Figure 1.
Photographs of nuts from Chinese chestnut variety 3113 (A), Benlizi (B), Dahongpao (C), Erqingzao (D), Heishanzhai 7 (E), Mi 5 (F), Mi 6 (G), Yangguang (H), and Yanshanhong (I). Scale bar = 20 mm.
Figure 1.
Photographs of nuts from Chinese chestnut variety 3113 (A), Benlizi (B), Dahongpao (C), Erqingzao (D), Heishanzhai 7 (E), Mi 5 (F), Mi 6 (G), Yangguang (H), and Yanshanhong (I). Scale bar = 20 mm.
Figure 2.
The morphology of starch granules from variety 3113 under normal light microscope (A), polarized light microscope (B), and scanning electron microscope (C). Scale bar = 10 μm.
Figure 2.
The morphology of starch granules from variety 3113 under normal light microscope (A), polarized light microscope (B), and scanning electron microscope (C). Scale bar = 10 μm.
Figure 3.
XRD patterns of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 3.
XRD patterns of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 4.
ATR-FTIR spectra of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 4.
ATR-FTIR spectra of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 5.
SAXS spectra of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 5.
SAXS spectra of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 6.
DSC thermographs of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 6.
DSC thermographs of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 7.
RVA profiles of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 7.
RVA profiles of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 8.
TGA curves (A) and DTG curves (B) of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 8.
TGA curves (A) and DTG curves (B) of starches from variety 3113 (a), Benlizi (b), Dahongpao (c), Erqingzao (d), Heishanzhai 7 (e), Mi 5 (f), Mi 6 (g), Yangguang (h), and Yanshanhong (i).
Figure 9.
Loading (A) and score plots (B) of principal component analysis based on physicochemical properties of starches from nine Chinese chestnut varieties. The abbreviations in (A) are listed below: AAC, apparent amylose content; D, lamellar distance; D[4,3], volume-weighted mean diameter; IBV, iodine blue value of starch; IR, absorbance ratio of 1045/1022 cm−1 in FTIR spectrum; N-RDS, rapidly digestible starch in native starch; G-RDS, SDS, and RS, rapidly digestible starch, slowly digestible starch, and resistant starch in gelatinized starch; OD620/550, absorbance ratio of OD620 to OD550 in iodine absorbance spectrum of starch; PI, lamellar peak intensity; PV, HV, BV, FV, and SV, pasting peak, hot, breakdown, final, and setback viscosity, respectively; RC, relative crystallinity; SG, volume percentage of small starch granule; To, Tp, and Tc, gelatinization onset, peak, and conclusion temperature, respectively; ΔT, gelatinization temperature range; ΔH, gelatinization enthalpy. The abbreviations of varieties in (B) are listed below: BLZ, Benlizi; DHP, Dahongpao; EQZ, Erqingzao; HSZ; Heishanzhai 7; YG, Yangguang; YSH, Yanshanhong.
Figure 9.
Loading (A) and score plots (B) of principal component analysis based on physicochemical properties of starches from nine Chinese chestnut varieties. The abbreviations in (A) are listed below: AAC, apparent amylose content; D, lamellar distance; D[4,3], volume-weighted mean diameter; IBV, iodine blue value of starch; IR, absorbance ratio of 1045/1022 cm−1 in FTIR spectrum; N-RDS, rapidly digestible starch in native starch; G-RDS, SDS, and RS, rapidly digestible starch, slowly digestible starch, and resistant starch in gelatinized starch; OD620/550, absorbance ratio of OD620 to OD550 in iodine absorbance spectrum of starch; PI, lamellar peak intensity; PV, HV, BV, FV, and SV, pasting peak, hot, breakdown, final, and setback viscosity, respectively; RC, relative crystallinity; SG, volume percentage of small starch granule; To, Tp, and Tc, gelatinization onset, peak, and conclusion temperature, respectively; ΔT, gelatinization temperature range; ΔH, gelatinization enthalpy. The abbreviations of varieties in (B) are listed below: BLZ, Benlizi; DHP, Dahongpao; EQZ, Erqingzao; HSZ; Heishanzhai 7; YG, Yangguang; YSH, Yanshanhong.
Table 1.
Nut and kernel weights and starch content in kernel.
Table 1.
Nut and kernel weights and starch content in kernel.
