Antioxidant capacity of alcoholic beverages based on infusions from non-traditional spicy-aromatic vegetable raw materials

Introduction. The aim of the study is to determine the antioxidant capacity of aqueous-alcoholic infusions using non-traditional spicy-aromatic raw materials in the technology of alcoholic beverages. Materials and methods. Antioxidant ability of infusions of spicy-aromatic plants: Perilla frutescens ; Elsholtzia stauntonii Benth ; Artemisia abrotanum ; Monarda didyma ; Agastache foeniculum ; Satureja hortensis ; Ruta graveolens ; Nepeta transcaucasica Grossch was determined by redoxmetry and pH-metry; sensory evaluation – by expert method; the results of mathematical and statistical processing – by the method of linear Pearson correlation. Results and discussion. The minimum theoretical value of redox potential ( RP ) for plant aqueous-alcoholic infusions was obtained, which has a value from 228.0 mV ( Satureja hortensis ) to 260.4 mV ( Agastache foeniculum ). The actual measured RP of infusions was established – from 117 mV ( Elsholtzia stauntonii Benth ) to 134 mV ( Nepeta transcaucasica Grossch ). The hydrogen index for aqueous-alcoholic infusions from spicy-aromatic raw materials has a value of 6.66 units pH ( Agastache foeniculum ) to 7.20 units pH ( Satureja hortensis ). Aqueous-alcoholic – taste – –


Introduction
One of the important directions of food industry development is improvement of taste, aroma of food, preservation (or addition) of nutritional value of the final product (Dubovkina I. et al., 2019;Kuzmin et al., 2016;Kuzmin et al., 2017) [1][2][3].
Beverages are rich sources of natural bioactive compounds such as carotenoids, phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins and terpenoids, among others (Ruiz-Ruiz et al., 2020; Naithani et al., 2006) [25,26]. Of particular interest in the production of alcoholic beverages is a spicy-aromatic raw material that exhibits antioxidant and tonic properties (Vergun et [30][31][32][33][34]. RP is an important indicator of the biological activity of solutions (Kuzmin O. et al., 2016;Merwe et al., 2017) [2,35]. It characterizes the deviation from the ionic balance of free electrons in a liquid medium. Changing the concentration of free electrons leads to a change in its electron charge and, accordingly, the RP. If the RP is positive, it indicates the oxidizing ability of the solution, negative indicates recovery ability. The value of RP allows to estimate the energy of processes, that is, characterizes the activity of ions in redox reactions (Bahir, 1999;Priluckij, 1997) [36,37]. Therefore, in order for the human body to optimally use in the exchange processes aqueous-alcoholic mixtures and food, the RP values must correspond to the RP values of the internal environment of the organism, or have more negative values (Bahir, 1999) [36].
But among all the useful properties, the main thing will be to change the redox reactions (Priluckij, 1997) [37]. Redox reactions affect the ratio of energy to support homeostasisrelativity of dynamic constancy of composition and properties of internal environment and stability of basic physiological functions of an organism. This ensures the vital activity of any organism. The magnitude of this rate depends on the ratio and concentration of oxidized and reduced substances in the body, including substances coming from food and beverages, so one of the main factors in the regulation of redox reactions is the redox potential (Kuzmin O. et al., 2016;Bahir, 1999;Priluckij, 1997) [2,36,37].
These circumstances determine the relevance of this work, which is to develop aqueousalcoholic infusions of vegetable raw materials in the technology of alcoholic cocktails for restaurants. Creating alcoholic cocktails with reduced toxicity through the introduction of spicyaromatic infusions with antioxidant properties, allows restaurant establishments to create new products, which favorably differentiates them from competitors, creating a favorable image of the institution, which cares for the protection of consumers.
The purpose of the work is to develop the scientific bases of antioxidant activity of aqueous-alcoholic infusions from vegetable raw materials and to identify the most promising plants as sources of natural antioxidants in the creation of alcoholic beverages.
It is necessary to solve the following problems: − To substantiate the prospect of using aqueous-alcoholic infusions from vegetable raw materials in the production of alcoholic beverages; − To establish the value of the restorative capacity of aqueous-alcoholic infusions from vegetable raw materials; − To develop statistics on the frequency of values in a certain range of the data obtained during sensory evaluation and physicochemical values; − To carry out mathematical and statistical analysis of indicators of aqueous-alcoholic infusions and establish internal correlation; − Identify the most promising sources of natural antioxidants for use in alcoholic beverage technology.

