Starch Retrogradation in Rice Cake: Influences of Sucrose Stearate and Glycerol

Retrogradation properties and kinetics of rice cakes with the addition of glycerol (GLY) and sucrose fatty acid ester (SE) were investigated. In hardness, both rice cakes with glycerol (RGLY) and rice cakes with sucrose fatty acid ester (RSE) showed lower initial hardening compared with the control for up to 5 days. X-ray diffraction (XRD) pattern of RSE showed a B+V-type pattern, and the relative crystallinity showed that GLY and SE lowered the initial and final crystallization of rice cake. Both GLY and SE affected the retrogradation enthalpy, glass transition temperature, and ice melting enthalpy in differential scanning calorimeter (DSC). However, 1H NMR relaxation time (T2) of rice cake decreased regardless of additives. From these results, the addition of glycerol and sucrose stearate inhibits the retrogradation process of rice cakes, which will solve industrial problems. Applying the Avrami equation for retrogradation kinetics of rice cake was suitable in XRD and DSC with high coefficient of determination (0.9 < R2). Meanwhile, the other retrogradation index improved the R2 when the exponential rise to maximum equation was used. This suggests that there is an alternative of Avrami equation to predict the retrogradation.

Application of Octenyl Succinate Starch Ester (SSOS) in Peanut Beverage

In this paper, the effects of octenyl succinate starch ester, carrageenan, monoglyceride and sucr ose fatty acid ester compound emulsifier on the sensory evaluation of floating layer thickness, sedimentati on rate and precipitation were analyzed. the optimal scheme for making peanut protein beverage with octe nyl succinate starch ester was 0.09% xanthan gum,0.06% carrageenan,0.15% sucrose fatty acid ester and 0.15%monoglyceride. It is proved that the application of octenyl amber acid starch ester as stabilizer in peanut protein beverage is feasible.

Lipase-Catalyzed Synthesis of Sucrose Fatty Acid Ester and the Mechanism of Ultrasonic Promoting Esterification Reaction in Non-Aqueous Media

The preparation of sucrose fatty acid ester (SFAE) by lipase-catalyzing reaction usingCandida antarcticalipase B (CalB) and its immobilized form Novozym 435 was reported in this work. The preparation was characterized in non-aqueous media with and without ultrasound irradiation treatment. A conversion rate of SFAE up to 49.60% was achieved using Novozym 435 under the optimal conditions (45.4°C; mole ratio of methyl oleate to sucrose = 6.0:1; 4.0 mL acetone; 4.0 mg/mL Novozym 435; and 24.6 h of reaction). Under optimal ultrasound conditions (50 kHz, 0.15 W/cm2, 166.55 min), reaction time decreased by 75% approximately, compared with the control without ultrasonic irradiation, but the ultrasound irradiation treatment did not affect the SFAE yield catalyzed by Novozym 435. In the CalB-catalyzed preparation of SFAE under the same optimal reaction conditions, ultrasonic irradiation enhanced the activity of CalB during early time points and inhibited its activity after a long period of treatment. Moreover, CalB was further examined using Far-UV circular dichroism (CD) spectroscopy and scanning electron microscopy (SEM) to study the conformation and micro-morphology of CalB structural variations in various ultrasound irradiation treatments. CD results indicated that α-helical regions were increased and random coil regions remained at a similar level of proportion. SEM images showed small holes appeared on the surface of irradiated CalB. Therefore, we conclude that proper ultrasound irradiation could change the secondary structure and the surface morphology of the CalB in molecular level, and could accelerate the esterification reaction process.