Abstract:
Despite its global reputation, Sri Lankan green tea faces microbiological quality
concerns. This study evaluated the microbiological and sensory quality of Sri Lankan
green tea produced by steaming, panning, handcrafting methods and examined
compliance with Sri Lanka Tea Board standards. Green tea samples were collected
from 15 operational green tea factories (n=15) during 2025, with three replicate
samples obtained from each factory. Microbiological analyses followed ISO
11287:2011. Each sample was analyzed in triplicate for Total Plate Count (ISO 4833-
1:2013), Yeast & Mold (ISO 21527-2:2008), Total Coliforms (ISO 4831:2006) and
Escherichia coli (ISO 7251:2005). Sensory evaluation used a seven-point hedonic scale
by seven trained tea tasters from Sri Lanka Tea Board, assessing dry leaf, liquor, and
infused leaf quality. Statistical analyses were performed using IBM SPSS Statistics
version 27. One-way ANOVA followed by Tukey’s post hoc test was used to compare
microbiological and sensory parameters among manufacturing methods at p<0.05.
The handcrafted method recorded the lowest mean yeast and mold count (6.19×10²
CFU/g), total plate count (3.39×10² CFU/g), and total coliform count (4.35×102
MPN/g) and the highest sensory quality (p = 0.002). In contrast, the panning method
showed the highest microbial loads, with yeast and mold counts of 4.21×10⁵ CFU/g and
total plate counts of 8.15×10⁵ CFU/g, while steaming had moderate levels, yeast and
mold counts (1.20×10⁵ CFU/g) and total plate counts (5.45×10⁵ CFU/g). Although all
green tea samples were free from Escherichia coli, a substantial proportion failed to
comply with the microbiological safety limits of Sri Lanka Tea Board Circular ALMQS-
02/2021; however, samples were complied with the Tea & Herbal Infusions Europe
(THIE) recommended microbiological limits for Camellia sinensis with minor yeast and
mold deviations. These findings highlight the improved sanitation and quality control,
particularly in automated manufacturing systems. Overall, handcrafted green tea
demonstrated superior quality compared to other manufacturing methods.
