title: Enhanced fermentable sugar production from kitchen waste using various pretreatments.
abstract: The kitchen waste fraction in municipal solid waste contains high organic matter particularly carbohydrate that can contribute to fermentable sugar production for subsequent conversion to bioethanol. This study was carried out to evaluate the influence of single and combination pretreatments of kitchen waste by liquid hot water, mild acid pretreatment of hydrochloric acid (HCl) and sulphuric acid (H2SO4) and enzymatic hydrolysis (glucoamylase). The maximum total fermentable sugar produced after combination pretreatment by 1.5% HCl and glucoamylase consisted of 93.25 g/L glucose, 0.542 g/L sucrose, 0.348 g/L maltose, and 0.321 g/L fructose. The glucose released by the combination pretreatment method was 0.79 g glucose/g KW equivalent to 79% of glucose conversion. The effects of the pre-treatment on kitchen waste indicated that the highest solubilization was 40% by the combination method of 1.5% HCl and glucoamylase. The best combination pre-treatment gave concentrations of lactic acid, acetic acid, and propionic acid of 11.74 g/L, 6.77 g/L, and 1.02 g/L, respectively. The decrease of aliphatic absorbance bands of polysaccharides at 2851 and 2923 cm(-1) and the increase on structures of carbonyl absorbance bands at 1600 cm(-1) reflects the progress of the kitchen waste hydrolysis to fermentable sugars. Overall, 1.5% HCl and glucoamylase treatment was the most profitable process as the minimum selling price of glucose was USD 0.101/g kitchen waste. Therefore, the combination pretreatment method was proposed to enhance the production of fermentable sugar, particularly glucose from kitchen waste as the feedstock for bioethanol production.
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Electronic address: hs_hafid@yahoo.com.
authors.forename: Halimatun Saadiah
authors.initials: HS
authors.lastname: Hafid
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Bioprocessing and Biomanufacturing Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Electronic address: nor_aini@upm.edu.my.
authors.forename: Nor'Aini Abdul
authors.initials: NA
authors.lastname: Rahman
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Bioprocessing and Biomanufacturing Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Electronic address: umikalsom@upm.edu.my.
authors.forename: Umi Kalsom
authors.initials: UK
authors.lastname: Md Shah
authors.affiliation: Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Electronic address: azharis@upm.edu.my.
authors.forename: Azhari Samsu
authors.initials: AS
authors.lastname: Baharudin
mesh_terms: D019342:Acetic Acid; D001709:Biotechnology / Q000379:methods; D002241:Carbohydrates / Q000096:biosynthesis*; D004187:Disaccharides / Q000302:isolation & purification*; D005285:Fermentation; D005087:Glucan 1,4-alpha-Glucosidase; D006601:Hexoses / Q000302:isolation & purification*; D006358:Hot Temperature; D006851:Hydrochloric Acid / Q000737:chemistry; D006868:Hydrolysis; D012037:Refuse Disposal / Q000379:methods*; D013464:Sulfuric Acids / Q000737:chemistry; D014866:Waste Products / Q000032:analysis
chemical_list: D002241:Carbohydrates; D004187:Disaccharides; D006601:Hexoses; D013464:Sulfuric Acids; D014866:Waste Products; D005087:Glucan 1,4-alpha-Glucosidase; C033158:sulfuric acid; D019342:Acetic Acid; D006851:Hydrochloric Acid
keywords: Enzymatic hydrolysis; Fermentable sugar; Glucose; Kitchen waste; Pretreatment