Gut Instincts: The Secret to Total Fat Determination

In the office, Shallot Holmes explains the details of a case from NutriNibbles, a company that produces healthy snacks. An independent testing lab contacted NutriNibbles about the declared fat content of its latest line of products. “The independent lab results suggest the fat content in their new MightyMunchy protein bars is higher than declared. Hazel Nuttington, the CEO, cannot fathom why the discrepancy exists. She ordered the snacks to be tested again, but their internal results continually showed lower values than the results provided by the independent lab. For some reason, their extraction methods do not allow them to extract all the fat in their protein bars. She has asked if we can get to the bottom of the mystery and fix the discrepancy in the results,” says Holmes.

“Do you have any of these MightyMunchy protein bars on you? As I have discovered the fastest possible fat extraction method to date, guaranteed to extract every milligram of fat from the sample, it takes less than 5 seconds and doesn’t require any lab equipment!” declares Cornlumbo. Nancy Beef crosses her arms, looking skeptical. “Oh really? Care to demonstrate?” Cornlumbo nods. “Alright, just hand me a sample, and I’ll show you.” Shallot Holmes reaches into his bag, removes a NutriNibbles bar, and tosses it to Cornlumbo, who catches it and swiftly unwraps it. Without hesitation, Cornlumbo devours the bar in a few quick bites, licking the remnants from his fingers. He leans back with a satisfied smile. “There you go. Fat extraction complete!” he declares, patting his stomach. “Results stored for future analysis!” Nancy rolls her eyes. “I see you still prefer the ‘internal digestion’ method.” Cornlumbo shrugs and chuckles, “Sometimes, old-school techniques are the best.” 

The detectives roll their eyes in unison, apart from Shallot Holmes, who appears deep in thought. “You know what, Cornlumbo, I think you might be onto something. Why don’t you visit the client and be sure to explain your internal digestion method? As you said yourself, your method can extract every milligram of fat from the sample, and that is exactly what the client needs to achieve in their analysis,” says Holmes. 

Suddenly, Cornlumbo looks worried, and the detectives look very confused; how could sending Cornlumbo to gobble all their MightyMunchy bars possibly help? Miss Mapple, who always calls out Cornlumbo for his pranks and antics, thinks that Holmes may want to humiliate Cornlumbo for continually messing around.

“Umm, but, I, err, you really want me to go to the client?” asks Cornlumbo. “Yes, and be sure to explain to them how your fantastic method works,” says Holmes. “But, I was only jok..” “Now! Cornlumbo, go!” shouts Holmes before Cornlumbo can finish his sentence.

How can digestion be the answer to fat extraction?

Cornlumbo arrives at the NutriNibbles headquarters, a vast, imposing building on a large industrial estate. Hazel Nuttington is waiting in the reception area “Ah, you must be Cornlumbo, one of the famous food detectives! We are so happy to have an expert of your caliber to show us how to improve our methods. Let me give you a quick tour of our labs, and then we’ll head to our conference room, where the entire company is waiting to hear about your extraction method. Shallot Holmes told me you have a fantastic technique you want to share with us all,” says Hazel excitedly. Cornlumbo is now dripping with sweat, and his heart races as he is shown around the company’s lab, full of modern extraction equipment. “As you can see, we have spared no expense, and our extraction equipment can perform Soxhlet, hot extraction, and Twisselmann in one unit; just through that door is our conference room. I’ll go first and introduce you,” says Hazel before heading into the conference room. 

Cornlumbo freezes and begins to panic “What have I done? I’m such a fool… No wonder Holmes has sent me here to be humiliated…” he thinks. Meanwhile, in the conference center, Hazel begins her introduction. “Thank you, everyone, for attending; it has been a while since all 238 employees of NutriNibbles have gathered in one space…

“238 employees!!!! 238.. I’m going to look such a fool!!!” thinks Cornlubo.

“Today, we have an extraordinary guest from the food detectives, a protegee of Shallot Holmes himself, here to show us a technique he claims can extract every milligram of fat from our new line of MightyMunchy nutrition bars, a technique that will solve the discrepancies we have been having with our declared fat content. Without further ado, please give a warm round of applause to… Cornlumbo!” says Hazel before taking her seat.

Almost paralyzed with fear, Cornlumbo walks through the conference room doors onto the stage and looks upon the vast crowd gathered to see him. On the stage is a table with the complete range of MightyMuchy nutrition bars. 