Materials
The study used plant raw materials that are allowed to be used in the production of alcoholic beverages. In the M.M. Gryshko National Botanic Garden of NAS of Ukraine was created new cultures of spicy-aromatic plants, which became the subject of these studies (Rakhmetov, 2011) [38].
The extracts should meet the requirements on sensory evaluation ( Table 1). The extracts must meet the requirements by physicochemical parameters (Table 2). The inherent vegetable raw materials from which they are made, without the foreign taste and odor  Aqueous-alcoholic infusionsemi-finished product, which is prepared by extraction of raw materials in aqueous-alcoholic solution with a strength of 40 %. The static method of extraction is called maceration. The tested aromatic raw material (dry) was infused in a aqueous-alcoholic mixture in this work.

Description of research procedure
The first stagethe preparation of infusions. Plant raw materials were minced into a size of 3x3 mm (Figure 2), suspensions of 4 g were placed into the glass bottles, were filled by 100 ml of alcohol solvent with volume fraction of rectified ethyl alcohol 40 %. The resulting infusions were cooled to 20 °C for 7 days, stirring periodically. Next, the infusions were filtered and studies were performed to determine the indicators of active acidity, which was measured on a pH meter in the mode of pH measurement with a combined glass electrode. The RP was measured in the potential measurement mode with a combined redoxmetric platinum electrode.

Methods for determining antioxidant capacity.
To evaluate the antioxidant properties of the obtained aqueous-alcoholic plant infusions, the method (Priluckij, 1997) [37], based on the difference of RP in inactivated inorganic solutions and complex biochemical media. The main criteria of this method were its clarity, simplicity, specificity, reproducibility of results and efficiency. A number of researchers also emphasize that method allows to determine the total antioxidant activity of liquid products, including in total in a complex mixture, and multifunctional antioxidants (Kuzmin et al., 2016) [2].
Formula (1) holds for inactivated inorganic solutions in equilibrium. This formula links the active acidity of the pH and the RP (Priluckij, 1997) [37]: where Ehminthe minimum theoretically expected value of the RP; рНactive acidity of the test solution.
Acquired RP values were compared with actual measurements of Ehact solution. Тhe change of the RP toward the recovery energy (RE) was determined by the formula: where REthe shift of RP to the side of recovered meanings (resilence); Ehminminimal theoretically expected meaning of RP; Ehactactual measured RP.
Mathematical and statistical methods. Pearson correlation coefficient measures the strength of the linear association between variables. Each variable should be continuous, random sample and approximately normally distributed. There are many rules of thumb on how to interpret a correlation coefficient, but all of them are domain specific. For example, here is correlation coefficient (Table 3) interpretation for behavioral sciences offered by Hinkle et al., 2003 [39].

Table 3 Correlation coefficient interpretation
The correlation coefficient can take a range of values from +1 to -1. Positive correlation coefficient means that if one variable gets bigger, the other variable also gets bigger, so they tend to move in the same direction. Negative correlation coefficient means that the variables tend to move in the opposite directions: If one variable increases, the other variable decreases, and vice-versa. When correlation coefficient is close to zero two variables have no linear relationship (Hinkle et al., 2003;Shendrik et al., 2019) [39,40].

