Comparing the antioxidant properties and volatile compounds of carrot-orange juice blend processed through varied chemical, pasteurization and ultrasound conditions

Abstract

Ultrasound technique is one of the green technologies that is being utilized widely for varying food processes. Our aim in this study was to carry out ultrasonication, pasteurization and chemical preservation (Potassium metabisulfite) techniques on a carrot-orange juice blend. Additionally, the effect of these treatments on the storage period of about 21 days was also determined. The study displayed an array of results under the effect of different treatments. Throughout the storage period of 21 days’ significant results were presented by the carrot juice blend subjected to the ultrasound technique (25 min) giving the highest values for total phenolic content (25.56 ± 1.29 mg GAE/100 mL), total antioxidant activity (573.48 ± 2.29 mg Trolox /100 mL), DPPH (32.32 ± 1.83 %) and reducing power (45.45 ± 1.92 mg AAE/100 mL) with least deterioration, followed by the blends treated with potassium metabisulfite (KMS) and pasteurization. The physicochemical analysis showed a non-significant effect of treatments on pH and total soluble solids (oBrix) of carrot-orange juice blends whereas, the changes in color parameters L*, a* and b* were noted to show changes in treated blends. Similarly, the results for the GC–MS quantification of volatile compounds displayed the highest concentrations in the ultrasonicated blends as compared to other techniques. The peak quantity was obtained for the hexanal (9903.43 ± 7.61 μg.kg−1) followed by 3-Methylbutanal (2638.7 ± 5.44 μg.kg−1), terpinolene (2337.16 ± 5.28 μg.kg−1), elemicin (2198.28 ± 5.28 μg.kg−1), myristicin (1936.62 ± 6.72 μg.kg−1). The use of sonication can effectively enhance the nutritional qualities of juice, as perceived by consumers.

Keywords

• Carrot-orange juice blend
• Ultrasonication
• Pasteurization
• Chemical preservation
• Anti-oxidative properties
• Aromatic compounds