Milk Carton ‘Sell-by’ Date May Become More Precise
Cornell University food scientists have recently created a new model for creating more science-based sell-by date on milk cartons (Cornell University, 2018).
The handling of mild after it has been removed from the cow is very important in determining self-stability. Temperature indicators have been devised to detect temperature history. At the time of this study, it showed the relationship between the temperature at storage and shelf-life and quality of market level milk.
Milk distributors even then were required to have a dated code stamped on containers to help consumers with shelf-life and to help grocery stores keep milk rotated. Even then, there were issues with storage temperature at stores were uncontrolled and rarely monitored. To compound this many manufacturers still used clear containers [in 1983] making them susceptible to light-induced oxidations.
At the time of the study, there wasn’t a method to know the temperature history of storage. The thermometer may say 4℃ (39.2℉) but there is no way of knowing if it has always been that temperature. This study is dated and only focused on whole milk, but even back then, they were aware of the correlation between storage temperature and shelf-life (Misty & Kosikowski, 1983).
Surveys of consumers in the US have shown a desire for open date labeling. There continues to be confusion between sell-by date-the date manufacturers determine the food can be sold and still have quality of manufacture, use-by date-the date determined by manufacturer as the time by which the product should be consumed, and best-by, best if used, best if used before dates are those that the product should be consumed for ideal quality.
In addition, they also include a statement about use or freeze by dates. This, however, doesn’t apply to liquid milk. That has an additionally required labeling of keep refrigerated. Regulatory frameworks for date labeling vary considerably around the world. Some states in the US impose fines on those who sell food after the expiration date. There are certain perishable products with a short self-life for which time and temperature are not adequately controlled. They can pose a significant safety risk; especially for vulnerable populations. This study mentions the need for consumers to be educated and uniformity in date labeling. In addition, social media actions and smartphone technologies could be used at home to help consumers understand dates on products for more efficient use of left-overs (Newsome et al, 2014).
Failing to keep perishable food in desired temperature range can stimulate the growth of pathogens. Once a product like milk arrives at the retailer, perishable food is generally placed in a display. This is when time-temperature measurements indicate the display cabinets do not keep the product at the proper temperature. Variability of temperature at different locations within a shipment can be significant. Inventory management systems based on time-temperature measurement should start at the pallet.
The cold chain is a necessary component of societies system for delivering food to consumers. The cold chain is an extensive and complex topic and a single article cannot provide a complete overview. However, there continues to be a need for collaboration with the scientific communities in order to keep consumers safe. The examination of the cold chain also helps to decrease spoilage from spores contained in the pasteurized milk. The partnership between science and other researchers will go a long way for sustainable cold chain improvement (Mercier et al, 2017).
This study was done to provide a better understanding of whether the choice of organic milk versus conventional milk was influenced by attitudes or social media. Awareness of the change in consumers’ choice of organic milk rather than conventional milk has caused concern from the dairy industry. According to the author, from 2015-2016 conventional milk sales decreased by 0.4% while organic milk saw an increase in sales by 2.4%; indicating an increase in general media serge in providing information about how ‘bad’ conventional milk was for the consumer.
The organic good craze has expanded globally. Many people choose to drink soy, almond or other plant-based milk because of that craze while a small group drinks them because of a medical condition of lactose intolerance. But the problem is not all plant-based milk contains the same nutrition that conventional milk has.
This study showed that if people were not given enough information they tended to view conventional milk like whatever the current media view was. In this study, the researcher sought to determine the best methods for professional communication to educate people about what they are seeing when reading an organic product label. It was also determined that there were three major groups of respondents to her survey; urban, suburban, and rural. Suburban and rural groups felt they had a better level of understanding of the pros & cons of organic milk versus conventional milk. In addition, the researcher acknowledged the need for further research into this by taking a closer look at the age ranges of the people. It was felt that older respondents may have answered the questions differently than younger ones (Wickstrom, 2017).
Microbial spoilage is a key component of food loss and can occur in products that have been heat-treated and are stored at refrigerated temperatures such as liquid milk. And while microbial spoilage can occur due to post-processing contamination these problems have been addressed by improved sanitation strategies. Spore formations have proved to be a bit more of a challenge. These types of organisms can survive many of the pasteurization heat treatments used to preserve foods and then germinate and grow during refrigerated storage. Consequently, it is very important for a way to control this outgrowth in order to prolong shelf-life of liquid milk.
There are many factors including initial spore concentration in raw milk, spore former frequency in raw milk and their corresponding growth rates can influence the ultimate shelf-life of liquid milk. This study characterized psychio-tolerant spore-former growth patterns and subsequently developed a predictive model to estimate the concentration of psychio-tolerant spore formers in liquid milk over its shelf-life. The study also showed a foundation for the development of improved models that can be used to predict liquid milk shelf-life and shelf-life extension strategies. In addition, they found a storage temperature of 4℃(39.2℉) helped to reduce the number of psychio-tolerant spore formers. Lowering the temp from 6℃ to 4℃ led to an extension of average shelf-life by nine days (Buehler et al, 2018).
Buehler, A.; Martin, N.; Boor, K.; Wiedman, M. (2018). Psychrotolerant spore former growth characterization for the development of dairy spoilage predictive model. Journal of Dairy Science,101(8). American Dairy Science Association. https://doi.org/10.3168/jds.2018-14501
Mercier, S.; Villeneuve, S.; Mondor, N. and Uysal, I. (2017). Time-Temperature Management along the food cold chain: A review of recent developments. Her Majesty the Queen in Right of Canada, Journal of Food Science. https://doi.org/10.1111/1541-4337.12269
Mistry, V.V. & Kosikowski, F.V. (1983). Use of Time-Temperature Indicators as Quality Control Devices for Market Milk. Journal of Food Protection, 46(1). International Association of Food Science. http://foodprotection.com/toc/food/46/1
Newsome, R. et al. (2014). Application and perceptions of date labeling of food. Comprehensive Reviews in Food Science and Food Safety, 13(4). Institute of Food Technology. Doi:10.1111/1541-4337.12086
Wickstrom, A.E. (2017). Environmental factors of attitude formation toward organic and conventional mile: A study of interpersonal networks and interrelationships of milk consumers in CA. Retrieved August 27, 2018 from https://etd.ohiolink.edu/