Abstract #M119
Section: Dairy Foods (posters)
Session: Dairy Foods - Products
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A
Session: Dairy Foods - Products
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A
# M119
Influence of β-galactosidase and temperature treatment to milk on functional and reconstitution properties of low-lactose milk powders by spray drying.
S. Ditudompo*1, J. Peepanich1, S. Jarnpim1, T. Kunanopparat2, S. Rungchang3, 1Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, Nakhon Nayok, Thailand, 2Department of Food Engineering, King Mongkut's University of Technology Thonburi, Bangkok, Thailand, 3Department of Agro-Industry, Naresuan University, Phitsanulok, Thailand.
Key Words: β-galactosidase, low-lactose milk powder, spray drying
Influence of β-galactosidase and temperature treatment to milk on functional and reconstitution properties of low-lactose milk powders by spray drying.
S. Ditudompo*1, J. Peepanich1, S. Jarnpim1, T. Kunanopparat2, S. Rungchang3, 1Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, Nakhon Nayok, Thailand, 2Department of Food Engineering, King Mongkut's University of Technology Thonburi, Bangkok, Thailand, 3Department of Agro-Industry, Naresuan University, Phitsanulok, Thailand.
The aim of this study was to determine effects of β-galactosidase and temperature treatments to milk on functional and reconstitution properties of low-lactose milk powders (lactose <0.1%). Skim milk mixed with 5000 NTU/L of β-galactosidase were incubated at 4, 35 and 50°C, which was stirred for 1 h and then stored under refrigeration at 4°C for 20 h before spray drying at the inlet and outlet air temperatures of 170/85°C. Hydrolyzed lactose milk powder (HLMP) was darker than unhydrolyzed lactose milk powder (control) because of the greater amount of reducing sugars, which causes the Maillard reaction. HLMP had higher redness (a*) value and lower water activity compared with the control (P < 0.05). HLMP had no significant effect on lightness (L*) and yellowness (b*) values, moisture content and bulk density. In addition, HLMP led to a reduction in wettability and dispersibility, which means that HLMP is difficult in rehydration (P < 0.05). As the incubation temperature increased, the rate of glucose released also increased. Bulk density was increased and wettability and dispersibility were decreased with increase in the incubation temperature (P < 0.05). Incubation temperature had no significant effect on color, moisture content and water activity of HLMP. According to Carr’s index and Hausner ratio values, the flowability of the control and HLMP incubated at 4°C were “poor,” while HLMP incubated at 35 and 50°C were “very poor.” The results revealed that the increase in the rate of lactose hydrolysis resulted in a larger agglomeration of particles. This could explain the decrease in the rehydration capacity of the powders.
Table 1 (Abstr. M119). Functional and reconstitution properties of low-lactose milk powders incubated at different temperatures (4°C, 35°C, and 50°C)
a–cMeans within a row with different superscripts are significantly different (P < 0.05).
| Untreated | β-galactosidase | ||||
| 4°C | 4°C | 35°C | 50°C | ||
| Water activity | 0.26a ± 0.02 | 0.21b ± 0.01 | 0.21b ± 0.01 | 0.23ab ± 0.02 | |
| L* Ns | 91.38 ± 7.47 | 91.15 ± 7.45 | 90.66 ± 7.44 | 91.04 ± 7.44 | |
| a* | −1.12b ± 0.10 | −0.51a ± 0.05 | −0.59a ± 0.06 | −0.64a ± 0.07 | |
| b* Ns | 7.21 ± 0.61 | 7.78 ± 0.65 | 7.60 ± 0.64 | 7.72 ± 0.64 | |
| Wettability (s) | 175.3a ± 11.3 | 136.0b ± 10.3 | 43.3c ± 3.7 | 44.4c ± 2.6 | |
| Dispersibility (%) | 202.9a ± 23.5 | 135.0b ± 11.0 | 120.0bc ± 9.8 | 97.1c ± 6.4 | |
Key Words: β-galactosidase, low-lactose milk powder, spray drying
