DE2905575A1 - PROCESS FOR PEELING FRUIT AND VEGETABLES - Google Patents

Description

PATENT ADVOCATE DR. HANS-GUNTHER EGGERT ₁ DIPLOMCHEMIKEI

S COLOGNE 51, OBERLÄNDER UFER 90 "_, _A _ _" _ _

Cologne, February 13, 1979 No. 2

Aktieselskabet De Danske Spritfabrikker, Raffinaderivej 1o, 23oo Copenhagen S / Denmark

"Process for peeling fruits and vegetables"

909834/0745

Process for peeling fruits and vegetables

The present invention relates to a method for peeling Fruits and vegetables by heating with aqueous alkali.

In the known methods of peeling fruit and vegetables by heating with aqueous alkali, one has sodium hydroxide or potassium hydroxide used as an alkali because it was believed that the strongest possible alkali was necessary to remove the peels. However, the method has significant disadvantages, which can be attributed to the fact that it takes too long a heating time to get one to ensure a satisfactory degree of peeling. For this reason, the method of thermal energy is costly and suitable therefore · only for peeling fruits and vegetables that are cooked anyway and less for peeling fruit and vegetables that must not be cooked or softened, e.g. because they are after Peeling mechanical treatments, such as chopping onions and slicing potaffeine for chips, are intended to be subjected to the are difficult to carry out on a soft material.

It is also known. Fruits and vegetables by heating with watery Peeling solutions of ammonium salts, which are considerably weaker alkalis than sodium and potassium hydroxide. This procedure is but very inconvenient or expensive, since in practice it can only be carried out in pressure vessels, otherwise ammonia during heating

909834/0745

It has now been found according to the invention that the disadvantages the known method for peeling fruits and vegetables can eliminate all or part of the use of potassium carbonate and / or potassium phosphate as alkali. This achieves a faster peeling than when using sodium or potassium hydroxide, and thus better utilization of performance of the apparatus. Open containers can also be used.

In the present context, peeling fruit and vegetables means removing the outer layer of cells from the relevant part of the plant to understand whether this outer layer corresponds to an actual peel that is clear from the rest of the fruit or Vegetables such as potatoes and apples, or whether the outer layer is basically of the same character as that of the other parts of the plant, such as onions, where there is no sharp transition between dry and juicy peel.

Fruit and vegetables are usually not peeled 100%, i.e. that the peel is not removed from 100% of the surface because this will take too long and thereby the inside of the fruit or vegetable would change. In general, a degree of peeling of 80 to 100% is found to be satisfactory, depending on the type of plant part concerned addicted.

The invention is illustrated below with the aid of the following examples, all of which are carried out by immersing the fruit or vegetable in question in the heated aqueous solution of alkali and held therein until a degree of peeling determined to be acceptable has been achieved. Then it becomes from the peeling liquid removed and rinsed with water, and the peeled area is measured in percent.

Example 1. Potatoes.

Bintje potatoes were used and the peeling liquid was kept at 90 ° C. The chemicals used were 9 g K ₂ CO ₃ per liter and 56 g KOH per liter. This resulted in a peeling degree of 85%

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reached in 6 minutes. If potassium hydroxide is used alone at a concentration that is the same concentration of potassium - ^ - ions guaranteed, namely 63 g KOH per liter, a peeling degree of only 65% is achieved in 6 minutes.

For comparison, a peeling time of 8 minutes was required to achieve the same peeling percentage if the chemicals used were the corresponding sodium compounds in a concentration that ensured the same normality of the peeling solution, namely 7 g Na ₃ CO ₃ per liter and 40 g NaOH per liter.

Example 2.

That not excluding the potassium ion as distinct from the sodium ion for the result is crucial, visible ist'aus a further comparative experiment, other origin used than that in the Bintje potatoes in Example 1 were used, and in which the peeling liquid again held at 90 ⁰ C became. When the chemicals used were 69 g K ₃ CO ₃ and 42 g KOH per liter, a peel degree of 75% was achieved in 6 minutes, whereas a peel degree of only 35% was achieved when the chemicals used 74.5 g KCl per liter and was 42 grams of KOH per liter.

Example 3. Potatoes.

Bintje potatoes were used and the peeling liquid was kept at 90 ° C. The chemicals used were 40 g K ₃ PO ₄ and 46 g KOH per liter. As a result, a degree of peeling of 90% was achieved in 6 minutes.

For comparison, a peeling time of 8 minutes was required to achieve the same degree of peeling if the chemicals used were the corresponding sodium compounds in a concentration that ensured the same normality of the peeling solution, namely 31 g Na ₃ PO ₄ per liter and 33 g NaOH per liter.

Example 4. Apples.

Spartan apples were used and the peeling liquid was on

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ORIGINAL INSPECTED

-Q-

Maintained 7O ° C. The chemicals used were 35 g K ₃ CO ₃ per liter and 21 g KOH per liter. As a result, a degree of peeling of 85% ^ was achieved in 6 minutes.

If the chemicals used were the corresponding sodium compounds in a concentration that is the same as normal
Guaranteed peeling solution, namely 27 g Na ₃ CO ₃ and 15 g NaOH per
Liters, it took 10 minutes to achieve a peel degree of 80%.

Example 5. Apples.

Spartan apples were used, and the peeling liquid was kept at 70 ⁰ C. The chemicals used were 35 g K ₃ PO ₄ and 18 g KOH per liter. As a result, a degree of peeling of 90% was achieved in 6 minutes.

For comparison, a peeling time of 10 minutes was required
85% peeling can be achieved if the corresponding sodium compounds were used in a concentration that ensures the same normality of the peeling solution, namely 27 g Na ₃ PO and 13 g NaOH per liter.

Example 6. Apples.

Springrove apples were used and the peel was made
kept at 70 ^° C. When the chemicals used were 69 g of K ₃ CO ₃ and 28 g of KOH per liter, a peel degree of 100% was achieved in 6 minutes. On the other hand, when the chemicals were 74.5 g KCl and 28 g KOH, no peeling at all was achieved in 6 minutes.

Example 7. Onions.

Zittauer onions were used, and the peeling liquid was maintained at 8O ⁰ C. If the chemicals used are 9 g of K ₃ CO ₃ and
14 g of KOH per liter were, a peel degree of 85% was achieved in 6 minutes.

In order to achieve the same degree of peeling, a treatment time was given

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ORIGINAL INSPECTED

of 10 minutes if the chemicals used were the corresponding sodium compounds in a concentration that ensures the same normality of the peeling liquid, namely 7 g Na ₃ CO ₃ and 10 g NaOH per liter.

Example 8. Onions.

Zittauer onion were used / and the peeling liquid was maintained at 8O ⁰ C. By using 35g K-PO. a degree of peeling of 85% was achieved in 6 minutes. The use of 27 g Wa ₃ PO ₄ per liter only ensured a degree of peeling of 70% in 10 minutes.

Example 9. Onions.

Stuttgart onions were used and the peeling liquid was kept at 70 ° C. By using 71 g of K ₃ PO ₄ per liter (which ensures a normality of 1), a degree of peeling of 90% was achieved in 10 minutes. 84 g KOH per liter, which ensure the same normality of the peeling solution, give a peeling degree of 97% in 10 minutes, and 60 g NaOH per liter, which also ensure the same normality of the peeling solution, achieve an unsatisfactory peeling degree of 30% in 10 minutes .

909854/0745 "

Claims (1)

Claim Process for peeling fruit and vegetables by heating with aqueous alkali, characterized in that the alkali is whole or in some cases potassium carbonate and / or potassium phosphate can be used. 909834/0745