Athermal extraction of green tea: Optimisation and kinetics of extraction of polyphenolic compounds.

Murugesh, C. S. and Rastogi, N. K. and Subramanian, N. (2018) Athermal extraction of green tea: Optimisation and kinetics of extraction of polyphenolic compounds. Innovative Food Science & Emerging Technologies, 50. pp. 207-216. ISSN 1466-8564

PDF Innovative Food Science & Emerging Technologies Volume issue 2018.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

An efficient athermal extraction process for green tea, subduing the inherent disadvantage of low yield has been proposed. This process attained 90% total polyphenolic compounds and 96% extractable solids comparable with the conventional hot extraction. The extraction followed two-stage kinetics. A mathematical model with a new approach describing the kinetics of the second stage and extending the predictability to the yield of total polyphenolic compounds inclusive of the instantaneous first stage was deduced from fundamental mass transfer kinetics. The experimental data fitted well with the model (R2 0.941–0.999; RMSE 0.055–0.336). The overall mass transfer coefficient increased from 0.112 to 0.207 min−1 with a particle size reduction from 1.96 to 0.108 mm. The EC50 of DPPH radical scavenging activities of both cold (6.20 μg/mL) and hot extract (5.45 μg/mL) favourably compared with Trolox® (5.20 μg/mL). The cold extracted tea possessed superior organoleptic quality, having a bearing in the ready-to-drink tea preparation. Industrial relevance Cold brewed green tea has been reported to be superior in organoleptic characteristics and possesses similar or superior bioactivity compared to hot brewed tea. Low yield of cold extraction is the most prominent limiting factor in its industrial adoption. The proposed athermal extraction process could overcome this drawback and make the cold extraction industrially viable while offering a superior product.

Item Type:	Article
Uncontrolled Keywords:	Green tea; cold extraction; mathematical model; particle size; catechins; polyphenols
Subjects:	600 Technology > 07 Beverage Technology > 08 Tea 600 Technology > 08 Food technology > 01 Analysis
Divisions:	Food Engineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	05 Feb 2019 08:38
Last Modified:	05 Feb 2019 08:38
URI:	http://ir.cftri.res.in/id/eprint/13921

Actions (login required)

View Item