Table 3
Changes in microorganism of birch sap treated under var ious HPP conditions dur ing storage at 5℃ (unit: log CFU)

Microorganism	Sample1)	Storage period (day)
		1	6	15	63
		Total bacteria	Control	4.19±0.012)	6.34±0.04	-	-
BS-1	0.54±0.06		ND3)	ND	3.89±0.01
BS-2	0.50±0.20		0.69±0.09	ND	3.47±0.02
BS-3	0.30±0.00		ND	0.24±0.24 3.50±0.07
BS-4	0.45±0.15		0.98±0.02	0.30±0.00	ND
BS-5	0.77±0.07		1.15±0.11	ND	1.24±0.01
Coliform group	Control	0.80±0.10	1.47±0.01	-	-
	BS-1	ND	ND	ND	ND
	BS-2	ND	ND	ND	ND
	BS-3	ND	ND	ND	ND
	BS-4	ND	ND	ND	ND
	BS-5	ND	ND	ND	ND
E.coil	Control	Negative	Negative	-	-
	BS-1	Negative	Negative	Negative	Negative
	BS-2	Negative	Negative	Negative	Negative
	BS-3	Negative	Negative	Negative	Negative
	BS-4	Negative	Negative	Negative	Negative
	BS-5	Negative	Negative	Negative	Negative

Control, non-treated birch sap; BS-1, birch sap treated with 550 MPa pressure for 30 sec; BS-2, birch sap treated with 550 MPa pressure for 60 sec; BS-3, birch sap treated with 500 MPa pressure for 60 sec; BS-4, birch sap treated with 500 MPa pressure for 120 sec; BS-5, birch sap treated with 450 MPa pressure for 120 sec.
All results are expressed as means for three replicates.
ND, Not detected.