Chemical Composition and Antioxidant Activity of Walnut Pollen Samples

Abstract

Chemical composition of pollen is highly varied depending on the plant species from which it comes and has been the subject of numerous comparative studies. The aim of this study was to determine chemical composition and antioxidant activity of walnut pollen samples and compare them with those of bee pollen. Total phenols content, total flavonoids content, antioxidant activity and mineral composition were studied using walnut pollen samples from three walnut genotypes cultivated in Romania. Total phenols content was determined by colorimetric assay and their amount varied between 10.8 and 17.64 mgGAE/g per genotype. Determination of flavonoids was done by aluminium nitrate colorimetric method and total flavonoid contents in walnut pollen ranged from 7.32 to 7.95 mgQE/g. The antioxidant capacity of pollen extracts was assessed through the scavenging effects on DPPH and a concentration-dependent genotype, and it varied between 13.78 and 15.04 mg Trolox/g. In terms of mineral composition, walnut pollen appears to be a good source of potassium (859.14 mg/100 g), magnesium (263.77 mg/100 g), calcium (71.72 mg/100 g), iron (27.19 mg/100 g), sodium (10.52 mg/100 g), zinc (5.69 mg/100 g), manganese (3.98 mg/100 g), copper (1.28 mg/100 g), chromium (0.39 mg/100 g) and selenium (0.036 mg/100 g). The results obtained indicate that walnut pollen is an important source of total phenols showing antioxidant properties and mineral composition that could be beneficial to human health.

Phytochemical Screening, Antioxidant and Antibacterial Activities of Pollen Extracts from Micromeria fruticosa, Achillea fragrantissima, and Phoenix dactylifera

“…Regarding the flavone, flavonol and total phenolic content, the pollen extract of Micromeria fruticosa contains significant amounts followed by Achillea fragrantissima and Phoenix dactylifera . These results agree with many studies that have identified the phenolic and flavonoid compounds in pollen [ 40 , 41 ], and they have been shown to have potent antioxidant properties [ 41 , 42 ]. Their antioxidant capacities support the human body’s battle against diseases by absorbing free radicals and chelating metal ions that could catalyze the production of reactive oxygen species (ROS), which facilitates lipid peroxidation [ 36 ].…”

Antioxidant and Antibacterial Effects of Pollen Extracts on Human Multidrug-Resistant Pathogenic Bacteria

“…Punica granatum pollen extract had the highest value (246.07 ± 2.62 mg GAE/g), followed by Quercus ilex pollen extract (146.37 ± 1.95 mg GAE/g). However, the lowest polyphenol content was recorded in the Centaurium erythraea pollen extract (21.39 ± 0.31 mg GAE/g), which is higher than that reported by Cosmulescu et al [28] for three Romanian walnut pollen samples ranging between 10.8 and 17.64 mg GAE/g. Avşar et al found that the phenolic content of Castanea sativa pollens ranged between 64.02 ± 0.26 and 103.8 ± 6.72 mg GAE/g; these results were higher than those obtained by Centaurium erythraea, Coriandrum sativum, Ruta graveolens, and Citrus aurantium pollen extracts and lower than those found in Quercus ilex and Punica granatum pollen extracts [8].…”

“…For flavones/flavonols, Quercus ilex pollen extract presented the highest content (40 ± 0.26 mg QE/g) followed by the Punica granatum pollen extract (32 ± 0.9 mgQE/g) and Ruta graveolens pollen extract (9.78 ± 1.17 mg QE/g), whereas Citrus aurantium, Centaurium erythraea, and Coriandrum sativum pollen extracts expressed the lowest contents (6.11 ± 0.03 mg QE/g, 5.56 ± 0.13 mgQE/g, and 5.18 ± 0.26 mgQE/g, respectively). e flavone/flavonol content average of analyzed samples (86.42 ± 83.05 mg QE/ g) was higher than that found in three pollen samples harvested from different areas of Romania (7.98 ± 0.26 mg QE/g) [28].…”

Evaluation of antioxidant activity of bee products of different bee races in Turkey

“…LeBlanc et al [43] reported that the total flavonoid values of the bee pollen of the Sonoran Desert ranged from 5.48 to 2.66 mg QUE/g. In other study, total flavonoid contents in pollen ranged from 7.32 to 7.95 mg QUE/g and DPPH scavenging activity was found to be between 13.87 and 15.04 mg Trolox/g [44]. It was seen that, due to the diversity of bee pollen and supply from different regions, the polyphenol content, flavonoid content, and antioxidant activity could change from one region to another.…”