Effects of Co-Formulation of Amorphous Maltodextrin and Deliquescent Sodium Ascorbate on Moisture Sorption and Stability

Figures & data

Figure 1 Adsorption isotherms for M100 and M180 maltodextrins, sodium ascorbate, and blends of M100 and M180 with ascorbate at 22°C. Data points are connected by trend lines. Formulations are shown by:

M100

M180

Ascorbate

M100+ascorbate

M180+ascorbate.

Figure 2 Glass transition temperature (T_g) for maltodextrins equilibrated at increasing RH analyzed by DSC. T_g values were determined from the onset temperature. Data points are connected by trend lines. Selected maltodextrins are shown by:

M100

M180.

Figure 3 Difference in percent moisture sorption between experimental and predicted moisture sorption isotherms of M100 maltodextrin+ascorbate and M180 maltodextrin+ascorbate blends exposed to 0–95% RH and 25C. Predicted isotherms were calculated from the experimental moisture sorption isotherms of the individual ingredients. The predicted moisture sorption isotherms of the mixtures were then compared to those obtained experimentally for the same mixture and the difference was plotted against RH. Data points are connected by trend lines. Different formulations are shown by:

M100+ascorbate

M180+ascorbate.

Figure 4 Sodium ascorbate stability at different storage RHs, formulated with and without maltodextrin (M100). A) 98% RH; B) 85% RH; C) 75% RH; D) 43% RH. Data points are connected by trend lines. Individual ascorbate and M100 maltodextrin mixtures are shown by:

Sodium ascorbate

M100+ascorbate.

Table 1 Endpoint vitamin C degradation after 4 weeks of storage at select RHs for individual sodium ascorbate and binary mixtures of sodium ascorbate and M100 or M180 maltodextrin. Results are reported as % degradation with standard deviations, and different letters indicate significant differences. ^a

	Storage RH (%)
Formulation	98	85	75	43
Ascorbate	77.8 ± 2.4 ^a	51.0 ± 3.0 ^b	4.4 ± 3.9 ^e	1.5 ± 2.0 ^e
M100 + ascorbate	34.3 ± 6.3 ^c	21.9 ± 1.9 ^d		5.1 ± 3.5 ^e
M180 + ascorbate			8.4 ± 2.1 ^e
^aSamples with different letters had significantly different degradation of sodium ascorbate compared to all other formulations.

Figure 5 Weight change (%) versus % sodium ascorbate remaining for individual sodium ascorbate and its blend with M100 maltodextrin stored at 98% RH and 25°C up to 4 weeks. Data points are connected by trend lines. Trends for ascorbate and its blend are show by:

Ascorbate

M100+ascorbate.

Figure 6 Weight change (%) over time for sodium ascorbate and its blends with M100 and M180 maltdoextrin stored up to 4 weeks at 22°C and select RH conditions. A) Weight change (%) over time for individual sodium ascorbate samples during controlled RH storage. Data points are connected by trend lines. Ascorbate samples at each RH are shown by:

98

85

75

43 B) Weight change (%) over time for binary mixtures of sodium ascorbate and maltodextrins during controlled RH storage. Data points are connected by trend lines. Mixture weight change at each RH is shown by:

98M100:A

85M100:A

75M180:A

43M100:A.

Table 2 Sodium ascorbate degradation after storage for 2 weeks in premixed ascorbate:maltodextrin samples and ascorbate blended with pre-equilibrated maltodextrin samples. Results are reported as % degradation with standard deviations, and different letters indicate significant differences. ^a

			Storage RH (%)
Formulation	Preparation ^b	Time (weeks)	98	75	43
M100 + ascorbate	Premixed	2	14.3 ± 1.9 ^b		7.8 ± 4.9 ^bcde
M180 + ascorbate	Premixed	2		9.4 ± 2.3 ^bcd
M100 + ascorbate	Pre-equilibrated	2	15.6 ± 3.2 ^b		4.0 ± 1.5 ^cde
M180 + ascorbate	Pre-equilibrated	2	9.6 ± 1.5 ^bde	10.1 ± 1.1 ^bc	1.7 ± 1.7 ^de
^aSamples with different letters had significantly different degradation of sodium ascorbate compared to all other formulations.
^bPreparation methods are identified as: “premixed” describing ascorbate:maltodextrin blends that were stored in RH chambers then analyzed, and “pre-equilibrated” describing maltodextrin samples that were pre-equilibrated at the identified RH, then blended with ascorbate, sealed, and stored for the identified time prior to analysis.