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THE EFFECT OF PICKLING ON TOTAL PHENOLIC CONTENTS AND ANTIOXIDANT ACTIVITY OF 10 VEGETABLES
Abstract
Epidemiological evidence suggests the critical role of vegetable consumption in preventing chronic degener-ative diseases. Considering that pickle is a widely consumption type of vegetable in Turkish diet the objective of the present study was to assess the total phenol content and antioxidant capacity of pickled vegetables. For this purpose total antioxidant capacity of 10 fresh and pickled vegetables was analysed by DPPH (2,20-diphe-nyl-1-picryl hydrazyl) radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) methods and total phenolic content (TPC) using Folin–Cio-calteu reagent. Following the pickling in 15 th day there was a significant (P<0.05) decrease in TPC of all vegetables , in contrast this TPC increased significantly after 30 th day. Also at 60 th day of pickling the TEAC values of all vegetables are increased significantly (P<0.05), but DPPH values of green pepper, cauliflower, cucumber and sneak melon decreased compared with fresh state. Our findings suggest that, pickling process is relatively a good method for the preservation of phenolic acids in vegetables, and most of the antioxidant capacities remained after 30 th day of fermentation.
... Still, after three months of storage, it decreased to 475.3 mg GAE/g, not showing a statistically significant difference compared to the product before pickling. Sayin and Alkan [31] also pointed to a decrease in polyphenol content during the storage of pickled vegetables. Assessing the effect of pickling on the total content of polyphenolic compounds in ten vegetables, they noted a decrease in the amount of polyphenols in pickled vegetables during 60-day storage. ...
... Park et al. [30] showed an increase in antioxidant activity during mustard leaf kimchi pickling, followed by a decrease. Studies conducted on pickled products of plant origin showed that fermentation increased the antioxidant activity of blueberries, mulberries, and apple pomace [31]. Kapusta-Duch et al. [32] found a decrease in the ability to absorb free radicals during the 4-month storage of sauerkraut. ...
... The release of simple phenolic compounds may cause changes in the ability to absorb free radicals by pickled stone fruits due to acidic and enzymatic hydrolysis of polymerized phenolic compounds. In addition, lactic acid bacteria possess enzymatic and non-enzymatic antioxidant mechanisms and minimize the production of reactive oxygen species to levels that are harmless to the cell [31]. ...
... Antioxidant activity is very important properties of food and one of factors that make functional properties of food. Fermentation is reported to increase antioxidant properties of fermented vegetables (Sayin & Alkan, 2015;Lee et al., 2016;Wang et al., 2021). Antioxidant activity was found either in the fermentation broth (Kim et al., 2003) or solid part (Wang et al., 2021;Lee et al., 2016) of the fermentation product. ...
Fermented vegetable has become more popular as part of daily diet due to their increased shelf life and, more importantly, their beneficial effect for health. Climbing swamp fern (Sthenochlaena palustris) is an edible plant that known has medicinal properties. Fermentation can improve functionality of food, and therefore in the present study we prepare fermented fern and examine antioxidant activity, total phenolic and flavonoid content of the fermentation broth. The fronds of fern were collected from local farmer and fermented with different salt concentration (2, 4, 6% w/w), addition of exogenous lactic acid bacteria (none vs Lactobacillus plantarum) and time of fermentation (72 vs 144 hours). The experiment was performed using completely randomized design with factorial design approach. Broth formed during fermentation was collected and examined for their total flavonoid content (TFC), total phenolic content (TPC) and antioxidant activity, measured as percentage of DPPH inhibition. The result indicated that salt has significant effect on TFC, while all the three factors have significant effect TPC and DPPH inhibition. The highest TFC was observed when lowest salt was used, and the highest TPC was observed when the lowest salt concentration was used with the addition of L. plantarum and the lowest fermentation time. While the highest antioxidant activity was observed when the highest concentration of salt used with the addition of L. plantarum and the lowest fermentation time. TPC has significant and moderate correlation with TFC and DPPH inhibition, while TPC and TFC indicate no significant and no correlation. Further investigation is required to examine antioxidant compounds other than polyphenol and flavonoid in the fermentation broth. Furthermore, the solid fraction of the fermented fern fronds needs to be examined for its antioxidant property.
... Sayin and Alkan (2015) observed similar changes upon pickling 10 vegetables over a period of 60 days. 56 As carried out in this study, brief blanching treatments prior to brining can improve the antioxidative potentials of vegetables. In a study by , the concentrations of chlorogenic, neochlorogenic, cryptochlorogenic and caffeoylmalic acids were elevated upon blanching of Chinese cabbage (Brassica rapa L. subsp. ...
