Structural characterization and prebiotic activity of oligosaccharides derived from sesame meal produced by different oil extraction methods.

Sesame meal, the primary by-product of the sesame oil industry, still lacks high-value utilization. In this study, oligosaccharides (ORPM, OCPM, OSEM, OSPEM) were extracted from sesame meal produced by roasting-pressing, cold-pressing, solvent extraction, and subcritical propane extraction, respectively. A three-level and three-factor Box-Behnken design (BBD) integrated with response surface methodology (RSM) was adopted for the optimization of extraction parameters, including ethanol concentration, liquid-solid ratio, and ultrasonic-assisted extraction time. The molecular weight of all samples ranged between 424 Da and 1167 Da, and OSPEM showed the highest yield and sugar content among all samples. OSPEM had the highest glucuronic acid residue ratio (27.39 %). ORPM exhibited a stronger free radical scavenging capacity than the other three oligosaccharides. OSEM and OSPEM exhibited a more effective proliferation-promoting effect on Lactobacillus plantarum Pc1 and Lactococcus lactis ZZUPF9, while inhibiting the proliferation of harmful bacteria. These results suggested that the sesame kernel oligosaccharides had potential prebiotic activity linked to their structural features. This study provides valuable insights for facilitating the development and application of functional oligosaccharides derived from sesame meal.