CN110658311A - Device and method for measuring fruit respiration rate - Google Patents

Abstract

A device and a measuring method for measuring the respiration rate of fruits belong to the technical field of measuring the respiration rate of fruits. The device includes a closed CO ₂ assimilation chamber and a photosynthesis measuring instrument. The photosynthesis measuring instrument is provided with two CO ₂ detectors. One end of the inlet pipeline and the gas outlet pipeline are respectively connected to the CO ₂ detector, and the other end is connected to the CO 2 detector. CO ₂ assimilation chamber, through the intake pipeline to introduce CO ₂ , when measuring, the fruit is placed in a closed CO ₂ assimilation chamber, the change of CO ₂ in the CO ₂ assimilation chamber is the difference generated by the fruit respiration. The invention is in a sealed state during measurement, and the measured data is accurate. In the present invention, a bracket is arranged below the assimilation chamber, so that the assimilation chamber can be separated from the test bench, the gas inlet and outlet pipelines are connected at the bottom of the assimilation chamber, and the gas is introduced from the lower part to provide a fan for uniform mixing. By adopting the method of the invention, the respiration rate of the fruit can be measured quickly and accurately, and the basis for setting the postharvest storage conditions and further research of the fruit can be provided.

Description

A kind of device and measuring method for measuring fruit respiration rate

technical field

The invention belongs to the technical field of fruit respiration rate measurement, in particular to a device and a measurement method for measuring fruit respiration rate.

Background technique

In the process of growing and maturing, fruit and vegetable crops should be picked and stored in time according to their maturity. According to the storage environment and storage time, the maturity will change. When the fruit respiration is the highest and the ethylene release is the largest. , the maturity is the best, and the taste and quality of the fruit are the best; how to measure the respiration rate and ethylene release is very important to judge the maturity of the fruit, which is of great significance for the study of postharvest fruit storage.

In addition, causal vegetable crops have the characteristics of high water content, easy damage, many types, and easy to rot and deteriorate. Usually after picking, they will be affected by physiological phenomena such as respiration, transpiration, ethylene ripening, and dormancy, and they will be affected by their own during the storage process. Due to the influence of respiration and storage environment, the water in the fruits and vegetables will gradually lose, causing the fruits and vegetables to wilt, and prone to quality problems such as water loss, weight loss, rapid softening, fruit rot, and browning of the pulp. Therefore, how to monitor the respiration rate of fruits and vegetables in the cold chain logistics environment is an important issue.

The existing measurement methods usually use two methods of alkali titration or oxygen electrode. The alkaline titration method is to use quantitative lye to absorb the amount of CO2 released by the fruit within a certain period of time, and then titrate the remaining alkali with _acid , then the amount of _CO2 released by respiration can be calculated, and its respiration intensity can be obtained. This method has complicated operation steps and takes a long time to measure a sample. It is difficult to ensure the consistency of the results between different replicates of the same sample, and at the same time, the multi-step acid-base titration reaction will also cause large errors in the results. The oxygen electrode method is a method in which the oxygen electrode is used to cut part of the pulp of the fruit and use the oxygen electrode to measure the difference in the redox potential of the positive and negative electrodes caused by the dissolved oxygen in the solution after the respiration of the isolated pulp. The respiration intensity is irreversible to the fruit, and it does not reflect the respiration intensity of the intact fruit. Therefore, it is very necessary to invent a method for measuring fruit respiration rate which is easy to operate and does not damage the fruit, and provides necessary prerequisites for the research on postharvest storage conditions and storage quality of fruits.

SUMMARY OF THE INVENTION

In view of the above-mentioned technical problems, the present invention provides a device and a measuring method for measuring the respiration rate of fruit, the measuring device can measure the respiration rate of the whole fruit, the measuring method is simple, the fruit is not damaged, and the measured fruit is still usable For the determination of other parameters, it saves difficult-to-obtain experimental materials.

The purpose of this invention is to realize through the following technical solutions:

The present invention is a device for measuring the respiration rate of fruits, which includes a closed _CO2 assimilation chamber and a photosynthesis measuring instrument. The photosynthesis measuring instrument is provided with two _CO2 detectors, one end of an air inlet pipeline and an air outlet pipeline. Connect the CO ₂ detectors respectively, the other end is connected to the CO ₂ assimilation chamber, and the CO ₂ is introduced through the intake pipeline. When measuring, the fruit is placed in a closed CO ₂ assimilation chamber, and the change of CO ₂ in the CO ₂ assimilation chamber is the fruit respiration The difference produced by the action.

Preferably, the CO ₂ assimilation chamber is provided with a base for placing the fruit, the base is provided with air inlet holes and air outlet holes, and a fan is arranged under the base to mix the gas in the CO ₂ assimilation chamber uniformly.

