Suna Kim

Oat bars are commonly consumed cereal-based products, and their quality and safety are strongly affected by the formulation and processing conditions. In particular, the type of syrup used as sweetener can influence quality-related attributes, Maillard reaction products (MRPs), antioxidant activity, and acrylamide formation. In addition, the use of different cooking methods may further modify these characteristics. Therefore, this study investigated the effects of syrup type—honey (H), allulose (AL), and fructo-oligosaccharide syrup (FOS)—and cooking method (oven cooking and air frying) on the quality characteristics and acrylamide content of oat bars. Oat bars prepared with AL showed significantly reduced lightness, yellowness, and hardness compared with those prepared using H and FOS. However, AL oat bars also exhibited higher MRP levels, radical scavenging activity, and total polyphenol content, suggesting enhanced antioxidant properties. Markedly higher acrylamide levels were observed in AL oat bars, reaching 1,339.74 ± 10.08 ppb after oven cooking and 1,152.05 ± 1.31 ppb after air frying. In comparison, oat bars prepared with H and FOS showed substantially lower acrylamide concentrations, regardless of the cooking method. The syrup type was found to be a more determining factor than the cooking method in determining the acrylamide levels and overall quality attributes of oat bars. Consequently, choosing an appropriate sweetening agent is essential for enhancing the safety and quality characteristics of oat-based snacks.

This study analyzes the flavonoid, carotenoid, and organic acid profiles of 18 commercial dried citrus chips, including 6 Korean and 12 imported cultivars, which are categorized into citron, pomelo, and mandarin groups based on their origin. Hesperidin and narirutin predominate in citron and mandarin groups, whereas naringin is prevalent in pomelo group. Green tangerine chip showed the highest contents of hesperidin (3180.24 ± 296.55 mg/100 g) and narirutin (424.98 ± 9.23 mg/100 g), while grapefruit chip had the highest naringin content (1916.66 ± 89.66 mg/100 g). β-cryptoxanthin was detected in the citron and mandarin groups, with tangerine chip containing the highest amount (18.35 ± 0.99 μg/g). The citron group exhibited higher organic acid concentrations than pomelo and other mandarin groups. The highest and lowest ascorbic acid contents were found in grapefruit chip and kumquat chip, at 2973.56 ± 56.78 and 111.84 ± 2.17 mg/100 g, respectively.

This study investigated the effects of storage temperature on the functional quality of kimchi during short- and long-term fermentation. Pretreated napa cabbage (NC) quality was analyzed, and kimchi was prepared using pretreated NC and stored at either 4 °C or 15 °C until reaching optimal and excessive fermentation stages. Fermented kimchi samples were analyzed for pH, lactic acid bacteria (LAB) counts, total polyphenol content (TPC), DPPH and ABTS radical scavenging activities, and glucosinolates and their breakdown products. Fermentation at 15 °C progressed rapidly, reaching the optimal pH range (4.0–4.5) within 3 days, and resulted in significantly higher LAB counts and TPC compared to samples stored at 4 °C (p < 0.05). In contrast, prolonged storage at 4 °C led to a decrease in both TPC, radical scavenging activities, and LAB counts during the excessive fermentation stage. Glucosinolates were progressively degraded overtime; however, their breakdown product, ascorbigen, increased under short-term fermentation at 15 °C than during prolonged storage at 4 °C. These results suggest that short-term fermentation at 15 °C is more effective than long-term fermentation at 4 °C in enhancing the functional quality of kimchi by promoting LAB growth and preserving bioactive compounds.

This study aimed to optimize the accelerated solvent extraction (ASE) condition of zeaxanthin from orange paprika using a response surface methodology (RSM) or an artificial neural network (ANN) with a genetic algorithm (GA). Input variables were ethanol concentration, extraction time, and extraction temperature, while output variable was zeaxanthin. The mean squared error and regression correlation coefficient of the developed ANN model were 0.3038 and 0.9983, respectively. Predicted optimal extraction conditions from ANN-GA for maximum zeaxanthin were 100% ethanol, 3.4 min, and 99.2 °C. The relative errors under the optimal extraction conditions were RSM for 10.46% and ANN-GA for 2.18%. We showed that the recovery of hydrophobic zeaxanthin could be performed using ethanol, an eco-friendly solvent, via ASE, and the extraction efficiency could be improved by ANN-GA modeling than RSM. Therefore, combining ASE and ANN-GA might be desirable for the efficient and eco-friendly extraction of hydrophobic functional materials from food resources.

Although most lemons are imported into Korea, their consumption is increasing. Development of domestic varieties of Jeramon and Minimon is currently underway in an effort to meet the increasing demand for fresh lemons. In this study, an analysis of the physicochemical characteristics of Jeramon and Minimon, including their flavor components and antioxidant properties, was conducted. The results revealed that these new varieties of Korean lemon can be regarded as good sources of antioxidants and phytochemicals. Compared to Sunkist, the most consumed lemon variety in Korea, Minimon contained more than twice as much β-cryptoxanthin, and the content of L-ascorbic acid was more than three-four-fold higher in both Minimon and Jeramon. In addition, results from measurement of DPPH and ABTS radical scavenging activities indicated that Jeramon extract exhibited the highest antioxidant activity. In the volatile profile analysis, the profiles of volatile components showed high similarity among the three lemon samples, and the composition ratio was largely dominated by terpenoids. A markedly higher ratio of d-limonene and thymol was detected in the Minimon variety compared with that in the other two varieties. Collectively, the findings from this study on Korean lemon varieties provide a basis as well as valuable guidance for breeding domestic lemon varieties.

The objective of this study was to determine reactive oxygen species (ROS) produced by fagopyrin F-rich fraction (FFF) separated from Tartary buckwheat flower extract exposed to lights and to investigate its antibacterial photodynamic inactivation (PDI) against Streptococcus mutans and its biofilm. ROS producing mechanisms involving FFF with light exposure were determined using a spectrophotometer and a fluorometer. S. mutans and its biofilm inactivation after PDI treatment of FFF using blue light (BL; 450 nm) were determined by plate count method and crystal violet assay, respectively. The biofilm destruction by ROS produced from FFF after exposure to BL was visualized using confocal laser scanning microscopy (CLSM) and field emission scanning electron microscope (FE-SEM). BL among 3 light sources produced type 1 ROS the most when applying FFF as a photosensitizer. FFF exposed to BL (5 and 10 J/cm²) significantly more inhibited S. mutans viability and biofilm formation than FFF without the light exposure (p < 0.05). In the PDI of FFF exposed to BL (10 J/cm²), an apparent destruction of S. mutans and its biofilm were observed by the CLSM and FE-SEM. Antibacterial PDI effect of FFF was determined for the first time in this study.

Kang HJ, et al. Nutr Res Pract. 2021 Jun;15(3):346-354. https://doi.org/10.4162/nrp.2021.15.3.346