Algae. 1995; 10(2): 109-115.

Genetic Improvement of Eating Quality of Dried Sheets of Porphyra by Using the Recombinant Wild-Type in P. yezoensis (Bangiales, Rhodophyta)

Jong-Ahm Shin, Akio Miura

Department of Bioscience and Biotechnology, Faculty of Engineering, Aomori University

The recombinant wild-type (abbreviation: ZGRW) in pigmentation was bred by the cross between the green-type and the red-type pigmentation mutant of porphyra yezoensis. Growing tests of the gametothalli of the ZGRW were carried out for determining of characteristics pertaining to the ZGRW at eleven farming sites in autumn harvest in 1989 and spring harvest in 1990. Crispness indexes and free amino acids contents in dried sheets of Porphyra which are affected to eating quality were determined to compare the ZGRW with the growers' cultivars. Crispness indexes indicated as hardness values were 1.25-2.60 kg in the ZGRW compared to 1.73-3.16 kg in the growers' cultivars. The ZGRW showed better quality in crispness than growers' cultivars. Concerning free amino acids contents, alanine, aspartic acid, glutamic acid and taurine contents as well as total free amino acids contents in dried sheets of the ZGRW were always more abundant than those of the growers' cultivars. Alanine and glutamic acid contents which are especially concerned in taste substances in dried sheets of Porphyra were 523-2626 mg/100g and 593-1574 mg/100g in the ZGRW compared to 486-2526 mg/100g and 476-1473 mg/100g in the growers' cultivars, respectively. The ZGRW presented better quality in sweet taste than growers' cultivars.

Keywords : crispness index, crossbreeding, eating quality, free amino acids contents, genetic improvement, pigmentation mutant, Porphyra yezoensis, recombinant wild-type