Structural mechanism study on the retention and slow release of aroma molecules by starch in the form of V6-type crystals

Abstract

The structural evolution of V6-type starches was analyzed from the microscopic level—single-helix conformation, unit cell structure, and lamellar structure—to the macroscopic level—crystalline structure and crystal properties. It also identified the mechanisms by which the structure of V-type starch affected aroma retention. Three V6-type starches, i.e. V6I-, V6II-, and V6III-type, with different structural characteristics, were prepared using 1-octanol, 1-octen-3-ol, and γ-octalactone, respectively. V6I-type starch, with its higher content of single helices and greater structural variability in both unit cell and lamellar structures, showed a significant increase in aroma retention at 12–20 h, resulting in a high retention rate (R = 59 %). In contrast, V6II- and V6III-type starches, with lower structural variability and less dense V-type crystals, exhibited higher initial retention rates (t ≤ 12 h) but lower final retention rates of 46 % and 35 %, respectively. Correlation analysis indicated that the microstructure had a cumulative effect on the macroscopic crystalline structure, with the highest positive correlation between aroma retention rate and crystalline structure (relative crystallinity) as well as crystal performance (short-range order and structural stability). V6III-type starch showed the best slow-release effect, with a value of 39.02 %. These findings illuminate structure-driven strategies for tailoring aroma retention and release in V6-type starch.