Optimization of extrusion cooking process parameters to develop teff (Eragrostis (Zucc) Trotter)-based products: Physical properties, functional properties, and sensory quality

Figures & data

Table 1. Raw material blends proportion

Code	Blending proportion
BR1 BR2 BR3	90% Teff 10% Chickpea 85% Teff 15% Chickpea 80% Teff 20% Chickpea

Figure 1. Contour plots for an expansion ratio of extrudates as a function of (a) moisture content (MC), blending ratio (BR), and (b) moisture content (MC) barrel temperature (BT).

Figure 2. Contour plots for density as a function of (a) moisture content (MC), blending ratio (BR), (b) moisture content (MC), and barrel temperature (BT).

Figure 3. Contour plots for the hardness of extrudate as a function of (A) moisture content (MC), blending ratio (BR), (B) moisture content (MC), barrel temperature (BT), and (C) blending ratio (BR), and barrel temperature (BT).

Figure 4. Contour plots for WAI as a function of (A) moisture content (MC), blending ratio (BR), (B) moisture content (MC), and barrel temperature (BT).

Figure 5. Contour plots for WSI as a function of moisture content (MC) and barrel temperature (BT).

Table 2. Sensory quality evaluations of the extrudate

	Independent process parameters					Sensory attributes
S/N	x1	x2	x3	x4	Color	Appearance	Flavor	Crispness	OAA
1	−1	−1	0	0	5.35±1.08^cdefg	4.40±1.72^j	5.50±0.82^ab	5.75±1.37^abcdef	5.10±0.91^cdefg
2	1	−1	0	0	5.55±0.68^bcdef	5.05 ±0.88^defghi	4.35±1.08^fg	5.30±1.08^defgh	4.95 ±0.88^defg
3	−1	1	0	0	5.20±1.19^efgh	5.20±1.00^bcdefghi	4.10±1.58^g	5.30±1.55^defgh	4.95±0.99^defg
4	1	1	0	0	4.90±0.91^ghi	4.80±0.76^ghij	4.65±0.67^efg	5.35±1.34^cdefgh	4.80±0.83^fg
5	−1	0	−1	0	6.30±0.92^a	5.90 ±1.58^ab	4.70±1.34^defg	4.95±1.50^fghi	4.85 ±1.56^efg
6	1	0	−1	0	4.70±1.03^hij	4.55±1.19^ij	4.95±0.99^bcdef	3.40±2.01^j	4.80 ±1.10^fg
7	−1	0	1	0	5.75±1.58^abcde	5.55±1.09^abcdef	5.35±1.30^abcd	6.15±0.81^abcd	5.45±0.88^bcd
8	1	0	1	0	4.90±0.71^ghi	5.00 ±0.85^efghij	5.15±0.81^abcde	5.40±0.94^cdefgh	5.15±0.67^bcdefg
9	−1	0	0	−1	5.40±1.04^cdefg	5.05±1.19^defghij	4.80±0.83^bcdef	5.30±1.30^defgh	4.95 ± 0.60^defg
10	1	0	0	−1	5.40±0.59^cdefg	5.60±0.50^abcdef	5.20±0.52^abcde	5.20±1.15^efgh	5.40±0.59^bcde
11	−1	0	0	1	5.85±0.48^abcd	5.70±0.65^abcde	5.50±0.68^ab	5.35±1.13^cdefgh	5.50 ±0.82^bcd
12	1	0	0	1	5.25 ±1.25^defgh	5.30±0.97^bcdefgh	4.65±1.89^efg	5.45±1.60^cdefgh	4.75 ±1.25^g
13	0	−1	−1	0	5.25±0.85^defgh	4.40 ±1.39^j	5.20±1.36^abcde	5.30±1.78^defgh	4.75 ±1.40 ^g
14	0	1	−1	0	6.30±0.86^a	6.05 ±0.75^a	5.40±0.68^abc	4.75±1.74^ghi	5.45 ±0.68^bcd
15	0	−1	1	0	4.55±1.09^ijk	4.90 ±1.11^fghij	5.20±1.05^abcde	4.60±1.90^hi	4.75 ± 1.16^g
16	0	1	1	0	5.55±0.68^bcdef	4.95±1.23^fghij	5.55±0.82ab	5.65±1.53^bcdef	5.35 ±0.87^bdcef
17	0	−1	0	−1	4.05±1.27^k	4.75 ±1.44^hij	5.20±1.05^abcde	4.65±1.66^ghi	4.85 ± 1.03^efg
18	0	1	0	−1	5.25±0.78^defgh	5.05 ±1.05^defghij	5.60±0.94^ab	6.40±0.50^ab	5.35±0.81^bcdef
19	0	−1	0	1	4.10±1.25^jk	4.55±1.57^ij	5.55±0.88^ab	5.50±1.31^cdefg	5.30±0.92^bcdefg
20	0	1	0	1	5.10 ±2.02^fghi	4.70 ±1.49^hij	4.65±1.13^efg	4.15±1.78^ij	4.85±1.18^efg
21	0	0	−1	−1	5.60±0.82^bcdef	4.65±1.22^hij	5.15±1.30^abcde	5.85±1.13^abcde	5.20±0.61^bcdefg
22	0	0	1	−1	6.15±0.48^ab	5.75±0.91^abdc	5.75±0.96a	6.55±0.68^a	6.15±0.67^a
23	0	0	−1	1	5.80±0.76^abcde	5.80 ±0.76^abc	5.75±0.63a	6.10±1.20^abcd	5.60±0.88^abc
24	0	0	1	1	5.90 ±0.71^abc	5.50±0.88^abcdefg	5.25±0.85^abcde	6.15±0.87^abcd	5.70±0.47^ab
25	0	0	0	0	5.50±0.60^cdefg	5.10 ±1.16^cdefghij	5.55±0.82ab	6.20±1.19^abc	5.60±0.88^abc

All figures are averages of triplicate ± standard deviation; figures in the same column with dissimilar alphabets show notable differences (p ≤ 0.05); where OAA-Overall acceptability; Coded levels of parameters (X1, X2, X3, and X4); Factors (FMC, BR, BT, and SS); where X1- FMC (%), X2- BR/Blend ratio, X3- BT (0^C) Barrel temperature and X4-SS (rpm) screw speed.