Emerging Non-Thermal Technologies for the Extraction of Grape Anthocyanins

Abstract

Anthocyanins are flavonoid pigments broadly distributed in plants with great potential to be used as food colorants due to their range of colors, innocuous nature, and positive impact on human health. However, these molecules are unstable and affected by pH changes, oxidation and high temperatures, making it very important to extract them using gentle non-thermal technologies. The use of emerging non-thermal techniques such as High Hydrostatic Pressure (HHP), Ultra High Pressure Homogenization (UHPH), Pulsed Electric Fields (PEFs), Ultrasound (US), irradiation, and Pulsed Light (PL) is currently increasing for many applications in food technology. This article reviews their application, features, advantages and drawbacks in the extraction of anthocyanins from grapes. It shows how extraction can be significantly increased with many of these techniques, while decreasing extraction times and maintaining antioxidant capacity.

Up-To-Date Analysis of the Extraction Methods for Anthocyanins: Principles of the Techniques, Optimization, Technical Progress, and Industrial Application

“…The UAE technique is based on an ultrasound force that is able to break the cell wall due to that cavitation phenomenon that occurs in the tissue of the sample [ 10 , 40 ]. Figure 2 shows a schematic representation of ultrasound-assisted extraction (UAE) equipment, with an explanation about the cavitation process that occurs as a consequence of the ultrasound force.…”

“…UAE is widely used in the extraction of bioactive compounds in different natural matrices [ 10 , 21 , 29 , 41 , 42 , 43 , 44 , 45 ]. However, to obtain the maximum yield of anthocyanins by UAE, it is necessary to optimize the extraction conditions.…”

“…Consequently, this technique is not only ideal because it is faster, but it also consumes less solvent, is more environmentally friendly, and has a lower cost with higher yields compared to conventional extraction techniques. In addition, this technique is simple ( Figure 2 ) and does not require complex maintenance [ 10 , 21 ]. At the industrial scale, UAS is a promising technique to displace conventional techniques, due to less extraction times, higher extraction yields, and lower operating temperatures.…”

“…Demirdöven et al [37] optimized the extraction conditions, time, temperature and solvent composition (percentage of ethanol) to maximize the efficiency of anthocyanin extraction from red cabbage by UAE (Table 1). UAE is widely used in the extraction of bioactive compounds in different natural matrices [10,21,29,[41][42][43][44][45]. However, to obtain the maximum yield of anthocyanins by UAE, it is necessary to optimize the extraction conditions.…”

“…Some of these compounds belong to the group of anthocyanins, which are not only antioxidant compounds, but are also natural colorants (with aglycones of anthocyanins being the most common plant pigments). The properties of anthocyanins have been extensively studied in the literature [2][3][4][5][6][7][8][9][10]. These properties are directly related to their chemical structures.…”