title: Effects of soaking and acidification on physicochemical properties of calcium-fortified rice.
abstract: BACKGROUND
  Calcium-fortified rice was prepared by soaking milled rice in calcium lactate solution, steaming and drying, and physicochemical properties were determined to evaluate effects of calcium concentration (0, 30, 50 g L(-1) ), soaking temperature (ambient temperature, 40 °C, 60 °C) and acidification.
  
  
  RESULTS
  Calcium-fortified rice had less lightness. More total solid loss was observed, especially at high soaking temperature. Harder texture was detected with increased calcium concentration. Calcium fortification lowered pasting viscosity of milled rice. Panelists accepted all fortified rice; however, only rice soaked at 50 g L(-1) concentration could be claimed as a good source of calcium. Increasing of soaking temperature induced more penetration of calcium to rice kernels but calcium was lost more easily after washing. With addition of acetic acid to the soaking solution, enriched calcium content was comparable to that of high soaking temperature but with better retention after washing and calcium solubility was improved. Acid induced reduction of lightness and cooked rice hardness but increased total solid loss and pasting viscosity. Although the taste of acetic acid remained, panelists still accepted the fortified rice.
  
  
  CONCLUSIONS
  Calcium-fortified rice (190.47-194.3 mg 100 g(-1) ) could be successfully produced by soaking milled rice in 50 g L(-1) calcium lactate solution at 40 °C or at ambient temperature with acidification. © 2015 Society of Chemical Industry.
authors.affiliation: Division of Food Science and Nutrition, Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, Wattana, Bangkok, Thailand.
authors.forename: Porntip
authors.initials: P
authors.lastname: Sirisoontaralak
authors.affiliation: Faculty of Science, Srinakharinwirot University, Wattana, Bangkok, Thailand.
authors.forename: Pailin
authors.initials: P
authors.lastname: Limboon
authors.affiliation: Faculty of Science, Srinakharinwirot University, Wattana, Bangkok, Thailand.
authors.forename: Sujitra
authors.initials: S
authors.lastname: Jatuwong
authors.affiliation: Division of Food Science and Nutrition, Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, Wattana, Bangkok, Thailand.
authors.forename: Arusa
authors.initials: A
authors.lastname: Chavanalikit
mesh_terms: D002118:Calcium / Q000737:chemistry*; D003296:Cooking; D005527:Food, Fortified; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000737:chemistry*; D014867:Water
chemical_list: D014867:Water; D002118:Calcium
keywords: acid; calcium fortification; retention; rice; soaking