The uncontrolled discharge of large amounts of food waste (FW) causes severe environmental pollution
in many countries. Within different possible treatment routes, anaerobic digestion (AD) of FW into
biogas, is a proven and effective solution for FW treatment and valorization. The present paper reviews
the characteristics of FW, the principles of AD, the process parameters, and two approaches (pretreatment
and co-digestion) for enhancing AD of food waste. Among the successive digestion reactions,
hydrolysis is considered to be the rate-limiting step. To enhance the performance of AD, several physical,
thermo-chemical, biological or combined pretreatments are reviewed. Moreover, a promising way for
improving the performance of AD is the co-digestion of FW with other organic substrates, as confirmed
by numerous studies, where a higher buffer capacity and an optimum nutrient balance enhance the
biogas/methane yields of the co-digestion system.