CN111616207B - Method for selecting optimal harvesting period of non-respiratory jump type fruit after picking and cold storage - Google Patents

Abstract

The invention discloses a method for selecting the optimal harvest time of non-respiratory jump type fruits after being picked and refrigerated, which comprises the following steps: picking when the non-respiratory jump type fruits grow to the mature period on fruit trees, picking at least in 3 stages, wherein the picking interval time of each stage is 3-4 weeks, storing the fruits in a refrigerator corresponding to the fruit variety after picking, detecting the respiratory intensity of the fruits during the storage period, and selecting the stage with the minimum respiratory intensity to determine the optimum picking stage of the fruits of the variety. Also provides a storage method of the non-respiratory transition type fruit, which comprises the following steps: 1) Selecting the optimal harvesting period of the variety of fruits according to the method; 2) Picking fruits according to the selected optimal picking period, and storing the picked fruits in a refrigerator corresponding to the variety for storage. The fruits harvested according to the harvesting period determined by the method have high fruit quality, low fruit damage rate during storage and best commodity under the same refrigeration condition, the storage tolerance of the fruits is improved by timely harvesting, and the fruits are kept fresh to the greatest extent.

Description

Method for selecting optimal harvesting period of non-respiratory jump type fruit after picking and cold storage

Technical Field

The invention relates to the technical field of agricultural product production, in particular to a method for selecting the optimal harvesting period of non-respiratory transition type fruits after being refrigerated.

Background

The fruits grow to be mature until the fruits can be picked, and the fresh fruits still have respiration after being picked (leaving the tree body) until the fruits are completely mature or reach the optimal eating period. The fruit quality and storage performance are closely related to the harvesting time, so timely harvesting for different varieties is particularly important.

The suitable harvest maturity of fruits is also closely related to its storage and preservation method, and it is disclosed in the literature "harvest maturity of horticultural crop products for preservation" (zhuang xu. Southwest horticulture, 2001,29 (4): 16-17): for citrus fruits used for storage, textbooks show: harvesting is slightly earlier than fresh edible fruits and is harvested when the fruits are nearly ripe; at present, most of fruits for storage are stored when the peel tissues are fully developed, the coloring reaches about 80 percent, and the pulp is not completely softened. Here, only the harvest maturity of the fruits in the conventional storage method is explained, and the requirements of various storage methods on the harvest maturity cannot be reflected. It is believed that "oranges used for storage should be harvested when the peel turns yellow in two thirds of its area" or "fully mature", e.g., wide-skinned oranges should be harvested when the peel turns yellow in 60% of its color, and oranges should be harvested when they are fully colored. The above suggestions are inconsistent and even mutually conflicting, so that the problem of the freshness preservation and harvest maturity is sufficiently found to be worth further exploration. In practical application, shengmmin and the like think that 'fruits are different in storage method and different in harvest maturity, for example, fruits for controlled atmosphere storage are suitable for early harvest, and fruits for cold storage have higher requirements on maturity'; the' one-time research mostly considers that the higher the maturity of the fruits for cold storage is, the better, generally considers that the lower the maturity, the higher the sensitivity of the fruits to low temperature is, the more easily the cold damage occurs.

The maturity of non-respiring fruits is difficult to define, the influence factors are quite many and more complex, and the harvesting periods of the same variety in different producing areas are not completely consistent, so that the harvesting time is mostly in a wide time range by experience and the like. The orange fruits belong to typical non-respiratory transition type fruits, the orange of early and medium maturing varieties is researched more in the past, generally, the color conversion of early and medium maturing peels is positively correlated with the maturity of the fruits, and the maturity can be conveniently judged through the color of the peels and other representations. However, the harvesting period of the late-maturing citrus is not much researched, the harvesting maturity is less understood, and particularly, the specific timely harvesting time is not determined (no uniform basis or specific standard exists). The harvesting period of general fruits such as late-maturing citrus fruits is not only different depending on the variety, age, growing environment, etc., but also related to the purpose and purpose of harvesting. Compared with the tree-leaving storage, tree-hanging storage or instant picking, the majority of fruits are not picked when the tree body is fully ripe, and therefore, the process of after-ripening or turnover storage and transportation is more or less needed.

