Study finds optimum shipping conditions vital to food quality

Related tags Folic acid

Scientists in the US have found that spinach stored for a long time
loses much of its nutrient content, a discovery that has
implications for the shipping of fresh food.

Luke LaBorde, associate professor of food science at Penn State University and graduate student Srilatha Pandrangi found that spinach stored at 39 degrees Fahrenheit loses its folate and carotenoid content at a slower rate than spinach stored at 50 and 68 degrees.

However, the spinach at 39 degrees still loses much of its nutrients after eight days. The average temperature of a refrigerator is 40 degrees.

"This has implications in the shipping process,"​ said LaBorde. Their research has been published in a recent issue of the Journal of Food Science.

There is such a high demand for fresh products that it places a heavy burden on the producers. If the spinach is coming from the other side of the country, then the produce might be kept at a warm temperature in a shipping truck for an extended period of time. By the time the spinach reaches the dinner table, much of the nutrient content might already be gone.

This is a critical time for food companies that rely on freight transportation. In addition to greater pressure to achieve complete traceability, there is currently a squeezed supply of refrigerated shipping containers in the US and elsewhere.

This has caused shipping rates to rise 10 per cent to 25 per cent since last spring, which has helped to push up prices. To accommodate such changes, food companies of all sizes have had to change their transportation processes and identify where saving can be made. Ensuring that more product makes it to the customer would be one way of achieving greater supply chain efficiency.

Suppliers should look at different ways of processing and packaging fresh foods. LaBorde noted that it is a fallacy that fresh spinach is always better than canned. This belief is not always true because, despite the damage done during the heating process for canned spinach, it may retain more of its nutrients than fresh spinach kept in the refrigerator for a few days.

The same holds true for frozen spinach. Frozen spinach retains more of its nutrients for a longer time than fresh spinach because of the lower temperatures at which it is kept.

Also, an attractive appearance does not mean that the spinach is still rich in nutrients. Spinach is prized because of its high nutrient content, particularly folate and carotenoids.

Folate is a vitamin B compound, responsible for producing and maintaining new cells in the body. Folate deficiency in pregnant women can lead to birth defects such as spina bifida. Spina bifida occurs in the first month of pregnancy when the spinal column does not close completely.

Carotenoids are most commonly associated with carrots and other red and orange vegetables, and they help support vision and protect eyes from UV damage. According to the FDA, spinach is high in both nutrients.

"Some people think that if the produce looks good, it has nutrients,"​ LaBorde said. "So people will stick the spinach in some ice water to fluff it up to look nice."

Related topics Food Safety & Quality

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