scholarly journals Phenolic and Antioxidant Analysis of Olive Leaves Extracts (Olea europaea L.) Obtained by High Voltage Electrical Discharges (HVED)

Foods ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 248 ◽  
Author(s):  
Irena Žuntar ◽  
Predrag Putnik ◽  
Danijela Bursać Kovačević ◽  
Marinela Nutrizio ◽  
Filip Šupljika ◽  
...  

Background: The aim of this study was to evaluate high voltage electrical discharges (HVED) as a green technology, in order to establish the effectiveness of phenolic extraction from olive leaves against conventional extraction (CE). HVED parameters included different green solvents (water, ethanol), treatment times (3 and 9 min), gases (nitrogen, argon), and voltages (15, 20, 25 kV). Methods: Phenolic compounds were characterized by ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS), while antioxidant potency (total phenolic content and antioxidant capacity) were monitored spectrophotometrically. Data for Near infrared spectroscopy (NIR) spectroscopy, colorimetry, zeta potential, particle size, and conductivity were also reported. Results: The highest yield of phenolic compounds was obtained for the sample treated with argon/9 min/20 kV/50% (3.2 times higher as compared to CE). Obtained results suggested the usage of HVED technology in simultaneous extraction and nanoformulation, and production of stable emulsion systems. Antioxidant capacity (AOC) of obtained extracts showed no significant difference upon the HVED treatment. Conclusions: Ethanol with HVED destroys the linkage between phenolic compounds and components of the plant material to which they are bound. All extracts were compliant with legal requirements regarding content of contaminants, pesticide residues and toxic metals. In conclusion, HVED presents an excellent potential for phenolic compounds extraction for further use in functional food manufacturing.

2018 ◽  
Vol 40 (3) ◽  
Author(s):  
Aline Priscilla Gomes da Silva ◽  
Poliana Cristina Spricigo ◽  
Thais Pádua de Freitas ◽  
Thiago Machado da Silva Acioly ◽  
Severino Matias de Alencar ◽  
...  

Abstract Pereskia aculeata Miller is a native cactaceae found from the Northeast to the South of Brazil. This plant is recognized by the high nutritional value of their leaves, which are the most used in cooking and folk medicine. However, studies on the chemical characteristics and antioxidant capacity of the ora-pro-nobis fruits are scarce. Therefore, the aim of this study was to determine the best harvest point of the ora-pro-nobis fruits to optimize the content of bioactive compounds and their antioxidant capacity. The fruits were manually harvested, defined by their peel colors in three maturity stages: unripe (green), intermediate (yellowish green), and ripe (yellow) stages. The following attributes were evaluated: soluble solids (SS), titratable acidity (TA), SS/TA ratio, pH, and content of bioactive compounds, such as total chlorophylls, carotenoids, yellow flavonoids, total phenolic compounds, and antioxidant capacity. There was a decrease in the content of chlorophyll followed by an increase in the of total carotenoids and yellow flavonoids, due to the maturity stage. For the total phenolic compounds, it was not observed significant difference between the stages. The antioxidant capacity was quantified by the ORAC method in lyophilized pulp in the unripe (1.95 mmol 100 g-1 trolox) and ripe (3.85 mmol 100 g-1 trolox) stages. The lowest contents were observed in the intermediate (0.80 mmol 100 g-1 trolox in lyophilized pulp) stage. The maturity stage significantly influenced the bioactive compounds of ora-pro-nobis, which presented higher values of total carotenoids, yellow flavonoids, and antioxidant capacity in ripe fruits.


2021 ◽  
pp. 109-119
Author(s):  
Darly Rodrigues Pompeu ◽  
Audrey Pissard ◽  
Hervé Rogez ◽  
Pascal Dupont ◽  
Marc Lateur ◽  
...  