Varieties | Fresh Nut Weight (g/nut) | Fresh Kernel Weight (g/kernel) | Dry Kernel |
---|
Kernel Weight (g/kernel) | Starch Content (%) |
---|
3113 | 6.4 ± 0.1 a | 5.5 ± 0.1a | 2.51 ± 0.03 a | 43.3 ± 0.2 a,b |
Benlizi | 11.9 ± 0.5 e | 9.9 ± 0.4 d,e | 4.95 ± 0.20 d | 46.7 ± 1.0 b,c |
Dahongpao | 12.2 ± 0.7 e | 10.5 ± 0.5 e | 5.61 ± 0.29 e | 49.2 ± 0.9 c |
Erqingzao | 6.7 ± 0.5 a,b | 5.5 ± 0.4 a | 3.29 ± 0.22 b | 42.7 ± 1.0 a |
Heishanzhai 7 | 7.0 ± 0.2 a,b,c | 6.1 ± 0.2 a,b | 2.98 ± 0.11 b | 47.6 ± 1.5 c |
Mi 5 | 7.9 ± 0.1 c | 6.8 ± 0.1 b | 3.90 ± 0.04 c | 43.6 ± 1.2 a,b |
Mi 6 | 7.7 ± 0.6 b,c | 6.6 ± 0.5 b | 3.16 ± 0.22 b | 46.4 ± 1.0 a,b,c |
Yangguang | 10.6 ± 0.1 d | 9.2 ± 0.2 c,d | 4.29 ± 0.08 c | 49.3 ± 1.2 c |
Yanshanhong | 10.2 ± 0.3 d | 8.7 ± 0.3 c | 4.78 ± 0.17 d | 43.1 ± 0.6 a,b |
Mean ± SD | 9.0 ± 2.3 | 7.6 ± 1.9 | 3.94 ± 1.04 | 45.8 ± 2.7 |
Sig. | 0.160 | 0.205 | 0.802 | 0.137 |
Table 2.
Volume percentage of small starch granules and starch granule size distribution.
Table 2.
Volume percentage of small starch granules and starch granule size distribution.
Varieties | Small Granule (%) | d(0.1) (μm) | d(0.5) (μm) | d(0.9) (μm) | D[4,3] (μm) |
---|
3113 | 11.04 ± 0.05 f | 1.934 ± 0.012 c | 7.431 ± 0.004 e | 13.620 ± 0.008 f | 7.819 ± 0.003 f |
Benlizi | 10.24 ± 0.04 b | 2.156 ± 0.015 f | 7.706 ± 0.001 g | 13.855 ± 0.004 h | 8.048 ± 0.001 g |
Dahongpao | 10.70 ± 0.04 e | 1.988 ± 0.011 d | 7.291 ± 0.001 d | 13.073 ± 0.004 c | 7.607 ± 0.001 d |
Erqingzao | 11.27 ± 0.06 g | 1.776 ± 0.016 b | 6.901 ± 0.002 a | 12.241 ± 0.001 a | 7.170 ± 0.003 a |
Heishanzhai 7 | 10.60 ± 0.03 d | 2.264 ± 0.013 g | 7.911 ± 0.001 i | 14.047 ± 0.003 i | 8.226 ± 0.001 i |
Mi 5 | 11.84 ± 0.05 h | 1.778 ± 0.009 b | 7.148 ± 0.003 c | 13.127 ± 0.008 d | 7.496 ± 0.002 c |
Mi 6 | 9.76 ± 0.03 a | 2.337 ± 0.014 h | 7.764 ± 0.001 h | 13.835 ± 0.002 g | 8.099 ± 0.001 h |
Yangguang | 10.43 ± 0.04 c | 2.091 ± 0.013 e | 7.506 ± 0.002 f | 13.350 ± 0.005 e | 7.807 ± 0.001 e |
Yanshanhong | 11.29 ± 0.02 g | 1.737 ± 0.001 a | 6.954 ± 0.017 b | 12.983 ± 0.017 b | 7.329 ± 0.015 b |
Mean ± SD | 10.80 ± 0.63 | 2.007 ± 0.220 | 7.401 ± 0.358 | 13.348 ± 0.563 | 7.733 ± 0.361 |
Sig. | 0.993 | 0.485 | 0.744 | 0.564 | 0.819 |
Table 3.
Apparent amylose content, relative intensity, ordered degree, and lamellar structure parameters of starch.
Table 3.
Apparent amylose content, relative intensity, ordered degree, and lamellar structure parameters of starch.
