FOOD PRODUCT FORMING PROCESS AND FOOD PRODUCT

FIELD OF THE INVENTION

The present invention relates to a food product forming process for the dehydration and drying of fruits and/or vegetables, the process generally allows keeping the nutrients of the fruit and/or vegetable and also increasing its shelf life. Certain embodiments herein disclosed relate to producing a food product, such as a bar, produced from a double compression process.

Certain embodiments herein disclosed relate to a dehydration and drying process comprising cold compression of fruit.

In another embodiment of the invention a dehydrated fruit product is provided which keeps all of its nutrients.

In an additional embodiment, the invention provides a food product starting from a dehydrated fruit, wherein the food product is selected from snacks and fruit bars among others.

BACKGROUND

In Mexico, fruit and vegetable consumption per capita is 1 10 grams per day, so that producers and authorities seek to increase the average daily consumption so as to prevent and combat obesity and overweight traits.

Proper consumption of fruits and vegetables grants individuals health benefits, such as:

• Lowering the risk of certain types of cancer and other chronic diseases;

• Greater amount of antioxidants;

• Stimulating the immune system;

• Modulating steroid hormone concentration and hormonal metabolism; • Lowering blood pressure; and

• Increasing antiviral and antibacterial activity, among other benefits.

Apples are one of the most complete fruits that can be included in diets. A great percentage of apples are water (80-90%), however, apples also provide sugars, such as fructose among others, which have rapid assimilation in our bodies, vitamin E, tocopherol and vitamin C.

Apple skin has substances with highly important properties for human's health, specifically polyphenols and phytochemicals, which are substances with antioxidant effects, that is, which prevent the development of certain diseases and some types of cancer. Their potassium content makes apples a fruit with a diuretic effect, and thus recommended for people with liquid retention diseases, such as arterial hypertension.

Another property of apples is its fiber, which prevents or decreases constipation, helping regulate intestinal transit. On the other hand, its pectin retains water, which makes apples an important fruit when a patient has diarrhea. Given its richness in tannins, they are also recommended for diarrhea, especially when the solids oxidize.

Apple trees are one of the most cultivated species in the world on a global scale. Asia is the continent with the highest production; the European continent being the second most important geographic area, followed by North America, where the United States stands out as the world's second highest producer; lastly in terms of production are South America, Africa and Oceania, respectively.

Currently, fresh fruit presents the following problems:

a) The useful life of fresh fruit is conditioned by its handling, both before and after its harvesting.

b) The mechanical damage caused by processing, favors the browning phenomenon, texture degradation, and nutritional and sensory value.

c) During transport, the length of trip must be the shortest possible. Similarly, the packaging of fruits needs to be done with care to avoid damage to the fruit.

d) The higher the storage temperature of fresh fruit, the greater amount of CO ₂ the fruit produces, as well as accelerating the degradation process of starch in the fruit's sugars, which modifies the texture of the fruit.

Given the above-mentioned problems, a need exists in the field for new processes that allows keeping the nutritional properties of the fruit. The present invention solves said problems by dehydrating fruit.

Currently, there are different dehydration processes for fruits, such as:

1. Sulfide Dehydration

Sulfide dehydration calls for selecting the fruit, given its ripeness, followed by washing, classifying, cleansing, exfoliation, extracting samples and cutting said fruit into wedges. If the fruit is apples, the apple wedges are dried to eliminate a greater part of its moisture to produce a semi- dry texture. The moisture content of the finished product is not higher than 24% by weight.

The product is then sulphureted with a solution at a range of 0.2-0.5% to delay spots caused by oxidation of the fruit.

2. Osmotic Dehydration

This process allows partial elimination of water from fruit tissues in a hypertonic solution (sugars and/or salt) without damaging the fruit and unfavorably affecting its quality.

The critical temperature at which the variation in the permeability of the membrane is produced, is estimated for fruit orchards as being in a range between about 50°C-55°C.

3. Lyophilization

In the lyophylization process, moisture is eliminated from the fruit by sublimation; therefore, there is no liquid transfer from the center of the mass towards the surface.

Disadvantages in the Processing and Final Fruit Product

As shown below in Table 1, the disadvantages of the different known drying processes in the field, as well as the final product are:

Table 1. Disadvantages in Prior Art Processes and their Final Product

Apple Composition

As shown below, table 2 demonstrates the composition and retention parameters of apples:

Table 2. Composition and retention parameters of the differing apple nutrients.

