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B14-P: HPLC ANALYSIS OF PHENOLICS OF PARSNIP ROOTS OF DIFFERENT SIZE

N. Nikolić (1), Z. Todorović (1), M. Sakač (2)

1 Faculty of Technology, University of Niš, Bulevar oslobodjenja 124, 16 000 Leskovac, Serbia

2 Institute for Food Technology, Bulevar Cara Lazara 1, 21 000 Novi Sad, Serbia

Phenolic compounds have free radical scavenging abilities [1], antimutagenic and anticancerogenic activities and ability to modify the gene expression [2]. Many studies confirm the connection between the dietary intake of phenolics, especially flavonoids, and the reduction of cardiovascular and carcinogenic risk [3]. These are reasons why there is increasing interest for phenolics compounds in food, today. In this paper content and composition of phenolics of three different size parsnip roots were examined and based on statistical analysis similarity among samples was determined. Parsnip roots, cultivar Long white, grown in Serbia, with the same period of development and size 55±5 g (P1), 100±10 g (P2) and 350±30 g (P3) were used. The roots were dried at room temperature and milled to average particle size of  0.5 mm. Plant extracts were prepared by using 80% (v/v) ethanol and total phenolics content was determined based on a standard curve with chlorogenic acid (in the range from 50 to 1.50 mmol), using equation: TPC = (A-0.1083/4.89 x 10-4 (mmol chlorogenic acid/l).

HPLC analyses were performed on an Agilent 1100 Series HPLC system consisted of micro vacuum degasser, binary pump, thermostatted column compartment and variable wavelength detector. An original Viet et al. (1995) method [4] was used. Column was Agilent Eclipse XDB-C18 4.6 mm IDx 150 mm (5 μm) 80 Å, elution profile: A=0,15 % phosphoric acid in H2O-MeOH 77:23 (pH=2); B=MeOH, isocratic: 0-3.6 min, 100% A; gradient: 3.6 min, 100% A-linear-24,0 min, 80.5% A-isocratic-30 min, linear-60 min; 51.8% A-linear-67.2 min, 100% B, flow rate was 1.0 ml min-1 and the dosing volume was 20 µl. Spectrophotometric detection in the UV region at 350 nm was used. The phenolics content was in range 27.34 (P1) to 31.19 (P3) mmol chlorogenic acid per g of absolute dried plant material. By HPLC analysis 21 compounds were found, among 17 were identified. In total sum, the quercetins were in content from 5.95 to 9.38, kaempferols, from 7.51 to 8.52, genkwanins, from 0.46 to 1.53 and apigenin 1.11 to 3.23%. Unfortunately, compound with retention time of 11.7 min, which was in the highest content of 1.59 to 28.80%, was non-identified by used method. Probably, it is compound from group of furanocumarins or phenolics acid, as this compounds are predominant phenolics in carrots [5], where parsnip belongs. Based on total phenolics, quercetins, kaempferols, genkwanins, apigenin and non-identified compound content (the number of variables was six), cluster analysis and the Euclidean linkages distances results showed higher similarity between P2 and P3 sample, i.e. parsnip roots with greater weight: samples P2 and P3 were joined at linkage distance of 19.9, while sample P1 was joined with P1 and P2 at linkage distance of 24.1.

References

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