Total Anthocyanin Content of Strawberry and the Profile Changes by Extraction Methods and Sample Processing

Abstract

Anthocyanins are the primarily pigments in many flowers, vegetables, and fruits and play a critical role in human and plant health. They are polyphenolic pigments that are soluble in water and usually quantified by spectrophotometric methods. The two main methods that quantify anthocyanins are pH differential and organic solvent-based methods. Our hypothesis was that these methods extract different anthocyanin profiles. Therefore, this experiment was designed to identify anthocyanin profiles that are extracted by pH differential and organic solvent-based methods and observe their total anthocyanin content from strawberries. Six methods were tested in this experiment to quantify and profile anthocyanins in strawberry fruits by spectrophotometry and Ultra High Performance Liquid Chromatography (UHPLC) respectively. Four methods used organic solvents (methanol, and chloroform-methanol) in different combinations. The next two methods were pH differential and a combination of organic solvent and the pH differential method. The results suggest that acidified chloroform-methanol extracted the highest anthocyanin content compared to water-based solvents. Methanol-water based solvents also performed better than methanol alone, because both methanol and water may extract different profiles of anthocyanins. Water-based extracts had the greatest absorbance at a lower wavelength (498 nm), followed by methanol (508 nm), and chloroform (530 nm). Chloroform-methanol solvent with higher pH (3.0) extracted pelargonidin as the main anthocyanin, while methanol and water-based solvents (with lower pH 1.0–2.0) extracted delphinidin as their main anthocyanin as identified by UHPLC. Therefore, chloroform-methanol and methanol-water solvents were the best solvents for extracting anthocyanins from strawberries. Also, freeze-dried strawberries had higher anthocyanin contents compared to fresh or frozen samples.

Investigation of the effects of bovine collagen peptides and mixed berries on rheological properties and biological activity of egg white-based beverage via central composite design

“…The same order of magnitudes TA were reported in fresh, frozen, and frozen-dried strawberries using a similar method to Taghavi et al ( 62 ). It seems that anthocyanin and phenolic compounds stay stable during cold storage of fruit yogurts due to the bounds between proteins and phenolic compounds ( 75 ), the intermolecular actions between bovine collagen, egg white proteins, and anthocyanins haven't been deeply analyzed yet.…”

“…In this method, the anthocyanin content of egg white-based beverage samples was measured by the pH differential method presented by Lee et al ( 61 ) and Taghavi et al ( 62 ). One mL of the egg white-based beverage samples was mixed thoroughly with 19 mL buffer pH 1.0 (0.025 M potassium chloride) and 1 mL of the egg white-based beverage samples was mixed thoroughly with 19 mL buffer pH 4.5 (0.4 M sodium acetate buffer).…”

Enzymatic acylation of cyanidin-3-O-glucoside in raspberry anthocyanins for intelligent packaging: Improvement of stability, lipophilicity and functional properties

“…The thermostability of ACNs and acylated ACNs were determined by incubation of ACNs and acylated ACNs solutions at 65, 80, and 90 °C, respectively, using a water bath and monitoring the change of anthocyanins concentration using the pH-differential method over time ( Taghavi et al, 2022 ). To evaluate light stability, solutions of anthocyanin (20 mL) in screw-cap glass vial were placed under the incandescent light bulb (40 w) and ultraviolet illumination (253.7 nm/185 nm, ≥ 214 uw/cm 2 ) (Jiangyin Instrument Co., Ltd., Jiangyin, China) at 20 °C, with change in anthocyanin concentration over time determined using pH differential method.…”

Metabolome and Transcriptome Reveal Chlorophyll, Carotenoid, and Anthocyanin Jointly Regulate the Color Formation of Triadica sebifera

“…After that, the mixture was centrifuged at 15,000 Â g for 10 minutes and the absorbance of the supernatant was taken at 530 nm and 657 nm. The relative content of anthocyanins was calculated by the formula:Q = OD 530 Â (OD 657 /4) (Taghavi et al 2022).…”