2.1 Summarize of raw materials and inoculum
Food waste was sampled from the students’ canteen during lunchtime in China Agricultural University every 2-3 weeks. Unsuitable materials, including bones, plastic, and chopsticks etc, were picked out by hand in laboratory and then the food waste was shattered with a blender (Joyoung JYLC012, China) for 5 minutes and stored in plastic bottles at 4°C. Maize straw was crushed by a small grinder (HC-1000Y2, China), sieved using a 40 mm sieve and stored. The inoculum was initially collected from an operated anaerobic plant with feedstock of cornstalk under thermophilic condition. The basic characteristics of food waste, maize straw and inoculum are shown in Table (1).