title: Physicochemical and Mechanical Properties of Bambara Groundnut Starch Films Modified with Stearic Acid.
abstract: The physicochemical and mechanical properties of biofilm prepared from bambara starch modified with varying concentrations of stearic acid (0%, 2.5%, 3.5%, 5%, 7%, and 10%) were studied. By scanning electron microscopy, bambara starch films modified with stearic acid (≥3.5%) showed a progressively rough surface compared to those with 2.5% stearic acid and the control. Fourier transform infrared spectroscopy spectra revealed a peak shift of approximately 31 cm-1, suggesting the promotion of hydrogen bond formation between hydroxyl groups of starch and stearic acid. The addition of 2.5% stearic acid to bambara starch film reduced water vapor permeability by approximately 17%. Bambara starch films modified with higher concentration of stearic acid were more opaque and showed significantly high melting temperatures. However, mechanical properties of starch films were generally negatively affected by stearic acid. Bambara starch film may be modified with 2.5% stearic acid for improved water vapor permeability and thermal stability with minimal effect on tensile strength.
authors.affiliation: Dept. of Biotechnology and Food Technology, Durban Univ. of Technology, KwaZulu-Natal, Durban, South Africa.
authors.forename: Samson A
authors.initials: SA
authors.lastname: Oyeyinka
authors.affiliation: Dept. of Biotechnology and Food Technology, Durban Univ. of Technology, KwaZulu-Natal, Durban, South Africa.
authors.forename: Suren
authors.initials: S
authors.lastname: Singh
authors.affiliation: Dept. of Biotechnology and Food Technology, Durban Univ. of Technology, KwaZulu-Natal, Durban, South Africa.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Amonsou
mesh_terms: D007887:Fabaceae / Q000737:chemistry*; D018857:Food Packaging / Q000379:methods*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010539:Permeability; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D013229:Stearic Acids; D013696:Temperature; D013718:Tensile Strength; D014867:Water
chemical_list: D013229:Stearic Acids; D014867:Water; C031183:stearic acid; D013213:Starch
keywords: bambara starch; edible films; mechanical; physicochemical; stearic acid