Wild edible vegetables (WEVs) are integral for sustained nutrition and livelihood of forest-dwelling tribal communities. Shelf-life enhancement of WEVs is crucial to overcome their perishability and ensure availability. Chemical preservatives are detrimental to their commercial ‘organic’ status, and modern processing technologies are often challenging to be implemented by the marginalized farmers. In this study, four nutritionally important WEVs popularly cultivated, consumed and marketed in the hilly, forest-covered state of Mizoram, India, namely, Solanum aethiopicum (ST), Solanum torvum (TP), Solanum anguivi (TT) and Leucaena leucocephala (JZ), were subjected to brining and drying to enhance their shelf-lives. The drying method was standardized using response surface methodology at 80 °C and 540 minutes, obtaining the lowest moisture content with the highest total phenolic content (TPC) and DPPH radical scavenging activity (DRSA). A strong positive correlation was obtained between TPC and DRSA values of ST (R = 0.738), TP (R = 0.760), TT (R = 0.977) and JZ (R = 0.935). Both brined bottled and dried vacuum-packaged samples were studied over 35 days of storage. Packaged dried samples were stored at room temperature (RT) and under refrigeration (RF). Brined WEVs showed a decrease in moisture and carbohydrate contents. Microbial conversion of sugars to lactic acid was evidenced by lowering pH to below 3.0. Bacterial activity also markedly enhanced TPC, flavonoids and DRSA values by causing free phenolics release and their structural transformation. However, overall microbial population in terms of aerobic coliform bacteria and fungal species were efficiently retarded up to more than 65% by the two treatments. Vacuum-packaged RF samples exhibited lowered microbial metabolism. Pigment degeneration and tissue structure changes were indicated by changed color and hardness. Dried tissue brittleness enhanced the extractability of bioactive compounds. Vacuum-packaging improved antioxidant retention in the processed WEVs.
... Heterofermentative LAB can reach 9 log10 CFU/mL during the first week of fermentation and then the number decreases because it replaced by homofermentative microorganisms that are more tolerant to acid (Breidt et al., 2013). The fermentation process can increase the effect on the level of bioactive components and antioxidant capacity of vegetables, the length of the fermentation process can influence the antioxidant content of pickles, and generally can be maintained during the 30 day fermentation process (Sayin & Alkan, 2015). ...
Sauerkraut is a typical German food made from thinly sliced cabbage. Sauerkraut is a fermeted product that can give a distinctive taste. Sugar is an ingredient that can be added in, that sugar can trigger the growth of lactic acid bacteria. Indonesian people like food with a spicy sensation from chilies, chillies here contain vitamin C which functions as an antioxidant that is good for the body and is able to increase endurance. This study aims to calculate the total lactic acid bacteria contained in sauerkraut with the addition of chilies and sugar. Dilution of 1 ml sample into 9 ml physiological NaCl solution from 10 -1 to 10 -8 dilutions was carried out, then inoculated into MRS Agar using the pour plate method. Incubated in room temperature for 48 hours. The growing colonies of lactic acid bacteria were then observed based on colony morphology and counting the total growing lactic acid bacteria. The results of the research can be concluded that there was an increase in the number of lactic acid bacteria in sauerkraut with the addition of chili and 10% granulated sugar with a bacterial density average is 88.667 x 108 CFU/mL.
... The highest significant value of DPPH was found with the RJC treatment followed by RJC5 then RJC1 treatments, whilst the RPM treatment possessed a significant increment in DPPH value followed by RPT then RPC treatments. Moreover, the finding of the present study displays that adding garlic significantly enhanced the DPPH value when compared with the control sample of both RR and BR treatments, this is because garlic had the strongest antioxidant capacity as reported by Sayin and Alkan (2015). Sawicki and Wiczkowski (2018) reported that, there is a decrement in the rate of betalains loss during boiling and fermentation of the unpeeled red beet and so the unpeel step for the red beetroot enhances the DPPH percent as well as the antioxidant effect. ...
... Rapid acidification during pickling is desirable because low pH inhibits growth of undesirable microorganisms [8,17]. Salt in pickling inhibits growth of undesirable microorganisms and induces plasmolysis in plant cells which leads to the release of water, minerals and nutrients needed for LAB growth [8,17,18]. Therefore, a combination of sugar and dry salt provides an ideal approach for pickling nakati. ...
