Comparative study of texture of normal and energy reduced sponge cakes.

The complete sucrose elimination and its replacement by microencapsulated aspartame (Nutra Sweet) and bulking agents (sorbitol, wheat starch and wheat germ) on the physical and textural sensory characteristics of two diabetic sponge cakes against a control sponge cake was studied. Mathematical and statistical methods were used and regression models worked out, describing the physical and textural characteristics of the three sponge cakes and their values were optimized. The effect on the porosity, springiness, volume and shrinkage of sponge takes was substantial and depended on the amount of the added ingredients. The diabetic sponge cake containing wheat germ showed the least physical and sensory deviations against the control sponge cake. The energy value of the diabetic sponge cakes against the control one was reduced with 25% for the ordinary sponge cake without sucrose and with 29% for sponge cake without sucrose containing wheat germ.

Nutrient medium optimization for rosmarinic acid production by Lavandula vera MM cell suspension.

The overall effect of NH(4)NO(3), KNO(3), and KH(2)PO(4) on the biosynthesis of rosmarinic acid and cell biomass by Lavandula vera MM cell suspension was studied by the method of the full factor experiment. Polynomial regression models were elaborated to give a quantitative description of the processes of biosynthesis of rosmarinic acid (Y(1)) and cell biomass (Y(2)) as a result of the variation of the concentration of NH(4)(+), 0.09 g/L < or = X(1) < or = 0. 23 g/L; NO(3)(-), 2.44 g/L < or = X(2) < or = 3.02 g/L; and KH(2)PO(4), 0. 170 < or = X(3) < or = 0.425 g/L. Optimization procedures according to the modified Simplex method allowed us to establish the optimal conditions for the biosynthesis of rosmarinic acid by Lavandula vera MM: X(1*) = 0.09 g/L; X(2*) = 3.02 g/L, and X(3*) = 0.170 g/L, where Y(1)max = 1786.74 mg/L (27 times higher compared with the cultivation in the standard Linsmayer-Skoog medium). As a result, modified ingredients of the Linsmayer-Skoog nutrient medium were applied for the cultivation of Lavandula vera MM to achieve a maximum yield of rosmarinic acid.

L-ascorbic acid in nonenzymatic reactions. I. Reaction with glycine.

The influence of the water content, molar ratio, time and temperature on the formation of nondialysable melanoidins produced by the interaction of L-ascorbic acid and glycine has been studied. The isolated polymers have been characterized by spectrum analysis and fractionated using gel chromatography. The rate constants of the reaction for temperatures of 90 degrees C, 100 degrees C and 110 degrees C have been calculated and are (0.84 +/- 0.29) x 10(-5) x s-1, (1.33 +/- 0.14) x 10(-5) x s-1 and (5.30 +/- 0.37) x 10(-5) x s-1, respectively. The activation energy of the reaction has been determined to be 106.07 +/- 32.47 kJ/mol.