Varieties | AAC (%) | RC (%) | OD | Lamellar Structure Parameters |
---|
PI (counts) | D (nm) |
---|
3113 | 26.1 ± 0.5 b,c | 20.0 ± 0.8 a,b | 0.61 ± 0.02 a | 143 ± 8 a,b | 9.46 ± 0.09 a |
Benlizi | 24.2 ± 0.7 a,b | 18.5 ± 0.5 a | 0.63 ± 0.02 a | 132 ± 6 a,b | 9.49 ± 0.00 a |
Dahongpao | 23.8 ± 1.1 a | 20.7 ± 0.8 a,b | 0.63 ± 0.02 a | 136 ± 16 a,b | 9.38 ± 0.01 a |
Erqingzao | 24.5 ± 0.9 a,b | 20.4 ± 0.5 a,b | 0.62 ± 0.02 a | 150 ± 3 b | 9.44 ± 0.04 a |
Heishanzhai 7 | 23.8 ± 0.9 a | 21.2 ± 0.9 b | 0.64 ± 0.02 a | 146 ± 7 a,b | 9.30 ± 0.01 a |
Mi 5 | 26.2 ± 1.1 b,c | 20.0 ± 1.4 a,b | 0.63 ± 0.01 a | 133 ± 8 a,b | 9.27 ± 0.03 a |
Mi 6 | 23.8 ± 0.9 a | 20.7 ± 0.4 a,b | 0.65 ± 0.02 a | 120 ± 4 a | 9.40 ± 0.01 a |
Yangguang | 24.6 ± 0.6 a,b | 21.2 ± 0.9 b | 0.64 ± 0.02 a | 130 ± 1 a,b | 9.33 ± 0.14 a |
Yanshanhong | 27.3 ± 0.5 c | 20.7 ± 0.6 a,b | 0.64 ± 0.02 a | 119 ± 3 a | 9.33 ± 0.01 a |
Mean ± SD | 24.9 ± 1.3 | 20.4 ± 0.8 | 0.63 ± 0.01 | 134 ± 11 | 9.38 ± 0.08 |
Sig. | 0.055 | 0.059 | 0.586 | 0.674 | 0.780 |
Table 4.
Thermal parameters of starch.
Table 4.
Thermal parameters of starch.
Varieties | To (°C) | Tp (°C) | Tc (°C) | ΔT (°C) | ΔH (J/g) |
---|
3113 | 62.7 ± 0.3 c | 68.1 ± 0.1 f | 74.5 ± 0.3 e | 11.8 ± 0.0 d,e | 13.1 ± 0.1 a |
Benlizi | 61.4 ± 0.1 b | 66.1 ± 0.1 c | 72.0 ± 0.1 c | 10.6 ± 0.0 c | 12.8 ± 0.2 a |
Dahongpao | 61.4 ± 0.2 b | 66.7 ± 0.2 d | 73.3 ± 0.0 d | 12.0 ± 0.2 e | 13.1 ± 0.1 a |
Erqingzao | 63.9 ± 0.1 d | 68.3 ± 0.1 f | 74.3 ± 0.0 e | 10.5 ± 0.1 b,c | 13.6 ± 0.1 a |
Heishanzhai 7 | 62.9 ± 0.1 c | 67.6 ± 0.1 e | 73.2 ± 0.2 d | 10.3 ± 0.1 a,b | 12.8 ± 0.2 a |
Mi 5 | 60.9 ± 0.0 b | 65.2 ± 0.0 b | 70.9 ± 0.0 a,b | 10.0 ± 0.0 a | 13.4 ± 0.2 a |
Mi 6 | 60.4 ± 0.0 a | 64.8 ± 0.1 a | 70.5 ± 0.1 a | 10.1 ± 0.1 a | 13.3 ± 0.4 a |
Yangguang | 61.3 ± 0.1 b | 66.4 ± 0.1 d | 72.9 ± 0.2 d | 11.6 ± 0.1 d | 12.8 ± 0.4 a |
Yanshanhong | 60.9 ± 0.1 b | 65.4 ± 0.1 b | 71.1 ± 0.1 b | 10.2 ± 0.0 a,b | 13.2 ± 0.1 a |
Mean ± SD | 61.8 ± 1.1 | 66.5 ± 1.3 | 72.5 ± 1.5 | 10.8 ± 0.8 | 13.1 ± 0.3 |
Sig. | 0.226 | 0.564 | 0.467 | 0.053 | 0.345 |
Table 5.
Pasting parameters of starch.
Table 5.
Pasting parameters of starch.
