Effect of probe ultrasonication and β-Cyclodextrin on bitterness reduction and enhancement of biochemical properties of Citrus limon Burm juice

Lemon is a globally cultivated citrus fruit crop that has gained a significant market share in recent years. Lemon tends to taste bitter on prolonged storage periods, leading to undesirable changes in juice quality. Therefore, the study aimed to enhance lemon juice quality by reducing bitterness through combined probe ultrasonication and β-cyclodextrin treatment. Ultrasonic treatment of 20 kHz, an incubation period ranging from 20 to 80 minutes, was applied to the juice and its effect on pH, total titratable acidity (TA), total soluble solids (TSS), ascorbic acid, total phenolic content (TPC) and antioxidant activity was evaluated. Batch debittering of limonin was carried out by adding β-cyclodextrin at concentrations ranging from 0.25% to 2.50% for 20, 60 and 80 minutes of sonication treatment. The study also examined the influence of sonication treatments on microbial load, revealing significant reductions corresponding to 60 minutes of sonication. The sound waves generated at 20KHz from ultrasonication, including β-cyclodextrin, could help to break down the cyclodextrin molecules and improve the encapsulation efficiency of the target compound. Moreover, increased water-soluble polyphenolic compounds due to cyclodextrin addition can enhance the lemon juice processability at an industrial scale. The present study emphasized the development of cost-effective β-cyclodextrin debittered lemon juice in combination with ultrasonic treatment that improved juice quality at room temperature (25 °C±1 °C).