The Impact of Bentonite Fining on Apple Juice Clarity and Sodium Content

Abstract

In the experiment, four calcium bentonites (Ca bentonites) with different sodium contents in their activator were used for the pretreatment fining before the pasteurization of apple juice. The percentages of sodium carbonate in the activator of bentonites were 0% (B-0), 30% (B-30), 50% (B-50) and 70% (B-70). For the determination of correlation between bentonite dosage and juice turbidity after fining, the apple juice was treated with the following dosages: +40 g/hL, +50 g/hL, +60 g/hL, +70 g/hL and +80 g/hL. Bentonites with added sodium in the activator achieved much better juice clarification compared to pure Ca bentonite. Better clarification of apple juice was obtained by bentonites with the higher sodium content in the activator and also in treatments with higher dosages (g/hL). All bentonites with added sodium in activator released significantly more sodium into the juice (6.7– 8.4 mg/L) compared to the control and pure Ca bentonite (3.2–3.4 mg/L). At higher doses of bentonite, the increase in sodium release into the juice was greatest with bentonite B-70. Bentonite with a small addition of sodium in the activator (B-30) was the best compromise in terms of juice clarification and sodium release.