Bioactive Compounds and Physicochemical Properties of Fruit – Orange Juice Mixes with Rosemary Extract

Abstract

In the present study a variety of fruit juices (pomegranate, strawberry, apple, plums and blackberries) each was mixed with equal amounts of orange juice (1:1) and different levels of rosemary extract (5, 10, 15, ml/L) were developed. Sensory evaluation tests were performed to choose the most acceptable level of rosemary added to the fruit-orange juices. Physicochemical and bioactive determinations were also assessed. Sensory evaluation tests showed that 10ml/L rosemary extract added to all tested fruit-orange juices was highly appreciated by panelists except blackberry-orange juice at 5ml/L. The physicochemical tests as measured by TTA%, pH and TSS revealed that the addition of rosemary extract did not significantly affect most of the tested parameters for all tested fruit-orange juices and their controls, and they were at the normal range of commercial juices. Vitamin C the total sugar content showed a variation ranging between 2.54 -28.11mg/100ml and 6.51-19.35%, respectively. Results also indicated that the addition of rosemary extract significantly enhanced the increase in total phenolics (TP) and flavonoids (TF), where blackberry (BO5), strawberry (SO10) and pomegranate (PO10) exhibited the highest TP values, respectively whereas, SO10, BO10 and RO10 exhibited the highest TF values, respectively. SO10, exhibited the highest anthocyanin content (800mg/L) as compared to all other fruit- orange juices. The antioxidant activity (% inhibition) measured by DPPH radical scavenging assay showed that SO10, PO10, and RO10 (plum) exhibited the highest antioxidant activities as compared to their controls and the other fruit-orange mixes. The study postulates that these beverages could provide health promoting benefits against oxidative stress related diseases.