Abstract:

In order to understand the relationships of gel strength (GS) of agar from Gracilaria sjoestedtii Kylin with cold alkaline treatment conditions such as temperature (T), alkali concentration (M) and treatment time (t), 12 uniform design experiments were done, and the experimental results were fitted into the following equation: GS = 27.72 × T + 19.69 × M + 2.75 × t －488.62 (P ＜ 0.0001) using multiple linear regression, which revealed that the three variables made contributions to the dependant variable in the decreasing order of T ＞ M ＞ t. No significant difference was observed between the experimental and the predicted values of GS (P＞0.05) in 7 validation experiments. This demonstrated the excellent reliability of the regression model in predicting GS. This investigation can lay a scientific basis for the optimization of cold alkaline treatment, the improvement of quality and the reduction of production cost of agar from Gracilaria sjoestedtii Kylin.

Key words: Gracilaria sjoestedtii Kylin, agar, gel strength