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1
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Yan C, Fyfe C, Minty L, Barrington H, Jamieson C, Reid M. Computer vision as a new paradigm for monitoring of solution and solid phase peptide synthesis. Chem Sci 2023; 14:11872-11880. [PMID: 37920332 PMCID: PMC10619640 DOI: 10.1039/d3sc01383a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 10/04/2023] [Indexed: 11/04/2023] Open
Abstract
We report a strategy for the camera-enabled non-contact colourimetric reaction monitoring and optimisation of amide bond formation, mediated by coupling reagents. For amide bond formation in solution phase, investigation of reactions mediated by HATU, PyAOP, and DIC/Oxyma evidenced correlations between colour parameters extracted from video data and conversion to amide product measured by off-line HPLC analysis of concentration. These correlations, supported by mutual information analysis, were further investigated using video recordings of solid phase peptide synthesis (SPPS), co-analysed by off-line HPLC to track remaining unreacted substrate in solution. An optimisation method of coupling time in SPPS was derived from ΔE (a measurement of colour contrast), giving comparable isolated peptide yield and purity at 65-95% reduced overall reaction time. The same colour data enabled data-rich monitoring of reaction rate attenuation, consisted with computationally-derived measures of amino acid steric bulk. These findings provide a foundation for exploring the use of camera technology and computer vision towards automated and online mechanistic profiling of SPPS.
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Affiliation(s)
- Chunhui Yan
- WestCHEM Department of Pure & Applied Chemistry, University of Strathclyde Glasgow UK
| | - Calum Fyfe
- WestCHEM Department of Pure & Applied Chemistry, University of Strathclyde Glasgow UK
| | - Laura Minty
- WestCHEM Department of Pure & Applied Chemistry, University of Strathclyde Glasgow UK
| | - Henry Barrington
- WestCHEM Department of Pure & Applied Chemistry, University of Strathclyde Glasgow UK
| | - Craig Jamieson
- WestCHEM Department of Pure & Applied Chemistry, University of Strathclyde Glasgow UK
| | - Marc Reid
- WestCHEM Department of Pure & Applied Chemistry, University of Strathclyde Glasgow UK
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2
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Song F, Zheng Y, Li R, Li Z, Liu B, Wu X. Intelligent control of green tea fixation with Microwave Processing. J FOOD ENG 2023. [DOI: 10.1016/j.jfoodeng.2023.111481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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3
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Yan C, Cowie M, Howcutt C, Wheelhouse KMP, Hodnett NS, Kollie M, Gildea M, Goodfellow MH, Reid M. Computer vision for non-contact monitoring of catalyst degradation and product formation kinetics. Chem Sci 2023; 14:5323-5331. [PMID: 37234891 PMCID: PMC10208035 DOI: 10.1039/d2sc05702f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/27/2023] [Indexed: 08/24/2023] Open
Abstract
We report a computer vision strategy for the extraction and colorimetric analysis of catalyst degradation and product-formation kinetics from video footage. The degradation of palladium(ii) pre-catalyst systems to form 'Pd black' is investigated as a widely relevant case study for catalysis and materials chemistries. Beyond the study of catalysts in isolation, investigation of Pd-catalyzed Miyaura borylation reactions revealed informative correlations between colour parameters (most notably ΔE, a colour-agnostic measure of contrast change) and the concentration of product measured by off-line analysis (NMR and LC-MS). The breakdown of such correlations helped inform conditions under which reaction vessels were compromised by air ingress. These findings present opportunities to expand the toolbox of non-invasive analytical techniques, operationally cheaper and simpler to implement than common spectroscopic methods. The approach introduces the capability of analyzing the macroscopic 'bulk' for the study of reaction kinetics in complex mixtures, in complement to the more common study of microscopic and molecular specifics.
