Blue light is reported to be harmful to eyes by inducing reactive oxygen species (ROS). Herein, the roles of Peucedanum japonicum Thunb. leaf extract (PJE) in corneal wound healing under blue light irradiation are investigated. Blue-light-irradiated human corneal epithelial cells (HCECs) show increased intracellular ROS levels and delayed wound healing without a change in survival, and these effects are reversed by PJE treatment. In acute toxicity tests, a single oral administration of PJE (5000 mg/kg) does not induce any signs of clinical toxicity or body weight changes for 15 days post-administration. Rats with OD (oculus dexter, right eye) corneal wounds are divided into seven treatment groups: NL (nonwounded OS (oculus sinister, left eye)), NR (wounded OD), BL (wounded OD + blue light (BL)), and PJE (BL + 25, 50, 100, 200 mg/kg). Blue-light-induced delayed wound healing is dose-dependently recovered by orally administering PJE once daily starting 5 days before wound generation. The reduced tear volume in both eyes in the BL group is also restored by PJE. Forty-eight hours after wound generation, the numbers of inflammatory and apoptotic cells and the expression levels of interleukin-6 (IL-6) largely increase in the BL group, but these values return to almost normal after PJE treatment. The key components of PJE, identified by high-performance liquid chromatography (HPLC) fractionation, are CA, neochlorogenic acid (NCA), and cryptochlorogenic acid (CCA). Each CA isomer effectively reverses the delayed wound healing and excessive ROS production, and their mixture synergistically enhances these effects. The expression of messenger RNAs (mRNAs) related to ROS, such as SOD1, CAT, GPX1, GSTM1, GSTP1, HO-1, and TRXR1, is significantly upregulated by PJE, its components, and the component mixture. Therefore, PJE protects against blue-light-induced delayed corneal wound healing via its antioxidative, anti-inflammatory, and antiapoptotic effects mechanistically related to ROS production.

Seon-Ah Son, Eun Seong Shin, Yoo Min Park, Ayeong Ma, Hyelin Yang, ShinHye Kim, and Tai-Sun Shin. Journal of the Korean Society of Food Science and Nutrition 2022;51:71-81. https://doi.org/10.3746/jkfn.2022.51.1.71

In this study, we focused on reducing the molecular weight of purified red okra pectin using various hydrolytic enzymes and evaluating its physicochemical properties or characterization. The enzyme treatments targeted both the main pectin chain and the side-chain sugars, resulting in a reduction in the molecular weight by approximately 10% (from 647 kDa) to 60% (down to 252 kDa). Both the purified red okra pectin and enzyme-treated pectins exhibited a homogalacturonan (HG)-type backbone. Fourier transform infrared (FT-IR) spectroscopy revealed a decrease in the absorbance peak for the pectin backbone (1200–1000 cm⁻¹) in the low-molecular-weight (LMW) pectin. The most significant decrease was observed at 3300 cm⁻¹ in pectin treated with both RGH+RGAE enzymes, indicating reduced sugar bonds. These results demonstrate the physicochemical changes in LMW red okra pectin following enzyme treatment and confirm its potential applications due to its unique characteristics.

Recently, many studies have reported the properties and functionality of okra pectin. However, these studies are about green okra pods, and pectin in red okra pods, stems, and roots has not been reported. Therefore, this study aimed to optimize the red okra extraction method using response surface methodology (RSM) analysis and evaluate the effects of extraction time, temperature, solvent ratio, and pH on the extract yield and crude pectin content. Based on RSM analysis, 4.35 h, 98.04 °C, 23.34 solvent ratio, and pH 3.36 are the optimal parameters for extracting crude pectin from red okra, and the crude pectin content was predicted to be 40.83%. When red okra was extracted under these extraction conditions (4 h, 100 °C, 23 solvent ratio, and pH 3), the extraction yield was 45.26%, and the crude pectin content was 38.42%, which was similar to the yield obtained under the conditions derived from the RSM analysis. In addition, the pH control using hydrochloric acid was replaced with citric acid, and the changes in extract yield and crude pectin content were compared. When citric acid was used, the extract yield was 49.15% (8.6% increase), and the crude pectin content was 42.76 ± 2.56% (11.3% increase); compared to when hydrochloric acid was used, the yield increased. Finally, the standardization of red okra raw materials was determined by analyzing the extraction yield and crude pectin content by part, harvest time, and size of red okra using the established extraction method using citric acid. As a result, it was confirmed that the extraction yield obtained from the established extraction method was reached from the extraction of red okra fruits up to 12 cm in size that were harvested between July and November. Additionally, compared to the non-pectin fraction, the crude pectin fraction isolated from red okra pod extract showed significantly higher total phenolic content (TPC) and total flavonoid content (TFC). These findings, reported for the first time, may contribute to the development of processes to purify red okra pectin, functional evaluation studies of pectin, and potential applications of red okra extract in various industries and research.

서 론 최근 30여 년간 우리나라의 1인당 쌀 소비량은 연간 120 kg 수준에서 2023년 기준 56.5 kg까지 급감하였다(MAFRA, 2024). 이와 같은 소비 행태 변화는 전통적인 '밥' 중심 식생 활이 간편식 및 밀 기반 식사로 전환된 데 기인하며, 이에 따라 쌀 산업은 주곡 생산 중심에서 벗어나 글루텐프리 (gluten-free) 및 기능성 식품 소재로의 패러다임 전환이 요구되고 있다. 이러한 배경 속에서 단백질 함량이 15% 이 상인 고단백 쌀가루가 개발되었으며, 타피오카나 vital glu-ten과 같은 보조 첨가물과의 소량 배합을 통해 제빵 적성을 확보할 수 있음이 보고된 바 있다(Paz 등, 2021). 특히 고단 백 쌀가루를 활용한 모닝빵은 부드러운 조직감, 높은 소화 율,