Comparative study on the effects of grain blending on functional compound content and in vitro biological activity.

In this study, changes in bioactive compound contents and the in vitro biological activity of mixed grains, including oats, sorghum, finger millet, adzuki bean, and proso millet, with eight different blending ratios were investigated. The total phenolic compounds and flavonoid contents ranged from 14.43-16.53 mg gallic acid equivalent/g extract and 1.22-5.37 mg catechin equivalent/g extract, respectively, depending on the blending ratio. The DI-8 blend (30% oats, 30% sorghum, 15% finger millet, 15% adzuki bean, and 10% proso millet) exhibited relatively higher antioxidant and anti-diabetic effects than other blending samples. The levels of twelve amino acids and eight organic acids in the grain mixes were measured. Among the twenty metabolites, malonic acid, asparagine, oxalic acid, tartaric acid, and proline were identified as key metabolites across the blending samples. Moreover, the levels of lactic acid, oxalic acid, and malonic acid, which are positively correlated with α-glucosidase inhibition activity, were considerably higher in the DI-blending samples. The results of this study suggest that the DI-8 blend could be used as a functional ingredient as it has several bioactive compounds and biological activities, including anti-diabetic activity.

Genome-wide association study to identify novel loci and genes for Fusarium root rot resistance in sweet potato using genotyping-by-sequencing.

Fusarium root rot, caused by Fusarium solani, is a major post-harvest disease in sweet potatoes (Ipomoea batatas (L.) Lam.). An effective strategy for controlling this disease is the development of resistant varieties. In this study, a genome-wide association study (GWAS) was conducted on 96 sweet potato genotypes to identify novel candidate loci and dissect the genetic basis of Fusarium root rot resistance. Genotyping was performed using genotyping-by-sequencing (GBS), and 44,255 SNPs were identified after filtering. The genotypes (n = 96) were evaluated through resistance tests in 2021 and 2022, separately and combined. The GWAS identified two significant SNP markers (LG3_22903756 and LG4_2449919) on chromosomes 3 and 4 associated with Fusarium root rot resistance, respectively. Lesion length showed significant differences between homozygous A and G alleles of LG3_22903756, which can potentially be used to develop molecular markers for selecting accessions resistant to Fusarium root rot. Expression analysis of 11 putative genes flanking the significant SNPs revealed the alteration in the expression of nine genes, indicating their possible involvement in Fusarium root rot resistance. The results of this study will aid in the marker-assisted selection and functional analysis of candidate genes for Fusarium root rot resistance in sweet potatoes.

Influence of Thermal Processing on Free and Bound Forms of Phenolics and Antioxidant Capacity of Rice Hull (Oryza sativa L.).

The objective of this study was to evaluate the effects of heat treatment on the phenolics and antioxidant activity of rice hull. Heat treatment was performed at temperatures 80∼140°C for 1∼5 h, and the heated rice hull was extracted with 80% (v/v) methanol in an ultrasonic bath. The highest total polyphenol and flavonoid content (10.68 mg gallic acid equivalents/g and 1.83 mg catechin equivalents/g, respectively) occurred in rice hull heated at 130°C for 5 h. During heat treatment, the content of free phenolic acids increased compared with that of the bound phenolic acids. The highest 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and reducing power was observed in rice hull heated at 140°C for 3 h. The highest OH radical scavenging activity was 75.30% in rice hull heated at 140°C for 5 h. These results suggested that heat treatment was an efficient method to enhance the antioxidant characteristics of rice hull.

Physicochemical Characteristics of Starch in Sweet Potato Cultivars Grown in Korea.

The objective of this study was to investigate the structural and physicochemical properties of starch from seven sweet potato cultivars (Shinyulmi, Sinjami, Hogammi, Jeonmi, Jinyulmi, Juhwangmi, and Pungwonmi). Jeonmi and Jinyulmi had amylose contents of 40.04% and 37.39%, respectively, whereas Juhwangmi and Pungwonmihad amylose contents of 30.95% and 32.37%, respectively. As a result of amylopectin polymerization, the seven cultivars were found to have high (>48%) contents of the degree of polymerization (DP) 13∼24 fraction, whereas the DP≥37 fraction content was <3.45%. The level of resistant starch was highest in Jeonmi (>30%) and lowest in Pungwonmi (<5%). The in vitro digestibility of Pungwonmi was greater than that of the other cultivars. Starch X-ray patterns did not differ among the cultivars. The results of this study provide useful information for the food industry regarding the application of sweet potato starches.

