Clarification of red grape juice by amine-functionalized magnesium silica aerogel.

ABSTRACT

The clarification conditions and the selection of the clarification agent are pivotal in eliminating the haze components from red grape juice (RGJ) while minimizing the loss of functional color components. In this context, we synthesized a water glass-based APTES functionalized magnesium silica aerogel (MSA-NH3) incorporating 61.44 molecules/nm2 of amine groups, resulting in a positively charged zeta potential value of 33.9 mV (pH 3.4) for clarification of RGJ by targeting negatively charged polyphenols. The optimum clarification conditions using MSA-NH3 were determined as 0.18 g MSA-NH3/L RGJ, 20 °C, and 60 min through the application of Box-Behnken design. Under these conditions, MSA-NH3 exhibited excellent adsorption of haze components (3.61 NTU), outperforming the commercial bentonite-gelatine combination (BGC) (5.45 NTU). Furthermore, it exhibited greater efficacy in preserving anthocyanins while adsorbing browning components. MSA-NH3 has a high potential to serve as a functional alternative clarification agent in the beverage industry due to its promising clarification performance.