The number of patients with diabetes mellitus is increasing at an alarming rate and this situation has triggered the interest of searching natural product as an alternative treatment. Stingless bee honey containing a diverse array of bioactive compounds is commonly utilized as a functional food and also found to possess various therapeutic effects including anti-diabetic through α-amylase and α-glucosidase inhibition. However, the composition level of bioactive compounds varying of geographical origins and botanical sources of honey leads to different enzyme inhibition abilities. Therefore, this study explored the total phenolic, total flavonoid, α-amylase and α-glucosidase inhibition activities of stingless bee honey from various botanical origins. In this study, stingless bee honey was collected from 6 different botanical origins namely, acacia, coconut, mangrove, starfruit, multifruit and multiflower plant. Honey from tualang tree was used as a positive control. Phenolic and flavonoid contents as well as α-amylase and α-glucosidase inhibition activities of honey were studied spectrophotometrically. Stingless bee honey from mangrove was found to have the highest phenolic content (141.74±0.03 mg GAE/100 g). The honey collected from coconut origin showed the highest flavonoid content with the value of 51.33±0.02 mg RE/100 g and also achieved the highest percentage inhibition against α-glucosidase (68.33% at 100 µg/mL). Furthermore, tualang honey and honey samples from mangrove, coconut and Acacia tree were found to have strong α-amylase inhibition abilities as their inhibition percentages were more than 70.00% at 100 µg/mL. This study showed that the presence of flavonoid and phenolic compounds in honey from different botanical origins yielded different degree of α-amylase and α-glucosidase inhibition and also recommended the uses of stingless bee honey in diabetes treatment.

This study aimed to assess the incidence and distribution of toxigenic fungi in Korean oat. Toxigenic fungi were isolated from oat samples collected from 12 oat fields from heading to harvest in 2017 and 2018. A total of 745 fungal colonies were isolated based on morphology and identified using marker genes. About 92% of the fungal isolates were Fusarium spp. and others were Penicillium (5.9%) and Aspergillus (2.1%). Fusarium isolates comprised mostly of F. asiaticum (83.1%), followed by F. incarnatum (5.4%), F. proliferatum (3.5%), F. fujikuroi (2.8%), F. tricinctum species complex (FTSC) 11 (1.5%) and F. graminearum (1.0%). About 97% of F. asiaticum was nivalenol type, and 3-acetyl deoxynivalenol (3.2%) and 15-acetyl deoxynivalenol (0.4%) types also were found. Pathogenicity test of the selected Fusarium isolates revealed that F. asiaticum isolates have a wide range of virulence depending on the tested plants. F. graminearum and FTSC 11 isolates from blighted spikelets were the most virulent in naked oat. All Fusarium isolates (n=18) except one (FTSC 11) produced nivalenol (0.2-7.6 μg/g), deoxynivalenol (0.03-6.1 μg/g), and zearalenone (0.1-27.0 μg/g) on rice medium. This study is first report that F. asiaticum causes Fusarium head blight disease of oat in Korea. These findings demonstrate the dominance of F. asiaticum in oat agroecosystems as in rice, wheat and barley in Korea.

The objective of this study is to investigate the quality characteristics of Yanggaeng by using the functional properties of Glechoma hederacea (GH). Sample was dried at 50℃ dry oven. The results of the study were as follows : The Phenolic compounds of GH was 12.99±0.3 mg/g in water extract (GHWE), 3.14±0.07 mg/g in 70% ethanol extract (GHEE). The antioxidant activity of GH was determined in various phenolic concentrations at 50-200 μg/mL. DPPH activities of GHWE and GHEE were 77.16-78.24% and 73.04-77.00%, respectively. The ABTS were 84.35-99.75% and 83.74-99.55%. The anti-oxidant protection factor (PF) were 1.54-1.62 PF and 1.62-2.09 PF and TBARS were 42.93-94.09% and 91.05-95.19%, respectively. Tyrosinase inhibitory activity of GHEE increased concentration dependently. Hyaluronidase inhibition activity of GHEE and GHWE, showing that there were increasing pattern depending on the increases in the phenolics concentration of GH. In texture, Hardness and springiness were significantly different in the control and 2% groups, but cohesiveness and chewiness did not show any significant difference. In color, L value decreased in proportion to concentration, and a and b values did not change. Sensory characteristics showed that the 1% group had the highest score and the 2% group had the lowest score. Thus, when the GHP Yanggaeng was prepared, in consideration of its sensory characteristics, and at appropriate concentration on below 1%.

A total of 1,159 Fusarium strains were isolated from sorghum grown in Danyang and Youngwol in 2017 and 2018. The isolates were analyzed to reveal genetic, toxigenic and pathogenic characteristics. Phylogenetic analysis using TEF-1α and RPB2 genes showed that the samples were contaminated with at least 17 Fusarium species. Among them, F. graminearum, F. proliferatum, F. thapsinum, F. incarnatum, and F. asiaticum were dominant species. In F. graminearum and F. asiaticum, F. graminearum-15-acetyl deoxynivalenol chemotype and F. asiaticum-nivalenol chemotype were frequent. Six Fusarium species tested produced one or more mycotoxins, except F. thapsinum and FTSC 11. F. proliferatum and F. fujikuroi had FUM1 gene (76.0% and 81.6%, respectively) and some isolates produced high level of fumonisin (over 1,000 µg/g). F. proliferatum and F. thapsinum were more virulent than other species on sorghum. These results indicate that Fusarium species in sorghum might produce multiple mycotoxins.

In this study, we investigated the occurrence of mycotoxigenic fungi and mycotoxins in stored peanuts. Two types of peanuts, with and without shell, were stored for 12 and 6 months, respectively and the kernels from each type of peanut were collected and analyzed bimonthly. The stored peanuts were mainly contaminated with Aspergillus, Penicillium, and Fusarium species along with at least 26 other genera. Fungal frequency increased exponentially to reach 79.1±20.3% at 12 months of storage for peanuts with shell, whereas it increased sharply to 100% at 2 months for peanuts without shell. A. pseudoglaucus, A. chevalieri, and P. citrinum were prevalent in peanuts with shell, whereas A. flavus, P. crustosum, and P. polonicum were the most dominant species in peanuts without shell. Mycotoxin analysis revealed that ochratoxin A was detected in only one sample without shell (37.31 μg/kg), while aflatoxins were not detected. Fungal isolates known for mycotoxin production were confirmed to be producing various levels of mycotoxins in potato dextrose agar medium. Among the tested isolates (n=129), 59 (45.7%) produced aflatoxins (0.82-1,213.60 μg/kg), ochratoxin A (39.35-237.20 μg/kg), patulin (1.21-803.76 mg/kg), or fumonisins (0.27-13.70 mg/kg). To our knowledge, this is the first report on mycotoxin production by A. westerdijkiae, A. niger, A. welwitschiae, A. tubingensis, and P. expansum isolates from Korean peanuts. Overall, these results demonstrate the potential risk of not only aflatoxin and ochratoxin A but also patulin and fumonisin contamination in stored peanuts.