Highest Total Phenolic Values Research Articles

Phytotoxicity and Residual Effect of Some Herbicides on three Egyptian Rice Cultivars (Oryza sativa L.)

The current study was carried out at the experimental farm of Rice Research Department, Sakha Agricultural Research Station and Central Agricultural Pesticide Laboratory, ARC, Egypt during the summer season of 2021 and 2022 to study the sensitivity of three Egyptian rice cultivars against four common herbicides and its effect on physiological and agronomic characteristics of rice as well as herbicide residues in rice seeds. The field study was laid out in split plot design with three replications. Three rice cultivars (Giza 177, Giza 179 and Sakha 108) were randomly distributed in main plots, while weed control treatments included four herbicides at recommended doses (penoxsulam 2.5% OD, bispyribac-sodium 2% SL, cyhalofop-butyl 10% EC and fenoxaprop-p-ethyl 7.5% EW) as compared to hand weeding were devoted in sub plots. The obtained results revealed that Sakha 108 as Japonica rice cultivar was resistant against tested herbicides and recorded the highest values of rice dry weight, chlorophyll content, number of panicles m-2, panicle weight and grain yield, while scored the lowest values of total phenols. On the other hand, Giza 177 as short duration Japonica rice cultivar showed the higher sensitivity against tested herbicides and achieved the lowest values of abovementioned agronomic traits and chlorophyll content. Cyhalofop-butyl as ACCase herbicide was safer on studied rice cultivars and recorded the highest values of studied agronomic characteristics for rice as well as chlorophyll content, while recorded the lowest values of total phenols during the study. On the other hand, bispyribac-sodium 2% SL resulted in more toxic effect for rice cultivars and recorded the lowest values of studied agronomic traits for rice. fenoxaprop-p-ethyl 7.5% EW achieved the lowest chlorophyll content and highest values of total phenols during the study. Giza 179 as Indica-Japonica rice cultivar appeared high sensitivity when sprayed with bispyribac-sodium and fenoxaprop-ethyl but made recovery after 12 days from herbicidal application and recorded the highest chlorophyll content, dry weight, panicles m-2 and grain yield with no significant differences between Sakha 108 rice cultivar during the study. In respect of herbicide residues in rice seeds, all tested herbicides didn’t have residues in rice seeds at 100 days after treatment. It means that tested herbicides didn’t have any residues in rice seeds.

The Natural Alternatives: The Impact of Plant Extracts on Snowbush (Breynia disticha Forst.) Cuttings’ Morpho-Physiological and Biochemical Characteristics

The utilization of cuttings remains a prevalent method for vegetative propagation in various plant species. Synthetic rooting hormones have conventionally been employed to enhance the rooting process; however, their high cost and potential environmental risks have necessitated the exploration of natural alternative compounds. In this study, the efficacy of natural plant extracts (pure honey, aloe extract, willow extract, moringa extract, and cinnamon powder) and synthetic auxin derivatives (indole-3-butyric acid and α-naphthaleneacetic acid) at a concentration of 2000 ppm was compared for their influence on rooting and vegetative growth of snowbush (Breynia disticha) cuttings, a significant ornamental and medicinal shrub. Results demonstrated that while the synthetic hormones produced the highest survival percentages and root number, the roots were consistently short, thick, friable, and largely void of secondary roots. Conversely, the alternative natural plant extracts, particularly aloe extract, exhibited promising outcomes, showcasing good rooting percentage and root number, significantly increased root length, and fresh and dry root weight. Furthermore, aloe extract demonstrated the potential to enhance shoot length and alter the chemical constituents of the cuttings. The highest values of total phenols and nitrogen percentage were recorded with cuttings treated with indole-3-butyric acid, followed by cuttings treated with aloe extract. While using aloe extract, we recorded the highest values of total carbohydrates, phosphorus, and potassium percentages. Notably, the highest endogenous levels of indole acetic acid and gibberellic acid, along with the lowest abscisic acid concentration in cutting tissues, were associated with the highest rooting percentage observed with indole-3-butyric acid, followed by the use of aloe extract. We hypothesized that natural plant extracts, specifically aloe extract, have potential as a viable alternative for synthetic auxins in promoting successful rooting and vegetative growth in snowbush cuttings. Further research is warranted to explore the underlying mechanisms and optimize the application of these natural compounds in vegetative propagation techniques.

