Effect of enzymatic hydrolysis of starch on pasting, rheological and viscoelastic properties of milk-barnyard millet (Echinochloa frumentacea) blends meant for spray drying.
The influence of enzymatic hydrolysis of starch on the pasting properties of barnyard millet was studied using a rheometer. The effects of blending hydrolyzed barnyard millet wort with milk at different ratios (0:1, 1:1, 1:1.5 and 1:2) on flow and viscoelastic behavior were investigated. From the pasting curves, it was evident that enzymatically-hydrolyzed starch did not exhibit typical pasting characteristics expected of normal starch. The Herschel-Bulkley model fitted well to the flow behaviour data, with coefficient of determination (R(2)) ranging from 0.942 to 0.988. All milk-wort blends demonstrated varying degree of shear thinning with flow behavior index (n) ranging from 0.252 to 0.647. Stress-strain data revealed that 1:1 blend of milk to wort had the highest storage modulus (7.09-20.06Pa) and an elastically-dominant behavior (phase angle <45°) over the tested frequency range. The crossover point of G' and G" shifted to higher frequencies with increasing wort content. From the flow and viscoelastic behavior, it was concluded that the 1:1 blend of milk to wort would have least phase separation and better flowability during spray drying.
ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru-560030, India.
P Arun
PA
Kumar
ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru-560030, India. Electronic address: heartwin1@gmail.com.
Heartwin A
HA
Pushpadass
ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru-560030, India.
Magdaline Eljeeva Emerald
ME
Franklin
ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru-560030, India.
H V Vikram
HV
Simha
ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru-560030, India.
B Surendra
BS
Nath
D001236:Aspergillus oryzae / Q000737:chemistry*; D031747:Echinochloa / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D006868:Hydrolysis; D012212:Rheology; D013213:Starch / Q000737:chemistry*; D014783:Viscosity; D000516:alpha-Amylases / Q000737:chemistry*
D005656:Fungal Proteins; D013213:Starch; D000516:alpha-Amylases
Barnyard millet; Enzymatic hydrolysis; Milk; Pasting; Rheology; Viscoelasticity