Effect of Preservation Methods on Physicochemical Quality, Phenolic Content, and Antioxidant Activity of Stevia Leaves

Table 2

Influence of different preservation treatments and storage period on chlorophyll content of stevia leaves.

	Chl a (mg/g)	Chl b (mg/g)
Before storage
C	13.72 ± 0.6^b	5.94 ± 0.5^b
FD	19.51 ± 0.6^a	6.07 ± 0.17^a
GI at 0.5 kGy	10.69 ± 0.5^c	4.55 ± 0.2^ac
GI at 1 kGy	9.2 ± 0.2^c	3.88 ± 0.2^c
GI at 2 kGy	7.17 ± 0.2^d	4.76 ± 0.1^c
After 10 months of storage
C	6.38 ± 0.3^e	2.39 ± 0.09^d
FD	10.01 ± 0.5^c	4.83 ± 0.4^c
GI at 0.5 kGy	2.77 ± 0.2^f	1.76 ± 0.01^d
GI at 1 kGy	2.00 ± 0.2^f	1.34 ± 0.01^d
GI at 2 kGy	2.50 ± 0.2^f	1.21 ± 0.01^d

The results are expressed as mean ± standard deviation. Different letters in the same column indicate significant statistical differences. The significant differences at a level of 5% were performed by Tukey’s test. C: commercial; FD: freeze-dried; GI: gamma-irradiated.