Effect of modified resistant starch of culinary banana on physicochemical, functional, morphological, diffraction, and thermal properties

Figures & data

Table 1. Chemical compositions (% dry weight basis) of culinary banana starch.

Starch yield	Starch purity	Moisture content	Ash	Crude fiber	Fat	Protein	pH	Amylose	Resistant starch content
16.00 ± 0.12	96.00 ± 0.08	10.90 ± 0.03	0.35 ± 0.01	0.27 ± 0.09	0.50 ± 0.02	0.31 ± 0.03	6.70 ± 0.03	34.10 ± 0.020.02	18.88 ± 0.05

Results are mean of three replicates ± SD.

Table 2. Water holding capacity, swelling and solubility profile of culinary banana starch (%).

Parameters	Temperature (°C)
	60	70	80	90
Water holding capacity	12.64 ± 0.09	20.42 ± 0.07	36.26 ± 0.01	42.24 ± 0.01
Swelling (gH2O/g dry samples)	2.30 ± 0.12	4.50 ± 0.04	8.90 ± 0.00	12.80 ± 0.06
Solubility	1.55 ± 0.01	3.51 ± 0.52	7.11 ± 0.08	9.00 ± 0.17

Results are mean of three replicates ± SD.

Figure 1. A: Culinary banana at matured edible stage and B: starch from culinary banana.

Figure 2. A: Freeze-thaw stability of culinary banana starch and B: paste-clarity of culinary banana starch.

Figure 3. Pasting properties of culinary banana starch.

Figure 4. X-ray diffractogram of culinary banana starch.

Figure 5. FT-IR spectra of culinary banana starch.

Figure 6. Scanning electron micrograph of culinary banana starch.

Figure 7. TGA and DTG curves of culinary banana starch.

Table 3. Effect of starch concentration and number of autoclaving and cooling cycles on RS content.

Starch concentration [% (w/v)]	Number of cycles	RS content (%)
10	1	9.45 ± 0.75^a
10	2	10.23 ± 0.06^b
10	3	12.30 ± 0.09^d
20	1	11.98 ± 0.14^c
20	2	14.00 ± 0.01^e
20	3	23.31 ± 0.67^f

Results are mean of three replicates ± SD.

Mean followed by same superscript small letters within a column are not significantly different (p > 0.05).

Figure 8. Resistant starch (RS) obtained by A: hydrothermal process and B: enzyme debranching.

Table 4. Effect of storage temperature on resistant starch content.

Resistant starch (RS)	Sample code	Storage (°C)	RS (%)
Autoclaving and cooling (10%)	RS10-A	4	12.30 ± 0.05^a
Autoclaving and cooling (10%)	RS10-B	–20	15.43 ± 0.07^b
Autoclaving and cooling (20%)	RS20-A	4	23.79 ± 0.0^c
Autoclaving and cooling (20%)	RS20-B	–20	26.42 ± 0.12^d
Enzyme debranched (24h)	RSEz-A	4	30.20 ± 0.0^e
Enzyme debranched (24 h)	RSEz-B	–20	31.17 ± 0.01^f

Results are mean of three replicates ± SD.

Mean followed by same superscript small letters within a column are not significantly different (p > 0.05).

Table 5. Chemical compositions (% dry weight basis) of culinary banana RS.

Sample code	Moisture content (wb)	Ash	Crude fiber	Fat	Protein
RS10-A	5.63 ± 0.07^e	0.16 ± 0.95^c	4.23 ± 0.07^a	0.13 ± 0.21^a	0.26 ± 0.75^d
RS10-B	4.65 ± 0.09^a	0.18 ± 0.09^a, b	5.26 ± 0.56^b	0.11 ± 0.09^a	0.35 ± 0.08^c
RS20-A	5.97 ± 1.03^f	0.15 ± 0.32^a	5.79 ± 0.23^c	0.15 ± 0.05^a	0.24 ± 0.09^d
RS20-B	4.92 ± 1.21^b	0.14 ± 0.67^d	5.81 ± 0.04^d	1.21 ± 0.78^d	0.21 ± 0.04^d
RSEz-A	5.33 ± 0.99^d	0.22 ± 0.09^a	6.01 ± 0.01^e	0.78 ± 1.07^c	0.41 ± 0.12^b
RSEz-B	5.01 ± 1.06^c	0.21 ± 0.05^a	6.15 ± 0.75^f	0.64 ± 0.76^b	0.46 ± 0.08^a

Results are mean of three replicates ± SD.

Mean followed by same superscript small letters within a column are not significantly different (p > 0.05).

Figure 9. Scanning electron micrograph of culinary banana RS A: (RS_10-B = 10%, –20°C); B: (RS_20-B = 20%, –20°C); and C: (RS_Ez-B = 24 h, –20°C).

Figure 10. FT-IR spectra of RS obtained after hydrothermal (RS_10-B = 10%, –20°C and RS_20-B = 20%, –20°C) and enzyme debranched (RS_Ez-B = 24 h, –20°C).

Figure 11. TGA and DTG curves of RS obtained after hydrothermal (RS_10-B = 10%, –20°C and RS_20-B = 20%, –20°C) and enzyme debranched (RS_Ez-B = 24 h, –20°C).