Abstract
In this study, the influence of stevia addition and sonication processing parameters on the phenolic content and profile as well as the steviol glycosides of strawberry juice-based samples was investigated. For this purpose, three matrices—control samples of strawberry juices without green stevia powder (CS), strawberry juices with green stevia powder (JGSP), and sonicated juices with green stevia powder (SJGSP)—were prepared. For sonication purposes, different conditions regarding probe diameters (7 mm and 22 mm), amplitudes (50%, 75%, and 100%), and time (15 min, 20 min, and 25 min) were tested. The results that were obtained upon the measurement of the total phenolic content, total flavonoids, steviol glycosides, and antioxidant capacity showed significant differences according to the matrices evaluated, obtaining overall higher values in the samples with stevia added. Moreover, when sonication was evaluated, it was found that a higher amplitude (100%), a larger probe diameter (22 mm), and a longer sonication period (25 min) led to higher values. Flavones such as luteolin and apigenin were identified and quantified in JGSP and SJGSP, while they were not found in CS. Besides these phenolic compounds, kaempferol, quercetin, pyrogallic acid, 4-methylcatechol, and 4-methoxybenzoic acid were also identified and quantified. Similarly to the total phenolic compounds, total flavonoids, and total antioxidant capacity, an increased amount of these compounds was found in SJGSP, especially after using the most intense sonication conditions. Therefore, the use of sonication together with stevia added could be a useful tool to preserve strawberry juices, increasing at the same time the sweetness and the antioxidant value of the beverages.
Highlights
Green stevia powder (GSP) is a rich source of various nutrients and phytochemicals such as polyphenols [1,2] with strong antioxidant activity [3,4,5]
Significant differences were observed in the total phenolic content (TPC) of sonicated juices with green stevia powder (SJGSP) according to the sonication processing conditions, varying from 962.69 mg GAE L−1 (C1) to 1185.59 mg GAE L−1 (C18)
An increase (23%) in the TPC of the sample treated with the largest probe diameter (PD, 22 mm), amplitude (A) of 100%, and 25-min treatment was found compared to the juice sample treated with a PD of 7 mm and A of 50% for 15 min
Summary
Green stevia powder (GSP) is a rich source of various nutrients and phytochemicals such as polyphenols [1,2] with strong antioxidant activity [3,4,5]. It is a source of non-caloric sweeteners such as stevioside, steviolbioside, rebaudioside (A, B, C, D, E, F), dulcoside A, and rubusoside [6] from natural origin, which can be used in order to replace sugars in food products. The addition of GSP increases the amount of antioxidant bioactive compounds in the juices [8,9,10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