Effect of Foliar Fertilization with Humic Acid and Garlic Extract on Growth and Yield of Broccoli and its Content of some Secondary Metabolites

An experiment was conducted in one of the open fields of the Department of Horticulture and Landscape Engineering, College of Agriculture,Al-Qasim Green University for the autumn season 2021-2022. The experiment included a study of three levels of humic acid (0, 2, 4) ml / liter and three levels of garlic extract (0, 10, 20) ml / liter and the interaction between them in the growth and yield of broccoli plant and its content of total phenols and flavonoids. A factorial experiment (3×3) was conducted according to the split plot design and with three replicates, where each replicate contains 9 treatments. Test the least significant difference L.S.D at the level of 5%. The results showed the humic acid at a concentration of 4 ml / liter in excelled and gave the highest plant height of 57.60 cm, the number of leaves 17.46 leaves / plant, the percentage of dry matter 19.06%, the diameter of curd 23.24 cm, the weight of curd 0.736 kg, and the total amount of phenols in the leaves 1.93 mg / kg. Humic treatment at a concentration of 2 ml / L was significantly excelled in the total amount of phenols in the pink disc at a rate of 1.98 mg / kg. The garlic extract at a concentration of 20 ml/L recorded significantly excelled in recording the highest plant height of 58.42 cm, the percentage of dry matter 19.40%, the curd diameter 23.12 cm, and the curd weight 0.766 kg. In the leaves, it reached 38.15 mg / kg,As for the interaction treatments, most of the interaction treatments recorded significantly excelled in most of the studied traits, but the best interaction treatments were H3G3, which recorded the highest number of leaves 13.60 leaves and the percentage of dry matter 19.73% and the diameter of the pink disc 25 cm and the weight of curd 0.870 kg.While treatment H2G2 recorded the highest value of total phenols in leaves 2.07 mg / kg and treatment H3G2 recorded the highest value of flavonoids in leaves 38.37 mg / kg. Treatment H2G1 recorded the highest value of total phenols in curd amounted to 2.10 mg/kg, and treatment H3G1 recorded the highest value of flavonoids in curd amounting to 38.61 mg/kg.

Study of Influence of Extraction Method on the Recovery Bioactive Compounds from Peel Avocado.

The avocado peel is a waste material from consumption avocado (Persea americana Mill.) with big biotechnology potential. The purpose of the present work was to study the influence of six extraction methods, maceration (M), maceration plus β-cyclodextrin (MβC), solid-state fermentation (SSF), sonication with water or ethanol, wet grinding (WG), wet grinding plus maceration (WGM), on the recovery of bioactive compounds from the avocado peel such as total phenols, epicatechin and chlorogenic acid. The results showed that the extraction method has a significant effect on the content of total phenols, the WGM method obtaining the highest value of total phenols (2143.1 mg GAE/100 g dry weight). Moreover, the results indicated that the extraction method had a significant effect on chlorogenic acid and epicatechin recovery, the WGM method obtaining the highest amount of epicatechin and chlorogenic acid, 181.7 and 244.3 mg/100 g dry matter, respectively. Additionally, the characterization of WGM extract was realized by UPLC-ESI-MS/MS and GC-MS. Thus, the WGM method allowed for obtaining good yields of recovery of phenolic compounds using an accessible technology and a more environment-friendly solvent.

A Comparative Study on the Nutritional, Antioxidant, Thermal, Morphological and Diffraction Properties of Selected Cucurbit Seeds

Cucurbit seeds are highly nutritious but generally discarded as a waste by various processing sectors. This study aims to investigate the nutritional profile of seeds of ash gourd, pumpkin, watermelon and musk melon. The techniques, such as mineral, vitamin, amino acid and fatty acid profiling, will provide the nutritional status of the selected seed samples, while the antinutritional accounts will assess the safety of the food application. The thermal behavior of the seeds will guide the decision of the food application of the selected seeds. These seeds were found to be rich in protein and fat, minerals, vitamins and amino acids. The antinutritional compounds in the studied seeds were within the safety limits. Ash gourd seeds had the highest antioxidant activity at 85.11%, with the highest values of total phenols at 176.07 mg GAE/100 g and flavonoids at 159.16 mg QE/100 g. The peaks of the functional group at 3008 cm−1, 1651 cm−1, 1528 cm−1 and 1233 cm−1 denote the presence of polyunsaturated fatty acids, and amide I, II and III, respectively. The thermal analysis of the seeds reviled that the seeds were thermally stable and could be used in product development. The surface morphology was attributed to the interaction of fat, protein and carbohydrates. The semicrystalline or amorphous nature of the seeds resulted in an A-type pattern in the XRD analysis. The results obtained here supports the food application of the selected seeds.

