scholarly journals Anthocyanin Recovery from Grape by-Products by Combining Ohmic Heating with Food-Grade Solvents: Phenolic Composition, Antioxidant, and Antimicrobial Properties

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3838
Author(s):  
Marta Coelho ◽  
Sara Silva ◽  
Eduardo Costa ◽  
Ricardo N. Pereira ◽  
António Sebastião Rodrigues ◽  
...  

Usually, wine-making by-products are discarded, presenting a significant environmental impact. However, they can be used as a source of bioactive compounds. Moreover, consumers’ increasing demand for naturally nutritious and healthy products requires new formulations and food product improvement, together with sustainable, environmentally friendly extraction methods. Thus, this work aimed to compare ohmic heating (OH) with conventional methodology (CONV), using food-grade solvents, mainly water, compared to standard methanol extraction of anthocyanins. No significant differences were found between the CONV and OH for total phenolic compounds, which were 2.84 ± 0.037 and 3.28 ± 0.46 mg/g DW gallic acid equivalent, respectively. The same tendency was found for antioxidant capacity, where CONV and OH presented values of 2.02 ± 0.007 g/100 g and 2.34 ± 0.066 g/100 g ascorbic acid equivalent, respectively. The major anthocyanins identified were malvidin-3-O-acetylglucoside, delphinidin-3-O-glucoside, petunidine-3-O-glucoside, cyanidin-3-O-glucoside, and peonidine-3-O-glucoside. These extracts displayed antimicrobial potential against microorganisms such as Yersinia enterocolitica, Pseudomonas aeruginosa, Salmonella enteritidis, methicillin-sensitive Staphylococcus aureus, a methicillin-resistant Staph. aureus (MRSA), and Bacillus cereus. In conclusion, OH provides similar recovery yields with reduced treatment times, less energy consumption, and no need for organic solvents (green extraction routes). Thus, OH combined with water and citric acid allows a safe anthocyanin extraction from grape by-products, thus avoiding the use of toxic solvents such as methanol, and with high biological potential, including antimicrobial and antioxidant activity.

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Veronica Santarelli ◽  
Lilia Neri ◽  
Katya Carbone ◽  
Valentina Macchioni ◽  
Paola Pittia

This study investigated the use of conventional and innovative extraction methods to produce food-grade hop extracts with high antioxidant capacity and content in bioactive compounds. Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60 °C; innovative extractions were performed using two ultrasound systems, a laboratory bath (US) and a high-power ultrasound bath (HPUS), and a high-pressure industrial process. For CONV, US, and HPUS extractions the effect of the extraction time was also tested. Experimental results showed that extraction method, temperature, and time affect to a different extent the phenolic profile and have a significant effect (p < 0.05) on the total phenolic content, total flavonoid content, antiradical capacity (ABTS), chlorophyll α, and total carotenoids content. Overall, US and CONV 60 °C extractions showed the highest extraction efficiency for almost all the investigated compounds, however, the extraction method and time to be used strongly depends on the target compounds to extract.


2009 ◽  
Vol 15 (5) ◽  
pp. 503-512 ◽  
Author(s):  
H. Yildiz ◽  
H. Bozkurt ◽  
F. Icier

Ohmic heating is an alternative fast-heating method especially for liquid foods. In this study, pomegranate juice samples, prepared by two different extraction methods, were heated ohmically by matching the same thermal history, with that of the conventional method. The ohmic heating application was conducted by changing the voltage gradient (10—40 V/cm) at 50 Hz. The samples were heated from 20 ° C to 90°C and held at 90 °C for different treatment times (0, 3, 6, 9 or 12 min). Although rheological properties, color, and total phenolic content (TPC) values changed at the initial heating up period, there were no significant changes during holding period (p < 0.05). Non-Newtonian (power law) rheology model had higher regression coefficient than Newtonian model, and the extraction method affected the consistency of pomegranate juice samples (p < 0.05). Color values of juice extracted from arils (APJ) was better than that of juice extracted from whole fruits (PPJ), as PPJ contained higher amount of TPC (p < 0.05). Since the heating method did not affect the rheological properties, color, and TPC values, it could be said that there was no electrical effect rather than thermal effects during ohmic heating of pomegranate juice. Ohmic heating could be recommended as an alternative fast-heating method for fruit juices.


Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 177
Author(s):  
Nicolas Joly ◽  
Kaies Souidi ◽  
David Depraetere ◽  
Daniel Wils ◽  
Patrick Martin

Total phenolic compounds (TPC) and the chlorogenic acids content of potato by-product extracts of two hydro alcoholic solvents (methanol, ethanol) and two extraction methods (maceration and heating-assisted extraction) were studied. The content of TPC in the extracts was determined spectrometrically according to the Folin–Ciocalteu procedure and calculated as chlorogenic acid equivalents. Soluble phenolic acids, especially the chlorogenic acids, were performed by HPLC. The antioxidant activity of potato by-product extracts was determined by using the total oxygen radical absorbance capacity (ORAC) method. The highest content of TPC was found in raw and lyophilized red waters when using ethanol as a solvent around 57 mg/g fresh weight. Heating-assisted extraction enhances this quantitative increasing. At the given operating conditions, unpeeled potato samples exhibit a higher TPC than peeled ones, showing that TPC are accumulated in skin tissue. The greatest amount of chlorogenic acid (Caffeoyl-Quinic Acids, 3, 4, 5 CQA), mainly the 5-CQA (870 ± 39.66 µg/g WM for wet matter versus DM dry matter), was obtained in the pellets and lyophilized fresh peels (skin vs. flesh). In addition, the greatest amounts of chlorogenic acids were found when potato peels were extracted with methanol. Heating-assisted extraction improved the chlorogenic acid concentration of the potato peel extracts. The total ORAC amounts recorded in the different potato fractions varied between 1500 and 1650 µM TE/g. They were higher than those of some fruits, vegetables, nuts, cereals, and sweet potato cultivar. The good correlation coefficient found between TPC, chlorogenic acids determination, and the ORAC capacity indicates that the TPC can be used as a good indicator of the antioxidant capacity of potato by-products.


Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 489 ◽  
Author(s):  
Nabeelah Bibi Sadeer ◽  
Gabriele Rocchetti ◽  
Biancamaria Senizza ◽  
Domenico Montesano ◽  
Gokhan Zengin ◽  
...  

Currently, there is a renewed interest towards the development of plant-based pharmacophores. In this work, 16 extracts prepared from the leaves, twigs, roots and fruits of a hydro-halophyte, Rhizophora mucronata Lam. (Family: Rhizophoraceae), were studied for possible antioxidant activity and the phenolic profiles established. Thereafter, enzymatic inhibitory activities (α-amylase, α-glucosidase, tyrosinase, acetyl- (AChE), butyrylcholinesterase (BChE), lipase, and elastase) were assessed. The total phenolic, flavonoid, phenolic acid, tannin, flavanol and triterpenoid content were estimated using standard assays. An untargeted metabolomics-based approach, based on ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS) followed by multivariate statistics, was then used to comprehensively profile and describe the phenolics present. UHPLC-QTOF-MS allowed for putatively annotating 104 phenolic acids, 103 flavonols, 94 flavones, 71 anthocyanins, 66 tyrosols, 29 lignans, 15 alkylphenols and 10 stilbenes in the extracts. Nine strains (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Methicillin-resistant Staphylococcus aureus (MRSA), Salmonella enteritidis, Sarcina lutea, Proteus mirabilis, Bacillus cereus and Candida albicans) were then used to investigate the antimicrobial properties. The methanolic twig extract exhibited significant reducing potential towards Cu (II)/Cu (I) and Fe (III)/Fe (II) (1336.88 ± 15.70 and 710.18 ± 21.04 mg TE/g, respectively) and was the most potent DPPH radical scavenger (807.07 ± 6.83 mg TE/g). Additionally, the methanolic twig extract showed significant inhibition against most targeted enzymes. Anti-microbial results showed that all extracts were active against MRSA. Multivariate analysis demonstrated that the phenolic profile of ethyl acetate extracts and leaves were the two most discriminative parameters in terms of solvents and organs, respectively. The present findings indicated that R. mucronata may be further explored for the management/prevention of oxidative stress, neurodegenerative complications and hyperpigmentation.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 570
Author(s):  
Elisabete M. C. Alexandre ◽  
Marta C. Coelho ◽  
Kardelen Ozcan ◽  
Carlos A. Pinto ◽  
José A. Teixeira ◽  
...  

