Influence of different thermal treatment methods on the processing qualities of sesame seeds and cold-pressed oil

• Thermal treatment methods including explosion-puffing, microwave and roasting were used. • Explosion-puffed oil had higher content of tocopherols, lignans and phytosterols. • Microwaved oil contained maximum value for sesamol. • Explosion-puffing achieved the least effect on content of protein and most amino acids. This study investigated the impact of thermal treatments (explosion-puffing, microwave, and roasting) on the processing qualities of sesame seeds and cold-pressed oil. The scanning electron microscopy (SEM) showed fissures and micropores appeared in the seeds after thermal treatments. The microwave treatment promoted the maximum conversion of sesamolin into sesamol in the sesame oil. Compared with other treatments, explosion-puffing treatment resulted in most significant increases in the multiple beneficial phytochemicals, as well as in vitro antioxidant properties determined by 2,2-dipheny1-1-picrylhydrazyl radical (DPPH) radical scavenging activity, Ferric reducing antioxidant power (FRAP) and oxidative stability index (OSI). Additionally, crude protein, total amino acids (TAA) and protein structure (tertiary and second structure) notably changed during thermal treatment processing ( P < 0.05), and explosion-puffing achieved minimal reduction in the first two indicators. According to the results, explosion-puffing might be a preferred treatment method for industrial sesame processing based on the improvement in the quality specifications.