Influence of Soluble Fiber as a Carrier on Antioxidant and Physical Properties of Powders Produced Based on the Spray Drying of <i>Malvae arboreae flos</i> Aqueous Extracts

Abstract

The objective of this study was to assess the impact of inulin and pectin, wherein pectin replaced inulin with weight ranging from 2% to 8%, as wall materials on various aspects: bioactive component content, antioxidant and anti-inflammatory properties, bioavailability, powder recovery during the drying process, and selected physical characteristics of powders derived from Malvae arboreae flos aqueous extracts obtained through spray drying. Powders containing a soluble fraction of fiber demonstrated a recovery efficiency of over 50% during drying, along with low moisture content, water activity, and hygroscopicity, coupled with high solubility. The incorporation of pectin up to 8% did not significantly alter the color profile of the powders. However, at levels of 4% to 8% pectin, concave distortions and particle morphology cracks became noticeable, along with the potential to form agglomerates (evident when the span index ranged between 5.11 and 14.51). The substitution of inulin with pectin led to higher total contents of flavonoids (from 1.31% to 49.57% before digestion, and from 18.92% to 36.48% after digestion) and anthocyanins (from 45.79% to 78.56% before digestion, and from 65.45% to 521.81% after digestion) compared to samples containing only inulin as a carrier. Bioacceptability values exceeding 100% indicated effective preservation of compounds responsible for ferric-reducing antioxidant power, as well as the inhibition of xanthine oxidase and cyclooxygenase-2 across all samples.

Keywords

• black hollyhock flowers
• spray drying
• inulin
• pectin
• flavonoids
• anthocyanins