Coffee, as a popular drink worldwide, has become a must-have for many people at home and work. Some time ago, the news of a coffee chain brand using expired ingredients to make coffee rattled everyone’s sensitive nerves about coffee food safety. On the one hand, people are very concerned about the safety of coffee made with these expired ingredients, on the other hand, they also have doubts about long-term coffee consumption: can coffee still be good to drink in the end? What are the food safety risks involved?
Coffee beans are the kernels of the coffee tree fruit, or to be precise, the endosperm part of the coffee seed. After being harvested, the coffee fruit needs to undergo multiple treatments before it can be turned into dried coffee beans for storage. In terms of cultivation, similar to other agricultural products, coffee fruits are exposed to the risk of pesticide residues and excessive heavy metals. The oil content of coffee beans is 8% to 13%, which is relatively high among plant seeds. So in the process of initial processing and storage, coffee still has to face all the risks faced by the storage of high oil agricultural products, including lipid peroxidation, fungal contamination, microbial contamination, and elevated acid prices.
However, after reasonable dehulling and drying and proper packaging, coffee beans have a relatively long shelf life, which may be related to their high internal chlorogenic acid content. Under the right environment, packaged coffee beans can be stored for 1 to 2 years, which is evident from the fact that the shelf life of coffee beans has been abolished by the EU in previous years. However, in a more hostile environment, such as storage in a space with high temperature, high humidity and prone to mold, the safe storage period of coffee beans will be rapidly shortened.
Usually, the risk of this aspect of storage is managed by the merchant’s quality control department. Nowadays, large-scale origins have better handling and storage conditions, as well as more stringent factory quality testing. So, at the raw material level, we don’t have much need to worry about the safety risks of coffee beans, but if we buy raw coffee beans ourselves and need to store them ourselves, we have to consider the risks that come with these storage conditions.
After the raw coffee beans are roasted, there will be an optimal appreciation period and shelf life. Generally speaking, coffee beans need to have a venting period of about 48 hours after roasting to let out the carbon dioxide and some stray gases produced during the roasting process, as well as to let out the fat and aromatic substances. The best time to enjoy the flavor is usually within 3 to 4 weeks after the beans have been roasted for 48 hours. During this time, the coffee beans have the best aroma and the most flavorful coffee is ground.
After this period, the aroma of the beans gradually dissipates and fat oxidation begins to increase. At this point, the coffee beans are still drinkable, but the quality has decreased. As long as the coffee beans are stored properly and not contaminated during the shelf life, the quality of the coffee beans can be stabilized above the edible standard. Once the shelf life has passed, then there is no guarantee that it is safe for consumption. Generally, after roasting, coffee beans should be sealed and stored in a cool place away from light. If they are well sealed, they have a shelf life of more than one year.
For coffee that has been powdered, it is more prone to oxidation and contamination by microorganisms due to its greater exposure to air, so it should be stored more strictly. Even within the shelf life, if contaminated by bacteria or fungi, such coffee beans may lead to food poisoning. Hot water brewing does not necessarily kill all germs, especially pathogenic bacteria with budding spores. Also, bacteria or fungi may release toxins as they grow. When contaminated with peroxide or microorganisms, the coffee beans may become gassy and baggy when vacuum sealed, the color of the coffee may change, the grind may become more lumpy, and the brew may develop an unpleasant odor.
If this happens, the coffee will not be suitable for drinking. However, coffee beans are a relatively fast-consuming ingredient for these chain brands, and some of the coffee is machine-ground coffee beans, so the likelihood of risk is relatively small.
In this news story featuring coffee, the expired ingredients used by the service staff were mainly cream, chocolate liquor, fruit pulp, matcha liquid, and expired snacks. Although the quality of these products themselves are relatively stable and generally do not deteriorate quickly within 48 hours. However, what should not be overlooked is that these products will come into contact with the outside environment as soon as the packaging is opened, especially chocolate liquids and matcha liquids, which require the addition of large amounts of water for successful blending, and this process itself introduces a relatively large number of microorganisms.
In addition, these foods contain a large amount of sugar and oil, which is a good culture medium for microorganisms. Within 48 hours after blending, the number of microbial growth can be maintained within an acceptable range, but after 48 hours, microbial proliferation may show a multiplicative trend, thus posing a food safety hazard. If the blending can be continued in the low-temperature refrigerator after storage, it is still relatively safe.
We know that although there are accidental factors in the emergence of some food safety problems, if the scientific laws are ignored for a long time, there is no bottom line and irregularities, then the emergence of food safety problems is an inevitability. I’m sure there have been some customers who have experienced discomfort after consuming at the coffee shop, but have not associated this discomfort with expired ingredients. The merchant’s indifference to customer food safety was shown at every turn in the incident, much to the public’s dismay. On the one hand, people are very concerned about the safety of the coffee made with these ingredients, and on the other hand, they are outraged by this act of hoodwinking and deceiving customers in exchange for profits by using the second best. This exposure is tantamount to a big warning to the business: corporate interests and profits must be put after the safety of customers, otherwise they will be abandoned by customers and the times.