524

34 Agri and Food Waste Valorization Through the Production of Biochemicals and Packaging Materials

antioxidant and antimicrobial in nature. The recovery of such biochemicals from

AFW assumes primary priority as this is a high-value product.

AFWs have the potential to be a valuable source of biomolecules [23] like fatty

acids and triacylglycerides, carboxylic acids (acetic, glycolic, oxalic, 3-hydroxy-

propionic, fumaric, succinic, asperic, malic, butyric, levulinic, itaconic, glutamic,

adipic, citric and gluconic acids), olefins (ethylene and unsaturated fatty acids), alco-

hols (ethanol, glycerol, propane diols, 1,2,4-butane triol, 2,3-butane diol, 1-butanol

and sorbitols), enzymes (protease, lipase, cellulose, phytase, amylase, lignisase and

xylanase), L-glutaminase, citric acid, lactic acid, gallic acid and gibberellic acid

and other chemicals such as sucrose, furfural, acetone, lysine, antibiotics,

polyhydroxyalkanoates (PHA), poly-γ-glutamate and aromas [5].

This enormous and diverse variety of potential biochemicals has led to the evo-

lution of the biorefinery concept which uses these AFWs to generate chemicals of

commercial importance. Central to the theme of biorefinery concept is the sequen-

tial, integrated and multifunctional processes used to exploit the AFW thereby gen-

erating commercial intermediates and end products ultimately achieving zero waste.

It is also imperative that such a concept should be economically feasible and envi-

ronmentally sustainable with a lower carbon footprint [24].

34.5.1

Functional Phytochemicals

Functional phytochemicals have some beneficial aspects for human health and

nutrition and can have antioxidants, antimicrobials, antivirals and antiplatelet

properties, cytotoxicity, anti-inflammatory compounds, etc.

Some of the wastes having the potential for extraction of these types of phyto-

chemicals are waste peels of Chinese yam (Dioscorea batatas) rich in phenanthrenes

[25], the extracts from mango byproducts (peel, husk seed and seed mango) rich in

monogalloyl compounds, tetra- and penta-galloylglucose, ellagic acid, mangiferin

and benzophenones such as maclurin derivatives and iriflophenone glucoside [26],

bioactive peptides from fish waste [27], wine-making wastes for their antioxidant

potential [28], etc. Antioxidants and bioactive compounds can also be extracted from

citrus, pomegranate and lemon peel wastes [29–31]. Antioxidants and functional

phytochemicals are increasingly being sought after for their various therapeutic and

functional values and have a large potential.

34.5.2

Industrial-Relevant Biochemicals

Many industrially relevant biochemicals have also been produced from AFW. Pectin

has been extracted from apple pomace, citrus peel, sugar beet, sunflower heads and

watermelon [32, 33] which have gelling, thickening and stabilizing properties in

foods. Production of biosurfactants from orange peel [34] dairy and food processing

wastes [35] has been attempted employing solid fermentation which has a range

of industrial applications as in adhesives, flocculating, wetting, foaming agents,

de-emulsifiers, penetrants and also have applications in bioremediation. The use of