WO2013079742A1

WO2013079742A1 - Method for softening chufa flatsedge

Info

Publication number: WO2013079742A1
Application number: PCT/ES2012/000295
Authority: WO
Inventors: Purificación GARCIA SEGOVIA; Javier Martínez Monzó
Original assignee: Universidad Politecnica De Valencia (Upv)
Priority date: 2011-11-28
Filing date: 2012-11-27
Publication date: 2013-06-06
Also published as: ES2410782B1; ES2410782A1

Abstract

The invention relates to a method for softening chufa flatsedge, comprising the following steps: soaking the chufa flatsedge in a liquid extractant medium with a concentration of a strong base of between 1 and 7%, and washing the resulting chufa flatsedge with water.

Description

Chufas softening procedure

The present invention is within the field of food biotechnology, and refers to a method of softening of chufas (cyperus esculentus), so that they can be used in other applications within the field of food. The products obtained in accordance with the process of the present invention are highly nutritious.

The process of the invention has application in the food composition preparation industry.

STATE OF THE PREVIOUS TECHNIQUE

The chufa is a tuber of the rhizome of the Cyoerus esculentus L, herbaceous plant of the Ciperáceas family, whose composition, especially as regards the protein content, seems to vary depending on the origin of the chufa and its variety.

This tuber is approximately one centimeter in length, is yellow skinned and white pulp, and constitutes the root of a species of sedge. Thanks to its organoleptic qualities, its use and consumption spreads rapidly, its diffusion being retained due to the difficulties of its conservation in a stable way and maintaining its natural qualities, as well as the lack of diversification of products obtained from it as they are The horchata and the flours.

Carbohydrates are the major components of chufa, followed by lipids and proteins. The highest percentage corresponds to starch, followed by sugars consisting mostly of sucrose, and the presence in very small amounts of glucose, fructose and galactose and oligosaccharides has been reported. The lipid content of the chufa is high, exceeding 20% being even greater than that of some nuts such as peanuts and nuts. From a nutritional point of view, it is worth noting its richness in unsaturated fatty acids (83.8%) and especially the high percentage of oleic acid (70%). The fatty acid profile of chufa oil resembles those corresponding to olive and hazelnut oils (Linssen et al., Food Chem, 28 (4) 279-285 (1998), Coskuner et al., J Sci Food Agrie, 82 (6) 625-631 (2002)). The high variability of the chufa's protein content is evident when you compare chufas from different origins. Albumin is the majority fraction (81.2% of the total), it is soluble in water which favors its presence in the horchata. In a smaller proportion there are other proteins such as globulins (4.8%), glutelins (2.3%) and prolamines (0.9%) (Morell J, Barber S. Chufa and horchata: physical, chemical and nutritional characteristics. Institute of Agrochemistry and Food Technology, Valencia (1983). Among the amino acids that constitute it, the high content of arginine stands out.

Of the fiber components, one of the most prominent is lignin. Lignins are polymers insoluble in acids and soluble in strong alkalis, which are not digested or absorbed and are not attacked by the microflora of the colon. They can bind to bile acids and other organic compounds (for example, cholesterol), delaying or decreasing the absorption in the small intestine of said components. The degree of lignification significantly affects the digestibility of the fiber. Lignin, which increases ostensibly in the cell wall with maturation, is resistant to bacterial degradation, and its fiber content reduces the digestibility of fibrous polysaccharides. The possibility of softening this tuber would not only allow this product to be used again, but also increase digestibility and therefore a better use of its nutritional value. The possibility of obtaining a softening of this tuber could be interesting for fresh consumption, as well as the possibility of using it for other uses. That is why different procedures have been studied to achieve this goal such as the use of ultrasound, enzymatic treatments, heat treatments, however, with none of these procedures convincing results have been achieved.

Therefore it would be desirable to be able to develop a new procedure by means of which an effective softening of this tuber is carried out, and thus the product that is obtained to be able to allocate it for the elaboration of food products.

DESCRIPTION OF THE INVENTION The present invention solves one of the problems presented by this tuber, and is the possibility of use as an ingredient for the preparation of dishes, providing a process that allows its softening so that its texture is pleasant to the palate. Therefore, a first aspect of the present invention relates to a chufa softening process, which comprises the following steps: a) macerating the chufas in a liquid medium with a strong base concentration of 1 to 7%; Y

b) wash the chufas resulting from the previous stage with water.

In the present invention, maceration is understood as a solid-liquid extraction process where the solid product (chufa) has a series of soluble compounds in the extracting liquid medium which are those that are intended to be extracted. According to a preferred embodiment, the extracting liquid medium is water.

According to another preferred embodiment, the strong base is a strong hydroxyl base, selected from the group consisting of KOH, NaOH or LiOH, preferably NaOH.

According to another preferred embodiment the strong base is in a concentration of 4 to 7% and more preferably, 5% to 7%. According to another preferred embodiment the maceration step is carried out for a time interval of between 10 and 72 hours, preferably for 16 hours.

According to another preferred embodiment the maceration step is carried out at a temperature range of between 15 and 60 ° C, preferably at 35 ° C.

According to another preferred embodiment, step b) of washing is carried out with decalcified water in order to remove the remains of the strong base from step a). According to another preferred embodiment, step b) of washing is carried out by stirring with a bath with magnetic or mechanical stirring.

A second aspect of the present invention relates to the softened chufa obtainable by the above procedure.

A third aspect of the present invention relates to a food product comprising the softened chufa previously obtained.

A fourth aspect refers to the use of softened chufa for the production of food products.

In this same sense, these food products are made by cooking, pickling and swelling by frying. Among the products that are they can get these oils, horchata, snacks (swollen chufas) and energy bars (from cereals and chufa).

