Technical Field of the Invention

The present invention relates to a probiotic and prebiotic (symbiotic) ice cream with Oleaster and the production method thereof .

State of the Art

Ice cream is a dairy product made by mixing and freezing content-enriched milk and milk products with sweeteners, stabilizers, and/or emulsifiers and flavorings. Currently, Maras ice cream is commercially available and offered as plain or flavored with various flavorings.

Ice cream is specified as a high-calorie dairy product due to high sugar or glucose syrup and fat content. Therefore, ice cream cannot be consumed enough even though it is very popular and loved by those who have a weight problem and by those who do not want to gain weight.

Various studies have been conducted and many attempts have been made in order to reduce the calorie value of ice cream. These attempts included adding various dietary fibers to the formulation of ice cream, reducing the amount of sugar, or substituting sugar with artificial sweeteners. In these formulations, however, insulin, resistant starch added to ice cream in order to produce a dietary variant thereof, and adding various dietary fiber sources such as fructooligosaccharides to ice cream introduces significant incremental costs in terms of the production of ice cream. Adding sweeteners like sugar alcohol to ice cream in order to substitute sugar also increases the production costs, thereby introducing yet another disadvantage. STEVIA which is added to formulations in order to sweeten the ice cream is a plant of South American origin and agricultural activities for growing it is quite inadequate in Turkey.

Many implementations in the state of the art aimed to overcome said problems and attempted to reduce the calorie value of ice cream indirectly by reducing sugar and fat rates or by adding fruits and fruity flavors to ice cream for the purpose of reducing the calorie value thereof. However, adding fruits also increases the production costs of ice cream.

The developments realized in order to eliminate these problems existing in the state of the art have been searched by the inventor, leading the inventor to examine the documents mentioned below.

The invention disclosed in the European patent application numbered EP2835057(A1) and titled "Ice cream with a low sugar content comprising prebiotics partly or totally fermented by probiotics and method for making the ice cream" relates to a method for formulating ice cream. In said invention, a high amount of added sugar (0-20%) in the formulation of ice cream is substituted for complex sugars known as prebiotics which may be partially or completely fermented by probiotic bacteria of Bifidobacterium, Lactobacillus, and Streptococcus genera, or hydrolyzed by enzymes in order to obtain partially fermented ice cream with reduced sugar content and containing a great number of viable probiotic bacteria. In said invention, different prebiotics is either used as individual components or in mixtures and at various concentrations. Furthermore, said invention also relates to an ice cream comprising a content of added sugars such as sucrose, dextrose, glucose syrup that are partially or completely substituted for prebiotics and optionally fermented by probiotics and/or hydrolyzed by enzymes.

However, this application discloses no details about adding Oleaster. Hence, it includes no information about the use of Oleaster as a prebiotic. In said invention, complex sugars are added as prebiotics and a fermentation process is carried out in the production. In the present invention, the difference between the inventor's product and the state of the art is that Oleaster is used as a prebiotic and the inventive production method comprises no fermentation step.

The article titled "Antioxidant capacity and functionality of oleaster {Elaeagnus angustifolia L.) flour and crust in a new kind of fruity ice cream" present in the state of the art mentions adding Oleaster to ice cream. In this study, the influence of milled crust and flour from (-Elaeagnus angustifolia L.) separately added at different levels (1%, 2%, and 3%) on the physical, chemical, sensory, color properties and antioxidant properties of ice creams have been investigated. The article states that the increment of crust and flour level causes an increase of dry matter, acidity, viscosity, first dripping, complete melting, and vitamin C content. Furthermore, it is stated that the flour increases the overrun values in ice cream. The results presented in said article indicate that lyophilized oleaster extracts contain remarkable phenolic compounds. Moreover, the authors of the article state that lyophilized oleaster extracts exhibit a moderate in vitro antioxidant capacity. The addition of oleaster flour and crust affect sensory properties positively. The sensory results indicated that ice cream containing 2% of oleaster flour was the one that was scored the highest by the panelists. The article further states that oleaster flour and crust increase the sweetness of ice cream samples. Finally, the article concludes that these results showed that considerable nutritive and functional improvement could be attained by the addition of oleaster flour to ice cream formulation so that it could be used as natural antioxidants in ice cream as a source of flour with complacency.

However, this article does not mention the prebiotic function of Oleaster, nor does it disclose any information about adding prebiotics and/or probiotics to ice cream.

Hence, it can be said that the state of the art does not involve any information about using Oleaster in ice cream as a source of prebiotics. The inventor has managed to utilize Oleaster as a source of prebiotics in the novel ice cream formulation.