Phenolic compounds are important bioactive compounds identified in prickly pear peel that have important antioxidant and antimicrobial properties. However, conventional thermal extraction methods may reduce their bioactivity, and technologies such as high pressure (HP) and ohmic heating (OH) may help preserve them. In this study, both technologies were analyzed, individually and combined (250/500 MPa; 40/70 °C; ethanol concentration 30/70%), and compared with Soxhlet with regard to total phenolics, flavonoids, and carotenoids as well as antioxidant (ABTS, DPPH, ORAC), DNA pro-oxidant, and antimicrobial (inhibition halos, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), growth curves, and viable cells) activities of prickly pear peel extracts. Total phenolics extracted by each technology increased 103% (OH) and 98% (HP) with regard to Soxhlet, but the contents of total flavonoids and carotenoids were similar. Antioxidant activity increased with HP and OH (between 35% and 63%), and OH (70 °C) did not induce DNA degradation. The phenolic compound present in higher amounts was piscidic acid, followed by eucomic acid and citrate. In general, their extraction was significantly favored by HP and OH. Antimicrobial activity against 7 types of bacteria showed effective results only against S. aureus, S. enteritidis, and B. cereus. No synergetic or additive effect was observed for HP/OH.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 783
Author(s):  
Alessio Saviane ◽  
Luca Tassoni ◽  
Daniele Naviglio ◽  
Daniela Lupi ◽  
Sara Savoldelli ◽  
...  

The aim of this work was to develop processing methods that safeguard the quality and antimicrobial properties of H. illucens and B. mori oils. We adopted a vegetable diet for both insects: leftover vegetables and fruit for H. illucens and mulberry leaves for B. mori. First, alternative techniques to obtain a good oil extraction yield from the dried biomass of H. illucens larvae were tested. Traditional pressing resulted to be the best system to maximize the oil yield and it was successfully applied to B. mori pupae. Oil quality resulted comparable to that obtained with other extraction methods described in the literature. In the case of B. mori pupae, different treatments and preservation periods were investigated to evaluate their influence on the oil composition and quality. Interestingly, agar diffusion assays demonstrated the sensitivity of Gram-positive Bacillus subtilis and Staphylococcus aureus to H. illucens and B. mori derived oils, whereas the growth of Gram-negative Pseudomonas aeruginosa and Escherichia coli was not affected. This study confirms that fat and other active compounds of the oil extracted by hot pressing could represent effective antimicrobials against bacteria, a relevant result if we consider that they are by-products of the protein extraction process in the feed industry.


Author(s):  
Mercy C. Ruto ◽  
Christine M. Ngugi ◽  
Patrick G. Kareru ◽  
Kipyegon Cheruiyot ◽  
Sylvester O. Rechab ◽  
...  

Background: Natural phytoconstituents produced by plants for their sustenance have been reported to reduce disease.Objectives: This study determined the phytoconstituents, antioxidant and antimicrobial activity of crude methanolic extracts of Entada leptostachya and Prosopis juliflora extracts.Methodology: Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl and β-carotene assays; the total phenolic and flavonoid were estimated using Folin–Ciocalteau and aluminium chloride, whereas antimicrobial activity was determined using the zone of inhibition method.Results: Screening of the extracts revealed the presence of terpenoids, flavonoids, saponins and phenols. Fourier transform infrared spectra of the extracts revealed presence of hydrogen bonded –OH functional group. E. leptostachya barks had the highest antioxidant activity followed by P. juliflora roots, E. leptostachya roots and P. juliflora leaves [μg/mL]. Prosopis juliflora (roots) had the highest bleaching effect, whereas E. leptostachya (barks) had the lowest bleaching effect. The total flavonoids were determined to be 0.15 ± 0.02 mg/g, 1.18 ± 0.18 mg/g, 0.39 ± 0.05 mg/g and 0.64 ± 0.03 mg/g for E. leptostachya roots, E. leptostachya barks, P. juliflora leaves and P. juliflora roots extracts, respectively. The total phenols were determined to be 0.93 ± 0.18 mg/g, 2.69 ± 0.41 mg/g, 0.62 ± 0.08 mg/g and 0.62 ± 0.08 mg/g for E. leptostachya roots, E. leptostachya barks, P. juliflora roots and P. juliflora leaves extracts. All plant extracts exhibited moderate activity against the growth of selected microorganisms.Conclusion: Antimicrobial and antioxidant activity of the two plants was as a result of secondary metabolites found in the crude extracts.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Ayeza Naeem ◽  
Tanveer Abbas ◽  
Tahira Mohsin Ali ◽  
Abid Hasnain

