Evaluation and comparison of antioxidant activity and biochemical compounds in some coloured potato cultivars

Abstract

Potato is an important source of food, and in recent years, new genotypes have emerged on the European market, which particularly differentiate by the colour of tubers. The current study investigated and compared phytochemical properties and antioxidant activity of six potato cultivars: two of those with yellow-fleshed (Carpatin, Brasovean) and four with red and purple-fleshed (Cranberry Red, Mountain Rose, Purple Majesty, and Blue Congo), which were cultivated under the same climatic and soil conditions. The antioxidant activities were evaluated using two antioxidant systems 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The results show that yellow-fleshed cultivars had higher total soluble substance content; red and purple-fleshed cultivars had a higher content of antioxidant compounds. Cv. Blue Congo it was recorded the highest antioxidant capacity in terms of DPPH and ABTS, of 164.17 μmol ascorbic acid (AsA)/100 g FW (fresh weight) and 114.96 μmol AsA/100 g FW, respectively. The highest total phenolic content was registered at cv. Purple Majesty of 63.54 mg gallic acid equivalents/100 g FW. Regarding flavonoids, the highest content was 40.96 mg quercetin equivalents/100 g FW for cv. Blue Congo and anthocyanin at cv. Purple Majesty of 113.19 mg/100 g FW.

Total Phenolic, Total Flavonoids Content and Antioxidant Activity in Fruits of Four Plum (Prunus Domestica L.) Cultivars

“…Positive correlations have been observed when DPPH radical scavenging activities were compared with total phenolic compounds content and total flavonoids content, thus indicating that these compounds are responsible for the antioxidant activity. This positive correlation was also reported for other plant species [9,10].…”

“…The capacity of sample extracts to reduce the radical 2,2-diphenyl-1picrylhydrazyl has been evaluated colorimetrically [10]. 2 mL of 0.075 mM DPPH solution in methanol was mixed with 0.1 mL sample extract and after 20 minutes the absorbance of the remaining DPPH radicals was measured at 517 nm.…”

Nutritional quality and antioxidant activity of currant fruits (Ribes spp.)

“…Reducing sugars (Red sug. %) were extracted in distilled water (1:50 w/V), 60 minutes at 60˚C and assayed colorimetric at 540 nm with 3, 5 dinitrosalicylic acid reagent using glucose as standard [15]. The results were expressed in %.…”

“…Glucose (Glu %) content was assayed at 500 nm by glucose oxidase/peroxidase method [15]. Glucose oxidase catalyzes the oxidation of glucose by oxygen in the air to gluconolactone and hydrogen peroxide.…”

Total Phenolic, Total Flavonoids Content and Antioxidant Activity in Fruits of Four Plum (Prunus Domestica L.) Cultivars

“…Total anthocyanin content (TA) was measured by the pH differential method [10] Sample extracts were diluted with potassium chloride and with sodium acetate buffers (pH 1.0 and 4.5, respectively) and after an equilibration period, absorbance of each solution was measured at 520 and 700 nm. The absorbance value was calculated as A= [(A520 -A700) pH 1.0 -(A520 -A700) pH 4.5].…”