dr.r.parimalavalli
TRANSCRIPT
R. Parimalavalli & S. Kavitha Department of Food Science and Nutrition
Periyar University Salem - 636 011
Complementary food is defined as those which are
appropriately timed, nutritionally adequate and
hygienically prepared foods that are given to
infants along with continued breast feeding from
six months of age. Extrusion cooking is one of the contemporary food
processing technologies applied for preparation of
a variety of snacks and supplementary foods.
To analyze the physical, morphological and sensory
characteristics of Ready-to-Eat (RTE) extruded
complementary foods.
Procurement of Raw Materials (Wheat, maize, Mung bean and
Groundnut)
Procurement of Raw Materials (Wheat, maize, Mung bean and
Groundnut)
Composit ion of Complementary Food by
Material Balance Method (Wheat – 39%, Maize – 34 %,
Mung bean – 14 % and Groundnut – 13 %)
Composit ion of Complementary Food by
Material Balance Method (Wheat – 39%, Maize – 34 %,
Mung bean – 14 % and Groundnut – 13 %)
Processing of Raw Materials Processing of Raw Materials
Physical PropertiesMorphological analysis – SEM
Organoleptic Qual it ies
Physical PropertiesMorphological analysis – SEM
Organoleptic Qualit ies
Extrusion Process – Twin Screw Extruder
Extrusion Process – Twin Screw Extruder
Raw Ingredients
Wheat Maize Mungbean Groundnut
Processing of Raw Ingredients
Composite Flours
Extruded Complementary
Foods
Control GerminationRoasting
Table – 1 Physical Charactersitics of Extruded Complementary foods
CECF – Control Extruded Complementary Food, RECF – Roasted Extruded Complementary Food,
GECF – Germinated Extruded Complementary Food.
Physical Characteristics CECF RECF GECF F Ratio
Length (mm)Diameter (mm)Specific VolumeExpansion RatioMass Flow Rate (gs 1‑ )Residence Time (S)Specific Mechanical Energy (kj/kg)Bulk Density (g/ml)WAI (g/g)WSI (%)
4.94±0.64a
2.60±0.30 a
2.76±0.63 a
3.64±0.13 a
1.36±0.21 a
77.6±1.26 a
818.25±3.65 a
0.96±0.02 a
3.59±0.65 a
16.98±1.21 a
3.88±0.85b
2.47±0.20 b
2.62±0.42 b
3.03±0.57 b
1.13±0.42 b
68.65±1.03 b
864.74±5.68 b
0.94±0.01 b
3.04±0.53 b
15.40±0.98 b
3.71±0.54 c
2.42±0.23 c
2.89±0.35 c
2.43±0.27 c
0.98±0.26 c
54.06±1.12 c
968.31±4.75 c
0.98±0.02 c
4.21±0.45 c
18.64±0.84 c
9.36**3.89*
4.98**8.02**4.89**7.46**9.87**0.09 NS
5.36**6.58**
•CECF had high 4.94 mm length, 2.60mm diameter, 3.64
expansion ratio, 56.25 T, 1.36gs 1‑ MFR and 77.6 sec
residence time. GECF had high 2.89 specific volume,
968.31kj/kg specific mechanical energy, 0.98g/ml bulk
density, 4.21g/g water absorption index and 18.64% water
solubility index.
A - CECF – Control Extruded Complementary Food, B - RECF – Roasted Extruded Complementary Food, C - GECF – Germinated Extruded Complementary Food.
Morphological Analysis of Extruded Complementary foods
A B C
•Absence of starch granule in all samples indicated starch has
been completely gelatinized. Extrudates showed large numbers
of flattened and sheared granules. The highest damage was seen
during extrusion in germinated samples followed by control
and roasted samples.
•Control sample displayed a porous, open celled structure
devoid of air cells may be due to less expansion and high shear
stress.
•Roasted extruded complementary food showed a
discontinuous flattened granular structure with few air cell
embedded inside the layer. A higher air cells in the roasted
extrudate compared to control extrudate indicates that a higher
magnitude of expansion was occurred due to roasting.
•Germinated extrudate displayed a smooth surface morphology
indicated gelatinization of starch component and porous layer.
The outer core of the extrudate appeared to have a protein coat
associated with the starch granules since germinated extruded
complementary food is recorded with a elevated levels of
protein.
Table – 2 Organoleptic Qualities of Extruded Complementary foods
Characteristics CECF RECF GECF
ColourFlavourTasteTextureOverall acceptability
6.52±0.30a
3.59±0.24 a
4.23±0.86 a
4.40±0.92 a
5.01±0.57 a
5.42±0.88 b
4.94±0.46 b
6.70±1.30 b
5.78±0.93 b
7.14±0.91 b
5.06±0.73 c
3.04±0.43 c
5.20±0.86 c
6.04±0.52 c
6.20±0.15 c
•The range of scores for attributes was: colour (4.52 to
5.92), flavour (3.59 to 4.94), taste (4.23 to 6.70),
texture (4.40 to 6.04) and overall acceptability (5.01 to
7.04).
•RECF was highly acceptable with mean score of 7.14.
Their acceptability level was significantly higher
(P < 0.05) than the rest of samples.
Processing methods markedly affect the
physical, morphological and organoleptic qualities
of complementary foods. Hence the processed
energy dense complementary foods could be
formulated at low cost with locally available
cereals and pulses to promote nutritional status of
infants.