Ultrasound Treatment on Stability of Total and Individual Anthocyanin Extraction from Blueberry Pomace: Optimization and Comparison

Green Solvents for Extraction of Natural Food Colorants from Plants: Selectivity and Stability Issues

Consumers associate the color of food with its freshness and quality. More and more attention is being paid to natural colorants that bring additional health benefits to humans. Such natural substances are the carotenoids (yellow to orange), the anthocyanins (red to blue), and the betalains (red and yellow), which are very sensitive to exposure to light, air, high temperatures, and chemicals. Stability and diversity in terms of color can be optimized by using environmentally friendly and selective extraction processes that provide a balance between efficacy, safety, and stability of the resulting extracts. Green solvents like water, supercritical fluids, natural deep eutectic solvents, and ionic liquids are the most proper green solvents when combined with different extraction techniques like maceration, supercritical extraction, and ultrasound-assisted or microwave-assisted extraction. The choice of the right extracting agent is crucial for the selectivity of the extraction method and the stability of the prepared colorant. The present work reviews the green solvents used for the extraction of natural food colorants from plants and focuses on the issues related to the selectivity and stability of the products extracted.

Anthocyanins from Agro-Industrial Food Waste: Geographical Approach and Methods of Recovery-A Review

Drastic growth in the amount of global food waste produced is observed every year, not only due to incessant population growth but also economic growth, lifestyle, and diet changes. As a result of their increasing health awareness, people are focusing more on healthy diets rich in fruits and vegetables. Thus, following worldwide fruit and vegetable consumption and their processing in various industries (juice, jams, wines, preserves), significant quantities of agro-industrial waste are produced (pomace, peels, seeds) that still contain high concentrations of bioactive compounds. Among bioactive compounds, anthocyanins have an important place, with their multiple beneficial effects on health; therefore, their extraction and recovery from food waste have become a topic of interest in recent years. Accordingly, this review aims to summarize the primary sources of anthocyanins from food waste and the novel eco-friendly extraction methods, such as pulsed electric field extraction, enzyme-assisted extraction, supercritical fluid extraction, pressurized liquid extraction, microwave-assisted extraction, and ultrasonic-assisted extraction. The advantages and disadvantages of these techniques will also be covered to encourage future studies and opportunities focusing on improving these extraction techniques.

Recovering high value-added anthocyanins from blueberry pomace with ultrasound-assisted extraction

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Food waste blueberry pomace offers a high potential to recover anthocyanins.

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Ultrasonic-assisted extraction of anthocyanins was optimized by Box-Behnken design.

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The optimal parameters of ultrasonic treatment were 40 °C and 400 W for 40 min.

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Highly purified blueberry anthocyanins were obtained after SCX cation exchange.

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Malvidin was the main anthocyanins in the purified fractions from blueberry pomace.

Food waste is a potential source to replace fresh materials for obtaining functional ingredients. Blueberry pomace contains considerable amounts of anthocyanins. In this study, we investigated ultrasonic-assisted extraction (UAE) of anthocyanins from blueberry pomace. We used a Box-Behnken design (BBD) to screen and optimize the important factors influencing yield. The optimum extraction conditions were a temperature of 40 °C, an ultrasonic power of 400 W and an extraction time of 40 min. The optimum yield was 108.23 mg/100 g DW. In addition, we used a cation column to separate anthocyanins, and optimized the chromatographic conditions of HPLC to analyze and identify the main anthocyanins. Thirteen anthocyanins were found in blueberry pomace, of which Malvidin-3-Galactoside (22.65 %) was the highest. These findings provide a theoretical basis and optimized process parameters for the recovery of high value-added anthocyanins from blueberry pomace with ultrasound-assisted extraction, thus facilitating the comprehensive utilization of blueberry pomace.

Potential health benefits of blueberry and raspberry pomace as functional food ingredients: Dietetic intervention study on healthy women volunteers

The fruit juice industry generates pomace as a valuable by-product especially rich in polyphenols, dietary fibers, vitamins, minerals, and unsaturated fatty acids. In the cookies used in this study, 30% of the gluten-free flour was replaced with dried and ground blueberry and raspberry pomace, rich source of polyphenols, dietary fibers, linoleic and alpha-linolenic acid. In order to examine whether the addition of blueberry and raspberry pomace in cookie formulation can have beneficial effects on certain blood parameters and anthropometric measurements, the designed cookies were tested in 20 healthy, normally fed female subjects, aged 30–50 years (41.35 ± 8.58 years) over four-week dietetic intervention study. Significant changes in the composition of fatty acids serum phospholipids, decrease in LDL-cholesterol level (20.16%), increase in adiponectin level (25.52%) and decrease in ALT and AST values were observed, thus indicating that inclusion of cookies containing blueberry and raspberry dried and ground pomace to usual diet might have positive effects on certain cardiovascular risk factors and liver function indicators.

Optimization the extraction of anthocyanins from blueberry residue by dual-aqueous phase method and cell damage protection study

Blueberry residue is usually discarded as waste, but has a high anthocyanins content. The extraction method of anthocyanins from blueberry residue with ultrasonic assisted dual-aqueous phase system was optimized. In terms of the principle of central group and design (CCD) experimental design, three-factor and five-level response surface analysis was adopted to optimize the extraction conditions with the extraction rate of anthocyanins. The optimum extraction rate of anthocyanin was 12.372 ± 0.078 mg/g. Anthocyanin extract could protect the pBR322 DNA oxidative damage induced by Fenton reagent, increase the superoxide dismutase(SOD) and glutathione peroxidase (GSH-Px) enzyme activities, and decrease the H₂O₂-induced cell apoptosis of human normal liver cell (LO2 cell). The study indicates that the extraction rate of anthocyanin was increased by optimized ultrasonic assisted dual-aqueous phase system. The anthocyanin extract could protect DNA and LO2 cell from oxidative damage.