Table 3 Comparison of yoghurt production processes for low lactose content

[72]

Cow milk

Fermentation, 41 °C

35%

4.4

Titratable acidity, 1.1%

8 h

Simultaneous, 41 °C

99%, A. oryzae, 0.9 U mL⁻¹, 1 g L⁻¹

0.1

Titratable acidity, 1.0%

8 h

[54]

Cow milk

Fermentation, 39 °C

12.6%

3.9

n.d

7 h

Hydrolysis 4–6 °C, subsequent fermentation 39 °C

98.5%, Bacillus licheniformis, 18.1 U mL⁻¹, 3.3 g L⁻¹

0.3

n.d

4 h + 6.5 h

Simultaneous 39 °C

84.2%, B. licheniformis, 17.3 U mL⁻¹, 3.3 g L⁻¹

0.7

n.d

6 h

[54]

Goat milk

Fermentation, 39 °C

14.0%

3.9

n.d

7 h

Hydrolysis 4–6 °C, subsequent fermentation 39 °C

96.5%, B. licheniformis, 18.1 U mL⁻¹, 3.3 g L⁻¹

0.2

n.d

4 h + 6.5 h

Simultaneous 39 °C

82.7%, B. licheniformis, 17.3 U mL⁻¹, 3.3 g L⁻¹

0.8

n.d

6 h

[31]

Camel milk

Fermentation, 42 °C

27.0%

3.3

Titratable acidity, 0.7%

7.5 h

Hydrolysis 40 °C, 150 rpm, subsequent fermentation, 42 °C

90.0%, K

lactis, 2.6 U mL⁻¹, 0.5 g L⁻¹

0.4

Titratable acidity, 0.8%

5 h + 4.8 h

Simultaneous, 42 °C

71.2%, K

lactis, 2.6 U mL⁻¹, 0.5 g L⁻¹

1.3

Titratable acidity, 0.8%

4.6 h

[77]

Bulk bovine milk

Fermentation, 42 °C

18.7%

3.8

HPLC, 6.9 mg g⁻¹

3.9 h

Simultaneous, 42 °C

91.4%, K. lactis, 0.4 g L⁻¹, activity unknown,

0.4

HPLC, 6.5 mg g⁻¹

4.3 h

[45]

Milk powder

Fermentation, 43 °C

19.8%,

4.6

n.d

3.9 h

Simultaneous, 43 °C

97.9%, K. lactis and

A. niger, 0.5 g L⁻¹ activity unknown,

0.1

n.d

4.3 h