MINERAL-ALGAL-BOTANICAL COMPLEX 33 15% 12% 9% 6% 3% O% 8 12 Time (h) •complex ,•:• co ntro I Figure 2. Skin-moisturizing effects of two cream preparations. Percentage of relative improvement after eight and twelve hours of skin treatment, observed by corneometeric analysis of skin moisture. Mean of 20 subjects _+ SEM. Table IV Mineral Biosorption to Dunaliella salina CCAP 19/31 Biomass: Typical Values (measured in dry, acid-soluble biomass) Calcium (mg/g D.W. algae [mmol/g D.W. algae]) Magnesium (mg/g D.W. algae [mmol/g D.W. algae]) Potassium (mg/g D.W. algae [mmol/g D.W. algae]) Before biosorption 2.5 (0.06) 6.1 (0.25) 6.7 (0.1) After biosorption 30 (0.75) 12 (0.5) 0.28 (4.3 ß 10 -3) %Relative biosorption 1100% 100% -95% THE INFLUENCE OF VARIOUS PARAMETERS ON ELEMENT DESORPTION FROM DUNALIELLA SALINA The conditions for mineral desorption from saturated Dunaliella salina biomass were evaluated in order to determine and to predict the release ratio of minerals from the biomass to human skin. The influence of the pH of the solution (1.5-5), brine tem- perature (10ø-40øC), and exposure time (5-30 minutes) were simultaneously assessed. The relative desorption of calcium and magnesium were subjected to a linear analysis, and a model, predicting the desorption of minerals from the Dunaliella biomass, was suggested. Since the potassium concentratoin in the saturated biomass was very low, its measured values were excluded. The pH value was found to be the most influential parameter for both calcium and magnesium: as the pH decreased, desorption from the biomass correspondingly increased (p 0.01).

34 JOURNAL OF COSMETIC SCIENCE .•1.0 E '• 0.8 E - ._ o 0.2 E E 0.0 Blank 10 33 40 Temperature (C) -0.16 :0.14 -0.12 -0.10 -0.08 .o.o6 .0.02 0.00 IT•I calcium [] magnesiu• potassium I 0.8 0.6 0.4 0.2 0.0 Blank 4 4.5 5 5.5 5.8 pH .0.16 0.14 0.12 :O. lO :0.08 1o.o6 '-0.04 , -0.02 D.00 II•calcium :[] magnesiurr•potassium I e 1.2 •1.o E .E 0.8 E E o.4 ._ 0.2 0 E E o.o i i i i 0 5 10 15 30 Time (minutes) .0.16 '0.14 '0.12 .0.10 ,0.08 .0.06 ,0.04 ,0.02 0.00 ][1I• calcium i[] magnesium I potassium ] Figure 3. The effect of pH value, temperature, and exposure time to Dead Sea concentrated brine (Mineral Skin Osmoter TM) on the biosorption of elements to Dunaliella salina algal biomass. Blank values relate to non-treated algae.