scholarly journals Pekmez ve Erik Kullanılarak Üretilen Kefirlerin Bazı Kalite Kriterlerinin Belirlenmesi

Author(s):  
Tuğba Kök Taş ◽  
Erkut İlay ◽  
Ayla Öker

The aim of this study is to determine the quality characteristics of kefir by developing different flavours in order to increase its consumption. Plum (10%) and molasses (7.5%) which are rich in phenolic contents are used to produce kefir in different flavours. Chemical analysis (pH, titratable acidity, dry matter and colour), microbial analysis (total microorganism, Lactobacillus spp, Lactococcus spp. and yeast counts), total antioxidant activity (by ORAC method), total amount of phenolic contents and sensorial properties of all kefir samples were carried out at the 1st, 7th and 14th days of storage. Consequently, the results of pH, titratable acidity and dry matter in the kefir samples were determined to change between the values 4.11-4.39; 0.22-0.30 and 11.9-17.02% respectively, during the storage. In the colour analysis, the redness colour parameter of the kefir sample produced using molasses was determined to be higher compared to the other kefir samples. At the first day of storage, the total antioxidant contents of the control group kefir, plum- added kefir and molasses-added kefir samples were determined as 13.30; 16.80 and 17.35 µmol ml-1; and the total phenolic contents as 945.70; 2535.8 and 2357.6 mg ml-1, respectively. Content of total microorganism in kefir samples varied between 8.91-9.80 log kob ml-1during the storage period. Lactobacillus spp. and Lactococcus spp. contents of kefir produced using molasses were determined to have the highest values with 9.11 and 9.91 log kob ml-1, respectively, at the first day. Yeast content of the plum kefir and the molasses kefir samples including sugar was detected to be higher than that of the controlled kefir sample. According to the results of the sensory analysis, the kefir produced with plum was approved the most by the panelists. As a result of this study, two alternative products with quite high total phenolic content and antioxidant activity were developed for consumers.

2013 ◽  
Vol 2 (4) ◽  
pp. 107 ◽  
Author(s):  
Antonietta Baiano ◽  
Carmela Terracone

<p>The effects of brewing style on physicochemical indices, iso-a-acids and antioxidant contents of commercial beers were investigated. A great variability was highlighted for all the considered parameters (sugar and alcohol contents, density, pH, titratable acidity, iso-a-acids, phenolic content, antioxidant activity). The beers having the highest iso-a-acids contents were Guinness Special Export Stout (which also showed the highest phenolic content), Chimay Pères Trappistes Triple, and Greene King IPA whereas the lowest values were detected in Cuveè De Ranke, Heineken Premium Quality Lager, and Riedenburger Brauhaus gluten free. The latter also had the lowest phenolic concentration. The antioxidant activity values strictly correlated with the total phenolic content but not with the iso-?-acid amount. The Principal Component Analysis failed in distinguishing beers based on their declared type/styles. This was a predictable result since the beer styles don’t represent a compositional classification but they are rather used to indicate commercial types.</p>


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Muhammad Asam Raza ◽  
Rukhsana Kausar ◽  
Faraz Ali Rana ◽  
Muhammad Danish ◽  
Durre Shahwar ◽  
...  

This study was designed to evaluate the antioxidant potential ofLoranthus pulverulentus. Stem bark, leaves, and seeds ofLoranthus pulverulentuswere extracted in methanol:water (90 : 10) and partitioned with n-hexane, chloroform, ethyl acetate, and n-butanol successively using partition chromatography. Total phenolic contents and antioxidant potential were checked using standard protocols. Total phenolic contents of all extracts were determined, using Folin–Ciocalteu reagent, and ranged between 151 ± 2.1 and 396 ± 1.6 for stem bark, 137 ± 0.9 and 430 ± 2.2 for, and 39 ± 0.6 and 231 ± 1.7 for seeds. The antioxidant potential of extracts was evaluated; namely, DPPH, FRAP, and total antioxidant models. The ethyl acetate extract of stem-bark, leaves, and seeds showed the highest activity in DPPH (94.5 ± 2.1%, 96.30 ± 0.9%, and 92.30 ± 1.1%, IC5015.9 ± 0.5 μg, 14.5 ± 0.8, and 102.7 ± 1.3, resp.), FRAP (7.7 ± 0.6, 7.5 ± 0.7 and 6.6 ± 0.7, resp.), and total antioxidant (0.95 ± 0.09, 1.19 ± 0.09, and 0.686 ± 0.08, resp.). Strong correlations were observed between total phenols versus total antioxidant activity, DPPH, and FRAP withR2values ranging from 0.8185 to 0.9951 (stem-bark), 0.6728 to 0.8648 (leaves), and 0.8658 to 0.9910 (seed) which indicated that phenolic contents are the major constituents responsible for antioxidant activity.


