Physicochemical properties of Turkish green tea powder: effects of shooting period, shading, and clone

Topuz, Ayhan; Dinçer, Cüneyt; Torun, Mehmet; Tontul, İsmail

doi:10.3906/tar-1307-17

Cited by 36 publications

(30 citation statements)

References 33 publications

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“…Fourteen seasonality studies demonstrated that concentrations of individual catechins, phenolic secondary metabolites, and / or antioxidant activity decreased with a seasonal shift from the spring and/or first tea harvest to other seasons, particularly the monsoon season (Sud and Baru, 2000; Saikia and Mahanta, 2002; Akhlas, 2003; Venkatesan et al, 2007; Chen et al, 2010, 2014; Kottur et al, 2010; Ansari et al, 2011; Jayasekera et al, 2011, 2014; Xu et al, 2012; Ahmed et al, 2014b; Baptista et al, 2014; Topuz et al, 2014). Phenolic catechin compounds are generally associated with high tea quality; however, relatively high concentrations of particular phenolics are linked to a bitter or astringent taste that is generally less desired by consumers (Ahmed et al, 2014b).…”

Section: Resultsmentioning

confidence: 99%

Environmental Factors Variably Impact Tea Secondary Metabolites in the Context of Climate Change

et al. 2019

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Climate change is impacting food and beverage crops around the world with implications for environmental and human well-being. While numerous studies have examined climate change effects on crop yields, relatively few studies have examined effects on crop quality (concentrations of nutrients, minerals, and secondary metabolites). This review article employs a culturally relevant beverage crop, tea ( Camelia sinensis ), as a lens to examine environmental effects linked to climate change on the directionality of crop quality. Our systematic review identified 86 articles as relevant to the review question. Findings provide evidence that shifts in seasonality, water stress, geography, light factors, altitude, herbivory and microbes, temperature, and soil factors that are linked to climate change can result in both increases and decreases up to 50% in secondary metabolites. A gap was found regarding evidence on the direct effects of carbon dioxide on tea quality, highlighting a critical research area for future study. While this systematic review provides evidence that multiple environmental parameters are impacting tea quality, the directionality and magnitude of these impacts is not clear with contradictory evidence between studies likely due to confounding factors including variation in tea variety, cultivar, specific environmental and agricultural management conditions, and differences in research methods. The environmental factors with the most consistent evidence in this systematic review were seasonality and water stress with 14 out of 18 studies (78%) demonstrating a decrease in concentrations of phenolic compounds or their bioactivity with a seasonal shift from the spring and /or first tea harvest to other seasons and seven out of 10 studies (70%) showing an increase in levels of phenolic compounds or their bioactivity with drought stress. Herbivory and soil fertility were two of the variables that showed the greatest contradictory evidence on tea quality. Both herbivory and soil fertility are variables which farmers have the greatest control over, pointing to the importance of agricultural management for climate mitigation and adaptation. The development of evidence-based management strategies and crop breeding programs for resilient cultivars are called for to mitigate climate impacts on crop quality and overall risk in agricultural and food systems.

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Section: Resultsmentioning

confidence: 99%

Environmental Factors Variably Impact Tea Secondary Metabolites in the Context of Climate Change

et al. 2019

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“…The antioxidant activity of the samples was determined by DPPH (2,2‐diphenyl‐1‐picryhydrazyl) radical‐scavenging activity (Topuz et al, ). A series extracts were diluted with methanol.…”

Section: Methodsmentioning

confidence: 99%

Sugar, d ‐pinitol, volatile composition, and antioxidant activity of carob powder roasted by microwave, hot air, and combined microwave/hot air

