Effect of the Addition of Different Vegetal Mixtures on the Nutritional, Functional, and Sensorial Properties of Snacks Based on Pseudocereals

Quick meals available in markets are popular among consumers. Generally, these products are not recognized as functional foods owing to nutrient-poor composition. In this study, energy snack bars were developed with different formulations, using puffed quinoa, amaranth, cacao liquor, and coconut oil, and the effects of the addition of commercial vegetal mixtures (VM) on nutritional and functional properties were assessed. VM addition showed significant effects on the protein, lipid, and fiber contents, phenolic compounds (PHC) content, and antioxidant activity of the snacks. The control snack showed higher levels of free and bound PHC. The oxygen radical absorbance capacity (ORAC) analyses recorded highest values of free PHC (9392.7 μmol TE/100 g dry weight) in PC65 (concentrate based on a combination of vegetal proteins), whereas the highest bound PHC levels of 47,087 and 46,531 μmol TE/100 g dry weight were observed in PC65 and the control snacks, respectively. Sensorial attributes assessment provided a high score on the hedonic scale, wherein panelists detected no differences among the samples. Altogether, the selection of non-conventional ingredients with high antioxidant activities emerged as a successful strategy to produce sensory acceptable meals.

Determination of antioxidant capacity in some foods by oxygen radical absorbance capacity (ORAC)

Oxygen radical absorbance capacity (ORAC) assay has been applied to determine the Hydrophilic – ORAC index in food. The method measures antioxidant scavenging activity against peroxyl radical induced by 2,2′-azobis(2-amidino-propane) dihydrochloride (AAPH) at 37ºC, used fluororescein as the fluorescent probe. The antioxidant capacity is measured by assemssing the fluorescence decay curve (AUC) of the sample as compared to that of the blank in which no antioxidant is present. Results expressed in ORAC units, equivalent to micromole Trolox per 100 grams sample (Trolox equivalent). The method was shown with high selectivity, a wide linear range, from 5 to 50µM Trolox with linear coefficient R2 = 0.9987. The recovery from 93.2% to 104.4% and repeatability (RSD) was less than 6.60%. The limits of detection and quantitation were 5 and 10µM Trolox, respectively. The method has been applied to determine of H-ORAC index in 65 samples including vegetables, fruits, vegetable products and health supplements with content ranging from 720 µM TE/100g to 310878 µM TE/100g.

Telaah Metode Pengujian Aktivitas Antioksidan pada Teh Hijau (Camellia sinensis (L.) Kuntze)

Green tea (Camellia sinensis (L.) Kuntze) is a trendy herbal drink with many benefits, one as an antioxidant. Catechin from the flavonoid class (polyphenols) in green tea is responsible for determining tea's antioxidant properties. Much research measures antioxidant activity in green tea, so it has to compare the antioxidant activity testing method to see which one method is better based on their mechanism in action. The antioxidant activity testing methods were used are DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS, FRAP (Ferric Reducing Antioxidant Power), CUPRAC (Cupric Reducing Antioxidant Capacity), and ORAC (Oxygen Radical Absorbance Capacity). The results showed that the highest antioxidant activity in green tea was obtained using the ABTS method expressed in Trolox Equivalent, equal to 3210 μmol TE/g with a total phenol of 240.73 mg GAE/g.

Recovery of Bioactive Compounds from Strawberry (Fragaria × ananassa) Pomace by Conventional and Pressurized Liquid Extraction and Assessment Their Bioactivity in Human Cell Cultures

Pressing strawberries for juice generates large amounts of pomace, containing valuable nutrients and therefore requiring more systematic studies for their valorization. This study compared conventional solid-liquid (SLE) and pressurized liquid (PLE) extractions with ethanol (EtOH) and H2O for the recovery of bioactive compounds from strawberry pomace. The composition and bioactivities of the products obtained were evaluated. Among 15 identified compounds, quercetin-3-glucuronide, kaempferol-3-glucuronide, tiliroside, ellagic, malic, succinic, citric and p-coumaric acids were the most abundant constituents in strawberry pomace extracts. SLE-EtOH and PLE-H2O extracts possessed strong antioxidant capacity in DPPH• and ABTS•+ scavenging and oxygen radical absorbance capacity (ORAC) assays. Cytotoxicity, antiproliferative and cellular antioxidant activities in human cells of PLE-EtOH and PLE-H2O extracts were also evaluated. PLE-EtOH and PLE-H2O extracts possessed strong antioxidant activity, protecting Caco-2 cells upon stress stimuli, while PLE-EtOH extract showed higher antiproliferative activity with no cytotoxicity associated. In general, the results obtained revealed that properly selected biorefining schemes enable obtaining from strawberry pomace high nutritional value functional ingredients for foods and nutraceuticals.

EPR spectroscopy investigation of oxygen radical production by methylene blue and indocyanine green in aqueous solutions under laser irradiation in the context of antibacterial photodynamic therapy

Introduction: Antibacterial photodynamic therapy is a promising treatment modality in the anti-infective therapy of numerous oral diseases. It involves photo activation of a reactive substance (dye), thus releasing reactive oxygen species (ROS-radicals) which are highly destructive to the bacterial cell. However, thorough investigation of radical production properties of different dyes is not common in literature. Aim: The aim of this study was to investigate and evaluate oxygen radical-producing potential of two commonly used photoactive dyes in the context of antibacterial photodynamic therapy. Materials and methods: The radical-producing properties of two commonly used dyes for photodynamic therapy in oral medicine, methylene blue and indocyanine green, irradiated under laser irradiation are investigated using electron paramagnetic resonance (EPR) spectroscopy. The detection of reactive oxygen species is performed with “spin-trapping” technique. Results: The selected photoactive dyes showed promising yields of reactive oxygen species (ROS) in aqueous solutions. The comparative analysis of the results deemed methylene blue as the more productive photoactive agent. Conclusions: By employing the spin-trapping technique, this study indicates EPR-spectroscopy as a promising method of relative quantification of reactive oxygen species released by the photodynamic reaction in aqueous solutions.