阅读说明：本技术 检测芒果水分组份含量的方法 (Method for detecting mango moisture component content ) 是由 谢晶 卫赛超 王金锋 许启军 于 2021-01-12 设计创作，主要内容包括：本发明涉及利用低场核磁共振成像仪检测芒果水分组份含量的检测方法,包含芒果的处理及水分含量检测步骤。对芒果进行切分、取样、包裹后冷藏待测,仪器预热后进行水膜校准,选择合适序列并确认参数,等待结果图像显示后反演处理,并记录数据。本发明能有效、便捷地表征芒果在贮藏过程中水分组分含量的变化,可用于快速评价芒果的品质变化及其鲜度特性,具有较强的实用性和商业价值。(The invention relates to a method for detecting mango moisture component content by using a low-field nuclear magnetic resonance imager, which comprises the steps of mango processing and moisture content detection. And carrying out segmentation, sampling and wrapping on the mangos, refrigerating the mangos to be tested, preheating an instrument, carrying out water film calibration, selecting a proper sequence and confirming parameters, carrying out inversion processing after a result image is displayed, and recording data. The method can effectively and conveniently represent the change of the water content of the mangos in the storage process, can be used for quickly evaluating the quality change and the freshness characteristic of the mangos, and has strong practicability and commercial value.)

1. The method for detecting the water component content of the mangoes by using the low-field nuclear magnetic resonance imager is characterized by comprising the following steps of:

(1) determining a sampling position: measuring the full length of the mango by using a ruler, determining quartering points of the flesh on two sides, and making sampling marks;

(2) and (3) mango segmentation: respectively cutting off the two sides of mango pulp in parallel with the plane of the mango stone;

(3) sampling pulp: taking the cut pulp, vertically cutting the pulp according to the sampling identification, removing the edges of the pulp at two ends, and adjusting the pulp into a cube to be tested with the length of 3-5 cm, the width of 3-5 cm and the height of 0.7-1.5 cm;

(4) wrapping with a preservative film: preparing a preservative film with the length and the width being 3 times of those of the sample to be tested, carefully wrapping the preservative film, and refrigerating the preservative film to be tested;

(5) and (3) measuring the moisture content: detecting the content of each water component of the sample by using a low-field nuclear magnetic resonance imager;

the specific water component content measuring steps are as follows:

preheating an instrument: opening an industrial personal computer switch of the low-field nuclear magnetic resonance imager, and preheating the low-field nuclear magnetic resonance imager for 15-40 minutes;

secondly, water film calibration: selecting a proper probe and sequence, and carrying out actual measurement on the sample after correct calibration of a water inlet film;

thirdly, sample detection: selecting a proper sample sequence, placing the sample at a correct position after naming, performing accumulation sampling after confirming detection parameters, and waiting for the end of detection;

fourthly, result query: and after the detection image appears, carrying out inversion and checking a test result.

2. The mango moisture content processing method according to claim 1, wherein the identified sampling width is 0.7 to 1.5cm when determining the mango sampling position, and the determined quarter point is within the identified sampling position.

3. The mango moisture content processing method according to claim 1, wherein the mango is cut as close as possible to the plane of the stone to ensure the need for subsequent sampling.

4. The mango water content processing method according to claim 1, wherein pulp sampling is performed perpendicular to a cut identification part of the pulp slice, a symmetric central axis of the cut part is determined, a sample to be measured is located at the center of the pulp slice, the height of the sample to be measured is the determined sampling width, the sample to be measured is a cuboid with the length of 3-5 cm, the width of 3-5 cm and the height of 0.7-1.5 cm, and the quality of each sample to be measured is guaranteed to be basically consistent in the whole experiment.

5. The mango moisture content processing method according to claim 1, wherein wrapping the sample to be tested is performed by using the edge of a preservative film to avoid touching or pressing the sample to be tested with a hard object.

6. The mango moisture content processing method according to claim 1, wherein a sample to be detected is wrapped, stored in an environment of 4-8 ℃ and detected as soon as possible.

Technical Field

The invention relates to a method for processing and detecting the water component content of fruits, in particular to a method for processing the water component content of mango pulp and detecting the water component content of mango pulp by using a low-field nuclear magnetic resonance imaging technology.

Background

The mango serving as the tropical fruit has attractive color and smooth appearance, and the flesh of the mango is sour, sweet, smooth and rich in nutrition, is known as the king of the tropical fruit and is deeply loved by the general consumers. During the transportation and storage of the mangoes, the water content, especially the free water content, of the fruits gradually decreases with the passage of time, so that the fruits lose water and shrink, and the commodity characteristics of the fruits are influenced. By using a low-field nuclear magnetic resonance imaging technology, the change of the water content of the mangoes in the process is detected, the change rule of the fruit quality can be mastered, the freshness of the mangoes can be more accurately evaluated, and the commodity characteristics and the edible value of the fruits can be measured. Meanwhile, the method has important significance for improving the fresh-keeping means such as fruit packaging, storage and the like.