Vitamin and Mineral Stability

According to the United States Department of Agriculture (USDA) in fruit drying processes the following retention values are achieved in the different nutrients, such as vitamins and minerals, which are reflected in Table 3 below.

Table 3. Factors in nutrient retention

Table 4 shown below, highlights the different parameters to which vitamins are sensitive, the following being:

Table 4. Vitamin parameter sensitivity.

Fruits which are adequately dehydrated at a lower moisture level, that is less than 5%, have an optimal drying at about 60°C and are able to maintain their mineral content practically unchanged; therefore dehydration processes are useful in keeping nutritional content of the final product. In so far as minerals, these are more resistant to manufacturing processes than vitamins. However, mineral stability can be affected and certain changes can occur when they are exposed to heat, air or light.

Minerals such as copper, iron and zinc can also be affected by moisture and can react with other food components such as proteins and carbohydrates. Minerals can be lost by leaching, cooking or water processing.

Table 5 shows the maximum nutrient loss under different treatments.

Table 5. Maximum nutrient loss under different treatments.

Therefore, it is clear that nutrient loss during dehydration can be decreased with low temperature dehydration/drying and a shortening of dehydration/drying times. Also, the above shows that storage in dry conditions and with low oxygen levels increases nutrient conservation.

BRIEF DESCRIPTION OF THE INVENTION

The present invention discloses a food product manufacturing process for fruits and/or vegetables, such as apples, providing thus a food product whose shelf life is stable. The process is carried out without essentially modifying nutrimental and organoleptic properties of the fruit, and without substantially adding additives and/or ingredients to achieve a compressed fruit product, such as a compressed apple product, with a pleasant texture and flavor.

Other objects and advantages of the present invention will be evident having as reference the specification in view of the following figures.

FIGURES

The illustrated embodiment may be disclosed with reference to the figures which:

Figure 1 shows a compression process diagram for fruits, such as apples.

Figure 2 shows a step-by-step diagram of the process of the present invention for fruits such as apples.

Figure 3 shows a flow diagram of the cold double compression process of the present invention.

All the figures are drawn for ease of the basic explanation of the teachings of the present invention. The extension of the Figures with respect to the number, position, relation and dimensions of the parts of the preferred embodiment(s) will be explained within the skill of the art once the teachings of the present invention have been read and understood. Furthermore, exact dimensions and proportions to make up the force, weight and specific requirements are also within the skill in the art after the teachings of the present invention have been read and understood. DETAILED DESCRIPTION

Definitions

The term "about" provides an additional determined range. The term is defined in the following manner: the additional range provided by the term is that of approximately ± 15%. By way of example, but not in a limitative manner, if the specification or claim states "about 60°C", the range should be construed to be about 51°C to 69°C. Three main embodiments are disclosed by the present invention, a first is a dehydration at low temperatures, a second is a dehydration at high temperatures and a third is a dehydration without liquid/solid separation.

The fruit/vegetable forming process of the present invention, is described as follows:

1. Washing and Drying

To obtain a product with a high hygiene standard, fruits must be washed and dried to eliminate contamination such as fertilizers and bug repellants. The washing of the fruit is performed by techniques which may be known in the state of the art, for example, rotatory drums, immersion tubs, conveyor through spray machines, etc. After washing the fruit, the drying of the fruit can be performed in techniques known in the state of the art; the drying step is preferably carried out at a room temperature. One skilled in the art may recognize that this step is optional and can be carried out only if needed. 1.1. Fruit Peeling

Some fruits can be processed directly after the wash and dry step, such as apples, pears, and grapes, among others, however, for several fruits the skin must be separated before continuing with the process such as bananas, cantaloupe, and water-melon, among others. Again, one skilled in the art may recognize that this step is optional, and can depend on the fruit to be processed.

Peeling can be performed by suitable equipment known in the art. The equipment can vary depending on the fruit to be peeled.

2. Separation of Liquids from Solids

Fruits contain up to about 80% water, thus a large amount of hydro soluble materials from are retained, therefore fruits are rich in carbohydrates, for example fiber, however their protein content is low.

