NUTRITIONAL ANALYSIS OF PUGET SOUND BULL KELP (NEREOCYSTIS-LUETKEANA)

Samples of N. luetkeana, an edible brown algae, were collected from Puget Sound. The freeze-dried samples were analyzed for proximate and elemental composition and evaluated for protein quality by amino acid analysis and using Tetrahymena pyriformis W. The freeze-dried frond, stipe and bulb of the algae showed similar composition; the frond had a protein content twice that found in the bulb and stipe and 5 times less crude fiber than the stipe. The proximate analysis of the frond was 15.3% protein, 1.3% crude fiber, 42.7% ash, 1.9% crude fat and 38.8% carbohydrate (by difference). Based on neutron activation analysis, Nereocystis contained appreciable quantities of Na, K, Ca and Fe. The algae protein appeared to be of high quality based on growth of T. pyriformis W. on a pepsin digest of the algae and on the amino acid profile and in vitro digestibility of the intact algae. [The nutritional quality with respect to human consumption is discussed.].