Probiotics are live bacteria and yeasts that are good for human health, particularly for the digestive system. Intestinal bacteria in the human digestive system protect the human body against harmful bacteria and fungi. Moreover, they protect the human immune system and regulate inflammation. Many intestinal bacteria make vitamin K and form short-chain fatty acids. Short-chain fatty acids are the main source of nutrition of cells lining the human colon. They promote forming a strong intestinal barrier that keeps harmful substances, viruses, and bacteria away. This may also reduce inflammation and cancer risk.

Prebiotics, on the other hand, is a type of fiber indigestible by the human body. They serve as a nutrient for probiotics which are tiny live organisms including bacteria and yeasts. Both prebiotics and probiotics are capable of supporting and promoting beneficial bacteria as well as other organisms inside the intestines.

The inventor has aimed to develop a novel ice cream and the production method thereof in order to overcome the problems and disadvantages of the aforementioned state of the art.

Description of the Invention

The object of the present invention is to produce a dietary and probiotic ice cream by means of the inventive ice cream in which Oleaster powder is used as a prebiotic and probiotic bacterium is added thereto.

Another object of the present invention is to develop a functional ice cream that features prebiotic and probiotic characteristics, is healthier, has reduced calorie value and sugar content, and enriched in terms of nutrients.

Yet another object of the present invention is to produce a symbiotic ice cream provided with high bioactivity and functional features. A low-calorie ice cream with a higher melting point (slower melting) is achieved by means of the present invention.

Oleaster powder is used as a dietary fiber and as a source of prebiotics. Moreover, it may also be used as a substitute for the main ingredients of ice cream such as milk powder and/or sugar. Since Oleaster powder contains approximately 10-20% of raw dietary fibers, it serves as a source of prebiotics and reduces the total calorie value of ice cream once added thereto. In the state of the art, probiotic bacteria are added to ice cream. In the present invention, however, Oleaster serves as a source of prebiotics. Probiotic bacteria adhere to intestines once they reach thereto and perform various activities that may be beneficial for human health. Oleaster powder included in the content (as a source of prebiotics) of the present invention provides the following advantages:

When added to ice cream together with probiotic bacteria, it promotes the development and survival thereof. When it is used in substitution for milk powder and/or sugar, it reduces the calorie value of ice cream. Hence, it causes a decrease in the amount of milk powder and sugar added to ice cream.

When it is used in substitute of milk powder, it increases the dry substance rate of ice cream and the water holding characteristic of the dietary fiber prevents ice cream from releasing its water content and from melting.

When it is used as a substitute for sugar, it naturally sweetens the product via the simple sugars it contains.

Description of the Figures

FIGURE 1 illustrates the graphical representation of dry substance amounts (%) of ice cream samples.

FIGURE 2 illustrates the graphical representation of the pH values of ice cream samples.

FIGURE 3 illustrates the graphical representation of total phenol amounts on ice cream samples.

FIGURE 4 illustrates the viscosity-shear rate graph of ice cream samples that do not contain probiotics but contain Oleaster at various rates.

FIGURE 5 illustrates the shear stress-shear rate graph of ice cream samples that do not contain probiotics but contain Oleaster at various rates.

FIGURE 6 illustrates the viscosity-shear rate graph of ice cream samples that contain probiotics and Oleaster at various rates.

FIGURE 7 illustrates the shear stress-shear rate graph of ice cream samples that contain probiotics and Oleaster at various rates.

Description of Reference Numerals

NUMBER Reference Name

K Conventional Ice Cream - Control Sample

KP Control Sample with Probiotics

YI Sugar-Free Ice Cream Containing 20% Oleaster

IYP Sugar-Free Probiotic Ice Cream Containing 20% Oleaster

ISY Sugar-Added Ice Cream Containing 10% Oleaster

ISYP Sugar-Added Probiotic Ice Cream Containing 10% Oleaster

SIY Sugar-Free Ice Cream Containing 10% Oleaster

SIYP Sugar-Free Probiotic Ice Cream Containing 10% Oleaster Detailed Description of the Invention

The present invention is dietary and probiotic ice cream, wherein it comprises Oleaster powder as a source of prebiotics and probiotic bacteria.

The present invention comprises milk and/or milk derivative {cream or milk powder or a mixture thereof}, Oleaster powder, probiotic bacteria, emulsifier, and stabilizer. Said ice cream formulation may optionally contain sugar.

The inventive formulation comprises; milk and/or milk derivative in a range between 65% to 89% by weight, sugar in a range between 0% to 10%, Oleaster powder in a range between 10% to 20%, emulsifier in a range between 0.5% to 1%, and stabilizer in a range between 0.5% to 1%.

