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Phenolic content, antioxidant capacity and quality of dried chokeberry products (Aronia melanocarpa) from Croatian market

Black chokeberries (Aronia melanocarpa) are species of the fruit which are considered to be one of the most valuable sources of phenolic substances and the research in the field of the fruit utilization as a food supplement is more than topical. The aim of our measurment was to compare the physicochemical properties, the content of phenolics and antioxidant properties of different chokeberry products (Aronia melanocarpa) present on the Croatian market.The physicochemical analyses included soluble solids, pH, total solids and total titratable acidity. The total phenolic content (TPC), nonflavonoid content (TN) and flavonoid content (TF) were determined spectrophotometrically according to the Folin–Ciocalteau procedure ; while total anthocyanin content (TA) was determined using pH- differential method. Antioxidant properties of products were measured by 2 tests: total antioxidant capacity (TAC) using DPPH free radical assay and ferric reducing antioxidant power (RP) using FRAP assay. The highest pH value were observed in dried berries with the value of 4, 15 and the lowest in the chokeberry capsules with the value of 3, 71. Among the researched products, chokeberry capsules had highest total titratable acidity (3, 38 % malic acid), followed by chokeberry powders, teas and dried berries, respectively. Highest contents of total solids and soluble solids had capsules (93, 78 % ; 57, 81 °Brix) while dried berries had lowest contents (83, 31 % and 23, 21°Brix). Total phenolic content (TPC) varied from 2210, 36 mg/100 g DM to 4902, 02 g/100 g DM in dried berries and capsules. Chokeberry capsules also contained highest amounts of TN (2176, 24 mg/100 g DM) and TA (2232, 98 mg/100 g DM) while highest TF had powders (2825, 47 mg/100 g DM). Total antioxidant capacity ranged from 69, 71 mmol TE/100 g DM in capsules to 187, 41 mmol TE/100 g DM in dried berries. Reducing power varied from 19, 44 mmol Fe2+/100 g DM to 63, 09 mmol Fe2+/100 g DM in dried berries and capsules.The study indicated that there are significant differences (p<0, 05) in physicochemical properties, total phenols and anthocyanin content as well in the reducing power between chokeberry powders, capsules and teas availble on Croatian market.

antioxidant capacity ; chokeberry ; phenols ; products ; reducing power

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