. 2015 Sep;53(3):307–314. doi: 10.17113/ftb.53.03.15.4043

Table 2. The pH and titratable acidity during fermentation and storage of whey drinks produced using liquid whey protein concentrates and ultrafiltrated and concentrated permeates with kefir grains, commercial mix of probiotics, and kefir grains combined with commercial mix of probiotics.

Parameter	t/h	LWPC			UFCP
		k	p	k+p	k	p	k+p
pH	0	(5.5±0.1)^c	(5.4±0.1)^c	(5.37±0.06)^c	(4.80±0.05)^c	(4.80±0.04)^c	(4.79±0.01)^c
	24	(4.47±0.06)^b	(4.47±0.06)^b	(4.33±0.06)^ab	(4.43±0.06)^b	(4.7±0.1)^c	(4.1±0.1)^a
	168	(4.25±0.05)^a	(4.15±0.05)^a	(4.19±0.01)^a	(4.38±0.03)^b	(4.43±0.06)^b	(4.1±0.1)^a
TA·10²/%	0	(3.9±0.1)^a	(4.00±0.06)^a	(3.97±0.08)^a	(0.73±0.03)^a	(0.73±0.03)^a	(0.73±0.03)^a
	24	(8.0±0.1)^cd	(6.9±0.2)^b	(8.6±0.3)^e	(3.2±0.5)^bc	(3.5±0.1)^cd	(2.96±0.04)^b
	168	(8.4±0.2)^de	(7.71±0.09)^c	(8.67±0.05)^e	(3.83±0.02)^d	(2.96±0.03)^b	(2.95±0.05)^b

Different letters in superscript indicate statistically significant differences (p<0.05). LWPC=liquid whey protein concentrate, UFCP=ultrafiltrated and concentrated permeate, k=kefir grains, p=commercial mix of probiotics, k+p=kefir grains with commercial mix of probiotics, TA=titratable acidity as percentage of lactic acid