Study the impact of ultra-sonication and pulsed electric field on the quality of wheat plantlet juice through FTIR and SERS

Pulsed electric field (PEF) and Ultrasound (US) are commonly used in food processing. We investigated the combined impact of pulsed electric field (PEF) and ultrasound (US) on the wheat plantlet juice. When compared with the individual treatments, the highest values of total phenolics, total flavonoids, chlorophyll, ORAC assay, and DPPH activities were obtained using the combined (US + PEF) methods. The US + PEF significantly decreased the peroxidase and polyphenol oxidase activities from 0.87 to 0.27 Abs min−1 and 0.031–0.016 Abs min−1. Also, the synergistic application significantly lowered the yeast and mold (3.92 to 2.11 log CFU/mL), E. coli/Coliform (1.95 to 0.96 log CFU/mL), and aerobics (4.41 to 2.01 log CFU/mL). Furthermore, Fourier Transform Infrared (FT-IR) and surface-enhanced Raman spectroscopy (SERS) was used to analyzing juice quality. Gold nanoparticles (AuNPs) were used as the SERS substrates, which provided stronger Raman peaks for the samples treated with US + PEF methods. The FT-IR analysis showed significant enhancement of the nutritional molecules. The enhanced quality of wheat plantlet juice combined with lower yeast and mold suggests the suitability of integrated methods for further research and applications.

Antioxidant, Antibacterial and Antifungal Activities of the Aqueous and Hydroalcoholic Extracts of Western Algerian Urtica urens

Recently, there is a great deal of attention for natural products due to its possible medicinal values. Its effectiveness has been proved through a sever-al studies in defeating some diseases. The present study aimed to investigate the antioxidant, antibacterial and antifungal activities of Urtica urens from Western Algeria. Leaves and roots were extracted with 80 % Ethanol and water. The 2.2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene bleaching tests were used to assess the antioxidant activity in addition to polyphenols analysis, while the agar well diffusion were used to screen the antimicrobial activity against some Gram-positive, Gram-negative bacteria and the fungi. Among the studied extracts, hydroalcoholic extracts of leaves and roots pre-sented the highest total phenolic values (26.2 and 20.9 mg GAE/g), flavo-noids with (15.7 and 12.2 mg quercetin/g) and condensed tannins with (56.4 and 30.1 mg GAE/g), compared to the water extracts. Once again, the 80 % ETOH leaves exhibited the highest antioxidant capacity with an IC50 of 2.59 mg/ml, followed by the water leaves with an IC50 of 6 mg/ml. On the other hand, the hydroalcoholic extracts exhibited the highest inhibition of β-carotene bleaching with 42.6 % to the roots and 37.9 % to the leaves. The ETOH leaves and ETOH roots of U. urens were the most effective extracts being able to repress the growth of the pathological tested strains including fungi. Therefore, it is recommended the use of U. urens that has been poorly recognized for a long time by the population of the selected region.

PHYTOCHEMICAL AND ANTIOXIDANT COMPOSITION IN ACCESSIONS OF THE MANGABA ACTIVE GERMPLASM BANK

ABSTRACT Mangaba (Hancornia speciosa Gomes) is a fruit species native to Brazil, belonging to the Apocynaceae family. Its cultivation is predominantly extractivist and its antioxidant properties have been recently reported. The objective of this study was to evaluate the bioactive compounds and antioxidant activity in fruits of accession from the Active Germplasm Bank of Embrapa Coastal Tablelands (BI, CA, LG, PR, PT and TC). The extracts were analyzed by high-performance liquid chromatography (HPLC), which identified chlorogenic acid (93.71 - 131.66 mg.100g-1), ferulic acid (0.85 - 2.27 mg.100g-1) and rutin (238.59 -442.94 mg.100g-1). The accessions CA and PR showed the highest values of total phenols (1179.39 and 1167.05 mg GAE.100g-1, respectively). The accessions CA and TC had the highest concentration of the major compound rutin (436.78 and 442.94 mg.100g-1, respectively). Antioxidant activity values ranged from 125.95 to 158.67 g.g-1 DPPH. Principal component analysis grouped the accessions into four groups, due to the genetic variability verified in previous studies. The results will be useful to guide actions of selection and future breeding program of the species.

