Naganori Ohisa

Heat Treatments of Milled Rice and Properties of the Flours

ABSTRACT The effects of autoclave and oven treatments on the gelatinization of rice flour and on the rheological characteristics of its pastes were studied by differential scanning calorimetry (DSC), rapid viscoanalysis (RVA), and rotational viscometry. Flours from autoclave-treated rice (ATR) and oven-treated rice (OTR) were prepared, respectively, by heating at 120°C for 60 min and 160°C for 60 min followed by drying (ATR sample), and grinding at 2.2–12.9% moisture content. The rice flour dispersions were adjusted between pH 6.3 and 2.8 using 0.2M citrate buffer. The retort processing of rice flour in water pastes were done at 120°C for 20 min either once or twice. The gelatinization peak temperature (PT and To) and the peak temperature corresponding to the amylose-lipid complexes (Tp3) of ATR increased at pH 6.3 and 2.8 compared with OTR and UTR flour. This indicates that the internal structures of the starch granules in ATR became more stable to heat and acid, even though the damaged starch content of...

Application of a portable near infrared spectrometer for the manufacturing of noodle products

We applied the rapid, non-destructive and convenient near infrared (NIR) spectroscopy method, using a portable NIR spectrometer, to the manufacturing process of noodle products (Inaniwa Udon). Characterisation of wheat flours, which are a primary ingredient of noodle products, was identified easily by the pricipal component (PC) score plots based on the standardised NIR spectra. We assessed these results not only from a practical standpoint, but also for the chemical interpretation of NIR spectra. Without any sample preparation, NIR spectra revealed moisture content in the products. Further investigation revealed that moisture content is proportional to viable bacterial counts in the products, so determining moisture content in products by the rapid, non-destructive and convenient method of using a portable NIR spectrometer, as used in this work, is extremely useful in the Inaniwa Udon quality control process.