JOURNAL OF FOOD AND NUTRITION RESEARCH, cilt.59, sa.4, ss.352-360, 2020 (SCI-Expanded)
The objective of the present work was to study total oil, fatty acid, tocopherol, total phenol, phenolic compound content and antioxidant activity of unique walnut genotypes with red-coloured seed coat. Seven red walnut genotypes plus 'Chandler' as a standard cultivar were selected as plant materials for the work. The total oil content of the genotypes ranged from 409.44 g.kg(-1) to 567.87 g.kg(-1). Fatty acids from walnut kernel oil were mostly composed of myristic, myristoleic, palmitic, oleic, linoleic and linolenic acids, linoleic acid being dominant. Tocopherol contents varied among the genotypes - alpha-tocopherol from 1.18 mg.kg(-1) to 15.25 mg.kg(-1), beta- + gamma-tocopherol from 154.76 mg.kg(-1) to 331.27 mg.kg(-1) and delta-tocopherol from 3.24 mg.kg(-1) to 45.86 mg.kg(-1). Total phenolics content ranged from 118.12 mg.kg(-1) to 169.6 mg.kg(-1) (expressed as gallic acid equivalent). Antioxidant capacity was found between 68.2 % and 69.8 %. Contents of phenolics, namely, gallic acid, catechin, caffeic acid, syringic acid, p-coumaric acid, rutin trihydrate, ellagic acid, quercetin, naringin and juglone varied greatly among genotypes. The results indicate that red walnut variants are a great source of oils, fatty acids, tocopherols and phenolics, having good antioxidant potential as well.