Naratip Poonnakasem. EFFECT OF HYDROCOLLOIDS AND LIPIDS ON PHYSICOCHEMICAL PROPERTIES AND CONSUMER ACCEPTANCE OF SPONGE CAKE. Doctoral Degree(Food Technology). Chulalongkorn University. Office of Academic Resources. : Chulalongkorn University, 2014.
EFFECT OF HYDROCOLLOIDS AND LIPIDS ON PHYSICOCHEMICAL PROPERTIES AND CONSUMER ACCEPTANCE OF SPONGE CAKE
Abstract:
One of the important physicochemical property changes of sponge cake is staling which is presumed to be due to starch retrogradation and moisture migration. In this study, the effect of various hydrocolloids and lipids was determined. First, influence of hydrocolloids (hydroxy-propyl-methylcellulose, HPMC; xanthan gum, XG; alginate, AG) at 0.5 and 1.0% on textural kinetics of sponge cake during storage at 15, 25, 35 and 45 OC was studied. The firmness change of sponge cake at different storage temperatures followed a 1st-order kinetic reaction, where the activation energy (Ea) decreased in the following order: HPMC > AG > XG, which was in contrast to the firmness change rate constant (k). Addition of 0.5% HPMC gave the lowest k and highest Ea values, reflecting its better firmness retarding property. Moreover, effect of different lipids on physicochemical properties and consumer acceptance and emotion of sponge cake was evaluated. Healthy oils (extra virgin coconut oil, EVCO; extra virgin olive oil, EVOO; rice bran oil, RBO) vs. butter (control), were used at 20% in sponge cake. Overall liking and positive emotion scores of sponge cake made with EVCO were higher than others. Specific volume, expansion ratio, and moisture content of control, EVCO and EVOO were not significantly different, but higher than RBO sponge cake. Finally, influence of individual 0.5% HPMC or 20% EVCO and combination on physicochemical properties and microstructure of sponge cake during storage was studied. The use of HPMC and/or EVCO in sponge cake could retard the firmness rate in the following order: combination < EVCO < HPMC < control. The results were in line with X-ray diffraction data of crystallization degree and rate of crystallization, using Avrami equation. From correlation, it was found that firmness of sponge cake directly related to crystallization degree but inversely related to moisture content and spin-lattice relaxation time (T1) from nuclear magnetic resonance technique.