Different equipment for separating liquids from solids can be used, for example decanters, centrifuges, screw presses, turbo filters, band filters and combinations thereof, among others. In a preferred embodiment of the invention the used separating equipment is a screw press which compresses fruit batches. Despite the used equipment, the target separation is separating between about 70 to about 95% of water (liquid) from solids, in this case fruit pulp. The fruit pulp is left with a moisture content of about 60%-90%, preferably about 75%. In an alternate embodiment of the invention, liquids are not separated from solids and enter into the drying step as a mixture containing both liquids and solids, until obtaining a paste, which is optionally milled, optionally heated (the process could be performed without heating) and shaped as a bar in accordance with the below methods. The evaporation step is not necessary for this alternative.

3.1.1. First Embodiment - Solids Drying at Low Temperatures

Drying technology offers options for keeping nutritional food features, increasing useful life and lowering development potential of microorganisms, as well as undesired chemical reactions.

In a preferred embodiment of the first embodiment, a low temperature dryer is used, such as a vacuum drying is used since it is an adequate system for food products which are sensitive to heat and oxidation, as is the case of fruits and vegetables. The color change in the drying food product can be affected by the thickness of the material and the temperature at which the food product is exposed; for these reasons this is the preferred embodiment of the first embodiment. However, other embodiments different to vacuum drying can be used in accordance with one skilled in the art. The fruit solids enter in the low temperature dryer at a temperature of about 60°C, preferably less than 60°C, more preferably a temperature between 30°C to 55°C, preferably at a temperature between about 50°C to about 55°C and more preferably at a temperature about 55°C.

However, other embodiments can be used in accordance with one skilled in the art: a) Drying at atmospheric pressure: In this alternative, the solids enter in the low temperature dryer at a temperature preferably about 60°C, preferably less than about 60°C, preferably between about 30°C to about 55°C, more preferably about 50°C to about 55°C and more preferably at a temperature about 55°C. The pressure in the low temperature dryer is an atmospheric pressure. The time in the low temperature dryer is preferably more than 60 minutes, more preferably between about 1 to about 95 hours and yet more preferably between about 24 to about 72 hours.

b) Vacuum Drying: With this method, the solids enter in the low temperature dryer at the temperatures indicated above. The solids are dried at vacuum, preferably at a low pressure oscillating from about 0.15 to about 0.75 atmospheres (about 0.02 MPa-0.08 MPa) and more preferably between about 0.26 atmospheres to about 0.59 atmospheres (about 0.03 MPa-0.06 MPa). The time in the low temperature dryer is preferably less than 150 minutes, preferably between about 0.01 to about 120 minutes, preferably less than 60 minutes, more preferably between about 5 to about 55 minutes and yet more preferably between about 20 to about 45 minutes..

Using the dried methods mentioned above, a product with a moisture content between about 4% and about 15% and more preferably between about 4% to about 8% can be achieved.

3.1. II. Second Embodiment - Solids Drying at High Temperatures

In the second embodiment, a high temperature drying is used rather than the low temperature dryer.

There are three preferred methods for carrying out this second embodiment:

a) Drying at very high temperature: The fruit solids enter in an end of a rotative drier having a length of about 10 meters at a temperature less than 900°C, preferably at a temperature of about 650 to about 900 °C, more preferably between about 700°C to about 850°C and more preferably at a temperature between about 750°C to about 800°C. When the solids reach the opposite end of the rotative drier the temperature drier has decreased to about 300°C to about 100°C, preferably to about 100°C to about 200 °C. The time in the drier is about 15 minutes to about 120 minutes, 15 minutes to 60 minutes, 30 mia 50 minutes. The pressure in the high temperature dryer is an atmosphere pressure.

