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398 Refining Biomass Residues for Sustainable Energy and Bioproducts

benefits. The concept about the formation of multiple products from one organic
waste is fully applicable on the bioconversion of food waste residues. The meta-
bolic pathway of microorganism decides the products formation. Waste orange
peels might be processed for the production of a various valuable products, such as
´
ethanol, industrial enzymes, methane, and other essential oils (Angel Siles Lo ´pez
et al., 2010). Industrial food waste is composed with a great amount of nutrients,
which acts as attractive feedstock for microbes to perform better activities.
Higher the living standards of urban peoples, higher would be the production of
catering waste. Along with carbohydrate, some amount of lipid is also present in
the catering waste which is a potential inhibitor of hydrolysis of
fermentable sugars. Oil isolation from catering waste is the important goal of the
pretreatment process. An industrial scale application of catering waste is not so fea-
sible as the composition of lipids and carbohydrates is unstable and also the com-
plexity of pretreatments results in the cost increment of the whole process (Yang
et al., 2015).

17.7 Valuable and economical by-products of fruit
industry

At present, the synthetic compounds utilized in the food as well as pharmaceutical
industry are replaced by phytochemicals to support the positive concern of human
health. Phytochemicals are the treasure of bioactive compounds with a great fortune
for human health. However, a large amount of waste, such as peels, seeds, and oil-
seeds, are produced during the processing of fruits and vegetables. Throwing or
dumping of these waste materials is a big issue as this waste is susceptible to micro-
bial impairment along with legal restrictions. The economically limited process of
drying, maintenance, and transport of fruit industry waste results the utilization of
waste as fertilizer in the agricultural field. Thus the new aspects about the utiliza-
tion of these wastes for the production of food additives with a huge amount of
nutrients have attracted the researchers along with economical benefits (Ðilas et al.,
2009). A number of compounds, such as sugars, organic acids, minerals, and dietary
fibers, along with phenolic compounds are released from the food industry as by-
product. Lignins, lignans, tannins, simple phenolic, and phenolic acids derivatives
represent the diversified group of phenolic compounds (Dewick, 2002). These phe-
nolic compounds possess strong antioxidant properties along with antitumoral, anti-
mutagenic, and cardioprotective abilities (Nijveldt et al., 2001; Van Acker et al.,
1998).
Apple pomace is produced as a by-product during the processing of fruit for
juice production, where pomace represents 25% 35% of the fruit (Schieber et al.,
2003). The recovery of pectin from apple pomace is considered to the best
suitable approach for both economical and ecological benefits. At present, apple
pectin possesses high gelling properties as compared to citurs pectin. But the brown
hue of apple pectin limits its utilization in light-color foods. The major extent of