Rice, the seed of Oryza species, is the major cereal crop in most of the developing countries. Nearly 95% of global rice production is done in Asian countries, and about half of the world's population consumes it. Some speciality rices are not commonly consumed. Colored rice is one of such variety. In these varieties, high amounts of anthocyanin pigment are deposited in the rice coat to form its black (also known as purple), brown and red colors. Minimum studies are there to explain the properties of these rice varieties of Thailand. Thus, the current study was aimed to assess the physicochemical and antioxidative properties of three rice varieties (Chiang Mai Black rice, Mali Red rice and Suphanburi-1 Brown rice) of different cultivars of northern Thailand. Rice bran extracts of these three cultivars were prepared with different solvents (polar and non-polar) for the evaluation of total phytochemical content and anti-oxidant free-radical-scavenging properties. Chiang Mai Black rice contained higher concentration of phenolic acid, flavonoids, and anthocyanins (Cyanidin 3-glucoside, peonidin 3-glucoside, cyanidin chloride). Chiang Mai Black rice is richer in free-radical-scavenging compounds and activities than the other tested varieties. Polar extractions of rice bran are high in anti-oxidative compounds and activities than non-polar extractions.Keywords: anti-oxidant; phytochemicals; colored rice variety; polar and non-polar extraction.Practical Application: Nutrient rich rice cultivar has been identified for further characterization of bioactive compounds of rice.

Beta-glucan (BG) is a conserved cell wall components of bacteria, fungi, and yeast. BG is an immunomodulator and stimulates the host immune system. This study was performed to screen Saccharomyces cerevisiae strain with high BG, extraction of BG using different chemical extraction methods, composition analysis of BG, and evaluation of the immunomodulatory effect of high-quality BG using mice model. Ten yeast strains were screened for high BG content using total glucan extraction kit and were subjected to FT-IR analysis. The kit based extraction revealed that HII31 showed a high content of total glucan and BG. HII31 cells were subjected to four different acid/base extractions, which indicated that combination of a strong base (NaDH) and weak acid (CH 3 CDDH) extraction recovered high BG and a high ratio of polysaccharide, protein, and lipid. Further, the immunomodulatory effect of the selected BG was evaluated using mice, which suggested that low dose of HII31-BG induces the expression of selected pro-inflammatory (IL-17, IFN-γ) and anti-inflammatory cytokine (IL-10) significantly, whereas relatively high dose was required to alter the IL-6 and TGF-β expression. Dverall, the present study revealed that BG extracted from HII31 cells alters the expression of studied cytokines, which can be used as a potent immunomodulator in pharmaceutical products.Keywords: beta-glucan; Saccharomyces cerevisiae; immunomodulation; FTIR; cytokines.Practical Application: Identification of optimum extraction procedure for β-glucan (BG) from S. cerevisiae HII31 and revealed that BG can be used as a potent immune modulator in pharmaceutical products.

The current study was employed to assess the influence of the different extraction methods on total tocols, γ-oryzanol content, and antioxidant properties of Chiang Mai Black rice, Mali Red rice, and Suphanburi-1 Brown rice bran oil. Rice bran oil (RBD) was extracted by Hexane, Hot pressed, Cold pressed, and Supercritical Fluid Extraction (SFe) methods. High yield of RBD was extracted by hexane and SFe methods. Total and subgroups of tocols, and γ-oryzanol content were determined by HPLC. The hexane extracted sample accounts for high content of γ-oryzanol and tocols. Besides, all of RBD extracts contain a significantly high amount of γ-tocotrienol. In vitro antioxidant assay results indicated that superior quality of oil was recovered by hexane extraction. The temperature in the extraction process also affects the value of the oil. Superior quality of oil was recovered by hexane extraction, in terms of phytochemical contents and antioxidant properties compared to other tested extraction methods. Further, thorough study of factors compromising the quality and quantity of RBD recovery is required for the development of enhanced functional foods and other related products.Keywords: rice bran oil; tocols; γ-oryzanol; antioxidants.Practical Application: Influence of different extraction methods for the recovery of the principal compounds from RBD has been demonstrated.

Objective: Anthocyanins are the water-soluble pigments most commonly present in flowers, fruits, and vegetables. Anthocyanins have been reported for is antioxidant, anti-inflammatory, antibacterial properties and other health benefits in human. This study was performed to extract and determine the anthocyanin and to access the antioxidant properties of the most commonly used fruits, vegetables and flowers in Thailand.Methods: Extraction of anthocyanin and its aglycones from the selected samples and determination of anthocyanin and anthocyanidins using reversed-phase HPLC analysis. Determination of total antioxidant ability using ABTS, DPPH and FRAP assay.Results: Maximum distribution of tested anthocyanin and anthocyanidin contents was observed in the extracts of Jambolan plum, Ceylon Spinach, Purple Sweet Potato, Purple Lettuce followed by common plum and Red dragon fruit. The extracts of Ma-Kiang, Purple Eggplant, Red Grape, and Purple Lettuce showed the maximum amount of cyanidin 3-glucoside, delphinidin 3-glucoside, peonidin 3-glucoside, and malvidin 3-glucoside, respectively. Likewise, the maximum concentration of cyanidin, delphinidin, peonidin, and malvidin were found in Common plum, Red Khae, Red Cabbage, and Purple Lettuce, respectively. Ma-Kiang extract exhibited the maximum antioxidant activity followed by Red Cabbage, Common Plum, and Purple Eggplant extract compared to the other extracts.Conclusion: The present study, primarily profiled the anthocyanin content of selected fruits, vegetables, and flowers. Among the tested samples, Ma-Kiang extract showed the high cyanidin 3-glucoside content and antioxidant activity. Further, detailed study on the content of anthocyanins at different climate and geographical conditions and other factors are necessary to develop nutraceutical or cosmetic product with a functional ingredient.Keywords: Anthocyanin, Anthocyanidin, Antioxidant activity.