Günel

Torun

Sahin‐Nadeem

2019

J Food Process Preserv

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The effects of hot air, microwave, and combined microwave/hot air roasting on physical and chemical properties of carob powder were determined. The comparison of different roasting processes was evaluated whether the combined microwave/hot air roasting could be an alternative to other roasting methods or not. The moisture content (2.86%–5.03%), water activity (0.20–0.35), and pH (4.94–5.12) values of the carob powder decreased by increasing microwave power and roasting time; whereas total phenolic content (10.13–13.74 mg/g dm), total antioxidant activity (0.69–1.53 g/mg DPPH), browning index (23.57–70.30), and UV absorbance (427.41–701.05) increased. Hunter L (41.54–55.28) and b (16.45–20.91) values of the carob powder decreased after roasting while color value a (8.88–20.91) increased. The main sugar was sucrose (317.54–347.68 mg/kg), followed by fructose (80.98–90.11 mg/kg), and glucose (45.16–62.19 mg/kg). Roasting process reduced the sugar content while increased the d‐pinitol (62.41–76.71 mg/kg) content. The main volatile was isobutyric acid (acidic/butter odor). Hot air and the combined microwave/hot air roasted samples showed similar volatile and sensorial profile. According to the results, the combined microwave/hot air roasting consumed 50% less energy than the hot air roasting and got the best sensory scores. Practical applications The effects of microwave, hot air, and the combined microwave/hot air roasting processes on the properties of carob powder were first investigated. d‐pinitol content of carob was increased by roasting processes. Different roasting processes increased organoleptic properties of carob powder. Total phenolic content and antioxidant activity of carob powder increased by roasting. The combined microwave/hot air roasting consumed 50% less energy than the hot air roasting and it is recommended to produce carob powder with preferable product quality.

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“…Pembuatan teh herbal daun alpukat dimulai dari persiapan bahan berupa pencucian dan penirisan daun alpukat, pelayuan dengan pengukusan pada suhu 80, 90, dan 100°C selama 1, 3, dan 5 menit (sesuai perlakuan), pendinginan, pengeringan pada suhu 90°C selama 25 menit, penghilangan batang dan tulang daun, serta penggilingan (Topuz et al, 2014). Selanjutnya teh herbal daun alpukat kering dihaluskan dengan menggunakan blender kemudian diayak dengan ayakan 40 mesh.…”

Section: Persiapan Sampelunclassified

Kajian Waktu dan Suhu Pelayuan Daun Alpukat dalam Upaya Pemanfaatanya sebagai Teh Herbal

Widarta

Wiadnyani

Permana

2018

JATP

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Artikel ini dikirim pada tanggal 01 Januari 2018 dan dinyatakan diterima tanggal 24 Mei 2018. Artikel ini juga dipublikasi secara online melalui www.https://ejournal2.undip.ac.id/index.php/jatp. Hak cipta dilindungi undang-undang. Dilarang diperbanyak untuk tujuan komersial. Diproduksi oleh Indonesian Food Technologists® ©2018 Abstrak Daun Alpukat mengandung komponen bioaktif yang tinggi sehingga dapat dimanfaatkan sebagai pangan fungsional seperti teh herbal. Tujuan dari penelitian ini adalah mendapatkan suhu dan waktu pelayuan daun alpukat yang tepat sehingga menghasilkan teh herbal dengan karakteristik sensoris terbaik serta komponen bioaktif dan aktivitas antioksidan yang tinggi. Pelayuan dilakukan dengan cara pengukusan pada suhu 80, 90, dan 100°C selama 1, 3 dan 5 menit. Karakteristik teh yang diamati meliputi kadar total tanin, kadar total fenol, total flavonoid dan aktivitas antioksidan serta evaluasi sensorisnya. Hasil penelitian menunjukkan bahwa suhu dan waktu pelayuan yang terbaik diperoleh pada suhu 90°C selama 5 menit dengan karakteristik teh herbal daun alpukat yang dihasilkan yaitu total fenolik 296,48 mg/g ekstrak, total flavonoid 644 mg/g ekstrak, total tanin 315,14 mg/g ekstrak, warna seduhan teh coklat kekuningan, rasa agak tidak pahit dan aroma agak khas daun alpukat serta dengan penerimaan keseluruhan agak suka. Sementara itu, nilai IC50 baik yang diukur dengan metode DPPH maupun reducing power masing-masing adalah 527,93 mg/L dan 78,95 mg/L. Kesimpulannya, suhu dan waktu pelayuan daun alpukat berpengaruh terhadap komponen bioaktif dan aktivitas antioksidan yang terkandung pada teh herbal yang dihasilkan. Kata kunci: antioksidan, daun alpukat, teh herbal, karakteristik sensoris

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Physicochemical properties of Turkish green tea powder: effects of shooting period, shading, and clone

Cited by 36 publications

References 33 publications

Environmental Factors Variably Impact Tea Secondary Metabolites in the Context of Climate Change

Environmental Factors Variably Impact Tea Secondary Metabolites in the Context of Climate Change

Sugar, d ‐pinitol, volatile composition, and antioxidant activity of carob powder roasted by microwave, hot air, and combined microwave/hot air

Kajian Waktu dan Suhu Pelayuan Daun Alpukat dalam Upaya Pemanfaatanya sebagai Teh Herbal

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