“I will now show you how to extract all of the fat from this nutrition bar,” says Cornlumbo as he approaches the table, picks up one of the bars, and unwraps it. The audience falls silent and waits in anticipation. Cornlumbo begins to shake, knowing how ridiculous he is about to look in front of the crowd. He considers running from the stage and heading for the hills. Cornlumbo looks at the MightyMunchy bar in his hand and remembers just how delicious it was. His instinct to run is replaced with his usual instinct to eat tasty food, and without hesitation, he grabs the bar and rams it in his mouth; his eyes close as he begins to enjoy the delicious flavors, and for the briefest of moments, he forgets where he is. He grabs another bar, then another, and devours the entire MightyMunchy range until no bars are left. As he finishes the last bar, he opens his eyes and remembers where he is. 

All 238 employees stare at Cornlumbo in a state of confused horror as he mumbles the words “Extraction complete.”

Silence. 

Cornlumbo stands paralyzed, looking out into the expectant crowd.

Standing motionless, he remembers what Holmes said before leaving the office: ‘Be sure to explain your internal digestion method. As you said yourself, your method can extract every milligram of fat from the sample’. 

Cornlumbo looks into the crowd and does his best to explain himself. “Now that I have eaten all the bars, they will be internally digested,” says Cornlumbo, who begins to talk without thinking as his nerves kick in. “When the food enters my stomach, it is mixed with gastric juices that contain hydrochloric acid and digestive enzymes. This acidic environment denatures and breaks down proteins, unraveling their complex structures, making the nutrients available for absorption.” 

As Cornlumbo explains the process, he suddenly realizes what Holmes must have realized – his crazy method did contain the solution to the client’s problem. Cornlumbo’s nerves evaporate, and his confidence builds as he continues his explanation. 

“Many foods, like your MightyMunchy bars, contain fat embedded within complex structures, such as proteins and carbohydrates. These lipids are not free but bound to other molecules like glycoproteins and glycolipids. Performing extraction on such foods will only detect the free fats but not these bound fats. Therefore, you need a method to release these bound lipids before performing your extraction. Obviously, digesting the food in my stomach, although effective, is not practical as you cannot retrieve the samples for further analysis. You need a Cornlumbo’s stomach machine to perform this step, a hydrolysis unit. Performing acid hydrolysis as a part of your sample preparation will release the bound fats that can subsequently be determined using the extraction methods you are all familiar with. By including this step in your process, I’m sure you will eliminate the discrepancies you have been getting with your results,” explains Cornlumbo.

As soon as he finishes talking, the entire audience erupts into a massive round of applause, and everyone giggles and laughs at Cornlumbo’s demonstration. “Three cheers for Cornlumbo’s stomach,” shouts one employee as the chorus of hip hip hooray begins to a standing ovation.

Before leaving, Cornlumbo outlines the steps required for acid hydrolysis.

How can I perform acid hydrolysis for total fat extraction?

Step one: Sample preparation

• Glass sample tube with frit for filtration.                                                                                                                                             
• Quartz sand                                                                                                                                                                                       
• Celite® 545
• Hydrolysis vessel                                                                                                                                                                             
•  Celite®                                                                                                                                                                                        
• Homogenized food sample                                                                                                                                                       
•  Hydrochloric acid, 4 mol/L

Step two: Acid Digestion

• Lower the hydrolysis vessels into the heating chamber
• The stop cocks are open, and a vacuum is applied for the removal of acidic vapors.
• The sample matrix is decomposed in boiling hydrochloric acid, and fat is released and absorbed by the Celite®
• After 30 minutes, the hydrolysis is complete, and the sample is diluted with 100mL of warm water (50ºC).

Step three: Sample transfer, filtration, and rinsing.

• A powerful vacuum transfers the diluted sample to the glass tube with frit for filtration.
• The mixture is rinsed until neutral.
• Rinsing funnels facilitate the rinsing of the hydrolysis vessels and guarantee quantitative sample transfer to the glass sample tubes.

Step four: Sample drying

• The glass sample tubes are dried in a drying oven and afterward directly placed into the extraction equipment.

Cornlumbo returns to the office, where the detectives are anxiously waiting to hear what happened. “So, Cornlumbo, what did the professionals at NutriNibbles make of your fat extraction technique?” says Miss Mapple. “I’m sure they were all very impressed with your eating abilities,” says Nancy Beef sarcastically. “As it happens, I received a standing ovation. They are going to introduce a Cornlumbo’s stomach machine into their process to assist with future analysis,” says Cornlumbo. Holmes chuckles and gives Cornlumbo a knowing wink as the rest of the detectives sit looking bemused.