b) Drying at medium temperature: A medium temperature drying is used rather than the low or high temperature dryer. The solids enter in the drier at a temperature from about 50°C to about 160°C, preferably about 60°C to about 140°C, more preferably 70°C to about 120 °C and more preferably about 70°C to 100°C, for about 5 minutes to about 7 hours, preferably about 15 minutes to about 7 hours, preferably from 0.5 to about 6 hours, more preferably from about 0.5 to about 4 hours and more preferably between about 60 to about 120 minutes. The pressure in the medium temperature dryer is a pressure of about 0.3 atm (about 0.03 MPa) to about an atmosphere pressure, more preferably between about 0.3 atm (about 0.03 MPa) to about 0.8 atmospheres (0.08MPa), and more preferably the pressure in the dryer is an atmosphere pressure. It is preferable in a preferred embodiment to dry at an atmosphere pressure for a time of between about 30 minutes to 240 minutes. c) Vacuum Drying: The solids are dried at vacuum, preferably at a pressure from about 0.1 atmospheres to about 1 atmospheres; preferably about 0.3 to about 0.8 atmospheres (about 0.03 MPa to about 0.08 MPa), at a temperature from about 50°C to about 120°C, preferably about 60°C to about 100°C. The time in the drier is about 0.01 minutes to about 140 minutes, preferably about 0.01 minutes to about 120 minutes, preferably about 0.1 minutes to about 60 minutes, preferably between about 15 minutes to about 60 minutes and more preferably between about 30 minutes to about 60 minutes. In an alternate embodiment, it is preferable to dry the solids at a pressure of between 0.3 to about 0.8 atmospheres for a time of between about 1 minutes to about 40 minutes. With the above temperature, pressure and times a product with a moisture content between about 4% to about 30%, preferably about 4% to about 25% and more preferably between about 4% to about 15% can be achieved.

For one skilled in the art, it would be evident that in some cases the resulting dried product may have moisture content slightly higher than the amounts specified above; however, the drying of the product may be completed in the mixing step in view of the temperatures used therein.

3.2. Pasteurization

In an alternate embodiment, the solids dried for any of the methods disclosed above could optionally be subject to a pasteurization process according to know methods in the art. Preferably, said pasteurization process is carried out before the evaporation step.

3.2.1. First Embodiment - Low Temperature Liquid Evaporation

Given that liquids have been separated from solids, the liquids are evaporated at a low temperature, preferably in a vacuum evaporation process. However, one skilled in the art may recognize that any type of evaporator may be used. The temperature of the evaporation process is preferably less than 60°C, more preferably a temperature between 30°C to 55°C and more preferably at a temperature between 30°C to 45°C. The pressure in the low temperature evaporator is of between about 0.04 atm to about 0.65 atm, preferably 0.04 to 0.3 atm, more preferably 0.1 to about 0.3 atm The time in the low temperature evaporator is from about 0.01 minute to about 300 minutes, more preferably between 30 minutes to 240 minutes and more preferably from about 0.01 minutes to about 5 minutes. With the above temperature, pressure and times an evaporation of the liquids are concentrated until reaching about 30°Brix to about 90°Brix, preferably 50°Brix to about 90°C and more preferably between about 60°Brix to about 75°Brix. The above low temperature and low pressure evaporation process Used to concentrate the liquids keep the organoleptic properties of the liquids and prove a final food product with a higher quality. One may recognize that the low temperature liquid evaporation may be used with either the low temperature solids drying or the high temperature solids drying indistinctly.

3.2.II. Second Embodiment - Medium Temperature Liquid Evaporation

In the second embodiment, a medium temperature drying is used rather than the low temperature dryer. One may recognize that the medium temperature liquid evaporation may be used with either the low temperature solids drying or the high temperature solids drying indistinctly. Given that liquids have been separated from solids, the liquids are evaporated at a medium temperature, preferably in a vacuum evaporation process. However, one skilled in the art may recognize that any type of evaporator may be used. The temperature of the evaporation process is preferably higher than about 60°C, more preferably the temperature is between about 65°C to about120°C and more preferably the temperature isbetween about 70°C to about 100°C. The pressure in the medium temperature evaporator is of between about 0.3 to about 0.9 atmospheres (about 0.03 MPa-0.09 MPa)and more preferably between about 0.3 and 0.45 atmospheres (about 0.03MPa-0.05 MPa) . The time in the medium temperature evaporator is about 0.01 minute to about 300 minutes, more preferably between 0.01 minutes to 15 minutes and more preferably between about 0.01 minutes to about 5 minutes. With the above temperature, pressure and times an evaporation of the liquids are concentrated until reaching about 30 °Brix to about 90°Brix, and more preferably between about 60°Brix to about 75°Brix.