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Affiliation(s)
- Chunhui Yan
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
| | - Megan Cowie
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
| | - Calum Howcutt
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
| | | | | | - Martin Kollie
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
| | - Martin Gildea
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
| | - Martin H Goodfellow
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
| | - Marc Reid
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow UK
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4
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Ye F, Qiao X, Gui A, Liu P, Wang S, Wang X, Teng J, Zheng L, Feng L, Han H, Zhang B, Chen X, Gao Z, Gao S, Zheng P. Characterization of Roasting Time on Sensory Quality, Color, Taste, and Nonvolatile Compounds of Yuan An Yellow Tea. Molecules 2022; 27:molecules27134119. [PMID: 35807365 PMCID: PMC9268202 DOI: 10.3390/molecules27134119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/23/2022] [Accepted: 06/23/2022] [Indexed: 01/27/2023] Open
Abstract
Roasting is crucial for producing Yuan An yellow tea (YAYT) as it substantially affects sensory quality. However, the effect of roasting time on YAYT flavor quality is not clear. To investigate the effect of roasting time on the sensory qualities, chemical components, odor profiles, and metabolic profile of YAYTs produced with 13 min roasting, 16 min roasting, 19 min roasting, 22 min roasting, and 25 min roasting were determined. The YAYTs roasted for 22 min got higher sensory scores and better chemical qualities, such as the content of gallocatechin (GC), gallocatechin gallate (GCG), free amino acids, solutable sugar, meanwhile the lightness decreased, the hue of tea brew color (b) increased, which meant the tea brew got darker and yellower. YAYTs roasted for 22 min also increased the contents of key odorants, such as benzaldehyde, nonanal, β-cyclocitral, linalool, nerol, α-cedrol, β-ionone, limonene, 2-methylfuran, indole, and longiborneol. Moreover, non-targeted metabolomics identified up to 14 differentially expressed metabolites through pair-wise comparisons, such as flavonoids, phenolic acids, sucrose, and critical metabolites, which were the main components corresponding to YAYT roasted for 22 min. In summary, the current results provide scientific guidance for the production of high quality YAYT.
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Affiliation(s)
- Fei Ye
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
- Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Tea Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, China;
| | - Xiaoyan Qiao
- Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Tea Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, China;
| | - Anhui Gui
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Panpan Liu
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Shengpeng Wang
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Xueping Wang
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Jin Teng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Lin Zheng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Lin Feng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Hanshan Han
- MuLanTia Xiang Co., Ltd., Huangpi District, Wuhan 432200, China;
| | - Binghua Zhang
- Danding Tea Company Limited, Danjiangkou Conty, Shiyan 442717, China;
| | - Xun Chen
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
| | - Zhiming Gao
- Yuan’an Lei Zu Tea Company Limited, Yuan’an Conty, Yichang 444205, China;
| | - Shiwei Gao
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
- Correspondence: (S.G.); (P.Z.)
| | - Pengcheng Zheng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430068, China; (F.Y.); (A.G.); (P.L.); (S.W.); (X.W.); (J.T.); (L.Z.); (L.F.); (X.C.)
- Correspondence: (S.G.); (P.Z.)
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Ye F, Qiao X, Gui A, Wang S, Liu P, Wang X, Teng J, Zheng L, Feng L, Han H, Gao S, Zheng P. Metabolomics Provides A Novel Interpretation of the Changes in Main Compounds during Black Tea Processing through Different Drying Methods. Molecules 2021; 26:molecules26216739. [PMID: 34771147 PMCID: PMC8587435 DOI: 10.3390/molecules26216739] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 01/18/2023] Open
Abstract
This study aimed to compare the effect of hot roller (HR) drying and hot air (HA) drying on the sensory evaluation, chemical quality, antioxidant activity, and metabolic profile of Yihong Congou black tea processed from E’cha NO1. The Yihong Congou black tea dried with HA obtained higher sensory scores and better chemical qualities such as the hue of tea brew color (a and b), content of theaflavins, thearubigins, water extract, free amino acids, tea polyphenol, and the ratio of polyphenol to amino acids as well as higher antioxidant capacities compared to that dried with HR. The HA drying tea increased the contents of volatile compounds that had positive correlation with sweet and flowery flavor, while the HR drying tea increased the contents of volatile compounds related to fruity flavor. Moreover, non-targeted metabolomics data indicated that the levels of most free amino acids significantly increased, while the levels of most soluble sugars reduced in the HA drying method compared to the HR drying method. The metabolic analysis was also consistent with the above results and revealed that D-ribose and gallic acid were the main characteristic metabolites of HA drying. Our results could provide a technical reference and theoretical guide to processing a high quality of Yihong Congou black tea.