Sensory evaluation
The results of sensory evaluation (Kuzmin et al., 2017) [3] of the obtained infusions on the extractant are presented in the Table 4 and Figures 3.   [19,20] of which are presented in the Table  5.   The minimum theoretical value of RP (Ehmin) for plant aqueous-alcoholic infusions (Priluckij, 1997) [37] was obtained, which has a value from 228.0 mV (Satureja hortensis) to 260.4 mV (Agastache foeniculum). The actual measured RP of infusions (Ehact) was establishedfrom 117 mV (Elsholtzia stauntonii Benth) to 134 mV (Nepeta transcaucasica Grossch). The hydrogen index for aqueous-alcoholic infusions from spicy-aromatic raw materials has a value of 6.66 units pH (Agastache foeniculum) to 7.20 units pH (Satureja hortensis).
Aqueous-alcoholic infusions from vegetable raw materials and a volume fraction of ethanol of 40% have the value of regenerative capacity (recovery energy -RE) in the range from RE 100.0 mV (Nepeta transcaucasica Grossch) to RE 138.2 mV (Ruta graveolens). For the restaurant business in the manufacture of alcoholic beverages are promising aqueousalcoholic infusions of Ruta Gravelens and Nepeta transcaucasica Grossch, which received increased antioxidant characteristics RE 138.2 mV and RE 100.0 mV, respectively, and positive sensory evaluation (S.e.) 9.57 and S.e. 9.69 points.
The prescription composition of alcoholic beverages may include aqueous-alcoholic infusions with a mass fraction of extractivesup to 60 g/100 cm 3 (liqueur).

Determination of Pearson's linear correlation
According to the physicochemical and sensory evaluation, mathematical and statistical analysis (Hinkle et al., 2003;Shendrik et al., 2019) [39,40] was performed in the Pearson correlation matrix (Table 6). According to the obtained matrix 6*6, it was found that of the 6 indicators (t, pH, Ehmin, Ehact, RE, S.e.), only 4 indicators are statistically significant. As a result of research it was found that physicochemical parameters (t, pH, Ehmin, Ehact, RE) are statistically insignificant for sensory evaluation (S.e.), because the correlation coefficient is very weak (r=0.0-0.3). Also, a weak (r=0.3-0.5) and very weak (r=0.0-0.3) relationship is observed between temperature (t) and other physicochemical and sensory evaluation. The range of values with very high correlation (r=0.9-1.0) includes the following indicators: pH, Ehmin, Ehact, RE. Figure 8 shows the graphical dependence of pH on Ehmin. It was found that the pH is in the range of 6.66-7.96, and Ehmin 182.4-260.4 mV. According to the obtained equation, at a pH value of 7.00 Ehmin is 240 mV. When the pH value changes by 1 (pH 8.00), the Ehmin decreases by 60 mV (Ehmin 180 mV). That is, the relationship between Ehmin and pH is very high, because r=-1, because it is inversely correlated, which leads to an increase in pH to a decrease in the level of Ehmin. Based on the research, it was found that the addition to the aqueous-alcoholic system with a weakly alkaline environment of vegetable spicy-aromatic raw materials, which leads to acidification and reduction of the pH level in the neutral environment (pH 6.66-7.20). It was found that Ehact is in the range from 117 to 180 mV, and the pH is 6.66-7.96. At the value of Ehact 120 mV, the pH level is 6.8. If you increase the pH to by one to 7.8 then the value of Ehact will be 159 mV, i.e. Ehact will increase by 39 mV. This is due to the fact that there is a very strong interdependence between the variables Ehact and pH (r=0.8). As the pH value increases, the Ehact index increases.
It was found that RE is in the range from 2.4 to 138.2 mV, and the pH is 6.66-7.96. When the value of RE 132 mV, the pH level is 6.8. If you increase the pH by one to 7.8, the value of RE will be 32 mV. Increasing the pH per unit from 6.8 to 7.8 leads to a decrease in RE by 100 mV. This is due to the fact that there is a very strong interdependence between the variables RE and pH (r=-0.9). As the pH value increases, the RE decreases. The general graph of the three most correlation-significant physicochemical parameters is shown in Figure 14. In volumetric form, it is seen that some points (Ehact, RE, Ehmin) are as close as possible to the surface, i.e. there is a very strong correlation between them. The farther the points are from the surface, the weaker the relationship.  The histogram of the distribution of sensory evaluation is shown in Figure 15. Numerical values are divided into ranges with an interval of 0.5, starting from 9.45 to 9.70 points. Only 5 ranges and the same number of columns. The maximum frequency is typical for 4 ranges in the range 9.50-9.70 points -8 values of the variable. The lowest frequency has the range 9.45-9.50 points, which got 1 value of the variable.  Figure 16 shows the distribution of pH values, the range of which is divided into 3 columns. It is established that 9 data elements lie in the range of pH values 6.6-8.0. The highest frequency 5 is the range of pH values 7.0-7.2, 3in the range of pH values 6.6-6.8, and only 1in the range 7.8-8.0, which is the lowest frequency.  Figure 17 shows the histogram of RP (Ehmin). The x-axis is divided into 5 ranges ranging from 180 to 270 mV. According to the values of the elements in the data set, only 5 columns. The maximum frequency is typical for the range 230-240 mV, which includes 3 elements. The lowest frequency is characteristic for the ranges 180-190 mV, 260-270 mV, which includes 1 element.
The value of the histogram (Ehact) ( Figure 18) is divided into 4 ranges, starting with 110 and ending with 180 mV. The maximum repetition rate is typical for the range 110-120 mV and 130-140 mV, each includes 3 values. The lowest frequency of the ranges is 170-180 mV, which includes 1 element. Figure 19 shows a histogram of RE, which includes 4 ranges starting from 0 to 140 mV. The maximum frequency, which consists of 4 elements, belongs to the range 120-140 mV, and the lowest 0-20 mV and 80-100 mV, which include 1 element.
Histograms allow you to develop statistics on the frequency of values in a certain range. They are a generalized view of the data obtained during sensory evaluation and physicochemical values (Shendrik et al., 2019) [40].
Based on mathematical and statistical analysis, it was found that physicochemical parameters (pH, Ehmin, Ehact, RE) are statistically insignificant for sensory evaluation (S.e.) and infusion temperature (t). The range of values with very high correlation (r=0.9-1.0) includes the following indicators: pH, Ehmin, Ehact, RE.

