The fundamental effect of ingredients on the pasting and retrogradation properties of tapioca and corn starch in excess and limited water solvation medium
Samson Raphael
https://urn.fi/URN:NBN:fi-fe2021042824364
Tiivistelmä
Native starches, low cost carbohydrate are employed by
the food industry to control the textural and organoleptic properties of
several starch based foods, such as baby foods, where starch co-exists and interacts
with other food ingredients in the food matrix such as, sugars, acids, salts
and lipids. This interaction unpredictably and unavoidably affects the organoleptic
properties of the final product. This is why these food applications demand the
knowledge of starch pasting and viscosity behaviour, because it is necessary to
control the organoleptic properties of the finished products and also to obtain
consistent viscosity from batch to batch.
The objective of this study was to investigate the
effect of ingredients on the viscoelastic properties of corn and tapioca starch
used in the production of selected baby foods. In this study, the sugars and acids
profile of the cooking medium where the starch is gelatinized was analyzed with
a gas chromatograph coupled with flame ionization detector (GC-FID). The results
were utilized to prepare sugars and acids starch model solutions for a process
simulation to predict starch rheological behaviour. The viscoelastic properties
of experiments were carried out with a Rapid Visco Analyser (RVA).
Experimental results showed that all ingredients
tested had a significant dilatant (shear thickening) phenomenon on the starch
in excess water medium, while on the other hand, in limited water medium, the ingredients
exhibited an inverse effect causing a significant pseudo plastic behaviour (shear
thinning) on the starch samples. Lipids caused a significant thixotropic (shear
thinning) behaviour and were evidently responsible for the irreproducibility of
viscosity profile of starch types when added to the mixture. Acids caused shear
thinning behaviour due to glucose hydrolysis and reduction in the degree of polymerization.
Furthermore, starch lumps were formed in food matrix when starch dispersions
were allowed to sediment and also gelatinized with delayed shearing, causing a
clumping together of starch granules.
It can be concluded that corn and tapioca starch gelatinization
and pasting required for thickening, textural and organoleptic properties of
puree-based baby food matrix gives a better viscoelastic properties in excess
water solvation medium, in comparison to limited water medium, since cooking in
excess water environment has enough solvent externally available for corn and
tapioca amorphous growth ring, therefore resulting in total disruption of
lamellar and crystalline order resulting in a non-thixotropic characteristics
of the finished starch-based puree product.
This study may be used as an applicable model for
starch-based food product development.
Keywords: RVA, GC-FID, sugars and acids, tapioca
starch, corn starch, amylose and amylopectin, ascorbic acid, lipids, salts,
viscosity, pasting and retrogradation.
Kokoelmat
- Rinnakkaistallenteet [19206]