NaOH/water mixtures , with a relatively low maceration temperature and diffusion time. The valorization of thos e industrial was tes will therefore be conducted with an energy s aving procedure. Nowaday s , the main purpos e of green technology is conserving natural environments and res ources by redu cing the negative human implication [19]. The decrease of organic solvents use in industrial applications is therefore an adaptation of such strategy. In addition, harsh organi c s olvent s are expens ive and have negative effect s on the environment and human health [20]. In this work, us ing a green technology, we were able to si gnificantly ameliorate polyphenol extraction from vine shoots. The total quantity of polyphenols and their effective diffusion in the solvents were studied. The effect of alkaline conditions on the antioxidant activity of pol yphenol extract s was determined and the diversity of the compounds was characterized using Hi gh-Perf ormance Liquid Chromatography (HPLC). The optimal experimental parameters were s ettled to produ ce highly bioactive vine shoot extracts through an environm ent-friendl y and energy s aving procedure. II. MATERIALS AND METHODS 1) Raw Material The Viti s Vinife ra Syrah shoot s used in thi s study were prov ided by The Society Chateau KEFRAYA, Beqaa,