The emission of volatile organic compounds during the initial decomposition stage of food waste and its relationship with the bacterial community

Volatile organic compounds (VOCs) generated from food waste are serious environmental problems. The characteristics of VOCs and the corresponding indigenous microorganisms in the initial decomposition stage of food waste are not well known. This study investigates the concentration and composition of VOCs emitted from food waste at different temperatures and the correlation with bacterial communities at a laboratory scale. A total of 110 VOCs in seven categories were detected, and alcohols, primarily ethanol, were the main VOCs, followed by esters. Moreover, the amounts of total VOCs increased with increasing temperature due to the accelerated microbial activities and volatilisation. The proportion of alcohols decreased from 94.5% to 56.7%, while esters significantly increased when the temperature rose from 10 °C to 35 °C. Esters became the dominant VOC during fermentation of 35 °C after 24 h, while alcohols were the most dominant VOC throughout the experiment at 10 °C. The temperature clearly affected the bacterial community structure and composition in food waste. Furthermore, Weissella, Lactococcus, Shewanella, Klebsiella, Corynebacterium, and Acetobacter showed close relationships with alcohols, alkanes, olefins, terpenes, sulfur compounds, and aldehydes–ketones during the initial decomposition stage of food waste. Overall, the temperature of fermentation was an essential factor affecting the VOCs emission and corresponding bacterial communities in the initial decomposition stage of food waste.