By Cole Burgess

As the holidays rapidly approach, the number of cooking and baking shows that I watch exponentially increases. Although I remain an average or below-average cook, my knowledge of innovative cooking techniques expands. Currently, my favorite technique that chefs use is termed ‘molecular gastronomy.’ This technique characterizes chefs who explore food presentation and eating experiences using non-traditional delivery methods. Molecular gastronomy sits at the crossroads of chefs and food scientists. Both groups share an interest in the optimization of eating and drinking vessels that can deliver flavor to receptors dispersed across the tongue¹. Although the age-old tongue map, which depicts distinct regions of the tongue that perceive flavor, is no longer regarded as accurate, some areas of the mouth have been correlated with a higher density of taste receptors. Within the mouth there are receptors for sweet, savory, umami, sour, and bitter; each receptor binds to a different compound of food: sweet receptors bind to carbohydrates in sugars and sweeteners, savory receptors bind to sodium and potassium ions, umami receptors bind to amino acids in proteins, sour receptors bind to acids, and bitter receptors bind to plant compounds such as alkaloids². After receptor binding by the substrate (i.e., sugar) the receptor leads to signal transduction and cell-cell signaling that ultimately results in your perception of taste.

One facet of molecular gastronomy aims to alter food perceptions to achieve different eating experiences. For example, the ‘pop’ of biting into caviar elicits a different feeling than that of drinking juice. Combining these two sensations results in a new experience, whether that experience is pleasurable or not is for the taster to decide. Texture is a critical part of food consumption and molecular gastronomists aim to elevate traditional flavors and textures into new environments to progress food evolution. In this article, I will focus on the ‘packaging of taste’ using flavored caviar and fruit spaghetti as examples. Taste or the perception of flavor can be associated with its delivery vessel. For example, mango juice may be associated with glass, whereas the mango itself is thought of as a fruit with a defined texture. These vessels provide different textures to the mouth; the juice is a liquid that coats the mouth when gulped, contrasted against the whole fruit that provides a small amount of juice amongst the resistance it requires to chew through it. Both of these experiences are in the context of mango flavor, but they are delivered in traditional contexts, or what I’ll refer to as the normal ‘packaging of taste’ for a mango. Two alternative delivery vessels for mango are fruit caviar and fruit spaghetti; these two ‘packages’ provide the same flavors as mango juice and mango fruit, but in an entirely new context.

Creating a juice sphere, or juice caviar (Figure 1), requires relatively few ingredients, though the time required is much longer. Food scientists and chefs use clever tricks involving vacuum pressure to skip the lengthy ‘setting’ times in the spherification process. The juice sphere has a gel layer surrounding it, similar to caviar, with a liquid center that results in a ‘pop’ of flavor once the gel layer is broken. Preparing a juice sphere requires a liquid of choice, sodium alginate, and calcium gluconate. Alginate is a polysaccharide, a carbohydrate made of multiple simple sugar chains, that can be extracted from seaweed. Different species of seaweed produce alginate of various lengths and strengths, with some capable of forming gels that resist nearly 300 times their weight³. The sodium alginate used in the spherification process cannot form a gel on its own and must react with another compound to polymerize. Polymerization is the process in which simple molecules chemically bond to form a larger, more complex structure. In this instance, the alginate starts as smaller carbohydrate chains but polymerizes to form a larger mesh-like structure. The addition of calcium gluconate to the solution leads to the replacement of sodium ions with calcium ions, leading to the polymerization of the alginate to create a gel⁵. In the juice sphere recipe, the juice is mixed with calcium gluconate before interaction with a water-sodium alginate bath. To achieve the sphere shape, a rounded teaspoon or tablespoon can be used to transfer the juice with calcium gluconate into the sodium alginate bath (Figure 1). Once the two reagents are introduced, the polymerization process begins, forming a thin gel layer around the juice sphere. Incubation time matters, as a short interaction period, will result in a thin gel layer that snaps similar to caviar, while prolonged incubation can lead to a jelly-like bead. Gastronomists have advanced spherification beyond juices, with some even using oyster soup⁴.

Another intriguing technique is the use of fruits to make spaghetti (Figure 2), whether it be as a dessert or a renovated take on a classic pasta dish. Traditional wheat pasta is not the only flavor spaghetti can have, as the recent pasta revolution has produced the use of zucchini, squash, and other vegetables as noodles or pasta replacements. Molecular gastronomists have taken this revolution even further to include fruits as a base for pasta formation. Fruit spaghetti is relatively simple in comparison with spherification, as it involves the use of only the desired fruit, sugar, and agar. Agar is a common ingredient used in research labs to form gels and bacterial plates. To prepare the fruit spaghetti, the fruit and sugar are pureed to ensure no large chunks remain, which would harm the formation of the spaghetti. The puree is then mixed with agar and brought to a boil. Once the mixture is boiled, it can be pushed into a tube to take the shape of spaghetti. The tube is then rapidly cooled to allow the agar and fruit to solidify before extrusion onto a plate. Through textural alteration, fruit can be presented in many interesting ways, as seen in spheres and spaghetti.

Molecular gastronomists are pushing the envelope of food evolution, by incorporating flavors and textures that aren’t associated with classic techniques. Juice caviar and fruit spaghetti are just two of the creative techniques chefs now use to enhance the food experience of patrons. Whether or not these innovations are enjoyable to the palate remains to be seen, but the evolution continues regardless.

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References:

1. Yek, G. S., and K. Struwe (2008). “Deconstructing Molecular Gastronomy.” Food Technology: 34-43.
2. Schifferstein, H.N.J., B.M. Kudrowitz, and C. Breuer, Food Perception and Aesthetics – Linking Sensory Science to Culinary Practice. Journal of Culinary Science & Technology, 2020: p. 1-43.
3. Alginate: https://dalchem.com.au/how-to/what-is-alginate#:~:text=Alginate%2C%20also%20called%20Alginic%20acid,the%20cells%20as%20a%20polysaccharide.
4. Oyster Soup Spherification Recipe: https://kitchen-theory.com/spherification-of-oyster-soup/
5. Alginates in Food: http://culinaryphysics.blogspot.com/2014/09/alginates-in-food-sodium-alginate-uses-in-food.html#gsc.tab=0
6. Mango Sphere Image: https://www.gastrosenses.com/blog/mango-spheres/
7. Fruit Spaghetti Recipe: https://www.youtube.com/watch?v=4nPMLNaBWNI