G Gallic Acid Equivalents Research Articles

Determination of total phenolic content, total flavonoid content and FRAP in culinary herbs in relation to harvest time

In this study there were evaluated total phenolic and flavonoid contents, and ferric reducing antioxidant power (FRAP)of 3 herbs species, that are commonly used in fresh stage (summer savory –Satureja hortensisL., marjoram –Majorana hortensisM. and thyme –Thymus vulgarisL.) in dependence on time of harvest. The total flavonoid content ranged from 2.36 to 4.10 g of catechin equivalents (CE).100g−1of dry weight (dw) of plant material. The highest average total flavonoids content was ascertained in aerial part of summer savory colected in first harvest (4.10 g CE.100g−1dw) and the lowest in aerial part of summer savory collected in third harvest (2.36 g CE.100g−1dw). The highest total flavonoid content was measured by all tested species in plant material harvested in first time of harvest. The highest total phenolic content was estimated in plant material of marjoram harvested in the second time of harvest (6.74 g gallic acid equivalents (GAE).100g−1dw) and the lowest in aerial part of summer savory harvested in the third time of harvest (4.16 g GAE .100g−1dw). Ferric reducing antioxidant power (FRAP) ranged from 1,13 (summer savory, harvest No. 3) to 1.91 g GAE .100g−1dw (thyme, harvest No. 1). The best results of total flavonoid content, total phenolic content and FRAP were obtained by marjoram. Among harvest times there were the highest contents of measured compound mainly by the samples collected in the first time of harvest.

Effects of Korean ginseng (<i>Panax ginseng</i> C.A. Meyer) root extract on egg production performance and egg quality of laying hens

This study was conducted to determine the effect of Korean ginseng ( Panax ginseng C.A. Meyer) root extract (PGRE) on egg production and egg quality characteristics of hens at the beginning of their laying period (20 weeks old). Four groups of commercial hens (Atak-S; Turkish native hybrid) were fed with diets containing 0 mg, 50 mg, 100 mg and 150 mg PGRE/kg. Experimental results indicated that dietary PGRE had no effect on feed intake, feed efficiency, egg mass (EM) or egg production parameters. Over 12 weeks, hen-day egg production (HDP) of the groups was 73.5%, 74.8%, 69.2% and 79.0%, respectively. The effect of different levels of PGRE on egg weight, shape index (SI), specific gravity, shell thickness, Haugh Unit (HU), yolk index (YI) and albumen index (AI) was not statistically significant during the entire experiment. Egg yolk colour was conspicuously lower in the 100 mg and 150 mg PGRE/kg groups than in the control. The L*, a* and b*, hue (H) and chroma (C*) values for eggshell colour were not significantly different among the groups, except for the colour difference (ΔE*, (L 2 +a 2 +b 2 ) ½ ), where values in PGRE groups were higher than in the control group. The trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and total phenolics concentration of PGRE were 598 ± 1.841 mmol trolox/kg, 15.45 ± 0.457 mmol TEAC/kg and 1.02 ± 0.03 g gallic acid equivalents (GAE)/kg, respectively. Serum glucose, cholesterol and triglyceride concentration were similar in the PGRE supplemented groups and the control. In conclusion, the dietary supplementation with PGRE did not affect the productivity performance traits and egg quality of hens at the beginning of the laying period. Keywords: Herb extract, egg yield, egg traits, egg shell colour, biochemical parameters, antioxidant activity

Effects of co-fermentation by Saccharomyces cerevisiae and Issatchenkia orientalis on sea buckthorn juice

This work relates to the development of a co-fermented product of sea buckthorn (Hippophae rhamnoides L.) with Saccharomyces cerevisiae and Issatchenkia orientalis. Besides malic acid degradation, the parameters of present production technology were also standardized with emphasis on the retainability of total phenolic content (TPC) of sea buckthorn juice. The effect of co-fermentation on physico-chemical characteristics, organic acids, flavonoids, TPC and antioxidant activities was studied. The high-performance liquid chromatography (HPLC) analysis showed 55% reduction in malic acid content after the co-fermentation of sea buckthorn juice. The TPC of sea buckthorn product was 2.18 g gallic acid equivalent (GAE)/l. The estimated scavenging effect on 2,2-diphenyl-1-picrylhydrazyl free radicals was 2.63 Trolox equivalent (TE) mmol/l. Ferric-reducing antioxidant power and 2,2′-azino-bis(3-ethylbenz-thiazoline-6-sulphonic acid) assays also showed that sea buckthorn product was on a par with commercial wines (Cabernet Shiraz and Beaujolais). We conclude that the process of co-fermentation resulted in a significant antioxidant potential of sea buckthorn product.