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Affiliation(s)
- Fei Ye
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
- Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Tea Research Institute, Guangdong Academy of Agricultural Sciences, No.6 Dafeng Avenue, Tianhe District, Guangzhou 510665, China;
| | - Xiaoyan Qiao
- Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Tea Research Institute, Guangdong Academy of Agricultural Sciences, No.6 Dafeng Avenue, Tianhe District, Guangzhou 510665, China;
| | - Anhui Gui
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Shengpeng Wang
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Panpan Liu
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Xueping Wang
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Jin Teng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Lin Zheng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Lin Feng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
| | - Hanshan Han
- Mu Lan Tian Xiang Co., Ltd., Huangpi District, Wuhan 432200, China;
| | - Shiwei Gao
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
- Correspondence: (S.G.); (P.Z.)
| | - Pengcheng Zheng
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, No.10 South Lake Avenue, Hongshan District, Wuhan 430064, China; (F.Y.); (A.G.); (S.W.); (P.L.); (X.W.); (J.T.); (L.Z.); (L.F.)
- Correspondence: (S.G.); (P.Z.)
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Zou Y, Ma W, Tang Q, Xu W, Tan L, Han D, Tian Y, Yuan Y. A high‐precision method evaluating color quality of Sichuan Dark Tea based on colorimeter combined with multi‐layer perceptron. J FOOD PROCESS ENG 2020. [DOI: 10.1111/jfpe.13444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yao Zou
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Wanjun Ma
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Qian Tang
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Wei Xu
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Liqiang Tan
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Deyang Han
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Yun Tian
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
| | - Yue Yuan
- Department of Tea ScienceCollege of Horticulture, Sichuan Agricultural University Chengdu China
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Process kinetics on physico-chemical and peroxidase activity for different blanching methods of sweet corn. Journal of Food Science and Technology 2018; 55:4823-4832. [PMID: 30482977 DOI: 10.1007/s13197-018-3416-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 09/03/2018] [Accepted: 09/05/2018] [Indexed: 10/28/2022]
Abstract
Blanching was performed to inactivate the enzyme using microwave, steam and hot water blanching methods and effect on the enzymatic activity, chemical properties and physical properties of the sweet corn were studied. The effectiveness of each blanching process was evaluated by measuring the loss of peroxidase activity, which was lost after 60, 90 and 120 s with k-values 0.016, 0.024 and 0.028 s-1 following first order kinetics for microwave, steam and hot water blanching respectively. The total sugar, ascorbic acid, moisture content, kernel mass and geometric diameter changed from 8.40 to 6.30, 7.20 and 7.50 g/100 g; 7.15 to 5.70, 6.10 and 6.60 mg/100 g; 76 to 79.20, 78.20 and 75.30%; 0.47 to 0.53, 0.50 and 0.42 g; 8.00 to 8.50, 8.30 and 7.20 mm at optimum level of blanching during microwave, steam and hot water blanching respectively, indicating higher retention of total sugar and ascorbic acid in microwave blanching. The change in colour, especially increase in brownness was observed during blanching processes. The average R2 for zero-order model was 0.945, suggesting use of model for prediction of physico-chemical parameters during blanching process of sweet corn.
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Sun Q, Zhang M, Mujumdar AS. Recent developments of artificial intelligence in drying of fresh food: A review. Crit Rev Food Sci Nutr 2018; 59:2258-2275. [PMID: 29493285 DOI: 10.1080/10408398.2018.1446900] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Intellectualization is an important direction of drying development and artificial intelligence (AI) technologies have been widely used to solve problems of nonlinear function approximation, pattern detection, data interpretation, optimization, simulation, diagnosis, control, data sorting, clustering, and noise reduction in different food drying technologies due to the advantages of self-learning ability, adaptive ability, strong fault tolerance and high degree robustness to map the nonlinear structures of arbitrarily complex and dynamic phenomena. This article presents a comprehensive review on intelligent drying technologies and their applications. The paper starts with the introduction of basic theoretical knowledge of ANN, fuzzy logic and expert system. Then, we summarize the AI application of modeling, predicting, and optimization of heat and mass transfer, thermodynamic performance parameters, and quality indicators as well as physiochemical properties of dried products in artificial biomimetic technology (electronic nose, computer vision) and different conventional drying technologies. Furthermore, opportunities and limitations of AI technique in drying are also outlined to provide more ideas for researchers in this area.
