Table 2
Changes in physicochemical proper ties of birch sap treated under various HPP conditions dur ing cold storage at 5℃

Sample1)	Storage period (day)	Sugar contents ( Brix)	Total acidity (%)	pH
Control	1	1.4±0.1^ab	0.042±0.004^a	5.86±0.00^d
	6	1.4±0.0^b	0.045±0.004^a	5.53±0.00^c
	15	1.3±0.1^ab	0.062±0.004^b	4.99±0.00^b
	63	1.3±0.0^a	0.121±0.007^c	4.39±0.00^a
BS-1	1	1.3±0.0^b	0.042±0.004^a	6.04±0.00^d
	6	1.3±0.1^b	0.040±0.000^a	5.98±0.01^c
	15	1.3±0.1^b	0.045±0.004^a	5.85±0.01^b
	63	1.2±0.1^a	0.045±0.004^a	5.38±0.00^a
BS-2	1	1.3±0.0^b	0.025±0.004^a	6.04±0.00^d
	6	1.4±0.1^b	0.027±0.000^a	5.98±0.01^c
	15	1.3±0.0^b	0.029±0.004^a	5.86±0.00^b
	63	1.2±0.1^a	0.038±.003^b	5.65±0.00^a
BS-3	1	1.3±0.1^b	0.027±0.004^a	6.04±0.00^d
	6	1.4±0.1^c	0.027±0.004^a	5.98±0.02^c
	15	1.4±0.1^bc	0.042±0.000^b	5.86±0.02^b
	63	1.2±0.1^a	0.058±0.000^c	5.04±0.03^a
BS-4	1	1.3±0.1^a	0.025±0.004^a	6.04±0.00^d
	6	1.3±0.1^a	0.025±0.004^a	5.98±0.02^c
	15	1.3±0.1^a	0.027±.000^a	5.86±0.02^b
	63	1.2±0.1^a	0.040±0.000^b	5.70±0.01^a
BS-5	1	1.3±0.1^ab	0.025±0.004^a	6.05±0.01^d
	6	1.3±0.1^b	0.040±0.000^b	6.00±0.01^c
	15	1.4±0.1^ab	0.040±0.000^b	5.87±0.01^b
	63	1.2±0.0^a	0.065±0.004^c	4.88±0.02^a

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.
Means±SD (n=3) with different superscript in the each column (HPP condition group) are significantly different (p<0.05) by Duncan’s multiple range test.