7. Conclusion
It has been reported that the waste utilization is the most
economical process for renewable energy production (biogas and
hydrogen/biohydrogen) and to clean the environment (Kothari
et al., 2010). This review has revealed that biohydrogen could be
efficiently produced from renewable waste feedstock like food
waste and food processing waste. These unused resources are being
continuously generated and can be made available to produce
biohydrogen whenever necessary.
Compared to the lipid, protein and cellulose components, the
carbohydrate fraction in food waste plays an important role in the
hydrolysis step during anaerobic degradation. Biohydrogen production
is also influenced by several environmental factors such as
pH, temperature, pre-treatment using seed culture and low
hydrogen partial pressure. Maintaining initial culture pH at 7.0 in
batch fermentation and at pH 5.5 in continuous fermentation had
been shown to enhance the activity of the hydrogenase enzyme
Yasin et al (2011). The other controlled environmental factors such
as the use of high temperature at 50e60 C and heat shock to the
seed culture could suppress hydrogen-consuming bacteria and
enhance the growth of hydrogen-producing bacteria. Thus, it is
suggested that enhanced biohydrogen production from food waste
and food processing waste can be achieved using controlled conditions
as elaborated in this review. On another perspective, dark
fermentation of food waste for biohydrogen production has the
potential to create an impact on the global energy market for the
production of energy from a cheap and renewable carbon source.