scholarly journals Effect of Black Tea Infusion on Physicochemical Properties, Antioxidant Capacity and Microstructure of Acidified Dairy Gel during Cold Storage

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 831 ◽  
Author(s):  
Han Chen ◽  
Haotian Zheng ◽  
Margaret Anne Brennan ◽  
Wenpin Chen ◽  
Xinbo Guo ◽  
...  

The impacts of black tea infusion on physicochemical properties, antioxidant capacity and microstructure of stirred acidified dairy gel (ADG) system have not been fully explored. These impacts were studied during a 28-day cold storage (4 °C) period to explore the feasibility and technical boundaries of making acidified dairy gels in which black tea infusion (BTI) is incorporated. Reconstituted skim milks containing different proportions of BTI were acidified by GDL (glucono-δ-lactone) at 35 °C for making ADG systems. Both textural properties and structural features were characterized; antioxidant capacity was determined through three assays. They are (1) free radical scavenging ability by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; (2) ABTS [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)] assay and (3) ferric reducing antioxidant power (FRAP) assay. The microstructure of the ADGs was observed using SEM (scanning electron microscopy) and CLSM (confocal laser scanning microscopy). Results showed that BTI significantly increased the antioxidant capacity of the gel systems and the gel containing 15% BTI was as stable as the control gel in terms of syneresis rate. However lower phase stability (higher syneresis rate) was observed in the ADG with a higher portion of BTI (30% to 60%). The microstructure of the ADGs observed may explain to the phase stability and textural attributes. The results suggested that tea polyphenols (TPs) improved antioxidant capacity in all samples and the interactions between BTI and dairy components significantly altered the texture of ADGs. Such alterations were more pronounced in the samples with higher proportion of BTI (60%) and/or longer storage time (28 days).

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 910
Author(s):  
María I. Sáez ◽  
María D. Suárez ◽  
Francisco J. Alarcón ◽  
Tomás F. Martínez

This study evaluates the potential of different algae extracts (Crassiphycus corneus, Cc; Ulva ohnoi, Uo; Arthrospira platensis, Ap; Haematococcus pluvialis, Hp) as additives for the preservation of rainbow trout fillets. The extracts were prepared with different water to ethanol ratios from the four algae species. The highest ferric reducing antioxidant power (FRAP) was observed in Uo extracted in 80% ethanol. Ap aqueous extract also had considerable FRAP activity, in agreement with a high total phenolic content. Radical scavenging activity (DPPH) was higher in Cc 80% ethanol extract, in agreement with a high total carotenoid content. In fact, when the algae aqueous extracts were assayed on the fish fillets, their antioxidant activity exceeded that of ascorbic acid (ASC). All algae extracts delayed microbial growth and lipid oxidation processes in trout fillets throughout the cold storage period compared to controls, and also improved textural parameters, these effects being more evident for Ap and Hp. With respect to the color parameters, the Hp extract prevented the a* values (redness) from decreasing throughout cold storage, a key point when it comes to colored species, not least salmonids. On the other hand, the Ap extract was not as effective as the rest of treatments in avoiding a* and b* decrease throughout the storage period, and thereby the color parameters were impaired. The results obtained, together with the natural origin and the viability for large-scale cultivation, make algae extracts interesting fish preservative agents for the food industry.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Marieta Hristozkova ◽  
Liliana Gigova ◽  
Maria Geneva ◽  
Ira Stancheva ◽  
Ivanina Vasileva ◽  
...  

Abstract Mycorrhizal fungi, algae and cyanobacteria are some of the most important soil microorganisms and major components of a sustainable soil-plant system. This study presents for the first time evidence of the impact of green alga and cyanobacterium solely and in combination with arbuscular mycorrhizal fungi (AMF) on plant-antioxidant capacity. In order to provide a better understanding of the impact of AMF and soil microalgae on Ocimum basilicum L. performance, changes in the pattern and activity of the main antioxidant enzymes (AOEs), esterases and non-enzymatic antioxidants including phenols, flavonoids, ascorbate, and α-tocopherols were evaluated. The targeted inoculation of O. basilicum with AMF or algae (alone and in combination) enhanced the antioxidant capacity of the plants and the degree of stimulation varied depending on the treatment. Plants in symbiosis with AMF exhibited the highest antioxidant potential as was indicated by the enhanced functions of all studied leaf AOEs: 1.5-, 2- and more than 10-fold rises of superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione reductase (GR), respectively. The greatest increase in the total esterase activity and concentration of phenols, flavonoids and ascorbate was marked in the plants with simultaneous inoculation of mycorrhizal fungi and the green algae. 2,2-diphenyl-1-pycril-hydrazyl (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay proved the increased plant antioxidant capacity after co-colonization of green algae and mycorrhizae.


