Sucrose reduction disrupts colligative equilibrium and molecular mobility in the freeze‐concentrated phase: Implications for recrystallisation evolution and structural stability of cream ice cream
Inês Carmo Luís, Cláudia Campos Pessoa, Diana Daccak, Madalena Dionísio, Fernando Lidon, Maria Manuela SilvaBackground/Context
Sucrose plays a critical role in ice cream stability by controlling colligative properties, phase equilibria and molecular mobility within the freeze‐concentrated matrix. Reducing sugar content is of growing industrial interest due to nutritional demands, but it poses significant technological challenges related to structural stability and shelf life.
Aim
This study investigated the effect of stepwise sucrose reduction (10–20%) on phase behaviour, thermal transitions and structural stability of cream ice cream during frozen storage.
Methods
Ice cream formulations with reduced sucrose levels were produced and analysed for total soluble solids, freezing behaviour, thermal properties and phase transitions. Key parameters included freezing point depression, crystallisation enthalpy, melting transitions and glass transition temperatures. Structural stability was inferred from thermal analyses and should therefore be interpreted as physicochemical rather than sensory stability.
Major Findings
Sucrose reduction decreased total soluble solids, weakening freezing point depression and increasing the fraction of freezable water. This shift altered phase equilibria, shifting the onset of ice crystallisation and modifying crystallisation enthalpy and melting transitions, indicating reorganisation of ice crystal structure. Changes in glass transition temperatures revealed alterations in the thermal response of the unfrozen phase. These changes were associated with sucrose reduction, although the underlying molecular mechanism could not be conclusively established from the present data. As a result, the matrix became structurally less stable. These results indicate increased molecular mobility within the freeze‐concentrated phase and a greater susceptibility of the frozen matrix to physicochemical destabilisation, greater susceptibility to ice crystal coarsening during storage.
Scientific/Industrial Implications
Sucrose reduction disrupts the thermodynamic and kinetic balance of frozen systems. While moderate sugar reduction is feasible, compensatory formulation and process strategies are required to maintain phase stability, control recrystallisation and ensure product quality and shelf life.