What are the main categories of food waste?

According to different sources, food waste is mainly divided into food waste and kitchen waste. The former is generated from leftovers from restaurants, canteens and other catering industries, and has the characteristics of large production, relatively concentrated quantity, and wide distribution. The latter mainly refers to the discarded scraps and leftovers from residents’ daily cooking, which come from thousands of households. Huge but relatively dispersed, the overall production volume exceeds that of catering waste.

Food waste can be divided into three parts according to the generation process and specific materials:
(1) Garbage formed during food processing
It is mainly the stems and leaves cut from vegetables, the soil contained in vegetables, fish scales, head and foot feathers of poultry, etc., which are left over from kitchen processing. This kind of garbage does not contain leftovers and oil-water separator garbage, contains very little oil, and has low economic value. Generally, no one collects this kind of garbage alone. This kind of garbage is mostly used for composting and producing organic fertilizers.
(2) Leftovers, commonly known as swill
This type of garbage is mainly leftover food and soup, and the oil extracted from it is called swill oil. The nature of this oil is basically neutral, the acid value is not high, and it can easily enter cooking oil. Pigs that grow up eating swill are called garbage pigs.
(3) Oil-water separator waste
This type of garbage is mainly caused by the small amount of food and some grease and detergent remaining in the tableware during the washing process of restaurants and hotels. They enter the oil-water separator with the washing water, and the oily substances float on the water surface, forming oil-water separator garbage. The grease content of oil-water separator waste is relatively high, generally between 20% and 80%. The oil content varies greatly depending on the hotel grade. The oil extracted from the oil-water separator is called "gutter oil". This type of oil has a higher freezing point and a higher acid value.

Among the three types of food waste, leftovers have the largest amount, and oil-water separator waste contains the most oil. The harm of leftover food is relatively small, but its moisture content and salt content are high, and it contains a large amount of organic nutrients. It is not suitable for direct landfill and incineration. If not handled properly, it may be possible to use these food wastes to raise poultry and livestock, and to recycle processed foods. , refining gutter oil and other issues that endanger food safety and even ecological safety.
Encourage everyone to pack leftovers and separate food waste.