Beverages ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 2 ◽  
Author(s):  
Vassilios Raikos ◽  
He Ni ◽  
Helen Hayes ◽  
Viren Ranawana

Aqueous extracts (20% w/w) of dried berry fruits and skins were used as sources of phenolic compounds to fortify yogurt beverages. The total phenol and anthocyanin content of the reformulated yogurts were determined, and the antioxidant properties were compared to plain yogurt (C) during storage at 4 °C for a total period of four weeks. Yogurt beverages fortified with salal berry (SB) extracts contained higher amounts of phenolic compounds (>69.9 μg GAE/mL) and anthocyanins (>19.12 mg C3G/L) compared to drinks supplemented with blackcurrant pomace (BC) extract (>50.13 μg GAE/mL and >10.80 mg C3G/L respectively). Storage affected the stability of anthocyanins, whereas total phenol content remained unaffected. Yogurts with SB displayed the highest antioxidant capacity followed by samples with BC, which is attributed to the radical scavenging effect of the bioactive compounds present with antioxidant properties. The antioxidant capacity of the yogurt beverages fortified with fruit extracts was maintained during cold storage. Findings of this study indicate that SB and BC pomace can be used as functional ingredients to increase the antioxidant potential of yogurt beverages.


Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 623 ◽  
Author(s):  
Michael Zorzi ◽  
Francesco Gai ◽  
Claudio Medana ◽  
Riccardo Aigotti ◽  
Sara Morello ◽  
...  

The popularity of small berries has rapidly increased in Western countries given their antioxidant, anti-inflammatory, and antimicrobial activities and health-promoting properties. The aim of this study was to compare the fatty acid (FA) profile, phenolic compounds, and antioxidant capacity of extracts of 11 berries cultivated in the North West of Italy. Berry samples were extracted and evaluated for FA profile and total anthocyanin (TAC), total flavonoid contents (TFC), ferric-reducing antioxidant power (FRAP), and for their radical scavenging activities against 2,2′-diphenyl-1-picrylhydrazyl (DPPH•) radical. The main polyphenols of berry extracts were characterized by HPLC-DAD-UV-ESI HRMS in positive ion mode. Results showed that the highest TAC and TFC contents were recorded in black currants, blackberries, and blueberries. Maximum and minimum DPPH• radical scavenging activities, Trolox Equivalent Antioxidant Capacity, and FRAP measurements confirmed the same trend recorded for TAC and TFC values. HPLC-HRMS analyses highlight how blueberries and blackberries have the highest concentration in polyphenols. Palmitic, stearic, oleic, linoleic, α-linolenic, and γ-linolenic acids significantly differ between berries, with oleic and α-linolenic acid representing the most abundant FAs in raspberries. Among the berries investigated, results of phytochemical characterization suggest choosing black currants and blueberries as an excellent source of natural antioxidants for food and health purposes.


Author(s):  
Renuka Sehrawat ◽  
Rekha Sharma ◽  
Sonika Ahlawat ◽  
Vivek Sharma ◽  
M.S. Thakur ◽  
...  

Background: New chicken breeds are being evolved for backyard rural poultry production to overcome the slow growth, late sexual maturity and poor production of indigenous breeds. However, autochthonous poultry is epitomized for quality attributes of their products. With this in mind, the present study for the first time explored the antioxidant capacity of meat obtained from a unique Indian chicken, Kadaknath and a synthetic breed of poultry, Jabalpur colour (JBC). Methods: During the period 2018-2020, breast and thigh meat were collected from chickens (n=20/ group) at their commercial slaughter age (20 weeks). Meat extract was used for qualitative evaluation. Antioxidant activity was explored using five well established in vitro methods testing for different antioxidant mechanisms. Result: Both, Kadaknath and JBC meat was proteinaceous with higher protein concentration (g/100 g of wet weight) in the breast (Kadaknath, 25.21±0.31 and JBC, 25.65±0.39) than the thigh (Kadaknath, 19.98±0.29 and JBC, 19.04±0.23). Both the groups exhibited antioxidant capacity in all the assays. They showed good radical scavenging for ABTS and DPPH free radicals. Superiority of Kadaknath meat was ascertained unequivocally by the three assays viz. Ferric reducing antioxidant power (FRAP), lipid oxidation inhibition (TBARS) and metal chelating capacity. FRAP values (mM Fe2+/g of tissue) were 26.97±0.37 and 33.85±0.47 (Kadaknath) and 22.84±0.25 and 26.82±0.36 (JBC) for breast and thigh, respectively. Similarly, Kadaknath meat was more potent (% inhibition) iron chelator (breast, 62.71±0.99 and thigh, 75.07±0.98) in comparison to the JBC (breast, 46.30±2.36 and thigh, 63.12±1.87). Breast meat had better scavenging capacity than the thigh except in FRAP and metal chelating assays. Results provide insight into the antioxidant potential of backyard poultry germplasm thus, laying foundation for developing marketing strategies targeting consumers interested in nutritional quality, animal welfare and environmental sustainability. Furthermore, baseline data has been generated for studying medicinal properties attributed to the black chicken meat of Kadaknath.