2018 ◽  
Vol 48 (3) ◽  
pp. 386-396 ◽  
Author(s):  
Vania Silva Carvalho ◽  
Ana Carolina Conti-Silva

Purpose This paper aims to examine the bioactive compounds and texture properties of cereal bars formulated with banana peel flour during storage. Design/methodology/approach Seven cereal bars were produced and stored during 11 months, under vacuum and protected from the light. The total phenolic compounds, the activity antioxidant by ABTS [2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] method, the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) method expressed as EC50 (concentration required to reduce the original amount of free radicals by 50 per cent) and texture properties were evaluated over the storage period. Findings In general, total phenolic compounds decreased during storage (from 4.19 to 1.11 mg GAE. g-1f.w.). Although the total antioxidant activity (ABTS method) increased during the fifth month, it reduced during storage (from 3.41 to 0.30 µmol TE.g-1f.w.); and the EC50 was not modified in many formulations, though it decreased in other formulations during storage period (from 3913 to 19221 g fruit.g-1 DPPH). The force of rupture began to increase in the fourth month (reaching 62.4 N), and hardness began to increase in the ninth month (reaching 444 N). The formulation and time factors influenced the total phenolic compounds, total antioxidant activity (ABTS method), force of rupture and hardness, while EC50 was only influenced by the formulation (p-value = 0.001). A principal component analysis showed that time had little effect on the most important characteristics considered in description of the cereal bars. Originality/value Cereal bars can be consumed up to the third month of storage, considering the texture of the products. Moreover, the presence of bioactive compounds in cereal bars depends on the addition of banana peel flour, which it contributes to the insertion of total phenolic compounds and total antioxidant activity in cereal bars, aggregating functional properties in these products.


2020 ◽  
Vol 49 (1) ◽  
pp. 13-22
Author(s):  
P.K. Kannaujia ◽  
N. Patel ◽  
R. Asrey ◽  
M.K. Mahawar ◽  
V.S. Meena ◽  
...  

In this study, six commercial cherry tomato cultivars were analysed for variations in biochemical and technological parameters. Significant differences were observed among cultivars with respect to their technological and functional quality attributes. About 2.48-fold variation in titratable acidity, 2.47-fold variation in total phenolics, 4.13-fold variation in total carotenoid and 7.68-fold variation in lycopene contents were recorded. The total antioxidant activity and respiration rate were also found to vary about 1.85-fold and 1.48-fold, respectively. The highest antioxidant activity and total phenolic content were found in the Cherry tomato hybrid no.1 followed by Pusa cherry tomato-1. Hierarchical cluster analysis revealed that Cherry tomato hybrid no. 1, Pusa cherry tomato-1, and Nagmoti cultivars were abundantly rich in phytochemical and bioactive compounds.


2021 ◽  
Vol 33 (9) ◽  
pp. 2237-2243
Author(s):  
Pooja N. Akhand ◽  
Veena Sharma ◽  
Anupam K. Pathak

In present study, the total phenolic, flavonoid, tannin contents and the antioxidant activity of various solvent extracts of Sphaeranthus indicus collected from three different regions of central India were assessed. Plants extracts were prepared using Soxhlation method, while the total phenols, flavonoids and tannins were measured by the spectrophotometric method. DPPH, metal chelating, nitric oxide, superoxide oxide scavenging activity and FRAP, reducing power, total antioxidant assays were also evaluated. The highest phenolic contents 268.22 GAE equivalent, flavonoids 441.33 QE equivalents and tannin content was 120.32 tannic acid equivalents (mg/g) obtained from ethanolic extracts of sample SIEE-1 compared to other two plants extract. Similarly, the highest flavonoid contents was observed in SIAE-1 aqueous extract and lowest in SIAE-2 and SIAE-3. Extract of SIEE-1 possessed maximum antioxidant potentiality and SIAE-2 shown the least antioxidant activity in all assays. It could be concluded that different agroclimatic conditions have effects on the total phenolics, flavonoids, tannin contents and antioxidant potentiality of S. indicus plant.


2020 ◽  
Vol 17 ◽  
Author(s):  
Le Trung Hieu ◽  
Tran Thi Van Thi ◽  
Le Lam Son ◽  
Nguyen Minh Nhung ◽  
Huynh Thi Ngoc Diep ◽  
...  

