Cold Pressed vs. Centrifugal Juice: Comparison in Terms of the Juice Yield, Physicochemical and Phytochemical Properties

Abstract

In this study, a juice beverage was prepared from pineapple, green apple, and kiwifruit using cold press and centrifugal juice extraction methods. In the first stage, the most preferred beverage formulation (60% pineapple, 35% green apple, and 5% kiwifruit) was selected according to the acceptance index (AI) calculated based on sensory analysis scores. Next, the performance of home-type cold-pressed juicers (CPJ) and centrifugal juicers (CDJ) was compared, considering the physical, chemical, and phytochemical properties of the mixed beverage. It has been determined that the juice yield performance of the cold pressing technique is better than the centrifuge method. For example, the juice yield of pineapple obtained by a cold press juicer (92%) was found to be higher than the centrifugal extraction method (47%). Although the pH of CDJ and CPJ beverages were similar, the total soluble solids content (°Brix), the color parameters (a*, b*, L*), the browning index (BI), and the turbidity of both beverages were significantly different. While the browning index (BI), L*, and b* values of the CPJ beverage were higher, the a* value was lower than that of the CDJ beverage. Additionally, the CPJ juice mixture was more turbid and phase separation was not observed as in the CDJ beverage. This study revealed that juices obtained by both squeezing methods contained comparable total phenolic content (TPC). For example, the amount of TPC for CPJ and CDJ was 867.25 ± 0.01 mg GAE/L and 922 ± 0.01 mg GAE/L, respectively. Furthermore, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of both beverages was not significantly different. It was concluded that the physical properties of juices extracted by CPJ were more satisfactory than those of CDJ. However, more studies are needed to compare the data obtained on the antioxidant activity and TPC amount of fruit juices using different measurement methods.