Flavonoids are a group of plant polyphenol secondary metabolites, which widely exist in plant systems. Recently, flavonoids from plant-based sources have been gaining more interest due to their versatile biological activities. The biological activities of flavonoids are dependent upon their chemical structures, which in turn rely on their structural class, level of hydroxylation, substitution pattern, connection position, existence of C2=C3 double bond, and level of polymerization. Flavonoids are considered nutraceuticals in diet. They help prevent many chronic and degenerative illnesses through various biological activities, such as free radical scavenging, anti-lipid peroxidation, and xanthine oxidase inhibition, as well as their anti-inflammatory, antimicrobial, and anti-cancer activities. The goal of the present review is to evaluate flavonoids’ chemical structural features and their biological activities as they relate to preventing chronic diseases affecting human health, and further navigate the relationship between the chemical structure and their biological function.
In this study, the effects of heat-moisture treatment (boiling or steaming for 45 min) prior to hot air drying (70 o C for 8 h) on water activity (Aw), moisture (MC), Brix, color, and texture of dried sweet potato slices were investigated to identify the best pretreatment condition for producing dried sweet potato with the best eating quality. Dried sweet potato slices pretreated by boiling (BL) showed significantly lower Aw, MC, and hardness while Brix was significantly higher than with steaming (ST) treatment. There were no significant differences for the color, springiness, cohesiveness, gumminess, and brittleness indexes. At 8 h drying, the Aw, MC, Brix, and hardness of the BL and ST samples were 0.81 and 0.82, 19.71% and 25.53%, 53.80% and 49.40%, and 20.49 kg/cm 2 and 31.98 kg/ cm 2 , respectively. This information will be useful for manufacturers in the production of dried sweet potato slices. These findings provide evidence of the feasibility of heat-moisture treatments in the production of dried sweet potato.
In this study, Bacillus sp. SRCM 112835 was isolated from soybean paste (Doenjang, Korean Fermented Soy Paste). Bacillus sp. SRCM 112835 showed biosorption of the Cu (II) in aqueous solution. The strain effectively absorbed 30.2% of the Cu (II) from a 52.3 mg/L within 60 min. The properties of the Bacillus sp. SRCM 112835 were investigated by Fourier transform infrared spectroscopy (FT-IR), point of zero charge (pHpzc), and phylogenetic analysis. The influence of initial pH (2.08-9.98) and biomass dosage (0.005-0.07 g) were likewise probed. Isotherm and kinetic experiment results suggested that the Langmuir isotherm and pseudo-second-order kinetic models well-fitted the experimental data, respectively.
The purpose of this study was to investigate the extraction yield and physicochemical characteristics of mucin from the epidermal mucus of Misgurnus mizolepis. Ninety percent ethanol produced the highest yield of mucin. At higher concentrations, mucin had more elastic properties, as revealed by dynamic viscoelasticity measurements. Differential scanning calorimetry (DSC) demonstrated that mucin is a thermostable glycoprotein. Denaturation enthalpy increased as mucin concentration increased. Mucin inhibited the growth of both Escherichia coli and Bacillus cereus, but had better antimicrobial activity in the former. Mucin also exhibited antioxidant activity, equivalent to 66.64% of that of L-cysteine. Mucin inhibited elastase activity and MMP-1 & MMP-2 expression activity, and induced hyaluronic acid expression. It is indicating that mucin is effective in moisturizing and anti-aging the skin. Thus, mucin from the epidermal mucus of Misgurnus mizolepis could have great potential as a non-food material in various industries.
This study evaluated the microbiological quality of fresh-cut bell pepper and ginger, as well as the inactivation effects of intense pulsed light (IPL) on E. coli ATCC 25922 inoculated in the fresh-cut samples by varying the treatment voltages (1,200-2,400 V) and time (1–7 min). The contamination levels of mesophilic bacteria, psychrophilic bacteria, yeast and mold for bell pepper and ginger were 6.64±0.81 and 6.35±1.96 log CFU/g, 6.75±1.13 and 5.63±1.89 log CFU/g, and 4.68±0.43 and 4.57±1.25 log CFU/g respectively. Through the IPL treatment at 2,400 V for 7 min, 2.04 and 2.11 log of E. coli ATCC 25922 inoculated in bell pepper and ginger were reduced, respectively, with a negligible temperature rise (< 2.2oC). Although the reduction rate varied, the bactericidal effect of E. coli ATCC 25922 showed an increase as treatment time and voltage increased. Under the same treatment conditions, temperature increased by 1.71oC and 2.13oC for bell pepper and ginger, respectively. These results demonstrate that IPL is a suitable device for inactivating E. coli ATCC 25922 on fresh-cut bell pepper and ginger.
