This paper reviews on various approaches and methodologies for understanding contributing factors to food palatability through flavor analysis. A retronasal aroma simulator (RAS) was used for the analysis of the volatiles released in a mouth cavity during mastication. The flavor products of RASAROMA^® series were developed based on RAS analysis to add genuine character to various fruit flavors. A RAS was also utilized as a useful tool to make adjustment of the retronasal aroma profiles, which led to develop flavor products customized for non-calorie drinks that made flavored drinks taste like drinks sweetened with sugar. The effects of milk addition on flavor release were investigated, and a novel procedure has been proposed to predict the relative release of each odorant’s release from milk added drinks to that from water. Some of the contributing factors to food palatability have been revealed by these findings, but full understanding of the palatability is still under way.

Visible-near infrared spectra of 576 “Fuji” apples harvested in 2015 and 2016 were acquired with an apple sorting machine. One month after the spectral acquisition, the cut surface of each samples was scanned, and the occurrence of internal fresh browning was assessed. Various preprocessing methods, including newly proposed brute force differential absorbance, were applied to spectra acquired by the top and bottom spectrometer installed in the sorting machine, and models for the prediction of the occurrence of internal browning were built by partial least squares discriminant analysis. When a “metamodel” was developed by combining models with the lowest error discrimination rate for each of the top and bottom spectrometer, it was possible to predict the occurrence of internal browning with 19.8% classification error, 88.6% sensitivity and 78.1% specificity. In this research, a sorting machine which is installed in actual apple sorting factories was used. Therefore, the results of this research can be easily applied to the apple sorting sites, and it is expected to contribute to the added value improvement of “Fuji” apples.

X-ray diffraction (XRD) was used to analyse potato starch with a 20% moisture content that was made digestion-resistant by the addition of palmitic acid and heat treatment at temperatures in the range of 120-160℃. This starch was also analysed for the quantity of fatty acids able to form starch complexes and in vitro digestion test. Changes in molecular structure that accompany starch-fatty acid complex formation were then investigated based on the results from these analyses. XRD analysis confirmed that fatty acid addition caused emergence of new peaks in the region of 2θ＝13, 19°. There was a strong positive correlation between the 2 new peaks and the internal free fatty acid content, which also increased at higher heat treatment temperatures. This positive correlation suggested these peaks are attributable to structures from the starch-fatty acid complex.