Microwave Pretreatment of Vegetable Materials to Increase the Extraction Yield of Natural Products

2018 ◽  
Vol 69 (8) ◽  
pp. 1976-1979
Author(s):  
Ioana Asofiei ◽  
Ioan Calinescu ◽  
Adina Ionuta Gavrila ◽  
Daniel Ighigeanu ◽  
Diana Martin

It was designed and built a laboratory experimental installation (LEI) for the microwave pretreatment of vegetable materials. To study the influence of microwave pretreatment on the total phenolic content (TPC), a conventional extraction of polyphenols from treated and untreated fresh sea buckthorn leaves was performed. For short extraction times, the amount of phenolic compounds was higher for the extracts obtained from treated leaves, but a long pretreatment time (28 s) led to a decrease in TPC. The qualitative analysis showed that the chemical composition is not affected by the microwave pretreatment.

2018 ◽  
Vol 46 (2) ◽  
pp. 449-456 ◽  
Author(s):  
Hacer COKLAR ◽  
Mehmet AKBULUT ◽  
Semih KILINC ◽  
Ali YILDIRIM ◽  
Iliasu ALHASSAN

Flowers, leaves and fruits of hawthorn plant are traditionally used for treating diseases like hypertension and atherosclerosis. The medicinal effects of the plant are generally attributed to its phenolic compounds. However, the fruits are perishable materials because of their high content of water, and generally dried and stored to be used outside its season. The main aim of this research was to investigate the effect of different drying methods on phenolic compounds of the hawthorn fruit. Fruits were collected from the wild growing trees in Turkey. De-seeded fruits were dried in freeze-, oven- (60 oC) and microwave pretreated oven drying (microwave application for 5 min at 360 W before drying at 60 oC) methods and analyzed for antioxidant activity, phenolic compounds, total phenolic content and color parameters. Total phenolic content of fresh hawthorn fruits was found as 13.36 mg g-1 DW. Oven- and microwave pretreated oven drying methods had a reductive effect on total phenolic content and antioxidant activity of fruits when compared to freeze drying method. (-)-Epicatechin (994.10 mg kg-1 DW), rutin (765.30 mg kg-1 DW), and procyanidin B2 (553.80 mg kg-1 DW) were the main phenolics of the fruit. Lowest values of these three compounds were observed in oven-dried fruits. Microwave pretreatment oven drying method resulted in browner product. Although the highest phenolic concentration and antioxidant activity were occurred in freeze-dried sample, microwave pretreatment before oven drying could be applied to reduce the time and cost of drying in terms of phenolic compounds and antioxidant activity.


2018 ◽  
Vol 25 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Izabela Jasicka-Misiak ◽  
Anna Poliwoda ◽  
Magdalena Petecka ◽  
Olena Buslovych ◽  
Vladimir A. Shlyapnikov ◽  
...  

Abstract The differences in the chemical composition of the phenolic compounds of Salvia officinalis versus Salvia sclarea growing in different habitats, were studied. First, the optimal solvent - methanol - for ultrasonic extraction of phenolic compounds from these plants was chosen experimentally. Total phenolic content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were determined spectrophotometrically. Total phenolic content was in the range of 63.9 to 134.4 mg GAE/g of plant depending on the studied species. The highest antiradical activity was displayed by the methanol fractions of S. sclarea varieties (83 and 67%). HPLC-DAD analysis of extracts was done in order to identify the presence of individual phenolic compounds. This was done by comparison of their retention times with those observed for 17 commercially available standard compounds. The results showed differences in the phenolics composition, with plants collected on Crimean peninsula accumulating more phenolic acids than Polish varieties. In turn, the Polish varieties of sage contain bigger amount of flavonoids in their tissues.