Preferably, the air inlet of the air inlet pipeline and the air outlet of the air outlet pipeline are located on both sides of the base at the bottom of the CO ₂ assimilation chamber.

Preferably, the volume of the CO ₂ assimilation chamber is 1.5-2 times the volume of the fruit to be tested.

Preferably, the area of the bottom plate of the CO ₂ assimilation chamber is 1.5-2 times the maximum cross-section of the fruit to be tested.

Preferably, an end cover is provided on the top of the CO ₂ assimilation chamber, and a sealing ring is provided on the outer periphery of the end cover, and the sealing ring is matched and sealed with the chamber wall of the CO ₂ assimilation chamber.

Preferably, an end cap is arranged on the top of the CO ₂ assimilation chamber, a strap buckle is arranged on the outer periphery of the end cap, and a strap buckle is installed on the outer wall of the CO ₂ assimilation chamber. Lace-up buckle on the airtight connection.

Preferably, a temperature sensor is also provided in the CO ₂ assimilation chamber.

Preferably, a support frame is also provided at the bottom of the CO ₂ assimilation chamber.

The measuring method of the device for measuring the fruit respiration rate of the present invention comprises the following steps:

(1) Set the volume and bottom area parameters of the CO ₂ assimilation chamber on the photosynthesis measuring instrument, and the set temperature is the ambient temperature of fruit tree storage;

(2) The starting point of the respiration rate measurement is set as the CO ₂ change in the CO ₂ assimilation chamber is 300ppm, and the maximum change time is 60s;

(3) First idling and mixing the air to achieve the same internal and external environment;

(4) Place the fruit in the CO ₂ assimilation chamber, turn on the photosynthesis meter to measure, meet any one of the conditions in step (2), and record the data.

(5) According to the difference of CO ₂ detected by the CO ₂ detector connected to the intake pipeline and the CO ₂ detector connected to the gas outlet pipeline per unit time measured by the photosynthesis analyzer, as well as the fresh weight and weight of the fruit weighed Take the cross section of the _CO2 assimilation chamber and determine the respiration rate of the fruit as:

Respiration rate = _dCO2 x S/W.

The beneficial effects of the present invention are:

1. The measuring device of the present invention is in a sealed state during measurement, and the measured data is accurate.

2. In the present invention, a fan is arranged under the base where the fruit is placed in the assimilation chamber to accelerate the flow of the gas in the assimilation chamber, so that the gas is uniform and the measured data is more accurate. A bracket is arranged below the assimilation chamber, which can make the assimilation chamber leave the test bench, and it is convenient for the inlet and outlet pipelines to be connected to the bottom of the assimilation chamber, and the gas is introduced from the lower part to provide a fan to mix evenly.

3. Using the measuring method of the present invention, the respiration rate of the fruit can be measured quickly and accurately, and the basis for setting the storage conditions of the fruit and further research can be provided.

4. The method for measuring the respiration intensity of the present invention is not destructive to the fruit, can reflect the respiration intensity of a complete fruit, can be monitored during postharvest storage, and is more reliable.

5. The fruit whose respiration intensity is measured in the present invention can still be used for the determination of other parameters, saving experimental materials that are difficult to obtain.

6. The measuring device of the present invention can be used for the research of the respiration intensity at different storage temperatures after harvesting.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention.

FIG. 2 is a schematic structural diagram of the base in Embodiment 1. FIG.

FIG. 3 is a schematic structural diagram of the base in Embodiment 2. FIG.

In the picture: 1. Photosynthesis tester, 2. Inlet pipeline, 3. Outlet pipeline, 4. Support frame, 5. Fan, 6. Base, 7. CO ₂ assimilation chamber, 8. Strap, 9. Tie Buckle, 10. Air vent, 11. End cap.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Embodiment 1: As shown in FIG. 1, a device for measuring the respiration rate of fruits of the present invention includes a closed _CO2 assimilation chamber 7 and a photosynthesis measuring instrument 1, and the photosynthesis measuring instrument 1 is provided with two CO ₂ detector, one end of the inlet pipeline 2 and the gas outlet pipeline 3 are respectively connected with a CO ₂ detector, the other end is connected to the CO ₂ assimilation chamber 7, and CO ₂ is introduced through the inlet pipeline 2. During measurement, the fruit is placed in a closed In the CO ₂ assimilation chamber 7, the change of CO2 in the CO ₂ assimilation chamber 7 is the difference produced by the fruit respiration.

The photosynthesis measuring instrument used in this example is the PPsystems TPS-2 portable photosynthesis measuring system. Other types of photosynthesis assay systems may also be used.

As shown in FIG. 2 , the _CO2 assimilation chamber 7 is provided with a base 6 for placing fruits, and three arc-shaped ventilation holes 10 are opened on the base 6. In this example, as shown in FIG. 2, the opened ventilation holes 10 are along the The arc-shaped strip holes arranged at equal intervals around the circumference are provided with a fan 5 under the base 6, and the gas in the CO ₂ assimilation chamber 7 is uniformly mixed by the fan 5.

