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proteins, vitamins, antioxidative polyphenols (Wijngaard et al., 2012a,b; Friedman,
2006; Fewell and Roddick, 1993). Extraction of steroidal alkaloids from potato
peels may be one way to reduce the disposal problem along with a better option for
new pharmaceutical industry based on plants. A number of studies talk about the
health benefits of steroidal alkaloids, such as anticancer and antiinflammatory
effects, according the conditions of application (Friedman, 2006; Kenny et al.,
2013). Some strategies, such as chemical modifications, should be applied on steroi-
dal alkaloids to improve their bioactivities along with decrease in cytotoxic effect
on normal dividing cells. Proper extraction techniques should be there to retrieve a
sufficient amount of alkaloids for chemical modification. Some techniques, such as
ultrasound-assisted extraction, supercritical fluid extraction, solvent extraction, and
microwave-assisted extraction, are suitable for secondary metabolites extraction
from plants (Glisic et al., 2011; Vinatoru, 2001; Wijngaard, et al., 2012a,b). Out of
these, ultrasound-assisted extraction is inexpensive, ecological, and less time con-
suming (Virot et al., 2010). Cavity induced by ultrasound and glycoalkaloids pres-
ent inside the cell leads to disruption of cell wall responsible for the release of
intracellular components (Balachandran et al., 2006). For the better results through
ultrasound-extraction technique some parameters, such as time, temperature, and
amplitude of ultrasound, need to be optimized. But the optimization of all these
parameters for better extraction is costly and time consuming. However, there is a
statistical technique termed as response surface methodology to identify the
required optimum conditions for a particular response (Hossain et al., 2014).

17.9 Bioethanol production from sugarcane bagasse

Sugarcane bagasse, a rich source of lignocellulosic material, is a suitable industrial
waste for the development of biorefinery to produce fuels, chemicals, and other
materials for economical and environmental benefits. Similar to other lignocellu-
losic materials, bagasse also possesses cellulose, hemicellulose, and lignin, which
are difficult to separate as individual components. Therefore the production of
bioethanol involves four major steps, that is, pretreatment, to access cellulose;
hydrolysis, to release monomeric sugars with enzyme addition or acid catalyst; fer-
mentation, for ethanol production; and finally distillation approach, to recover prod-
uct (Margeot et al., 2009). Pretreatment process needs to be improved for efficient
and cost-effective conversion of biomass in fermentable sugars (Mosier et al.,
2005). In pretreatment, lime and alkaline hydrogen peroxide are the two
suitable chemicals in this direction and provide better results under moderate tem-
perature and pressure conditions (Fuentes et al., 2011). Raw material for ethanol
production leads to the generation of a great amount of solid and liquid residuals.
The liquid residuals are having a high concentration of pentoses, soluble and insolu-
ble lignin, and also an effluent named vinasse after the product recovery, whereas
lignin and hemicelluloses are the components of solid residuals (Fig. 17.3)(Rabelo
et al., 2011).