Intracellular Reactive Oxygen Species (ROS) Removal and Cytoprotection Effects of Sweet Potatoes of Various Flesh Colors and Their Polyphenols, Including Anthocyanin.

The flesh color of sweet potatoes varies based on the antioxidant pigments in the cultivar. In this study, the antioxidant characteristics of various flesh color sweet potato cultivars (Jinyulmi, Juhwangmi, Pungwonmi, and Sinjami) were investigated. The polyphenol contents were highest in the purple-fleshed cultivar, Sinjami (39, 68, and 71 µg gallic acid equivalent/g in distilled water, fermented ethanol, and ethanol extracts, respectively). The Sinjami cultivar contained 29 mg/100 g of anthocyanin, which is the major component resulting in increased concentrations of polyphenols. Using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid), 2,2-diphenyl-1-picrylhydrazyl, and ferric reducing ability of plasma assays, Sinjami showed greater antioxidant activity than the other cultivars. Additionally, the Sinjami extracts could recover cellular reactive oxygen species levels in tert-butyl hydroperoxide-stimulated HepG2 cells to a normal level. In conclusion, anthocyanin-enriched Sinjami has strong antioxidant activities and could improve health by suppressing oxidative damage.

Phenolic compounds and antioxidant activity in sweet potato after heat treatment.

BACKGROUND: The ability of heat treatment with a soaking solvent to increase soluble phenolic compounds due to the liberation or breakdown of the cell matrix has been investigated in various plants. This study investigated the changes in phenolic compounds and antioxidant activities of 12 sweet potato cultivars after heat treatment with distilled water or prethanol A. RESULTS: The highest total polyphenol content (134.67 mg gallic acid equivalents/g extract residue) and flavonoid content (65.43 mg catechin equivalents/g extract residue) was observed in the 'Jami' (JM) cultivar after heat treatment with prethanol A. Higher polyphenol and flavonoid content was generally observed in the purple sweet potato cultivars. Salicylic acid was the major phenolic acid, followed by protocatechuic acid or chlorogenic acid in almost all untreated sweet potato cultivars. The salicylic acid, vanillic acid, gallic acid, and caffeic acid content of the sweet potatoes increased after the heat treatment, whereas the protocatechuic acid and chlorogenic acid content decreased. The highest 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis(3-ethyl benzothiazoline)-6-sulfonic acid (ABTS) radical scavenging activity levels were observed in the JM cultivar subjected to heat treatment with prethanol A (48.15 and 80.00 mg TE/g extract residue, respectively). CONCLUSION: These results suggest that heat treatment with a soaking solvent is an efficient method to enhance the antioxidant characteristics of Korean sweet potato cultivars. © 2019 Society of Chemical Industry.

Oat germination and ultrafiltration process improves the polyphenol and avenanthramide contents with protective effect in oxidative-damaged HepG2 cells.

Oat is the nutritious crop containing various compounds with antioxidant properties, such as polyphenols. In this study, we investigated the effect of germination and ultrafiltration process on polyphenol and avenanthramide contents in oat as well as their cytoprotective effect. Germination of oat for 48 hr significantly increased avenanthramide (5.5 to 11.3 mg/g) and polyphenol (115 to 155 mg GAE/g) contents. The compounds were more concentrated after ultrafiltration using 10 kDa membranes (polyphenol, 206 GAE/g; avenanthramide, 18 mg/g). In addition, oat extracts significantly reduced the cellular ROS level against tert-butyl hydroperoxide (t-BHP) stimulation in HepG2 cells. In the mechanistic study, oat extracts induced Nrf2 translocation to the nucleus by inhibition of Keap1 expression, resulting into upregulation of γ-GCS and NQO1. In conclusion, oat germination and ultrafiltration processes increased the polyphenol content, including that of avenanthramide. These extracts protected cells from t-BHP by radical scavenging activities and induced Nrf2 pathway activation. PRACTICAL APPLICATIONS: This study presents the method for avenanthramide-concentrated extract which is unique bioactive compounds in oat. In addition, antioxidant activity and their mechanisms of the avenanthramide-enriched extracts were evaluated. The polyphenol compounds including avenanthramide were found to increase after germination and ultrafiltration, thereby improving the radical scavenging ability. These results can be utilized as data for the development of health-promoting materials using oats.

