A new study has discovered the ideal cooking time and amount of salt to make perfect spaghetti.
Whatever your preference, al dente or very soft, achieving perfection in a dough at home can be a challenge. Many of us have already had the dough to crumble into a beige mush, especially in the case of gluten-free options.
Then, how much water and salt are they really necessary, and how long to cook for best results? Furthermore, how should we adjust the cooking process when using gluten-free dough? A recent publication in the journal Food Hydrocolloids provided some answers by revealing the physics behind the cooking process.
Using the Diamond Light Source, the UK’s national synchrotron (a circular particle accelerator), the authors studied X-ray scattering in the mass (at low angles) to unveil its internal structure. They then went to Isis and the Laue-Langevin Institute, neutron facilities in the United Kingdom and France, and used neutrons (which make up the atomic nucleus together with protons) to elucidate the microstructure of common and gluten-free spaghetti under different cooking conditions.
Study shows how the hidden structure of dough changes during baking and why gluten-free versions behave so differently.
The setup made it possible to investigate the structure of starch and gluten inside the spaghetti on tiny scales, ranging from tens to thousands of times the radius of an atom. In this way, you can compare the transformation that occurs in regular pasta and gluten-free pasta while they are cooked under different conditions, such as prolonged cooking or without salt.
The experiments allowed us to “see” different components of the dough separately. By mixing normal water and “heavy water” (which contains an isotope called deuterium), it was possible to make gluten or starch invisible to the neutron beam. In this way, the authors were able to isolate each structure individually and understand the effects of starch and gluten during cooking.
The power of gluten and salt
The study reveals that, in traditional noodles, gluten acts as a strong structure that keeps starch granules in place even during cooking, giving firmness and slow digestion to the dough. In gluten-free noodles, the starch granules swell and collapse more easily, which explains the soft texture and faster breakage observed when these types of noodles are cooked in less than ideal conditions.
The effect of salt in the cooking water on the structure of the dough was also investigated. It has been found that salt not only improves the flavor of pasta, but also strongly affects the microstructure of the spaghetti. When traditional pasta is cooked in salted water, the gluten maintains its structure and the starch granules suffer less deterioration during cooking.
So how much salt should we add to preserve the microscopic structure of the dough? The study revealed that the ideal salt level is seven grams per liter of waterrequiring more water for larger quantities of dough. The dough must be cooked for ten or eleven minutesin the case of traditional pasta and the gluten-free alternative, respectively. In contrast, when the salt concentration was doubled, the internal order broke down more quickly and the structure inside the starch granules was significantly altered by the cooking process.
In gluten-free dough, the situation was different due to the lack of gluten protection. Even small amounts of salt were unable to compensate for the absence of gluten. The artificial compounds in processed starches, used by companies to replace gluten, degraded quickly. The most extreme example of this degradation occurred when gluten-free spaghetti was cooked for too long, for example 13 minutes instead of 11, and in very salty water.
The main conclusion was, therefore, that the gluten-free dough is structurally more fragile and less tolerant of prolonged cooking and inadequate amounts of salt.
Improving gluten-free alternatives
Understanding the structure of dough on very small scales, invisible even under a microscope, will help in the development of best gluten free foods. In particular, the hope is to obtain gluten-free alternatives that are more resistant to inadequate cooking conditions and with a texture more similar to traditional spaghetti.
Regular wheat pasta has a low glycemic index because gluten delays the breakdown of starch granules during digestion. Gluten-free dough, made from rice and corn flour, generally does not have this structure, which means that the sugars can be released more quickly. With neutron scattering, food scientists can now identify which ingredients and cooking conditions best recreate the structure of gluten.
This is also a story about how cutting-edge experimental tools, used primarily for fundamental research, are transforming food research. Neutron scattering has played a key role in advancing our understanding of magnetic materials, batteries, polymers and proteins. Now, it’s also helping us explain how everyday foods behave on a microscopic level.
