Beat the Heat: The Importance of Robust NIR Models in Ice Cream Production
It’s another hot sunny day, and the detectives are in the office discussing what they did over the weekend. Cornlumbo and Eggcule have been arguing over barbequing methods for almost an hour, and Miss Mapple is beginning to lose her patience. “So, what did you get up to over the weekend, Nancy?” asks Miss Mapple at the top of her voice in an attempt to put an end to the bickering. “Well, I went swimming yesterday at the outdoor pool,” says Nancy Beef. “Ooh, that must have been wonderful and a great way to cool down,” Miss Mapple responds. “There’s nothing quite like dive bombing into a pool to cool off!” says Cornlumbo. “Oh, you wouldn’t get away with that; the pool is set up for lane swimming when I go,” says Nancy. “That must be nice, not having to worry about all the children splashing about causing mayhem,” says Miss Mapple, casting an eye at Cornlumbo as she speaks. “Yes, it is wonderful, sometimes. But, yesterday, I got stuck behind a really slow swimmer, and every time I overtook them, they would switch directions, so as soon as I’d reach the end and turn around, I was stuck behind them again,” says Nancy. “Ooh, how insufferable,” remarked Miss Mapple. “I have no luck, as the other day when I went swimming, I had this super-fast swimmer behind me, and I know how annoying it is to be held up, so I swam as fast as I could and got so tired; I had to end my swim after 20 minutes,” says Nancy. “How annoying; you’d think the swimming pool would have lanes to accommodate the variability in swimming speeds,” says Miss Mapple. “You’d think so, wouldn’t you,” says Nancy Beef as Shallot Holmes arrives in the office and notices how hot and bothered everyone looks. “I must say, you all look a little hot under the collar, but I have the perfect case to cool you all down,’ says Holmes, who begins to describe the details of the latest case.
Why would in-house NIR results conflict with external analysis?
The Lickety Split ice cream company is getting inconsistent results from its quality control and nutrient analysis. It needs the assistance of the premier food detective agency to solve the dilemma. “Perhaps they should use on-line NIR spectroscopy analysis to assess every batch, as this might help with the inconsistencies they have been getting – NIR is also super quick, which seems ideal for a company called Lickety Split,” says Miss Mapple. “You’re right, but the company already has an NIR-Online system in place; the readings they initially took corresponded with the results of third-party analysis; however, there are now discrepancies between the data acquired from their NIR-online system and the latest analysis performed externally” explains Holmes. “How strange,” says Nancy Beef. “It reminds me of the case I had in Italy where the pasta producer Poppa Passarelli had inconsistent results due to inconsistencies in his production. The pasta was not a uniform thickness therefore, the results were inconsistent. Perhaps there’s a problem with their production?” says Miss Mapple. “You’re right, Miss Mapple; perhaps you should visit Lickety Split and see if you can get to the bottom of this mystery,” says Holmes, and with that, Miss Mapple makes her way to the client.
Why are robust calibrations critical for dairy production facilities?
Miss Mapple arrives at the facility and begins her investigation. She checks the locations where the NIR probes are placed, investigates the various processing techniques used, and even checks the types of ice cream being analyzed, searching for any inconsistency that may account for the skewed results, but she finds nothing. She then asks the client about the raw materials used. As the client explains the nature of the raw materials, Miss Mapple starts to understand what the problem might be.
Unlike pharmaceutical and chemical companies that work with pure products with minimal variability, the agricultural produce the ice cream facility uses showed high variability. Numerous factors influence the raw ingredients used, such as seasonal differences in fruits and milk from various breeds of cows sourced from various locations. The high variability reminded her of the troubles Nancy Beef was experiencing while swimming. Just as the varying abilities of swimmers caused mayhem in the swimming lanes, the varied nature of the raw materials caused mayhem for the NIR calibrations used to analyze the ice cream. This variation explained why the initial calibrations were fine, but subsequent analysis proved inconsistent.
Miss Mapple asks the client about the samples they had used for their calibrations and finds out that the samples used to calibrate their NIR systems came from one particular batch of ice cream. As time passed, the raw ingredients changed, and the calibrations could not account for these inconsistencies.
How can NIR calibrations be made more robust?
Miss Mapple explains to the client that calibration models are the foundation of NIR spectroscopy. They translate spectral data into meaningful information about the sample composition, but for these models to be effective, they must be robust and capable of handling sample deviations. The client is keen to find out what they can do to improve their calibrations. Miss Mapple says they need to collect a more diverse set of samples that represent all possible variations in raw materials, production processes, and environmental conditions. Also, the chemometrics experts could employ multivariate analysis techniques like Partial Least Squares (PLS) regression to build more robust models that can handle complex data and extract relevant information from the spectral data. Due to all the seasonal changes, it would also be necessary to periodically update the calibration models to include new data and account for any changes in the production process or raw materials. The client is delighted, and together, they set about collecting more samples to improve the calibration models. As a way of thanking Miss Mapple, the client gives her a selection of Lickety Split’s best-selling ice creams to take back to the detectives, ensuring they all keep their cool in the summer months!