Inhibitory effects of additives and heat treatment on the crystallization of freeze-dried sugar

Effects of Mono‐, Di‐, and Tri‐Saccharides on the Stability and Crystallization of Amorphous Sucrose

“…These data fit with the concepts that: (1) additives with enough structural similarity to sucrose to produce a good overlap in crystal structure overlays (Figure , with glucose overlapping better than fructose), and (2) additional structural units that have the potential to alter further crystal growth (as seen in the different morphologies present in Figure ) tend to increase the T cry and delay sucrose crystallization in controlled temperature and RH environments. The data provide further evidence in support of previous reports relating stabilization of amorphous sucrose to the T cry of saccharide additives (Kinugawa et al., ) and attachment of additives to sucrose crystal growth faces (Leinen & Labuza, ). As shown in Table , some saccharides have the potential to delay sucrose crystallization even beyond the stability imparted by raffinose, and with potentially fewer side effects related to the indigestibility of raffinose.…”

“…At 0% RH, the lyophiles containing lactose and trehalose had the highest T cry s (131 °C), although the sucrose control and sucrose:glucose lyophiles had the lowest T cry s (112 to 114 °C; Table ). An earlier study reported that the addition of 3% to 5% w/w mono‐ or di‐saccharide to sucrose increased the T cry which correlated to an increased stability of amorphous sucrose (Kinugawa et al., ). Although most saccharides increased the T cry (Table ) and delayed the onset of sucrose crystallization (Table ), the magnitude of the increase in T cry of samples stored at 0% RH did not correlate to the delay in sucrose crystallization found in the desiccator studies.…”

“…Sucrose crystallization during storage has been widely studied and found to be sensitive to temperature and relative humidity (RH; Makower & Dye, ; Mathlouthi, ; Wang and Truong, 2017). Different approaches have been used to create amorphous sucrose (including spray drying, freeze drying, and vitrification), and the most common analyses applied to document amorphous sucrose stability include thermal analyses using differential scanning calorimetry to determine the glass transition temperature ( T g ), crystallization temperature ( T cry ), and crystallization induction times using isothermal and non‐isothermal conditions (Carstensen & Van Scoik, ; Kinugawa et al., ; Levenson & Hartel, ; Ohtake, Schebor, Palecek, & de Pablo, ; Saleki‐Gerhardt & Zografi, ; Shamblin, Huang, & Zografi, ; Shamblin, Taylor, & Zografi, ; te Booy, de Ruiter, & de Meere, ; Thorat, Forny, Meunier, Taylor, & Mauer, ). Adding a compatible ingredient to sucrose, such as a polymer, salt, or other sugar, has the potential to delay sucrose crystallization (Carstensen & Van Scoik, ; Kinugawa et al., ; Levenson & Hartel, ; Ohtake et al., ; Saleki‐Gerhardt & Zografi, ; Shamblin et al., , ; te Booy et al., ; Thorat et al., ).…”

“…Different approaches have been used to create amorphous sucrose (including spray drying, freeze drying, and vitrification), and the most common analyses applied to document amorphous sucrose stability include thermal analyses using differential scanning calorimetry to determine the glass transition temperature ( T g ), crystallization temperature ( T cry ), and crystallization induction times using isothermal and non‐isothermal conditions (Carstensen & Van Scoik, ; Kinugawa et al., ; Levenson & Hartel, ; Ohtake, Schebor, Palecek, & de Pablo, ; Saleki‐Gerhardt & Zografi, ; Shamblin, Huang, & Zografi, ; Shamblin, Taylor, & Zografi, ; te Booy, de Ruiter, & de Meere, ; Thorat, Forny, Meunier, Taylor, & Mauer, ). Adding a compatible ingredient to sucrose, such as a polymer, salt, or other sugar, has the potential to delay sucrose crystallization (Carstensen & Van Scoik, ; Kinugawa et al., ; Levenson & Hartel, ; Ohtake et al., ; Saleki‐Gerhardt & Zografi, ; Shamblin et al., , ; te Booy et al., ; Thorat et al., ). Crystallization processes proceed via nucleation followed by crystal growth, and most additives that were effective at delaying sucrose crystallization were found to delay sucrose crystal growth by: increasing T g and viscosity (Roos & Karel, ; Van Hook, ), altering the behavior of water (e.g., ions with higher hydration numbers delayed sucrose crystallization more than those with lower hydration numbers) (Thorat et al., ), and/or interfering with sucrose crystal growth due to structural dissimilarities (Leinen & Labuza, ; Saleki‐Gerhardt & Zografi, ).…”

“…The addition of fructose and glucose to supersaturated aqueous solutions of sucrose inhibited sucrose crystallization, and increasing the concentration of added monosaccharide decreased the rate of sucrose crystallization (Laos, Kirs, Kikkas, & Paalme, ). The addition of 3% to 5% by weight of glucose, fructose, trehalose, lactose, or maltose to sucrose was found to increase the induction time for sucrose crystal nucleation in freeze‐dried matrices (Kinugawa et al., ). In hard candies, melting sucrose and fructose together led to the formation of more stable glasses than sucrose melted alone when samples were cooled and exposed to 11% to 43% RH for 24 hr (Roos & Karel, ).…”