Enhancing encapsulation efficiency: Konjac glucomannan hydrolysate as a novel coating material for flavone derivatives in rice leaves extract

Abstract

This study aimed to develop a novel coating material from Konjac Glucomannan Hydrolysate (KGMH) to flavone derivates from rice leaves extract (RLE). A suitable process for producing KGMH solution with different degrees of polymerization (DP) by enzymatic treatment was developed. Mannanase enzyme (250 and 150 units/g) were used in the hydrolysis process to obtain KGMH with lower (DP4 – 7) and higher DP (DP7 – 10), respectively. The solution was then used as a coating material in spray drying with an inlet air temperature of 190 °C, and the powder characteristics were assessed. The results showed that although the KGMH produced a lower production yield (64%–66%) compared to gum Arabic (72.45% ± 0.74%), KGMH was superior in terms of encapsulation efficiency of bioactive compounds (85%–95%) and antioxidant activity retention (90%–100%). FTIR spectra and X-ray diffraction confirmed the success of encapsulation by KGMH in the spray drying process. KGMH DP7-10 has successfully improved the bioaccessibility of Tricin O-glycoside after digestion. Furthermore, adding RLE encapsulated with KGMH enhanced and preserved tea products' bioactive compound content and antioxidant activity (3%–10% lower than after 24 days of storage).