DE2340981C3 - Solution for chemical peeling of fruits and vegetables - Google Patents

Description

The third, probably the most common method is to use salt.

the fruit and vegetables to be peeled in a solution of since the ammonium salts are neither acidic nor acidic

To dive sodium hydroxide solution are at a temperature of caustic, they act as opposed to the sodium hydroxide solution usually 90-100 ⁰ C. The concen- 35 not by destruction of the plant tissue, the solution and the immersion time each concentration but by a detaching effect at the same adapted . Here the corrosive and soluble early removal of minor roots, eyes or properties of the caustic soda compared to the plant black points.

zen tissue exploited. The skin of the fruit and numerous tests have shown that ortho-

Part of this itself is destroyed, so that a phosphate is preferable, the ideal salt with reduced yield and in some cases also an optimal yield, the diammonia ortho, a change in taste and a change in phosphate alone (if the concentration of the color is acceptable must be taken. outside 5wt .-%, and at 20 ⁰ C with a pH value of the sodium hydroxide solution, the aggressivity of the about 8.2), or is in a mixture with Am-Bedieaungspersonal a constant threat. Since 45 monium carbonate (at a concentration of 5 % by weight the skin of the fruit or vegetable dissolves in the sodium bicarbonate and at 20 ° C with a pH of the aqueous solution lye solution, the latter gradually becomes from 8 to 9).

Enriched dirt and skin particles. The baths It was found that the ammonium must therefore constantly renewed. This salt is partly replaced by a strong alkaline base (Nafahren is therefore expensive and economically little renewable 50 or potassium) can be neutralized. the table, which has a strong impact on the price of the finished product - the results were satisfactory, although it has an effect. is appropriate if the ammonium salt is hydrolysed

The DT-OS 22 02 670 suggests that ammonium ions are supplied in sufficient quantities,
become known, the previously common sodium hydroxide solution through ammonium salts with a weaker pH value such as

to replace an agent containing alkanolamine. The 55 z. B. the sulfate and ammonium acetate (pH value only alkanolamine that has a peelability, the aqueous solution at 5 wt .-% and 20 ⁰ C: 6 to 7) is the monoethanolamine and in particular already have a useful peelability.
Connection with caustic potash. The monoethanolamine is the ammonium salts of orthophosphoric acid have

but a strong base. In connection with corrosive the great advantage that this acid has three acidities Alkali the pH value is even higher. The concentrated 60 different strengths, so that for each one solution thus represents for the specific case with the handling according to the degree of neutralization of the assigned personnel represent a danger. This is all the more reasonably good pH value and consequently an optimal one more than the monoethanolamine can be achieved apart from its concentration of ammonium ions Caustic power when heated can be a not insignificant one.

Has vapor tension, has an ammonia odor 65 In the new chemical peeling process as well as being flammable, extremely toxic and severely irritating. of fruits and vegetables, fruits and vegetables are up In addition, the wastewater is converted into a solution according to one of the above for 30 minutes dirty agent. listed embodiments immersed, wherein

this solution is kept at a temperature of 60 to 100 ° C. Immersion is preferred into the mixture for 3 to 10 minutes at one temperature from 80 to 95 ° C. The method can be carried out with the same devices that are used can be used for the caustic soda.

In industrial production, devices that are open to the atmosphere are placed after a During a certain operating time, a drop in pH was found, which was at least partially due to an ammonia distillation through the evaporation water, and the conversion of a certain amount of diammonia phosphate in monoammonia phosphate. If the pH value approaches 7, then the Restoration of diammonia phosphate may be required. It then becomes ammonia or a strong alkali (sodium or potassium) added, creating ammonia with strong acidity due to phosphoric acid is displaced with weak acidity and thus enables the formation of ammonium ions.

The ammonia distillation through evaporation water can be done by applying an oily layer are largely prevented. When using closed apparatus, there is naturally none Ammonia distillation.

The effectiveness of the aqueous solution can be further improved by adding a tensio-actif additive to the solution of the ammonium salts, which is intended to increase the wetting properties of the mixture and thereby activate its penetration. Alkyl benzenesulfonates (preferably of ammonium) in which the alkyl group contains 1 to 8 carbon atoms are particularly suitable for this purpose. Also suitable are the alkyl sulfonates with the formula RSO ₃ Me, where R is a hydrocarbon radical with 10 to 18 carbon atoms and Me is an ammonium ion or an alkali metal. It is also possible to use alkyl sulfates of the formula ROSO ₃ Me, where R is a straight or branched chain hydrocarbon radical of 6 to 10 carbon atoms. The ratio of the additives is preferably 0.02 to 0.2% by weight.

The new process does not have any of the disadvantages inherent in the previously known processes. the The yield of fruits and vegetables is far higher than that which can be achieved with sodium hydroxide. The products are in excellent condition after treatment; the natural color, the original size and the structure of the original surface is retained; the appearance is smooth and free from craters. It takes place no subsequent discoloration. The products have unchanged organoleptic properties. the new mixture also has excellent cleaning power, so that by simply rinsing it off with Water will get perfectly clean fruits and vegetables.

The new process is particularly suitable for peeling root vegetables such as oat root, carrots, turnips, turnips and fruits like tomatoes and peaches.

A concentrated solution can also be used when carrying out the peeling process, in which the components of the solution, but in multiple concentrations, are present, and the before Use is diluted with water in the desired ratio.

Some comparative examples are given below. which clearly show the advantages achieved by using the new process. At all Percentages are percentages by weight. In all cases a tensio-actif additive is mentioned in the above Ratio added.

