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Why does traditional food cooked high in the Swiss Alps taste so good?
To understand whether there is more to the ‘legends’ of mountain cooking than clean air and stunning scenery, scientists from the Nestlé Research Center (NRC) in Lausanne, Switzerland travelled to the world’s highest revolving restaurant – the ThreeSixty in Saas-Fee – for a day’s cooking at high altitude (3600m). Back in the lab (833m), they repeated the cooking process and compared the results. Their verdict – food cooked at high altitude does indeed taste better. The question now was – why?
Low pressure cooking
Atmospheric pressure is lower at altitude, and the lower the pressure, the lower the temperature at which water boils (for example, at 3600m water boils at just 85°C). Could the team scientifically prove that low-pressure cooking has an effect on the way food tastes, and would those findings be backed up by a panel of professional flavour experts?
There are two types of low-pressure cooking: sous vide, where the food is vacuum-sealed in plastic pouches and immersed in water at 65-85°C, and cook vide, which involves reducing the pressure in the cooking vessel using a vacuum pump. While research has been carried out into the texture properties of foods cooked using these methods, the potential impact of low-pressure boiling on its flavour profile has been less studied.
Proving the myth
“Flavour is a key driver of food acceptance and consumer preference”, explains Dr. 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 (cook vide) and ambient pressure. The results were then analysed 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 the culinary quality and molecular and sensory profile of the preparations.”
The scientists measured the pH, weight, solid and liquid losses during cooking, and carried out analyses of volatile and non-volatile compounds (aroma molecules, organic acids, carbohydrates and amino acids). The results were then correlated with the findings of an expert panel of tasters, evaluating such characteristics as overall intensity, saltiness, sweetness and the individual carrot, leek and celery/savoury notes of each sample.
Low pressure means better aroma
The scientists found that low-pressure cooking reduces food weight loss and therefore increases the yield of vegetables. It also leads to significantly richer broths in terms of amino acids, carbohydrates and organic acids, enhancing their non-volatile, volatile and sensory profiles. 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 low-pressure boiling might be used to enhance the flavour profile of culinary preparations by preserving the most fragile aroma compounds, thereby increasing consumer preference. This preservation might also extend to any thermally sensitive compounds such as vitamins, and as such, could potentially be used to improve the nutrient quality of food.
Nestlé is evaluating further how low-pressure cooking can be used to deliver more intense vegetable flavour notes in liquid products and as such, preserve the flavour potential of vegetables during processing.
Source: Nestle
Low Pressure (Vacuum) Cooking with Gastrovac
Gastrovac sucks the moisture out of food so it sponges up all the wine/marinade when the vacuum seal is broken.
Think of the Gastrovac as a crock pot, vacuum pump and heating plate in one.
Suspend your food–pear slices, for example–in a basket above a flavorful liquid, such as wine broth. Seal the machine, and hit a button to turn the cooking chamber into a vacuum.
The low-pressure environment pulls all the air out of the food, compressing it like a squished sponge. Near the end of their cooking, drop the pears into the broth and restore the pressure.
The liquid rushes into the cells, infusing the fruit with an intense wine flavor. And no oxygen means no oxidation–so instead of turning brown, fruit comes out as brightly colored as it was when first sliced.
Read more ….
Gastovac – The vacuum revolution …..
Today’s Comic
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Filed under: Food | Tagged: Low Pressure Cooking, Vacuum Cooking | Comments Off on Low Pressure Cooking May Enhance Flavors, Colours, Aromas