MX2007010310A - Process for using nejayote. - Google Patents

Abstract

The present invention is related to the masa and tortilla industry, and more particularly to a novel ecological process intended to produce masa for manufacturing tortillas, wherein effluents having a high biological oxygen demand(BOD) are removed. The advantages of the present process over the state-of-the-art processes are that the present invention does not require an excessive transformation of itself, thereby reducing the required investment and the operation costs, also increasing the maize/masa yield, and providing the resulting masa with the maize components lost during the nixtamalization process. Said process consists in the following steps: 1) mixing the nejayote with nixtamal washing water, 2) decanting said mixture, 3) using said thick solids with the content of water used to mill the nixtamal, 4) the supernatant remaining in the decantation container is bubbled with combustion gases of the boiler. 4) flocculating the suspended solids of the supernatant by adding a floccu lant thereto; 5) separating the sludges after the flocculation and 6) leading water to the drainage or to a deposit so that it is reused.

Description

PROCESS OF USING THE NEJAYOTE FIELD OF THE INVENTION The present invention is related to the dough and tortilla industry and more specifically, to a new ecological process for the production of tortilla dough, in which effluents with high biological oxygen demand (BOD) are eliminated.

BACKGROUND OF THE INVENTION From the origin of the nixtamalization, the production of the cooking liquor, commonly called nexayote, presented a serious problem due to the oxygen requirements for its decomposition. Since the liquor has a high content of nutrients such as starch, dextrins, B vitamins, lipids, amino acids, polypeptides, celluloses, etc., it is a product that can easily be decomposed, but highly polluting due to its oxygen demand.

In addition to the oxygen demand, in its decomposition, bad odor gases and even combustible biogas are generated.

In the state of the art there are many procedures that have tried to solve this problem.

There is a procedure that consists in reusing the nexayote in the nixtamalization process, that is, replacing a part of the water for nixtamalization with the nexayote and washing water. However, although this solution allows to solve the problem temporarily, in reality it displaces it in this dimension. As you have more cycles of recirculation, the liquor is concentrated and each time you have to reuse a smaller amount of this liquor and each time a greater amount of new water, and finally it was required to be eliminated in some way, handling a liquor with increased problems in terms of decomposition by requiring more oxygen and in terms of the production of bad odors and biogas.

Another method of the state of the art for disposing of this liquor, due to its nutritional content, is to use it as animal feed, especially pigs. Although this solution is very promising, however, it requires a transport infrastructure to collect this material and take it to the farms.

Another procedure was to use this material, the liquor, as a food source for the production of unicellular protein, with the disadvantage of its pH and high calcium content.

Finally, a novel method of disposing of this liquor that allows to overcome the drawbacks of the procedures of the state of the art, would give a competitive advantage to the one who developed this process.

OBJECTIVES OF THE INVENTION One of the objectives of the present invention is the reuse of the nexayote without excessive transformation thereof, decreasing the required investment.

Another objective is to make possible a nexayote disposal procedure that requires a low operating cost.

Still another objective is to give this procedure the quality of increasing the yield of the corn in mass by restoring to the dough the components of the corn that was lost during the nixtamalization.

And all those objectives that will become apparent with the description of the process that is ongoing.

BRIEF DESCRIPTION OF THE INVENTION In a few words The present invention consists in the collection of the nexayote, its subsequent mixing with the nixtamal washing water, its decanting to remove the suspended solids, the bubbling in the remaining water, the combustion gases of the burners that heat the water for the process of nixtamalization, the application of flocculants in water with a pH close to neutrality, the separation of the sludge and the arrangement of the water with a minimum of solids and an acceptable pH to send the water to drainage or to use it once again in another nixtamal charge.

Although in the nexayote several nutrients go, the particle size of these nutrients (amino acids, polypeptides, sugars, amyloses and to milopectinas, vitamins, etc.) and the viscosity of the liquor make the decantation difficult. The washing water comprises an important charge, especially of celluloses, whose source is the so-called pericarp technically of the grain and commonly known as skins.

On the other hand, the mixture of the washing water and the cooking liquor (the so-called nexayote) is also called nexayote in the present description. This mixture has a higher content of fiber for the skins that were dragged during the washing of the nixta-mal, and when having a larger amount of water, the decantation is carried out. better by decreasing the viscosity of the liquid.

Decanting allows the separation of relatively large solids with a high water content. In the present process, these separated solids, with their water content, are sent to a deposit from which they are extracted to replace the grinding water, resulting in a mass with improved strap.

To the water without the above-mentioned solids immediately above, the combustion gases of the boiler are bubbled, achieving a double purpose, on the one hand to reduce the pH of the water and on the other to reduce the CO2 and the CO of the gases emitted to the water. atmosphere.

Subsequent flocculation allows solid particles of small size to be removed from water with a pH close to neutrality. The sludges, in minimum quantity, are separated from the water and this will have adequate characteristics to be eliminated or to be reused.

Due to the characteristics of the water obtained after the treatment of the nexayote, this can be reused in the nixtamalization of the corn n times, achieving a considerable saving of potable water.

Next, a brief description of the figure annexed to the present description will be made, which for illustrative purposes, but not limiting you add to this BRIEF DESCRIPTION OF THE FIGURE Figure 1 illustrates a schematic diagram of a preferred embodiment of the process.

