Effects of annealing and plasma-activated water on the multiscale and functional properties of jackfruit seed starch

The annealing treatment (ANN) combined with plasma-activated water (PAW) showed strong potential for starch modification. However, the effects of incubation time and ratios during ANN-PAW on jackfruit seed starch (JSS) remain unclear. Therefore, this study explored changes in JSS modified by ANN-PAW at different durations (24 h and 36 h) and ratios (1:2 and 1:4). Microstructural analysis indicated that pores, fissures, and erosions appeared on the surface of starch granules, along with larger particle sizes after ANN-PAW treatment. X-ray diffraction and Fourier-transform infrared spectroscopy revealed higher RC and an ordered structure, accompanied by higher peak viscosity and better hydration properties. The shear resistance of modified starches was significantly improved after 36 h of ANN-PAW treatment. Moreover, the 36-ANN-PAW 4 had the highest resistant starch content (76.51%) and the lowest hydrolysis (23.51%). Therefore, an ANN combined with PAW treatment displayed the most desirable properties in JSS, particularly at a 36 h duration and a 1:4 ratio. It not only enhanced the hydration and rheological properties of JSS, improving its machinability, but also reduced the in vitro digestibility, thereby further increasing its health index. These findings may help optimize the processing conditions for extending the application range of JSS to be used as a resistant starch-based ingredient.