Bioactive activities and chemical profile characterization using paper spray mass spectrometry of extracts of Eriobotrya japonica Lindl. leaves.

The loquat (Eriobotrya japonica Lindl.) is a fruit tree that has been used in Chinese medicine for thousands of years for the treatment of various diseases. The loquat leaf extracts contain several bioactive compounds with antioxidant and antimicrobial properties, and identification of these substances using quick and simple methods has been an analytical trend. The influence of dehydration of loquat leaves (without drying, at 40°C, and at 60°C), the type of solvent (ethanol and methanol), and the method of extraction (shaking and ultrasound) on obtaining extracts containing phenolic compounds and substances with antioxidant and antimicrobial properties was evaluated. The chemical constituents of an extract were identified using paper spray mass spectrometry (PS-MS). The extract obtained from the dehydrated leaves at 40°C presented the best results. The extracts obtained from these leaves and with ethanol had the highest values of total phenolics and antioxidant activities, but the methanolic extract subjected to ultrasound had the highest levels of chlorogenic, caffeic, and ellagic acids. All extracts evaluated inhibited the growth of Staphylococcus aureus. Using the PS-MS technique, it was possible to identify the presence of 49 substances such as organic acids, phenolic acids, flavonoids, sugars, quinones, and terpenes. In general, extracts of dehydrated leaves at 40°C and extracted with ethanol using ultrasound can be considered a good source of bioactive compounds with potential applications as functional ingredients or additives in the food and pharmaceutical industries. PS-MS was demonstrated to be a simple and ultrafast technique to obtain the chemical profile of the loquat leaf extract.

Choline Chloride Based Natural Deep Eutectic Solvents as Extraction Media for Extracting Phenolic Compounds from Chokeberry (Aronia Melanocarpa).

For the isolation of selected phenolic compounds from dried chokeberries, natural deep eutectic solvents (NADESs) were investigated as a green alternative to conventionally used extraction solvents. Four types of NADESs were synthesised, with choline chloride as the hydrogen bond acceptor in combination with different hydrogen bond donors (sugars, organic acid and urea). Ultrasound-assisted extraction was used to improve the extractability of the phenolic compounds and the results were compared to those obtained with 80% methanol as the extraction media. The highest values of total phenols and total flavonoids were found in the extract obtained with choline chloride–fructose NADES (36.15 ± 3.39 mg gallic acid g−1 dry weight (DW) and 4.71 ± 0.33 mg rutin g−1 DW, respectively). The extraction recoveries for the individual phenolic compounds depended strongly on the phenolic compound’s structure, with relative mean values between 70% and 97%.

Bio-chemical properties and susceptibility to fire blight (Erwinia amylovora Burrill) of scab-resistant apple cultivars (Malus domestica Borkh.)

Abstract The focus of our research was to evaluate different apples cultivars in terms of their biological properties and bioactive compounds content, and determine the levels of their resistance (or susceptibility) to fire blight. The properties of 10 scab-resistant apple cultivars were examined on the Žiča monastery estate (West Serbia) during the period from 2011 to 2015. The biological and chemical properties such as firmness, maturity stage, total soluble solids, total acids, total and reducing sugars, ascorbic acid content and surface blush of apple fruits were monitored. Various phenolic compounds in the tested samples were tentatively identified by LC-MS analyses. A study of generative properties included: number of flower buds, fruit mass and width, crop load, yield efficiency and yield. During the period of blooming and intensive shoot growth, artificial inoculations were carried out. For each cultivar, a fire blight score was determined by dividing the average length of necrotic tissue by the average total shoot length. In the study period, the cultivars ‘GoldRush’ (41.1 t ha−1) and ‘Florina’ (35.9 t ha−1) produced the highest yields, and the cultivars ‘Discovery’ (19.0 t ha−1) and Selection 25/63 (15.1 t ha−1) the lowest. The cultivar ‘William’s Pride’ produced the largest fruits, with an average fruit mass of 206.8 g. The earliest harvest period was recorded for the cultivar ‘Discovery’ (end of July), and the latest for the cultivar ‘GoldRush’ (beginning of October). The cultivar ‘Enterprise’ had the highest value of total phenols (432.2 mg 100 g −1 FW), while the cultivar ‘Topaz’ had the highest value of total flavanols (145.2 mg 100 g−1 FW). The highest degree of susceptibility to fire blight was found in Selection 25/63, and the greatest resistance was manifested by the cultivar ‘GoldRush’. In the five-year study period, the cultivars ‘GoldRush’, ‘Rewena’ and ‘Enterprise’ exhibited better bio-chemical properties and higher levels of resistance to fire blight than the remaining cultivars.

