Characterization of Japanese Polished Rice by Stable Hydrogen Isotope Analysis of Total Fatty Acids for Tracing Regional Origin

Abstract

We determined the δD values of the total fatty acids of Japanese rice to test the hypothesis that there is a wide variation in the hydrogen isotopic composition (δD) of the total fatty acids of Japanese rice sourced from different growth areas in Japan and to distinguish the minor differences among these growth areas. The δD values showed a wide variation ranging from -216 (Hokkaido) to -183 (Okinawa), indicating a good correlation with the corresponding variations for ambient water (r = 0.63) and mean temperature (r = 0.84). These results suggest that the δD values for the total fatty acids can be representative of the growth environments in Japan.

Preliminary detection method for added rice- and sugarcane-derived brewer’s alcohol in bulk samples of sake by measurement of hydrogen, oxygen, and carbon isotopes

“…On the other hand, the δD and δ 18 O of brewer's alcohol may differ from the native alcohol of unadulterated sake. Because the δD and δ 18 O of organic plant matter are responsive to the isotopic values of the water in the area in which it is grown, 18,19) brewer's alcohol derived from plant carbohydrates has the potential to directly reflect isotopic changes in the plant's origin. Thus, a difference in the δD and δ 18 O in a plant's origin could be useful for detecting brewer's alcohol in sake.…”

“…Further complicating matters, Baudler et al 20) reported that the isotopic values of the distillate were different between the first and last fractions in a distillation process for concentrating and purifying ethanol. While there are a number of studies using δD or δ 18 O to analyze ethanol in alcoholic beverages via gas chromatography-high-temperature conversion-isotope ratio mass spectrometry (GC-TC-IRMS) using the headspace solid-phase microextraction method, the separation of ethanol is relatively complicated and time consuming. 13,21) Measurement via analysis of δD and δ 18 O in bulk alcoholic beverages may have the advantage of quickly screening for alcohol addition without separation of the ethanol (i.e., even in the presence of water and H/O-containing non-volatile components such as sugars).…”

“…While there are a number of studies using δD or δ 18 O to analyze ethanol in alcoholic beverages via gas chromatography-high-temperature conversion-isotope ratio mass spectrometry (GC-TC-IRMS) using the headspace solid-phase microextraction method, the separation of ethanol is relatively complicated and time consuming. 13,21) Measurement via analysis of δD and δ 18 O in bulk alcoholic beverages may have the advantage of quickly screening for alcohol addition without separation of the ethanol (i.e., even in the presence of water and H/O-containing non-volatile components such as sugars). In this study, the possibility of detecting C 3 plant-and C 4 plant-derived brewer's alcohol added to sake by measurement of carbon, hydrogen, and oxygen stable isotopes is examined in bulk samples of lab-brewed sake.…”

“…where R sample is the isotope ratio (i.e., D/H, 18 O/ 16 O, and 13 C/ 12 C) of the sample, and R standard is the isotope ratio of the international standard (Vienna Peedee Belemnite for carbon and Vienna Standard Mean Ocean Water for hydrogen and oxygen). The isotope measurements of δD, δ 18 O, and δ 13 C had standard deviation (SD) of <3.0, <0.4, and <0.2‰, respectively.…”

“…The isotope measurements of δD, δ 18 O, and δ 13 C had standard deviation (SD) of <3.0, <0.4, and <0.2‰, respectively.…”