Total Phenolic Content

General objective of the present work was to assess the isolation of polyphenols from olive leaves. The effects of extraction conditions on the total phenol content and antioxidant activity of olive leaf extract (OLE) were investigated. An extract with good antioxidant activity (7.52 mmol of Trolox equivalent antioxidant capacity (TEAC)/g olive leaf extract), and a high content of oleuropein (13.4%) and rutin (0.18%) could be obtained using 70% ethanol as extraction solvent. There was a good correlation between the antioxidant activity and the total phenol content. Furthermore, silk fibroin was used as a novel adsorbent to recover the polyphenols from the olive leaf extracts. The adsorbed amounts of rutin and oleuropein were 15 mg rutin/g silk fibroin and 96 mg oleuropein/g silk fibroin. Fraction consisting of mainly oleuropein and fraction rich in rutin, luteolin-7-glucoside, verbascoside, apigenin-7-glucoside were obtained by using silk fibroin filled column. Silk fibroin was found to be a promising adsorbent for the purification of oleuropein and rutin from olive leaf extracts.

seed oil from C. spinosa are available [2–6]. This study was made to analyze the chemical properties of seeds and oil extracted from Capparis spinosa collected from different regions of Dashte-Moghan in order to determine the possibility of commercial utilization and to assess the potential use of the extracted oil in the edible oil industry. Table 1 gives the fatty

Context: There is a wide variety of methods for obtaining of plant extracts that enable a good yield of bioactive metabolites. For several years, extractive techniques have been perfected for obtaining natural extracts with powerful pharmacological properties. Aims: To determine the influence of various extraction methods (infusion, decoction, microwave, maceration with heat and agitation, and constant heat and agitation) on the content of solids, phenolic compounds and antioxidant capacity of marine angiosperms Thalassia testudinum Banks ex König (Hyrocharitacea) and Syringodium filiforme kützing (Cymodoceaceae). Methods: The soluble solids content was determined by the gravimetric method; total phenolic content, using Folin-Ciocalteu method, and the antioxidant capacity by 2,2-diphenyl-1 picrylhydrazyl (DPPH) method. Results: Results showed the effectiveness of extraction by decoction for T. testudinum and by microwave for S. filiforme, among the methods that use water as the extraction solvent. In the case those that use the hydroalcoholic mixture as solvent extraction, maceration with agitation and heat extraction showed the higher yields of soluble solids and total polyphenols, as well as a higher antioxidant activity for both species. Conclusions: Results showed the effectiveness of extraction by decoction for T. testudinum and by microwave for S. filiforme, among the methods that use water as extraction solvent. In the case those that use hydroalcoholic mixture as solvent extraction, maceration with agitation and heat extraction showed the higher yields of soluble solids and total polyphenols, as well as a higher antioxidant activity for both species.

The effects of soaking, boiling and steaming processes on the total phenolic components and antioxidant activity in commonly consumed cool season food legumes (CSFL’s), including green pea, yellow pea, chickpea and lentil were investigated. As compared to original unprocessed legumes, all processing steps caused significant (p < 0.05) decreases in total phenolic content (TPC), DPPH free radical scavenging activity (DPPH) in all tested CSFL’s. All soaking and atmospheric boiling treatments caused significant (p < 0.05) decreases in oxygen radical absorbing capacity (ORAC). However, pressure boiling and pressure steaming caused significant (p < 0.05) increases in ORAC values. Steaming treatments resulted in a greater retention of TPC, DPPH, and ORAC values in all tested CSFL’s as compared to boiling treatments. To obtain cooked legumes with similar palatability and firmness, pressure boiling shortened processing time as compared to atmospheric boiling, resulted in insignificant differences in TPC, DPPH for green and yellow pea. However, TPC and DPPH in cooked lentils differed significantly between atmospheric and pressure boiling. As compared to atmospheric processes, pressure processes significantly increased ORAC values in both boiled and steamed CSFL’s. Greater TPC, DPPH and ORAC values were detected in boiling water than that in soaking and steaming water. Boiling also caused more solid loss than steaming. Steam processing exhibited several advantages in retaining the integrity of the legume appearance and texture of the cooked product, shortening process time, and greater retention of antioxidant components and activities.

Polished rice usually lacks essential elements. Cultivation for increased yield with high nutritional value is thus a challenge. A greenhouse experiment was conducted to determine the effects of nanofertilizer application on the yield, total phenolic content (TPC) and antioxidant activity of rice cv. Ilpum. Results showed that agronomic parameters were significantly enhanced by all combination treatments except for that applied with nanofertilizer only. The full recommended rate of conventional and nanofertilizer (FRR-CF+FRR-NF) enhanced the plant height, chlorophyll content, number of reproductive tillers, panicles, and spikelets. The magnitudes of increase over the FRR-CF were 3.6%, 2.72%, 9.10%, 9.10%, and 15.42%, respectively. Similar results were seen in panicle weight (17.4%), total grain weight (unpolished-17.5%, polished-20.7%), total shoot dry weight (15.3%), and harvest index (2.9%). Half the recommended rate of nanofertilizer enhanced TPC, reducing power and 2, 2’- azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging activity by 51.67%, 36.28%, and 20.93% respectively over the FRR-CF+FRR-NF treatment. TPC (557.55 mg GAE/100g) was higher compared to some pigmented rice cultivars. ABTS assay revealed that the scavenging activity could reach 97.23%. However, the highest hydroxyl scavenging activity registered on the FRR-CF+FRR-NF treatment (55.11%). The chelating capacity and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of the rice extracts did not noticeably differ among treatments. TPC appeared indirectly related to total grain yield and total shoot biomass. Alternatively, a strong positive correlation appeared between TPC and reducing power (94%), as well as ABTS radical scavenging activity (89%). Nanofertilizer application promoted the growth, development, TPC, and antioxidant activity in rice, demonstrating the potential to improve crop production and plant nutrition.

The aim of the present study was to find out the best method for extracting antioxidants from Syzygium cumini L. leaves. The extraction was done by three different methods: sequential cold percolation extraction method, decoction extraction method, and maceration extraction method. Antioxidant activity, total phenol, and flavonoid content were determined in all different extracts of various extraction methods of S. cumini L. leaves. Antioxidant activity was tested by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical, superoxide anion radical and hydroxyl radical scavenging activities, and reducing capacity assessment. Sequential cold percolation extraction method proved to be the best extraction method. The acetone extract had maximum phenol and flavonoid content and showed best DPPH free radical scavenging activity and reducing capacity assessment. Ethyl acetate extract showed best superoxide radical scavenging activity, while aqueous extract showed best hydroxyl radical scavenging activity. It can be concluded that sequential cold percolation extraction method is the best method of extracting leaf antioxidants for this plant at least.