2013 ◽  
Vol 76 (7) ◽  
pp. 1218-1225 ◽  
Author(s):  
YOLANDA RUIZ-NAVAJAS ◽  
MANUEL VIUDA-MARTOS ◽  
ESTHER SENDRA ◽  
JOSÉ A. PEREZ-ALVAREZ ◽  
JUANA FERNÁNDEZ-LÓPEZ

The aim of this work was to determine (i) the antioxidant capacity of Thymus moroderi, Thymus piperella, Santolina chamaecyparissus, and Sideritis angustifolia essential oils (EOs) by means of four different antioxidant tests (the 2,2′-diphenyl-1-picrylhydrazyl radical scavenging method, the ferrous ion–chelating ability assay, the ferric reducing antioxidant power test, and the thiobarbituric acid reactive species test) and (ii) the antifungal activity against molds and yeast of these EOs by the agar dilution and the microdilution methods. T. piperella EO showed the lowest 50% inhibitory concentration by the 2,2′-diphenyl-1-picrylhydrazyl radical scavenging method (9.30 mg/ml) and by the thiobarbituric acid reactive species test (6.30 mg/ml) and the highest value by the ferric reducing antioxidant power test (2.64 Trolox equivalent antioxidant capacity), while S. chamaecyparissus showed the lowest 50% inhibitory concentration in the ferrous ion–chelating ability assay (3.94 mg/ml). All EOs had a substantial inhibitory effect on all assayed yeast strains. S. angustifolia EO had the lowest MICs (2.5 μl/ml) for the yeasts Saccharomyces cerevisiae, Debaryomyces hansenii, Rhodotorula mucilaginosa, and Pichia carsonii. As regards antifungal activity, S. angustifolia EO at high concentrations was the most effective EO in reducing the growth of Alternaria alternata, Penicillium chrysogenum, and Mucor racemosus, while S. chamaecyparissus was the best inhibitor of the molds Aspergillus flavus and Mucor circinelloides. The results obtained in this study suggest the possibility of using these essential oils as natural antioxidant food preservatives.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Sathsara T. Deyalage ◽  
Indira Wickramasinghe ◽  
Nimesha Amarasinghe ◽  
Gayan Thilakarathna

Green leafy vegetables (GLVs) are abundant in bioactive compounds and constitute a crucial part of a balanced diet. Sri Lankan green leafy vegetables which are edible and available for consumption have not been thoroughly investigated, whilst their consumption can deflate the risk of arising several degenerative diseases, such as cancer and cardiovascular diseases. The present study was aimed at evaluating the antioxidant capacities of the leafy vegetables, Gymnema lactiferum (Kurignan), Wattakaka volubilis (Aguna), and Argyreia populifolia (Girithilla), with different thermal treatments (70°C, 120°C, and 170°C) which are used in domestic cooking processes. Heat treatments significantly affect the antioxidant capacity and polyphenolic content of most vegetables analyzed, either increasing or decreasing the concentration of these compounds. In the presence of thermal treatments, Gymnema lactiferum (14.52-20.28 mg GAE/g DW) and Wattakaka volubilis (19.75-27.13 mg GAE/g DW) showed a significantly higher ( p < 0.05 ) total phenolic content. The temperature treatment did not alter the ABTS radical scavenging activity in Gymnema lactiferum. In contrast, an increment of ferric reducing antioxidant power (41.26-54.85 mg TE/g DW) and DPPH radical scavenging activity (0.11-0.26 mg TE/g DW) was observed. Wattakaka volubilis treated at 170°C appeared to have a significantly higher amount ( 104.93 ± 1.41   mg TE/g DW) of ferric reducing antioxidant power compared to its raw form. All cooking processes with their corresponding thermal treatments caused a significantly lower ( p < 0 ) amount of antioxidant capacity in Argyreia populifolia.


