Molecular Gastronomy

1. What is molecular gastronomy?

Culinary arts + science! Food is being prepared in colloidal systems in which ingredients go through physical and chemical changes.

Some cooking methods include:

• Spherification – like the bursting lychee pearls/ popping boba in our bubble tea! Sphere is created when the chemical reaction between sodium alginate mixture dropped into calcium chloride bath forms a thin membrane around the juice, creating the caviar spheres.
  • For effective spherification, the pH level of the juice must be > 3.6 and cannot contain calcium.
  • Spheres are created due to the surface tension when one liquid is dropped into another liquid.
• Reverse spherification – Instead of dropping a sodium alginate mixture into a calcium chloride bath, reverse spherification drops the mixture with calcium content into a sodium alginate mixture. The chemical reaction then forma thin membrane around the juice like in the spherification process.
  • The benefit of using reverse spherification is that it is more versatile than regular spherification and can be made using liquids of high calcium/ alcohol content.
  • Xanthan Gum can be added to thicken the liquid until the appropriate viscosity is obtained.

• Sous vide – slow cooking of food in heated water to retain moisture
• Liquid nitrogen – make ice cream as fresh as possible without incorporating too many chemical ingredients

It is interesting to note that many people are exploring molecular gastronomy concepts at home these days especially with both the sous vide cooking method as well as sperification. These are both concepts I would like to try especially during this season when I’m stuck at home due to COVID-19.

2. Types of colloidal systems include:

1. Sol – Solid dispersed in a liquid (e.g. egg white)
2. Foam – gas in a fluid
   • secret ingredient to creating foam is gelatin!
   • Gelatin is basically collagen protein from animal hides and bones. The protein forms a film around the air bubbles dispersed in the liquid, giving the foam structure and preventing air bubbles from merging into larger bubbles.
   • More gelatin = thicker foam.
   • Surfactants required to keep bubbles away from the liquid, from coalescing to ensure a stable foam.
3. Solid Foam – gas dispersed in a solid (e.g. cake, bread)
4. Gel – liquid dispersed in solid (e.g. curd, cheese, jelly, pudding)
   • starts as a complex fluid (colloids in a liquid)
   • Through Brownian motion, colloids at lower volume fractions can move more freely.  Colloids then condense together, leaving the surrounding void of particles. Attractive forces however, hinder the colloids as they phase separate, bonding them into a network, creating a gel.
   • Gels harden over time because colloids coarsen due to very slow phase separation.
5. Emulsion – stable mixture of drops of immiscible fluid in a second fluid. (e.g. milk, butter, oil in water)
   • There is a need to stabilise the drops of oil in water using a surfactant/emulsifier (surface active molecule) which prevents 2 droplets from joining together.
   • Excess surfactants form aggregates which are called micelles.
   • Emulsions fail with time – where the emulsion loses the drops of the first fluid (oil) in the second (water) due to differing densities. This could happen due to coalescence of the drops of the first liquid or Ostwald Ripening (the transfer of fluid from a smaller drop to a larger drop due to the difference in pressure)
   • Limitation of using emulsifiers is its oil load capacity in which the amount of oil added exceeds the limit of the emulsifiers to maintain proper dispersion, resulting in an unstable emulsion.
6. Solid emulsion – can be created only if one emulsifies enough olive oil that one obtains highly compressed drops which become elastic and solid.

The Future of Food

Why meat is the worst thing in the world?

Meat is no longer just food for the privileged but is easily accessible by most people on a daily basis. However, the production of meat, especially beef, has been deemed to have many negative environmental impacts. 15% of GHG produced is created by meat industry. This is the same percentage as the production of GHG by various forms of transport. Furthermore, a disproportionate amount of nutritional benefits are consumed by humans as compared to the amount of food that the cows consume. For example, in order to produce 1 kg of beef an input of 25 kg of grain and 15,000 L of water is required but only 4% of the proteins and 3% of the calories from the plants in the cow’s feed turn into beef. Therefore, argumentatively, meat does not provide as much nutritional benefits as one would expect.

With greater exposure and knowledge to such negative impacts of meat, one would say that our diet would eventually evolve to reducing the amount of meat consumed and replacing it with lab meat, an innovation from recent years. Another trend would be an increase in the number of vegetarians to reduce the unnecessary strain on resources and negative environmental impacts.

Organic food – a moral and social responsibility?

An increasing number of our privileged have started to make the transition to purchasing organic produce due to belief that the production method is a lot cleaner and therefore, they would also be eating healthier. While a greater amount of antioxidants have been found in organic food, a general summary of other studies have shown that there are only small differences in the overall nutritional values between conventional and organic produce.

More importantly, in organic farming, while more traditional methods of farming are used, both forms of crop productions include the use of pesticides. Therefore, organic produce are not necessarily cleaner than conventional produce.

Finally, in terms of negative environmental contribution, by comparing GHG production, land and energy usage, the general consensus is that both forms of food production are similar in terms of overall negative contribution to our environment.

Therefore, looking to the future, it is crucial to note that what you eat is more important than how it is produced.