4. Milling

This step applies for the products obtained from the previous methods, including the production obtained from the embodiment wherein liquids are not separated from solids. Once the desired moisture in the solids is obtained, the solids are placed in a mill to decrease the particle size of the solids until a fine powder is obtained. The particle size depends on the fruit being used. During milling, in some cases a color change from yellow to maroon in the solids due to condensation catalyzed by oxidases in the labile phenolic components of the pressed fruit. The mill is preferably a low speed mill, such as a Pulvex® mill, which mills usually at a rate of about 100kg/hr . The milling rate may suffer variations in function of the capacity of the low speed mill used.

The solids are placed for an average time of between about 0.01 minutes to about 10 minutes, more preferably about 0.01 minutes to about 4 minutes.

5. Mixing

Once the powder and the liquid concentrate are obtained, they are mixed until obtaining a paste with a degree of uniformity. The mixture is carried out in a mixing device, such as a double Z Mixer or/and a vacuum mixer. The powder and the liquid are mixed for a period of time between about 5 to about 40 minutes, more preferably between about 6 to about 20 minutes and more preferably between about 6 minutes to about 15 minutes. Heat and vacuum during mixture may be used, wherein the preferred temperatures are low to medium and are preferably between about 30°C to about 1 15°C, more preferably between 40°C to 80°C. If heat is used during mixture, the mixed product may be cooked.

If high temperatures are used for drying solids or medium temperatures are used for evaporating liquids, the addition of additives and/or ingredients, such as vitamins and/or minerals may be necessary to provide a vitamin and mineral rich product. Such addition may be carried out during the mixing of the paste. If additives and/or ingredients are added, the same times and temperatures are expected for the mixing step.

In the embodiment wherein the separation of liquids and solids is not performed, if the drying step is carried at high or medium temperatures, the addition of additives and/or ingredients, such as vitamins and/or minerals may be necessary to provide a vitamin and mineral rich product.

In some instances, the mixing step permits complete the drying of the product obtained in the drying steps previously mentioned.

6. Compression

After a uniform paste is obtained, the paste is compressed providing the paste with the desired shape. The paste is preferably formed by double compression. The compression may be obtained by means of a cold compression extruders such as those known in the art, such as a single or double screw extruder or a extruder with two finned blades and two screws However, other types of known compressors may be used as may be seen by a technician in the field. The desired temperatures during compression are below 80°C, more preferably below 70°C and even more preferably below 60°C. A water-cooled extruder may be used to obtain such cold compression. The preferred pressure of the compressor is between about 1 and about 5 atmospheres (about 0.5 MPa).

In a preferred embodiment, the food product forming process is formed by a double compression. The first compression step is performed at the beginning of the process when the fruit is compressed for separating liquids and solids and the second compression step is carried out when the paste is compressed for providing the desired shape. 7. Packaging

After the food product is compressed, said compressed food product is packaged in packages, such as metalized bi-axially oriented polypropylene (BOPP) bags, using a machine for individual packaging (Flow Pack) of each of the compressed food products. The package is preferably sealed using heat. The package may be vacuumed prior to the seal. Example

Composition of the Compressed Apple

An apple bar called #APP.027 was developed, wherein Table 6 shows a comparison between the nutritional compositions of a fresh apple, a dehydrated apple and the prototype obtained through the process of the present invention, in differing portion sizes.

Table 6 - Apple Composition

Shelf Life

Water plays a very important role in the speed at which foods deteriorate. Given this, the Aqueous Activity concept (A _w ) is widely used in food preservation. The Prototype #AA.027 of the present invention has a 0.7 A _w and a pH between 4-4.5.

According to standard data in the foods industry a low A _w (between 0.62 and 0.85) molds produce the most frequent microbial alterations. Within those values, bacteria are generally inhibited. A _w values lower than 0.7 are considered to be a guarantee for the stability of the food products.

It was observed that the stability of the compressed apple is within the standard values, having a 10.3% moisture, while using a metalized bi-axially oriented polypropylene (BOPP) packaging material to avoid possible alterations in the nutrients by effects of light. With these parameters a shelf life of about 3 to 5 months can be recommended.

Alterations to the disclosed structure in the present may be seen by those skilled in the art. However, it must be understood that the present specification relates to the preferred embodiments of the invention, which is for illustrative purposes only and must not be construed as a limitation for the invention. All embodiments which are within the spirit of the invention are considered to be included within the scope of the invention.