Chapter 47

Pasta producer's problems: The detectives educate a client on NIR

📂 Case overview: The detectives help a client with their semolina manufacturing plant. Their instruments do not have the right specification for their needs, and their process has been brought to a standstill. The client, who knows a great deal about their raw materials, lacks in-depth knowledge of the analytical side of the business. Can the detectives get the operation running smoothly again and share their knowledge of NIR to put an end to the pasta producer’s problems? Read on to find out.

The detectives are relaxing after their case involving a blockage in a pressurized speed extractor . Then suddenly, the phone rings, startling Eggcule Poirot, who almost falls from his stool, narrowly escaping a scrambling. Shallot Holmes answers the phone and is greeted by a distressed client. “Is that the food detectives? You must help! My NIR machine has died,” says a very distressed woman. “Died?” says Shallot Holmes, which immediately got the detectives’ attention as they all tried to work out what Holmes was being told. “Yes, died! my NIR machine, I heard an awful scream, and everything ground to a halt”, says the client. “You heard a loud scream?” says Holmes. The detectives, who are only hearing one side of this conversation, are getting curiouser and curiouser. Screaming, death, what on earth is going on? “Heard a scream, dead when you arrived on the scene,” says Holmes making notes as he listened. By now, the detectives are on the edges of their seats; this sounds like the most blood-curdling case they have ever encountered.

The client explained that their NIR instrument had broken, and the operator stopped the process. Holmes calmly tells the client not to worry; the detectives will be over immediately to investigate the problem and find out what caused the NIR machine to ‘die’. The client is relieved and awaits the detective’s arrival. Holmes tells the anxious detectives that nobody has died; the client’s NIR spectroscopy instrument had a fault that caused them to stop their process. He tells the detectives to gather their things as the client is keen to get their manufacturing plant running back to speed. What’s more, the client is based in Italy, a country renowned for its cuisine. The detectives are all very excited, especially Cornlumbo, who is giddy at the thought of all his favorite Italian foods. “Did I ever tell you all how much I love Italian cuisine,” said Cornlumbo. The other detectives chuckle as they are fully aware of how much Cornlumbo loves to eat.

On the train, the detectives discuss NIR to refresh their knowledge of the process. After a lengthy discussion, Holmes asks the detectives to summarise their findings. “Speed,” says Miss Mapple. “Very good, yes, that is one of the main benefits of NIR compared to traditional methods,” says Holmes. “Anything else?” “Non-destructive and environmentally friendly,” says Nancy Beef. “Again, very good, NIR indeed does not require any chemical reagents or solvents, unlike other methods of analysis,” says Holmes. “Is that it? Or are there other factors to consider?” Holmes asked. “Chocolate!” says Cornlumbo. “Chocolate? What are you talking about?” says Holmes incredulously. Cornlumbo had spotted the food and drinks trolley on the train and had involuntarily blurted out ‘chocolate’. Miss Mapple and Nancy Drew chuckled as he now turned red with embarrassment. “A better suggestion would have been multi-component analysis, as NIR can be used to monitor multiple components of a sample simultaneously. That feature would greatly benefit a semolina producer; however, none of our ideas explain why the NIR system would fail. I feel that further investigation is required, but we can all have some chocolate on the way home if we successfully solve this case,” declared Holmes as the train pulled into the station.

Upon arriving at the client’s laboratory, the flustered client greets the detectives. She is keen to show the detectives the facility and show off her produce. The client tells the detectives the word semolina is from the Latin simila meaning ‘flower or flour’. It is obtained by coarsely grinding a cereal, mainly durum wheat, into granules. Cornlumbo says that the semolina used for polenta is made from corn. The client is impressed “That’s right! There is also white semolina made from ground rice, yellow semolina, made from wheat and colored with saffron, and even semolina for kasha, a traditional Russian breakfast porridge made from buckwheat.” The client goes on to explain the process, which involves moistening the grains, grinding, drying, and sieving them. “The final product is so versatile and can be used for soups, garnishes, kinds of pasta, and dishes, such as couscous, tabbouleh, gnocchi, puddings, cakes, custards, and soufflés.” By this point, Cornlumbo is becoming dizzy thinking of all the delicious things that can be made with semolina. “Please tell me more, as I’d love to know how to use semolina in my own cooking,” begs Cornlumbo, but before the client is able to respond, Shallot Holmes reminds the detectives that they have a case to solve. “Oh yes,” says the client. “Let me show you the processing facility”.

