12 Feb 2015 Low pressure cooking may enhance flavours, colours, aromas

A study published in the Journal of Agricultural and Food Chemistry shows that cooking food at high altitude, where pressure is lower, may intensify the flavours, colours, and aroma, as well as potentially improve the nutrient quality of food. [Does this mean the food in Jo’burg – 1 753m – is better than Cape Town?! Ed]

A group of scientists from the Nestlé Research Center (NRC) in Lausanne, Switzerland, traveled to the world’s highest revolving restaurant — the ThreeSixty in Saas-Fee, Switzerland (pictured) — for a day’s cooking at high altitude, some 3 600 m above sea level. Back in the lab, at 833m above sea level, they repeated the cooking process and scientifically compared the results.

They prepared three identical recipes for vegetable broths, one cooked high in the mountains, and two others in the lab—one at ordinary pressure and the other at high pressure — and discovered that the recipe prepared at the restaurant had a very different flavour profile.

“Flavour is a key driver of food acceptance and consumer preference,” said Candice Smarrito, the NRC scientist who led the study. “So we prepared vegetable broths consisting of exactly the same quantities of turnip, carrot, leek, and celeriac cooked at high, low, and ambient pressure. The results were then analyzed both in the laboratory using a range of analytical processes, and by a panel of tasting experts to see how the different combinations of pressures and cooking times impacted on the culinary quality and molecular and sensory profile of the preparations.”

The lower boiling point of water at high altitude and low pressure allows food to cook more gently, at a lower temperature. At 3 600 m, for example, water boils at just 85°C. According to the Nestlé scientists, this process maintains the food’s natural amino acids, carbohydrates, and organic acids, as well as volatile compounds, such as aromas. Having these elements preserved in the components of a finished dish makes the flavours, colours, and aromas more intense, without the addition of a single flavour enhancer or additive, or even salt.
In particular, the team noticed an enhancement of sulphur volatile compounds when boiling at lower pressure, which correlates with a greater leek aroma. In this way, the researchers established that imitating the conditions of mountain cooking through low-pressure boiling might be used to enhance the flavour profile of culinary preparations.

Journal Reference: http://pubs.acs.org/doi/abs/10.1021/jf506173m