The present invention preferably comprises lecithin as an emulsifier and sahlep as a stabilizer.

The probiotic used in the present invention is bacteria. The present invention comprises said probiotic bacteria at a trace amount, wherein it is at least 10 ^s cfu/g. Bacteria are added not on the basis of volume or weight, but rather based on the count of bacteria present in the g of the ice cream. The composition of the ice cream does not change as the amount added is very low by weight/volume. In other words, the change in the weight of the formulation is negligible. The inventive ice cream preferably comprises Lactobacillus plantarum bacteria.

Oleaster powder is used for the first time as a source of dietary fibers and prebiotics in ice cream. It may be used in ice cream as a substitute for milk powder and/or sugar. Since Oleaster powder contains approximately 20-25% of raw dietary fibers, it serves as a source of prebiotics and reduces the total calorie value of ice cream once added thereto. Moreover, it may be used as a sugar substitute at a relative amount in ice cream due to the sugars it contains.

Despite the fact that adding probiotic bacteria was disclosed in previous patent applications and studies, they are used for the first time in an ice cream formulation in combination with Oleaster which serves as a source of probiotics. When probiotic bacteria reach the intestines, they adhere thereto and perform various activities that may be beneficial for human health.

Milk is the main ingredient and the primary raw material of ice cream.

Granulated sugar is another main ingredient of regular ice cream and added to the formulation in order to sweeten the ice cream. This particular ingredient is removed from the ice cream composition partially or completely as per the scope of the present invention.

Skimmed milk powder is yet another main ingredient of regular ice cream, wherein it is used in order to increase the dry substance rate of ice cream. This particular ingredient is removed from the ice cream composition partially or completely as per the scope of the present invention.

Stabilizer (sahlep) is yet another main ingredient of regular ice cream, wherein it is used in order to stabilize and thicken the ice cream and to prevent it from releasing the water content thereof.

Being yet another one of the main ingredients of regular ice cream, emulsifier (lecithin) is used as an intermediate phase between water and fat phases. Milk cream is yet another one of the main ingredients of regular ice cream, wherein it is added to ice cream in order to adjust the fat rate of ice cream according to quantities defined in the respective regulation.

Milk, sugar, milk powder, stabilizer, emulsifier, and cream are the main ingredients of the conventional Maras ice cream produced via the traditional method. Even if the respective quantities of these ingredients vary in the formulation, these particular ingredients must be used in the production process of high-quality ice cream. The present invention envisages adding two additional components to ice cream. Said two additional components include Oleaster powder as a source of prebiotics and sugar and probiotic bacteria which live in the gut flora and of which positive effects on human health are proven. Oleaster (prebiotic) included in the composition of the present invention is an ingredient that not only supports the development of probiotic bacteria but also functions as a dietary fiber. Therefore, when the ice cream formulation comprises Oleaster at an amount in a range between 10% and 20% by weight, and when it is added to ice cream in combination with probiotic bacteria, it promotes the development and survival thereof. Hence, it provides a synergistic effect. Furthermore, since it is used in substitute of milk powder and/or sugar, it reduces the calorie value of ice cream, thereby avoiding any redundant costs. Furthermore, when it is used in substitute of milk powder, it increases the dry substance rate of ice cream and the water holding characteristic of the dietary fiber prevents ice cream from releasing its water content and from melting. Results obtained as per the respective studies have proven the aforementioned features .

In addition thereto, when it is used as a substitute for sugar, it provides a natural sweetness to the product via the simple sugars it contains.

The function of probiotic bacteria is that when these bacteria are ingested in significant quantities via the inventive ice cream, they attach to intestines and produce positive effects.

As the inventive symbiotic ice cream is applicable and usable in the industry, it is susceptible to industry.

The method for producing the inventive symbiotic ice cream comprises the following process steps;

Adding milk to the mixture and heating at 45°C - 50°C,

Adding at least one of stabilizer, emulsifier, and milk cream, which are the main ingredients of ice cream, to milk,

Heating the mixture to 60°C,

Adding milk powder and/or sugar,

Adding Oleaster powder with high pulp content to the mixture in a range between 10% to 20% by weight and heating it for 15 minutes at 85°C,

Cooling the prepared mixture,

Adding probiotic bacteria,

Maturing the mixture by keeping it at a temperature of 4°C for at least 12 hours.

The inventor has conducted numerous tests and experiments on the inventive probiotic and prebiotic (symbiotic) ice cream with Oleaster and aimed to prove the technical effect of the present invention.

