TY - JOUR
T1 - Mutarotation and solubility of lactose as affected by carrageenans
AU - Sánchez-García, Yanira I.
AU - Gutiérrez-Méndez, Néstor
AU - Salmerón, Iván
AU - Ramos-Sánchez, Víctor H.
AU - Leal-Ramos, Martha Y.
AU - Sepúlveda, David R.
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/4
Y1 - 2021/4
N2 - It has been reported that polysaccharides like carrageenan can change the crystallization of lactose. However, it is still unclear whether changes in lactose mutarotation, solubility, and super-solubility are involved in carrageenans' effect on lactose crystallization. It has been established that the conversion of α- to β-lactose forms (mutarotation) in an aqueous solution has a significant impact on lactose crystallization. Similarly, lactose solubility changes lead to changes in the metastable zone (MZ), a region between the solubility and super-solubility of lactose. The width of this MZ determines the temperature drop necessary to induce lactose nucleation. This work aimed to study the effect of carrageenans on lactose mutarotation and solubility. For this purpose, lactose solutions were added with ι and κ- carrageenan at two concentrations: 50 and 100 mg L−1. Optical rotation measurements estimated the proportion of β/α isomers in lactose solutions. Besides, solubility and super- solubility was determined to build the MZ. The presence of carrageenans changed both the time to reach the mutarotation balance and the proportion of β/α isomers at mutarotation equilibrium. Carrageenans decreased the solubility of lactose in a range of temperatures between 10 and 60 °C and reduced the metastable zone width (MZW).
AB - It has been reported that polysaccharides like carrageenan can change the crystallization of lactose. However, it is still unclear whether changes in lactose mutarotation, solubility, and super-solubility are involved in carrageenans' effect on lactose crystallization. It has been established that the conversion of α- to β-lactose forms (mutarotation) in an aqueous solution has a significant impact on lactose crystallization. Similarly, lactose solubility changes lead to changes in the metastable zone (MZ), a region between the solubility and super-solubility of lactose. The width of this MZ determines the temperature drop necessary to induce lactose nucleation. This work aimed to study the effect of carrageenans on lactose mutarotation and solubility. For this purpose, lactose solutions were added with ι and κ- carrageenan at two concentrations: 50 and 100 mg L−1. Optical rotation measurements estimated the proportion of β/α isomers in lactose solutions. Besides, solubility and super- solubility was determined to build the MZ. The presence of carrageenans changed both the time to reach the mutarotation balance and the proportion of β/α isomers at mutarotation equilibrium. Carrageenans decreased the solubility of lactose in a range of temperatures between 10 and 60 °C and reduced the metastable zone width (MZW).
KW - Carrageenan
KW - Lactose
KW - Metastable zone
KW - Mutarotation
KW - Polarimetry
KW - Solubility
KW - Supersaturation
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U2 - 10.1016/j.foodres.2021.110204
DO - 10.1016/j.foodres.2021.110204
M3 - Article
C2 - 33773679
AN - SCOPUS:85101085371
SN - 0963-9969
VL - 142
JO - Food Research International
JF - Food Research International
M1 - 110204
ER -