Waste is a significant issue for the vegetable industry. Waste can include the non-harvested parts of plants, off-cuts and by-products, product which does not meet retailer specifications and product that is abandoned before harvest due to low market prices.

This study has estimated the types and quantities of waste occurring in the Australian vegetable industry. The results suggest that over 277,000 tonnes of the major vegetable lines, representing around 25% of production, is wasted each year. Most waste is due to failure to meet strict retail quality specifications. This otherwise edible product is usually dumped, used for stock feed, or rotary hoed back into the soil. The cost of this waste to growers is estimated at close to $155million annually.

The best way to reduce waste would be to increase demand for fresh vegetables. Most Australians eat less than 3 serves of vegetables a day and only 8% eat the recommended 5 daily serves. There are therefore major opportunities to increase consumption, with corresponding benefits for public health.

Other options for using vegetable wastes include:

• Extraction of bio-active compounds for use in nutritional supplements and nutraceuticals, or as natural food colourants
• Extraction of volatile compounds to use as natural flavourings in food manufacturing
• Dietary fibre production, potentially including bio-active compounds, for use in fortified foods and supplements
• Producing insects such as mealworms or black soldier fly larvae as high protein ingredients in feeds for aquaculture
• High quality animal feed production through silage or aerobic fermentation
• On farm electricity generation using biogas produced from anaerobic digestion of organic materials
• Combustion without oxygen (pyrolysis), producing electricity as well as a stable form of carbon (biochar) which can be used to increase soil fertility
• Composting with earthworms (vermicompost) production to improve soil structure and fertility

A number of these options would appear to offer economic opportunities for Australian vegetable growers.