Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Adaptations that Reduce Water Loss01:57

Adaptations that Reduce Water Loss

Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Dietary gamma-oryzanol and vitamin E tocotrienols mitigate the negative impacts in laying hens reared under high stocking density.

Journal of animal science and technology·2026
Same author

Physicochemical Properties, Fatty Acid Composition, and Nutritional Quality of Thai Perilla Seed Oil, Sesame Seed Oil, and Their Blended Oil.

Journal of oleo science·2026
Same author

Effect of Microencapsulated Medium-Chain Fatty Acids, Lignocellulose, and Heat-Killed <i>Lactobacillus plantarum</i> L-137 Supplementation on Lactating Sow Performance, and Nutritional and Immunological Parameters in Colostrum.

Veterinary sciences·2025
Same author

Impact of pH-Shifting and Autoclaving on the Allergenic Potential of Red Kidney Bean (<i>Phaseolus vulgaris</i> L.) Lectins.

Journal of agricultural and food chemistry·2024
Same author

Exploring the dual role of anti-nutritional factors in soybeans: a comprehensive analysis of health risks and benefits.

Critical reviews in food science and nutrition·2024
Same author

Blended Tele-mentoring Support for Strengthening Antenatal Care by Private Health care Facilities: FOGSI VISTRIT INITIATIVE.

Journal of obstetrics and gynaecology of India·2024

Related Experiment Video

Updated: Jun 24, 2026

Source and Route of Pyrrolizidine Alkaloid Contamination in Tea Samples
06:04

Source and Route of Pyrrolizidine Alkaloid Contamination in Tea Samples

Published on: September 28, 2022

Seasonal variations of phenolic compounds in Australia-grown tea (Camellia sinensis).

Lihu Yao1, Nola Caffin, Bruce D'Arcy

  • 1South China Botanic Garden, The Chinese Academy of Sciences, Guangzhou ReYiJu 510650, People's Republic of China.

Journal of Agricultural and Food Chemistry
|August 4, 2005
PubMed
Summary

Seasonal variations significantly impact phenolic compounds in Australian tea leaves. Epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) levels are higher in warmer months, suggesting their use as quality indicators.

More Related Videos

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment
04:36

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Published on: May 26, 2023

Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology
07:05

Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology

Published on: August 23, 2024

Related Experiment Videos

Last Updated: Jun 24, 2026

Source and Route of Pyrrolizidine Alkaloid Contamination in Tea Samples
06:04

Source and Route of Pyrrolizidine Alkaloid Contamination in Tea Samples

Published on: September 28, 2022

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment
04:36

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Published on: May 26, 2023

Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology
07:05

Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology

Published on: August 23, 2024

Area of Science:

  • Agricultural Science
  • Food Chemistry
  • Plant Physiology

Background:

  • Phenolic compounds, particularly flavanols, are key contributors to tea quality and possess health benefits.
  • Understanding seasonal variations in these compounds is crucial for optimizing tea cultivation and processing.
  • Australia is an emerging region for tea production, necessitating localized quality assessment methods.

Purpose of the Study:

  • To investigate the seasonal variations of major phenolic compounds in fresh tea shoots grown in Australia.
  • To identify potential quality descriptors and indices for monitoring seasonal phenolic changes in Australian tea.
  • To explore the influence of environmental factors on the flavonoid profiles of tea leaves.

Main Methods:

  • High-Performance Liquid Chromatography (HPLC) was employed to analyze phenolic compounds.
  • Samples of fresh tea shoots were collected and analyzed across commercial harvest seasons from April 2000 to May 2001.
  • Key flavanols [epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC)] and grouped phenolics were quantified.

Main Results:

  • Levels of EGCG, ECG, and total catechin gallates (CGs) were significantly higher during warmer months (April-May 2000, Oct-Dec 2000, and up to May 2001) compared to cooler months (July-September 2000).
  • Epigallocatechin (EGC) and total catechins (Cs) showed higher and more consistent levels during cooler months.
  • Significant seasonal variations (P < 0.05) were observed for individual and grouped catechins between cooler and warmer months.

Conclusions:

  • EGCG and ECG are proposed as reliable quality descriptors for monitoring seasonal phenolic variations in Australian tea leaves.
  • The ratio (EGCG + ECG)/EGC is suggested as a valuable index for assessing seasonal differences in flavanol levels.
  • Environmental factors like day length, sunlight, and temperature are likely drivers of these seasonal variations, warranting further controlled studies.