The air inlet of the air inlet pipeline 2 and the air outlet of the air outlet pipeline 3 are placed on both sides of the base 6 at the bottom of the CO ₂ assimilation chamber.

The volume of the CO ₂ assimilation chamber 7 is 1.5 times the volume of the fruit to be tested. The area of the bottom plate of the CO ₂ assimilation chamber 7 is 1.5 times the maximum cross section of the fruit to be tested.

The top of the CO ₂ assimilation chamber 7 is provided with an end cover 11 , and a sealing ring is provided on the outer periphery of the end cover 11 , and the sealing ring is matched and sealed with the chamber wall of the CO ₂ assimilation chamber 7 .

The top of the _CO2 assimilation chamber 7 is provided with an end cap 11, a strap buckle 9 is arranged on the outer periphery of the end cap 11, and a strap 8 is set on the outer circumference of the _CO2 assimilation chamber 7 chamber wall corresponding to the strap buckle 9, and is connected to the end through the strap 8. The strap buckle 9 on the cover 11 is tightly connected. In this example, the CO ₂ assimilation chamber 7 and its base are all made of transparent materials, such as resin, plastic or glass materials.

The _CO2 assimilation chamber 7 is also provided with a temperature sensor for measuring the temperature in the _CO2 assimilation chamber 7, and the temperature is displayed on the inner wall of the assimilation chamber, while ensuring that the fruit is not touched.

The bottom of the CO ₂ assimilation chamber 7 is also provided with a support frame 4 , which is convenient for placing the CO ₂ assimilation chamber 7 and for ventilation measurement.

The measuring method of the device for measuring the fruit respiration rate described in this example includes the following steps:

(1) on photosynthesis measuring instrument 1, set CO _The volume and bottom area parameter of assimilation chamber 7 are identical with the actual volume and bottom area of _CO assimilation chamber 7, and setting temperature is the ambient temperature that fruit tree is stored;

(2) Set the change amount of CO ₂ in the CO ₂ assimilation chamber 7 to 300ppm, and the maximum change time of CO ₂ is t=60s;

(3) First idling and mixing the air to achieve the same internal and external environment;

(4) Place the fruit in the CO ₂ assimilation chamber 7, turn on the photosynthesis measuring instrument 1 to measure, meet any of the conditions in step (2), and record the data.

According to the difference of CO ₂ detected by the CO ₂ detector 12 connected to the inlet pipe 2 and the CO ₂ detector 12 connected to the outlet pipe 3 per unit time of the photosynthesis instrument 1 (dCO ₂ /μmol s ^-1 m ^{- 2} ), and the fresh weight of the fruit (FW/g) and the cross section (S/m ² ) of the CO ₂ assimilation chamber measured to determine the respiration rate of the fruit, and the specific calculation method is as follows:

Respiration rate (μmol s ^-1 g ^-1 FW) = dCO ₂ ×S/W

The parameter data of different fruits measured by the device and method of this example are as follows:

Table 1 Comparison of fruit respiration rates of three different respiration variants

As shown in Table 1, the respiration rate values of three kinds of fruits measured by this method show that the respiration intensity of apple is higher than that of Nanguo pear, and the repeatability is better. It can be seen that the device for measuring the respiration rate of fruit described in this example and The measurement method can be applied to the determination of the respiration rate of other fruits.

The parameter data of different fruits measured by the device and method of this example and other different methods are as follows:

Table 2 Effects of different methods on the determination of apple fruit respiration rate

As shown in Table 2, by comparing the three methods for measuring respiration rate, it is found that the consistency of the results between different repetitions of the alkaline titration method is poor, which may be caused by the errors caused by the cumbersome operation steps of this method; The value of the measured respiration rate is small, which may be due to the irreversible damage to the fruit by this method, which destroys part of the fruit's respiratory system, and does not reflect the respiration intensity of the intact fruit. The respiration rate of apple fruit measured by the method is stable and repeatable, while maintaining the integrity of the fruit, and can still be used for the determination of other parameters.

This example is used to measure the postharvest respiration rate of apple fruit under different storage temperature conditions. The parameter data of different fruits measured by the device and method of this example are as follows:

Table 3 Effects of different storage temperatures on apple fruit respiration rate

As shown in Table 3, the respiration rate of apple fruit at different temperatures measured by this method, the research shows that the respiration rate intensity of apple is 25℃>15℃>5℃. It can be seen that low temperature can effectively inhibit the respiration rate of apple fruit.

