Background:
The extrusion cooking is the most widely used process so the development
and consumption of extruded snack products having health and nutritious benefits would help increase
the health status of the population.
Objective:
The aim of this study was to investigate the effect of storage days on physical, microbial
activity and sensory characteristics of extruded snacks and kinetics of extruded snacks.
Methods:
Extruded snacks were produced by extrusion cooking at optimized conditions of temperature,
moisture and screw speed of 110°C, 12% (db) and 200 rpm. The products were packed in lowdensity
polyethylene (LDPE) and laminated pouches (LP) and were stored at an accelerated temperature
condition of 40 ± 2°C. The storage stability in terms of quality parameters such as moisture,
hardness, bulk density, color, lateral expansion, sensory characteristics and total plate count was investigated.
Results:
An increase (p≤0.05) in the value of moisture, bulk density, a*, and total plate count was
observed during the storage period, whereas hardness, L*, b*, ΔE and sensory characteristics showed
significant (p≤0.05) decreased order with storage period. No significant effect on the lateral expansion
of the extruded product was observed. A significant decrease in total carbohydrate, fat and protein
content was found during the storage period. The average sensory score and microbial analysis
suggested that extruded snacks packed in LDPE pouches can only be acceptable up to the 60th day
and extruded snacks packed in LP can be acceptable to more than 90th day. The kinetics of color and
hardness suggest first order kinetics.
Conclusion:
Overall investigation suggested that extruded snacks were more stable in the LP as
compared to LDPE pouches.
Process optimization of extrusion variables and effects on some quality and sensory characteristics of extruded snacks from whole pearl millet-based flour
