A comparative study on stabilizing and releasing thymol by pre-formed V-type starch and β-cyclodextrin

Cyclodextrins (CD) are well known to form host-guest assemblies with hydrophobic compounds. As a structural homologue, starch-guest inclusion complexes (ICs) have become promising in the food, agriculture, and pharmaceutical industries due to their low cost and versatility. This study compared the stabilizing and releasing abilities for thymol of three kinds of pre-formed V-type starch (Water-V, Salt-V, and Alkali-V) and β-CD. The loading efficiency for thymol decreased in the order of Water-V > Alkali-V > CD > Salt-V when removing the free thymol. Water-V, β-CD, and their ICs had better thermal stability with maximum thermal decomposition temperatures over 320°C. Under non-cold chain daily storage conditions for 4 d, the percentage of thymol released from starch/CD-thymol ICs was 14% (Water-V), 35% (Salt-V), 34% (Alkali-V), and 43% (CD). The Water-V made ICs had good sustained release properties and long-term antibacterial activity, which kept strawberries fresh for 6 d without decay.