transesterification process, triglyceride reacts with alcohol to
form biodiesel and crude glycerol. Fruits and vegetable
wastes rich in lipids or oil such as rapeseed, palm, soybean,
and canola are used in biodiesel manufacture (Lee et al.
2010; Muniraj et al. 2015). The choice of feedstocks plays a
critical role in regulating the cost of diesel (Singh et al.
2012). Vegetable oils are countered with ethanol in the
existence of catalysts in biodiesel production (Stamenkovic
et al. 2011). Approximately 100% of the yield of biodiesel
was obtained by Lee et al. from canola oil waste employing
supercritical fluid extraction methods. Biodiesel can also be
recovered from microbial oils/lipids thus, oleaginous
microorganisms (capable of accumulating lipids) including
algae, yeast, and fungi can be probable feedstocks for
manufacturing biodiesel (Muniraj et al. 2015; Zhang et al.
2016). In the study of Surendra et al., larvae of Hermetia
illucens were used in efficient organic waste management,
and the larvae were cultivated on food trash to yield fat plus
prepupae rich in protein. These black soldier fly prepupae
derived oil was converted into high-quality biodiesel
(Surendra et al. 2016).
4.7 Bioplastics
Bioplastics are the biopolymers as plastic material having
mechanical endurance, easy processability, chemical apathy,
weightlessness, flexibility, and produced from renewable
sources. Bioplastics are biodegradable and can be synthesized from FVWs. Biopolymers have obviously prevailing
starch, cellulose, protein, lignin, natural rubber-like molecules. The main important component of bioplastic is
polyesters and the biodegradable polyesters are in different
commercial forms. The commercial biodegradable polyesters are as follows; polybutylene succinate adipate (PBSA),
polylactic acid (PLA), polyhydroxyalkanoate (PHA),
polyglycolic acid (PGA), polybutylene succinate (PBS),
aliphatic–aromatic copolyesters (AAC), polybutylene
adipate/terephthalate
(PBAT),
and
polymethylene
adipate/terephthalate (PTMAT). Among these, PLA and
PHA are the most important synthetic bioplastics (de Moura
et al. 2017; Esparza et al. 2020). PLA can be obtained from
the processing of renewable carbohydrate sources like corn
into dextrose and further followed by bacterial fermentation
in which dextrose is converted into lactic acid. PLA is
biodegradable, decomposing to give H 2 O, CO 2 , and humus
(Drumright et al. 2000). Bacteria that are employed in the
production of PLA belongs to Lactobacillus genus such as L.
acidophilus, L. amylophilus, L. casei, L. maltaromicus, L.
salivarius, L. delbrueckii, L. bavaricus, and L. jensenii
(Nampoothiri et al. 2010). FVWs like sugarcane and cassava
bagasse, potato wastes, tapioca, corn stover, carrot waste,
beet syrup, sweet sorghum, etc., may be used for PLA
invention. PLA is applied in releasing controlled drugs,
fixing bone fixation, composites implantation, packaging,
coating paper, releasing sustained pesticides and fertilizers,
etc. (Nampoothiri et al. 2010; Castro-Aguirre et al. 2016).
PHAs are the second most essential synthetic bioplastics
after PLA (Esparza et al. 2020). PHAs are polyesters that are
synthesized from the polymerization of various hydroxy
alkanoic acids by microorganisms. These microorganisms
accumulate this biopolymer in the cytoplasm as stored
energy. Some bacteria and filamentous fungi can produce
enzymes to decompose PHAs. Pomace from fruits like
apricot, cherries, grapes can be a carbon source and recycled
culinary oil as a precursor for PHAs production (Follonier
et al. 2014). PHA-producing microbes are Ralstonia eutropha, Pseudomonas oleovorans, Chromatium vinosum,
Thiocapsapfennigii, etc., and these microbes have PHA
synthase enzyme. Bioplastic has a wide range of applications
like in manufacturing latex paints, in medical application
with tissue engineering, to obtain enantiomeric pure
hydroxyalkanoic acid, etc. (Steinbüchel 2001).
4.8 Exopolysaccharides (EPS)
EPS are polysaccharides secreted by microorganisms outside
the cell or in the medium throughout the growth phase and
occur as capsule or slime. EPS varies with exceptional
physical and chemical characteristics. EPS manufactured by
lactic acid bacteria are considered harmless and used as food
additives or as functional food ingredients (de Vuyst et al.
2001). However, few EPS can provide infectious and
immunogenicity which differs in different species of
microorganisms (Weiner et al. 1995). EPS can be
homopolysaccharides like D-fructose and D-glucose having
indistinguishable monosaccharide units and heteropolysaccharides consisting of different monosaccharides in distinctive proportions (de Vuyst et al. 2001). EPS can be used as a
corporal barrier, in cell/cell identification and cooperation, a
rejoinder to conservational stress, and in biofilm
expansion/adherence (Weiner et al. 1995). Some of the
microbial EPS advantageous in industries are dextran, xanthan, pullulan, and gellan secreted by Leuconostoc mesenteroides, Xanthomonas campestris, and Sphingomonas
paucimobilis, respectively. Microbial EPS are particularly
used to improve the consistency, rheology, and flavoring
properties of dairy products that increase both wellbeing and
financial benefits (Esparza et al. 2020; de Vuyst et al. 2001).
The Food and Drug Authority approved xanthan as a food
additive biopolymer after that the insistence of xanthan has
been increasing. Xanthan is used in cosmetics, pharmaceutical, textile, petroleum, and especially the food industry
(Esparza et al. 2020). Pullulan is a decomposable polysaccharide found in the culture medium of Aureobasidium
Bioconversion of Fruits and Vegetables Wastes …
157
form biodiesel and crude glycerol. Fruits and vegetable
wastes rich in lipids or oil such as rapeseed, palm, soybean,
and canola are used in biodiesel manufacture (Lee et al.