The maturity of the late-maturing citrus is difficult to judge through appearance characterization and the like, for example, in the aspect of appearance color, the color of fruits of blood oranges in the family of taluoaceae is continuously changed (tends to be purple red) at low temperature, and the color of the peel of the blood oranges is not consistent with that of the pulp of the fruits; the Baoweer navel orange is similar to summer orange, and the green turning phenomenon of the fruit peel exists; the color of the hybrid oranges is not known to be changed in 12 months in the current year, but the hybrid oranges begin to mature in the next three months, so the maturity of the hybrid oranges is difficult to judge according to the color of the peels, and the rough fire peels are not beneficial to measurement by a color difference meter. The harvesting suitability of the fruits is estimated by internal indexes of the fruits or without damage.

Therefore, it is necessary to study the refrigeration specificity of the harvested late-maturing citrus fruits to find out the different storage and transportation harvesting periods.

Disclosure of Invention

The invention aims to solve the problems and provides a method for selecting the optimal harvest time of non-climacteric fruit after being refrigerated.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for selecting the optimal harvest time of non-climacteric fruit after being picked and refrigerated comprises the following steps: picking the fruits after the non-respiratory jump type fruits grow to the mature period on the fruit trees, picking the fruits at least by 3 periods, wherein the picking interval time of each period is 3-4 weeks, storing the fruits in a refrigerator corresponding to the fruit variety after picking, detecting the respiratory intensity of the fruits during the storage period, and determining the period with the minimum respiratory intensity as the optimal picking period of the fruits of the variety.

Preferably, the non-climacteric fruit is late-maturing citrus.

Furthermore, the late-maturing citrus is blood orange or navel orange without knowing fire, the blood orange harvesting period is 12 months from the current year to 3 months from the next year after flowering, the unknown fire harvesting period is 2-5 months from the second year after flowering, the navel orange harvesting period is 3-5 months from the next year after flowering, the fruits are harvested in at least 3 stages within the time range of each harvesting period, the time interval of each stage of harvesting is 3-4 weeks, the harvested fruits are stored in a refrigerator corresponding to the fruit variety, the respiratory intensity of the fruits is detected during the storage period, and the stage with the minimum respiratory intensity is selected to be determined as the optimal harvesting period of the fruit variety.

In the technical scheme, the respiration intensity is detected after the picked fruits are pre-cooled and pre-stored before being put in a warehouse or are at least 1-2 weeks after entering the refrigerator, the respiration intensity of the picked fruits at different periods is detected, and the period with the minimum respiration intensity is selected to be determined as the optimal picking period of the variety of fruits.

The invention also provides a storage method of the non-respiratory transition type fruits, which comprises the following steps:

1) Selecting the optimal harvesting period of the fruits: selecting the optimal harvesting period of the variety of fruits according to the method;

2) And picking the fruits of the variety according to the selected optimal picking period, and storing the picked fruits in a refrigerator corresponding to the variety for storage.

The invention has the beneficial effects that: the method overcomes the technical prejudice that the higher the harvest maturity of the fruits for refrigeration is better in the prior art, and provides a novel selection method for the optimal harvest time of the fruits after the non-respiratory jump type fruits are harvested and refrigerated, the fruits harvested in the harvest time determined by the method have high fruit quality, low storage disease rate and the best commodity under the same refrigeration condition, and the timely harvest not only improves the storage resistance of the fruits, but also enables the fruits to be preserved to the maximum extent.

Drawings

Fig. 1 is the blood orange storage lesion results at different harvest stages.

Fig. 2 is a graph of respiration intensity results in storage of blood orange fruits at different harvest stages.

FIG. 3 is the results of the storage lesions after third-phase fire unknown.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to be limiting.

The experimental procedures in the following examples are conventional unless otherwise specified.

Example 1

1 materials and methods

1.1 fruit materials and apparatus

The blood orange of Taruo family is collected from orchard of resource room of Citrus research institute of Chinese academy of agricultural sciences (tree age for more than 5 years); fire is not known to be collected in orchards (tree age < 3 years) of the storage subjects of the orange research institute of Chinese academy of agricultural sciences; baoweer navel oranges are produced from orchards in the festival of Chongqing and full bearing age. The time interval of the harvesting period is about one month (the second period and the third period of the Bawell navel oranges are not known to be fire and are separated by about three weeks); all the plants are picked in three stages, and the specific mining time is shown in table 1. 3-5 boxes are adopted for each variety of fruits at each stage, and each box contains about 80 fruits (the number of the fruits is different according to the variety).

