scholarly journals Effects of Organic Fertilizer and Drying Methods on Total Phenolic Content and Antioxidant Capacity of Organic White Tea (Camellia sinensis (L.) Kuntze)

Author(s):  
Emine Yurteri ◽  
Aysel Özcan ◽  
Fatih Seyis

The aim of this study was to determine the effect of different fertilizer doses and drying methods on total phenolic contents and antioxidant activity of organic white tea (Camellia sinensis (L.) Kuntze) obtained from Hemşin Valley, region of Rize/Turkey. The determination of phenolic constituents was done by the Folin-Ciocalteau method and the determination of antioxidant activity by the FRAP method. The results showed that the phenolic content of white tea was as follows: 443,7- 506,2 µg GAE/g DW in the drying oven, 421,4- 473,6 µg GAE/g DW in shadow and 434,4- 485,2 µg GAE/g DW in the liofilizator. According to the FRAP method the antioxidant activity was as follows: 1130,1-1176,9 mg FeSO4/gr DW in drying oven, 1141,2-1157,1 mg FeSO4/gr DW in shadow and 1005,3-1183,2 mg FeSO4/gr DW in lyophylizator. The results revealed that different fertilizer doses and drying methods had important effects on the total phenolic content and antioxidant activity of white tea.

2014 ◽  
Vol 4 (2) ◽  
pp. 68 ◽  
Author(s):  
Umesh C. Lohani ◽  
Kasiviswanathan Muthukumarappan

Although extrusion is a promising process to develop ready to eat cereals and snacks, thermal treatment to raw material during extrusion results in degradation of phenolic compounds. Therefore, an approach was made to enhance the total phenolic content (TPC) and antioxidant activity (AA) of apple pomace (AP) prior to extrusion process. In this study, AP powder was naturally fermented (F) for 12 h and then was subjected to ultrasonication (U) at various conditions [25, 37, and 50 µm ultrasonication amplitude (UA) for 1, 2, and 3 min of ultrasonication time (UT)]. AP was then dried in oven (O) and microwave (MW), separately and thus four drying methods, i.e. O<sub>F</sub>-O<sub>U</sub>, O<sub>F</sub>-MW<sub>U</sub>, MW<sub>F</sub>-O<sub>U</sub>, MW<sub>F</sub>-MW<sub>U</sub> were used in combinations. Full factorial design was used for experimental plan and results were analyzed using statistical software. It was observed that drying method significantly affected the TPC and AA of AP powder followed by UA. UT did not have any significant effect on TPC, and AA. Maximum TPC, and AA observed for the AP powder dried in MW after fermentation and ultrasonication (MW<sub>F</sub>-MW<sub>U</sub>) at 50 µm UA for 3 min UT were 372.98 mg GAE/100g DW, and 729.67 µmol TE/100 g DW, respectively. MW<sub>F</sub>-MW<sub>U</sub> drying exhibited a more prominent disrupted and porous structure of AP powder compared with that of O<sub>F</sub>-O<sub>U</sub> drying.


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.


2012 ◽  
Vol 60 (18) ◽  
pp. 4709-4717 ◽  
Author(s):  
G. Astrid Garzón ◽  
Carlos-Eduardo Narváez-Cuenca ◽  
Rachel E. Kopec ◽  
Andrew M. Barry ◽  
Kenneth M. Riedl ◽  
...  

2021 ◽  
Vol 13 (2) ◽  
pp. 137-142
Author(s):  
Kasta Gurning ◽  
◽  
Sifikal Lumbangaol ◽  
Risanti F. R. Situmorang ◽  
Saronom Silaban ◽  
...  

The research objectives were to identify the secondary metabolite components, total phenolic content and determine the antioxidant activity of the ethanol extract of red betel leaf (Piper crocatum Ruiz & Pav.). The extraction process was carried out by materation using ethanol as a solvent. Determination of total phenolic content was carried out colorimetrically with Folin-Ciocalteu reagent measured at a maximum wavelength of 765 nm. Determination of antioxidant activity using the DPPH method measured by spectrophotometry at a maximum wavelength of 517 nm. The results of phytochemical screening of the ethanolic extract of red betel leaf contain secondary metabolites, including flavonoid, phenolic, tannin, alkaloids, steroids, and triterpenoids. The total phenolic content of the red betel leaf ethanol extract was 0.949±0.003 mg GAE/g d.w. and has antioxidant activity (IC50) 84,656 including strong category as an antioxidant. Keywords: Piper crocatum Ruiz & Pav., Antioxidant, Ethanol extract, Folin-Ciocalteu and DPPH


Talanta ◽  
2019 ◽  
Vol 198 ◽  
pp. 542-549 ◽  
Author(s):  
Chanoknan Puangbanlang ◽  
Kitima Sirivibulkovit ◽  
Duangjai Nacapricha ◽  
Yupaporn Sameenoi

Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 194 ◽  
Author(s):  
Ioannis Karabagias ◽  
Miguel Maia ◽  
Vassilios Karabagias ◽  
Ilias Gatzias ◽  
Anastasia Badeka

The present study was conducted to evaluate the quality and bio-functional properties of Portuguese honeys of different botanical and geographical origins. Quality parameter analyses included the determination of palynological (predominant, secondary, minor and isolated pollen percentage), physicochemical (°Brix, moisture content, pH, electrical conductivity, free acidity, total dissolved solids, salinity, vitamin C content and specific weight) including colour-metrics (CIELAB, Pfund and colour intensity determinations), along with volatile compounds identification using solid phase micro-extraction coupled to gas chromatography mass spectrometry. Bio-activity parameter analysis included the determination of in vitro antioxidant activity and total phenolic content using the 2,2-diphenyl-1-picryl-hydrazyl and Folin-Ciocalteu assays, respectively. Melissopalynological analysis showed that Portuguese honeys were classified as eucalyptus, chestnut and heather, recording significant variations (p < 0.05) among physicochemical, volatile and bio-activity parameter analyses according to both: botanical and geographical origin. Based on the multi-parameter analysis data Portuguese honeys could be characterized by a distinctive colour, a characteristic aroma, whereas conform to the European legislation relating to honey identity and quality. Specific attention should be given in the case of heather honey which showed the highest in vitro antioxidant activity and total phenolic content. Parameters that were also highly correlated using bivariate statistics.


Lab on a Chip ◽  
2016 ◽  
Vol 16 (17) ◽  
pp. 3268-3275 ◽  
Author(s):  
Apichai Phonchai ◽  
Yubin Kim ◽  
Rattikan Chantiwas ◽  
Yoon-Kyoung Cho

This paper reports the simultaneous determination of TPC and AA of beverages using lab-on-a-disc.


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