RESUMEN
The aim of the research was to develop microencapsulated powders of bilberry and chokeberry extracts via the spray drying technique. Two biopolymers, pectin alone and in combination with HP-ß-CD, were used to preserve the antioxidant, hypoglycemic, photoprotective, and antimicrobial bioactivity of the berry leaf extracts. Moreover, the formed powders were characterized in terms of technological, chemical, and several biological properties. The obtained micro-sized powders (mean average particle diameter from 3.83 to 5.94 µm) demonstrated a process yield of up to 73%. The added biopolymers improved the flowability and cohesive properties of the powders and increased their thermal stability to 170 °C. The total content of polyphenolics in the powders ranged from 323.35 to 367.76 mg GAE/g DW for bilberry and from 186.85 to 227.59 mg GAE/g DW for chokeberry powders; meanwhile, chlorogenic acid was the predominant compound in powders. All samples showed stronger α-glucosidase inhibitory activity (IC50 values ranged from 5.00 to 19.59 µg/mL) compared with the reference standard. The study confirmed that spray drying is a suitable method for the preservation of the polyphenolic-rich extracts, while the addition of carriers has a positive effect on the improvement of microencapsulated powders' properties.
RESUMEN
The aim of this study was to develop, for the first time, anthocyanin-enriched fractions from black raspberry pomace (BRP) using ultrasound-assisted extraction (UAE) via sonotrode and the Particles from Gas-Saturated Solutions (PGSS) process. UAEs with different amplitudes and sonication times were evaluated and showed relevant effects on the yields of target analytes. The raspberry pomace extracts were formulated in a powder form by PGSS using glyceryl monostearate as a carrier at different extract-to-carrier ratios of 1:11, 1:5, and 1:3. The effects of all variables were evaluated in terms of extraction yield, total phenolic content, and encapsulation yield. UAE was strongly affected by amplitude, and the highest amplitude (100%) provided the best results for extraction yield and total phenolics. HPLC of UAE extracts and powders was utilized for quantification of polyphenol compounds, showing cyanidin-3-rutinoside as a main compound, followed by cyanidin-3-glucoside, rutin, ellagic acid, and gallic acid. These results show that these time-efficient and high-performance techniques enable the production of natural fractions from industrial BRP with acceptable characteristics to be used for the development of nutraceuticals and different food formulations.
RESUMEN
To study the efficiency of two green-based extraction techniques for the isolation of bioactive constituents from black elderberry press cake, changes in phenolic compounds and main anthocyanin contents were analyzed. Polyphenolic content was correlated with antioxidant and antidiabetic potential by radical-scavenging activity and monitoring of α-amylase inhibition. Black elderberry press-cake extracts were obtained by ultrasound-assisted (UAE) and microwave-assisted (MAE) extractions under different extraction conditions. High-performance liquid chromatography (HPLC) analysis revealed that cyanidin-3-sambubioside and cyanidin-3-glucoside were the principal anthocyanins in all the obtained extracts, with their content being highest in MAE obtained at 80 °C over 5 min. The same extract induced two-fold higher antioxidant activity (IC50 6.89 µg/mL) and α-amylase inhibitory potential (IC50 2.18 mg/mL) in comparison to UAE extracts. The main compositional differences between extracts obtained by the same extraction technique were assigned to the extraction temperature. A principal component analysis confirmed that the antidiabetic feature is to be attributed to the rich content of anthocyanins in black elderberry press cake. Our results indicate the great potential of underutilized black elderberry press cake for the development of novel food and herbal formulations due to notable anthocyanin contents highly correlated with antidiabetic activity.