Be i s ρ ι e 1 1 10 concentration With Peaches Removal of the skin from of the bathroom sodium With »5 pK value at 20 ° C hydroxide Diammonia Working temperature 20% phosphate Processing time 4% Yield of peeled 14th _ao product 93 ° C ± 2 8.2 1 min 93 ° C ± 2 70-75% 1 min 85-90%

It can be seen that at a weight ratio of the reagents between 1 and 5 and im other conditions being the same, the yield has increased by around 20% while at the same time making great savings of reagent.

Example 2

Removal of the skin from potatoes

In this case, sodium hydroxide solutions were 15% with a pH of 14 and an aqueous one Mixture of salmia salts used, consisting of 6% diammonia phosphate, 2% ammonium carbonate (pH 8.5 at 20 ° C).

The treatment time was 6 minutes in both cases, the working temperatures were 95 and 80 ° C, respectively. The results obtained were as follows:

In the case of the sodium

hydroxyd 60 to 65%

In the process with diammonia phosphate 75 to 80%

So you get one at a lower concentration of reagent and a lower temperature increased yield of around 20%.

Example 3
Removal of the skin of the roots

With

Sodium hydroxide

With

Diammonia phosphate

concentration
of the bathroom
pH value at 20 ° C
Working temperature

Treatment time

10%

93 ° C ± 2
! min

Peeled yield 45 - 50%

4%

8.2

93 ° C ± 2
8 min
65-70%

In this case, the reagent costs are approximately the same and the working conditions are the same a yield increase of around 40% is achieved. This generally confirms that the increase in yield increases as the specific surface area of the vegetable increases.

Example 4

Removing the skin of small-diameter (16-18mm) carrots

With With sodium Dianmoniac hydroxide phosphate concentration 7% 1.75% of the bathroom pH value at 20 ^° C 14th 8.1 Working temperature 93 ° C ± 2 93 ° C ± 2 Treatment time 4 - 5 min 4 - 5 min Yield of peeled 50% 80% product

With the diammonia phosphate, the yield has increased by 60%.

Example 5 Removal of the skin from beets (small ones)

With With sodium Diammonia hydroxide phosphate concentration 10% 3% of the bathroom pH at 2O ⁰ C 14th 8.2 Working temperature 93 ° C ± 2 93 ° C ± 2 Treatment time 8 - 9 min 8 - 9 min Yield of peeled 60% 80% product

With the diammonia phosphate, the yield has increased by 33%.

The main advantages of the new process are listed again below:

a) No caustic effect of the aqueous solution on the fruit or vegetables themselves, since only their Skin is removed, which increases the yield of peeled fruits or vegetables and their all properties are left unchanged.

ίο b) Since the skin of the fruit or vegetable does not dissolve, but is merely detached, there is no accumulation of the baths through deposits organic matter. Rather, the baths can easily be through a filter or the like to be cleaned again; a replacement is only required after a long period of operation. This will be Large amounts of reagents are saved, which makes the new process extremely economical will.

ao c) The aqueous solution does not change the shape, color or organoleptic properties of the treated fruit or vegetables changed, so that a better end product is obtained will.

as d) By simply washing the fruit or the Any bath residue is much easier to remove from vegetables than when they are used of sodium hydroxide, which is difficult to remove and therefore requires intensive rewashing

30 required.

e) As the diammonia phosphate, which is already used in the food industry for other purposes found, easily decomposed, it can be practically completely removed. On the other hand, however, are also any residues are absolutely harmless and do not pose a risk to human health represent.

Claims (1)

Is The invention is therefore based on the object Claim: a process for chemical peeling of fruit and To develop vegetables that can be used more economically from an aqueous solution and that, for human consumption, allow at least one ammonium salt of a mineral acid, 5 healthier treatment of the products,
where the ammonium salt is selected from the salts. This object is achieved according to the invention is that give a pH value of 7 to 9.5 at the previous solutions of 5 wt .-%, and by the use of an aqueous solution of Zubei 2O ⁰ C, minimum an ammonium salt of a mineral acid, for peeling fruit and vegetables. where the ammonium salt is selected from the salts, ίο which result in aqueous solutions of 5 wt .-% and at 2O ⁰ C a pH value of 7 to 9.5, for Peeling fruits and vegetables. In comparison to the agent according to DT-OS 22 02 670, the use according to the invention results in the The invention relates to the use of an aqueous 15 aqueous solution a better peeling process, a igen solution of at least one ammonium salt safer handling for the operating personnel, a mineral acid for chemical peeling of fruit a higher quality canned food, avoidance and vegetables. the pollution of sewage as well as a simpler When processing fruit and vegetables in the biological treatment of wastewater. About it In the canning industry, peeling is an essential part of the water-based one used lent work step. The peeling has so far been based on a solution to a recognized food additive, carried out three ways, namely mechanical, by d. H. a little alkaline and guaranteed non-toxic Water vapor, or a chemical product. by means of aqueous solutions of sodium hydroxide solution. This is the ammonium salt of a mineral acid Both of the first-mentioned methods require high as preferably selected from a group consisting of Investments, however, only result in a proportion - Monoammoniak-Orthophosphat.Diammoniak-Orthomäßig low yield of peeled fruit and phosphate, triammonia orthophosphate, double-sized vegetables. The use of steam also increases the phosphoric acid salts of ammonium and one Operating cost. Both methods are therefore only alkaline, base, ammonium carbonate and the mixtures applied when the chemical process passes 30 of these salmiac salts. The aqueous solution is removed can be used. expediently holds 0.5 to 15% by weight of the ammonium