title: Effect of citric acid concentration and hydrolysis time on physicochemical properties of sweet potato starches.
abstract: Physicochemical properties of citric acid treated sweet potato starches were investigated in the present study. Sweet potato starch was hydrolyzed using citric acid with different concentrations (1 and 5%) and time periods (1 and 11 h) at 45 °C and was denoted as citric acid treated starch (CTS1 to CTS4) based on their experimental conditions. The recovery yield of acid treated starches was above 85%. The CTS4 sample displayed the highest amylose (around 31%) and water holding capacity its melting temperature was 47.66 °C. The digestibility rate was slightly increased for 78.58% for the CTS3 and CTS4. The gel strength of acid modified starches ranged from 0.27 kg to 1.11 kg. RVA results of acid thinned starches confirmed a low viscosity profile. CTS3 starch illustrated lower enthalpy compared to all other modified starches. All starch samples exhibited a shear-thinning behavior. SEM analysis revealed that the extent of visible degradation was increased at higher hydrolysis time and acid concentration. The CTS3 satisfied the criteria required for starch to act as a fat mimetic. Overall results conveyed that the citric acid treatment of sweet potato starch with 5% acid concentration and 11h period was an ideal condition for the preparation of a fat replacer.
authors.affiliation: Department of Food Science and Nutrition, School of Professional Studies, Periyar University, Salem 636011, Tamil Nadu, India.
authors.forename: Ayenampudi
authors.initials: A
authors.lastname: Surendra Babu
authors.affiliation: Department of Food Science and Nutrition, School of Professional Studies, Periyar University, Salem 636011, Tamil Nadu, India. Electronic address: parimalavalli.dr@gmail.com.
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Parimalavalli
authors.affiliation: Department of Food Science and Post Harvest Technology, Indian Agriculture Research Institute, New Delhi 110012, India.
authors.forename: Shalini Gaur
authors.initials: SG
authors.lastname: Rudra
mesh_terms: D055598:Chemical Phenomena; D019343:Citric Acid / Q000737:chemistry*; D004041:Dietary Fats; D004043:Dietary Fiber; D004655:Emulsions; D006868:Hydrolysis; D027723:Ipomoea batatas / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry; D012212:Rheology; D013213:Starch / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D004041:Dietary Fats; D004043:Dietary Fiber; D004655:Emulsions; D010936:Plant Extracts; D010940:Plant Proteins; D019343:Citric Acid; D013213:Starch
keywords: DSC; Fat replacer; SEM; Sweet potato starch; XRD