Solanum aethiopicum is a nutrient rich green leafy vegetable whose utilisation is limited by its short shelf life. Although refrigeration and freezing are effective methods to preserve vegetables, these methods may not be available and affordable in resource-limited settings. A viable alternative is pickling, which is a cost effective and easy to apply method. In this study, nakati leaves were fermented in brine with 3% dry salt and 2% sugar at 25°C for 14 days. The fermentation was monitored at intervals by enumerating lactic acid bacteria (LAB), coliforms and fungi as well as measuring the brine pH. Sensory evaluation (n=30) was carried out to assess the acceptability of the vegetables. Shelf stability was evaluated for three weeks. The results showed that lactic acid bacteria increased significantly (P < .001) from 2.06 log cfu/ml to 8.2 log cfu/ml during fermentation. Coliforms and fungi reduced from 5.5 log cfu/ml and 1.5 log cfu/ml to undetectable levels within 8 and 6 days of fermentation, respectively. The brine pH decreased from 5.87 at day 0 to 3.35 after 14 days of fermentation (P < .001). Pickled nakati had lower consumer acceptability scores (P < Short Research Article 67 .001) than fresh nakati. The nakati remained stable during the three weeks of storage. Therefore, pickling offers a potentially viable preservation method that can be adopted for green leafy vegetables.
Delving into the intricate role of phytonutrients is paramount to effectively preventing and treating chronic diseases. Phytonutrients are “plant-based nutrients” that positively affect human health. Phytonutrients perform primary therapeutic functions in the management and treatment of various diseases. It is reported that different types of pathogenesis occur due to the excessive production of oxidants (reactive nitrogen species and reactive oxygen species). The literature shows that a higher intake of fruits, vegetables, and other plant-based food is inversely related to treating different chronic diseases. Due to many phytonutrients (antioxidants) in fruits, vegetables, and other medicinal plants, they are considered major therapeutic agents for various diseases. The main purpose of this review is to summarize the major phytonutrients involved in preventing and treating diseases. Fourteen major phytonutrients are discussed in this review, such as polyphenols, anthocyanin, resveratrol, phytosterol (stigmasterol), flavonoids, isoflavonoids, limonoids, terpenoids, carotenoids, lycopene, quercetin, phytoestrogens, glucosinolates, and probiotics, which are well-known for their beneficial effects on the human body and treatment of different pathological conditions. It is concluded that phytonutrients play a major role in the prevention and treatment of diabetes mellitus, obesity, hypertension, cardiovascular disorders, other types of cancers, neurological disorders, age-related diseases, and inflammatory disorders and are also involved in various biological activities.
Preservative fruits have gained popularity in recent years as part of food consumption, but their benefits towards human health are not known. This study compared total phenolic (TPC), total flavonoid (TFC), β-carotene, lycopene, ascorbic acid (AA) contents and antioxidant properties between fresh and pickled papaya. The results indicated that mean TPC (mg gallic acid equivalent/100 g dry samples), TFC (mg rutin equivalent/100 g dry samples), β-carotene (μg/100 g edible portions), lycopene (μg/100 g edible portions) and AA content (mg/100 g edible portions) were higher in fresh papaya (141.66 ± 11.71; 57.80 ± 2.11; 793.83 ± 5.47; 779.69 ± 5.55; 70.37 ± 0.65) as compared to pickled form. Antioxidant activity (%) measured by DPPH and β-Carotene-Linoleate bleaching method was higher in fresh papaya (56.83 ± 4.68; 77.56 ± 1.40). Total phenolic, total flavonoid, ascorbic acid, beta carotene and lycopene were strongly correlated with antioxidant activity and scavenging activity (0.905 ≤ r ≤ 1.00) indicating that were important contributors to antioxidant properties in papaya extracts. The pickling process of papaya caused a significant decrease in their antioxidant component and activity.
Epidemiological evidence suggests that consumption of vegetables can prevent degenerative diseases caused by oxidative stress. Considering scanty data available on antioxidant activity (AOA) of roots, tubers and vegetables commonly consumed in India, the objective of the present study was to assess their AOA and relate it to their total phenolic content. AOA was assessed in vegetables (n=19) and roots/tubers (n=10) by DPPH (2,2′-diphenyl-1-picryl hydrazyl) scavenging activity and FRAP (ferric reducing antioxidant power) methods and the total phenolic content (TPC) using Folin–Ciocalteu reagent. Although AOA as well as TPC showed wide variation among roots, tubers and vegetables studied. AOA (both DPPH and FRAP) was significantly correlated with TPC among all the foods studied, with the correlation coefficient (r) values being 0.76 and 0.85 (p
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
This study provides an overview of the factors that influence the effect of fermentation on the antioxidant activity and the mechanisms that augment antioxidative activities in fermented plant-based foods. The ability of fermentation to improve antioxidant activity is primarily due to an increase in the amount of phenolic compounds and flavonoids during fermentation, which is the result of a microbial hydrolysis reaction. Moreover, fermentation induces the structural breakdown of plant cell walls, leading to the liberation or synthesis of various antioxidant compounds. These antioxidant compounds can act as free radical terminators, metal chelators, singlet oxygen quenchers, or hydrogen donors to radicals. The production of protease, α-amylase and some other enzymes can be influenced by fermentation that may have metal ion chelation activity. Because the mechanisms that affect antioxidant activity during fermentation are extremely varied, further investigation is needed to establish the precise mechanisms for these processes.