Disclosure of Invention

The invention aims to provide a mango moisture content processing and detecting method, which can better represent the content of each moisture component in mango pulp and further reflect the quality characteristics and changes of fruits.

The method for detecting the water component content of the mangoes by using the low-field nuclear magnetic resonance imager is realized by the following technical steps:

(1) determining a sampling position: measuring the full length of the mango by using a ruler, determining quartering points of the flesh on two sides, and making sampling marks;

(2) and (3) mango segmentation: respectively cutting off the two sides of mango pulp in parallel with the plane of the mango stone;

(3) sampling pulp: taking the cut pulp, vertically cutting the pulp according to the sampling identification, removing the edges of the pulp at two ends, and adjusting the pulp into a cube to be tested with the length of 3-5 cm, the width of 3-5 cm and the height of 0.7-1.5 cm;

(4) wrapping with a preservative film: preparing a preservative film with the length and the width being 3 times of those of the sample to be tested, carefully wrapping the preservative film, and refrigerating the preservative film to be tested;

(5) and (3) measuring the moisture content: detecting the content of each water component of the sample by using a low-field nuclear magnetic resonance imager;

the specific water component content measuring steps are as follows:

preheating an instrument: opening an industrial personal computer switch of the low-field nuclear magnetic resonance imager to preheat the instrument;

secondly, water film calibration: selecting a proper probe and sequence, and carrying out actual measurement on the sample after correct calibration of a water inlet film;

thirdly, sample detection: selecting a proper sample sequence, naming, putting a sample, confirming detection parameters, performing accumulation sampling, and waiting for the end of detection;

fourthly, result query: after the detection image appears, inversion is carried out, and a test result is checked;

preferably, when determining the mango sampling position, the identified sampling width is 0.7-1.5 cm, and the determined quarter point is within the identified sampling position.

Preferably, the mango is cut as close to the plane of the stone as possible, so that the thickness of the pulp on two sides of the mango is maximized, and the subsequent sampling requirement is ensured.

Preferably, the pulp is sampled by being perpendicular to the cutting identification part of the pulp slice, the symmetrical central axis of the cut part is determined, the sample to be detected is located in the center of the pulp slice, the height of the sample to be detected is the determined sampling width, the sample to be detected is a cuboid with the length of 3-5 cm, the width of 3-5 cm and the height of 0.7-1.5 cm, and the quality of each sample to be detected is guaranteed to be basically consistent in the whole experiment.

Preferably, the parcel will avoid the stereoplasm article to touch when waiting to survey the appearance, perhaps pressing by the fingers of holding of heavier strength, utilizes the plastic wrap edge to wrap up, avoids touching and waits to survey the appearance.

Preferably, the sample to be detected is wrapped and stored in an environment with the temperature of 4-8 ℃ and detected as soon as possible.

Optionally, the wrapped sample to be tested can be carefully taken out before being tested on the machine and placed in a test area to be tested of the instrument, and the damage to the sample to be tested is also avoided in the process.

Preferably, when the low-field nuclear magnetic resonance imager is used for detection, the instrument needs to be preheated for 15-40 min, so that the instrument is ensured to run stably.

Preferably, in the image where the water film calibration occurs, if a peak and a trough are included, the calibration is correct, otherwise, the calibration is continued after the parameters are debugged until the calibration is correct.

Preferably, the sample is placed with care to the location of placement, which may be referenced to the location of the water film when properly calibrated.

Preferably, two samples with the largest expected difference are selected for parameter adjustment before detection, and if the trailing part in the result image is more than one half of the total time, the parameters are indicated to be appropriate, and detection can be performed.

Preferably, the detection and inversion parameters are kept consistent in the whole experiment, the method provides that the accumulation times are more than 2, the sampling mode is selected for inversion, the data volume is more than 50, and the iteration times are more than or equal to 10000, so that more signals can be collected.

Preferably, in the inversion result, the ratio corresponding to each peak area is the content ratio of each moisture component.

Alternatively, the mass of each sample to be measured may be recorded in advance, and the peak area ratio may be divided by the mass for normalization.

The low-field nuclear magnetic resonance imaging technology can effectively detect the content ratio of each water component of mango pulp during storage, can effectively evaluate the quality change and the commodity characteristics of mango, and has the advantages of simple operation, accurate result and strong popularization value.

