Effects provided by sugar substitutes upon the quality indicators of model systems of sweetened condensed milk in storage

Abstract

Sweetened condensed milk (SCM) is a product widely used by both consumers and other food production branches. However, it contains a lot of sucrose. This study aimed to examine the effects provided by sugar substitutes—trehalose, isomaltulose, and polydextrose—upon the SCM sensory profile and valuable quality indicators, such as water activity (Aw), viscosity, acidity, crystal size, and Maillard reaction potential (browning index, color change, loss of free AA). The study was performed by making model systems of SCM (MSCM) using the method of reconstitution of powdered ingredients. All the presented carbohydrate compositions in MSCM provided Aw value typical of intermediate-moisture food, which contributes to the long-term shelf life of the product. However, only 2 MSCM showed stability of Aw within a 14-d storage period: a composition of isomaltulose and trehalose (each at 22.55%), and a composition of trehalose (28.19%), sucrose (5.64%), polydextrose (5.64%), and isomaltulose (5.64%). Trehalose and polydextrose in MSCM with monocarbohydrate added fraction demonstrated their high structure-forming ability, expressed in high values of dynamic viscosity (>30 Pa·s). The MSCM containing a predominant amount of trehalose in the carbohydrate compositions (≥50%) showed lower average crystal size (<16 μm) compared with MSCM with di- and tetra-carbohydrate added fractions with predominant amounts of isomaltulose or polydextrose. Isomaltulose and polydextrose added to MSCM led to pronounced browning, whereas trehalose and sucrose reduced this effect in MSCM with di- and tetra-carbohydrate added fractions. Polydextrose added at 22.55% to carbohydrate fraction of MSCM caused bitterness, whereas the addition at 5.64% did not affect the taste. Based on the results of all the research conducted, the optimal carbohydrate compositions to produce SCM with fewer calories, lower sucrose content, and stable, adequate values of processing and sensory properties were trehalose (22.55%) with isomaltulose (22.55%), and trehalose (28.19%) with sucrose (5.64%), polydextrose (5.64%), and isomaltulose (5.64%).