Lipid fraction from four different culinary condiments namely black seed (Nigella sativa), fennel seeds (Foeniculum vulgare), bay leaf (Laurus nobilis) and coriander seeds (Coriandrum sativum) were investigated for total phenolic content, antioxidant activity, total flavonoid content, total flavonol content and antibacterial attributes. Antimicrobial properties were determined against food-borne bacteria through agar well diffusion, drop agar diffusion, macrobroth dilution with simultaneous determination of their minimum inhibitory concentrations and changes in cellular morphology was analyzed through Scanning electron microscopy. Generally, ethanolic lipid fractions were more effective bioactively as compared to methanolic LFs. Parallel results were obtained for antibacterial activities with the highest antibacterial activities exhibited by ethanolic LFs. The results positively support the use of these lipid fractions in generating new systems to inhibit bacterial growth, extend the shelf life and enhance the safety of the packaged food product. The examined oils can also be used for therapeutic purposes.


2021 ◽  
pp. 108201322098310
Author(s):  
Noelia Castillejo ◽  
Ginés Benito Martínez-Hernández ◽  
Francisco Artés-Hernández

The effect of revalorized Bimi leaves (B) and/or mustard (M) addition, as supplementary ingredients, to develop an innovative kale (K) pesto sauce was studied. Microbial, physicochemical (color, total soluble solids content -SSC-, pH and titratable acidity –TA-) and sensory quality were studied during 20 days at 5 °C. Bioactive compounds changes (total phenolics, total antioxidant capacity and glucoraphanin contents) were also monitored throughout storage. The high TA and pH changes in the last 6 days of storage were avoided in the K+B pesto when adding mustard, due to the antimicrobial properties of this brassica seed. SSC was increased when B + M were added to the K pesto, which positively masked the kale-typical bitterness. Mustard addition hardly change yellowness of the K pesto, being not detected in the sensory analyses, showing K+B+M pesto the lowest color differences after 20 days of shelf life. The addition of Bimi leaves to the K pesto enhanced its phenolic content while mustard addition did not negatively affect such total antioxidant compounds content. Finally, mustard addition effectively aimed to glucoraphanin conversion to its bioactive products. Conclusively, an innovative kale pesto supplemented with Bimi by-products was hereby developed, being its overall quality well preserved up to 20 days at 5 °C due to the mustard addition.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Miedzianka ◽  
Katarzyna Drzymała ◽  
Agnieszka Nemś ◽  
Agnieszka Kita

AbstractGluten-free flours are interesting alternative to wheat flours. They could be by-products of oilseed processing, characterized by high content of bioactive compounds. Therefore the aim of the study was to determine the antioxidant, antimicrobial properties, amino acid and fatty acid profile of flours obtained as by-products from the oil industry. The highest total polyphenol content and antioxidant activity was found to have evening primrose flour. The widest spectrum of microbial growth inhibition was indicated for corn germ extract which showed no antimicrobial activity only against Bacillus subtilis. The highest protein content was found in pumpkin, peanut and almond flours (more than 50 g/100 g). The major abundant amino acids in all the analysed oilseed cake flours were aspartic acid, glutamic acid and arginine. The analysed gluten-free flours were found to be a good source of polyunsaturated fatty acids (PUFAs), which comprised mainly linoleic acid and α-linolenic acid, whereas the best source of PUFAs was evening primrose flour. The results suggest that the cold-pressed seed flours possess valuable chemical composition and may be considered for improvement of the nutritional properties of food products.


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