We investigated the effects of cooking (steaming and microwaving) and processing (freeze-drying and hot-air-drying) methods on the antioxidant activity of broccoli florets. 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•), and alkyl^• free radical scavenging assays were employed to assess anti-oxidant potentials. The cytoprotective effect against oxidative damage induced by H₂O₂ was studied using hepatocellular carcinoma (HepG2) cells. Anti-proliferative effects were assessed in MCF-7 and MDA-MB-231 breast cancer cells. L-sulforaphane in broccoli extracts was quantified using high-performance liquid chromatography (HPLC). Steam and microwave treatments caused increases in total polyphenol content (TPC), whereas the total flavonoid content (TFC) decreased following steam treatment. A slight increase in TFC was observed in the microwaved samples. Extracts of all broccoli samples showed almost identical radical scavenging and cytoprotective effects. HPLC demonstrated that steamed (3 min)-freeze-dried (F-S3) and microwaved (2 min)-freeze-dried (F-M2) samples exhibited elevated levels of L-sulforaphane. In addition, the F-S3 and F-M2 extracts displayed strong anti-proliferative effects in MCF-7 cells, which correlated with L-sulforaphane content. As we observed no significant decrease in the antioxidant activity of broccoli florets, the cooking and processing methods and conditions studied here are recommended for broccoli.

Duri Kim, Jung-Hyun Nam, Ji-Yong Hyun, Chang-Sook Kim, and Ji-Yeon Chun. Journal of the Korean Society of Food Science and Nutrition 2022;51:463-75. https://doi.org/10.3746/jkfn.2022.51.5.463

Kwan Woo Jeon · Min Gun Kim · Su Hyeong Heo · Kyung Hwan Boo · Jae-Hoon Kim · Chang Sook Kim. JABC 2022;65:413-9. https://doi.org/10.3839/jabc.2022.053

Ji-Hyun Im, Jung-Hyun Nam, A-Ra Ko, Hee-Jung Jin, Duri Kim, Chang-Sook Kim, and Ji-Yeon Chun. Journal of the Korean Society of Food Science and Nutrition 2022;51:600-10. https://doi.org/10.3746/jkfn.2022.51.6.600

Red beetroots, rich in betanin, may act as prebiotics and impact gut microbiota. Because the human gut microbiota is unique to each person, the effectiveness of prebiotics varies with the enterotype. In this study, we hypothesized that the effects of red beetroot powder (RP) and betanin pigment (BP) would differ depending on the enterotype. Fecal samples from 30 subjects were analyzed and categorized into three enterotypes: Phocaeicola, Prevotella, and Bifidobacterium. Feces were collected from one representative subject from each enterotype cluster for fermentation. Results showed that RP and BP affected microbiota composition and short-chain fatty acid (SCFA) production differently across enterotypes. The Bifidobacterium cluster showed significantly reduced alpha diversity, with the direction of change in the gut microbiota composition being different from that of other subjects. Additionally, SCFAs significantly increased, with the highest increase in the Bifidobacterium cluster. In this cluster, metabolic pathways related to SCFAs (i.e., starch and sucrose metabolism and glycolysis/gluconeogenesis) were altered. Conversely, Prevotella-dominant feces exhibited fewer changes in SCFAs and a lower increase in Bifidobacterium abundance than the others. These findings highlight that RP and BP elicit enterotype-specific responses in the gut microbiota composition and SCFA production, emphasizing the importance of enterotypes in personalized nutrition.