title: Microwave-assisted alkaline extraction of galactan-rich rhamnogalacturonan I from potato cell wall by-product.
abstract: Galactan-rich rhamnogalacturonan I (RG I), exhibiting promising health benefits, is the most abundant polysaccharide in potato pulp by-product. In the present study, the microwave-assisted alkaline extraction of galactan-rich RG I was investigated. Solid/liquid ratio was identified as the most significant parameter affecting linearly yield and galactose/rhamnose contents. Microwave power and solid/liquid ratio exhibited a significant adverse interactive effect on the yield. Galactose content of extracted polysaccharides can be modulated by compromising between KOH concentration and extraction time, which exhibited adverse interaction. Optimum conditions were identified using the established predicted models and consisted of treatment of potato cell wall at solid/liquid ratio of 2.9% (w/v) with 1.5M KOH under microwave power of 36.0 W for 2.0 min. Yield of intact galactan-rich RG I of 21.6% and productivity of 192.0 g/Lh were achieved. The functional properties of RG I-rich polysaccharides were comparable or superior to potato galactan and oranges homogalacturonan.
authors.affiliation: Department of Food Science and Agricultural Chemistry, McGill University, H9X 3V9 Quebec, QC, Canada.
authors.forename: Nastaran
authors.initials: N
authors.lastname: Khodaei
authors.affiliation: Department of Food Science and Agricultural Chemistry, McGill University, H9X 3V9 Quebec, QC, Canada. Electronic address: salwa.karboune@mcgill.ca.
authors.forename: Salwa
authors.initials: S
authors.lastname: Karboune
authors.affiliation: Department of Bioresource Engineering, McGill University, H9X 3V9 Quebec, QC, Canada.
authors.forename: Valérie
authors.initials: V
authors.lastname: Orsat
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D005685:Galactans / Q000032:analysis*; D006801:Humans; D008872:Microwaves; D008970:Molecular Weight; D010368:Pectins / Q000032:analysis / Q000302:isolation & purification*; D011134:Polysaccharides / Q000032:analysis; D011198:Solanum tuberosum / Q000737:chemistry*; D012995:Solubility
chemical_list: D005685:Galactans; D011134:Polysaccharides; C042491:rhamnogalacturonan I; D010368:Pectins
keywords: Functional properties; Galactan-rich rhamnogalacturonan I; Microwave extraction; Pectic polysaccharides; Potato