State Diagram of Spray Dried Bovine Colostrum Powder

Figures & data

TABLE 1 Model parameters for BET and GAB equations

	Models
Model parameters	GAB	BET^a
M0 (g H2O/100 g dry solids)	6.189	5.142
C	16.445	24.935
K	0.845
MRE (%)	3.25	0.92
RMSE (%)	3.94	1.00
R^2	0.995	0.999
Residual plots	Random	Random

^aOnly experimental data with a_w < 0.50 were fitted to the BET model.

FIGURE 1 Water adsorption isotherm of SDBC powder at 25°C.

TABLE 2 Glass transition temperature of SDBC powder as a function of moisture content (when there is no formation ice)

aw	Xs (kg solids/kg samples)	Xw (kg H2O/kg samples)	Tgi (°C)	Tgm (°C)
0.0823	0.962	0.038	34.87 (0.95)^a	39.98 (1.39)
0.1130	0.958	0.042	34.73 (1.01)	38.59 (1.44)
0.4316	0.920	0.080	−1.18 (0.53)	1.26 (0.52)
0.5289	0.902	0.098	−11.76 (3.07)	−9.04 (2.42)
0.6500	0.883	0.117	−33.88 (1.87)	−28.68 (2.65)
0.7529	0.860	0.140	−45.20 (2.98)	−39.64 (4.24)

^aValues in the parentheses are standard deviations of three samples.

TABLE 3 Freezing point temperature and maximal-freeze-concentration conditions of bovine colostrum as a function of initial solid concentration

Xs (kg solids/kg samples)	(°C)	(°C)	(°C)	(°C)	(°C)	△Hm (kJ/kg)
0.198	2.13 (0.58)	−0.45 (0.15)	−3.26 (0.63)	−31.32 (1.11)^n	−50.48 (1.21)	257.81 (4.66)
0.279	0.59 (0.82)	−0.84 (0.07)	−4.26 (0.17)	−32.76 (0.94)	−48.95 (0.98)	221.63 (4.30)
0.399	−1.68 (0.56)	−3.15 (0.25)	−5.65 (1.08)	−31.70 (0.85)	−50.39 (0.85)	167.48 (6.35)
0.501	−2.68 (0.31)	−3.75 (0.33)	−6.21 (0.25)	−32.24 (0.79)	−50.38 (1.02)	109.48 (13.18)
0.591	−3.55 (1.1)	−6.49 (2.81)	−14.94 (1.13)	−32.78 (1.18)	−48.90 (0.56)	82.84 (5.84)
0.660	−5.77 (0.42)	−8.95 (2.12)	−15.38 (0.58)	−32.43 (0.16)	−51.76 (0.85)	63.29 (0.18)

ⁿValues in the parentheses are standard deviations of three samples.

^aPeak of ice melting endotherm.

^bMaximum slope of ice melting endotherm.

^cOnset of ice melting endotherm.

FIGURE 2 A typical DSC thermogram of bovine colostrum containing freezable water (0.501 kg solids/kg samples) for 30 min annealing (, , and are the peak, maximum slope, and start of ice melting endotherm, and is the end point of freezing for maximal-freeze-concentration condition).

FIGURE 3 Enthalpy change of ice melting as a function of water content.

FIGURE 4 State diagram of spray dried bovine colostrum.

FIGURE 5 Relationships between glass transition temperature, water activity, and water content of SDBC powder.