Varieties | PV (mPa s) | HV (mPa s) | BV (mPa s) | FV (mPa s) | SV (mPa s) |
---|
3113 | 5866 ± 49 c | 3104 ± 31 a,b | 2762 ± 18 f | 4745 ± 65 b,c | 1641 ± 37 c |
Benlizi | 6219 ± 38 d | 3487 ± 74 d | 2732 ± 48 e,f | 4954 ± 62 d | 1467 ± 41 d |
Dahongpao | 5722 ± 51 b | 3260 ± 40 b,c | 2462 ± 56 b,c | 4650 ± 35 b | 1390 ± 42 a,b |
Erqingzao | 5524 ± 21 a | 3319 ± 64 c | 2205 ± 84 a | 4942 ± 27 d | 1623 ± 50 c |
Heishanzhai 7 | 5527 ± 23 a | 3125 ± 59 a,b | 2402 ± 46 b | 4913 ± 35 d | 1788 ± 79 d |
Mi 5 | 6505 ± 41 e | 3616 ± 58 d | 2889 ± 51 g | 4942 ± 50 d | 1326 ± 27 a |
Mi 6 | 6192 ± 23 d | 3238 ± 23 b,c | 2954 ± 29 g | 4663 ± 32 b | 1425 ± 53 a,b |
Yangguang | 5609 ± 91 a | 3042 ± 98 a | 2567 ± 22 c,d | 4378 ± 68 a | 1336 ± 33 a |
Yanshanhong | 5860 ± 27 c | 3220 ± 67 b,c | 2640 ± 45 d,e | 4829 ± 34 c,d | 1609 ± 33 c |
Mean ± SD | 5892 ± 345 | 3268 ± 185 | 2624 ± 241 | 4780 ± 192 | 1512 ± 160 |
Sig. | 0.320 | 0.486 | 0.954 | 0.098 | 0.417 |
Table 6.
Digestion properties of starch.
Table 6.
Digestion properties of starch.
Varieties | Native Starch | Gelatinized Starch |
---|
RDS (%) | SDS (%) | RS (%) | RDS (%) | SDS (%) | RS (%) |
---|
3113 | 2.6 ± 0.3 a | 12.6 ± 0.0 c | 84.8 ± 0.3 a | 86.5 ± 1.3 b | 3.5 ± 0.8 c,d | 10.0 ± 0.5 b |
Benlizi | 3.7 ± 1.1 a | 11.3 ± 1.0 b,c | 85.0 ± 0.1 a | 84.8 ± 0.6 b | 3.1 ± 0.2 b,c,d | 12.1 ± 0.8 b,c |
Dahongpao | 3.0 ± 0.0 a | 12.5 ± 0.3 c | 84.4 ± 0.3 a | 80.4 ± 0.2 a | 2.4 ± 1.1 a,b,c,d | 17.3 ± 1.3 d |
Erqingzao | 3.3 ± 1.0 a | 10.0 ± 0.2 b | 86.7 ± 0.7 a | 80.7 ± 1.1 a | 1.9 ± 0.6 a,b,c | 17.4 ± 0.9 d |
Heishanzhai 7 | 3.5 ± 1.3 a | 5.7 ± 0.9 a | 90.7 ± 0.4 b | 79.6 ± 1.4 a | 3.0 ± 0.6 b,c,d | 17.3 ± 1.3 d |
Mi 5 | 3.4 ± 0.8 a | 11.7 ± 0.3 b,c | 84.9 ± 0.5 a | 84.8 ± 1.3 b | 1.3 ± 0.5 a | 13.9 ± 0.9 c |
Mi 6 | 2.9 ± 0.1 a | 11.9 ± 0.8 b,c | 85.2 ± 0.9 a | 86.2 ± 1.2 b | 1.5 ± 0.5 a,b | 12.3 ± 1.6 b,c |
Yangguang | 3.0 ± 0.0 a | 10.7 ± 0.6 b,c | 86.3 ± 0.6 a | 84.0 ± 1.4 b | 3.8 ± 0.5 d | 12.2 ± 1.5 b,c |
Yanshanhong | 2.9 ± 0.1 a | 12.7 ± 0.9 c | 84.4 ± 1.0 a | 89.5 ± 1.3 c | 3.4 ± 0.6 c,d | 7.1 ± 0.8 a |
Mean ± SD | 3.1 ± 0.4 | 11.0 ± 2.2 | 85.8 ± 2.0 | 84.1 ± 3.3 | 2.7 ± 0.9 | 13.3 ± 3.6 |
Sig. | 0.770 | 0.006 | 0.002 | 0.562 | 0.398 | 0.292 |