364

23 Biogeneration of Valuable Nanomaterials from Food and Other Wastes

Table 23.2

Cellulose-based bionanomaterials.

Bionanomaterial type

Type of waste used

Method

References

Cellulose nanocrystals

(CNCs)

Sugarcane bagasse

Acid hydrolysis

[31]

Potato peel waste

Acid hydrolysis

[32]

Pineapple leaves

Acid hydrolysis

[33]

Cellulose nanofibers

(CNFs)

Oil palm (Elaeis

guineensis) tree waste

Mechanical grinding of

cellulose

[34]

Sugar beet pulp waste

from sugar industry

High-shear

homogenizer

[35]

from carbohydrates (cellulose and hemicellulose) is achievable by pretreatment.

Nanocellulosic material synthesis using mild treatment is gaining more popularity.

Top-down synthesis of nanocellulose can be achieved by mechanical forces,

i.e. cryo-crushing, grinding, high-pressure homogenization, etc., which are quite

energy-intensive operations. Chemical methods like oxidation, acid hydrolysis,

etc., may be combined with mechanical treatments for increasing size reduction

efficiency with reduced energy consumption. Nanocellulosic materials can be of two

types, i.e. cellulose nanocrystals (CNCs), and cellulose nanofibres (CNFs) [25–27].

Principal method of CNC isolation from cellulose fibers is by acid hydrolysis [28].

Synthesis of CNFs was done by research group at University of Toronto, which was

reported in the year 2007. The synthesis of CNFs was done by combining a number

of treatments including chemical treatment, mechanical refining, homogenization,

and crushing of hydrated materials in liquid nitrogen [29]. Both CNC and CNF can

be produced from the plant cell walls. The CNCs are needle-like nanostructures,

which are produced by strong acid hydrolysis of natural organic materials like

bleached wood pulp, cotton, etc. On the other hand, CNFs are long flexible fiber

networks, which are synthesized by homogenization (high pressure), enzymatic

hydrolysis, or by mechanical action [30]. Synthesis of cellulose nanomaterials from

food and agricultural wastes has been summarized in the Table 23.2.

Nanocellulose synthesis is quite promising method for utilization of agricultural

waste for development of higher value products of economical interest.

23.3.2

Protein Nanoparticles

Peng et al. (2017) reported about utilization of rice bran waste for the synthesis of

rice bran albumin-chitosan nanoparticles, which were found to have application

in hydrophobic active agent delivery [36]. In another study, protein nanoparticles

were prepared from chicken feather waste by reduction and ultrasound treatment

[37]. Zein is extracted using polar solvents like ethanol or isopropanol, from corn

mill waste, i.e. gluten meal. Basically, zein is the water-insoluble protein found in

corn that has been generally recognized as safe (GRAS) by Food and Drug Admin-

istration (FDA). Zein is soluble in polar solvents and insoluble in water, but when