摘要
Approximately one quarter of the global edible food supply is wasted. The drivers of food waste can occur at any level between production, harvest, distribution, processing, and the consumer. While the drivers vary globally, the industrialized regions of North America, Europe, and Asia share similar situations; in each of these regions the largest loss of food waste occurs with the consumer, at approximately 51% of total waste generated. As a consequence, handling waste falls on municipal solid waste operations. In the United States, food waste constitutes 15% of the solid waste stream by weight, contributes 3.4 -107 t of carbon dioxide （CO2） equivalent emissions, and costs 1.9 billion USD in disposal fees. The levels of carbon, nutrients, and moisture in food waste make bioprocessing into higher value products an attractive method for mitigation. Opportunities include extraction of nutraceuticals and bioactive compounds, or conversion to a variety of volatile acids-including lactic, acetic, and propionic acids-that can be recovered and sold at a profit. The conversion of waste into volatile acids can be paired with bioen- ergy production, including hydrogen or biogas. This present review compares the potential for upgrading industrial food waste to either specialty products or methane. Higher value uses of industrial food waste could alleviate approximately 1.9-108 t of CO2 equivalent emissions. As an example, potato peel could be upgraded to lactic acid via fermentation to recover 5600 million USD per year, or could be converted to methane via anaerobic digestion, resulting in a revenue of 900 million USD per year. The potential value to be recovered is significant, and food-waste valorization will help to close the loop for various food industries.
全球大约有1/4的可食用的食物被浪费。食物浪费的驱动因素可以发生在生产、收获、分销、加工和消费之间的任何阶段。尽管全球各地的驱动因素不同,但在北美洲、欧洲和亚洲的工业化地区有着相类似的情况。在这些地区,食物浪费最严重的情况发生在消费者环节,他们产生了大约51%的食物废物。因此,处理垃圾的重点就落在了处理城市固体废物上。在美国,食物垃圾占固体废物流重量的15%,产生的CO_2当量排放量多达3.4×10~7 t,其处置费用高达19亿美元。利用食物垃圾中含有的碳、营养物和水分使垃圾转化成为高附加值产品,这对于减少浪费是一种具有吸引力的方法。提取食物垃圾中的营养物质和生物活性物质,或者把两者转化为各种挥发性酸碱(包括乳酸、乙酸和丙酸),便可以利用这些机会回收废物并将产品出售以获得利润。废物转化为挥发性酸的过程可以与生物能源(如氢气和沼气)生产相结合。本文将食物废物制备成某种高附加值产品或甲烷的潜力进行了对比。高价值利用食物垃圾可以减轻大约1.9×10~8 t CO_2当量排放。以马铃薯皮为例,通过发酵技术将其转化为乳酸可每年节省56亿美元,也可以通过厌氧消化转化为甲烷,每年增收9亿美元。回收食物废物潜在价值巨大,而食物废物的利用将有助于相关食物工业的闭路循环。
基金
supported by Hatch Fund (IND010677)
the Department of Agricultural and Biological Engineering at Purdue University