The sum of hydrophilic antioxidants of 23 vegetables and 13 fruits commonly consumed in Japan was evaluated by a modified hydrophilic-oxygen radical absorbance capacity (H-ORAC) method. The “typical vegetable” and “typical fruit” in Japan contained hydrophilic antioxidants that are equivalent to 6.95 and 12.23 μmol of Trolox per g of the edible portion, respectively, on average. Hence, the daily intake of hydrophilic antioxidants from vegetables and fruits was estimated to be 4423 μmol Trolox equivalent (TE)/d based on data of the National Health and Nutrition Survey in Japan. However, the biological significance of these antioxidant values has not yet been clarified. To address this issue, our data will provide a foundation for high-quality epidemiological studies aimed at elucidating the relationship between daily intake of antioxidants and health. In addition, the comparison of the results of the H-ORAC assay with those of polyphenol content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was also studied. The H-ORAC values had a strong positive correlation with polyphenol contents (r = 0.956), and were 1.0–18.2-times higher than the antioxidant capacities evaluated by the DPPH assay.
The aim of the present study was to evaluate the profile of the phenolic constituents of Morus nigra fruits and their antioxidant activity (DPPH) and to compare their contents before and after fermentation. Antioxidant phenolics of black mulberry (M. nigra L.) samples grown in Galicia (NW Spain) were extracted with methanol/formic acid/water (MFW) and determined by high performance liquid chromatography (HPLC). Two major anthocyanins (cyanidin 3-glucoside and cyanidin 3-rutinoside) and two flavonols (quercetin 3-glucoside and rutin) were isolated, together with caffeic acid and other hydroxycinnamic and ellagic acid derivatives. Their chemical structures were identified by spectral analyses with diode array detection (DAD), but also with alkaline saponification and acid hydrolysis of the mulberry phenolics. Good correlations (r2 = 0.6229) were observed among total flavonols contents and the IC50 radical scavenging capacities of mulberry fruits. Anthocyanins are the major flavonoids present in mulberry. It would be expected that anthocyanins contribute significantly to their antioxidant activity; nevertheless, alcohol generated during fermentation may also contribute to antioxidant activity. Our results provide useful antioxidant nutritional information of fresh and fermented mulberry fruits.
Some of the most exciting research in the last decade has been the discovery of a group of nutrients which have protective effects against cell oxidation. These naturally occurring compounds impart bright colour to fruits and vegetables and act as antioxidants in the body by scavenging harmful free radicals, which are implicated in most degenerative diseases. Epidemiological studies have established a positive correlation between the intake of fruits and vegetables and prevention of diseases like atherosclerosis, cancer, diabetes, arthritis and also ageing. So pronounced has been their effect on ageing that they have been called 'fountains of youth'. Fruits and vegetables have thus had conferred on them the status of 'functional foods', capable of promoting good health and preventing or alleviating diseases. Phenolic flavonoids, lycopene, carotenoids and glucosinolates are among the most thoroughly studied antioxidants. The present review highlights the potential of fruits and vegetables rich in antioxidants, their health benefits and the effect of processing on the bioavailability of these nutrients. The paper also reviews some of the important methods used to determine the antioxidant activity.
Evolution of phenolic compounds was studied during spontaneous and controlled fermentations of “Chétoui” cultivar olives at three degree of ripeness. Both spontaneous and controlled fermentations led to an important loss of total phenolic compounds with a reduction rate of 32–58%. Consequently, the antioxidant activity decreased by 50–72%. After fermentations, hydroxytyrosol and caffeic acid concentrations increased, whilst protocatechuic acid, ferulic acid and oleuropein concentrations decreased. The hydroxytyrosol concentration in black olives increased from 165mg/100g dry weight to 312 and 380mg/100g dry weight, respectively, after spontaneous and controlled fermentation. The oleuropein concentration in green olives decreased from 266mg/100g dry weight to 30.7 and 16.1mg/100g dry weight, respectively, after spontaneous and controlled fermentation. During olive fermentation, phenolic loss is essentially due to the diffusion of these compounds into the brine; the main phenolic compound identified and quantified in the different brines was hydroxytyrosol. To preserve antioxidant quality of table olives it is necessary to use a controlled process to minimise phenolic compound loss.