We aimed to investigate the effect of citrus peel powder (CP) on the physicochemical, antioxidant, and sensory properties of Yanggaeng when treated with various levels (CON (0%), CP2 (2%), CP4 (4%), and CP6 (6%)) of CP. With an increase in CP content, Yanggaeng displayed a significantly elevated free radical scavenging rate, as indicated by increased 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging rates, as well as ferric reducing antioxidant power (FRAP). Furthermore, the addition of CP significantly reduced the pH and increased Brix values compared to the control (CON). CP treatment also exhibited a dose-dependent effect on colorimetric properties, resulting in decreased L* and increased a* and b* values. Moreover, CP addition changed the textural characteristics of Yanggaeng, escalating gumminess, hardness, and chewiness, while reducing adhesiveness. In terms of consumer preferences, Yanggaeng containing 4% CP (CP4) closely resembled CON in terms of attributes such as flavor, taste, sweetness, chewiness, purchase intent, and overall acceptance. However, Yanggaeng containing 2% (CP2) or 6% (CP6) CP led to a decreased overall preference for Yanggaeng. In conclusion, based on our findings, CP4 appears to be the most suitable choice for enhancing both the physicochemical and sensory properties of Yanggaeng. Furthermore, adding CP to Yanggaeng serves as a foundation for novel food production incorporating CP.

Background/Objectives: Lactobacillus delbrueckii subsp. lactis CKDB001 (LL) has demonstrated anti-inflammatory, antioxidant, and lipid-regulatory effects in vitro and in vivo, including attenuation of hepatic steatosis and modulation of lipid metabolism. Given the known interactions between host metabolism and gut microbiota, these findings suggest a potential role for LL in modulating microbial composition under conditions of diet-induced obesity. This study aimed to investigate the microbiome-related effects of LL using an established murine model. To evaluate the effect of LL supplementation on gut microbial composition and predict microbial metabolic functions in mice with high-fat diet-induced obesity. Methods: Male C57BL/6J mice were fed a high-fat diet and administered LL orally for 12 weeks. Fecal samples were collected and analyzed using 16S rRNA gene sequencing. Microbial taxonomic profiles were assessed using linear discriminant analysis effect size, and functional predictions were performed using PICRUSt2. Results: LL supplementation significantly altered the gut microbiota by increasing the relative abundance of Lactobacillus and other commensal taxa while reducing the prevalence of pro-inflammatory genera such as Alistipes and Bilophila. Functional prediction analysis revealed a downregulation of lipopolysaccharide and ADP-L-glycero-β-D-manno-heptose biosynthesis pathways. Microbial functions associated with carbohydrate metabolism and short-chain fatty acid production were enriched in the LL-treated group. Conclusions: LL modulated gut microbial composition and suppressed pro-inflammatory microbial pathways while enhancing beneficial metabolic functions in high-fat diet-fed mice. These findings support the potential of LL as a safe and effective microbiota-targeted probiotic for managing obesity-related metabolic disorders.