Comparing pH differential and methanol‐based methods for anthocyanin assessments of strawberries

• Published in: Food science & nutrition Vol. 10; no. 7; pp. 2123 - 2131
• Main Authors: Taghavi, Toktam, Patel, Hiral, Rafie, Reza
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.07.2022; John Wiley and Sons Inc
• Subjects: Anthocyanins; Carbon; Cardiovascular disease; Chloroform; chloroform fraction; Chromatography; Flavonoids; Flowers; Fruits; Impurities; Magnesium oxide; Methanol; methanol extract; method development; Methods; organic solvent; Organic solvents; Original; Original Research; pH effects; Pigments; Plant tissues; Solvents; Spectrophotometry; Strawberries; method development; chloroform fraction; pigments; flavonoids; methanol extract; organic solvent
• ISSN: 2048-7177; 2048-7177
• DOI: 10.1002/fsn3.2065

Anthocyanins are a group of water‐soluble polyphenolic pigments found primarily in flowers, vegetables, and fruits. These pigments play critical roles in plant and human health. Spectrophotometric methods are a simple and inexpensive way to quantify anthocyanins in plant tissues. Two main spectrophotometric methods have been developed, organic solvent‐based, and pH differential methods. Both of these methods are subject to interference from light‐absorbing impurities and need to be optimized for different matrixes of different plant materials. Eight methods have been tested in this experiment to quantify anthocyanins in strawberry fruits. Six organic solvent‐based methods tested methanol, chloroform‐methanol, and MgO in different ratios. The other two methods were pH differential method and a combination of organic solvent‐based and pH differential method. Two methods used organic solvents (methanol and chloroform‐methanol) were the best in extracting anthocyanin from strawberry fruits. Adding MgO increased the pH of the extract and was less efficient in anthocyanin extraction. All other methods had lower anthocyanin yield compared with methanol and chloroform‐methanol methods and are not recommended for strawberry fruit anthocyanin extraction. Two organic solvents, methanol and chloroform‐methanol, were the best in extracting anthocyanin from strawberry fruits. MgO decreased anthocyanin yield. All other methods had lower anthocyanin yield compared with methanol and chloroform‐methanol methods.