This study was conducted to investigate the quality of kimchi cabbages stored under a pallet unit-controlled atmosphere (PUCA), containing 2% O2 and 5% CO2, and to develop quality prediction models for cabbages stored under such conditions. Summer and winter cabbage samples were divided into PUCA-exposed groups and atmospheric airexposed control groups (in a cold storage). The control summer cabbages lost up to 8.31% of their weight, whereas the PUCA-exposed summer cabbages lost only 1.23% of their weight. Additionally, PUCA storage effectively delayed the reduction in cabbage moisture content compared with the control storage. After storage for 60 and 120 days of the summer and winter samples, respectively, the reducing sugar contents were higher in the PUCA groups than in the control groups. The linear regression analysis-derived equations for predicting the storage period, weight loss, and moisture content in the control groups, as well as those for predicting the storage period and weight loss in the PUCA groups, were appropriate according to the adjusted coefficient of determination, root mean square error, accuracy factor, and bias factor values. Therefore, this PUCA system would be useful for improving the shelf life of the postharvest summer and winter cabbages used in the commercial kimchi industry.
After making kimchi by adding 0, 0.5, 1.0, 1.5% aronia (Aronia melanocarpa), microbiological and sensory characteristics were measured while fermenting it at 10oC for 28 d. The numbers of total cell and lactic acid bacteria were decreased after the maximum levels of microbial counts; that is, day 3 for control and 0.5% treatment and day 14 for 1.0, 1.5, and 2.0% treatments. Coliforms were not detected after 7 d in control and 0.5% treatments; however, they were detected after 14 d i-n 1.5 and 2.0% treatments throughout the fermentation period. Sensory properties were evaluated in the aspects of both acceptability and intensity characteristics. In the preference characteristics, overall acceptability was highest in the 1.0% group after preparation and after 14 d of fermentation. As for the aronia-added group, the intensity of the hot taste of Nabak Kimchi decreased while that of its sweet taste and sour taste increased according to the rise of both the amount of the added aronia to the kimchi and fermentation period. In conclusion, the addition of 1.0% aronia can be used to produce high-quality Nabak Kimchi while extending its storage period.
This study was conducted to find out the change in nutritional components and antioxidant activities of salted Chinese cabbage according to storage temperature and duration using supercooling. Salted Chinese cabbage was investigated every 2 weeks while it was stored at -2℃ and 2℃ for 8 weeks. This was followed by an analysis of freeze dried samples. The analyzed contents were free sugar and free amino acid contents, DPPH and ABTS radical scavenging activity, and TPC and TFC. Free sugar content of salted Chinese cabbage decreased with longer storage duration, while free amino acid did not change significantly. DPPH and ABTS radical scavenging activities did not change significantly with storage duration whereas the TPC and TFC of salted Chinese cabbage stored at -2℃ was higher than that stored at 2℃ for 6 weeks. Therefore, the quality of salted Chinese cabbage was maintained in direct refrigerator storage for a long duration, showing economic and industrial values as a new storage technology.
This study was conducted to investigate changes on the quality characteristics of Prunus davidiana sugar extracts (PSEs) by processing conditions. The PSEs were prepared by extraction with commercial sucrose at 4°C or 25°C for 9 months with or without a pressure plate. The quality characteristics of PSEs were analyzed for Bxo, pH, total acidity, Hunter color value, alcohol content, polyphenol content, DPPH radical scaveging activity, and free sugar content. Bxo increased significantly while pH decreased with increased storage period (p<0.05). The PSEs stored at 4oC scored lower than those stored at 25oC for total acidity, alcohol content, and polyphenol contents. The PSEs with pressure plate possessed lower alcohol content and higher polyphenol content and DPPH free radical scavenging activity than those without pressure plate. The sucrose content in PSEs decreased with increased storage period, while glucose and fructose contents increased. These results indicate that by increasing storage period, sucrose in PSEs is decomposed into glucose and fructose, and the quality characteristics of PSEs such as total acidity, alcohol, and polyphenol content depend on processing conditions.