Publications (2)0 Total impact
Article: Nonthermal starch hydrolysis using ultra high pressure: I. Effects of acids and starch concentrations[show abstract] [hide abstract]
ABSTRACT: Corn starches with 2 mol/l hydrochloric acid (HCl), 2 mol/l sulfuric acid (H2SO4) and 2 mol/l oxalic acid (C2H2O4) were pressurized at 600 MPa for 30 min. Corn starch with C2H2O4 formed a gel after ultra-high-pressure (UHP) treatment. Corn starch with HCl showed partial disintegration but starch with H2SO4 maintained its shape. Corn starch with HCl showed higher (0.42–0.47) degree of hydrolysis compared to starch with C2H2O4 (about 0.14) and H2SO4 (0.13–0.14) regardless of increasing starch concentration up to 20 g/100 g sample. Main component of starch hydrolysate was maltose for HCl and oligosaccharides for H2SO4 and C2H2O4. Crystallinity of starch with HCl decreased with decreasing starch concentration as observed by both differential scanning calorimetry (DSC) and X-ray diffraction. Therefore, UHP can be used for nonthermal starch hydrolysis and HCl would be a good catalyst for UHP starch hydrolysis compared to H2SO4 and C2H2O4. This work provides a potential of nonthermal UHP processing for new starch hydrolysis method.LWT - Food Science and Technology. 39(10):1125-1132.
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ABSTRACT: The effects of puffing process on chemical conversion of ginsenosides, extraction yields and crude saponin contents in red ginseng were investigated. To reach a maximum extraction yield, puffed red ginseng took only 8 h, while non-puffed red ginseng required at least 20 h showing extraction yields of 45.7 g solid extract/100 g sample and 44.5 g solid extract/100 g sample, respectively. Extraction yield increased slightly with increasing puffing pressure. Puffed red ginseng showed higher crude saponin contents (201.0–219.0 mg/g extract) than non-puffed one (161.7–189.0 mg/g extract). As the puffing pressure increased, minor ginsenosides (Rg3, F2, Rk1 and Rg5) increased but the contents of major ginsenosides (Rb1, Rb2, Rc, Rd, Re and Rg1) decreased. These results indicated that a puffing process may provide an effective method to reduce the extraction time, improve the extraction yield and increase the crude saponin content of red ginseng.LWT - Food Science and Technology.