A Tentative Explanation for the Substantial Rise of the Gelatinization Temperature of Starch by Adding Salt and Hydroxide

Figures & data

Table 1 Thermal analyses of CCS-water and CCS-water-salt systems.

Samples	To ^a (°C)	Tp ^b (°C)	Te ^c (°C)	ΔTgr ^d (°C)	ΔTgel ^e (°C)	ΔH ^f (J/g)
CCS	60.36 ^g (±0.47)	66.33 (±0.51)	73.22 (±0.31)	12.86 (±0.56)	–	18.85 (±0.64)
CCS + LiCl (2m)	71.3 (±0.27)	78.33 (±0.42)	85.45 (±0.37)	14.15 (±0.46)	10.94 (±0.54)	20.1 (±0.7)
CCS + LiCl (4m)	66.97 (±0.51)	73.67 (±0.45)	81.44 (±0.43)	14.47 (±0.67)	6.61 (±0.58)	20.58(±0.61)
CCS + NaCl (2m)	70.09 (±0.55)	76 (±0.41)	83.12 (±0.37)	13.03 (±0.66)	9.73 (±0.75)	20.63 (±0.55)
CCS + NaCl (4m)	67.06 (±0.5)	73.83 (±0.37)	81.28 (±0.51)	14.22 (±0.71)	6.70 (±0.74)	19.42 (±0.51)
CCS + KCl (2m)	68.94 (±0.45)	73.83 (±0.43)	81.36 (±0.39)	12.42 (±0.65)	8.58 (±0.67)	19.55 (±0.55)
CCS + KCl (4m)	65.64 (±0.49)	71.7 (±0.5)	79.8 (±0.43)	14.16 (±0.65)	5.28 (±0.67)	19.28 (±0.47)
^a To = onset temperature; ^bT^p = peak temperature; ^cTe = end temperature; ^dΔTgr = gelatinization range; ^eΔTgel = rise of gelatinization compared with CCS-Water system; ^fΔH = gelatinization enthalpy; ^gMean of two observations.

Table 2 Thermal analyses of CCS-water-salt-NaOH systems.

Samples	To ^a (°C)	Tp ^b (°C)	Te ^c (°C)	ΔTgr ^d (°C)	ΔTgel ^e (°C)	ΔH ^f (J/g)
LiCl (2m) + NaOH (0.25m)	70.86 ^g (±0.39)	77.5 (±0.41)	84.77 (±0.47)	13.91 (±0.61)	10.50 (±0.61)	15.52 (±0.6)
LiCl (2m) + NaOH (0.5m)	62.1 (±0.41)	70.83 (±0.39)	80.26 (±0.52)	18.16 (±0.66)	1.74 (±0.62)	9.93 (±0.5)
LiCl (4m) + NaOH (0.25m)	69.7 (±0.47)	76.33 (±0.42)	82.98 (±0.51)	13.28 (±0.69)	9.34 (±0.66)	13.39 (±0.47)
LiCl (4m) + NaOH (0.5m)	66.45 (±0.51)	73.83 (±0.41)	81.71 (±0.52)	15.26 (±0.73)	6.09 (±0.69)	10.9 (±0.65)
NaCl (2m) + NaOH (0.25m)	73.45 (±0.37)	80.17 (±0.5)	87.51 (±0.41)	14.06 (±0.55)	13.09 (±0.60)	13.89 (±0.61)
NaCl (2m) + NaOH (0.5m)	70.81 (±0.31)	77.83 (±0.46)	88.68 (±0.4)	17.87 (±0.51)	10.45 (±0.56)	11.16 (±0.71)
NaCl (4m) + NaOH (0.25m)	76.41 (±0.56)	83.67 (±0.46)	92.58 (±0.46)	16.17 (±0.72)	16.05 (±0.73)	12.93 (±0.69)
NaCl (4m) + NaOH (0.5m)	81.65 (±0.55)	89 (±0.55)	97.05 (±0.49)	15.40 (±0.74)	21.29 (±0.72)	11.7 (±0.52)
KCl (2m) + NaOH (0.25m)	85.11 (±0.57)	93.83 (±0.53)	108.66 (±0.52)	23.55 (±0.77)	24.75 (±0.74)	16.44 (±0.27)
KCl (2m) + NaOH (0.5m)	92.82 (±0.5)	99.17 (±0.47)	107.25 (±0.53)	14.43 (±0.73)	32.46 (±0.69)	14.17 (±0.39)
KCl (4m) + NaOH (0.25m)	88.4 (±0.48)	100.7 (±0.47)	113.83 (±0.41)	25.43 (±0.63)	28.04 (±0.67)	14.35 (±0.44)
KCl (4m) + NaOH (0.5m)	108.4 (±0.5)	114.33 (±0.45)	118.33 (±0.41)	9.93 (±0.65)	48.04 (±0.69)	8.23 (±0.51)
^a To = onset temperature; ^bTp = peak temperature; ^cTe = end temperature; ^dΔTgr = gelatinization range; ^eΔTgel = rise of gelatinization compared with CCS-Water system; ^fΔH = gelatinization enthalpy; ^g Mean of two observations.

Figure 1 Differential scanning calorimetry thermograms of CCS, CCS-water-salt, and CCS-water-salt-NaOH. 4(a) Systems with 2 molal salt concentration. (b) Systems with 4 molal salt concentration.