Vacuum fryer

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Vacuum deep fryers are industrial systems for deep-frying food such as potato chips under a greatly reduced air pressure ( rough vacuum ) of approx. 100 mbar at reduced temperatures (approx. 125 ° C compared to 170 ° C in atmospheric deep fryers ).

Due to the vacuum, the boiling point of the water contained in the food is greatly reduced, so even at relatively low temperatures, water vapor flows against the penetrating fat, which significantly reduces the fat content of the deep-fried food - for example with potato chips. B. from 35% to 17%. Due to the lower temperatures, the acrylamide content of the deep-fried food also drops significantly, in laboratory tests by up to 94%.

The lower frying temperature and the reduced boiling point of the water also help to maintain the natural color and taste of the raw product and make it possible to deep-fry foods that are black and inedible at higher temperatures due to their sugar content or too much due to too little dry matter Would absorb fat. Examples are carrot and beetroot chips . Unrefined vegetable oils with a low smoke point can also be used. Since, in addition to the deep-frying temperature and the deep-frying time, the pressure in the vacuum fryer can also be varied, there is also greater freedom in product development.

Loss of taste can result from the temperature-related, weaker Maillard reaction . Vacuum-fried food is less browned and therefore contains fewer aromatic roasted substances (such as melanoidins ) than conventionally fried food.

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In batch mode working Vakuumfritteusen are mainly in Southeast Asia ( China and Indonesia used) for the production of fruit chips. These machines are only suitable for small production quantities. However, continuously operating vacuum fryers are required for industrial mass production. The first models were developed in the 1960s in order to be able to process the long-stored potatoes from the previous year into potato chips in spring and summer .

Continuously operating vacuum fryers have a steel tank with locks and a connected vacuum pump . The raw product is fed through a rotary valve . Inside the tank, it gets into the baking pan and is then transported by a conveyor belt to the exit lock, which is also connected to the vacuum pump.

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  1. ↑ a b Food aktuell ( Memento of the original from September 3, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Colored chips from the vacuum fryer . @1@ 2Template: Webachiv / IABot / www.foodaktuell.ch
  2. ↑ C. Granda, RG Moreira, SE Tichy: Reduction of Acrylamide Formation in Potato Chips by Low-temperature Vacuum Frying. In: Journal of Food Science. Vol. 69, No. 8, 2004, ISSN  0022-1147 , pp. E405-E411, doi : 10.1111 / j.1365-2621.2004.tb09903.x .

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