The objective of this study was to evaluate the effects of cereal flour with high amylopectin short chain ratio on staling of bread. The wheat variety “Minaminoyawara” and the waxy rice variety “Aichimochi 126” have an amylopectin with a high ratio of short chains, and the starch is reported to exhibit slow retrogradation. Bread staling is influenced by both the amylose content and the structure of amylopectin in starch. In this study, two blend flours with the same amylose content were prepared by blending “Minaminoyawara” and “Aichimochi 126” with commercial flour. Bread staling was kinetically analyzed by measuring the crumb hardness and the re-gelatinization enthalpy of starch retrogradation in crumb. The results showed that bread made with blend flours containing the mutant starch was softer than the control bread using only commercial flour under all storage conditions. The re-gelatinization enthalpy of starch retrogradation in crumb was also smaller than that in the control bread. In the kinetic analysis, the staling ratio constant of crumb (SRC) and the retrogradation ratio of starch in crumb (RRC) values were low in the bread containing the mutant starch. These results indicate that amylopectin, which has a high proportion of short chains, inhibits staling of bread. The two cereal flours used in this study may help extend the shelf life of bakery products.
This study aimed to clarify the physical characteristics and aroma releases of spice pastes prepared using micro wet stone-milling. Coriander seeds were wet milled with water, and the effects of milling loops and the solid to water ratio on particle size and phase separation were investigated. The increase in milling loops and solid ratio decreased the phase separation and improved the stability of the paste. Fluorescence microscopic imaging of the paste showed that oil droplets were dispersed in the water phase, suggesting that the oil contained in the seeds had been released through the milling process. To clarify the aroma release from the coriander seed paste during heating, the amounts of β-linalool and camphor released into the headspace were quantified. This was compared to the aroma release from the mixture of dry ground coriander powder and water. The release of aroma components from the paste was lower than that of the powder-water mixture, and comparison between different pastes suggested that the more stable the paste, the lower the release of aroma components. These results indicate that the dispersion stability of solids and oil droplets in spice pastes may affect the release behavior of aroma components.
Previously, we have found that the use of visible and near-infrared (VIS-NIR) spectroscopy is a useful non-destructive method for quantification of β-cryptoxanthin in Satsuma mandarin as an alternative method to HPLC. In this study, we examined whether the use of VIS-NIR spectroscopy would permit the quantification of β-cryptoxanthin in mid-late ripening citrus cultivars. Examination of the associations between VIS-NIR spectra data and β-cryptoxanthin contents was performed using partial least squares regression (PLSR). We found that the absorption in the region of 600 nm is particularly important for estimating the β-cryptoxanthin content, and that the wavelength regions related to sugar content also affect the assessment of β-cryptoxanthin. From these results, it is suggested that the use of VIS-NIR spectroscopy could allow prediction of β-cryptoxanthin content in mid-late ripening citrus cultivars.