Comparison of tea quality parameters of conventionally and organically grown tea, and effects of fertilizer on tea quality: A mini-review

Abstract

Tea is the most consumed beverage in the world next to water. Organic tea manufacturing has increased worldwide during recent decades owing to the benefits for human well-being and the environment, regardless of the overall lower yields of organic systems. Organic tea is richer in (+)-catechin (C), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG), (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), and amino acids, including proline and gamma-aminobutyric acid, than processed tea from conventional agricultural systems. The majority of free amino acids, including theanine, are lower in organic tea. Tea quality is strongly correlated with catechins, caffeine, volatile compounds, and amino acids in harvestable tea shoots. Reliable information on the quality of tea comparing conventional and organic systems is scarce because of the investigational strains in comparing these two systems from different sites. This mini-review highlights the recently published evidence on quality parameters of organic and conventionally grown tea and offers readers scientific evidence as to whether the differentiation is possible.

Keywords

• Organic tea
• Conventional tea
• Black tea quality
• Green tea quality
• Fertilizer
• Nitrogen