Safety evaluation of a high lipid Whole Algalin Flour (WAF) from Chlorella protothecoides

Microalgae such as Chlorella spp. have a long history of use in human food. A high lipid Whole Algalin Flour (WAF) composed of dried milled Chlorella protothecoides was evaluated for subchronic toxicity and genotoxic potential. Likelihood of food allergy potential was also evaluated by human repeat-insult patch test. In the subchronic study, rats were fed dietary levels of 25,000, 50,000 or 100,000ppm WAF in feed for 93–94days. No mortalities occurred. No treatment-related effects were identified for general condition, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, gross pathology, organ weights, and histopathology. Although statistically significant effects were noted for several endpoints, none was test-substance related. The no-observed-adverse-effect level (NOAEL) for WAF was based on consumption of the 100,000ppm diet, the highest dietary concentration tested, and was 4807mg/kg bw/d in male rats and 5366mg/kg bw/d in female rats. Additionally, WAF (⩽5000μg/plate) was not mutagenic in Salmonella typhimurium or Escherichia coli tester strains nor did WAF induce a clastogenic response in bone marrow from mice given a single oral dose (2000mg/kg bw). Further, WAF did not elicit skin sensitization in a repeat-insult dermal patch test which indicates little potential for food allergy.