Throughout the description and the claims the word "comprises" and its variants are not intended to exclude other technical characteristics, additives, components or steps. For those skilled in the art, other objects, advantages and features of the invention will be derived partly from the description and partly from the practice of the invention. The following figures and examples are provided by way of illustration, and are not intended to be limiting of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1. Represents the measure of the maximum force (N) for the different treatments tested.

Figure 2. Represents the measure of fracturability (mm) for the different treatments tested.

Figure 3. Represents the work measurement from 0 to 2.5 mm (g s) for the different treatments tested.

Figure 4. Represents the work measurement of 2.5 to 5 mm (g s) for the different treatments tested.

EXAMPLES The invention will now be illustrated by tests carried out by the inventors, which demonstrates the effectiveness of the process of the invention in obtaining softened chuffle products.

Procedure for obtaining softened chufas

The procedure for carrying out the softening of chufas is detailed below, as previously described in the present invention: In the first place, a selection and washing of the tubers to be treated was carried out, specifically a total of approximately 45 g of chufas per experience to be carried out.

Subsequently, a stage of maceration of the chufas was carried out, by means of an aqueous solution of sodium hydroxide at different concentrations and times as can be seen in Table 1.

Tests Temperature (° C) Time (h) NaOH concentration (%)

1 35 12 3

2 30 8 7

3 30 16 7

4 30 16 3

5 35 16 5

6 30 12 5

7 25 12 3

8 30 12 5

g 30 8 3

10 35 12 7

11 35 8 5

12 25 16 5

13 25 8 5

14 30 12 5

15 25 12 7

Table 1. Conditions of temperature, time and concentration of NaOH used. Once the maceration stage was finished, the tubers were washed and thus achieved the removal of the remains of the base of the previous stage.

Finally, a moisture and texture measurement step was carried out by puncture test (15 different samples and 25 repetitions of each sample).

The results obtained are shown in table 2.

Table 2 shows the results obtained in the texture tests for the different treatments applied.

In Figures 1 to 4, the results obtained for the tests carried out with each of the parameters analyzed can be observed graphically, that is to say the maximum force, the fracturability, the work of 0 to 2.5 mm and the work of 2 , 5 to 5 mm. It was established based on the characteristics of the samples that the value of the maximum force was less than 7 N and the fracturability less than 2.5 N since above these values the samples were "not adequate" in an expert panel Tasters for fresh consumption. However, they had excellent properties for use in food products made by cooking, pickling or swelling by frying. From these tests, it can be concluded that samples 1, 4, 6, 7, 8, 9 and 13 have been somewhat harder than the other samples, since they reported maximum strength and fracturability values outside the range of "acceptability" For fresh use. However, it should be taken into account that a longer maceration time allows satisfactory values to be obtained even for low concentrations of the base used. In this sense, the chufas prepared with a concentration of 3% NaOH and a maceration time of 72 hours or even 24 hours, give rise to adequate results of both texture and moisture.

Table 3 shows the most advantageous values of the textural parameters, temperature and treatment time, concentration of NaOH and humidity for possible treatment conditions that can be applied to obtain softened chufas.

Sample Temperature (° C) Time (h) NaOH (%) Humidity (%)

2 30 8 7 47.90

3 30 16 7 45.40

5 35 16 5 46.70

10 35 12 7 47.60

11 35 8 5 46.60

12 25 16 5 49.63

14 30 12 5 51, 70

15 25 12 7 48.70 201

9

Table 3. Values of textural parameters and humidity for the selected treatments.

As can be seen in Table 3, the optimal ranges of NaOH concentration are 5-7%, the time between 8 and 16 hours and the temperature between 25 and 35 ° C. Combinations of these parameters in the ranges discussed above result in a product (softened chufa) with acceptable characteristics and suitable for the uses considered (fresh consumption, cooking, pickling and frying swelling) as well as for the type of products that can be get (oils, horchata, snacks, puffed chufas or energy bars from cereals and chufa).

Claims

1. Procedure for softening of chufas comprising the following stages: a) macerating the chufas in a liquid extractant medium with a concentration of a strong base of 1 to 7%; and b) wash the chufas resulting from the previous stage with water.

2. The method according to claim 1, wherein the extracting liquid medium is water.

3. The process according to any of claims 1 or 2, wherein the strong base is of the hydroxyl type.

4. The process according to any one of claims 1 to 3, wherein the strong base is selected from the group consisting of KOH, NaOH or LiOH.

5. The process according to any of claims 1 to 4, wherein the strong base is NaOH.

6. The process according to any of claims 1 to 5, wherein the strong base is in a concentration of 4 to 7%.

7. The method according to any of claims 1 to 6, wherein the strong base is in a concentration of 5 to 7%.

8. The method according to any of claims 1 to 7, wherein the maceration step is carried out for a time interval of between 10 and 72 hours.

9. The method according to any of claims 1 to 8, wherein the maceration step is carried out for 16 hours.

10. The process according to any of claims 1 to 9, wherein the maceration step is carried out in a temperature range between

15 and 60 ° C.

11. The process according to any of claims 1 to 10, wherein the maceration step is carried out at 35 ° C.

12. The process according to any one of claims 1 to 11, wherein the washing stage b) is carried out with decalcified water in order to remove the remains of the strong base of stage a).

13. The method according to any one of claims 1 to 12, wherein step b) of washing is carried out by stirring with a bath with mechanical or magnetic stirring.

14. Softened chufa obtainable by the method of any one of claims 1 to 13.

15. A food product comprising the softened chufa of claim 14.

16. Use of the softened chufa of claim 14, for the preparation of food products.