Phenolic compounds from Citrus leaves: antioxidant activity and enzymatic browning inhibition

Author(s):  
Bachra Khettal ◽  
Nabil Kadri ◽  
Karim Tighilet ◽  
Ahmed Adjebli ◽  
Farid Dahmoune ◽  
...  

AbstractBackgroundPhenolic compounds fromMethodsMethanolic and aqueous extracts were isolated fromResultsThe results showed that aqueous extracts of all species are rich in total phenolic compounds and flavonoids (from 68.23 to 125.28 mg GAE/g DM) and (from 11.99 to 46.25 mg QE/g DM) respectively. The methanolic and aqueous extracts were examined forConclusionsIn this investigation, the assessment of antiperoxidase activity proved that the leaves extracts of different species were able to inhibit peroxidase activity. However, this inhibition varied with the species and the source of these enzymes. On the other hand, the aqueous extracts of different species showed moderate inhibition of polyphenol oxidase, while no effect on these enzymes was obtained with methanolic extracts.

2015 ◽  
Vol 10 (7) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Jaime Usano-Alemany ◽  
Lachinee Panjai

Lavandin is a well-known aromatic plant cultivated mainly for its valuable essential oil. Nonetheless, little attention has been paid so far to the quantification of other natural products such as polyphenols. Accordingly, we examined the effect of increasing doses of UV-B radiation on the main phenolic content, antioxidant activity and estimated biomass of one year old lavandin pots compared with pots grown outdoors. Significantly higher total phenolic content and concentration of main polyphenols have been found in outdoor plants. Rosmarinic acid has been described as the major phenolic compound in methanolic extracts (max. 25.9±9.7 mg/g−1 DW). Furthermore, we found that increasing doses of UV-B promote the plant growth of this species as well as the accumulation of phenolic compounds although with less antioxidant capacity in scavenging DPPH radicals. On the other hand, our results showed a remarkable variability among individual plants regarding the content of major phenolic acids. The application of UV-B doses during plant growth could be a method to promote biomass in this species along with the promotion of higher content of valuable secondary metabolites.


2021 ◽  
pp. 1-10
Author(s):  
Leandro Marcolino Vieira ◽  
Renata de Almeida Maggioni ◽  
Jéssica de Cássia Tomasi ◽  
Erik Nunes Gomes ◽  
Ivar Wendling ◽  
...  

Abstract Ilex paraguariensis, commonly known as yerba mate, is a tree species native to South America. Its commercial value is due to the manufacturing of teas, with potential also in the pharmacological and cosmetic industries. Vegetative propagation of yerba mate is considered an innovation to the traditional production systems based on sexual propagation. The present study aimed to evaluate the rhizogenic potential and chemical attributes of mini-cuttings from 15 yerba mate genotypes, as well as to verify the correlation between phytochemical and rooting-related variables. Mini-cuttings were collected from a pre-existing mini-clonal hedge and the experimental design was completely randomized, with 15 treatments (genotypes), four replications and 10 mini-cuttings per plot. After 120 days, mini-cuttings were assessed regarding rooting, mortality, callogenesis and leaf retention percentages, percentage of mini-cuttings with both calluses and roots, number of roots and average root length. At the time of collection, subsamples from each plot were used for phytochemical analyses including total phenolic compounds, protein, caffeine and theobromine contents and antioxidant activity. Rooting percentages ranged from 5 to 72.5%, with significant variation among genotypes. Adventitious rooting and phytochemical profile of yerba mate mini-cuttings are genotype-dependent. Leaf retention is a relevant factor in the rooting of yerba mate mini-cuttings and the levels of total phenolic compounds, antioxidants and theobromine present in mini-cuttings are negatively correlated components to Ilex paraguariensis adventitious rooting.


Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 137
Author(s):  
Luis F. Castro ◽  
Abigail D. Affonso ◽  
Renata M. Lehman

Specialty malts are commonly used in brewing to provide flavor, aroma, and color to wort and beer. The use of specialty malts contributes to the variety of beer products; therefore, it is important to understand their effect on the characteristics of wort and beer. This study investigates the impact of various specialty malts on wort and beer properties. A control beer was prepared with 100% base malt, and four beer treatments were prepared with the addition of kilned, roasted, and caramel specialty malts. For each treatment, 20% of the base malt was substituted with the various specialty malts when preparing the wort. The fermentable sugars and free amino nitrogen (FAN) content for each wort were analyzed. Alcohol by volume (ABV), international bitterness units (IBU), diacetyl, and polyphenol content of each prepared beers were subsequently analyzed. Results showed that wort prepared with the addition of roasted and caramel malts contained a lower concentration of fermentable sugars and FAN than wort prepared with the base and kilned malts. Beers prepared with the addition of roasted and caramel malts exhibited the lowest levels of ABV, as well as the lowest levels of diacetyl. These beers also exhibited higher levels of total phenolic compounds compared to the other beer samples. No change was observed in IBU levels as a result of brewing with the different specialty malts. This study illustrates how the use of specialty malts impacts wort and beer properties, providing useful information to aid in the production of quality beer products.