A total of 8 ice cream samples, 4 with probiotics, and 4 without probiotics were produced for the study. Table 1 presented below provides the produced ice cream samples' ingredients in percentages.

Table 1: Ice Cream Mixture Ingredients {%)

The inventor has performed sensorial and statistical analyses on the prepared samples in order to determine the percentage of dry substance, pH value, color, total amount of phenolic content, total LAB, rheological properties, and thermal properties . Test results indicate that the dry substance rates of ice cream samples vary between 43.78% and 46.59%. Dry substance values obtained as a result of respective tests conducted on ice cream samples are provided in Table 2. Table 2: Dry Substance Amount of Ice Cream Samples (%)

Mean values calculated in this particular experiment are determined to be statistically different (p<0.05). Figure 1 illustrates the graphical representation of dry substance amounts (%) of ice cream samples. Test results indicate that the pH values of ice cream samples vary in a range between 6.38 and 5.65. Measured pH values of ice cream samples are provided in Table 3 and Figure 2.

Table 3: pH Values of Ice Cream Samples

Mean values calculated in this particular experiment are determined to be statistically different (p<0.05).

Color analysis results of ice cream samples produced by using different amounts of Oleaster, sugar, and milk powder are collectively presented in Table 4.

Table 4: L, a and b Values of Ice Cream Samples

The total phenolic contents of ice cream samples are provided in Table 5 and Figure 3.

Table 5: Total Phenolic Contents of Ice Cream Samples Mean values are statistically different from one another (p<0.05). Data obtained as a result of the total phenolic content analysis indicate that obtained results are similar to one another in samples containing the same amount of Oleaster. Moreover, it is observed that adding probiotics causes an increase in the total phenolic content (Figure 3).

Total LAB count results obtained as a result of respective analyses performed on ice cream and mixture samples are provided in Tables 6 and 7.

Table 6: Lactobacillus plantarum ssp. Counts in Ice Cream Mixture Samples

Mean values are determined to be statistically different from one another (p<0.05).

Table 7: Lactobacillus plantarum ssp. Counts in Ice Cream Mixture Samples

Figure 4 and Figure 5 illustrate the rheological properties of four different ice cream samples containing Oleaster. In Figure 4, when the viscosity-shear rate graph of ice cream samples that do not contain probiotics, but contain Oleaster at various rates is examined; it can be said that all curves decrease based on the increasing shear rate of all curves. Ice cream is a type of food that features non-Newtonian shear characteristics. In view of said graph, it is observed that four ice cream varieties feature non-Newtonian shear characteristics .

Viscosity is one of the most important properties of an ice cream mixture. The mixtures are required to have a certain viscosity value in order to retain the air fed into the ice cream via the capability of being battered.

Shear stress is the type of stress that ensures the mutual transmission of molecules. Velocity gradient indicates the transmission rate of a molecule; therefore, it is also referred to as the shear velocity. As can be seen in the respective graph, shear stress increased slightly based on the increase in the shear rate, and subsequently, it followed a decreasing curve. Initially, the sugar-free ice cream sample containing 20% Oleaster denoted by YI reference had the highest shear stress. Following a certain increment in the shear rate, the sample that showed the highest shear stress was the sugar-free ice cream sample containing 10% Oleaster denoted by SIY reference. The sample that had the lowest shear stress is the classic ice cream sample denoted by the K reference designator.

Figures 6 and 7 illustrate the rheological properties of four different ice cream samples containing both Oleaster and probiotics .

In view of the graph illustrated in Figure 6, it can be said that all curves decrease based on the increasing shear rate. Such a decrease is expected since ice cream is a type of food that features non-Newtonian shear characteristics. Considering said graph, it is observed that four ice cream varieties show non-Newtonian shear characteristics. Furthermore, it can be concluded that adding probiotics do not cause any changes in the flow characteristics.

Viscosity increases as the amount Oleaster added to ice cream samples increases. The sugar-free probiotic ice cream sample containing 20% Oleaster denoted by IYP reference had the highest viscosity value compared to other samples. The reference sample denoted by KP (control sample with probiotics) is determined to have the lowest viscosity value. These results are similar to ice cream samples that do not contain probiotics. In view of plotted graphs, it is observed that adding probiotics to the ice cream formulation yields no negative results. Consequently, it can be said that the rate of Oleaster added to ice cream formulation is the main parameter affecting the viscosity.

