Page 461 - Refining Biomass Residues for Sustainable Energy and Bioproducts

Food industry waste biorefineries 419

to overcome the nutrient-lacking problem. The other treatments in the FW biorefin-
ery process are only for digester when the animal manure and sewage sludge are
available. Mono-digestion of FW causes the digester instability or failure of the AD
process at higher organic loading in a thermophilic condition. The failure of AD
process of FW happens due to ammonia inhibition and accumulation of VFAs
(Banks et al., 2012; Zhang et al., 2013). A few micronutrients, for example, nickel
(Ni), cobalt (Co), molybdenum (Mo), iron (Fe), selenium (Se), and tungsten (W),
are basic for methanogens, and zinc (Zn), copper (Cu), and manganese (Mn) are
basic for the hydrolytic microscopic organisms on the ground, in which these play a
significant role in the AD process of nourishment squander incorporate basic for
catalyst exercises and of explicit ecological condition (oxidative-reductive poten-
tial) for the microbial development (Romero-Gu ¨iza et al., 2016; Xu et al., 2017).

18.9 Innovations in food waste to biorefinery

The biomass change process determines the value of the substrates used for the con-
version. The operational expense and the estimation of the desirable products are
the two principal factors that decide the feasibility of a biomass conversion process.
It is subsequently important to assess the present patterns and late improvement of
innovation in the conversion of food-supply-chain waste. A large variety of finan-
cially imperative items, for example, biofuels, biocatalysts, organic acids, biopoly-
mers, nutraceuticals, and dietary fibers, have been developed from the
bioconversion of food-industry wastes (Galanakis, 2012). The modern progresses in
the food industry waste conversion process into valuable products are as follows:
Biofuels

Industrial enzymes

Bioactive/Nutraceuticals
Nanoparticles
Biodegradable plastics
Chitosan
Collagen

18.9.1 Biofuels
Production of ethanol from different sources has two basic steps: enzymatic hydro-
lysis of lignocellulose to release the fermentable sugars as products and conversion
of sugars into ethanol. Apart from these two steps, pretreatment is a necessary step
until the efficiency enzymatic hydrolysis is interrupted by recalcitrant substances in
lignocellulose (Ravindran and Jaiswal, 2016). In recent developments, bioethanol
was produced from FW by using enzyme carbohydrases and yeast called S. cerevi-
siae as the fermentative microorganism. Two types of fermentation were carried
out for the production of bioethanol from the FWs: SMF or separate hydrolysis and
fermentation, and SSF or simultaneous hydrolysis and fermentation. Glucoamylases