International Journal of Scientific and Research Publications, Volume 11, Issue 7, July 2021 226 ISSN 2250-3153 This publication is licensed under Creative Commons Attribution CC BY. http://dx.doi.org/10.29322/IJSRP.11.07.2021.p11529 www.ijsrp.org Influences of the pH, the liquid/solid ratio, and the mixing of the wastes of mango, passion fruit and Bambara groundnut on the extraction yield of pectin RANDRIAMPENOHAJA A. R. Jens 1-2 , RASOLOHERY Claudine A. 3-4 , RAKOTOVAO Marcelle 5 , RASOARAHONA Jean R. E. 1 1 College of Agricultural Sciences (Dept Food and Agricultural Industries) and Doctoral School for Engineering of Processes and Industrial, Agricultural and Food Systems, University of Antananarivo. 2 Ambositra Institute of Technology (Dept of Food Process and craft Industries) 3 Plant – Health Laboratory, Fianarantsoa, Madagascar 4 Faculty of Science, University of Fianarantsoa, Madagascar 5 Chemistry and Natural Products Laboratory, Faculty of Science, University of Antananarivo, Madagascar DOI: 10.29322/IJSRP.11.07.2021.p11529 http://dx.doi.org/10.29322/IJSRP.11.07.2021.p11529 Abstract - The aim of this study is to find alternative sources of pectin from three plant wastes mixtures, namely mango (Mangifera indica) fody variety, yellow variety of passion fruit (Passiflora edulis) and creamy brown-striped variety of Bambara groundnut (Vigna subterranea). A Mixture Experiments with Process Variables (MPV) design was applied. It is a combination of Scheffé’s centroid mixture design and a full factorial design of the process variables (pH and Liquid/Solid ratio: LSR). The pH level was set at 1.5 and 2. The LSR level was fixed at 12.5ml/g and 15ml/g. Citric acid was used as acidifying agent. Pectin was extracted in a two-step sequential extraction at 80°C for 60 minutes. The plant sources, the mixing and the joint action of the pH and the LSR had significant effects on the production of high- yielded pectins. All the mixes showed more important yields than individual plant sources at the couple of pH 1.5/LSR 15ml/g. At this condition, an optimum yield of 47.7% can be achieved with the mix composed by 69.7% of mango peel and 30.3% of Bambara groundnut shell. The MPV design is an innovative method permitting the identification of the synergetic or antagonistic effect of mixing and the selection of the suitable extraction conditions favorable to high-yielded extraction. Farther characterization, optimization and classification of these pectins will be needed in order to assess their commercial aptitude. Keywords- pectin, wastes mixtures, MPV design, extraction, yield 1. INTRODUCTION Population growth, industrialization, and urbanization have accelerated the generation of all kinds of wastes, causing serious environmental problems (soil, air and water pollution) [1]. The treatment and consumption of fruits and vegetables, for example, produces solid waste that is sometimes very high. Among many others, three types of waste are considered in this study. The Bambara groundnut (Vigna subterranea) produces 13 to 38% [2]. Mango (Mangifera indica) releases 30-50% of which 15-20% comes from its skin [3]. Passion fruit (Passiflora edulis) discharges 65 to 75% [1, 4]. Madagascar's mango production amounts to 150,000 - 200,000 tons per year [5]. Passion fruit production is around 500 tons [6, 7]. Bambara groundnut is a legume that can improve the bioavailability of phosphorus in ferritic soil. From a nutritional point of view, it is the richest in methionine, and lysine of all vegetables foods, although it has not generated much interest in research and development [8, 9]. National production is estimated at 2,600 tons [10]. Significant quantities of pectin and other high value-added bioproducts (polyphenols, essential oils, enzymes, etc.) can be extracted from the wastes of these plants before recycling them into other products: lignocellulosic materials, organic fertilizers, etc. [11]. Citrus peel and apple pomace are the two major sources of pectin most industrially exploited. But various fruits and vegetables by- products have been identified as potential sources of marketable pectin. Mango peel and passion fruit rinds’ pectins were already studied by several authors. Bambara groundnut shell contains appreciable quantity of fiber (25.19%). Therefore, it may contain a good amount of pectin [12-14]. Pectin is a ubiquitous natural polymer found in the cell membranes of superior plants. Its wide and growing use as a hydrocolloid by the food industry is rapidly increasing [15]. Its traditional use as a gelling, thickening and stabilizing agent is complemented by its emerging use as a fat substitute and functional ingredient in the health sector [16]. It also has a place in beauty products, personal care (paints, toothpaste, and shampoos) and the pharmaceutical sector, including its new use as a nutraceutical ingredient [17]. In 2010, the European Food Safety Authority (EFSA) validated the use of pectin as a dietary supplement in reducing postprandial glucose responses. It is involved in regulating blood cholesterol levels and increasing satiety, leading to a reduction in energy