Assessment of microbial safety and quality changes of brown and white cooked rice treated with atmospheric pressure plasma.

The microbial and physicochemical properties of brown and white cooked rice treated by atmospheric pressure plasma (APP). APP was produced (250 W, 15 kHz, ambient air) and applied to brown and white cooked rice for 5, 10, and 20 min. The 20-min plasma treatment reduced in bacterial counts by 2.01 log CFU/g when cooked rice were inoculated with Bacillus cereus or Escherichia coli O157:H7. The pH of the brown cooked rice was decreased by the 5-min plasma. The hardness values of APP-treated brown and white cooked rice were lower than untreated samples. The reducing sugar contents of brown and white cooked rice were significantly higher than those in untreated samples. Lipid oxidation of APP-treated brown and white cooked rice were higher compared to untreated samples. These results indicate that APP improves microbial quality, although further studies should be conducted to change the physicochemical qualities of brown and white cooked rice induced by APP.

Changes in the functional components and radical scavenging activity of maize under various roasting conditions.

The phenolic compounds and radical scavenging activity of ethanolic extracts from maize at various roasting conditions were evaluated in this research. The free sugar contents in roasted maize significantly decreased with higher roasting temperature and longer roasting time. The total polyphenol and total flavonoid contents in roasted maize significantly increased with higher roasting temperature and longer roasting time. The predominant phenolic acid in the roasted maize was homogentisic acid. The contents of homogentisic acid and myricetin in roasted maize significantly increased with higher roasting temperature and longer roasting time. The DPPH and ABTS radical scavenging activities of roasted maize significantly increased with higher roasting temperature and longer roasting time. DPPH and ABTS radical scavenging activities were positively correlated with phenolic compounds. The activities of these components increased following heat treatments because of the low molecularization effects of the heating process, which resulted in active, low-molecular-weight components that were readily extracted.

Effect of sorghum ethyl-acetate extract on benign prostatic hyperplasia induced by testosterone in Sprague-Dawley rats.

Benign prostatic hyperplasia (BPH) is commonly observed in men > 50 years worldwide. Phytotherapy is one of the many treatment options. Sorghum (Sorghum bicolor L.) contains various health-improving phytochemicals with antioxidant and inhibitory activities on cell proliferation, both in vitro and in vivo. To confirm the effects of Donganme sorghum ethyl-acetate extract (DSEE) on BPH, we induced BPH in Spragye-Dawley rats using exogenous testosterone. We measured prostate weight, examined prostrates histopathologically, and analyzed mRNAs associated with male hormones and proteins associated with cell proliferation in the prostate. DSEE inhibited weight gain of the prostate; decreased mRNA expressions of androgen receptor and 5α-reductase II; and improved histopathological symptoms, the protein-expressed ratio of Bax/Bcl-2, and the oxidative status of BPH induced by testosterone in SD rats. Therefore, DSEE may have potential as a preventive or therapeutic agent against BPH.

Starch characteristics of cowpea and mungbean cultivars grown in Korea.

Physicochemical properties of starches from 5 different Korean cultivars of cowpea and mungbean were examined. Starch granules had elliptical to spherical granules. Volume median diameter of granules ranged from 17.0 µm to 48.6 µm, with a significantly larger median granule diameter in cowpea starches than mungbean starches. Apparent amylose content ranged from 35.7% to 38.5%. Among cowpea starches, Seowon had a higher molecular weight and longer amylopectin average chain length than other cultivars. Between mungbean starches, Sohyun had a lower amylose molecular weight but a longer amylopectin average chain length than Dahyun. The relative crystallinity and gelatinization enthalpy of cowpea starches were greater than those of mungbean starches. Okdang had higher peak and final viscosities than other cowpea starches, whereas two mungbean varieties showed similar values for pasting parameters. Seowon in the cowpea starches and Sohyun in mungbean starches had higher gel hardness than other cultivars.