The shear stress-shear rate graph plotted for ice cream samples that contain probiotics was similar to the shear stress-shear rate graph of ice cream samples that do not contain probiotics. Similarly, a sugar-free probiotic ice cream sample containing 20% Oleaster denoted by IYP reference was the sample that had the highest initial shear stress. A change is observed based on the increase of shear rate. The control sample with probiotics was determined to be the sample that had the lowest shear stress. Significant differences are observed between the samples. It can be concluded that these differences are stemming from the varied rates of added substances. Consistency is one of the parameters affecting the shear stress. Consequently, the dense structure of added Oleaster is believed to have certain effects on the obtained results. When the plotted graphs are examined, no significant difference was observed between samples that contain probiotics and samples that do not. It can be said that the addition of probiotics has no negative effects on overall rheological properties . Table 8 presents the melting behavior values of ice cream samples both with and without probiotics measured by using the Mettler Toledo DSC melting point determination device.

Table 8: Melting temperature parameters of ice cream samples with and without added probiotic. Sensory analysis of ice cream samples was conducted with a 20- person panelist group and a hedonic scale was applied to samples .

Analysis results indicated that;

Dry substance rates of ice cream samples vary between 43.78% and 46.59%. An increase in dry substance amount was observed when sugar is used as a substitute for Oleaster. It is believed that this emanates from the water content of Oleaster. It is further concluded that, adding probiotics do not induce any significant changes in the dry substance rate (p<0.05).

Moreover, the total amount of dry substance that is required to be present in Semi-Skimmed Ice Cream is at least 31% in accordance with the Turkish Food Codex Communique (Communique No.: 2004/45). Results of respective studies conducted in this regard demonstrated that the total amount of dry substance was 44.77% on average in samples that do not contain probiotics.

Whereas, it was determined to be 45.2% on average for samples that contain probiotics. Obtained results are in accord with the respective communique as they are above the lower limit value defined in the Turkish Food Codex Ice Cream Communique.

Respective test results indicate that the pH values of ice cream samples vary in a range between 6.38 and 5.65. In view of the data obtained as a result of pH analysis, it is concluded that adding probiotics induces no significant changes in pH values. In an overall evaluation, it is observed that the pH value of the ice cream decreases based on the increment of the rate of Oleaster used in the production process of ice cream. This is believed to emanate from the acidic content of Oleaster fruit.

Color analyses show that Id values of ice cream samples decrease as the amount of Oleaster increases in ice cream. The decrease in L* values were considered to be statistically significant among ice cream samples (p<0.05).

Moreover, the effect produced by the addition of Oleaster- sugar-milk powder on a* and b* values of ice cream samples was considered to be statistically significant (p<0.05) As the amount of Oleaster increases, b* values of ice cream samples also increase. This is believed to emanate from the color of Oleaster fruit.

Statistical analyses indicate that total phenolic content is significantly affected by the amount of Oleaster content added to ice cream samples (p<0.05). According to the total phenolic content analysis, obtained results are similar to one another in samples containing the same amount of Oleaster. Moreover, it is observed that adding probiotics causes an increase in total phenolic content.

Probiotic bacteria count of ice cream samples varies in a range between 7.24 to 7.43 loglO cfu/g. As a result of this study, probiotic live cell counts in samples were determined to be within the required limits. It is observed that ice cream samples bear probiotic properties in terms of probiotic microorganism density. Probiotics are desired to maintain their survival throughout the storage period. This particular analysis, which was performed in order to understand whether the probiotics continue maintaining vitality or not needs to be repeated on specific days of the storage period.

When the rheological analysis results are examined in general, no significant difference was determined between the samples that contain probiotics and samples that do not. It can be said that the addition of probiotics has no negative effects on overall rheological properties.

Thermal properties of ice cream samples were also examined and melting temperatures and enthalpy values thereof were determined. It is believed that Oleaster has a high water- holding capacity and that its addition to ice cream reduces the amount of freezable water content. Moreover, DSC analysis was performed in a temperature range between -20 and 25 °C. It is believed that using a wider testing temperature range will allow for achieving melting temperature and enthalpy values of sugar-free ice cream sample containing 20% Oleaster denoted by YI reference and sugar-free probiotic ice cream sample containing 20% Oleaster denoted by IYP reference.

Results of sensory analyses showed that the acceptability of ice cream samples obtained is higher when Oleaster powder is used in substitution for sugar or milk powder, whereas ice cream samples have low sensory acceptability when Oleaster is used in substitution for both sugar and milk powder. Furthermore, the presence of probiotic bacteria did not affect the acceptability of ice cream samples.

When the samples used in respective studies and experiments are compared, it is concluded that a symbiotic ice cream that features high bioactivity and functional properties, that is rich in dietary fibers, has a low-calorie value, higher melting point (that melts slower) and that is organoleptically acceptable is produced through the addition of Oleaster powder (with prebiotic properties) and probiotic bacteria thereto.