Food waste is produced in all the phases of food life cycle, i.e., during agricultural production, industrial manufacturing, processing and distribution. Up to 42% of food waste is produced by household activities, 39% losses occurring in the food manufacturing industry and 14% in food service sector (ready-to-eat food, catering and restaurants), while 5% is lost during distribution.

Food waste is expected to rise to about 126 Mt by 2020, if any prevention policy or activities are not undertaken. It can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds and phytochemicals, which can be reused as nutraceuticals and functional ingredients.

Bioactive compounds comprise an excellent pool of molecules for the production of nutraceuticals, functional foods, and food additives. Fruits and vegetables represent the simplest form of functional foods because they are rich in several bioactive components.

Fruits containing polyphenols and carotenoids have been shown to have antioxidant activity and diminish the risk of developing certain types of cancer. The vegetable waste includes trimmings, peelings, stems, seeds, shells, bran and residues remaining after extraction of juice, oil, starch and sugar.

The animal-derived waste includes waste from dairy processing and seafood industry. The recovered biomolecules and by-products can be used to produce functional foods in food processing or in medicinal and pharmaceutical preparations.

Bioactive phytochemicals like sterols, tocopherols, carotenes, terpenes and polyphenols extracted from tomato by-products contain significant amounts of antioxidant activities. Therefore, these value adding components isolated from such waste can be used as natural antioxidants for the formulation of functional foods or can serve as additives in food products to extend their shelf-life.

The bioactive compounds present in mango peel are phenolic compounds, carotenoids, vitamin C and dietary fibre. It has been well recognised that these compounds contribute to lower the risk of cancer, cataracts, Alzheimer’s disease and Parkinson’s disease.

Wastes from wine making industry include biodegradable solids namely stems, skins, and seeds. Bioactive compounds comprise an excellent pool of molecules for the production of nutraceuticals, functional foods and food additives.

Fruits and vegetables represent the simplest form of functional foods because they are rich in several bioactive components. Fruits containing polyphenols and carotenoids have been shown to have antioxidant activity and diminish the risk of developing certain types of cancer. The vegetable waste includes trimmings, peelings, stems, seeds, shells, bran and residues remaining after extraction of juice, oil, starch and sugar.

The animal-derived waste includes waste from dairy processing and seafood industry. The recovered biomolecules and by-products can be used to produce functional foods in food processing or in medicinal and pharmaceutical preparations.

Bioactive phytochemicals like sterols, tocopherols, carotenes, terpenes and polyphenols extracted from tomato by-products contain significant amounts of antioxidant activities. Therefore, these value adding components isolated from such waste can be used as natural antioxidants for the formulation of functional foods or can serve as additives in food products to extend their shelf-life.

The bioactive compounds present in mango peel are phenolic compounds, carotenoids, vitamin C and dietary fibre. It has been well recognised that these compounds contribute to lower the risk of cancer, cataracts, Alzheimer’s disease and Parkinson’s disease. Wastes from wine making industry include biodegradable solids namely stems, skins, and seeds.

In this extraction approach, the suitably sized raw material is exposed to different organic solvents, which takes up soluble components of interest and also other flavouring and colouring agents such as anthocyanins which are anti-cancerous and anti-inflammatory. Samples are usually centrifuged and filtered to remove solid residue, and the extract could be used as additive, food supplement or for the preparation of functional foods.

Solvent extraction is beneficial compared to other methods due to low processing cost and ease of operation. However, this method uses toxic solvents, requires an evaporation/concentration step for recovery, and usually calls for large amounts of solvent and extended time to be carried out.

Moreover, the possibility of thermal degradation of natural bioactive components cannot be ignored due to the high temperatures of the solvents during the long times of extraction. Solvent extraction has been improved by other methods such as Soxhlet’s, ultrasound, or microwave extraction and SFE in order to obtain better yields.

Baysal et al. (2000) utilised ethanol for extraction of Lycopene and ß-carotene from tomato pomace containing dried and crushed skins (rich in lycopene and carotenes) and seeds of the fruit along with supercritical CO2 for resulting in recoveries of up to 50%.

As an indication, various reports of diverse array of bioactive compounds from specific food residues and availability of highly sensitive measurement tools provide a great opportunity to quantify metabolites in different range of food waste materials.

Based on higher quantity of specific bioactive components, a food waste byproduct could be utilised for its extraction using any of approaches discussed above. Utility of extraction methods is evident based on various reports and supercritical fluid extraction technology was proved to be very useful.