S22 - Session P2 - Natural Colorants specifications - Development of anthocyanin-rich raspberry juice powder for potential applications in the beverage industry: effect of carrier agents

Authors: Olaniyi Fawole *, Kaseke Tafadzwa, Confidence Nthimole

This research focused on the value-adding potential of raspberry juice into shelf-stable anthocyanin-rich powder for potential application in the beverage industry. Raspberry juice obtained from raspberry fruits was encapsulated separately using gum Arabic (GA), maltodextrin (MT), and waxy starch (WS) (10:1) and freeze-drying to develop raspberry juice powders (RJP). The powders were characterized based on their physicochemical, phytochemical, rheological and antioxidative properties. RBJP produced with GA and WS exhibited higher yield percentages (12.70% and 11.34, respectively), while MT yielded 9.73 % powder. Solubility of the RJP varied significantly with MT and GA encapsulated powders exhibiting higher solubility (60.83% and 60.25%, respectively) compared to WS (54.52%). Nevertheless, there were no significant differences between the powders with regards to their hygroscopicity. WS encapsulated RBJP appeared significantly lighter (L* = 36.93; a* = 48.8) than MT (L*= 34.46; a*= 56.86) and GA (L*= 31.27; a* = 53.53). Encapsulating with GA and MT resulted in bulkier RJP, with bulk density values of 60.25% and 60.83%, respectively, while waxy starch (54.52%). RBJP from WS showed the highest total phenolic content (TPC) (3.33 mg GAE/g DM) followed by MT (3.02 mg GAE/g DM) and lastly GA (2.93 mg GAE/g DM). MT and WS powders were characterized with higher radical scavenging activity (RSA) (54.55% and 53.31%, respectively), whereas GA powder had the least RSA (33.20%). Given their ability to retain or preserve quality attributes such as solubility, bulk density and colour, and functional attributes, RBJP from MT and GA have great potential for application in the food industry.