Effects of the Incorporation of Hydrogen and Nitrogen into Milk on the Reducing and Acidification Capacities of Yoghurt Bacteria

Table 1

Acidification and reducing capacities of Lactobacillus delbrueckii subsp. bulgaricus (LB), Streptococcus thermophilus (ST), and mixed culture of mixed LB + ST inoculated in control, N₂- or H₂-incorporated milk samples during an incubation period of 12 h at 43°C.

Strains	Acidification capacity (pH unit/min)
	Control	N2	H2
Lactobacillus delbrueckii subsp. bulgaricus	^aA; ()	^aB; ()	^aA; ()
Streptococcus thermophilus	^bB; ()	^aC; ()	^aB; ()
Lactobacillus delbrueckii subsp. bulgaricus + Streptococcus thermophilus	^aA; ()	^aA; ()	^aA; ()
	Reducing capacity (mV/min)
Lactobacillus delbrueckii subsp. bulgaricus	^bB; ()	^cB; ()	^aA; ()
Streptococcus thermophilus	^aB; ()	^bC; ()	^aB; ()
Lactobacillus delbrueckii subsp. bulgaricus + Streptococcus thermophilus	^aA; ()	^Aa; ()	^aA; ()

Different small letters on the same row indicate a significant difference between gas conditions (). Different capital letters on the same column indicate a significant difference between strains (). Values in brackets represent pH unit/h and mV/h.