Protein denaturation in pilot scale spray dryer
The aim of this project is to investigate the protein denaturation in a pilot scale spray dryer. The occurrence of protein denaturation is due to external stresses, such as heat. Thus, this project describes a pilot process for obtaining protein isolates from whey protein in powder form via spray...
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| Format: | Undergraduates Project Papers |
| Language: | English |
| Published: |
2010
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| Subjects: | |
| Online Access: | http://umpir.ump.edu.my/id/eprint/2696/ http://umpir.ump.edu.my/id/eprint/2696/1/KIOH_SHIN_FANG.PDF |
| Summary: | The aim of this project is to investigate the protein denaturation in a pilot
scale spray dryer. The occurrence of protein denaturation is due to external stresses,
such as heat. Thus, this project describes a pilot process for obtaining protein
isolates from whey protein in powder form via spray drying process with improved
water solubility and technofunctional properties as well as reduced thermal damage.
The experiment, including varying the inlet air temperature at 100°C and 160°C as
well as utilising the microencapsulation technique using a starch derived
polysaccharide (or known as maltodextrin) to minimize the protein denaturation. The
Reversed phase HPLC (RP-I-IPLC) technique has been applied to measure the
denaturation of proteins in the samples which are with maltodextrin and without
maltodextrin resulting from the spray drying of milk solution at inlet temperature of
100°C and 160°C. The combination of maltodextrin (MD) and fresh milk (FM) is at
standard ratio of FM/MD (9: 1) in order to produce spherical and smooth powder.
Apart from the RP-HPLC method, the SDS-PAGE method also used to analyze the
protein content. The morphology of the milk powders was examined using a
Scanning Electron Microscopy (SEM) while the particle size of milk products can be
easily assessed using Mastersizer with model Scirocco 2000. To determine the
portion of whey protein in the spray dried milk samples, the Total Solid Content
method was employed. Besides, sterilization tests such as detection of Salmonella sp.,
and detection of Escherichia coli sp. along with microbial tests which is Standard
Plate Count Method also applied. The spray-drying process was particularly critical
for inducing some thermal damage but it is hypothesized that the crust formation
which resulting in high particle temperatures while still maintaining a wet core, is
likely to lead to high levels of denaturation up to 55% at high temperature (160 °C).
Stability of a-lactalbumin proved higher as compare with fl-lactoglobulin. The
study reveals that low outlet gas temperatures along with microencapsulation are
required to avoid excessive denaturation of protein which can reduce the protein
denaturation until 16%. Up to 93.2% reduction of the microorganisms also proved
that spray drying is another form of sterilization. |
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