Change of enzyme activity and quality during the processing of Turkish green tea

Öztürk, Bengü; Seyhan, Ferda; Özdemir, İbrahim Sani; Karadeniz, Bülent; Bahar, Banu; Ertaş, Erdal; Ilgaz, Saziye

doi:10.1016/j.lwt.2015.07.068

Cited by 31 publications

(15 citation statements)

References 18 publications

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“…The thermostability of tannase from A. niger is mainly between 30 • C and 50 • C [14][15][16]. Many studies have focused on the application of tannase in tea extract at 30-50 • C to reduce tea cream formation and improve the taste and color of green tea beverages [10,17,18]. The application of a thermally stable tannase derived from a food-grade microorganism in the enzymatic extraction of tea at high temperatures (≥ 70 • C) has not been studied yet.…”

Section: Introductionmentioning

confidence: 99%

Thermostable Tannase from Aspergillus Niger and Its Application in the Enzymatic Extraction of Green Tea

Yuan

Zhang

et al. 2020

Molecules

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Tannase is widely used in tea beverage processing because of its ability to catalyze the hydrolysis of hydrolysable tannins or gallic acid esters and effectively improve the quality of tea extracts through enzymatic extraction. A new thermophilic tannase was cloned from Aspergillus niger FJ0118 and characterized. The tannase exhibited an optimal reaction temperature of 80 °C and retained 89.6% of the initial activity after incubation at 60 °C for 2 h. The enzymatic extraction of green tea at high temperature (70 °C) for a short time (40 min) was devised on the basis of the superior thermal stability of tannase. The enzymatic reaction significantly increased the total polyphenol content of green tea extract from 137 g·kg−1 to 291 g·kg−1. The enzymatic reaction effectively degraded the ester catechins into non-ester catechins compared with the water extraction method. Results suggested that the thermally stable tannase exhibited potential applications in the enzymatic extraction of green tea beverage.

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Section: Introductionmentioning

confidence: 99%

Thermostable Tannase from Aspergillus Niger and Its Application in the Enzymatic Extraction of Green Tea

Yuan

Zhang

et al. 2020

Molecules

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“…Fernandez et al As EGCG is the major tea catechin, its content in different type of tea samples were also studied. of Turkish green tea and found EGCG content between 6.10-6.74 g/100g [27].…”

Section: Resultsmentioning

confidence: 97%

“…On the other hand, Zuo et al [20] analyzed total eight tea samples, four of tea samples were green tea and EGCG content was determined the in the range of 51.1-62.4 mg/g in green tea samples, in that study black tea sample was found to contain 3.79 mg/100ml EGCG. Ozturk et al studied on quality parameters of Turkish green tea and found EGCG content between 6.10-6.74 g/100g [27].…”

Section: Fernandez Et Almentioning

confidence: 99%

Evaluation on Gallic Acid, EGCG Contents and Antiradical Activity of Green Tea and Black Tea Extracts

Ağca

Batçıoğlu

Şarer

2020

Ankara Universitesi Eczacilik Fakultesi Dergisi

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Objective: Tea is very well known and consumed beverage worldwide also cultivated widely. It is one of phytonutrients that has a protective role associated with its antioxidant activity. The aim of this article is to study the gallic acid, epigallocatechin gallate contents and antiradical activity of green tea and black tea extracts from Camellia sinensis cultivated in North Anatolia. Material and Method: Gallic acid and epigallocatechin gallate contents were investigated in ethanol, methanol and water extracts of green tea and black tea by HPLC analysis and the antiradical activities were also examined for scavenging effect on DPPH and ABTS free radicals. Result and Discussion: In total 6 extracts, gallic acid contents were determined in the range of 0.052-1.341 mg/100 ml and the value of EGCG (epigallocatechin gallate) were found between 0-19.54 mg/100ml. Water extract of green tea exhibited the best antiradical activity on both DPPH and ABTS radicals. Green tea could be evaluated as a good candidate for health prevention but it should be noted that the harvesting method and manufacturing process, optimum conditions on brewing time, the solvent used, chopping grade of tea leaves should also be taken into consideration during formulating both phytonutrient and pharmaceutical grade products.

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“…Terdapat 2 tipe pengolahan teh hijau pada proses inaktivasi enzim polifenol oksidase/pelayuan (Handayani, 2014). Tipe pengolahan teh hijau versi Jepang menggunakan uap panas dalam proses pelayuannya sedangkan pada versi Cina menggunakan metode inaktivasi melalui kontak daun teh dengan permukaan panas (umumnya berbentuk silinder yang berputar) (Ozturk et al, 2016). Teh hijau diproduksi di beberapa wilayah perkebunan teh yang berasal dari satu atau beberapa wilayah produksi.…”

Section: Jenis Pengolahan Tehunclassified

Evaluasi Kesesuaian Mutu Produk Teh Dengan Persyaratan Standar Nasional Indonesia

et al. 2021

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Indonesia merupakan produsen teh terbesar ke tujuh dunia dengan total produk mencapai 125 ribu ton pada 2016 yang berkontribusi sebesar 3% dari total produksi teh dunia. Kualitas produk teh merupakan faktor utama untuk meningkatkan daya saing produk teh Indonesia. Penelitian ini bertujuan untuk mengevaluasi kesesuaian mutu produk teh dengan persyaratan SNI. Parameter mutu yang dievaluasi meliputi kadar air, kadar abu total, kadar abu larut dalam air, kadar abu larut asam, dan kadar alkalinitas abu. Sebanyak 18 produk teh yang terdiri atas teh hitam, teh putih, teh hijau, teh hijau melati, dan bubuk teh hijau digunakan dalam penelitian. Hasil penelitian menunjukkan bahwa Kadar air dari 18 sampel produk teh berkisar antara 1,6% hingga 14%. Sebanyak 9 (sembilan) sampel produk teh memiliki kadar air yang melebihi standar yang disyaratkan oleh SNI. Produk teh hijau dan teh hijau melati memiliki kadar abu larut dalam air sebesar 33,25% dan 41,15% lebih rendah jika dibandingkan dengan persyaratan yang ditetapkan oleh SNI sebesar minimal 45%. Secara keseluruhan, produk teh telah memenuhi persyaratan SNI teh pada parameter kadar abu total, kadar abu tidak larut asam, dan alkalinitas abu. Beberapa parameter seperti kadar abu larut dalam air, abu tidak larut dalam asam, dan alkalinitas abu belum ditetapkan standarnya pada SNI 7707-2011 tentang teh instan dan SNI 01-1898-2002 tentang teh wangi. Penelitian lebih lanjut diperlukan untuk mengevaluasi mutu produk teh dari aspek kimia, cemaran logam mineral, dan mikrobiologi yang ditetapkan di SNI.

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Change of enzyme activity and quality during the processing of Turkish green tea

Cited by 31 publications

References 18 publications

Thermostable Tannase from Aspergillus Niger and Its Application in the Enzymatic Extraction of Green Tea

Thermostable Tannase from Aspergillus Niger and Its Application in the Enzymatic Extraction of Green Tea

Evaluation on Gallic Acid, EGCG Contents and Antiradical Activity of Green Tea and Black Tea Extracts

Evaluasi Kesesuaian Mutu Produk Teh Dengan Persyaratan Standar Nasional Indonesia

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