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The recovery of bioactive compounds from agro-industrial residues with green solvents in ultrasound-assisted extraction (UAE) processes represents an interesting alternative from environmental and economical perspectives. Here we investigated optimal conditions to improve the extraction of anthocyanins from blackberry pomace. The experimental data were fitted to the second-order polynomial model to obtain the regression coefficients, and three-dimensional (3-D) response surface plots were considered to represent the relationships between each variable on the response of total monomeric anthocyanin (TMA) content. The ultrasound-assisted process at an ultrasound amplitude of 40% for 10 min and a concentration of 25 mg/L resulted in the maximum TMA concentration of 1.39 ± 0.02 mg Cy3GlE /g. At these extraction conditions, the extract presented total polyphenol and flavonoid contents of 44.12 ± 0.17 mg GAE /g and 63.25 ± 0.53 mg QE /g, respectively. A total of 31 individual compounds, including anthocyanins, flavonols, and phenolic acids, were identified in the extract. Concentrations of cyanidin-3-glucoside and caffeic, gallic, and ellagic acids were 2.38 ± 0.09, 0.47 ± 0.01, 0.55 ± 0.01, and 0.48 ± 0.01 mg/g, respectively. Compared to the conventional extraction, the UAE represented an increase of 20.87% in total anthocyanins. Thus, the UAE at suitable conditions is suggested to recover bioactive compounds from blackberry pomace. Practical ApplicationsThe use of blackberry pomace to extract bioactive compounds is promising because it uses a by-product from the fruit processing industry. This study presents an innovative proposal of optimal process conditions to recover anthocyanins from blackberry pomace under ultrasound irradiation. The use of green solvents, as water, in ultrasound-assisted extraction (UAE) processes, represents an interesting alternative from environmental and economical perspectives, UAE process is a favorable, fast, efficient, and environmentally friendly method. The obtained blackberry pomace powder is an interesting ingredient to food and pharmaceutical industries, mainly due to the elevated concentration of added-value compounds. Besides the high amount

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Blueberry and raspberry pomace are a rich source of bioactive compounds that have not been commercially utilized yet, and ultrasound-assisted technology can efficiently extract these compounds. Also, the use of water as a solvent added to the ultrasound-assisted technology improves this eco-friendly process. Therefore, an aqueous eco-friendly extraction, including extraction time and ultrasound presence or absence (conventional extraction) was performed in order to extract bioactive compounds from blueberry and raspberry pomace. Response parameters included levels of anthocyanins, phenolic compounds, and flavonoids, and antioxidant activity determined by DPPH, ABTS, and FRAP methods. Analysis of variance results indicated that ultrasound-assisted extraction for 45 min. was feasible to extract the bioactive compounds. The antioxidant content of the extract obtained by the ultrasound-assisted process was 1.4 times higher on average and the total phenolic concentration was 1.6 times higher (for blueberry 5.02 and for raspberry 2.53 mg gallic acid equivalent/g) compared with those obtained by the conventional process. Thus, the ultrasound-assisted extraction method can be a profitable alternative to extract bioactive compounds from blueberry and raspberry pomace, as it is energy efficient, requires fewer chemicals, and produces less effluent. This eco-friendly technology is therefore viable for food, nutraceutical, and cosmetic industries, and also for reducing food waste.

The objective was to evaluate the extract stability of hibiscus in different conditions and the food application. Anthocyanins (TA), phenolic compounds (TP) and color, at: 4 and 25 °C, presence or absence of light, pH stability and FTIR were evaluated. Gelatin developed with hibiscus extract was submitted to sensory analysis. Light and temperature factors affected the stability of TP and TA throughout the storage.  Higher stability was observed at 4 ºC and absence of light (in relation to TA and TP respectively, 3% and 26% losses were observed in this condition against 43% and 39% at 25 °C with light). Regarding pH, it was observed that pH change affected the absorbance and color in the hibiscus extract. Finally, the hibiscus extract, when added at the highest concentration into gelatin, was the most accepted by tastes, and scored 7 (like moderately) for color and global acceptance.