Extraction conditions for maximumvalues of yield, viscosity and minimum protein content of hydrocolloid extract from Lepidium sativum seed were investigated using response surface methodology. A Central Composite Face Design (CCFD) with four independent variables: temperature (25-85C); pH (3-0); extraction time (10-5 min) and water to seed ratio (10:1-0:1) was used to study the response variables (yield, viscosity and protein content). Data analysis showed that all the variables significantly (p < 0.05) affected the extraction yield and viscosity, whereas the effect of water to seed ratio on protein content was not significant (p > 0.05). Applying a desirability function method the optimum parameters were: extraction temperature 35
C, pH 10, water to seed ratio of 30:1 and an extraction time of 15 min. At this optimum point, apparent viscosity, yield and protein content were 0.2 Pa s, 6.46% and 0.57%, respectively. The experimental values were very close to the predicted values and were not statistically different (p > 0.05).

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