2010; Muniraj et al. 2015). The choice of feedstocks plays a
critical role in regulating the cost of diesel (Singh et al.
2012). Vegetable oils are countered with ethanol in the
existence of catalysts in biodiesel production (Stamenkovic
et al. 2011). Approximately 100% of the yield of biodiesel
was obtained by Lee et al. from canola oil waste employing
supercritical fluid extraction methods. Biodiesel can also be
recovered from microbial oils/lipids thus, oleaginous
microorganisms (capable of accumulating lipids) including
algae, yeast, and fungi can be probable feedstocks for
manufacturing biodiesel (Muniraj et al. 2015; Zhang et al.
2016). In the study of Surendra et al., larvae of Hermetia
illucens were used in efficient organic waste management,
and the larvae were cultivated on food trash to yield fat plus
prepupae rich in protein. These black soldier fly prepupae
derived oil was converted into high-quality biodiesel
(Surendra et al. 2016).
4.7 Bioplastics
Bioplastics are the biopolymers as plastic material having
mechanical endurance, easy processability, chemical apathy,
weightlessness, flexibility, and produced from renewable
sources. Bioplastics are biodegradable and can be synthesized from FVWs. Biopolymers have obviously prevailing
starch, cellulose, protein, lignin, natural rubber-like molecules. The main important component of bioplastic is
polyesters and the biodegradable polyesters are in different
commercial forms. The commercial biodegradable polyesters are as follows; polybutylene succinate adipate (PBSA),
polylactic acid (PLA), polyhydroxyalkanoate (PHA),
polyglycolic acid (PGA), polybutylene succinate (PBS),
aliphatic–aromatic copolyesters (AAC), polybutylene
adipate/terephthalate
(PBAT),
and
polymethylene
adipate/terephthalate (PTMAT). Among these, PLA and
PHA are the most important synthetic bioplastics (de Moura
et al. 2017; Esparza et al. 2020). PLA can be obtained from
the processing of renewable carbohydrate sources like corn
into dextrose and further followed by bacterial fermentation
in which dextrose is converted into lactic acid. PLA is
biodegradable, decomposing to give H 2 O, CO 2 , and humus
(Drumright et al. 2000). Bacteria that are employed in the
production of PLA belongs to Lactobacillus genus such as L.
acidophilus, L. amylophilus, L. casei, L. maltaromicus, L.
salivarius, L. delbrueckii, L. bavaricus, and L. jensenii
(Nampoothiri et al. 2010). FVWs like sugarcane and cassava
bagasse, potato wastes, tapioca, corn stover, carrot waste,
beet syrup, sweet sorghum, etc., may be used for PLA
invention. PLA is applied in releasing controlled drugs,
fixing bone fixation, composites implantation, packaging,
coating paper, releasing sustained pesticides and fertilizers,
etc. (Nampoothiri et al. 2010; Castro-Aguirre et al. 2016).
PHAs are the second most essential synthetic bioplastics
after PLA (Esparza et al. 2020). PHAs are polyesters that are
synthesized from the polymerization of various hydroxy
alkanoic acids by microorganisms. These microorganisms
accumulate this biopolymer in the cytoplasm as stored
energy. Some bacteria and filamentous fungi can produce
enzymes to decompose PHAs. Pomace from fruits like
apricot, cherries, grapes can be a carbon source and recycled
culinary oil as a precursor for PHAs production (Follonier
et al. 2014). PHA-producing microbes are Ralstonia eutropha, Pseudomonas oleovorans, Chromatium vinosum,
Thiocapsapfennigii, etc., and these microbes have PHA
synthase enzyme. Bioplastic has a wide range of applications
like in manufacturing latex paints, in medical application
with tissue engineering, to obtain enantiomeric pure
hydroxyalkanoic acid, etc. (Steinbüchel 2001).
4.8 Exopolysaccharides (EPS)
EPS are polysaccharides secreted by microorganisms outside
the cell or in the medium throughout the growth phase and
occur as capsule or slime. EPS varies with exceptional
physical and chemical characteristics. EPS manufactured by
lactic acid bacteria are considered harmless and used as food
additives or as functional food ingredients (de Vuyst et al.
2001). However, few EPS can provide infectious and
immunogenicity which differs in different species of
microorganisms (Weiner et al. 1995). EPS can be
homopolysaccharides like D-fructose and D-glucose having
indistinguishable monosaccharide units and heteropolysaccharides consisting of different monosaccharides in distinctive proportions (de Vuyst et al. 2001). EPS can be used as a
corporal barrier, in cell/cell identification and cooperation, a
rejoinder to conservational stress, and in biofilm
expansion/adherence (Weiner et al. 1995). Some of the
microbial EPS advantageous in industries are dextran, xanthan, pullulan, and gellan secreted by Leuconostoc mesenteroides, Xanthomonas campestris, and Sphingomonas
paucimobilis, respectively. Microbial EPS are particularly
used to improve the consistency, rheology, and flavoring
properties of dairy products that increase both wellbeing and
financial benefits (Esparza et al. 2020; de Vuyst et al. 2001).
The Food and Drug Authority approved xanthan as a food
additive biopolymer after that the insistence of xanthan has
been increasing. Xanthan is used in cosmetics, pharmaceutical, textile, petroleum, and especially the food industry
(Esparza et al. 2020). Pullulan is a decomposable polysaccharide found in the culture medium of Aureobasidium
Bioconversion of Fruits and Vegetables Wastes …
157