Development of recipes of alcoholic beverages
On the basis of the obtained results, it was established that the maximum values of RP have extracts of Ruta graveolens and Nepeta transcaucasica Grossch. These extracts were used in the preparation of cocktails, the recipes of which are presented in Table 7-8.    [19][20][21][22][23][24][27][28][29], will help to increase the immunity of the human body, improve the metabolism, positively affect the cardiovascular system, in addition it increases the consumer properties and will allow to reduce the cost of the finished product.

Conclusions
1. It is established that one of the promising ways of forming consumer properties and expanding the range of alcoholic products is the use of new types of spicy-aromatic plants, which include biologically active substances. Such substances improve the sensory evaluation of beverages, contribute to the promotion of human health (antioxidant effects, enhancing redox reactions). 2. Experimental studies show that all aqueous-alcoholic infusions of aromatic origin contain antioxidant systems. It was found that the recovery value of all the tested extracts is positive and ranges from 100.0 to 138.2 mV. 3. Histograms allow you to develop statistics on the frequency of values in a certain range.
They are a generalized view of the data obtained during sensory evaluation and physicochemical values. 4. Based on mathematical and statistical analysis, it was found that the infusion temperature (t) has a statistically insignificant effect on physicochemical parameters (pH, Ehmin, Ehact, RE), which have a statistically insignificant effect on sensory evaluation (S.e.). The range of values with very high correlation (r=0.9-1.0) includes the following indicators: pH, Ehmin, Ehact, RE. 5. Improvement of the technology of alcoholic cocktails by adding spicy-aromatic aqueous-alcoholic infusions allows to increase the redox properties of the product, increases consumer properties and reduces the cost of the finished product.