Description of the subject. Phenolic compounds are very important to the antioxidant capacity of plant species. Phenolic compounds and hence antioxidant capacity are commonly measured in the laboratory using indirect methods that involve several stages and chemicals. Objectives. This study aims to identify species with high content of phenolic compounds and antioxidant capacity and to measure these parameters in the leaves of fruit species using near-infrared spectroscopy (NIRS). Method. A total of 68 samples of different varieties of Prunus avium, Prunus cerasus, Malus domestica, Prunus domestica, Pyrus communis, Vitis vinifera, Ficus carica and Corylus avellana were investigated. The dried ground leaves were scanned in reflectance mode and the phenolic compound content (total phenolic compounds, total flavanols and total flavonols) and antioxidant capacity (2-2-diphenyl-1-picrylhydazil [DPPH] and oxygen radical absorbance capacity [ORAC]) were determined. Results. Great variability of phenolic compound content and antioxidant capacity was observed between species (inter-species) and between varieties (intra-species). The spectra with and without pre-treatments were tested to correlate with the phenolic compound content and antioxidant capacities. The pre-treatments tested showed a slight improvement in statistical parameters (R²CAL > 0.75; R²CV > 0.21; RPD > 1.1). Conclusions. The results suggest that NIR spectroscopy with chemometric approaches could be used to rapidly estimate the phenolic compound content and antioxidant capacity of the leaves of fruit species. The species evaluated in this study were shown to be a rich source of phenolic compounds and antioxidants.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 234 ◽  
Author(s):  
Yili Hong ◽  
Zening Wang ◽  
Colin J. Barrow ◽  
Frank R. Dunshea ◽  
Hafiz A. R. Suleria

Stone fruits, including peach (Prunus persica L.), nectarine (Prunus nucipersica L.), plum (Prunus domestica L.) and apricot (Prunus armeniaca L.) are common commercial fruits in the market. However, a huge amount of stone fruits waste is produced throughout the food supply chain during picking, handling, processing, packaging, storage, transportation, retailing and final consumption. These stone fruits waste contain high phenolic content which are the main contributors to the antioxidant potential and associated health benefits. The antioxidant results showed that plum waste contained higher concentrations of total phenolic content (TPC) (0.94 ± 0.07 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC) (0.34 ± 0.01 mg quercetin equivalents (QE)/g), while apricot waste contained a higher concentration of total tannin content (TTC) (0.19 ± 0.03 mg catechin equivalents (CE)/g) and DPPH activity (1.47 ± 0.12 mg ascorbic acid equivalents (AAE)/g). However, nectarine waste had higher antioxidant capacity in ferric reducing-antioxidant power (FRAP) (0.98 ± 0.02 mg AAE/g) and total antioxidant capacity (TAC) (0.91 ± 0.09 mg AAE/g) assays, while peach waste showed higher antioxidant capacity in 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay (0.43 ± 0.09 mg AAE/g) as compared to other stone fruits waste. Qualitative and quantitative phenolic analysis of Australian grown stone fruits waste were conducted by liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and HPLC-photodiode array detection (PDA). The LC-ESI-QTOF-MS/MS result indicates that 59 phenolic compounds were tentatively characterized in peach (33 compounds), nectarine (28), plum (38) and apricot (23). The HPLC-PDA indicated that p-hydroxybenzoic acid (18.64 ± 1.30 mg/g) was detected to be the most dominant phenolic acid and quercetin (19.68 ± 1.38 mg/g) was the most significant flavonoid in stone fruits waste. Hence, it could be concluded that stone fruit waste contains various phenolic compounds and have antioxidant potential. The results could support the applications of these stone fruit wastes in other food, feed, nutraceutical and pharmaceutical industries.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 105
Author(s):  
Clarice Silva e Souza ◽  
Pamella Cristine Anunciação ◽  
Ceres Mattos Della Lucia ◽  
Rosana Gonçalves Rodrigues das Dôres ◽  
Regina Célia Rodrigues de Miranda Milagres ◽  
...  

