Current Topics in Food and Biodynamic Chemistry Research

Studies on chemical structures, metabolisms and physiological significances of food and bioactive natural products are currently being addressed in our laboratory to explain their health effects in humans. Some novel molecules and functions of food and nutrients were discovered, and new foodstuffs and products were developed. The researches were carried out on stable authentic phosphatidylcholine hydroperoxide; membrane lipid glycation and its inhibitors; cancer growth suppression by conjugated triene fatty acids; antiangiogenicity of rice bran tocotrienol; glucosidase inhibition by mulberry 1-deoxynojirimycin; and high quality broccoli products regarding hepatoprotective sulforaphane contents

高トコトリエノール米の作出と機能性食材への応用に関する研究

Tohoku University宮澤 陽

Comparative Studies on the Hepatoprotective Effect of White and Coloured Rice Bran Oil against Acetaminophen-Induced Oxidative Stress in Mice through Antioxidant- and Xenobiotic-Metabolizing Systems

Rice bran oil (RBO) comprises various nutrients and phytochemicals which exhibit several health benefits. There are no studies regarding the functional effects of different colours of RBO. This study was aimed to compare the constituents and antioxidant activities of white rice bran oil (WRBO) and coloured rice bran oil (CRBO). Each RBO showed similar free fatty acid profiles. However, greater amounts of vitamin E, phytosterols, carotenoids, and chlorophylls were found in CRBO, which had lower γ-oryzanol content than WRBO. Oxidative stress was induced in male mice by an overdose of acetaminophen (APAP) at 300 mg/kg body weight. The mice were then fed with RBO at the equivalent dose to 100 mg/kg body weight of γ-oryzanol three hours later and sacrificed six hours after APAP treatment. The administration of 100 mg γ-oryzanol equivalent in CRBO ameliorated APAP-induced hepatotoxicity in mice more strongly than 100 mg γ-oryzanol equivalent in WRBO, as evidenced by the significant reduction of serum ALT, hepatocellular necrosis, and hepatic lipid peroxidation. CRBO could improve xenobiotic-metabolizing and antioxidant enzyme activities, including glutathione S-transferase, superoxide dismutase, glutathione peroxidase, and glutathione reductase, and also increase mRNA expression of various antioxidant-responsive genes. Vitamin E, phytosterols, carotenoids, and chlorophyll might be the protective compounds in CRBO that alleviate APAP-induced hepatotoxicity through the interruption of APAP metabolism and the activation of antioxidant systems at both transcriptional and enzymatic levels. These findings might provide a protective role of CRBO on oxidative stress associated with several degenerative diseases

Evaluation of the Optimum Harvesting Maturity of Makhwaen Fruit for the Perfumery Industry

Harvesting makhwaen (Zanthoxylum myriacanthum Wall. ex Hook. f) fruits at the appropriate maturity is the key to ensure that the essential oil quality meets the need of consumers. In common practice, the fruits are usually harvested when their pericarps start to open and fruits are greenish-red in colour depending on the judgment of the farmers. This leads to inconsistencies in the essential oil quality. This research aims at characterising the aromatic profiles of makhwaen essential oil thereby for consumers to choose the quality that best fits their need and eventually identify the optimum harvesting index of the fruits. The effects of maturity states viz. 15, 36, 45 and 60 (MK15-60) days after fruiting on chemical and sensorial quality of the essential oil was evaluated. Fruit sizes ranged from ~3.3–3.7 mm and fruits appeared to dry initially when they reached 45 days. Essential oils were extracted from these fruits after they had been oven dried (60 °C) to the same moisture content, about 10%. The chemical profiles of the essential oil were different. L-limonene and sabinene were evaluated as key components for good quality essential oil and they were found to be higher in MK45 and MK60 (max = 139.04 µg·mL−1 and max = 146.27 respectively). NIR spectral patterns of pure extracted oil for every different harvesting time (of every different harvesting time of MK60 and MK36) were similar. Sensorial descriptive analysis by semi-trained panellists defined six terms for characteristics (woody, citrus, herb, sweet, pine and spice). The panels provided the highest rating score (15 numeric scale) of citrus and pine scents at MK45, while sweet and woody aromas were the highest at MK15. The spice scent was maximum when the fruits were harvested at 36 days after fruiting. From this study we suggest that the optimum harvesting index for the distinctive aroma of essential oil ought to be at late harvesting (45–60 days after fruiting). The findings contribute to our understanding of the harvesting maturity, which can also provide significant benefit for the perfumery industry, i.e., the optimum harvesting stage that imparts the essential oil with highest quality