Bioactive properties and chemical composition of six walnut (Juglans regia L.) cultivars

Abstract

The chemical composition, antioxidant potential and antimicrobial activity were studied in six walnuts (Juglans regia L.) cultivars (cv. Franquette, Lara, Marbot, Mayette, Mellanaise and Parisienne) produced in Portugal. Concerning their chemical composition the main constituent of fruits was fat ranging from 78.83% to 82.14%, being the nutritional value around 720 kcal per 100 g of fruits. Linoleic acid was the major fatty acid reaching the maximum value of 60.30% (cv. Lara) followed by oleic, linolenic and palmitic acids. The aqueous extracts of walnut cultivars were investigated by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and b-carotene linoleate model system. All the walnut extracts exhibited antioxidant capacity in a concentration-dependent manner being the lowest EC 50 values obtained with extracts of cv. Parisienne. Their antimicrobial capacity was also checked against gram positive (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus) and gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans), revealing activity against the different tested microorganisms.

Proximate composition, minerals and fatty acid composition of Juglans Regia L. genotypes and cultivars grown in Turkey

“…The major fatty acids in the Turkish samples were linoleic (C18:2), followed by oleic It was the genotype having the highest value of oleic acid. These data were in general agreement with those of earlier reports (Amaral et al 2003;Li et al 2007;Venkatachalam and Sathe 2006;Pereira et al 2008). The PUFA/MUFA ratio varied from 1.54 to 3.97.…”

“…Indeed, different values of temperature, rainfall and light can influence the chemical composition of fruits. The energy values determined in the current study ranged from 682 to 728 kcal and were similar to the values reported by Amaral et al (2003) and Pereira et al (2008). The mineral composition of the genotypes and cultivars studied is shown in Table 2.…”

“…The chemical compositions of the cultivars and genotypes are shown in Pereira et al (2008) have evaluated the chemical composition of six walnut cultivars in Portugal. They found that the total oil content of the nuts ranged from 68.83 to 72.14 %.…”

“…Immediately after grinding, the walnuts were extracted for 6 h with hexane using a Soxhlet apparatus (Paquat and Houtfenne 1987). Energy was expressed in kilocalories, using the following formula: Energy kcal = 4 x (protein g + carbohydrate g) + 9 x (lipid g) (Pereira et al, 2008). The protein, carbohydrate and total oil content of fruits were calculated on a dry weight basis.…”

Chemical composition, molecular weight distribution, secondary structure and effect of NaCl on functional properties of walnut (Juglans regia L) protein isolates and concentrates

“…As a by-product of oil production, walnut protein products are therefore being considered as an additional source of plant protein for use in human food products. Walnuts nutrient composition has been investigated by several investigators (Sze-Tao and Sathe 2000b; Amaral et al 2003;Savage 2001;Pereira et al 2008). However, chemical composition and functional properties of walnut protein isolates and concentrates have not been investigated.…”