Intake of Koji Amazake Improves Defecation Frequency in Healthy Adults

Development of fermented Atemoya (Annona cherimola × Annona squamosa)-Amazake increased intestinal next-generation probiotics

Akkermansia muciniphila and Faecalibacterium prausnitzii are next-generation probiotics, which has been reported to protect disease and effectively utilize various carbohydrates (starch and pectin) as nutrients for growth. Atemoya exhibiting fruity flavor, which is suitable for enhancing aroma and attenuating unpleasant taste caused by the koji metabolites. Results indicated that malic acid was increased (from 42.4 to 70.1 mg/100 g) in fermented Atemoya-Amazake. In addition, fermented Atemoya-Amazake elevated growthes in A. muciniphila and F. prausnitzii. Similarly, the populations of Parabacteroides (5.7 fold) and Akkermansia (1.66 fold) were elevated by fermented Atemoya-Amazake treatment in an in vitro simulated gastrointestinal system compared to the control group. Results revealed that fermented Atemoya-Amazake modulated the intestinal microbiota through increasing the production of short-chain fatty acids (exhibiting anti-pathogenic activity) for 2.1, 2.5, 2.6, and 2.1 folds in acetic acid, propionic acid, isobutyric acid, and butyric acid, respectively; suggesting this fermented Atemoya-Amazake could be applied in intestinal protection.

Preventive Roles of Rice-koji Extracts and Ergothioneine on Anxiety- and Pain-like Responses under Psychophysical Stress Conditions in Male Mice

This study determined the effect of daily administration of Rice-koji on anxiety and nociception in mice subjected to repeated forced swim stress (FST). In a parallel experiment, it was determined whether ergothioneine (EGT) contained in Rice-koji displayed similar effects. Anxiety and nociception were assessed behaviorally using multiple procedures. c-Fos and FosB immunoreactivities were quantified to assess the effect of both treatments on neural responses in the paraventricular nucleus of the hypothalamus (PVN), nucleus raphe magnus (NRM), and lumbar spinal dorsal horn (DH). FST increased anxiety- and pain-like behaviors in the hindpaw. Rice-koji or EGT significantly prevented these behaviors after FST. In the absence of formalin, both treatments prevented decreased FosB expressions in the PVN after FST, while no effect was seen in the NRM and DH. In the presence of formalin, both treatments prevented changes in c-Fos and FosB expressions in all areas in FST mice. Further, in vitro experiments using SH-SY5Y cells were conducted. Rice-koji and EGT did not affect cell viability but changed the level of brain-derived neurotrophic factor. In conclusion, Rice-koji could reduce anxiety and pain associated with psychophysical stress, possibly mediated by the modulatory effects of EGT on neural functions in the brain.

Improving γ-Oryzanol and γ-Aminobutyric Acid Contents in Rice Beverage Amazake Produced with Brown, Milled and Germinated Rices

Rice is an important source of γ-oryzanol (GO) and γ-aminobutyric acid (GABA), which are bioactive compounds that may benefit blood lipid and pressure control. Both GO and GABA can be improved by germination and fermentation. Fermentation with A. oryzae produces Koji, a rice-based starter for Amazake, a naturally sweet beverage. Germinated rice (brown and milled rice), were tested to improve those bioactive compounds during the fermentation process. The resulting Koji was optimised to GO and GABA through a response surface methodology; α-amylase activity and starch content were also assessed. The different rice matrix resulting from the germination largely impacted the biosynthesis of GABA, α-amylase and starch contents. Amazake, obtained by germinated rice, has increased GO and GABA contents when compared to the one obtained from milled rice (from a non-detectable value to 27.65 ± 0.23 mg/100 g for GO and from 163.95 ± 24.7 to 271.53 ± 5.7 mg/100 g for GABA). A panel of 136 Portuguese consumers tasted the beverage in a blind overall tasting test followed by an informed test, using 9-point scales. The consumer scores had a mean value of 4.67 ± 1.9 and 4.9 ± 1.8, meaning that cultural differences may play an important role with regard to liking and accepting Amazake.

Koji amazake Maintains Water Content in the Left Cheek Skin of Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Comparative Trial

Purpose

Improvement in water content and skin barrier function on human skin is believed to be induced by koji amazake, a non-alcoholic beverage derived from rice fermented by Aspergillus oryzae (A. oryzae). In order to scientifically identify the effects of koji amazake on human skin, we performed a randomized, double-blind, placebo-controlled, parallel-group comparative trial and quantified the content of glucosylceramide (GlcCer) which would be responsible for the effects.

Participants and Methods

Healthy adults concerned with their skin dryness were divided into koji amazake (N = 30) or placebo group (N = 30). During this test, the test beverages were ingested at 118 g/day. Their water content and trans-epidermal water loss (TEWL) were measured at 0 week (baseline) and 8 weeks. The content of GlcCer in test beverages was quantified by HPLC-ELSD.

Results

In comparison with the placebo group, the water content in the left cheek of individuals in the koji amazake group was maintained for 8 weeks. In addition, changes in water content from the baseline to 8 weeks differed significantly between the koji amazake (0.19) and placebo groups (-3.98). Unexpectedly, there was no significant difference in the TEWL between koji amazake and placebo group. We analyzed GlcCer in both koji amazake and placebo beverages, which were found to contain 1.35 ± 0.11 and 0.30 ± 0.07 mg/118 g, respectively. The amount of GlcCer in koji amazake was approximately equal to the dosage of plant-derived GlcCer which has the ability to improve water content and TEWL in humans.

Conclusion

Present study has shown that intake of koji amazake contributes to maintain the water content only on the left cheek. The content of GlcCer derived from koji amazake was adequate for maintenance of the water content compared to previous reports. Therefore, it was concluded that GlcCer in koji amazake acts as a functional ingredient.