2015 ◽  
Vol 15 (2) ◽  
pp. 173-186 ◽  
Author(s):  
Raquel P. F. Guiné ◽  
Maria João Barroca ◽  
Fernando J. Gonçalves ◽  
Mariana Alves ◽  
Solange Oliveira ◽  
...  

2013 ◽  
Vol 19 (No. 4) ◽  
pp. 139-142 ◽  
Author(s):  
R. Amarowicz ◽  
M. Karamać ◽  
S. Weidner

An extract of seeds of pea was prepared using 80% (v/v) acetone. Six fractions (I–VI) were separated from the crude extract on a Sephadex LH-20 column using methanol as the mobile phase. The antioxidant activity of fractions was investigated in a β-carotene-linoleate model system. For individual fractions, UV spectra were recorded and the content of total phenolics was determined. Results of the β-carotene-linoleate model system indicated that antioxidant activities of separated fractions correlated with their content of total phenolic compounds and they decreased in the order of IV = VI > V > III > I > II. The antioxidant activity of fractions IV and VI was very strong as compared with that of butylated hydroxyanisole (BHA). Absorption maxima from UV spectra showed that flavonoids, and not phenolic acids, were the main phenolic compounds in separated fractions.


2015 ◽  
Vol 29 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Jana Šic Žlabur ◽  
Sandra Voća ◽  
Nadica Dobričević ◽  
Mladen Brnčić ◽  
Filip Dujmić ◽  
...  

Abstract The aim of the present study was to reveal an effective extraction procedure for maximization of the yield of steviol glycosides and total phenolic compounds as well as antioxidant activity in stevia extracts. Ultrasound assisted extraction was compared with conventional solvent extraction. The examined solvents were water (100°C/24 h) and 70% ethanol (at 70°C for 30 min). Qualitative and quantitative analyses of steviol glycosides in the extracts obtained were performed using high performance liquid chromatography. Total phenolic compounds, flavonoids, and radical scavenging capacity by 2, 2-azino-di-3-ethylbenzothialozine- sulphonic acid) assay were also determined. The highest content of steviol glycosides, total phenolic compounds, and flavonoids in stevia extracts were obtained when ultrasound assisted extraction was used. The antioxidant activity of the extracts was correlated with the total amount of phenolic compounds. The results indicated that the examined sonication parameters represented as the probe diameter (7 and 22 mm) and treatment time (2, 4, 6, 8, and 10 min) significantly contributed to the yield of steviol glycosides, total phenolic compounds, and flavonoids. The optimum conditions for the maximum yield of steviol glycosides, total phenolic compounds, and flavonoids were as follows: extraction time 10 min, probe diameter 22 mm, and temperature 81.2°C.


2018 ◽  
Vol 48 (3) ◽  
pp. 386-396 ◽  
Author(s):  
Vania Silva Carvalho ◽  
Ana Carolina Conti-Silva

Purpose This paper aims to examine the bioactive compounds and texture properties of cereal bars formulated with banana peel flour during storage. Design/methodology/approach Seven cereal bars were produced and stored during 11 months, under vacuum and protected from the light. The total phenolic compounds, the activity antioxidant by ABTS [2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] method, the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) method expressed as EC50 (concentration required to reduce the original amount of free radicals by 50 per cent) and texture properties were evaluated over the storage period. Findings In general, total phenolic compounds decreased during storage (from 4.19 to 1.11 mg GAE. g-1f.w.). Although the total antioxidant activity (ABTS method) increased during the fifth month, it reduced during storage (from 3.41 to 0.30 µmol TE.g-1f.w.); and the EC50 was not modified in many formulations, though it decreased in other formulations during storage period (from 3913 to 19221 g fruit.g-1 DPPH). The force of rupture began to increase in the fourth month (reaching 62.4 N), and hardness began to increase in the ninth month (reaching 444 N). The formulation and time factors influenced the total phenolic compounds, total antioxidant activity (ABTS method), force of rupture and hardness, while EC50 was only influenced by the formulation (p-value = 0.001). A principal component analysis showed that time had little effect on the most important characteristics considered in description of the cereal bars. Originality/value Cereal bars can be consumed up to the third month of storage, considering the texture of the products. Moreover, the presence of bioactive compounds in cereal bars depends on the addition of banana peel flour, which it contributes to the insertion of total phenolic compounds and total antioxidant activity in cereal bars, aggregating functional properties in these products.


2013 ◽  
pp. 421-425 ◽  
Author(s):  
A. Graifenberg ◽  
L. Marchetti ◽  
M. Curadi ◽  
N. Ceccarelli ◽  
P. Picciarelli

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