Rutin accumulation in gardenia calli cultures as a response to phenyl alanine and salicylic acid

BackgroundRutin is one of the flavonoid compounds found in different plant species. Rutin has powerful antioxidant properties. The main target of this study is to elevate rutin content in gardenia (Gardenia jasmonides Ellis) calli cultures. Different concentrations of phenyl alanine (2, 3, 4, and 5 mg/l) were used as a precursor for enhancement of rutin accumulation. Moreover, and to elevate rutin content, salicylic acid (SA) was used at different concentrations (34.5, 69, 103.5, and 138 mg/l). Various biochemical analyses, i.e., determination of total phenols, total flavonoids, and antioxidant activity during three periods, after 2 weeks (the first harvest), after 4 weeks (the second harvest), and after 5 weeks (the third harvest) of culture, were performed. In addition, determination of phenols and flavonoids content by high-performance liquid chromatography (HPLC) were estimated of the three periods.ResultsThe results showed that the highest value of total phenols (9.53 ± 0.55 mg GAE/g DW of callus) was recorded with 5 mg/l phenylalanine (PA) at the third harvest. While the highest value of total flavonoids (0.358 ± 0.002 mg QE/g DW of callus) was achieved using 2 mg/l P.A. at the third harvest. By using HPLC, it was found that the maximum rutin content was recorded with 3 mg/l PA at the third harvest (429 μg/g DW).ConclusionThis study showed that rutin and cinnamic acids were the major compounds detected with all treatments and during the three harvest phases of gardenia calli cultures. As well as results declared that the decreasing of cinnamic acid was correlated with the increasing of rutin content, and the maximum rutin content was recorded with applying of 3 mg/l PA at the third harvest (429 μg/g DW).

Physicochemical and microbiological characterization of olive mill wastewater (OMW) from different regions of northern Morocco

ABSTRACT This work examined the influence of crop season, extraction system and production site on the composition of fresh olive mill wastewater collected from northern Morocco. ANOVA analysis showed that most of the traits were largely affected by the extraction system (≥60% of total variance). Comparison among extraction systems showed significant differences for all traits, except for chlorides. Three phase centrifugation system (C3) displayed the highest value of total phenols, while all the remaining traits were higher in two phase centrifugation system (C2). Concerning crop seasons, we noticed a general decrease in values of total solids, chemical oxygen demand, chlorides, C/N ratio and total aerobic mesophilic flora, from 2014 to 2016 season; in contrast, an increase in suspended solids, total kjeldahl nitrogen and proteins was detected. OMW with highest total phenols content and then more acidic were collected during 2015 season. Between production sites, Bni Frassen produced OMW with the highest values for salt and total phenols, but the lowest ones were obtained for microbiological traits. OMW from Taza were rich in total kjeldahl nitrogen and proteins. An increase in organic load indicators was observed in Bouchfaa. Principal component analysis (PCA) explained about 82% of total variability: 58%, 16% and 8% for principal component 1 (PC1), PC2 and PC3, respectively. Extraction system fitted the variability of PC1. PC2 was mainly explained by production sites, while PC3 separated crop seasons. Correlation studies showed significant relationships especially among the traits expressing organic load, while microbiological counts were largely associated to total phenols and pH.

Phenolic compounds and phytochemicals in fruits of black mulberry (Morus nigra L.) genotypes from the Aegean region in Turkey

Abstract Turkey is one of the most important centres of mulberry genetic resources and mulberries grow naturally almost everywhere in Turkey. This study was carried out to determine the most important phenolic compounds and phytochemical properties of mulberry (Morus nigra L.) genotypes collected from natural resources in 2016-2017 in the province of Uşak (Turkey). The investigated biochemical characteristics included: total soluble solids content (TSS), pH, titratable acidity, total phenolic content, vitamin C and antioxidant capacity (DPPH). The highest values of phenolic compounds, i.e. ellagic acid, rutin, quercetin, gallic acid, catechin, chlorogenic acid and caffeic acid, were as follows: 5.89, 133.60, 11.25, 40.90, 10.54, 97.59 and 21.93 g 100 g−1, respectively. The highest values of total phenolics, vitamin C content and antioxidant capacity determined in the investigated mulberry genotypes were 2977.30 mg GAE g−1, 31.34 mg 100 g−1 and 26.80%, respectively. The genotypes 64USA08, 64USA06 and 64USA10 can be recommended in terms of the most valuable chemical composition and used for future breeding purposes. It is desirable to take steps to implement an intensive programme for the preservation of Morus nigra L. biodiversity in Turkey.

