KR100950955B1 - Method for determining adulteration of honey via analysis on dynamic viscoelastic properties during heating and cooling processes - Google Patents

Abstract

The present invention relates to a method for determining the authenticity of honey through dynamic viscoelastic analysis in the heating and cooling process, and more specifically, -15 ℃ to about the analysis honey and the reference honey contrasted with the analysis honey as the authenticity determination target Measuring dynamic viscoelastic property values in a temperature range of −5 ° C .; And falsely discriminating the analyzed honey when the discriminated value obtained by dividing the dynamic viscoelastic characteristic value of the reference honey by the viscoelastic characteristic value of the analyzed honey exceeds 1.5.

According to the present invention, unlike the chemical honey authenticity determination method that requires expensive equipment, professional personnel and long-term analysis and involves structural destruction at the level of molecular structure, it is accurate and easy by a simple and inexpensive structure nondestructive dynamic viscoelasticity measuring method. It is possible to determine the authenticity of honey.

Honey, Dynamic Viscoelastic

Description

{Method for determining adulteration of honey via analysis on dynamic viscoelastic properties during heating and cooling processes}

The present invention relates to a method for determining the authenticity of honey through dynamic viscoelastic analysis during heating and cooling, and more specifically, requires expensive equipment, professional personnel and long-term analysis, and involves chemical destruction at the molecular level. Unlike the honey authenticity discrimination method, the present invention relates to a honey authenticity discrimination method capable of accurately and easily determining the authenticity of honey by a relatively simple and inexpensive structure nondestructive dynamic viscoelasticity measuring method.

Honey means that honey is collected by honey from honey and stored in honeycomb, and it does not include additives such as Hwagun, royal jelly, sugars, and sweeteners after harvesting (Food Code, Korea Food Industry Association). Honey contains sugars such as glucose and fructose as well as ideal nutrients such as vitamins, proteins, minerals, and amino acids that are unique to pollen. It is known to show excellent efficacy in promoting children's development and the like, and fructose, which is a main ingredient in honey, is consumed in the food industry as a sweetener because it has a fast absorption rate and high sweetening effect compared to sucrose.

In the past, various chemical analysis methods were mainly used for quality evaluation and authenticity of honey. In view of the diversity of honey, taxonomic classification of bees, seasonal factors and regional differences, the quality of honey is evaluated by one chemical analysis method. There are limitations in accurately and authenticating the authenticity. In addition, these chemical analytical methods require expensive equipment, complexity of the analytical method, continuous management of the analyzer, high cost, long analysis time, and the structural destruction at the molecular level. It implies.

On the other hand, the viscoelastic properties of honey, like other fluid foods, are important in practical applications with regard to handling, storage, processing and transport. In general, the viscoelastic change of honey varies depending on the moisture content, sugar content, temperature and the content and size of the crystals. In particular, the effect of temperature on the viscoelasticity of honey needs to be further studied, since this viscoelasticity is greatly influenced by a wide range of temperature changes that occur during processing and storage.

Most foods exhibit so-called viscoelastic properties that exhibit some viscous and elastic behavior. The dynamic viscoelasticity of various fluid foods is mainly measured by small-amplitude oscillatory shear measurement (SAOS). The measurement results provide valuable viscoelastic data for the various foods without destroying the structure of the fluid food. Various viscoelastic data derived from SAOS measurements, for example storage modulus G '(storage modulus) associated with the elastic properties of the molecule as a measure of stored energy or viscous property of the molecule as a measure of lost energy Data such as loss modulus (G "), which is associated with, have a very high correlation with other chemical data such as NMR data.

Therefore, viscoelastic data, such as SAOS measurement, is a non-destructive measurement technique that can be performed within the viscoelastic linear range without causing structural damage to the sample, thereby enabling the correlation between viscoelastic data and molecular structure, and ii) high cost. Because it does not require long-term analysis or equipment, it enables simple and quick sample analysis. Iii) It can provide experiments in a wide range of frequency bands and provide differentiated information that cannot be obtained by other experimental methods. Its usefulness is recognized.

Low temperatures have traditionally been known to cause crystallization of honey, which results in a change in dynamic viscoelastic properties, which has been reported to be affected by the moisture content or sugar composition of honey. Specifically, Sopade et al. (Sopade PA, Halley PJ, D'arcy BR, Bhandari B, Caffin N. Dynamic and steady-state rheology of Australian honeys at subzero temperatures. J. Food Process Eng. 27: 284-309 (2004) ) Investigated the viscoelastic properties associated with liquid-solid phase transitions over a range of temperatures below 0 ° C for various Australian honeys. Therefore, in theory, the dynamic viscoelastic properties of honey are greatly influenced by the crystallization of sugar components present in honey, so it is possible to predict and control the quality of honey due to the different crystallization process of honey at low temperatures.

