Method for analyzing stable hydrogen isotope ratio of non-exchangeable hydrogen in food total sugar

Abstract

The invention provides a method for analyzing a stable hydrogen isotope ratio of non-exchangeable hydrogen in food total sugar, and belongs to the field of stable isotope technology research. The method comprises the following steps: 1) selecting a sugar compound with a known stable hydrogen isotope ratio of non-exchangeable hydrogen as a working standard, fermenting, converting into ethanol, andmeasuring the hydrogen isotope ratio of ethanol in the fermentation liquor; 2) establishing delta 2H sugar non-exchangeable hydrogen = a * delta 2H ethanol + b; 3) determining the hydrogen isotope ratio of ethanol in the to-be-determined food fermentation broth; and 4) substituting the hydrogen isotope ratio of the ethanol in the to-be-detected food fermentation broth into the relation model to obtain the stable hydrogen isotope ratio of the non-exchangeable hydrogen in the to-be-detected food total sugar. The method provided by the invention is mainly used for determining the stable hydrogenisotope ratio of non-exchangeable hydrogen in food total sugar and is easy to operate, low in experimental cost, rapid in analysis, high in efficiency, safe and risk-free and is suitable for analysisand test of a large batch of honey samples.

Description

technical field

[0001] The invention belongs to the field of stable isotope technology research, in particular to a method for analyzing the stable hydrogen isotope ratio of non-exchangeable hydrogen in food total sugar. Background technique

[0002] With the improvement of people's consumption concept, food is an indispensable part of people's daily life, and the food industry is developing rapidly. Sugar-containing foods (such as honey and fruit juice) are popular among the public due to their sweet taste. However, in order to increase the sweetness of foods, some unscrupulous businesses often mix in low-cost, low-nutritional sugars that are not ingredients of the food itself.

[0003] Stable isotope distribution characteristics can indicate the source information of substances. By measuring the hydrogen isotope composition characteristics of total food sugars, it has become a research focus for scientific and technological workers in the food field to determine whether fo...

Examples

Embodiment 1

[0029] Example 1 Establishment of the δ of ethanol in fermentation broths of sugar compounds as a working standard 2 h 乙醇 Non-exchangeable hydrogen δ with sugar 2 h 糖不可交换氢 relational model

[0030] 1) Select three sugar compound working standard substances, whose δ of non-exchangeable hydrogen 2 h 糖不可交换氢 The values ​​are -125.35‰, -101.25‰ and -80.63‰ respectively; among them, the working standard sugar compound is preferably glucose, whose δ of non-exchangeable hydrogen 2 h 糖不可交换氢 Values ​​were determined by the method proposed by John Dunbar et al.

[0031] 2) Three sugar compounds used as working standards were respectively prepared into 170g / L sugar aqueous solution, after adding 0.5g active dry yeast, alcoholic fermentation was carried out at 30±0.5°C;

[0032] 3) Take the clarified liquid after the centrifugation of the fermented liquid, and measure the δ of ethanol in the fermented liquid with a gas chromatography-cracking-stable isotope ratio mass spectrometer ...

Embodiment 2

[0036] Example 2 Analysis of hydrogen isotope ratios of total sugar non-exchangeable hydrogen in acacia honey

[0037]Take a kind of acacia honey as the research object, remove the moisture in the honey by freeze-drying, and then prepare the solid powder into a 170g / L sugar aqueous solution, add 0.5g active dry yeast to the 100g solution sample for alcohol fermentation, and determine δ of ethanol in fermentation broth 2 h 乙醇测定 This process was repeated three times, and the results are shown in Table 2.

[0038] Table 2 δ of ethanol fermented by acacia honey samples 2 h 乙醇测定 Value repeatability determination results

[0039] index repeat -1 Repeat -2 repeat -3 δ 2 h 乙醇测定 (‰)

-315.88 -311.26 -310.33

[0040] The standard deviation of the results of three repeated analyzes was 2.97‰, which met the requirements of stable isotope analysis (better than 3‰).

[0041] Substitute the data in Table 2 into the relational model of Example 1, and c...

Embodiment 3

[0044] Example 3 Analysis of hydrogen isotope ratios of non-exchangeable hydrogen of total sugars in linden honey

[0045] Take 3 linden honey as the research object, remove the water in the honey by freeze-drying, and then prepare the solid powder into 170g / L sugar aqueous solution, add 0.5g active dry yeast to 100g solution sample for alcoholic fermentation , to determine the δ of ethanol in the fermentation broth 2 h 乙醇测定 values, and the results are shown in Table 4.

