TY  - MANSCPT
AU  - Nuraini Mohd Yusoff
TI  - Influence of maltodextrin addition to thermal stability of whey protein isolate
SN  - THE0007973(Local)
PY  - 2014///
CY  - Kuantan, Pahang
PB  - UMP
KW  - Faculty of Chemical & Natural Resources Engineering
KW  - Dissertations
KW  - Universities and Colleges
KW  - Theses
N1  - Faculty of Chemical & Natural Resources Engineering; Project Paper (Master of Engineering (Bio-Process)) -- Universiti Malaysia Pahang – 2014; Bibliography : p. 94-108
N2  - This thesis presents a thermal denaturation study of whey protein isolate (WPI) with the presence  of  maltodextrin  (MD)  during  heating  experiment  and  spray  drying.  Heating experiment  of  whey  protein  isolate  in  a  closed  stainless  steel  tube  for  30  minutes  at temperature of 80 °C caused a 97.3% and 67.3% denaturation of β-lactoglobulin and α-lactalbumin, respectively. Arrhenius model provides a good fit to experimental data for both α-lac and β-lg denaturation with average error around 5.85% and 5.92%. Addition of maltodextrin improved the thermal stability of β-lactoglobulin and α-lactalbumin, by increasing  its  order  of  reaction  from  1.5  to  3.5  and  by  reducing  the  rate  constant  of denaturation by two orders of magnitude from 10-4 to 10-6. Addition of maltodextrin reduces the thermal  degradation of β-lactoglobulin and α-lactalbumin up to 12.52% and 14.14%, respectively. Formulation of 9:1 WPI to maltodextrin ratio was found to give a better thermal stability for both β-lactoglobulin and α-lactalbumin, compared to the 1:1 ratio.  Addition  of  maltodextrin  to  WPI  solution  reduces  protein  denaturation  during spray drying. The lowest protein denaturation (~4%) was observed when a higher wall to  core  ratio  (1:9  WPI:MD)  was  used,  implying  the  mechanism  of  encapsulation  is  a homogeneous matrix  structure, instead of a big single core structure. For spray drying process  the  optimal  operating  conditions  to  minimise  denaturation  where  3%  solid concentrations, a WPI:MD 1:9, a nozzle size of 1 mm, and inlet temperature 140 °C. The physical properties  of spray dried powder were also affected by temperature, solid concentration, nozzle size and maltodextrin to WPI ratio. Increasing temperature from 140 °C to 190 °C increased the particle size from 8.59 to 9.57 µm, due to increase in particle  surface  evaporation  rate.  The  particle  size  obtained  from  the  formulation consisting  a  higher  WPI  content  (WPI:  MD  9:1)  had  a  bigger  diameter  9.74  µm  as compared to the lower  WPI  content (WPI: MD 1:9) 7.36 µm. The mean particle size increased from 9.72 and 20.84 µm when the total solid content increased from 1.5 to 20 wt.% due to increases in solution viscosity. The powder mean diameters increased from 9.55 µm to 11.48 µm when the nozzle size diameter increases from 0.5 mm to 1.5 mm. Surface morphology of whey protein was affected mainly by the solid concentration and maltodextrin to WPI ratio
ER  -