The Influence of Microwave-Assisted Extraction on the Phenolic Compound Profile and Biological Activities of Extracts from Selected Scutellaria Species.

The aim of the study was to investigate the effects of microwave-assisted extraction (MAE) conditions (microwave power, extraction time, and ethanol concentration) on the efficiency of the extraction of phenolic compounds from selected plant species belonging to the genus Scutellaria (i.e., Scutellaria baicalensis and Scutellaria lateriflora). The extracts from selected Scutellaria species were examined to establish the total phenolic content and the in vitro antioxidant and anti-inflammatory activity. The antioxidant capacity was determined by the ferric reducing antioxidant power (FRAP) and 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity methods. The anti-inflammatory activity was evaluated through the lipoxygenase (LOX) inhibitory assay. The phenolic profile of the extracts was characterized using ultra-high performance liquid chromatography coupled with diode array detection and high-resolution electrospray ionization mass spectrometry (UHPLC-DAD/ESI-HRMS/MS). Depending on the type of solvent and the extraction conditions used, the extracts obtained from selected Scutellaria species showed different total and individual phenolic content, as well as different antioxidant and anti-inflammatory properties. The results showed that all Scutellaria extracts had high total phenolic content and exhibited strong ferric ion reducing power and free radical scavenging capacity and a significant ability to inhibit the LOX activity. In general, the 70% ethanol extracts contained more phenolic compounds, mainly flavones, flavanones, and their derivatives, and showed greater in vitro biological activity than other extracts. The highest levels of phenolic compounds and the strongest antioxidant and anti-inflammatory potential were found in extracts from the roots of S. baicalensis. Optimal extraction conditions for all the plant materials tested were determined as the microwave power of 63 W, extraction time of 10 min, and 70% ethanol as the solvent.

Fresh and Stored Sugar Beet Roots as a Source of Various Types of Mono- and Oligosaccharides.

Although sugar beets are primarily treated as a source of sucrose, due to their rich chemical composition, they can also be a source of other carbohydrates, e.g., mono- and oligosaccharides. The study focused on both fresh beet roots and those stored in mounds. Our studies have shown that, in addition to sucrose, sugar beet tissue also comprises other carbohydrates: kestose (3.39%) and galactose (0.65%) and, in smaller amounts, glucose, trehalose and raffinose. The acidic hydrolysis of the watery carbohydrates extracts resulted in obtaining significant amounts of glucose (8.37%) and arabinose (3.11%) as well as xylose and galactose and, in smaller amounts, mannose. An HPSEC liquid chromatography study of the molecular mass profile of the carbohydrate compounds present in the beet roots showed alongside the highest percentage (96.53-97.43%) of sucrose (0.34 kDa) the presence of pectin compounds from the araban group and arabinoxylooligosaccharides (5-9 kDa) with a percentage share of 0.61 to 1.87%. On the basis of our research, beet roots can be considered a potential source of carbohydrates, such as kestose, which is classified as fructooligosaccharide (FOS). The results of this study may be helpful in evaluating sugar beets as a direct source of various carbohydrates, or as a raw material for the biosynthesis of fructooligosaccharides (FOS) or galactooligosaccharides (GOS).

Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production.

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

Assessment of physicochemical and thermal properties of soluble dextrin fiber from potato starch for use in fruit mousses.

BACKGROUND: Fruit mousses are products with a relatively low amount of dietary fiber in a single portion, but with additional portions of soluble fiber they may be good alternative to fiber-rich snacks as take-away food. In the present study, the properties of new soluble dextrin fiber (SDexF) from potato starch were assessed to establish whether it could be used to enrich fruit mousses. The properties of SDexF that can affect processing and storage stability of enriched mousses were studied and compared with those of native potato starch and semiproducts (resulting from various drying temperatures). The effect of the addition of SDexF on the pasting properties of mousse was also analyzed. RESULTS: The application of food-grade hydrochloric and citric acids as catalysts in the dextrinization of food-grade potato starch allowed to SDexF to be obtained. Despite the differences in characteristics of the semiproducts, the final SDexF preparations were very similar in the meaning of solubility, dextrose equivalent (DE), retrogradation, and pasting properties. SDexF preparations were characterized by a significantly lower retrogradation tendency, peak viscosity, final viscosity, and gelatinization enthalpy in comparison with both native starch and semiproducts. Soluble dextrin fiber was successfully added to banana-apple mousse. The addition of SDexF to mousse did not cause any undesirable changes to the viscosity of the product, and surprisingly even resulted in mousse with lower viscosity. Turbidity and RVA studies revealed that SDexF was stable and retrogradation processes can be negligible during storage. CONCLUSION: The SDexF obtained from potato starch can be a novel functional substance to increase the dietary fiber content of fruit or fruit and vegetable mousses. © 2020 Society of Chemical Industry.