Citrus fruit is preferred in the choice of consumers. Kumquat (F. margarita) is an unconventional citrus of increasing consumer interest because of its exotic flavor, and its functional potential that offers health benefits to consumers. It is a fruit traditionally consumed by whole fruit (peel and pulp), giving this fruit a distinctive flavor. For this reason, this study analyzed the physical, chemical, and nutritional characteristics of kumquat (peel and pulp). The physicochemical analysis was performed according to the Adolfo Lutz Institute. Analysis of moisture, ashes, macronutrients, and total dietary fiber was carried out according to AOAC. Minerals were analyzed by inductively coupled plasma optical emission spectrometry. Vitamins C and E, carotenoids and flavonoids were analyzed by HPLC. Phenolic compounds (Folin-Ciocalteu) and antioxidant capacity (DPPH) were determined by spectrophotometry. The kumquat had low pH, soluble solids content and low caloric value. It was a source of dietary fiber, minerals (K, Ca, P, Mg) and carotenoids; the most expressive was α-carotene (661.81 μg 100 g−1). The ascorbic acid concentration was 2326.24 μg 100 g−1. α-tocopherol (569.00 μg 100 g−1) was the most expressive component of vitamin E. There was a presence of apigenin and eriodictyol. The fruit (peel and pulp) has a high concentration of total phenolic compounds (98.55 ± 1.93 mg GAE 100 g−1) and good antioxidant capacity (62%) was found. Kumquat is a good source of fiber and vitamin A, and due to its antioxidant capacity and the presence of other essential and beneficial nutrients for a diet, consumption of kumquat can be suggested to complement the diet. This fruit is a viable food alternative, and its consumption should be encouraged, contributing a source of income, sovereignty, and food security.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1042
Author(s):  
Silvia Grassi ◽  
Olusola Samuel Jolayemi ◽  
Valentina Giovenzana ◽  
Alessio Tugnolo ◽  
Giacomo Squeo ◽  
...  

Poorly emphasized aspects for a sustainable olive oil system are chemical analysis replacement and quality design of the final product. In this context, near infrared spectroscopy (NIRS) can play a pivotal role. Thus, this study aims at comparing performances of different NIRS systems for the prediction of moisture, oil content, soluble solids, total phenolic content, and antioxidant activity of intact olive drupes. The results obtained by a Fourier transform (FT)-NIR spectrometer, equipped with both an integrating sphere and a fiber optic probe, and a Vis/NIR handheld device are discussed. Almost all the partial least squares regression models were encouraging in predicting the quality parameters (0.64 < R2pred < 0.84), with small and comparable biases (p > 0.05). The pair-wise comparison between the standard deviations demonstrated that the FT-NIR models were always similar except for moisture (p < 0.05), whereas a slightly lower performance of the Vis/NIR models was assessed. Summarizing, while on-line or in-line applications of the FT-NIR optical probe should be promoted in oil mills in order to quickly classify the drupes for a better quality design of the olive oil, the portable and cheaper Vis/NIR device could be useful for preliminary quality evaluation of olive drupes directly in the field.


Author(s):  
Sandoval-Gallegos Eli Mireya ◽  
Arias-Rico José ◽  
Cruz-Cansino Nelly del Socorro ◽  
Ramírez-Ojeda Deyanira ◽  
Zafra-Rojas Quinatzin Yadira ◽  
...  

The aim of the present research was to determine the effect of boiling on nutritional composition, total phenolic compounds, antioxidant capacity, physicochemical and morphological characteristics of two edible plants Malva parviflora (mallow leaf) and Myrtillocactus geometrizans (garambullo flower). The plants had an important nutritional composition as carbohydrates (48-70 %), dietary fiber (36-42 %) and protein (13 %), as well as total phenolic compounds (468-750 mg GAE/100 g db) with a high antioxidant capacity. However, boiling originated the decrease of soluble compounds, carbohydrates, total phenolic compounds, antioxidant capacity and physicochemical properties. Plants changed to dark colors and physicochemical properties were affected, except to water retention capacity, oil retention capacity and viscosity, which had the same values in mallow leaves (raw and boiled), but increased water retention capacity in garambullo flowers, it may be by changes in the morphology observed. Therefore, is to suggest the raw consumption or with minimal cooking of these plants to avoid changes caused by thermal treatment.


2017 ◽  
Vol 30 (1) ◽  
pp. 237-243 ◽  
Author(s):  
MARCOS FILGUEIRAS JORGE ◽  
◽  
KAMILA DE OLIVEIRA DO NASCIMENTO ◽  
JOSÉ LUCENA BARBOSA JUNIOR ◽  
LEONARDO DUARTE BATISTA DA SILVA ◽  
...  

