Samples of PPW were supplied to the Biotechnology Laboratory
of the National Agricultural Research Foundation (N.AG.RE.F.) in
Greece and were dried. Moisture was determined by oven drying
at 105 C to a constant weight. Total sugars and total carbohydrates
were estimated by the colorimetric method of Dubois
et al. (1956). Protein was estimated by the Kjeldahl method by
multiplying residual nitrogen (N) by 6.25. Fat was determined by
the Soxhlet method (AOAC, 1995). Heavy metal analysis was performed
by atomic absorption according to the standard methods
for examination of water and wastewater, (APHA, 1989).