For a better understanding of the invention, the detailed description of the invention will be carried out based on FIG. 1, which is attached to the present description for non-limiting illustrative purposes.

DETAILED DESCRIPTION More extensively, the procedure is described below giving details thereof.

To achieve the treatment of the Nejayote in the mill, it is necessary to make a sanitary reception of the water, install a decanter and make a connection from the boiler to the decanter. With this, it is hoped that the nejayote will be able to comply with the norm 002 of SEMARNAT.

For the application of the process object of the present description, a tank for the accumulation of nejayote water and washing water was installed in the nixtamal mill.

Inside the tank a pump was installed for the recirculation of the nejayote with the purpose of removing the corn that is stuck in the Nixtamalization tubs and therefore having a saving of drinking water.

A decanter was also installed in the nixtamal mill, which is used for sedimentation and separation of solids. Once separated, the solids are reused to make dough and later tortillas, replacing them with the water that is used directly in the milling, this substitution can be 100% and the sensory tests carried out show that people do not find differences between the normal tortillas and those that contain recycled solids (perhaps due to the low proportion in which they are), while the rollability shows that tortillas with recirculating solids are more elastic.

Once the solids are separated, the supernatant is treated before discharging into the sewer system. In the boiler a pipe was installed towards the decanter through which the combustion gases are going to pass, for the neutralization of the supernatant. In order to separate the solids that are still in the supernatant a chemical flocculant of aluminum is used that allows the precipitation of all the solids. And finally, once the solids have been separated, the liquid has been neutralized and cooled, the sewer is discharged.

The corn free of dust and foreign matter is transported by any conveyor means of the clean corn hopper 2 to the mixing tank 3 of corn, lime and hot water. In this tub, the lime feeder 1, the corn conveyor means 15 and the hot water conduit 16 coming from the boiler 4 open out.

Once the trinomial corn, water and mixed lime is transported from the mixing tank 3 to the nixtamalization tank (s) 5, through the conveyor means 14. The nixtamalization tank chosen to be fed is selected by opening the gate 17 corresponding.

Once the nixtamalization is complete, the selected nixtamalization tank opens its corresponding lower hatch 18, discharging the nixtamal and the nexayote to the nixtamal conveyor and nexayote 13. This conveyor moves nixtamal and nexayote to the washing hopper 6, with a mesh lower to retain the washed nixtamal and allow the passage of the nexayote to the hopper of nexayote 7.

The nixtamal is transported to the mill 8 by means of a medium nixtamal transporter 12.

At the bottom of the hopper nexayote 7 is located a pump to send, by means of a bypass 20 the nexayote, either towards the nixtamalization tubs to drag the nixtamal that has been stuck on its wall, in an option or to the Decanting tank of nexayote 10 in another option.

Decanting time is variable and will depend on many factors, but as soon as you have the separation of the large solids, these are sent directly to the mill or to a warehouse that stores it, to be added to the nixtamal to be ground in replacement of grinding water.

When these solids have been removed from the decanting tank, the key 21 is closed and the combustion gases of the boiler 4 are injected into the water remaining in the tank, lowering the pH of said water and then adding a chemical flocculant of aluminum to separate the solid particles in suspension, separating later the sludges, by decantation and obtaining a water that complies with the norms of SEMARNAT, to send this water to the drainage or to reuse it in another cycle of nixtamalization.

Having described the invention in sufficient detail to induce a third party with average knowledge in the field to re- To produce the invention with the results indicated in the present description, we will proceed to claim the material that is hereby incorporated into the state of the art and therefore deserves protection.

Claims (3)

R E I V I N D I C A C I O N S

1. Procedure for the use of the nexayote characterized by consisting of the following steps: 1) mix the nexayote with the wash water of nixtamal, 2) decant that mixture to separate the coarse solids, with a certain amount of water, 3) use those coarse solids with the water content they have to replace the grinding water, 4) to the supernatant remaining in the decanting tank after the coarse solids have been separated, the combustion gases of the boiler are bubbled to lower the pH! 4) f locute the suspended solids of the supernatant by adding a flocculant; 5) Separate the sludge after the flocculation and 6) Send the water to the drain or to a deposit for its reuse.

2, Procedure for the use of the nexayote, as claimed in the preceding claim, further characterized in that the flocculant is a chemical flocculant.

3. Procedure for the use of the nexayote, as claimed in the preceding claim, further characterized in that the flocculant is an aluminum flocculant. E S U M E The present invention is related to the dough and tortilla industry and more specifically, to a new ecological process for the production of tortilla dough, in which effluents with high biological oxygen demand (BOD) are eliminated. The advantages of the present process with respect to the state of the art procedures are that the present process does not involve an excessive transformation of the same, decreasing the required investment, requiring a low operating cost and increasing the yield of the corn in dough is the mass of the components of corn that was lost during nixtamalization. Said process consists of the steps of 1) mixing the nexayote with the nixtamal wash water, 2) decanting that mixture, 3) using those coarse solids with the water content they have in the milling of the nixtamal, 4) to the supernatant that remains in the decanting tank, the combustion gases of the boiler are bubbled; 4) flocculate the suspended solids of the supernatant by adding a flocculant; 5) Separate the sludge after flocculation and 6) Send the water to the drain or to a tank for reuse.