Background: Diabetes mellitus (DM), particularly type 2 DM (T2DM), is one of the most common metabolic disorder worldwide. The prevention measures and treatment strategies for DM are improving steadily. The current study explains the impact of germination on phytochemical content of Thai black rice (BR), and the influence of germinated BR extract (GBRE) supplementation on diabetic conditions in rats. Methods: BR was germinated and the phenolic, anthocyanin, and γ-aminobutyric acid (GABA) content of the extract were analyzed using HPLC and spectrophotometric methods. Streptozotocin-induced diabetic rats were supplemented with high and low doses of GBRE. The plasma glucose, insulin, cholesterol, triglyceride levels, antioxidant status, and antioxidant enzyme levels of treated animals were assessed using ELISA and spectrophotometric methods. Results: Germination enhanced the GABA content of BR, and GBRE intervention improved the total antioxidant capacity and antioxidant enzymes levels in diabetic rats. The plasma glucose, cholesterol, triglyceride levels, insulin resistance and glucose tolerance were reduced, and the degree of insulin secretion in rat plasma was significantly increased upon GBRE treatment. Both pre and post-treatment approaches showed the anti-diabetic ability of GBRE. In most of the analyzed parameters, GBRE was quite equal to the performance of drug-metformin. Conclusions: GBRE supplementation helps prevent and manage the consequences of DM.

The present study estimated the optimum germination conditions to achieve high content of Gamma-amino butyric acid (GABA) and other phytochemicals in Thai black rice cultivar Kum Payao (BR). The Box-Behnken design of response surface methodology was employed to optimize the germination conditions. The changes in the GABA, phytochemical content, impact of salt, and temperature stress variation on phytochemical content, and stability of GABA were studied. The results showed that 12 h of soaking at pH 7, followed by 36 h of germination was the optimum condition to achieve maximum GABA content (0.2029 mg/g of germinated BR (GBR)). The temperature (8 and 30 °C), and salt (50-200 mM NaCl) content affected the phytochemicals of GBR, especially GABA, and anthocyanins. Dbviously, the antioxidant capability, and enzyme (α-amylase and α-glucosidase) inhibiting nature of BR was significantly (P < 0.001) increased after germination. The storage of GBR at 4 °C significantly, preserved the GABA content (∼80%) for 45 days. Primarily, the current study revealed the changes in phytochemical content, and bioactivity of Thai black rice cr. Kum Payao during germination. More studies should be carried out on pharmacological benefits of GABA-rich GBR.Keywords: germinated rice; gamma-amino butyric acid; antioxidant; stress; stability.Practical Application: Dptimization of germination conditions to produce GABA-rich germinated rice for pharmaceutical applications.

Studies on phytochemical properties and bioactivities of rice bran revealed the wealth of natural complex antioxidant compounds. The composition and the properties of the rice bran get altered after fermentation by several microbes. This study was designed to optimize the black rice bran fermentation conditions for the total anthocyanin (ACN) content, total antioxidant properties, and relative activity of β-glucosidase (BGS) by Saccharomyces cerevisiae. The Box–Behnken design and response surface methodology was employed to achieve the maximum response in fermentation. The kinetic analysis of HPLC based phytochemical determination and bioconversion of ACN, and in vitro antioxidant assays were performed during fermentation. The optimum pH, temperature and NaCl concentration to achieve maximum ACN content, antioxidant capacity, and BGS activity were pH 4.0, 40 °C, and 0.5%, respectively. Bioconversion of cyanidin-3-glucoside and peonidin-3-glucoside to cyanidin and peonidin was recorded at a significant level, respectively. The maximum activity of BGS on rice bran was noticed at 24 h of fermentation. The results suggested that phytochemical content was not changed significantly, whereas the antioxidant properties of rice bran were slightly enhanced after 24 h of fermentation. Additional detailed in vivo evaluation is required to explain the impact of submerged fermentation on the bioactivity of rice bran.Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-017-0411-4) contains supplementary material, which is available to authorized users.

Perilla frutescens (Nga-Mon) is an annual herbaceous plant, reported for its antioxidant, anti-allergic, antiinflammatory and neuroprotective properties. The current study was conducted to compare the different pretreatment techniques followed by hexane extraction for perilla seed oil and its pharmaceutical values. There are no significant differences in the yield of seed oil after pre-treatments except sonication. All the pre-treatments diminish the endogenous lipase activity, peroxidation and degradation of the oil. Fatty acid content analysis revealed that the nutrient quality, with respect to fatty acid content, of perilla seed was not compromised with any of the pre-treatments of current study. The results of α-amylase, α-glucosidase and protein glycation inhibition assays suggested that tested perilla seed oils are pharmaceutical candidate for the treatment of carbohydrate related diseases, especially for diabetes. Selection of appropriate pre-treatment strategies will helps to extract the perilla seed oil without any compromise in its quality. The current study suggested that moist heat with pressure can be an appropriate pre-treatment method for perilla seed oil extraction.