Technical Field

The invention pertains to a production method related to delaying the onset of surface crystallization issues throughout the shelf life of dried figs, which provide a probiotic content in figs rich in dietary fiber.

Prior Art

Dried figs are defined as fig fruits belonging to the species Ficus carica L., which are offered for consumption after natural or artificial drying processes following the harvest of the fruits. Dried figs are among the widely produced dried fruits globally due to their rich sugar content (-48% fructose and glucose), essential amino acids, carotene, thiamine, riboflavin, and various minerals, while having low fat content. The processing steps that dried figs undergo from orchard to consumption can be summarized as pollination, ripening, harvesting, drying, sorting, fumigation, removal of aflatoxin-contaminated dried figs, washing, shaping, packaging, and storage.

The drying process takes place on racks which are plastic or wooden drying trays, for about 2- 3 days until the moisture content reaches approximately 22-24%. In order to expedite and ensure a healthier process, drying can also be conducted in closed tunnels. Following the exhibition period of approximately 4-5 days, figs classified as scrap are separated, and the sound, dried figs are taken to producer warehouses.

The most commonly encountered quality issue in dried figs is the presence of aflatoxin, a mycotoxin. However, preventive measures taken during the production stages help to eliminate this problem. Another quality problem encountered throughout the shelf life of the product is surface sugar crystallization. Over a period of 4-6 months, the surfaces of dried figs tend to sugar crystallize. This issue is a natural reaction that occurs when the sugar in the fig interacts with water, moving onto the drier surface of the fig, depending on its moisture content, water activity, and relative humidity of the environment. However, an excess amount of sugar crystallization or larger crystals is an undesirable condition for consumers. Coating or penetration of probiotic microorganisms into food products is a well-known practice in the food industry. Typically, in such applications, probiotic strains that have demonstrated their probiotic effect mechanism, often derived from lactic acid bacteria, are preferred. However, these applications aim to impart a probiotic effect to food products, targeting the production of functional goods. Simultaneously, specific water activity values below or maximum storage condition requirements for these probiotics commonly used in the market pose constraints on their utilization in food products.

In the prior art of the subject, some references have been encountered. One of these is document CN112772762A, which relates to a method involving the use of the Lactobacillus microorganism in the coating applied to dried fruits with the aim of exhibiting a probiotic effect. The document details the steps involved in applying this method to achieve a probiotic effect in the coating applied to dried fruits.

The document US20210120832A1 discusses the method steps for applying a coating using Bacillus subtilis microorganism on dried apple slices to exhibit a probiotic effect. In this study, the fermentation solution of Bacillus subtilis is sprayed using atomization spray technology onto both sides of the apple slice at 60°C-80°C using atomization spray technology. Subsequently, to achieve the burnt black appearance on the apple slices, the apple-carbonyl- ammonia reaction is initiated by applying radiation.

As mentioned in the documents, there are various dried fruit products available in the market that utilize different probiotic microorganisms. However, specific studies regarding the usage quantity of probiotic microorganisms applied for delaying the sugaring effect in dried figs and acquiring a probiotic effect have not been conducted.

As a result of the mentioned shortcomings and deficiencies, there arises a need for innovation in the relevant technical field.

AIM OF THE INVENTION

The present invention relates to a method of dried fig production that meets the mentioned requirements, eliminates all disadvantages, and brings additional advantages.

The aim of the invention is to present a method that provides probiotic content in dried figs rich in dietary fiber while delaying the onset of surface sugaring throughout its shelf life. The aim of the invention is to impart functional properties to dried figs by coating them with a homogeneous solution obtained by mixing the proven probiotic microorganism with water in order to demonstrate probiotic effects in the gastrointestinal system. Additionally, this method ensures the delay of surface sugaring in dried figs.

The aim of the invention is to obtain dried figs that acquire probiotic properties and exhibit effects such as delaying surface sugaring, which is often perceived by many consumers as mold, while also maintaining visual product color appeal throughout the shelf life.

The invention aimed at achieving the purposes described above is a production method for dried figs rich in dietary fiber, providing probiotic content while delaying the onset of surface sugaring throughout the shelf life characterized in that; a) Procuring dried figs, b) Preparation of a probiotic water solution by mixing encapsulated probiotic microorganisms with water to provide a stabilizing co-encapsulation effect for probiotic culture, c) Application of the mentioned probiotic water solution onto the surface of dried figs, d) Packaging the obtained probiotic figs and storing them at room temperature.