Cooking Characteristics and Antioxidant Activity of Rice-Barley Mix at Different Cooking Method and Mixing Ratio.

This study aimed to compare the phenolic compounds and antioxidant activity of barley at different proportion (0, 5, 10, 15, and 20%), and using different cooking methods. The grains used in this experiment are barley (Hordeum vulgare L. cv. Huinchalssal) and Samkwang rice. The rice-barley mixture was cooked using general and high pressure cooking methods with and without fermented alcohol. The quality characteristics such as water binding capacity, pasting characteristic, water solubility, and swelling power of different proportions of barley were evaluated. The antioxidant characteristics evaluated are total polyphenol, flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azinobis(3-ethylbenothiazoline-6-sulphonic acid) (ABTS) diammonium salt radical scavenging activities. Results showed that peak [195.0~184.0 rapid visco units (RVU)], trough (130.0~116.2 RVU), final (252.0~221.8 RVU), and setback viscosity (57.0~37.5 RVU) decreased correspondingly with the increase in the amount of barley. Water binding capacity (187.31~136.01%) and swelling power (162.37~127.58%) decreased as amounts of barley increases, however the water solubility (5.35~6.89%) increased. Moreover, the total polyphenol and flavonoid, and the DPPH and ABTS radical scavenging activities contents increased as the amounts of barley in the mixture increases. This study generally aims to provide useful information for the manufacturing of processed products.

Comparative Analysis of γ-Oryzanol, ß-Glucan, Total Phenolic Content and Antioxidant Activity in Fermented Rice Bran of Different Varieties.

Rice bran, a by-product derived from processing rice, is a rich source of bioactive compounds. Recent studies have suggested that the fermentation can improve their biological activities. This study aimed to determined the level of γ-oryzanol, ß-glucan and total phenol contents of fermented rice bran from 21 Korean varieties, as well as to evaluate their antioxidant activities. We also assessed the validation of the analytical method for determining γ-oryzanol content in fermented rice brans. Among the fermented rice brans, the Haedam rice bran contained the highest level of total phenol content (156.08 mg gallic acid equivalents/g), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (71.30%) and ORAC (Oxygen radical absorbance capacity) value (1101.31 µM trolox equivalents/g). Furthermore, the fermented Migwang rice bran showed the highest level of γ-oryzanol content (294.77 ± 6.74 mg/100 g).

Antioxidant Contents and Antioxidant Activities of White and Colored Potatoes (Solanum tuberosum L.).

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl- 2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

Physiological Activities of Thiacremonone Produced in High Temperature and High Pressure Treated Garlic.

To examine the possibility of using thiacremonone isolated from high-temperature-high-pressure treated garlic, this study investigated the physiological activities properties. The IC50 values of hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radical scavenging activities of thiacremonone were 92.50, 65.05, 12.60, and 81.53 µg/mL, respectively. On the other hand, the activities of vitamin C were 104.93, 99.43, 42.42, and 122.64 µg/mL, and the activities of butylated hydroxyanisole were 37.22, 68.45, 22.47, and 40.54 µg/mL, respectively. The IC50 value of ACE inhibition activities of thiacremonone and captoprill were 0.265 and 0.036 µg/mL, respectively. The IC50 value of xanthine oxidase inhibition activities of thiacremonone and allopurinol were 39.430 and 9.346 µg/mL, respectively. The IC50 value of tyrosinase inhibition activities of thiacremonone and kojic acid were 101.931 and 65.648 µg/mL, respectively.

Isolation and Identification of an Antiproliferative Compound from Fructose-Tryptophan Maillard Reaction Products.

This study was performed to isolate and identify a compound with antiproliferative activity against human stomach cancer cell lines, from fructose-tryptophan Maillard reaction products (MRPs). The MRPs, prepared from a fructose-tryptophan solution heated at 130 °C for 2 h, were fractionated into five solvent fractions: n-hexane, chloroform, ethyl acetate, butanol, and water. The highest antiproliferative activity was found in the chloroform fraction (85.93% at 200 µg/mL), and the active compound from this chloroform fraction was purified by silica gel column chromatography, TLC, and preparative HPLC. The antiproliferative activity (IC50) of the active compound was 42.24 µg/mL, and the active compound was identified as perlolyrine (C16H10N2O2) by (1)H/(13)C NMR, DEPT, HMBC, and LC-ESI-MS. Therefore, this research may be useful in developing perlolyrine as a functional therapeutic agent.