The detectives enter the processing facility where the wheat is received and processed. It is noisy and dusty, unlike traditional labs that are sterile, clean, and free from dust and other contaminants. Shallot Holmes looks at the NIR equipment they have installed and thinks he has found the problem. “Can you tell me if this equipment has IP69 certification?” asks Holmes. The client looks puzzled. “I’m not sure I understand what you mean,” she says. Shallot Holmes explains that the IP certification relates to Ingress Protection. The first number relates to protection against dust, which is rated between 0 and 6, with 6 being the highest level of protection with no ingress of dust. The second number is the protection against water ingress; this is rated from 0-9, with 9 being the highest level of protection, ensuring no water ingress even under powerful high-temperature water jets. “I fear that the fine semolina powder you have produced has interfered with your equipment,” says Holmes. “For a facility such as yours, an IP69 rating is essential,” Holmes tells the client about NIR spectroscopy equipment that is designed specifically for processing plants. This equipment is extremely robust and unaffected by temperature and humidity fluctuations and can also be pressure-hosed to meet the highest standards of hygiene. The client is very grateful and asks the detectives for as much advice as possible to ensure the success of her operation. The detectives take turns explaining in detail how NIR can simultaneously monitor moisture, protein, gluten, and ash in her semolina, ensuring quality control and the highest-quality produce. Monitoring moisture is critical for the storage and further processing of semolina. If it is too high, bacteria can form. Ash and protein content are also essential for declaration requirements and regulations.

Having solved the case, Cornlumbo immediately gets back onto the topic of cooking. The client explains that ordinary semolina uses the peripheral part of the grain; however, fine semolina is what is required for pasta. “I now understand the importance of keeping this fine powder out of my NIR equipment,” she says. She explains that a medium or course semolina is used for soups and desserts. Noticing Cornlumbo’s excitement at the mention of dessert, she shares a simple recipe for semolina pudding with the detectives.

Semolina pudding

Get a flameproof casserole dish and add 1 liter of milk containing 150g caster (superfine) sugar, a pinch of salt, and a vanilla pod split in half. Slowly bring to a boil. Mix in 250g of semolina and 75-100g of butter while heating the mixture until all the ingredients have combined into a smooth consistency. This dish is extremely versatile as you could enjoy it as a warm custard or even enjoy it cooled. You can even bake the mixture in a preheated oven. For a creamier pudding, you can add an egg. Eggcule Poirot did not look impressed by this suggestion. The client noticed his horror at the suggestion and went on to make some alternative suggestions. “Variations of semolina pudding are famous throughout the world; the basic dish I have described is so versatile. There is Galaktoboureko, an ottoman recipe that encases the mixture in puff pastry, and Layali Lubnan, ‘Lebanese nights’ that covers the baked pudding in thick cream and pistachios, often also containing rosewater or orange blossom in the mixture. Or there is Suji Ka Halwa, an Indian dish that uses cardamom, saffron, and ghee, the traditionally used Indian clarified butter. There is even a book of roman recipes from the 4th century AD that refers to a semolina dish mixed with almonds, raisins, and raisin wine.

The detectives are fascinated, and their heads are full of exciting potential semolina pudding dishes to try out. They thank the client for sharing her wisdom as she thanks the detectives for sharing theirs. On the way home, Shallot Holmes, true to his word, buys all the detectives some chocolate. Cornlumbo says, “I’m going to take my chocolate home and melt it over a semolina pudding.” The detectives roll their eyes and chuckle as they enjoy their reward for a job well done.