2013 ◽  
Vol 12 (2) ◽  
pp. 19 ◽  
Author(s):  
Masturah Markom ◽  
Norsyamimi Hassim ◽  
Nurina Anuar ◽  
Syarul Nataqain Baharum

This study evaluated the biological activity (antioxidant assay) of Polygonum minus extracted using Supercritical Fluid Extraction (SFE) added with different types of co-solvents. The seven co-solvents employed were water, methanol, ethanol, 50% methanol, 50% ethanol, 70% methanol and 70% ethanol for selection of the best co-solvent prior to optimization of SFE. 70% methanol produced the highest total yield of extract (33.1%) compared to other co-solvents. The antioxidant capacity was then evaluated using four different assays: the total phenolic content (TP), the total flavonoid content (TF), the ferric reducing/antioxidant power (FRAP) and the free radical-scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The highest TP and TF were from 70% methanol extract (11.2 ± 0.15 mg GAE/g sample (mg GAE/g) and 11.9 ± 0.03 mg CAE/g sample (mg CEQ/g) respectively). 70% metanol extract also showed the highest FRAP value (346.7 ± 0.66 µmol Fe (II)/g sample) and the highest percentage of DPPH radical inhibition was also shown by 70% methanol extract (88.7 ± 0.40%). There was a positive correlation between the antioxidant capacity (FRAP and DPPH) with those of TP and TF contents. Therefore, the best co-solvent chosen for further optimization of SFE is 70% methanol.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ruth Edwige Kemadjou Dibacto ◽  
Boris Ronald Tonou Tchuente ◽  
Maxwell Wandji Nguedjo ◽  
Yves Martial Tongue Tientcheu ◽  
Emilienne Carine Nyobe ◽  
...  

Fruit peels are increasingly being used as functional foods nowadays. Peelings of twelve varieties of Persea americana fruits consumed in Cameroon were investigated for their phenolic compounds (polyphenols and flavonoids) using three solvents systems, water, ethanol: water (50 : 50 v / v ), and ethanol, and antioxidant activity using total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging methods. Total polyphenol, flavonoids, and antioxidant potential of the peels significantly varied with P. americana variety and also with the extraction solvents in the order ethanol > ethanol: water > water. Total phenolic content varied from 2407 (Fuerte florid) to 673 (Semil) mg GAE/g DM, respectively, while flavonoids varied from 986 to 119 mg QE/g DM for Fuerte florid and Hickson varieties, respectively. TAC, respectively, varied between 132.87 and 126.85 mg AAE/g DM with Hass and Semil varieties, respectively. The highest DPPH scavenging capacity was recorded for the ethanolic extract with Lula (86.33%) and the least for the aqueous extract with the Semil (30.11%) variety. With FRAP, the highest capacity was obtained with hydroethanolic extract of Fuerte florid (0.43 mg AAE/g DM) and the least for aqueous extract with the Semil (0.269 mg AAE/g DM) variety. In conclusion, varieties of avocado peels are a good source of antioxidants. Solvent extraction significantly affected the concentration of bioactive compounds but not the potency of the antioxidants. A weakly positive correlation but not significant between the quantity of polyphenol, flavonoid, and antioxidant capacity of avocado peelings was obtained in this study.


HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1711-1715 ◽  
Author(s):  
Attila Hegedűs ◽  
Emőke Balogh ◽  
Rita Engel ◽  
Béla Zoltan Sipos ◽  
János Papp ◽  
...  

Fruits of four berry species (strawberry, raspberry, red and black currants) were compared in their elemental composition (Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn) and redox parameters involving total phenol content (TPC), ferric reducing ability (FRAP), 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and total radical scavenger activity (TRSA). Berry cultivars contained significantly higher (P ≤ 0.05) amounts of most detected elements as compared with apple with many maximum elemental values demonstrated by the black currant ‘Otelo’. Black currant also had the greatest antioxidant capacity as demonstrated through all conducted assays. The results obtained through FRAP, TPC, and TRSA assays were closely correlated, whereas TRSA and DPPH varied independently. Our study provides valuable information on the antioxidant capacity of several berry species grown in Hungary and highlights the crucial influence of cultivar on elemental content and antioxidant power of berry fruits. This study demonstrated the ability to select berry cultivars for specific nutritional purposes or assign parental lines in functional breeding programs.


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