Green extraction of anthocyanin from red cabbage waste using acid whey as a promising bio-based solvent

Abstract

The use of acid whey as a biological-based solvent may be an innovative and sustainable strategy to add value to agro-industrial by-products. This study assessed acid whey as a solvent for extracting anthocyanins from discarded red cabbage leaves. Methods such as Heating and Stirring Extraction (HSE), Ultrasound-Assisted Extraction (UAE), and Pressurized Liquid Extraction (PLE) were compared using acid whey or acidified ethanol as solvents. The yield of anthocyanin extract from acid whey is approximately 7 % lower compared to that obtained from acidified ethanol. All extracts exhibited in vitro antioxidant activity. Anthocyanin-rich extracts from red cabbage leaves revealed the predominant presence of cyanidin-3-O-(feruloyl)-sophoroside-5-O-glucoside (949 m/z). No cytotoxic effects were observed in the tested extracts, underscoring their safety and potential for industrial applications. Furthermore, incorporating powdered extracts into marshmallows yielded promising results as a natural colorant, emphasizing their versatility. These findings underscore acid whey role as a sustainable biobased solvent for extracting anthocyanins from red cabbage waste.

Industrial relevance

The use of acid whey as a solvent for extracting anthocyanins from purple cabbage leaves is a valuable alternative in the agroindustry. This practice adds value to by-products and promotes sustainability. Emerging technologies, such as ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE), enhance the efficiency of this process. Analysis shows that acid whey is efficient and environmentally friendly, yielding extracts with antioxidant properties. These extracts can also serve as natural colorants, meeting the demand for natural ingredients. Thus, acid whey enhances sustainability in agroindustrial production.