Utilization of Orange, Banana and Potato Peels Versus their Ethanolic Extracts as Antioxidants in Corn Oil

The present study was conducted on three different peels namely, orange, banana and potato along with their ethanolicextracts to reveal their antioxidant potency. Orange peels (OP), banana peels (BP) and potato peels (PP) had the following gross chemical composition: The range of moisture (71.98 – 87.16 %), crude protein (4.99 – 7.89%), total lipids (1.48 – 10.17%), ash (5.64 – 9.41%) and carbohydrates (77.72 – 82.38%). The OP exhibited the highest values of total phenolics (1715.91 mg gallic acid (GA) equivalent / 100g), ascorbic acid (130.82 mg / 100 g) and β- carotene (6.15 mg /100 g) on dry weight basis. Furthermore, the OP ethanolic extract had the highest DPPH• % scavenging (55.00%), the highest H2O2 % scavenging (42.40%) and the lowest IC50 (6.13 mg / mg DPPH•) as compared to BP and PP extracts. It was obvious that the peels under study along with their ethanolic extracts exhibited potent antioxidant activity for corn oil. However, OP and its extract were superior in terms of lowering peroxide value, ρ- anisidine value and totox value along with treatment with BHT for oils stored at 60°C for 25 days, as compared to the control oil. No significant differences could be traced in this respect between OP and its ethanolic extract.

Commercial enological tannins: Characterization and their relative impact on the phenolic and sensory composition of Carménère wine during bottle aging

The effect of the addition of different commercial enological tannins (CETs) on the characteristics of Carménère red wine was evaluated. Initially, chemical characterization of eleven CETs was performed using spectrophotometric and HPLC-DAD techniques. Then, the effects of six CETs on the properties of a Carménère wine during bottle storage (90 days) were evaluated for up to 90 days. Four CETs from wood exhibited highly variable phenolic compositions and the highest values of hydrolyzable tannins and phenolic acids, whereas the CETs from grapes exhibited the highest values of the mono-, oligo- and polymer fractions of flavan-3-ol. The wines enriched with grape CETs presented the highest values of (+)-catechin, (−)-epicatechin, and monomers and polymers of flavan-3-ols, whereas some wines enriched with wood CETs exhibited the highest values of total phenols, total tannins, dihydroflavonols, proanthocyanidin gallates, syringic acid and flavan-3-ol oligomers. Analysis of temporal dominance of sensations revealed no significant differences in the astringency or bitterness perceptions by a trained panel. Altogether, CETs are highly diverse products that can differentially impact the physicochemical and sensorial characteristics of wines to which they are added. Characterization of CETs before their application in winemaking is highly recommended.

Bioactive Compounds and Antioxidant Potential of Food Industry By-products in Egypt

The present study was carried out to examine the bioactive compounds and antioxidant potential of four food industry by-products (potato peel, cauliflower leaves, onion skin and mango peel) in Egypt. The total dietary fiber content for all tested by-products was ranged 27.15-42.71 g.100g-1, total carotenoids was 92.43- 412.14 mg.100g-1 and total phenolics was 1104-7129 mg GAE.100 g-1. The mango peel powder (MPP) was recorded the highest content of total dietary fiber and total carotenoids while red onion skin powder (ROSP) recorded the highest values of total phenolics. The food by-product extracts showed considerable differences in antioxidant activity when it was calculated by the four different methods used in this study. The antioxidant value (AOX, A/h), antioxidant activity (AA,%), oxidation rate ratio (ORR) and Antioxidant activity coefficient (AAC) were ranged 0.017-0.106, 81.23-96.98, 0.030-0.187 and 584.46-858.27, respectively. ROSP showed strong antioxidant activity followed by MPP, PPP and CLP, respectively. Correlation analysis indicated that there were a strong positive significant relationship (r2 = 0.741-0.962, p≤ 0.01) between total phenolics content and antioxidant activity and a positive significant relationship (r2 = 0. 604-0.718, p≤ 0.05) between total carotenoids content and antioxidant activity in all tested by-products. These correlations confirm that phenolic compounds mainly with carotenoids partially are responsible for the antioxidant activity of the tested by-products. In conclusion, data of the present study revealed that food industry by-products can be good sources of valuable bioactive compounds and antioxidants subsequently extend their potential uses in nutritional and therapeutic applications.