Drawings

FIG. 1 is a schematic view showing a sampling position of mango pulp on one side of a mango according to the present invention, wherein 1, 2 and 3 are bisectors, 4, 6, 8 and 10 are indicated by discard parts, and 5, 7 and 9 are fruit parts removed according to sampling marks.

Fig. 2 is a schematic diagram of a mango pulp sampling method in the present invention, i.e. sampling of the parts 5, 7, and 9 in fig. 1, where 11 and 13 are two side edge parts of the pulp expressed in the present invention, and 12 is a part to be measured.

FIG. 3 is a graph of the effect of different packages on the loss rate of free water content of mangoes.

Detailed Description

The present invention is described in detail with reference to the following embodiments, which should be understood as being illustrative only and not limiting, and any modifications, equivalents, etc. based on the present invention are within the scope of the present invention.

Example 1

Taking mangoes to be detected, measuring the full length of the mangoes by using a ruler, determining quartering points of the pulps on two sides, and well preparing sampling marks (with the width of 1cm), wherein the quartering points are in sampling positions of the marks; respectively cutting off the two sides of mango pulp in parallel with the plane of the mango stone; taking the cut pulp, vertically cutting the pulp (such as parts 5, 7 and 9 in figure 1) according to the sampling mark, removing the edges of the pulp at two ends, and adjusting the pulp into a cube to be tested (such as 12 in figure 2) with the length of 4cm, the width of 4cm and the height of 1 cm; preparing a preservative film with the length and the width being 3 times of those of the sample to be tested, carefully wrapping the preservative film, and storing the preservative film in an environment with the temperature of 4-8 ℃ for testing; and detecting the content of each water component of the sample by using a low-field nuclear magnetic resonance imager.

During detection, firstly, a switch of an industrial personal computer of the low-field nuclear magnetic resonance imager is turned on, and the instrument is preheated for 30 min; selecting a MesoMR23-060H-I-70mm probe, a Q-FID sequence and a water inlet film, and carrying out actual measurement on the sample after the appearing image comprises a peak and a trough; then selecting a Q-CPMG sample sequence, naming, putting in a sample, setting SW 200KHz, NS 8 and NECH 18000, simultaneously setting P1 to be 19 mus, P2 to be 37 mus, TW to be 5000ms and TE to be 0.45ms, performing accumulation sampling after confirming detection parameters, and waiting for the detection to end; and when the detected image appears, inverting, selecting an SIRT inversion method, selecting data in a sampling mode, wherein the data volume is 200, the iteration number is 100000, and checking a test result. For the same mango, all data measured were recorded and the mean was calculated.

Due to factors such as natural evaporation and damage, the water content of different positions of the same mango is different, the proportion of free water to water in six sampling positions is respectively 88.2%, 89.3%, 91.2%, 89.8%, 90.4% and 91.5% by experiment, the average value is 90.067%, and the standard deviation of the sample is 1.232. The deviation of the experimental result is small, which shows that the moisture content measured by the method can well represent the moisture content of the mangoes, and meanwhile, the method is simple and convenient to operate and short in detection time, and can be used for rapidly measuring the moisture content of the mangoes and evaluating the freshness and quality characteristics of the mangoes.

Example 2

The purchased mangoes were wiped off one by one for surface dirt, trimmed for overlong pedicles and cleaned of juice. The mangoes were randomly divided into 5 groups and unpackaged (blank group, denoted kb), preservative paper packaging (bx), plastic mesh packaging (wt), shock absorbing bubble film packaging (hl), and air bag packaging (qz) were performed, respectively. Randomly placing 5 groups of experimental mangoes on a simulated transportation vibration experiment table, placing in a single layer manner, performing simulated transportation for 24h, performing simulated transportation and storage in a refrigeration house, setting the temperature of the refrigeration house to be 13 ℃, recording as 0 day when vibration is finished, and sampling every 4 days.

Firstly, measuring the total length of mangoes to be measured by using a ruler, determining quartering points of pulps on two sides, and well preparing a sampling mark (the width is 1cm), wherein the quartering points are in the sampling position of the mark; respectively cutting off the two sides of mango pulp in parallel with the plane of the mango stone; taking the cut pulp, vertically cutting the pulp (such as parts 5, 7 and 9 in figure 1) according to the sampling mark, removing the edges of the pulp at two ends, and adjusting the pulp into a cube to be tested (such as 12 in figure 2) with the length of 4cm, the width of 4cm and the height of 1 cm; preparing a preservative film with the length and the width being 3 times of those of the sample to be tested, carefully wrapping the preservative film, and storing the preservative film in an environment with the temperature of 4-8 ℃ for testing; and detecting the content of each water component of the sample by using a low-field nuclear magnetic resonance imager.