Chemical composition and in vitro evaluation of the antioxidant and antimicrobial activities of Eucalyptus gillii essential oil and extracts.

In this study, essential oil and various extracts (hexane, petroleum ether, acetone, ethanol, methanol and water) of Eucalyptus gilii were screened for their chemical composition, antimicrobial and antioxidant activities. The essential oil chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID), respectively. Thirty four compounds were identified, corresponding to 99.5% of the total essential oil. Tannins [104.9–251.3 g catechin equivalent (CE)/Kg dry mass], flavonoids [3.3–34.3 g quercetin equivalent (QE)/Kg dry mass], phenolics [4.7–216.6 g gallic acid equivalent (GAE)/Kg dry mass] and anthocyannins [1.2–45.3 mg cyanidin-3-glucoside equivalent (C3GE)/Kg dry mass] of various extracts were investigated. Free radical scavenging capacity of all samples was determinedt. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, the IC50 of essential oil was 163.5 ± 10.7 mg/L and in the 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS) assay, it was 94.7 ± 7.1 mg/L. Among the various extracts, the water extract showed the best result (IC50 = 11.4 ± 0.6 mg/L) in the DPPH assay which was comparable to vitamin C (IC50 = 4.4 ± 0.2 mg/L). The antimicrobial activities were evaluated against different bacterial and fungal strains. Gram positive bacteria were found to be more sensitive to the essential oil and extracts than Gram negative ones. Anthocyanins seem to have a major effect on the growth of Bacillus subtilis (R2 = 0.79). A significant antifungal activity was observed against the yeast and fungi. Correlations between chemical composition and antioxidant activities were studied and R2 values were about 0.96 for the effect of phenolics on the DPPH assay.

Antioxidant, anti-inflammatory activity, and phytochemical constituents of ficus (Ficus amplissima Smith) bark

In the present investigation, phenolics (36.6 g gallic acid equivalents (GAE)/100 g extract), tannin (21.6 g GAE/100 g extract), and flavonoid content (67.5 g rutin equivalents/100 g extract) were found to be highest in acetone extract. Ficus (Ficus amplissima) acetone extract showed maximum antioxidant activity in phosphomolybdenum (958.8 mg ascorbic acid equivalents/g extract), DPPH (1.6 μg/mL), ferric reducing antioxidant power (2,993 mmol Fe (II)/g extract), and metal chelating (39.7 mg EDTA equivalents/g extract) assays. In anti-inflammatory study, 400 mg/kg acetone extract showed maximum reduction in the paw volume compare to indomethacin. GC-MS analysis indicated that bark contain rich source of non-polar compounds like Lup-20(29)-en-3-yl acetate (33.04%). Hence, Ficus can be valuable source for antioxidant and anti-inflammatory and seemed to be applicable in medicine.

Evaluation of a Subset of the Solanum lycopersicum var. cerasiforme Core Collection for Horticultural Quality and Fruit Phenolic Content

One hundred S. l. var. cerasiforme (Dunal) accessions from the ‘Tanksley’ designated core collection were evaluated for horticultural quality under greenhouse conditions. Fourteen selected accessions were grown under field conditions in a replicated trial to evaluate the fruit for phenolic content. Total fruit phenolics ranged from 44 to 82 mg/100 g gallic acid equivalents (GAE) fresh weight (FW) as measured by Folin-Ciocalteau assay (F-C), and 12 to 108 mg/100 g FW as measured by high-performance liquid chromatography (HPLC). Five accessions (LA1712, LA1455, LA2633, LA1668, and LA2632) had significantly higher total phenolics (F-C) than cultivars (P ≤ 0.05). These five accessions also possessed interesting phenolics profiles, including high levels of caffeoylquinic acids (LA1620, LA1455, and LA2633) and rutin (LA2633).