Phytotoxicity of three Plantago species on germination and seedling growth of hairy beggarticks (Bidens pilosa L.)

Plantago genus has a wide geographical distribution all over the world. It has been widely used in folk medicine for various purposes, where it is used as anti-inflammatory, antimicrobial and antitumor agent. In this research, total phenols, tannins, saponins, flavonoids and alkaloids were determined in Plantago lagopus, Plantago major and Plantago squarrosa. Furthermore, concentrations of 2.5, 5, 7.5 and 10 mg ml−1 of both alcoholic and aqueous extracts were prepared to study their phytotoxic effect on the germination and seedling growth of the noxious weed Bidens pilosa. P. major expressed the highest values of total phenolics, tannins and flavonoids. However, P. lagopus has the highest content of alkaloids. The germination of B. pilosa was completely inhibited under treatment of P. lagopus and P. major methanolic extracts at 7.5 mg ml−1 and 10 mg ml−1, respectively. However, the allelopathic effect of P. lagopus aqueous extract showed a complete inhibition of B. pilosa germination followed by P. major. The germination inhibition of B. pilosa increased with the increase in the extracts concentration. In addition, both radicle and plumule were strongly inhibited under the same treatment. Our results showed a potent allelopathic effect on B. pilosa that could be valorized in managing this noxious weed as an ecofriendly bio-control method. However, other studies are needed for the identification, characterization of the responsible allelochemicals and for the demonstration of their modes of action.

English

Antioxidants are beneficial compounds found in a lot of foods. Cordia africana (Lam.) is a small fruit eaten all over Tigray and other parts of Ethiopia. The fruit was tested for its antioxidant content using the ferric reducing antioxidant power (FRAP) assay and total phenols (TP) measured with Folin Ciocalteu`s reagent, across four different agroecological zones and three land use classes in Tigray. The average FRAP value on dry weight basis was 30.8 ± 1.45 mg Trolox equivalent 100 g-1 fruit, and the average TP value on dry weight basis 2317.0 ± 104.0 mg gallic acid equivalent 100 g-1 fruit. Both FRAP and TP values were found to be significantly (p < 0.05) different across the agroecology with the lower altitude agroecology giving the highest value and the dry mid altitude agroecology giving the least value. The difference in land use showed no effect on the FRAP value; however the TP values were significantly (p < 0.01) different across the different land use. The highest value of TP was found in the wild and the lowest was found in the backyard land uses. C. africana is a fruit with good quantities of TP, and small amounts of antioxidants measured with FRAP. Both FRAP and TP values showed variation across agroecology, while only the TP content vary across land use. The fruit was also found to have 9.07 mg 100 g -1 fruit, which makes it a good source of the vitamin to meet part of the daily requirement. As antioxidants and vitamin C are highly beneficial to general health, the consumption of this fruit should thus be recommended and promoted.   Key words: Cordia africana fruit, ferric reducing antioxidant power, total phenol, agroecology, land use.

Antioxidant activities of phenolics, flavonoids and vitamin C in two cultivars of fennel (Foeniculum vulgare Mill.) in responses to organic and bio-organic fertilizers

Field experiment was conducted to study the effect of organic and bio-organic fertilizers on dry weight; yield, total phenolics (TPC), total flavonoids (TFC), vitamin C and on their antioxidant activities of two sweet fennel cultivars Dolce and Zefa fino. Results strongly showed that there were significant differences between sweet fennel cultivars. Generally the highest values of all parameters were obtained when fennel plants were supplemented with 50% NPK+50% organic fertilizer and bio fertilizer when compared with control treatment. The highest values of TPC, TFC and Vit. C were recorded by Zefa fino cultivar when received 50% NPK+50% organic treatment. The antioxidant activities of both cultivars were evaluated and Dolce cultivar showed the highest DPPH scavenging activity expressed as IC50 compared with Zefa fino cultivar. In addition, Dolce cultivars exhibited the highest value for Fe2+-chelating activities for organic and bio-organic fertilizers followed by Zefa fino when compared to control treatment. Dolce cultivar generally showed superiority than Zefa fino in all measured parameters.