ABSTRACT The objective of this work was to evaluate the physicochemical and microbiological characteristics, antioxidant capacity and phenolic compounds of organic cherry tomatoes grown under fertigation with organic dairy cattle wastewater (DCW) with different nitrogen rates. Tomato plants, grown in an agroecological farm in Seropédica, State of Rio de Janeiro, Brazil, were subjected to four different nitrogen rates (T1=0, T2=50, T3=100 and T4=150% of N). The moisture, lipids, ashes, protein and total fiber contents, soluble solids (ºBrix), reducing and total sugars (%), pH and total titratable acidity (mg NaOH per 100 g) were evaluated. The total phenolic content (TPC) and the antioxidant capacity was determined by the DPPH and FRAP methods. The different nitrogen rates (%N) affected the pH, protein and soluble solids contents. The increase in %N increased the antioxidant capacities, according to the DPPH assay, and TPC. On the other hand, the tomatoes under fertigation with the highest %N presented lower antioxidant capacities according to the FRAP assay. The fertigation did not affect the microbiological characteristics of the tomatoes, which presented fecal coliforms count <3 NMP g-1 and absence of Salmonella in 25 g.


Botanica ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 76-87
Author(s):  
Aziza Lfitat ◽  
Hind Zejli ◽  
Abdelkamel Bousselham ◽  
Yassine El Atki ◽  
Badiaa Lyoussi ◽  
...  

AbstractWe conducted this study to determine and compare the content of phenolic compounds and flavonoids in the argan and olive leaves as well as their antioxidant capacity in aqueous, methanolic, and ethyl acetate extracted fractions. In vitro antioxidant activity was evaluated in comparison with synthetic antioxidants by assessing DPPH• radical scavenging capacity, ferric reducing antioxidant power, scavenging ability by inhibiting the β-carotene/linoleic acid emulsion oxidation, and by the ABTS radical scavenging activity assay. Total phenolic content in argan samples ranged from 221.69 ± 2.07 to 1.32 ± 0.01 mg GAE/g DW and in olive samples from 144.61 ± 0.82 to 1.21 ± 0.02 mg GAE/g DW. Total flavonoids content in argan samples varied from 267.37 ± 1.12 to 25.48 ± 0.02 mg QE/g DW, while in olives from 96.06 ± 0.78 to 10.63 ± 0.05 mg QE/g DW. In vitro antioxidant studies strongly confirmed the antioxidant potency of argan and olive leaves and their richness in secondary metabolites that are effective in free radicals scavenging and metal chelating capacities, indicating their antioxidant power.


2020 ◽  
Vol 6 (2) ◽  
pp. 258-261
Author(s):  
Md. Ariff Farah Fazwa ◽  
Saffie Norhayati ◽  
Samsul Bahari Syafiqah Nabilah ◽  
Sundara Rajoo Keeren

Labisia pumila, locally known in Malaysia as Kacip Fatimah, is highly-prized for its phenols. Phenolic compounds in L. pumila has numerous pharmacological properties such as having anti-oxidant, anti-microbial, anti-inflammatory and anti-cancer potential. The production of phenolic contents in plants is influence by various factor, including abiotic factors such as soil properties. Thus, the objective of this study was to determine the effects of different combinations of growing media on the growth and total phenolic content in L. pumila leaves. Six combinations of growing media were used, each using different types of compost that had differing amounts of L. pumila leaves. The plants were grown in all media for a period of six months at FRIM’s nursery. Besides growth performance, the total phenolic content was also determined, six months after planting. There was no significant difference in growth parameters for all treatments, with the exception of control (significantly lower than all treatments). However, the total phenolic content of Treatment 1 (80.6 mg GAE/g) was significantly higher than all other treatments. This can be attributed to the properties of Compost 1 (which was in the growth media of Treatment 1), as it had the highest pH (5.26), the highest potassium concentration (0.7%) and high nitrogen concentrations (1.32%). The composition of Compost 1 was 5 kg dry leaves + 500 g dry Kacip Fatimah + Slow Release Fertilizer (SRF). Results from this study showed that growing media is a key factor that leads to significant increment in phenolic compounds in L. pumila.


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