title: Effects of NaCl and soaking temperature on the phenolic compounds, α-tocopherol, γ-oryzanol and fatty acids of glutinous rice.
abstract: Soaking is one of the important steps of the parboiling process. In this study, we investigated the effect of changes in different sodium chloride (NaCl) content (0%, 1.5% and 3.0% NaCl, w/v) of soaking media and soaking temperatures (30°C, 45°C and 60°C) on the phenolic compounds (α-tocopherol, γ-oryzanol) and on the fatty acids of glutinous rice, compared with unsoaked samples. Overall, the total phenolic content, total phenolic acids, γ-oryzanol, saturated fatty acid and mono-unsaturated fatty acid of the glutinous rice showed an increasing trend as NaCl content and soaking temperature increased, while α-tocopherol and polyunsaturated fatty acids decreased. Soaking at 3.0% NaCl provided the highest total phenolic content, total phenolic acids and γ-oryzanol (0.2mg GAE/g, 63.61 μg/g and 139.76 mg/100g, respectively) for the soaking treatments tested. Nevertheless, the amount of α-tocopherol and polyunsaturated fatty acid were found to be the highest (18.30/100g and 39.74%, respectively) in unsoaked rice.
authors.affiliation: Research Unit of Process and Product Development of Functional Foods, Department of Food Technology and Nutrition, Faculty of Technology, Mahasarakham University, Mahasarakham 44100, Thailand.
authors.forename: Pornpisanu
authors.initials: P
authors.lastname: Thammapat
authors.affiliation: Research Unit of Drying Technology for Agricultural Products, Faculty of Engineering, Mahasarakham University, Mahasarakham 44150, Thailand.
authors.forename: Naret
authors.initials: N
authors.lastname: Meeso
authors.affiliation: Research Unit of Process and Product Development of Functional Foods, Department of Food Technology and Nutrition, Faculty of Technology, Mahasarakham University, Mahasarakham 44100, Thailand. Electronic address: sirithons@hotmail.com.
authors.forename: Sirithon
authors.initials: S
authors.lastname: Siriamornpun
mesh_terms: D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D005511:Food Handling; D061353:Food Storage; D012275:Oryza / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D010666:Phenylpropionates / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D013696:Temperature; D024502:alpha-Tocopherol / Q000737:chemistry*
chemical_list: D005231:Fatty Acids, Unsaturated; D010636:Phenols; D010666:Phenylpropionates; D012965:Sodium Chloride; D024502:alpha-Tocopherol; C013172:gamma-oryzanol
keywords: Bioactive substances; Polyunsaturated fatty acid; Salt; Temperature