A new dietary low-fat custard formulation made by waxy corn starch and xylitol: Rheological, sensory and in vitro digestibility investigation

Custard is a dairy starch-based dessert, in which presence of milk increases its nutritional value and sensitivity to freezing, pH, and storage. Producing a custard with less phase separation during storage and improving its functionality is challenging. The present study has investigated the effect of starch type (native corn starch and waxy corn starch), fat content (2.67% & 0.1%) and sucrose-xylitol ratio (1:0, 1:1, 0:1) on rheological, textural, enzyme digestibility and sensory properties of custard desserts. The back extrusion test showed a significant increase in consistency (40.60 mJ) by using xylitol and decreasing fat content compared to the control sample (2.16 mJ). Also, applying waxy corn starch diminished hardness (1.66 N) compared to the control (13.55 N), which was accompanied by a decrease of syneresis after five days of storage from 10.29% to 0.02% and improvement of sensory properties of creaminess, smoothness and taste intensity. Accordingly, low-fat custard formulation containing waxy corn starch and xylitol indicated high creaming stability (98.08%), adhesiveness (9.45 mJ), viscosity at a constant shear rate of 50 s−1 (3.58 Pa s), and water holding capacity after five days of storage at 4 °C (99.99%) and thickness (9.53). Also, xylitol reduced custards' glucose release after amylase objection.