2020 ◽  
Vol 23 (9) ◽  
pp. 939-944
Author(s):  
Merve Keskin

Background: Propolis is a resinous mixture collected by honeybees from tree buds and exudates of the plants. Propolis contains aromatic acids, diterpenic acids and phenolic compounds and these components are responsible for its antitumor, anticancer, antiviral and antifungal effects. Propolis can be extracted and the solubility of propolis differs depending on the solvent used in the process of extraction. Solvents used for propolis extraction have a great impact on the propolis extract and should be nontoxic. Objective: In this study, raw propolis was extracted by peppermint and clove volatile oils. Methods: Chemical composition of extracts was determined by using GC-MS equipment. Total phenolic content and antioxidant activity of the extracts were measured. α-amylase inhibitory activity of the extracts was carried out as well. Results: The findings of the present study showed that clove volatile oil is more effective in the extraction of propolis than peppermint volatile oil. The total phenolic content of these extracts was determined as 175.12 and 40.80 mg GAE/mL for clove and peppermint oil propolis extracts, respectively. All extracts contained the same phenolic compounds but the quantity was less in volatile oil extract than in ethanol extract. Both of these extracts showed better α-amylase ınhibitory activity than a reference inhibitor, acarbose. Conclusion: It could be concluded that propolis extract obtained by using volatile oils could be used as a complementary agent in the treatment of type 2 diabetes mellitus.


2021 ◽  
Vol 11 (15) ◽  
pp. 6941
Author(s):  
Cláudia M. B. Neves ◽  
António Pinto ◽  
Fernando Gonçalves ◽  
Dulcineia F. Wessel

Elderberry (Sambucus nigra L.) juice concentrate is highly rich in polyphenols, particularly anthocyanins and flavonols, which have been associated with a wide range of health-promoting properties. Phenolic compounds, in particular anthocyanins, are unstable and may change during storage, which might influence the product color quality and its potential health effects. The aim of this study was to evaluate the changes in the polyphenols profile of elderberry juice concentrate produced at an industrial scale during seven months of storage at 5 °C and at room temperature. The total phenolic content, the total monomeric anthocyanins, the percent polymeric color, and the ABTS•+ scavenging activity were monitored over time. In addition, the profile and content of the main individual phenolic compounds were also assessed by HPLC-DAD. The results show that cyanidin-3-O-sambubioside, cyanidin-3-O-glucoside, cyanidin-3-O-sambubioside-5-O-glucoside, cyanidin-3,5-O-diglucoside, chlorogenic acid, rutin, and quercetin-3-O-glucoside were the main phenolic compounds identified. Storage at room temperature resulted in a strong reduction in total monomeric anthocyanin content accompanied by an increase in percent polymeric color values. Cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside degraded faster than cyanidin-3,5-O-diglucoside and cyanidin-3-O-sambubioside-5-O-glucoside. Concentration of chlorogenic acid also decreased over storage, whereas rutin and quercetin-3-O-glucoside were quite stable. Storage at 5 °C caused a lower impact on the contents of anthocyanins and chlorogenic acid and the percent polymeric color was not affected. The total phenolic content and the in vitro antioxidant activity remained quite similar over the time, for both temperatures, suggesting that elderberry concentrates still preserve their health benefits of antioxidant capacity after seven months of storage.


Author(s):  
Anna Maria Mannino ◽  
Valentina Vaglica ◽  
Elisabetta Oddo

Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae) contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica) were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.


2015 ◽  
Vol 0 (0) ◽  
Author(s):  
Deep Jyoti Bhuyan ◽  
Quan V. Vuong ◽  
Anita C. Chalmers ◽  
Ian A. van Altena ◽  
Michael C. Bowyer ◽  
...  

AbstractEucalyptus species have found their place in traditional medicine and pharmacological research and they have also been shown to possess a large number of phenolic compounds and antioxidants. The present study sought to implement conventional extraction to yield maximal total phenolic content (TPC), total flavonoid content (TFC), proanthocyanidins, antioxidants, and saponins from E. robusta using different solvents. The most suitable extraction solvent was further employed for extracting phytochemicals from E. saligna, E. microcorys, and E. globulus to select the Eucalyptus species with the greatest bioactive compound content. The results emphasised the efficiency of water in extracting TPC ((150.60 ± 2.47) mg of gallic acid equivalents per g), TFC ((38.83 ± 0.23) mg of rutin equivalents per g), proanthocyanidins ((5.14 ± 0.77) mg of catechin equivalents per g), and antioxidants ABTS ((525.67 ± 1.99) mg of trolox equivalents (TE) per g), DPPH ((378.61 ± 4.72) mg of TE per g); CUPRAC ((607.43 ± 6.69) mg of TE per g) from E. robusta. Moreover, the aqueous extract of E. robusta had the highest TPC, TFC and antioxidant values among the other Eucalyptus species tested. These findings highlighted the efficiency of conventional extraction in extracting natural bioactive compounds from Eucalyptus species for pharmaceutical and nutraceutical applications.


