Dec 1, 20173 min read

Shanghai TV Feature: When buying nuts, choosing the right packaging is key!

Originally published on Shanghai TV: Dr. Who for China's Health Conference (Double 11 Event)

Featuring Food Scientist: Ma, Zhiying using the MOCON Dansensor CheckPoint 3 to test MAP packaged nuts for product safety, freshness and shelf life.

"Double 11" is China’s largest online shopping festival put on by Alibaba, a Chinese e-commerce giant and is held on “Singles Day”. In 2016 Retailers on Alibaba's platforms had recorded $17.8 billion worth of gross merchandise volume (GMV),, surging nearly 30% over the previous year. However, the number of online shopping complaints rose by 35% last year, exceeding the turnover. Among them, food accounted for 30% of the total complaints!

Out of the 30% of food related complaints, most were related to one certain type of food – Nuts!

Oxygen test readings on MOCON CheckPoint 3

So, because nuts were the largest food group with complaints we want to look into why this is and what is making the nuts go bad? Also, are there any safety risks related to eating nuts and if so, what?

First, let’s look at the statistics regarding those who complained/returned nut products.

Last year, "Double 11" had the highest sales of nuts and it has been found that the occurrence of mold exceeded 1.8 times than the standard allowed! What is the reason for this, why is mold so prevalent in nuts?

Food safety expert Mr. Ma explains that the factors for mold growth are moisture, high temperature and oxygen. The key factor being oxygen!

To do an experiment, Mr. Ma has chosen some of the top nut products to test. The next question came, among the following three packages, which package do you think the safest? Is there any oxygen in the inflated package?

Testing three different types of packaging

Field test results, using the MOCON Dansensor CheckPoint 3® to measure the O2 headspace tell us that the oxygen content for the three nut products were (from left to right) 0.4%, 14.2% and 7.0%, respectively. The higher the oxygen content, the more susceptible nuts are to oxidation, leaving them more prone to mold, therefore increasing the risk of mold, bacteria, and illness!

CheckPoint 3 Test Results of each nut package

So for packaging that is so similar...

- Why are the differences so huge?

- How exactly can we as consumers safely select nuts?

- And how can food producers ensure safe and healthy products?

Food safety expert Mr. Ma tells you that flushing your package with fresh nitrogen has less risk. In addition, it is also a great trick for consumers to see whether the product label contains the phrase "Oxygen Scavenger". If so, this means the manufacturer has taken measures to ensure Oxygen stays out of the package and the product stays fresh and free of mold. Experts remind, depending upon your actual consumption situation, it is more reliable to purchase individually packed nuts containing just one serving rather than those you may have to open and close many times and will require a longer shelf life.

As mentioned earlier, in addition to the oxygen content of the package, there are other key factors that affect nut products. The TV show reporter purchased three peanut samples with similar production dates from the same large supermarket and sent them to the laboratory for Peroxide Value testing.

Test results showed that among the three samples, the largest difference in Peroxide Value was 13 times!

According to reports, for the oxygen content of the initial packaging of the nut, it often takes more than six months for nuts to be oxidized. If the storage environment is similar and the production date is similar, why was there such a big difference between the three packs of peanuts?

The answer comes down to the oxygen permeability of the packaging materials used! Nut products on the market use many different packaging materials, and each material has a different oxygen transmission rate or permeability rate.

Oxygen permeability of barrier materials

So even though the nuts had a similar manufacturing date and storage conditions, because different materials were used to package them this will cause different amounts of oxygen to pass through each package, hence directly affecting the safety and freshness of the nuts!

So, what type of packaging material is the best for packaging nut products?

Through testing and many years’ experience with food packaging, Mr. Ma explains that aluminum foil composite material has low oxygen permeability, and is also moisture-proof, making it the best choice for the packaging of nuts. The double plastic packaging is acceptable, while the single plastic packaging does not provide a great barrier and leaves the safety of the nuts at a much higher risk for mold. Hopefully this information we have discovered will help everyone make better and more careful decisions when selecting snack nuts or any packaged food for that matter.