ES2752747B2 - DEHYDRATED POTATO FLOUR AND PROCESS FOR ITS PREPARATION - Google Patents

Description

DESCRIPTION

DEHYDRATED POTATO FLOUR AND PROCESS FOR ITS PREPARATION

TECHNICAL SECTOR

The present invention relates to the field of the food industry, and more particularly to a new process for dehydrating potatoes and obtaining dehydrated potato flour. The dehydrated potato flour obtained from said process and its use in food is also an object of the invention.

BACKGROUND OF THE INVENTION

Potato flour is a very popular flour today for being gluten-free. For this reason, it is highly recommended for people with celiac disease or gluten intolerance, and is also very rich in iron and carbohydrates. Due to its pleasant flavor, it is widely used for the preparation of various preparations such as in the formulation of bread doughs, as a thickener in stews, etc.

The present invention arises from the need to develop a new process for obtaining this type of flour based on dehydrated potatoes. As background closer to the present invention, the following documents of the state of the art should be mentioned:

Chinese patent application CN103960622, which refers to a process to prepare dehydrated potato flour that comprises washing, peeling and chopping the potatoes, washing them again with water at a temperature equal to or lower than 30 ° C, blanching the potatoes at a temperature equal to or greater than 95 ° C, dehydrate the potatoes in an oven at a temperature between 50 and 60 ° C and prepare the flour by grinding.

Also, the Chinese patent application CN102697005 refers to a process to prepare sweet potato flour that includes the steps of cleaning and cutting sweet potatoes, blanching at a temperature of 90 to 95 ° C for 10 minutes, dehydrating at 120 ° C for a time of 10 to 15 minutes and grind and sift the sweet potato.

Chinese patent application CN106616633 refers to a process for obtaining sweet potato flour that comprises the steps of washing, peeling and cutting sweet potatoes, blanching at a temperature of 90 to 100 ° C, draining and dehydrating in an oven at a temperature from 110 to 120 ° C for 20 to 30 minutes until a moisture content of less than 8 or 10% is obtained and the dehydrated sweet potatoes are crushed and sieved.

The main problem that has been encountered when treating potatoes is their enzymatic browning as a consequence of polyphenoloxidase (PPO), also known as catechol oxidase. It has been observed that, in order to control the enzymatic transformation of potatoes, the treatments described in the state of the art require the use of low temperatures (around 50 ° C), which has the disadvantage of the long time required For the drying of the potatoes, about 6 hours, time that causes the alteration of the taste of the final product. Other alternative methods use high temperatures, around 100 ° C, which, although they allow to reduce the drying time, also cause an alternation of the flavor of the flour and a considerable loss of nutrients.

The present invention refers to a new process for the production of dehydrated potato flours with very good organoleptic characteristics and a nutritional composition far superior to that of other potato flours. For this, an optimal combination of the process conditions has been achieved that allow minimizing the reduction of the nutritional properties of the raw potato, managing to maintain a very high percentage of protein in the final product. In particular, the claimed process makes it possible to reduce the percentage of protein reduction, keeping it in a range between 1 and 2.6%.

DESCRIPTION OF THE INVENTION

The present invention relates to a process for the preparation of dehydrated potato flour from potatoes comprising:

a) cutting the potatoes, without peeling, preferably until obtaining potato strips with a size between 5 and 10 mm and more preferably between 7 and 9 mm thick. This size has been shown to be especially advantageous for the contact surface to be adequate to optimize the subsequent drying process;

b) blanching the potatoes at a temperature between 95 and 100 ° C for less than 5 minutes, and preferably between 2 and 3.5 minutes, then immersing the potatoes in water at a temperature less than or equal to 12 ° C, and preferably between 8 and 12 ° C, for a time between 10 and 20 minutes and more preferably between 12 and 16 minutes;

c) Drain the potatoes and arrange them evenly in trays and place them in an oven where they are subjected to a dehydration process at a temperature between 70 and 80 ° C and more preferably between 73 and 77 ° C for a time between 5 and 7 hours, and more preferably 5.5 hours; and

d) preparing the flour by grinding, preferably in a hammer mill and sieving with a sieve. Preferably, the final product will have an average particle size greater than 500 pm and less than 3 mm.

The process described above allows to obtain a product of high nutritional quality with the least possible processing and without the use of chemical preservatives and antioxidants.

One of the advantages of the process object of the invention compared to other processes of the state of the art is that it is carried out by subjecting the washed potato to the heat treatment without peeling. In this way, all the nutrients present in the skin of potatoes are used, especially the fiber and minerals.

Regarding the temperature of the process, it has been shown that the combination of claimed temperatures allows obtaining a flour with the desired nutritional and organoleptic characteristics, much higher than the nutritional values of currently commercially available potato flours.

In a particular embodiment of the invention, the process will comprise a previous stage of cleaning the potatoes by washing, preferably with water, as well as eliminating possible impurities such as sprouts or the black spots usually present on potatoes after harvest.

Through the claimed dehydration process, it is possible to reduce the content of water from the potatoes in a percentage comprised between 70 and 80% by weight, this being the usual water content in potatoes. Therefore, it is a particularly efficient process to obtain dehydrated potatoes.

