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property, optical property, or even will be disintegrated resulting in the the unique characteristics like
the biological safety point of view, formation of cellulose nanocrystals, good mechanical and optical
these biopolymer matrices are being while the cellulose nanofibers properties, high aspect ratio, better
reinforced with various nanofillers are formed in the mechanical tensile strength, low thermal
which can improve mechanical, disintegration processes. The expansion coefficient, make CNCs
optical, antimicrobial, and barrier dimensions, morphology, and applications in various fields like
properties. At present times, a lot of crystallinity of the resulting CNCs biocomposites, food packaging
research has already been focused depends on the cellulosic source materials, as stabilizers in oil-
on various nanofillers from different – a pre-treatment process and water emulsion, paper making,
sources, and further research is hydrolysis condition such as acid coating additives, thermo-reversible
going on to find nanofiller reinforced concentration, acid to cellulose and tenable hydrogels making
biocomposites that can effectively ratio, reaction temperature and time. optically transparent films and
be utilized for food packaging Bacterial nanocelluloses produced biopharmaceutical applications
applications³. The nanofillers through certain enzymes which such as drug delivery and fabricating
(dimensions of < 100 nm) can be will degrade cellulose and also other temporary implants like sutures,
classified into organic or inorganic accompanying polymers (such as stents etc. In recent decades,
clays (Montmorillonite), natural pectin, hemicellulose and lignin)₂. the combination of cellulose
celluloses (nanocrystals, nanofibrils, These CNCs have drawn the attention nanotechnology with green solvent
bacterial nanocellulose), natural of researchers in the recent times, (alkaline/urea, ionic liquid, etc.)
biopolymers (chitosan), natural due to its unique properties like high technology made researchers
antimicrobial agents (nisin), metal surface area to volume ratio, light in expand cellulose applications in
(silver, copper, zinc), and metal weight, and excellent mechanical biomedical, energy storage, optical
oxides (e.g. TiO₂, ZnO, Ag₂O). These properties. These nanofillers can be fields too.
nanofillers for food packaging derived from the celluloses, which
applications are based on their are available widely as bio-waste Recently, IIT Kharagpur researchers
morphology and are classified as from the outer skin or peels, pulp, have developed cellulose
nanoparticles, nanofibrils, nanorods, seeds, etc., of fruits and vegetables; nanomaterials (CNCs), i.e., from
and nanotubes⁴. The utilization and from husks, hulls, shells and cucumber peels for producing eco-
of biodegradable polymers and straws of agro-crops like paddy, friendly commercial-grade food
nanofillers for bionanocomposite soya, wheat, pistachio, etc., during packaging materials. Researchers
films and packaging has opened new their harvesting, consumption, Dr. Jayeeta Mitra, Assistant
pathways for both academia and storage and agro-waste such as Professor and N. Sai Prasanna,
food industry to make sustainable sugarcane waste, mango pulp waste, research scholar at Dept. of
packaging materials that could cotton seeds waste, during industrial Agricultural and Food Engineering
replace conventional plastic processing. These biowastes can be have developed unique nanocrystals
materials causing environmental properly utilized for the engineering from the cellulose content of raw
pollution. One such nanofillers applications like production of CNCs, cucumber waste which can improve
were cellulose nanocrystals (CNCs), which later is identified as suitable mechanical, and barrier properties
emerged as strong, renewable, nanofillers to develop biocomposites of biopolymers. In India cucumber
unique and economic nanomaterials of sustainable packaging solutions is a native crop frequently used in
of near future. for the food industry applications. salads or pickles, cooked vegetables
or consumed raw, thus making its
These CNCs are derived from Since CNCs possesses modifiable cellulose content available in large
renewable and broadly available properties due to abundant hydroxyl volume and at low prices. After
nature resources (i.e., plant, animal, groups presence which resulted processing, cucumbers generated
bacterial, and algal biomass). Rich in better biodegradability and about 12% residual wastes either in
cellulosic sources subjected to biocompatibility, thus enable to the form of peels or whole slices.
controlled hydrolysis with strong protect environment from non- Research scholar N. Sai Prasanna
acids (like sulfuric or hydrochloric conventional plastic damage. reported that cucumber peels
acid) which selectively degrades Thereby, such nanocrystals when possessed greater cellulose content
the amorphous regions of cellulose reinforced as nanofillers in bio- (18.22%) than other peels waste. The
and produces more crystalline composites films, delivers effective cucumber peels were collected from
regions. Thus in cellulose hydrolysis, food packaging materials. Besides local hostels, dried and powdered,
hierarchical structure of cellulose food packaging applications, which later acid (HCl) treated,

Food Marketing & Technology 31 December 2020