Statistical optimization of an RP‐HPLC method for the determination of selected flavonoids in berry juices and evaluation of their antioxidant activities

Abstract

An isocratic RP-HPLC method for the separation and identification of selected flavonoids (quercetin, rutin, luteolin-7-O-glucoside, kaempferol and kaempferol-3-O-glucoside) in commercial berry juices (blackcurrant, blueberry, red raspberry and cherry) was developed with the aid of central composite design and response surface methodology. The optimal separation conditions were a mobile phase of 85:15 (% v/v) water-acetonitrile, pH 2.8 (adjusted with formic acid), flow rate 0.5 mL min and column temperature 35°C. The obtained levels of bioflavonoids (mg per 100 mL of juice) were as follows: for quercetin, ca. 0.21-5.12; for kaempferol, ca. 0.05-1.2; for rutin, ca. 0.4-6.5; for luteolin-7-O-glucoside, ca. 5.6-10.2; and for kaempferol-3-O-glucoside, ca. 0.02-0.12. These are considerably lower than the values in fresh fruits. Total phenolic, flavonoid and anthocyanin contents were determined spectrophotometrically. Total flavonoid content varied as follows: blackcurrant > blueberry > red raspberry > cherry. The antioxidant activity of juice extracts (DPPH and ABTS methods) expressed as IC values varied from 8.56 to 14.05 mg L . These values are ~2.5-3 times lower than quercetin, ascorbic acid and Trolox®, but compared with rutin and butylhydroxytoluene, berries show similar or better antioxidant activity by both the DPPH and ABTS methods.

Molecular Mechanism and Health Role of Functional Ingredients in Blueberry for Chronic Disease in Human Beings

“…The concentrations of bioflavonoids in commercial berry juices (blackcurrant blueberry, red raspberry, and cherry) (mg/100 g of juice) are as follows. Luteolin-7- O -glucoside (5.6–10.2) > rutin (0.4–6.5) > quercetin (0.21–5.12) > kaempferol (0.05–1.2) > kaempferol-3- O -glucoside (0.02–0.12), however blackcurrant > blueberry > red raspberry > cherry for total flavonoids; the antioxidant activity of juice extracts is expressed as IC50 values from 8.56 to 14.05 mg/kg [ 6 ]. The total anthocyanin and polyphenol content in blueberry juice was higher, which also has higher antioxidant activity, but cranberry juice had a greater capacity than blueberry juice as an α-glucosidase inhibitor [ 7 ].…”

Development and Validation of an HPLC-DAD Method for the Simultaneous Analysis of Phenolic Compounds

“…Assessment of accuracy through the recovery method by several studies also attained values that are within the 100 ± 5 % range. Ciric et al [48], Tang et al [49], and Seal et al [26] achieved percent recovery values ranging from 98.57 -100.27%, 95.00% -104%, and 98.13 -99.20%, respectively.…”

Cherries and Blueberries-Based Beverages: Functional Foods with Antidiabetic and Immune Booster Properties

“…Concerning non-colored phenolic compounds, the most found in tart cherry juices include 5-caffeoylquinic acid (28.30–995.0 mg/L), 3-coumarolyquinic acid (91.0–555.0 mg/L), 3-caffeoylquinic acid (82.0–183.0 mg/L), ferulic acid (1.14–1.27 mg/L), quercetin aglycone (184.0–739.0 mg/L), quercetin 3- O -rutinoside (4.0–53.80 mg/L), and (−)-epicatechin (13.60–369.0 mg/L) [ 56 , 87 , 88 , 100 , 109 ]. On the other hand, sweet cherry juices are mainly composed of 3-caffeoylquinic acid (24.77–37.78 mg/L), syringic acid (6.64–14.46 mg/L), gallic acid (0.0–6.55 mg/L), and quercetin 3- O -rutinoside (0.0–4.74 mg/L) [ 97 , 103 ]. Finally, blueberry juices are richer in luteolin 7- O -glucoside (ca., 102 mg/L) and quercetin 3- O -rutinoside (ca., 65 mg/L) [ 45 , 103 , 107 ].…”

“…On the other hand, sweet cherry juices are mainly composed of 3-caffeoylquinic acid (24.77–37.78 mg/L), syringic acid (6.64–14.46 mg/L), gallic acid (0.0–6.55 mg/L), and quercetin 3- O -rutinoside (0.0–4.74 mg/L) [ 97 , 103 ]. Finally, blueberry juices are richer in luteolin 7- O -glucoside (ca., 102 mg/L) and quercetin 3- O -rutinoside (ca., 65 mg/L) [ 45 , 103 , 107 ]. Additionally, they present residual amounts of ρ -hydroxybenzoic acid, vanillic acid, 5-caffeoylquinic acid, caffeic acid, syringic acid, ferulic acid, and quercetin 3- O -glucoside [ 95 ].…”