Food waste is the single-largest component of the waste stream, in order to protect and safeguard the public health, useful and innovative recycling methods are investigated. The conversion of food wastes in value-added products is becoming a more economically viable and interesting practice. Food waste, collected in the distribution sector and citrus industries, was characterised for its potential as a raw material to use in fermentation processes. In this study, the production of single-cell protein (SCP) using food waste as a substrate was investigated. The purpose of this study has been to produce SCP from mixtures of food waste using Saccharomyces cerevisiae. The main fermentation test was carried out using a 25 l bioreactor. The utilisation of food waste can allow us to not only to reduce environmental pollution, but also to obtain value-added products such as protein supply for animal feed.

Today, food valorization represents an important challenge to environmental sustainability. Food waste can be used as a substrate for single cell protein production suitable for animal feed. In this study, animal and agricultural food waste, represented by fish, pineapple, banana, apple, and citrus peels, have been used simultaneously as a fermentation substrate for single cell protein production by Saccharomyces cerevisiae, to evaluate the possibility of using a multi complex substrate for a simultaneous biovalorization of different food waste. The fermentation process was implemented by the supplementation of a hydrolytic enzyme and nutrient to allow the best yeast growing conditions. At the end of the process, the final substrate was enriched in protein, reaching up to 40.19% of protein, making the multisubstrate useful for animal feed. The substrate was also investigated for crude lipid, ash, lignin, soluble and insoluble sugar. The substrate composition at the end of the fermentation process was represented by 14.46% of crude lipid, 1.08% ash, 6.29% lignin. Conversely, the soluble and insoluble sugars dropped down from 20.5% to 6.10% and 19.15% to 2.14%, respectively, at the end of the process.

Trace elemental levels were determined by inductively coupled plasma-mass spectrometry in muscle, eggs and sperm of 23 Thunnus thynnus fishes collected from May to August 2013 in the Mediterranean Sea. Zn, Mn, Fe, Cu, Cr, Ni and Se content was compared with Recommended Daily Allowances. Cd, Hg and Pb concentrations were below the maximum limits fixed by the European Legislation. Tuna food safety was evaluated considering Tolerable Weekly Intake (TWI) or Provisional Tolerable Weekly Intake for As, Hg, Cd and Pb. Only BMDL₀₁ data for As and Pb were calculated as established by the Joint FAO/WHO Expert Committed on Food Additives. The daily consumption of fresh tuna ensures a good intake of these elements. None of the tested samples surpassed the European maximum limits. Cd, Hg and Pb remained within safety margins, while As is slightly higher than the provisional TWI.