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Affiliation(s)
- Qing Sun
- a State Key Laboratory of Food Science and Technology, Jiangnan University , Jiangsu , China.,c International Joint Laboratory on Food Safety, Jiangnan University , Jiangsu , China
| | - Min Zhang
- a State Key Laboratory of Food Science and Technology, Jiangnan University , Jiangsu , China.,b Jiangsu Province Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University , Wuxi , China
| | - Arun S Mujumdar
- d Department of Bioresource Engineering, Macdonald Campus, McGill University, Ste. Anne de Bellevue , Quebec , Canada
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Regression Models for Description of Roasted Ground Coffee Powder Color Change during Secondary Shelf-Life as Related to Storage Conditions and Packaging Material. BEVERAGES 2018. [DOI: 10.3390/beverages4010016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Artificial Neural Network Modeling of Drying Kinetics and Color Changes of Ginkgo Biloba Seeds during Microwave Drying Process. J FOOD QUALITY 2018. [DOI: 10.1155/2018/3278595] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Ginkgo biloba seeds were dried in microwave drier under different microwave powers (200, 280, 460, and 640 W) to determinate the drying kinetics and color changes during drying process. Drying curves of all samples showed a long constant rate period and falling rate period along with a short heating period. The effective moisture diffusivities were found to be 3.318 × 10−9 to 1.073 × 10−8 m2/s within the range of microwave output levels and activation energy was 4.111 W/g. The L⁎ and b⁎ values of seeds decreased with drying time. However, a⁎ value decreased firstly and then increased with the increase of drying time. Artificial neural network (ANN) modeling was employed to predict the moisture ratio and color parameters (L⁎, a⁎, and b⁎). The ANN model was trained for finite iteration calculation with Levenberg-Marquardt algorithm as the training function and tansig-purelin as the network transfer function. Results showed that the ANN methodology could precisely predict experimental data with high correlation coefficient (0.9056–0.9834) and low mean square error (0.0014–2.2044). In addition, the established ANN models can be used for online prediction of moisture content and color changes of ginkgo biloba seeds during microwave drying process.
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Roshanak S, Rahimmalek M, Goli SAH. Evaluation of seven different drying treatments in respect to total flavonoid, phenolic, vitamin C content, chlorophyll, antioxidant activity and color of green tea (Camellia sinensis or C. assamica) leaves. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2016; 53:721-9. [PMID: 26787992 PMCID: PMC4711456 DOI: 10.1007/s13197-015-2030-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 08/28/2015] [Accepted: 09/08/2015] [Indexed: 10/23/2022]
Abstract
The effect of seven drying treatments (sun, shade, oven 60 °C, oven 80 °C, oven 100 °C, microwave and freeze-drying) were evaluated with respect total flavonoid (TFC), phenolic (TPC), antioxidant activity, vitamin C and color characteristics of green tea. In general, drying increased antioxidant activity, TPC, TFC and chlorophyll content, while it led to a decrease in vitamin C. The highest TPC (209.17 mg Gallic acid/gdw) and TFC (38.18 mg Quercitin/gdw) were obtained in oven drying at 60 and 100 °C, respectively. Among methods, oven drying at 60 °C revealed the highest radical scavenging activity (IC50 = 167.166 μg/ml), while microwave showed the lowest one (IC50 = 505.5 μg/ml). Similar trend was also observed in reducing power assay. The highest vitamin C (16.36 mg/100gDM) and Chlorophyll a (17.35 mg/l) were obtained in freeze drying. Finally, sun and freeze drying methods were considered as the least and the most desirable drying methods, respectively the final color of green tea leaves.
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Affiliation(s)
- Sahar Roshanak
- />Department of Food Science, College of Agriculture, Isfahan University of Technology, Isfahan, 84156 83111 Iran
| | - Mehdi Rahimmalek
- />Department of Agronomy and Plant breeding, College of Agriculture, Isfahan University of Technology, Isfahan, 84156 83111 Iran
| | - Sayed Amir Hossein Goli
- />Department of Food Science, College of Agriculture, Isfahan University of Technology, Isfahan, 84156 83111 Iran
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