The probiotic water solution prepared in step b to achieve the objectives of the invention contains a minimum of 0.5% and a maximum of 2.5% water per 1 kg of figs, and a minimum of 0.1% and a maximum of 1.36% microorganisms in encapsulated form as probiotics.

The microorganism mentioned in step b to achieve the objectives of the invention is either Bacillus subtilis or Bacillus coagulans.

The probiotic water solution prepared in step b to achieve the objectives of the invention contains a minimum of 0.03% encapsulated Bacillus Subtilis.

In another preferred embodiment of the invention, the probiotic is in powdered form and has been obtained through lyophilization or dry spray methods.

In another preferred embodiment of the invention, the structure of the powdered probiotic contains at least one of maltodextrin, ascorbic acid, dextrin, or inulin.

In another preferred embodiment of the invention the mentioned microorganism is 8.2x10 ^A 9 CFU/40 grams. In another preferred embodiment of the invention, Bacillus subtilis is in the spore form at 25x10 ^A 9 CFU/g, while Bacillus coagulans is in the spore form at 15x10 ^A 9 CFU/g.

In another preferred embodiment of the invention, the probiotic water solution prepared in step b is applied to the surfaces of dried figs through controlled dosing spraying.

In another preferred embodiment of the invention, the probiotic water solution prepared in step a is continuously mixed both before and during application to dried fig surfaces to prevent phase separation, and then sprayed onto the surfaces.

In another preferred embodiment of the invention, following step c, the probiotic dried figs are mixed in a closed drum tank to ensure homogeneous distribution on the surfaces of the dried figs.

The structural and characteristic features of the invention, as well as all its advantages, will be better understood through the detailed description provided below. Therefore, evaluation should also be based on considering this detailed explanation.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 : The SEM (Scanning Electron Microscope) image of the control dried figs with crystallized sugar on the surface.

Figure 2: The SEM (Scanning Electron Microscope) image of dried figs coated with Bacillus Subtilis Rosell-179 probiotic solution.

Figure 3: The SEM (Scanning Electron Microscope) image of dried figs coated with Bacillus Coagulans probiotic solution.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, a method for producing dried figs is described by means of examples only for clarifying the subject matter such that no limiting effect is created.

The invention pertains to a production method providing probiotic content in dried figs rich in dietary fiber while delaying the onset of surface sugaring throughout the shelf life.

Within the scope of the invention, a method has been developed considering the daily intake of probiotics, aiming to delay the onset of a quality issue, namely surface sugaring. The method subject to the invention involves suspending probiotic microorganisms in water and applying them to the surface of dried figs. This ensures the stability of probiotic activity until the end of the shelf life, while simultaneously delaying the onset of sugaring on the surface of dried figs

The dried fig production method is characterized in that;

• Producing dried figs,

• Preparing a probiotic water solution by mixing microorganisms in encapsulated form with water to provide a stabilizing co-encapsulation effect for probiotic culture,

• Applying the mentioned probiotic water solution to the surface of dried figs through controlled dosing spraying,

• Packaging the obtained probiotic figs and storing them at room temperature

As part of the invention, an optimization study was conducted considering the daily intake limits of probiotic microorganisms for probiotic effects on the final product, the water activity of the final product, and technically applicable coating rates to delay sugaring. Through the optimization efforts, it was determined that, to prevent sugaring, for 1 kg of dried figs (based on the total weight of dried figs), a minimum of 0.5% and a maximum of 2.5% water, and a minimum of 0.1% and a maximum of 1 .36% microorganisms in encapsulated form as probiotics can be used.

In the preferred embodiment of the invention, for adequate delay of sugaring, Bacillus Subtilis Rosell®-179 strain is used as the probiotic at a minimum rate of 0.03% for 1 kg of dried figs. The encapsulation structure includes the mentioned powdered probiotic mixture containing maltodextrin and ascorbic acid. The mentioned probiotic microorganism, maltodextrin, ascorbic acid, or the mixture of probiotic microorganisms can be obtained in lyophilized or spray-dried form before preparing the probiotic water solution. Accordingly, the probiotic microorganism is mixed with water, following a co-encapsulation method with a kind of auxiliary encapsulation before preparing the probiotic water solution.

