The farmed Eucheuma species (Gigartinales, Rhodophyta) in Danajon Reef, Philippines : carrageenan properties

Six cultured `strains' of Eucheuma denticulatum and E. alvarezii, from which stocks can be selected for the development of a Eucheuma `seedling bank', were tested for their carrageenan quality from June to November 1988 . Percent yield of all the varieties taken together was apparently higher in June, becoming lower in November (regression, r -0.785, probability,p 5 0.001). Stepwise regression analysis was done to determine the existence of any relationship between any of the following parameters : gel strength, viscosity, sulfate content, month of sampling, and yield, whether taken individually or in combination . Results show variations of the yield with the month of sampling . ANOVA was performed to test whether there are differences in sulfate levels, gel strength, and viscosity between the Eucheuma alvarezii morphotypes. There was no significant difference between the green and the brown types.