This example is used to determine the respiration rate of apple fruits at different periods after harvest and the effect of exogenous spraying of different concentrations of CaCl ₂ on the respiration rate of apples. The parameter data of different fruits measured by the device and method of this example are as follows:

Table 4 Effects of different concentrations of CaCl ₂ on the respiration rate of apple fruits at different times after harvest

It can be seen from the above table 4 that the apple respiration rate values measured by different storage methods in different periods, the research shows that exogenous spraying of CaCl ₂ can prolong the storage time of apples, and the effect of 2% CaCl ₂ is better, and the effect is better in 5 days and 10 days are the most obvious. The device and the measuring method for measuring the respiration rate of the fruit described in this example are accurate and fast, which provides a basis for scientific research.

Example 2: The difference between this example and Example 1 is that the volume of the CO ₂ assimilation chamber described in this example is 1.7 times the volume of the fruit to be tested. The floor area of the CO ₂ assimilation chamber is 1.6 times the maximum cross-section of the fruit to be tested. As shown in FIG. 3 , in this example, a plurality of circular ventilation holes 10 are opened on the base 6 , and other shapes of ventilation holes are also possible. The measurement method and measurement accuracy are the same as in Example 1.

Example 3: The difference between this example and Example 1 is that the volume of the CO ₂ assimilation chamber described in this example is twice the volume of the fruit to be tested. The area of the bottom plate of the CO ₂ assimilation chamber is 1.8 times the maximum cross section of the fruit to be tested. The measurement method and measurement accuracy are the same as in Example 1.

Example 4: The difference between this example and Example 1 is that the volume of the CO ₂ assimilation chamber described in this example is twice the volume of the fruit to be tested. The area of the bottom plate of the CO ₂ assimilation chamber is 2 times the maximum cross section of the fruit to be tested. The measurement method and measurement accuracy are the same as in Example 1.

It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or It is equivalent to replacement to achieve the same technical effect; as long as the needs of use are met, they are all within the protection scope of the present invention.

Claims (10)

1. A device for measuring the respiration rate of fruit, characterized by: comprising a closed CO₂Assimilation chamber and photosynthesis apparatus, wherein the photosynthesis apparatus is provided with two CO₂One end of the detector, one end of the air inlet pipeline and one end of the air outlet pipeline are respectively connected with CO₂A detector with the other end connected with CO₂Assimilation chamber, introducing CO via air inlet pipeline₂When measuring, the fruit is placed in sealed CO₂Assimilation of indoor CO₂Assimilation of indoor CO₂The variation is the difference generated by the respiration of the fruit.

2. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the CO is₂Assimilation indoor is equipped with the base of placing the fruit, and it has inlet port and venthole to open on the base, sets up the fan below the base, through fan mixing CO₂Assimilating the gas in the chamber.

3. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the air inlet of the air inlet pipeline and the air outlet of the air outlet pipeline are respectively arranged in the CO₂Two sides of the base at the bottom of the assimilation chamber.

4. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the CO is₂The volume of the assimilation chamber is 1.5-2 times of the fruit volume to be measured.

5. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the CO is₂The area of the bottom plate of the assimilation chamber is 1.5-2 times of the maximum cross section of the fruit to be measured.

6. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the CO is₂The top of the assimilation chamber is provided with an end cover, the periphery of the end cover is provided with a sealing ring, and the end cover is connected with CO through the sealing ring₂The wall of the assimilation chamber is matched and sealed.

7. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the CO is₂The top of the assimilation chamber is provided with an end cover, the periphery of the end cover is provided with a binding belt buckle, and CO is arranged₂The assimilation outdoor wall installs the bandage buckle, even has the bandage on the bandage buckle, connects the bandage buckle airtight connection on the end cover through the bandage.

8. According to the claimsClaim 1 the device for measuring fruit respiration rate is characterized in that: the CO is₂And a temperature sensor is also arranged in the assimilation chamber.

9. Device for measuring the fruit respiration rate according to claim 1, characterized in that: the CO is₂The bottom of the assimilation chamber is also provided with a support frame.

10. Measurement method using a device for measuring the fruit respiration rate according to claim 1, characterized in that: the method comprises the following steps:

(1) setting CO on photosynthesis measuring instrument₂The volume and bottom area parameters of the assimilation chamber are set as the environmental temperature for storing the fruit trees;

(2) setting the starting point of respiration Rate measurement to CO₂Assimilation of indoor CO₂The variation is 300ppm, and the maximum variation time is 60 s;

(3) firstly, idling and uniformly mixing air to achieve the consistency of internal and external environments;

(4) in CO₂Placing fruits in an assimilation room, starting a photosynthesis determinator for measurement, meeting any condition in the step (2), and recording data;

(5) according to CO connected with the air inlet pipeline in unit time measured by the photosynthetic apparatus₂CO connected with detector and gas outlet pipeline₂CO detected by the detector₂And the fresh weight of the fruit and the measured CO₂Assimilating the cross section of the chamber, determining the respiration rate of the fruit as:

breath rate dCO₂×S/W。

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