â€œWhen people hear those numbers, they think thereâ€™s an easy solution â€” that we should just stop wasting food,â€� said Ned Spang, an assistant professor in the Department of Food Science and Technology at the University of California, Davis. â€œItâ€™s not that easy. Weâ€™re just starting to scratch the surface in really understanding the dynamics of this complicated problem.â€�
Spang led a team of researchers examining global food loss and waste in a study published in the journal Annual Reviews of Environment and Resources. The comprehensive review finds that there are larger systemic factors that drive food waste. The study points to the need to look at structural, cultural and social factors rather than only focusing on actions by individual producers and consumers.
Losses on the farm
Food waste isnâ€™t only what consumers scrape off their plate or leave to rot in their refrigerator. It begins on the farm and can be driven by a whole host of factors beyond the growerâ€™s control. Weather, pests, disease, low market prices or high labor costs all lead to food left in the field. Food that may look perfectly ripe and edible in the field may be too ripe by the time it reaches the consumer, so itâ€™s never harvested.
â€œPeople see food left in the field after harvest and think farmers are being wasteful,â€� said Spang. â€œItâ€™s an unfair characterization because it really does not make sense to harvest a crop if itâ€™s not going to get eaten.â€�
Itâ€™s not just consumers that are picky about their produce. Market-based quality or grade standards also play an unintentional role in food waste.
â€œA lot of the criteria are based on the appearance of the product and may not have anything to do with eating quality or utility of the product,â€� said Elizabeth Mitcham, a postharvest extension specialist and director of the Horticulture Innovation Lab at UC Davis.
Those standards mean food is left in the field if it isnâ€™t the right size, shape, color or maturity.
Losses after harvest
In developed countries, an estimated 20 percent of food is wasted on the farm or from improper or inadequate drying, storage, packaging and transportation.
Losses after harvest are most pronounced in less-developed countries, where an estimated 30 percent of food is wasted.
In tropical countries where humidity is an issue, food can rot or mold quickly if not dried properly or cooled. Growers and distributors often canâ€™t afford the energy costs of drying, adequate storage or refrigerated transportation. Inadequate road infrastructure can also lead to higher levels of spoilage.
Solutions to Farm-Level and Postharvest Food Waste
One potential solution to on-farm losses is to have groups and organizations collect leftover crops to distribute to food banks, a practice called gleaning. The problem is that the scale of food recovery through gleaning is very small compared to what is lost.
â€œIdentifying solutions that can work on a large scale is the real challenge,â€� Spang said.
Relaxing cosmetic quality standards for fruits and vegetables could prevent waste on farms on a large scale. Still, it would require consumers to overlook blemishes, bruises or imperfect produce so that there is a market for growers.