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.


Food Research ◽  
2021 ◽  
Vol 5 (6) ◽  
pp. 172-177
Author(s):  
B. Yudhistira ◽  
N.A. Choiriyah

Roselle contains high phenolic compounds, mainly anthocyanins that are not stable with pH, metal ions, light exposure, temperature, oxygen, and enzymatic activity. The stability of phenolic compounds can be improved by nanoencapsulation. This research was aimed to evaluate the effect of inulin, inulin-chitosan and inulin-chitosan-maltodextrin with varying concentrations as encapsulants towards the physicochemical properties and encapsulation efficiency of nanocapsules product by spray drying. Roselle extract nanocapsules were prepared using various types and concentrations of encapsulants (inulin, inulin-chitosan and inulin-chitosan-maltodextrin). The solubility of nanocapsules ranged from 69.31 - 83.2%, while the hygroscopicity of nanocapsules was varied, approximately 17.89 - 23.79%. Nanocapsules moisture content was approximately 2.83 - 4.27%, while the total phenolic content of nanocapsules ranged from 6.74 - 13.41 mg GAE/g DW. The total anthocyanin of roselle extract nanocapsules was approximately 2.25 - 4.82 mg/g DW. The encapsulation efficiency of phenolic compounds in this study were approximately 60.31 - 77.13%. Nanocapsules with inulin-chitosan-maltodextrin (2.4%-2.4%-0.2%) had good properties of nanocapsules such as good solubility, high total phenolic content and total anthocyanin content. Nanocapsules with 5% inulin and inulinchitosan-maltodextrin (2.4%-2.4%-0.2%) had particle size of 641.4 and 411.1 nm respectively. The nanocapsules had a spherical shape, smooth surfaces but also a few had indentations.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1287
Author(s):  
Tafadzwa Kaseke ◽  
Umezuruike Linus Opara ◽  
Olaniyi Amos Fawole

Microwave pretreatment of oilseeds is a novel technique used to enhance oil nutraceutical properties. In this study, the effect of microwave pretreatment of seeds was investigated on pomegranate seed oil quality attributes including oil yield, yellowness index, refractive index, peroxide value, ρ-anisidine value, total oxidation value, conjugated dienes, total phenolic content, total carotenoids content, phytosterol composition, fatty acid composition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, and ferric reducing antioxidant power (FRAP). The seeds of three different pomegranate cultivars (‘Acco’, ‘Herskawitz’, and ‘Wonderful’) were microwave heated at 261 W for 102 s. Pomegranate seeds microwave pretreatment enhanced oil yield, yellowness index, total carotenoids content, total phenolic content, FRAP and DPPH radical scavenging capacity, despite an increase in conjugated dienes, and peroxide value. Palmitic acid, oleic acid, linoleic acid, saturated, and monosaturated fatty acids were increased after pomegranate seeds microwave pretreatment, whilst the levels of punicic acid and β-sitosterol were reduced. Nevertheless, the refractive index, the ratio of unsaturated to saturated fatty acid of the extracted oil were not significantly (p > 0.05) affected by pomegranate seeds microwave pretreatment. Principal component analysis and agglomerative hierarchical clustering established that ‘Acco’ and ‘Wonderful’ oil extracts from microwave pretreated PS exhibited better oil yield, whilst ‘Herskawitz’ oil extracts showed higher total carotenoids content, total phenolic content, and antioxidant capacity.


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