[0046] Table 4 δ of ethanol converted from linden honey 2 h 乙醇测定 The measurement results

[0047] index Linden Honey-1# Linden honey-2# Linden honey-3# δ 2 h 乙醇测定 (‰)

[0048] Substitute the data in Table 4 into the relational model obtained in Example 1, and calculate the δ of the non-exchangeable hydrogen of sugar 2 h 糖不可交换氢计算 values, and the results are shown in Table 5.

[0049] Table 5 δ of non-exchangeable hydrogen of sugar in Linden honey 2 h 糖不可交换氢计算 value calculati...

technical field

[0001] The invention belongs to the field of stable isotope technology research, in particular to a method for analyzing the stable hydrogen isotope ratio of non-exchangeable hydrogen in food total sugar. Background technique

[0002] With the improvement of people's consumption concept, food is an indispensable part of people's daily life, and the food industry is developing rapidly. Sugar-containing foods (such as honey and fruit juice) are popular among the public due to their sweet taste. However, in order to increase the sweetness of foods, some unscrupulous businesses often mix in low-cost, low-nutritional sugars that are not ingredients of the food itself.

[0003] Stable isotope distribution characteristics can indicate the source information of substances. By measuring the hydrogen isotope composition characteristics of total food sugars, it has become a research focus for scientific and technological workers in the food field to determine whether fo...

Examples

Embodiment 1

[0029] Example 1 Establishment of the δ of ethanol in fermentation broths of sugar compounds as a working standard 2 h 乙醇 Non-exchangeable hydrogen δ with sugar 2 h 糖不可交换氢 relational model

[0030] 1) Select three sugar compound working standard substances, whose δ of non-exchangeable hydrogen 2 h 糖不可交换氢 The values ​​are -125.35‰, -101.25‰ and -80.63‰ respectively; among them, the working standard sugar compound is preferably glucose, whose δ of non-exchangeable hydrogen 2 h 糖不可交换氢 Values ​​were determined by the method proposed by John Dunbar et al.

[0031] 2) Three sugar compounds used as working standards were respectively prepared into 170g / L sugar aqueous solution, after adding 0.5g active dry yeast, alcoholic fermentation was carried out at 30±0.5°C;

[0032] 3) Take the clarified liquid after the centrifugation of the fermented liquid, and measure the δ of ethanol in the fermented liquid with a gas chromatography-cracking-stable isotope ratio mass spectrometer ...

Embodiment 2

[0036] Example 2 Analysis of hydrogen isotope ratios of total sugar non-exchangeable hydrogen in acacia honey

[0037]Take a kind of acacia honey as the research object, remove the moisture in the honey by freeze-drying, and then prepare the solid powder into a 170g / L sugar aqueous solution, add 0.5g active dry yeast to the 100g solution sample for alcohol fermentation, and determine δ of ethanol in fermentation broth 2 h 乙醇测定 This process was repeated three times, and the results are shown in Table 2.

[0038] Table 2 δ of ethanol fermented by acacia honey samples 2 h 乙醇测定 Value repeatability determination results

[0039] index repeat -1 Repeat -2 repeat -3 δ 2 h 乙醇测定 (‰)

-315.88 -311.26 -310.33

[0040] The standard deviation of the results of three repeated analyzes was 2.97‰, which met the requirements of stable isotope analysis (better than 3‰).

[0041] Substitute the data in Table 2 into the relational model of Example 1, and c...

Embodiment 3

[0044] Example 3 Analysis of hydrogen isotope ratios of non-exchangeable hydrogen of total sugars in linden honey

[0045] Take 3 linden honey as the research object, remove the water in the honey by freeze-drying, and then prepare the solid powder into 170g / L sugar aqueous solution, add 0.5g active dry yeast to 100g solution sample for alcoholic fermentation , to determine the δ of ethanol in the fermentation broth 2 h 乙醇测定 values, and the results are shown in Table 4.

[0046] Table 4 δ of ethanol converted from linden honey 2 h 乙醇测定 The measurement results

[0047] index Linden Honey-1# Linden honey-2# Linden honey-3# δ 2 h 乙醇测定 (‰)

[0048] Substitute the data in Table 4 into the relational model obtained in Example 1, and calculate the δ of the non-exchangeable hydrogen of sugar 2 h 糖不可交换氢计算 values, and the results are shown in Table 5.

[0049] Table 5 δ of non-exchangeable hydrogen of sugar in Linden honey 2 h 糖不可交换氢计算 value calculati...

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