During detection, firstly, a switch of an industrial personal computer of the low-field nuclear magnetic resonance imager is turned on, and the instrument is preheated for 30 min; selecting a MesoMR23-060H-I-70mm probe, a Q-FID sequence and a water inlet film, and carrying out actual measurement on the sample after the appearing image comprises a peak and a trough; then selecting a Q-CPMG sample sequence, naming, putting in a sample, setting SW 200KHz, NS 8 and NECH 18000, simultaneously setting P1 to be 19 mus, P2 to be 37 mus, TW to be 5000ms and TE to be 0.45ms, performing accumulation sampling after confirming detection parameters, and waiting for the detection to end; and when the detected image appears, inverting, selecting an SIRT inversion method, selecting data in a sampling mode, wherein the data volume is 200, the iteration number is 100000, and checking a test result. For the same mango, all data measured were recorded and the mean was calculated.

As shown in fig. 3, the largest proportion of the obtained data is the proportion of the free water content, during the storage process, the water content of the mango free water is continuously reduced, the water content loss is continuously increased, and the difference between each experimental group and the blank group is obvious. The water content of the blank group is lost most rapidly in the storage period, the water content is obviously higher than that of other experimental groups after 8 days, and the water content is reduced by 6.76% with that of the air bag group on the 20 th day of storage. The result shows that the air bag can effectively reduce the water loss of the mangoes, the effect of reducing the water loss of other three experimental groups is not as good as that of the air bag group, and the water loss of the blank group is the most. The experimental results show that the moisture content measured by the method can better represent the change of the moisture content of the mangos in the storage process, and help to judge the quality of the protection effect of the mangos by each experimental group. The method has strong practicability and commercial value, and can be used for measuring the water content of the mangos and evaluating the freshness and quality characteristics of the mangos.

Example 3

Measuring the total length of the mango to be measured by using a ruler, determining quartering points of the fruit flesh on two sides, and well preparing a sampling mark (the width is 1cm), wherein the quartering points are in the sampling position of the mark; respectively cutting off the two sides of mango pulp in parallel with the plane of the mango stone; taking the cut pulp, vertically cutting the pulp (such as parts 5, 7 and 9 in figure 1) according to the sampling mark, removing the edges of the pulp at two ends, and adjusting the pulp into a cube to be tested (such as 12 in figure 2) with the length of 4cm, the width of 4cm and the height of 1 cm; preparing a preservative film with the length and the width being 3 times of those of the sample to be tested, carefully wrapping the preservative film, and storing the preservative film in an environment with the temperature of 4-8 ℃ for testing; and detecting the content of each water component of the sample by using a low-field nuclear magnetic resonance imager. In the schematic diagram 1, the mango pulp sections 5, 7 and 9 are designated as sample 1, sample 2 and sample 3, respectively.

During detection, firstly, a switch of an industrial personal computer of the low-field nuclear magnetic resonance imager is turned on, and the instrument is preheated for 30 min; selecting a MesoMR23-060H-I-70mm probe, a Q-FID sequence and a water inlet film, and carrying out actual measurement on the sample after the appearing image comprises a peak and a trough; then selecting a Q-CPMG sample sequence, naming, putting in a sample, setting SW 200KHz, NS 8 and NECH 18000, simultaneously setting P1 to be 19 mus, P2 to be 37 mus, TW to be 5000ms and TE to be 0.45ms, performing accumulation sampling after confirming detection parameters, and waiting for the detection to end; and when the detected image appears, inverting, selecting an SIRT inversion method, selecting data in a sampling mode, wherein the data volume is 200, the iteration number is 100000, and checking a test result.

As shown in table 1, the largest proportion of the mango moisture components measured was free water, which did not easily flow, and the smallest proportion of bound water, with the mean values of 90.63, 7.40, and 1.96, and the standard deviations of 0.31, 0.32, and 0.40, respectively. Experimental data show that the method can quickly and accurately measure the content of each water component in the mango, can be used for representing the change of the content of the water components in the mango and helps to judge the quality of the mango. The method has strong practicability and commercial value, and can be used for measuring the water content of the mangos and evaluating the freshness and quality characteristics of the mangos.

Table 1 mango moisture component content units: is based on

Sample number	Bound water	Not easy to flow water	Free water
				1	2.42	7.12	90.46
2	1.80	7.75	90.45
				3	1.67	7.34	90.99

The above examples are merely illustrative of the methods and steps of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.