Structural and physicochemical properties of banana resistant starch from four cultivars

Figures & data

Figure 1. Optical microscopy, polarized light microscopy, and scanning electron microscopy images of resistant starch samples isolated from four banana cultivars. (a–d: Optical microscopy images (200×); A–D: polarized light microscopy images (200×); I–IV: scanning electron microscopy images (500×).

Table 1. Analysis of x-ray diffraction spectra of resistant starch samples isolated from four banana cultivars.

Banana cultivars	2θ ( ° )	I/I0 (%)	Intensity	Absolute /relative degrees of crystallinity (%)
Musa AAA Cavendish	5.553	13.7	W+	49.6^C ± 0.5/35.0^c ± 0.4
	10.147	6.8	W
	11.426	10.5	W
	15.019	64.7	M
	17.125	100	S
	23.029	39.5	M
Musa ABB Bluggoe	5.675	57.9	M	46.0^D ± 0.5/39.4^b ± 0.5
	11.427	9.5	W
	15.011	48.3	M
	17.086	100	S
	24.113	39.2	M
	26.382	9.9	W
Musa ABB Pisan Awak	5.754	37.0	M	76.6^A ± 0.6/40.9^a ± 0.6
	10.183	4.0	W
	11.495	7.4	W
	14.973	22.7	M-
	17.127	100	S
	19.678	11.8	W
	22.231	29.6	M-
	23.992	26.9	M-
	26.389	12.5	W
Musa AA Pisang mas	5.669	13.8	W+	53.6^B ± 0.6/26.7^d ± 0.6
	9.933	5.2	W
	11.423	7.8	W
	14.937	15.4	M-
	16.97	100	S
	19.443	9.6	W
	22.109	23.8	M-
	24.075	23.2	M-
	26.032	10.3	W

*I/I₀: relative intensity; take the highest peak as the normalization standard to calculate the relative intensity.

S: strong peak; M: middle peak; W: weak peak.

“–” indicates a little weak; “+” indicates a little strong.

Absolute and relative degrees of crystallinity: Mean of three replicates ± standard error.

Values followed by the same letter in the same row are not significantly different (p < 0.05). Capital letters are the comparison results of absolute crystallinity.

Lowercase letters are the comparison results of relative crystallinity.

Figure 2. X-ray diffraction spectra of resistant starch samples isolated from four banana cultivars.

Table 2. The water-holding capacity, solubility, swelling power, and transparency of resistant starch samples isolated from four banana cultivars*.

Physicochemical Properties	Temperature (°C)	Banana cultivars
		Musa AAA Cavendish	Musa ABB Bluggoe	Musa ABB Pisan Awak	Musa AA Pisang mas
Water-holding capacity (%)	50	1.093 ± 0.014^Cc	1.172 ± 0.021^Bbc	1.219 ± 0.013^Cb	1.339 ± 0.020^Ca
	70	1.131 ± 0.016^Bd	1.205 ± 0.027^Bc	1.274 ± 0.011^Bb	1.418 ± 0.025^Ba
	90	2.513 ± 0.012^Ac	2.505 ± 0.021^Ac	3.213 ± 0.014^Ab	4.696 ± 0.023^Aa
Solubility (%)	50	1.50 ± 0.04^Cc	1.10 ± 0.07^Bd	2.57 ± 0.05^Bb	8.20 ± 0.08^Ba
	70	1.69 ± 0.05^Bc	1.19A ± 0.05^Bc	3.56 ± 0.06^Bb	8.68 ± 0.04^Aa
	90	5.31 ± 0.05^Ac	1.29 ± 0.04 ^Ad	9.70 ± 0.07^Aa	8.69 ± 0.05^Ab
Swelling power (%)	50	88.32 ± 3.47^Aab	92.62 ± 3.79^Aab	96.98 ± 2.13^Aa	85.12 ± 3.03^Ab
	70	87.76 ± 3.27^Ab	93.55 ± 3.46^Aab	98.04 ± 2.42^Aa	90.44 ± 3.68^Aab
	90	85.13 ± 4.18^Ab	89.64 ± 3.82^Aab	97.96 ± 2.27^Aa	82.45 ± 3.15^Ab
Transparency (%)	room temperature	2.896 ± 0.006^a	1.955 ± 0.004^c	2.727 ± 0.004^b	1.227 ± 0.003^d

*Mean of three replicates± standard error.

Values followed by the same letter are not significantly different (p < 0.05).

Capital letters are the comparison results of resistant starch from some banana cultivars at different temperatures.

Lowercase letters are the comparison results of resistant starch from different banana cultivars at the same temperature.

Figure 3. Starch-iodine absorption spectra of resistant starch samples isolated from four banana cultivars.

Table 3. Characteristic parameters of the viscosity of resistant starch samples isolated from four banana cultivars.

Banana cultivars	A (ºC)	B (BU)	C (BU)	D (BU)	E (BU)	F (BU)	C–D (BU)	E–F (BU)	E–D (BU)
Musa AAA Cavendish	78.8 ± 0.5^a	498 ± 35^a	490 ± 36^a	377 ± 40^a	588 ± 33^a	519 ± 26^a	113	69	211
Musa ABB Bluggoe	79.9 ± 0.7^a	326 ± 20^c	317 ± 34^c	271 ± 32^b	362 ± 23^b	323 ± 28^b	46	39	91
Musa ABB Pisan Awak	65.5 ± 1.0^c	302 ± 26^c	300 ± 26^c	240 ± 35^b	329 ± 22^b	293 ± 20^b	60	36	89
Musa AA Pisang mas	75.2 ± 0.9^b	439 ± 24^b	429 ± 22^b	225 ± 25^b	355 ± 22^b	327 ± 30^b	204	28	130

A: initial gelatinization temperature; B: peak viscosity (BU); C: viscosity at 95ºC (BU); D: viscosity after 30 min at 95ºC (BU); E: viscosity at 50ºC (BU); F: viscosity after 30 min at 50ºC (BU); C–D: heat stability; F–E: cold stability; E–D: setback.

BU: Brabender unit.

*Mean of three replicates ± standard error.

Values followed by the same letter in the same list are not significantly different (p < 0.05).