Another object of the invention is the dehydrated potato flour obtained from the process described above, which is characterized by presenting an optimal moisture value (between 9 and 15% by weight, measured according to the ISO R- 1442 at a working temperature of 120 ° C) and of average particle size (greater than 500 gm and less than 3 mm).

Finally, the object of the invention is the use of the claimed dehydrated potato flour in food.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a series of photographs corresponding to the selection of varieties of potatoes used in a particular embodiment of the process object of the invention, as will be described in the "Preferred description of the invention" section. In particular:

- Figure 1A shows the Andean Sunside potato variety \

- Figure 1B shows the Lily Rose potato variety \

- Figure 1C shows the potato variety Vitelotte \

- Figure 1D shows the Prunelle potato variety .

Figure 2 shows the potatoes cut into 8 mm thick strips and homogeneously placed on the trays where they are subjected to the dehydration process at a temperature of 75 ° C.

Figure 3 shows the potatoes of the Andean Sunside (left) and Prunelle (right) varieties after being blanched.

PREFERRED EMBODIMENT OF THE INVENTION

In particular embodiments of the invention it is possible to carry out an initial selection of the potatoes that are going to be used as raw material in the process for obtaining dehydrated potato flours. This selection can be made to choose those potato varieties with the best nutritional properties, in order to to obtain flours with nutritional values far above the rest of the potato flours available today. In particular, the potato varieties selected were Andean Sunside, LilyRose, Vitelotte and Prunelle.

Thus, "yellow" meat varieties were selected, which are rich in carotenoids, vitamin B6 (> 40 mg / 100 g), vitamin C (> 30 mg / 100 g), potassium (> 1200 mg / 100 g ) and copper (> 0.2 mg / 100 g), as well as "purple / violet" varieties of meat, rich in anthocyanins, vitamin B6 (> 100 mg / 100 g), vitamin C (> 35 mg / 100 g) , potassium (> 1,300 mg / 100 g), iron (> 3 mg / 100 g), magnesium (> 65 mg / 100 g) and copper (> 0.2 mg / 100 g).

In both cases, the percentage of protein is between 9 and 12% by weight of the total, this being a differential factor with respect to the rest of the processes currently available for obtaining dehydrated potato flours, in which the values nutritional characteristics of the final product are not an essential characteristic to take into account.

In a particular embodiment of the invention, the process was carried out starting with the cutting of the potatoes, without peeling, until obtaining strips of 8 mm thickness, this being an adequate value to increase the contact surface of the potatoes and facilitate the dehydration process.

Next, the potatoes were subjected to a blanching process at a temperature between 95 and 100 ° C, for 2, 2.5, 3 and 3.5 minutes.

After the heat treatment, the potatoes were immersed in water at a temperature of between 8 and 12 ° C, for a time of between 13 and 16 minutes.

Subsequently, the potatoes were homogeneously arranged in trays, placing them in an oven at a temperature of 75 ° C for 5.5 h.

Subsequently, the flour was prepared by grinding the potatoes in a hammer mill and a granulometric classification of the final product was carried out by screening, selecting an average particle size of less than 3 mm.

After subjecting the potatoes to different blanching times (2, 2.5, 3 and 3.5 minutes), no significant differences were visually observed at the organoleptic level.

All the varieties of potatoes presented a good state, maintaining the color and without showing evidence of oxidation.

The measurement of the percentage by weight of water lost during the dehydration process allowed to demonstrate the efficiency of the process, being able to eliminate around 70-80% of the weight of water from the potatoes.

After obtaining the flour, a sensory consumption test was carried out with 100 people in which the appearance, texture, flavor and general satisfaction of the consumers were evaluated, obtaining up to 80.4% acceptance.

Therefore, it has been shown that the claimed process, in addition to making it possible to obtain a flour with a nutritional composition very similar to that of raw potato and superior to that of potato flours on the market, manages to reduce the process time , avoiding browning or oxidation of the final product and achieving superior organoleptic properties than those obtained at lower and higher temperatures, as described to date in the state of the art.

Claims (4)

1. Process for the preparation of dehydrated potato flour from potatoes comprising: a) cut the potatoes, without peeling, until obtaining potato strips with a size between 5 and 10 mm thick; b) blanching the unpeeled potatoes at a temperature between 95 and 100 ° C for less than 5 minutes, then immersing the potatoes in water at a temperature less than or equal to 12 ° C for a time between 10 and 20 minutes; c) draining the potatoes and arranging them evenly in trays that are then placed in an oven where they are subjected to a dehydration process at a temperature between 70 and 80 ° C for a time between 5 and 7 hours; and d) preparing the potato flour by crushing and screening the potatoes until obtaining an average particle size greater than 500 gm and less than 3 mm. 2. Process according to claim 1, wherein the cutting of the potatoes is carried out until obtaining potato strips with a size between 7 and 9 mm thick. 3. Process according to claim 1 or 2, characterized in that it comprises a preliminary step of preparing the potatoes by washing and cleaning impurities. 4. Dehydrated potato flour obtained according to a process according to any one of claims 1 to 3, characterized in that it has a humidity value between 9 and 15% by weight and an average particle size greater than 500 gm and less than 3 mm.