Extraction of antioxidants from eucalyptus (Eucalyptus globulus) bark

The extraction of phenolic compounds from eucalyptus (Eucalyptus globulus) bark was examined with the aim of analyzing the potential of the extracts as natural antioxidants. Experiments were planned according to a 23 factorial design to analyze the influence of temperature and Na2SO3 and NaOH concentrations in aqueous solutions on extraction yield, extract total phenols content, ferric reducing antioxidant power (FRAP), and number- and weight-average molecular weights. Extract total phenols content and FRAP antioxidant activity in the ranges 0.91–2.58 g gallic acid equivalent (GAE)/100 g oven-dried bark and 4.70–11.96 mmol ascorbic acid equivalent (AAE)/100 g oven-dried bark, respectively, demonstrated the potential of eucalyptus bark as a source of antioxidant compounds. Extraction at the highest temperature (100°C), the lowest Na2SO3 concentration (1.5% on oven-dried bark), and without NaOH provided the highest extract total phenols content and FRAP antioxidant activity. Those eucalyptus bark extracts with lower molecular weight showed higher antioxidant activity. Matrix-assisted laser desorption ionization time-of-flight and reverse-phase high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry revealed the presence of polygalloyl glucoses, catechin, epicatechin, ellagic acid, quercetin-3-o-rhamnoside, and isorhamnetin in eucalyptus bark aqueous extracts.

Antioxidant activity of the phenolic compounds released by hydrothermal treatments of olive tree pruning

The liquors from liquid hot water treatment (LHW) and from steam explosion (SE) of Olea europea pruning were characterised for phenolic content and in vitro antioxidant activity. Rising the temperature treatment enhanced the release of phenolic compounds to the aqueous phase and the fraction of them which are soluble in ethyl acetate was increased. Up to 2.29 and 1.88 g gallic acid equivalents (GAE)/100 g pruning were solubilised in LHW and SE, respectively, 80% of these compounds were recovered in the ethyl acetate extract. Syringol and syringaldehyde were the most abundant lignin derived volatile products identified. Hydroxytyrosol, oleuropein, syringaldehyde and tyrosol were the major phenolic compounds identified by HPLC. The antioxidant activity of the extracts, comparable to that of synthetic antioxidants, depended on the extract concentration but was scarcely affected by treatment temperature.

Encapsulation of Hypericum perforatum (St John's wort) methanolic extract in β-cyclodextrin

Methanolic extracts of Hypericum perforatum (HP) grown in Northern Greece were consistently rich in total polyphenols – reaching 71.9±6.8g gallic acid equivalent (GAE)/100g (N=6) as assayed by Folin Ciocalteu reagent. Among the individual polyphenols identified and quantified by GC/MS in the form of their trimethylsilylethers, epicatechin, catechin and quercetin predominated comprising 94.3±3.2% (N=6) of the determined polyphenols, while their respective concentrations were 118.9±20.6, 8.7±1.4 and 5.8±0.8mg/g extract. Among anthocyanins – determined by HPLC – malvidine was present at 1.96±0.2mg/g.

The influence of flesh colour and growing locality on polyphenolic content and antioxidant activity in potatoes

Compounds contained in potato tubers that may act as antioxidants have been attracting increased attention. The main antioxidants in potatoes are polyphenolic compounds. The total polyphenolic (TP) content and antioxidant activity (AA) in potato tubers of four yellow-fleshed cultivars and two purple-fleshed cultivars from the 2004 harvest were tested. The total polyphenolic content was determined using the Folin-Ciocalteau reagent (FC) and the antioxidant activity, with the DPPH method using stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH·). Significant differences were found in total polyphenolic content between the yellow-fleshed cultivars Karin, Impala, Ditta, and Saturna. Significant differences between yellow and purple-fleshed potatoes were found: the yellow-fleshed cultivars had an average of 2.96 g gallic acid equivalents (GAE) per kg DM, the purple-fleshed cultivars 4.68 g GAE per kg DM. Significant differences in AA between the yellow and purple-fleshed cultivars were determined (yellow-fleshed in an average of 139.3 mg equivalents of ascorbic acid [EAA] per kg DM, purple-fleshed 332.3 mg EAA per kg DM) as well as between the purple-fleshed cultivars Valfi (298 mg EAA per kg DM) and Violette (366 mg EAA per kg DM). The major antioxidants in purple-fleshed cultivars were anthocyanidins petunidin (Valfi 92% rel) and malvidin (Violette 85% rel). Cv. Violette contained three times higher content of anthocyanidins than cv. Valfi. Among four experimental localities, the higher situated potato-growing region of Stachy (locality with the lowest average annual and daily minimum temperatures and the highest sum of precipitation in the vegetative period) differed significantly from other localities by a higher TP content, AA and yield in the analyzed cultivars. A high positive correlation between antioxidant activity and total polyphenolic content with R = 0.8648, R 2 = 0.7478 ( P = 0.0001) was found.