Chapter 55

Cooling things Down: Fat determination of ice cream according to Weibull-Stoldt

📂 Case overview: After the detective’s last workshop that involved eating and analyzing some of the world’s hottest chilis, the detectives cool off and focus their attention on something they all love – ice cream! A new company is ramping up its operation and needs to determine the fat content of its ice cream to ensure compliance. The detectives discuss the complications that ice cream may cause and offer a solution that adheres to stringent regulations.

The detectives reconvene after their last case involving the analysis of capsaicin in chilis . Eggcule and Cornlumbo are still bragging about how they ate and survived one of the world’s hottest chilis. Both detectives seem to have forgotten how much they struggled and talked as if they had effortlessly handled the task. As Holmes enters the office, they are still having a heated debate about who struggled the most, and he notices how annoyed Miss Mapple and Nancy Beef seem, having had to listen to the bickering all morning. Luckily Holmes has a case for the detectives that will cool everyone down. “Attention detectives,” shouts Holmes, which immediately brings an end to the bickering. He then describes the latest case to the detectives that will involve ice cream. Immediately the atmosphere in the room changes. The weather has been sweltering this year, and the detectives needed to cool off both figuratively and literally. As it was the case with beer , each of the detectives had their own opinion on what made the best ice cream.

Shallot Holmes and Miss Mapple fondly remembered the ice cream vans that would arrive every year in the British summertime, playing a merry jingle that would get the attention of all the children who would stop whatever it was that they were doing and run straight to the van, via their parents who would inevitably have to cough up some coins or face some very disgruntled children. The American detectives Cornlumbo and Nancy Beef recalled the joy of visiting restaurants and ordering ice cream sundaes layered with syrup, whipped cream, and all sorts of weird and wonderful toppings. “Ooh, that sounds like a knickerbocker glory,” says Miss Mapple. Eggcule Poirot looks confused at this talk of sundaes and knickerbocker glories and says that the Belgians like their ice cream served in a waffle cone, as you can never have too much waffle! Holmes is thrilled to see all the detectives looking so happy and enthusiastic and says, “Ok, detectives, we could obviously talk about ice cream for the rest of the day, but we have a case to solve. Let’s head to the client’s processing facility, and if we’re lucky, we may get to ‘analyze’ some of the produce a few samples ourselves.”

On arriving at the ice cream manufacturers, the detectives all feel like children again; there is a huge display at the entrance of all the ice creams made by the company. There is vanilla, strawberry, chocolate, pistachio and fig, mascarpone, and cherry; they even had speculoos, which made Eggcule positively giddy. The client welcomes the detectives and asks if they would like to try any ice cream, but before anyone can answer, Holmes says they will only try the ice cream if they successfully solve the case. Cornlumbo looks as if he’s just been told the world is about to end and immediately becomes very interested in the details of the case. The client explains to the group that they have been making ice cream as a passion for years, but only for their own pleasure and to share with friends. On the advice of their friends, the client has decided to create and sell to the public, but this decision has bought about the need for regulatory compliance, something the client has no experience with. Cornlumbo, keen to try the ice creams, immediately looks up the regulations that apply to the manufacture and sale of ice cream. “ISO 8262-2 / IDF 124-2,” shouts Cornlumbo. The client looks positively baffled and confused, and before Cornlumbo gets too ahead of himself, Holmes offers the client an explanation. “ISO stands for the International Organization for Standardization and is an independent NGO that develops standards to ensure the safety and quality of products and services. The IDF is the International Dairy Federation that represents the interests of dairy stakeholders and promotes standards and guidelines relating to dairy products. To sell your products, you must adhere to the guidelines of the ISO and IDF to ensure regulatory compliance. For certain products, you must also adhere to specific reference methods that are accepted by the relevant regulatory bodies,” explains Holmes.

“you must adhere to the guidelines of the ISO and IDF to ensure regulatory compliance. Certain products must also adhere to specific reference methods that are accepted by the relevant regulatory bodies”

Cornlumbo goes on to explain that the fat content of the client’s ice cream must be determined according to the Weibull-Stoldt method. Again, the client looks confused, so Cornlumbo breaks it down. “There are several means of determining fat content , usually by means of solid-liquid extraction. The principle of extraction is relatively simple, and it’s a fundamental process in analytical chemistry used to separate compounds based on their relative solubilities. Several methods of extraction use solvents to dissolve and isolate specific compounds from a mixture. Different methods take advantage of different chemical processes, such as Soxhlet extraction and Hot extraction, which use heat to speed up the process, or Pressurized LiquidSolvent Extraction , which uses pressure and heat to enhance the process further. The Weibull-Stoldt method I mentioned applies to the analysis of ice cream and involves an acid hydrolysis step to be performed before the Soxhlet extraction,” explains Cornlumbo. “So, to determine how much fat is in my ice cream, I must first extract the fat,” says the client. “Exactly,” says Cornlumbo. “So, what is this acid hydrolysis step you speak of? I thought the extraction method was able to isolate compounds,” asks the client. Cornlumbo explains that an additional step is required for certain products, such as ice cream because surface tension forces colloidal components to surround the fat droplets in certain dairy products. These fats must be released from the matrix to be subsequently determined. The bonds holding lipid and non-lipid components must be broken down before extraction, and hydrolysis breaks down the encasing proteins releasing the physically enclosed fats. The Weibull-Stoldt method ensures that not only soluble fats are determined but also those that are bound to proteins. After Cornlumbo’s explanation, the client seemed very content with his understanding of the regulations that apply to his business and much happier about his knowledge of the chemical processes involved in determining the constituents of his produce.

“The Weibull-Stoldt method involves an acid hydrolysis step before the Soxhlet extraction. The bonds holding lipid and non-lipid components must be broken down before extraction, and hydrolysis breaks down the encasing proteins releasing the physically enclosed fats”

Holmes is also pleased with Cornlumbo’s work and is again amazed at what he is capable of when there is food at stake. “I suppose there is only one thing left,” says Holmes. Cornlumbo immediately looks panicked and starts racking his brain, trying to figure out what he has forgotten. Holmes tells Cornlumbo to relax as the only thing left to do is try the ice cream! The client cannot wait to get the detective’s opinion and takes them over to the ice cream stand and lets the detectives have their fill. Each of the detectives tries small amounts of the ice cream and gives their opinion, apart from Cornlumbo, who dives headfirst into the first ice cream he sees, filling his mouth to the brim, before getting an attack of brain freeze! Holmes explains that brain freeze occurs when the body senses sudden extreme cold and blood vessels throughout the head expand to let extra blood into the area for warmth; however, nobody hears him as they are too busy laughing at Cornlumbo’s misfortune.