On the other hand, relatively inexpensive high fructose corn syrup or invert sugar is widely used in the manufacture of fake honey, and considering that honey is basically a mixture of sugar and water, other sugars The addition of components results in a change in dynamic viscoelastic properties. Therefore, the necessity of analyzing the dynamic viscoelastic characteristics as a method of authenticity of fake honey including invert sugar is increasing.

The present invention has been made to solve the problems of the prior art, the problem to be solved by the present invention is a simple and inexpensive structure non-destructive dynamic viscoelasticity measuring method can accurately and easily determine the authenticity of honey honey It is to provide a determination method.

In order to achieve the above object,

Measuring dynamic viscoelastic property values in the temperature range of -15 ° C to -5 ° C for the analysis honey to be authenticity discriminated and the reference honey compared with the analysis honey; And

When the determination value obtained by dividing the dynamic viscoelastic property value of the reference honey by the viscoelastic property value of the analysis honey exceeds 1.5, it provides a method for determining the authenticity of honey including falsely discriminating the analysis honey.

According to an exemplary embodiment of the present invention, when the determination value exceeds 1.2, the analytical sample may be falsely determined.

According to another preferred embodiment of the present invention, the dynamic viscoelastic property value can be measured during the heating process from -15 ° C to -5 ° C.

According to another preferred embodiment of the present invention, the dynamic viscoelastic property value can be measured during the cooling process from -5 ℃ to -15 ℃.

According to another preferred embodiment of the present invention, the dynamic viscoelastic property value is a storage modulus G '(storage modulus), a loss modulus G "(loss modulus), a complex viscosity η ^* or tanδ (G" / G' ratio) Can be.

According to another preferred embodiment of the present invention, the viscoelastic property values of the reference honey and the analysis honey may be an average value of the viscoelastic property values obtained by changing the temperature in units of 1 ° C in the temperature range of -15 ° C to -5 ° C. have.

According to another preferred embodiment of the present invention, the heating rate and cooling rate of the heating process and cooling process may be 1 ° C / min.

According to the present invention, it is possible to accurately and easily determine the authenticity of honey by a simple and inexpensive structure nondestructive dynamic viscoelasticity measuring method.

Hereinafter, the present invention will be described in more detail.

Honey is the most complex sugar mixture in natural foods and contains sugars such as glucose, fructose, sucrose, maltose and isomaltose. Among these sugars, glucose and fructose make up the largest portion of the constituents of honey, and make up 70 to 80% of the total sugar constituting the honey. In particular, glucose is a major causative agent of honey crystallization. In general, the rate of honey crystallization varies depending on the processing and handling of honey and the type of honey, and is affected by the sugar composition of glucose-based honey. It is known to receive. For example, honey with a glucose / water ratio of less than 1.7 may exist in the liquid state for long periods of time, whereas it rapidly crystallizes when the ratio exceeds 2.1.

On the other hand, when artificial sugar components, such as invert sugar, are mixed with real honey, physical properties differ from pure real honey because of differences in structural internal bonds between sugar components constituting honey. In particular, the inventors have found that in certain low temperature ranges below 0 ° C., pure honey and inverted honey added with invert sugar show significant differences in dynamic viscoelastic properties, and based on this fact, it is simple and inexpensive. The purpose of the present invention is to provide an accurate and easy way to determine the authenticity of honey by structural nondestructive dynamic viscoelasticity measuring method.

Specifically, the present invention comprises the steps of measuring the dynamic viscoelastic property values in the temperature range of -15 ° C to -5 ° C for the analysis honey to be the authenticity determination and the reference honey contrasted with the analysis honey; And falsely discriminating the analyzed honey when the discriminated value obtained by dividing the dynamic viscoelastic characteristic value of the reference honey by the viscoelastic characteristic value of the analyzed honey exceeds 1.5.

Figure 1 shows the graph of the storage modulus G '(storage modulus) value with respect to the reference honey as pure real honey, measured during the cooling process in the range of 0 ℃ to -14 ℃, along with the reference honey: The storage modulus G '(storage modulus) values for the mixing ratios of 5: 5, 9: 1, 6: 4, 7: 3 and 8: 2 are shown. .

Referring to FIG. 1, the storage modulus (G ') value of the reference honey and the mixed honey does not show a significant difference in the temperature range of about 0 ° C. to about −5 ° C., but at a temperature range of about −5 ° C. or less. It can be seen that the values show a sharp difference. In addition, when the temperature is less than about -15 ℃, the viscosity of the honey rises rapidly, which may make it impossible to measure the dynamic viscoelasticity, the most suitable temperature range for measuring the dynamic viscoelastic properties of the reference honey and mixed honey is -5 It can be said that it is -15 degreeC. In other words, in the present invention, a predetermined low temperature range, for example, an analytical honey suspected of being a false honey mixed with invert sugar and a reference honey that provides a criterion for determining the authenticity of the analytical honey by comparing it with the analytical honey, For example, by comparing the dynamic viscoelastic profile with temperature at -5 ° C to -15 ° C it is possible to easily determine the authenticity of the analysis honey.

