The Protein Quality of Waste-grown Green Algae: I. Quality of Protein in Mixtures of Algae, Nonfat Powdered Milk, and Cereals

Abstract

The protein efficiency ratio (PER) was determined, as a measure of protein quality, on thick gruels and on baked products containing waste-grown green algae, a mixture of Scenedesmus quadricauda and Chlorella, spp., at a ratio of 10:1. Algae-cereal-nonfat dry milk mixtures (the algae and cereals boiled for 30 minutes to make a thick gruel) and milk added to the cooked product, were submitted to a taste panel to determine which of the cereals and what proportions of cereals and nonfat dry milk to use to mask the strong algal flavor most effectively. The mixtures containing varying proportions of algae, oatmeal, cracked wheat, and nonfat dry milk, were judged to be most palatable and were selected for the rat growth experiments. The algae-cereal-milk mixtures tested ranged from 22 to 29 g of protein/100 g and compared well with nonfat dried milk in protein quality. Calculated amino acid patterns compared favorably with the FAO reference protein except for methionine, which was lower than recommended by the FAO, but more than in INCAP vegetable mixture 9. Oatmeal and wholewheat breads, muffins, and peanut butter cookies containing algae were found to be palatable but were lower in the amount of protein (from 9.8 to 15 g/100 g) than were the algae-cereal-milk mixtures. There was loss in protein quality in the cookies as a result of baking.