In an alternative embodiment of the invention, Bacillus coagulans GBI-30 6086 strain can be used as the probiotic. The encapsulation structure includes the mentioned powdered probiotic mixture containing inulin. The mentioned probiotic microorganism, inulin, or the mixture of probiotic microorganisms can be obtained in lyophilized or spray-dried form before preparing the probiotic water solution. The recommended daily intake for probiotic effect in the gastrointestinal system for the utilized raw material and probiotic microorganism is a minimum of 500 million CFU/40 grams and a maximum of 1 billion CFU/40 grams. However, it has been determined that technically, the probiotic solution can be sprayed to the surface optimally up to a maximum of 8.2x10 ^A 9 CFU/40 grams without the need for re-drying the dried figs.

In the preferred configuration of the invention, Bacillus subtilis is in the spore form at 25x10 ⁹ CFU/g, while Bacillus coagulans is in the spore form at 15x10 ⁹ CFU/g.

The probiotic water solution was prepared by homogeneously mixing encapsulated probiotic microorganisms with water in the specified amounts for the preparation of the probiotic solution. As this prepared solution has the potential to undergo phase separation, it was continuously mixed both before and during application to the surfaces of dried figs to prevent phase separation, and then sprayed onto the surfaces. Following the spraying, the dried fig surfaces were mixed in a closed drum tank to ensure a homogeneous distribution of the probiotic on the dried figs' surfaces. After mixing, the products were packaged and stored at room temperature.

Throughout the shelf life, it was observed that the probiotic products monitored delayed the formation of powdered sugar compared to the current product by 50% over 10 months. In the 12th month, 100% of the surface of the dried figs (control) stored in 250-gram packets was covered with crystallized sugar, whereas the dried figs coated with probiotic solution showed no crystallized sugar on the surface; only a fine powder sugar was observed.

In preferred embodiment of the invention, dried figs were processed into slices through freezing, slicing, and drying. The dried fig slicez were then coated with the probiotic solution according to the specified coating rates within the scope of the invention. During the shelf life study, it was observed that the fig slices gained probiotic properties, delayed sugaring, and maintained visual color appeal throughout the shelf life, in addition to other effects.

Throughout the shelf life, the color values of the products, captured in JPEG format, were analyzed using an image analysis technique based on the international color measurement system developed by CIE (Commission Internationale de I’Eclairage). In this study, products were analyzed in Adobe Photoshop 8 Software (Adobe Systems Incorporated, San Jose, CA) using the Lab* color scale. Lab* is based on the CIE XYZ intermediate color space, simulating human perception. L* represents the brightness or lightness component ranging from 0 for black to 100 for white, while a* and b* are two chromatic components varying between -120 and +120, representing the range from green to red and blue to yellow, respectively. Considering these values, it was determined how probiotic solution-coated fig crisps affected the L and B values. At the beginning of its shelf life, the L value was measured at 33 units. After 13 months, the current products exhibited a decrease in color intensity indicated by an L* value decrease of 20 units, while the products coated with probiotic solution showed a decrease of only 6 units, indicating that they darkened less compared to the initial color. When examining the b* values, the products with an initial value of 35 units decreased by 24 units in the control product after 13 months. However, the probiotic solution-coated products decreased by 9 units, suggesting that they exhibited a slower shift toward a yellow hue compared to the current product.

In the context of the study, two different probiotics (Bacillus Subtilis and Bacillus Coagulans) were applied to dried figs, one set without any treatment and another set showing crystallization on the surface. Images of the dried figs were captured: Figure 1 displays the SEM (Scanning Electron Microscope) image of the dried fig surface showing crystallization, considered as the control. Figure 2 illustrates the SEM image of dried figs treated with Bacillus Subtilis Rosell-179 probiotics, and Figure 3 presents the SEM image of dried figs treated with Bacillus Coagulans GBI-30 6086 probiotics. When examining the images at the same magnification (100x), it's evident that the control product (with observed crystallization) displays granulations of about half a millimeter in size on the surface of the fig. However, in the images of probiotic-treated figs where crystallization is absent, the granulation is observed less densely.

Surface coating techniques can also ensure the increased stability of different probiotic microorganisms on dried figs. However, this application may become more costly due to the increased quantity of probiotics used compared to our current method. These studies are generally conducted to impart functional properties to products. It is estimated that there are around 1 trillion microbial species rapidly growing worldwide. In the food market, there is significant interest in newly recommended bacteria as probiotics and in new foods containing these strains. For these new probiotic candidates, the lack of sufficient experience regarding their use in foods raises reliability concerns when introducing these new strains to the market.