In the present invention, as a means for determining the authenticity of the analyzed honey, the value of the dynamic viscoelastic characteristic value of the reference honey divided by the viscoelastic characteristic value of the analyzed honey is used, that is, a numerical value. This discrimination value will be "1" if the analytical honey has a dynamic viscoelastic characteristic value that is exactly the same as the reference honey that is the real honey to be compared, and if the dynamic viscoelastic characteristic value of the analytical honey is smaller than the dynamic viscoelastic characteristic value of the reference honey. Will have a value greater than 1, and vice versa. For reference, referring to FIG. 1, when the analyzed honey is fake honey to which invert sugar is added at a predetermined ratio, it is smaller than the dynamic viscoelastic property value of the reference honey in the temperature range of -5 ° C to -15 ° C. In general, the determination value has a value greater than one. In addition, when the determination value exceeds 1.5 in consideration of the dynamic viscoelastic characteristic value measurement condition or the maximum measurement error 10% resulting from the difference between the characteristic values between samples, and more preferably, the analysis honey is more than 1.2. It can be clearly determined that it is fake honey.

On the other hand, the measurement of the dynamic viscoelastic property value for determining the determination value may be measured during the cooling process from -5 ° C to -5 ° C, as shown in Figure 1, but -5 ° C as shown in Figure 2 Can be measured during the heating process from -15 ° C, in which case the heating rate and cooling rate can be 1 ° C / min.

In addition, as specific numerical values for determining the dynamic viscoelastic characteristic value, the storage modulus G ′ (storage modulus) illustrated in FIGS. 1 and 2 may be used, but is not limited thereto. In addition, loss modulus G ″, Complex viscosity η ^* or tanδ (G "/ G 'ratio) Numerical values or the like may be used.

In order to determine the authenticity of the analyzed honey, the former may be calculated by dividing the former by measuring the dynamic viscoelastic properties of the reference honey and the analyzed honey at a specific temperature in the temperature range of -5 ° C to -15 ° C. On the other hand, an average value of eleven viscoelastic properties obtained by varying the temperature in units of 1 ° C in the above temperature range may be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are not intended to limit the scope of the present invention, which will be construed as to help the understanding of the present invention.

Purchase and analysis of reference honey Preparation of honey

As the reference honey, Korean acacia honey with a water content of 19.0% purchased from a local store was adopted. To prepare analytical honey with different invert sugar content, liquid invert sugar was added to Suikers G. Lebbe N.V. (Oostkamp, Belgium). The moisture content of the liquid invert sugar was 19.0% which is the same as the reference honey. Moisture content of reference honey and invert sugar was measured by measuring the refractive index at 20 ° C. using a digital refractometer (DR-A1 Abbe refractometer; Atago Co., Tokyo, Japan). Moisture content was determined based on the table described in AOAC Method 31.119.

To prepare analytical honeys with different invert sugar content, the reference honey and invert sugar were mixed so that the weight ratios of the reference honey to invert sugar were 9: 1, 8: 2, 7: 3, 6: 4 and 5: 5. .

dynamic Viscoelastic  Measurement of characteristics

Since the dynamic viscoelastic properties of honey can be affected by the presence of crystals and bubbles, the reference honey and the analytical honey are heated at 55 ° C. for 1 hour under water bath conditions to dissolve the crystals present in the honey sample, and Bubbles were removed by slowly stirring at 30 ° C. for 48 hours using a stirrer.

The dynamic viscoelastic properties for the honey samples were obtained with a TA rheometer (AR 1000, TA Instruments, New Castle, DE) using a parallel plate system (4 cm diameter) at a 500 μm gap. 15 ° C, -10 ° C, -5 ° C and 0 ° C). Dynamic viscoelastic properties data were measured from a frequency band spanning 3% strain and a range of 0.63-48.3 rad / sec, which was 3% in the linear viscoelastic region. TA rheology to calculate storage modulus (G '), loss modulus (G "), and complex viscosity (η ^* ) and to obtain horizontal shift factors (a _T ) for time-temperature overlap (TTS) of experimental data Physical property analyzer Data Analysis Software (version VI.1.76) was used.

Each measurement was made for 2 minutes after sample loading to allow temperature equilibration to the desired temperature. The loss modulus (G ") values at -10 ° C to -15 ° C for the samples were measured only in the frequency range of 0.62-8.90 rad / sec, where the high values of the samples exceeded the limits of the TA AR1000 rheometer. Because.