Abstract: Helicteres hirsuta, which belongs to the Malvaceae family, is used in traditional medicine to treat malaria, diabetes and cervical cancer. While these uses have not been validated in clinical studies thus far, extracts from H. hirsuta exhibit confirmed antioxidant and potential anti-cancer activity that warrant critical assessment. The aim of this study was to determine the antioxidant properties of different parts of the plant H. hirsuta. The antioxidant capacities of methanol extracts of different plant parts, and specific solvent fractions thereof were determined on the basis of 2,2-diphenyl1picrylhydrazyl (DPPH) radical scavenging and total antioxidant activity assays. The ethyl acetate fraction from leaf material of H. hirsuta has the most potent antioxidant activity with the lowest half maximal inhibitory con-centration (IC50) value of 9.50 μg/mL, that is 4 times lower than the IC50 of curcumin. The amounts of methyl gal-late and rutin dominated the extracts at 8.62 ± 0.01 and 6.76 ± 0.02 mg/g, respectively, out of a total of 21.00 ± 0.01 mg/g active phenolic fraction. The amount of methyl gallate strongly correlated with total phenolic content and total antioxidant capacity, thus this compound may be useful as a marker of antioxidant activity in common medicinal plants


Author(s):  
Hacer Gurkan ◽  
Osman Seracettin Boran ◽  
Ali Adnan Hayaloglu

Four different types of yoghurt were manufactured using purple basil which was added to milk as water extract or powder forms at levels of 1.0 % and 0.4 % (w/w). Physicochemical and rheological properties, antioxidant capacity, color and total phenolic contents of yoghurt samples were measured during 21 days of storage. None of changes were observed for titratable acidity, pH and hardness parameters of yoghurt samples; however, some changes were observed during storage. The contents for total phenolic compounds and antioxidant activity [2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS+*) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH*) values] were dramatically higher in powder-added yoghurt samples than those of its water extract counterparts, while the lowest total phenolics and ABTS+* were observed in control sample during storage. The values for storage and loss modulus were higher in water extract-added samples than powder-added counterparts. In conclusion, no significant effect of the addition of powder or water extract of basil was observed on gross chemical characteristics of yoghurt, while use of basil powder positively contributed to antioxidant activity and changed the rheological behavior of yoghurt gel.


Author(s):  
Mehmet Ali Salık ◽  
Ayla Arslaner ◽  
Songül Çakmakçı

In this study, it was aimed to determine some quality properties of Erzincan mulberry pekmez (molasses) produced with traditional method. For this purpose, various physicochemical properties and antioxidant activity were determined on ten mulberry molasses samples traditionally produced in 2018 and 2019. In the pekmez samples pH 4.86-5.17, titratable acidity 0.53-0.85%, total dry matter 71.91-84.07%, water soluble dry matter 70.60-83.80%, total ash 1.44-3.47%, protein 1.47-3.19%, water activity 0.59-0.75, 5-hydroxymethyl furfural (HMF) 5.70-72.62 mg/kg, total sugar 64.04-71.40%, invert sugar 40.46-56.15%, sucrose 7.76-26.59%, calorie 262.01-294.54 kcal/100 g, viscosity 745-15275 cP, L* value 19.19-32.64, a* value 5.68-17.53, b* value 2.46-9.01, H° value 15.78-52.10 and C* value were detected in the range of 8.74-19.72. Total phenolic content (TFM), 1,1diphenyl-2picyrlhydrazyl (DPPH) antioxidant activity and % inhibition values were found to be in the range of 3.92-10.05 mg GAE/g, 1.31-6.25 mg TE/g and 7.96-30.69%, respectively. According to the results, in general the pekmez samples were found to have quite high nutritional values, to be a good source of antioxidants and TPC, and the amount of HMF remained quite below the limits reported in the TS 12001 Standard (Made From Mulberry). Consequently, it was revealed that molasses which have natural, high nutritional values and health beneficial can be produced with the traditional production technique in Erzincan region. It is thought that these research results will contribute to the importance, promotion, appreciation and protection of Erzincan traditional mulberry pekmez.


2019 ◽  
Vol 17 (1) ◽  
pp. 912-918 ◽  
Author(s):  
Rabia Faki ◽  
Oguz Gursoy ◽  
Yusuf Yilmaz

AbstractElectrospinning is a common technique used for the production of nanofibers, and it is based on the fact that the electrically charged liquid polymer is positioned in a continuous fiber form on a grounded surface. Grape seed is rich in phenolic compounds and can be used as a dietary supplement or as a natural antioxidant source in diet. In this study, grape seed extract of Burdur Dimrit variety (Vitis vinifera L.) was electrospun with gelatin, polyvinyl alcohol (PVA) and PVA/β-cyclodextrin polymers to produce nanofibers with antioxidant activity. The aim of this study was to determine the effect of the electrospinning process on the total antioxidant activity and total phenolic contents of electrospun polymers with grape seed extracts. Total antioxidant activity of samples (by ABTS and DPPH assays) and total phenolic contents (Folin–Ciocalteu method) were determined before and after the electrospinning process of polymers with grape seed extract. Electrospinning with gelatin polymer decreased the antioxidant activity (ABTS assay) of nanofibers containing grape seed extract by 65% and their total phenolic contents by 7%. However, electrospinning treatment with PVA and PVA/β-cyclodextrin had no effect on the total antioxidant activity (ABTS and DPPH) and total phenolic substance contents of grape seed extract nanofibers.


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