Evaluation of products of bioconversion for human consumption

The evaluation of bioconversion products to be used for food must take into account four main problems. These are (i) toxicology, (ii) public health aspects, (iii) food technology, and (iv) nutritional quality. The first two are discussed elsewhere in this volume, while the third, consisting mainly of functionality and organoleptic properties, will be only briefly mentioned here. The main emphasis will be given to the fourth consideration - the nutritive value of potential products in terms of their physiological effects and protein quality.

With respect to nutritional evaluation of novel or nonconventional protein sources for human consumption, the Protein Advisory Group (PAG) documents (2 - 6) outline the methods of procedure, including standards for chemical, bacteriological, and toxicological quality, as well as procedures for feeding tests, including acceptability, tolerance, and protein quality evaluation. Therefore, if bioconversion products produced for human feeding meet these standards, they can be considered acceptable for use as components of food. Four products potentially useful as food sources are products derived from animals fed bioconversion products, conventional fermented foods as used in the Far East, algae, and other single-cell proteins. Before discussing them individually, present methods of protein quality evaluation will be briefly described.