Tue, Mar 18, 2014
Est. Reading Time min
On a recent exploration of our refrigerator, my spouse uncovered a jar of mayonnaise past its expiration date. Although it still looked okay, we decided to chuck it. Upon reflection, it did seem unlikely to me that food could have an on/off-good/bad switch, so I decided to find out what expiration dates really mean.
The possibility that there might be Salmonella bacteria lurking in raw eggs, gives mayonnaise a dodgy reputation. But vinegar or lemon juice acidifies the mixture enough to kill off Salmonella. So commercial mayonnaise should be fine, though it lacks the love of homemade. But what about the expiry date?
Foods that you can still recognize aspart of the food chain, like meats and eggs, tend to bemore perishable and have a sell-by date. They are more susceptible to chemical reactions and microbial activity that can change them over time. Heat speeds activity up and cold slows it down. Freezing can stop some microbes, but damages certain kinds of food.
For most processed foods, expiration or best before dates are voluntary indications of how long manufacturers think the food will be at its best. As a side note on these date codes, JN is for June and JA is for January. Manufacturers have R&D people who test samples of new products under various conditions to see if they will last.
But the best before date is not a safety guide. If it were, I would probably forgetand then get sick. AHarvard study found that 90% of Americans think they need to throw out food unnecessarily, because of this misconception. The food industry just sells more stuff through this misunderstanding.
An unopened container of mayonnaise could be good indefinitely. This is a little disconcerting, actually. However, once opened, the mayo could be contaminated and all bets are off. But if the jar gets tightly sealed and refrigerated,mayonnaisecan lasttwo or three monthsafter opening—even after the best before date, according to Still TastyandShelf Life Advice. It might get a little yellowy or lumpy, but should still be okay. However,Eat By Date only gives an unopened jar a week past its expiry date and an a month after it had been opened. If food starts to look or smell off, then chuck it. Health Canada says, “When in doubt, throw it out.”
We should probably pitch out processed foods for all kinds of reasons, but the expiration date does not seem to be one of them.
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As someone deeply immersed in the world of food safety and expiration dates, it's clear that misconceptions abound regarding the longevity of various food items. Let me shed light on the intricacies of expiration dates and the science behind the safety of products like mayonnaise.
First and foremost, the article touches on the potential threat of Salmonella in raw eggs, a concern often associated with mayonnaise. It accurately points out that the acidity of ingredients like vinegar or lemon juice in commercial mayonnaise acts as a safeguard against Salmonella. This is a critical insight that dispels common fears about the safety of store-bought mayonnaise.
The concept of sell-by dates for meats and eggs is also well-addressed. These items, being part of the food chain, are more perishable due to their susceptibility to chemical reactions and microbial activity. Understanding the impact of temperature on food spoilage, with heat accelerating activity and cold slowing it down, is crucial for consumers to make informed decisions.
Furthermore, the distinction between best before dates and safety guidelines is a key point. The article correctly notes that best before dates for processed foods are voluntary indications by manufacturers about the period during which they believe the product will be at its best. This isn't a strict safety measure, as evidenced by a Harvard study revealing that many people erroneously discard food prematurely due to a misunderstanding of these dates.
The discussion on the potential longevity of unopened containers of mayonnaise adds another layer to the narrative. While it might be disconcerting to realize that an unopened jar could be good indefinitely, it highlights the importance of proper storage conditions. However, once opened, the mayonnaise becomes susceptible to contamination, and the article provides varying perspectives on how long it can last after the best before date.
The diverse viewpoints from sources like Still Tasty, Shelf Life Advice, and Eat By Date contribute to a nuanced understanding of mayonnaise shelf life. It's noteworthy that while Still Tasty and Shelf Life Advice suggest a more extended period for opened mayonnaise, Eat By Date adopts a more cautious approach, emphasizing the importance of visual and olfactory cues in determining freshness.
In conclusion, the article encourages a critical approach to expiration dates, emphasizing that they are not definitive safety guides. This aligns with the broader narrative that unnecessary food waste often results from misconceptions about expiration dates. The call to pitch out processed foods for various reasons, with expiration date alone not being a primary factor, is a sound piece of advice based on a comprehensive understanding of food safety principles.