Isolation of Lignan and Fatty Acid Derivatives from the Grains of Echinochloa utilis and Their Inhibition of Lipopolysaccharide-Induced Nitric Oxide Production in RAW 264.7 Cells.

Two new fatty acid derivatives, echinochlorins A (8) and B (9) and a racemic lignan, (±)-anti-1-(4-hydroxy-3-methoxyphenyl)-2-{4-[(E)-3-acetoxypropen-1-yl]-2-methoxyphenoxy}propan-1,3-diol 3-acetate (1), were isolated from Echinochloa utilis grains, along with six known lignans (2-7) and two fatty acid derivatives (10, 11). Their structures were established by spectroscopic data analyses (IR, UV, HR-FABMS, GC-MS, and 1D and 2D NMR). The configuration of 1 was determined by Mosher's method. Compound 5 displayed potential inhibitory activity on lipopolysaccharide-induced NO production in macrophage RAW 264.7 cells with an IC50 value of 4.8 ± 0.5 µM. These isolated compounds in crude EtOH extract were also quantitated by HPLC.

Functional beverage from fermented soymilk with improved amino nitrogen, ß-glucosidase activity and aglycone content using Bacillus subtilis starter.

The bioactivity of soymilk was enhanced by fermentation with three strains of ß-glucosidaseproducing Bacillus subtilis for 36 h at 37oC. The results indicated that protease, cellulase, and ß-glucosidase activities were significantly (p<0.05) increased with increasing fermentation time. In addition, the amino-type nitrogen content in B. subtilis-fermented soymilk was increased to 121.1-140.7 mg% after 36 h of fermentation. Among the isoflavones in soymilk, the contents of ß-glucosides or acetyl-glucosides were decreased, while aglycone content was increased by fermentation. In particular, the soymilk fermented with B. subtilis HJ18-9 had highest ß-glucosidase activity and the largest increase in aglycone content. The total aerobic and anaerobic cell counts were increased with increasing fermentation time. Therefore, this study suggests that soy beverages fermented with ß-glucosidase-producing B. subtilis have the potential to enhance the health and nutritional status of consumers.

Physicochemical and in vitro binding properties of barley ß-glucan treated with hydrogen peroxide.

This study investigated the changes in content, purity, physical properties, and in vitro binding properties of barley ß-glucan by oxidation treatment. Barleys (Hordeum vulgare) were oxidized, using different concentrations of hydrogen peroxide (0.2-1.0% H2O2). The total and soluble ß-glucan contents ranged from 8.41% and 4.81% in the control to 9.48% and 6.45% in the 0.6% H2O2 treatment. With increasing H2O2 concentration, the purity of ß-glucan increased from 35% to 70%, whereas molecular weight (MW), viscosity, and water-binding capacities decreased to 2.0 × 10(4)Da, 3.9 cP, and 4.45 g water/g ß-glucan, respectively. Oil binding capacities ranged from 8.29 g of oil/g in non-oxidized ß-glucan to 9.42 g of oil/g in ß-glucan oxidized with 0.6% H2O2. The MW, viscosity, and binding capacities of waxy barley ß-glucan were higher than those of non-waxy barley ß-glucan. Oxidation by hydrogen peroxide improved the physical properties and in vitro binding capacity of barley ß-glucan.

Characteristics of the Thermal Degradation of Glucose and Maltose Solutions.

In order to investigate the thermal degradation of glucose and maltose solutions after high temperature and high pressure (HTHP) treatment, the samples were treated at temperatures of 110, 120, 130, 140, and 150°C for 1, 2, 3, 4, and 5 h in an apparatus for HTHP treatment. Glucose and maltose solutions (20% w/w) were prepared by weighing glucose and maltose and adding distilled water in the desired proportion. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugar contents, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) were evaluated. With increasing heating temperatures and times, the L-, a-, and b-values decreased. The pH and free sugar contents decreased, and organic acids and HMF contents increased with greater temperatures and times. EDA (%) and the AEAC of the heating sugars increased with the increases in temperatures and times.