Analysis of Sugar Composition

Analytical honey and 100% invert sugar with weight ratios of 8: 2 and 6: 4 of reference honey, reference honey to invert sugar, using high performance liquid chromatography (HPLC, Nanospace SI2; Shiseido Fine Chemicals, Tokyo, Japan) as a chemical reference Sugar samples (fructose, glucose and sucrose) were performed on honey samples. The HPLC column used an Asahipak-NH2P-50 250 × 4.6 mm column, a flow rate of 0.8 mL / min, and a mixture of acetonitrile and water (70:30) as the mobile phase. 1 g honey sample was dissolved in a mixture of acetonitrile and water (50:50) and transferred to a 50 mL flask. Samples were poured through a 0.45 μm membrane filter and collected in sample vials. As the sample for analysis, 20 µl of 35 ° C was used. The column eluate was monitored using a refractive index detector (RI104; Shodex, Tokyo, Japan). A standard solution containing 0.5% (w / v) of fructose, glucose and sucrose was prepared to identify and quantify each sugar component in the honey sample.

As can be seen from Table 1 below, all honey samples, except pure invert sugar, contained an excess of fructose rather than glucose, which means that the ratio of fructose to glucose is in the range of about 1.24-1.54. Means that. The content of fructose in the reference honey (48.4%) gradually decreased as the ratio of the reference honey / sugar was increased, but the glucose content (31.4%) increased. In addition, the fructose / glucose ratio decreased as the content of invert sugar increased.

Standard Honey / Per Phone Rate Glucose (%) Fructose (%) Sucrose (%) Fructose / Glucose Ratio 10/0 (reference honey) 31.4 48.4 5.74 1.54 8/2 34.4 47.3 4.55 1.37 6/4 37.3 46.2 3.42 1.24 0/10 (per phone) 46.0 42.9 Not detected 0.93

dynamic Viscoelastic  Evaluation of characteristics

The change in G 'value with temperature for the analysis honey with the weight ratio of the reference honey and the reference honey: invert sugar is 9: 1, 8: 2, 7: 3, 6: 4 and 5: 5 (FIG. 1). And FIG. 2 (heating process).

Referring to Figures 1 and 2, the reference honey with 0% content of invert sugar has a higher G 'value at the same temperature than the analyzed honeys in which invert sugar is added at a predetermined rate, and this tendency is from about -5 ° C to It can be seen that it stands out in the temperature range of -15 ° C. Therefore, it is possible to determine whether the analyzed honey is false from the degree of separation of the graph of the analyzed honey from the graph of the reference honey. In particular, the larger the difference between the Y value for the reference honey and the Y value for the analysis honey, the greater the value of the dynamic viscoelastic property of the reference honey divided by the value of the viscoelastic property of the analysis honey, that is, the greater the discrimination value and the false probability of the analysis honey. Becomes even larger.

According to the present invention, the authenticity of honey can be determined by a non-destructive method by inexpensive equipment and a simple procedure, and thus can be widely used in the manufacturing process of various foods to which honey is added.

1 is a graph showing the storage modulus (G ') storage modulus value G' (storage modulus) according to the temperature for the analyzed honey mixed with the reference honey and invert sugar during the cooling process in the range of 0 ℃ to -14 ℃.

FIG. 2 is a graph showing the storage modulus (G ') value according to the temperature of the analyzed honey mixed with the reference honey and the invert sugar measured during the heating process in the range of 0 ° C to -14 ° C.

Claims (7)

Measuring dynamic viscoelastic property values in the temperature range of -15 ° C to -5 ° C for the analysis honey to be authenticity discriminated and the reference honey compared with the analysis honey; And And falsely discriminating the analyzed honey when the discriminated value obtained by dividing the dynamic viscoelastic property value of the reference honey by the viscoelastic property value of the analyzed honey exceeds 1.5. The method of claim 1, wherein when the determination value exceeds 1.2, the analytical sample is discriminated false. The method of claim 1, wherein the dynamic viscoelastic property value is measured during a heating process from -15 ° C to -5 ° C. The method of claim 1, wherein the dynamic viscoelastic characteristic value is measured during the cooling process from -5 ° C to -15 ° C. 2. The honeycomb according to claim 1, wherein the dynamic viscoelastic property value is a storage modulus G '(storage modulus), a loss modulus G "(loss modulus), a complex viscosity η ^* or tanδ (G" / G' ratio). Authenticity determination method. The honeycomb honeycomb according to claim 1, wherein the viscoelastic property values of the reference honey and the analyzed honey are average values of viscoelastic property values obtained by varying the temperature in units of 1 ° C in a temperature range of -15 ° C to -5 ° C. Authenticity determination method. 5. The method of claim 3, wherein the heating rate of the heating process or the cooling rate of the cooling process is 1 ° C./min.

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