Functional, morpho-structural characteristics, and bioaccessibility of rice and insect protein enriched persimmon particles: effects of carrier agents for fluidized bed drying

Abstract

In this study, we evaluated the effect of rice protein (RP), insect protein (IP), and their mixture (RIP) as carrier agents for fluidized bed drying (70 °C) of persimmon juice (PJ) and concentrated extract of its bagasse (PB) on process yield, functional and morpho-structural characteristics, and bioaccessibility. All experimental procedures were conducted in a controlled laboratory environment at 25 ± 2 °C and 65 % relative humidity. Analyses of bioactive compounds were performed in the absence of light to prevent photodegradation. A simple protocol was developed, yielding particles with protein content (15.23–25.73 %) and high β-carotene retention. The process achieved yields ranging from 34.40 % to 43.25 %, forming particles with attractive colors, good solubility (>60 %), low hygroscopicity (<15 %), and high water absorption capacity (76.89–86.81 %). The IP showed better β-carotene retention compared to RP, with RIP combination further enhancing this compound's retention in the particles. In vitro digestibility also indicated that RIP increased the bioaccessibility of β-carotene, which was more bioaccessible in PJ (12.17 %) and PB (17.64 %). The PJ particles (19.44–20.16 μm) exhibited spherical and rough geometry, while PB particles (37.09–44.65 μm) were heterogeneous and fragmented. Additionally, both groups showed an amorphous character with traces of crystallinity. Overall, the drying method and protein carrier can be tailored to produce protein-rich fruit particles with desired β-carotene concentration and bioaccessibility.