Utilization of Algae as a Protein Source for Humans

Safety evaluation of a high-lipid algal biomass from Chlorella protothecoides

Chlorella are traditionally freshwater green algae that have been evaluated for dietary purposes because of their nutritional value. This study investigates the safety of Chlorella protothecoides in a 28-day study. Sprague-Dawley rats were administered 0 (control), 2.5, 5.0, or 10% of their diet for 28days using an FDA Redbook protocol. The average daily dietary intake of algal biomass was determined to be 0, 1794, 3667, and 7557 mg/kg body weight for males and 0, 1867, 3918, and 8068 mg/kg body weight for females. Hematological and biochemical analyses were conducted, and upon completion, gross and microscopic evaluations were performed. No signs of toxicity were observed. Although statistically significant alterations were noted in several parameters among males and females, these changes were deemed to be of no toxicological significance due to the lack of dose-response relationships, the fact that they occurred in only one sex, and the lack of any supporting gross or microscopic alterations. The no-observed-adverse-effect level for the algal biomass under the conditions of this study was considered to be 10% in the diet, the highest dose tested.

Isolation of Pancreatic Lipase Activity-inhibitory Component of Spirulina Platensis and It Reduce Postprandial Triacylglycerolemia

In the process of investigating the hypolipidemic effects of Spirulina platensis, we found that the aqueous extract of S. platensis may inhibit the intestinal absorption of dietary fat by inhibiting pancreatic lipase activity. The aqueous extract of S. platensis (500 m/kg) reduced the elevation of rat plasma triacylglycerol levels after oral administration of the lipid emulsion 2 h after administration. To clarify the hypolipidemic effects of S. platensis, the active component was isolated and designated 1'-O-(palmitonyl)-2'-O-(caprylonyl) glyceryl-beta-alpha-D-galactopyranoside (glycolipid H-b2). Glycolipid H-b2 was found to inhibit pancreatic lipase activity in a dose-dependent manner. The fractions containing glycolipid H-b2 (250 mg/kg) reduced the elevation of rat plasma triacylglycerol levels after oral administration of the lipid emulsion 2 h after administration. Furthermore, we examined the effects of phycocyanin isolated from S. platensis on pancreatic lipase activity. Phycocyanin inhibited the pancreatic lipase activity in a dose-dependent manner. These results suggest that the inhibitory effects of S. platensis on postprandial triacylglycerolemia may be due in part to the inhibition of pancreatic lipase activity by glycolipid H-b2 and phycocyanin.

The possible utilization of the 1-amino-1-deoxy-2-ketose compounds between amino acids and carbohydrates as foodstuff integrators

The behavior of the primary products (1-amino-1-deoxy-2-ketose-derivatives) from amino acids and monosaccharides in the Maillard reaction to the action of pepsin, trypsin, chymostrypsin and of heating has been investigated, in order to test the possibility of their utilization as foodstuff integrators. The behavior is very different from the corresponding behavior of the original amino acids.