The number of the cold storages with adjustable humidity is multiple; a plurality of plastic fruit boxes and single fruit packaging bags are arranged; and a color difference meter and a refractometer are necessary for detection, and the like.

1.2 protocol and sampling test

The procedure from picking to warehousing of the fruits was standardized according to the corresponding standards (orange storage NY/T1189-2006), with the experimental protocol see table 1.

TABLE 1 test table for each harvest period of blood orange, unknown fire and navel orange

At least three repetitions per treatment number, each repetition being a box of fruit; and (3) monitoring and regularly investigating fruit storage lesions in real time, removing rotten fruits, and finally counting the morbidity such as rotting rate of each treatment and index data such as internal quality (GB/T12947-2008 fresh citrus).

1.3

1.3.1 investigation of storage lesions in fruits

The disease fruit rate described herein is the visual infectivity during storage plus the percentage of physiologically occurring fruit to the total number of fruits before storage; similarly, the rot rate and the brown spot rate are respectively the rot rate (%) = (number of rotten and mildewed fruits/total number of fruits) × 100; speckle rate (%) = (number of speckle dry fruits/total number of fruits) × 100.

1.3.2 determination of breath intensity

Breath detection using alkali to absorb CO ₂ The method still has three repetitions of the same treatment per detection, and each repeated sampling fruit number is about 10 according to the fruit size. Detection time of respiration intensity: each sample is tested at least once a month, because fresh fruits which just enter the refrigeration house are high in respiration, oneThe detection is carried out after the stability is achieved (1-2 weeks).

1.3.3 determination of quality Iso-intrinsic index

Fruit quality analysis, wherein the number of each repeatedly sampled fruit is at least 10, three repeated detection after storage is carried out, indexes such as soluble solid matters, sugar, acid, vitamin C and the like are detected according to national standards (fresh orange fruit inspection method GB/T8210-2011) and Chinese patent ZL 2013102539.8 (patent name: a reducing sugar direct titration method for improving titration accuracy), and quality indexes TSS, RS, TA and VC respectively represent the soluble solid matters, the reducing sugar, total acid (titratable acid) and the vitamin C; herein, the solid acid ratio (TSS: TA) and the sugar acid ratio (RS: TA) are calculated by dividing the mean value, namely TSS/TA and RS/TA respectively.

L in the color difference is a brightness value, a ^* Red-green color difference, b ^* -yellow-blue color difference, OJ is the instrument's composite score for juice; a is ^* Greater positive values of (b) greater red, and greater red ^* The more positive the value of (b), the darker the yellow color, the hue angle of ho, and the more violet red the value of ho is within 90 deg.. The change before and after storage, i.e., the difference between the respective index values (after storage-before storage), is represented by the symbol Δ.

1.4 statistics of data

The data in the test result chart are expressed as the mean ± relative standard deviation of three replicates of each treatment number, except for the individual correspondences; the data were analyzed and plotted using Microsoft Excel, and the significance of differences was analyzed using SPSS software.

2 results and analysis

2.1 blood orange of Taurolaceae

The blood oranges collected in the three periods are collected and stored in the same storehouse (6-8 ℃/RH 80%), and all the fruits collected in the three periods are transferred to the indoor (20-22 ℃) shelf life half month after the storage of the blood oranges collected in the latest one period reaches three months. The storage pathological changes of the blood oranges (hereinafter referred to as blood oranges) in the family of taluoke and the shelf survey statistics are shown in fig. 1, the monthly average diseases of different harvesting periods are counted from the pathological change survey data, and it can be seen that the blood oranges in the first period are better, the diseases such as rottenness are shown to be the lowest, and the disease rate in the shelf period is also obviously lower than that in the III period of T3 blood oranges.

The results of the fruit quality measurements are shown in table 2 below.

TABLE 2 quality test data of blood orange after storage

Note: a, b, c- -identification of significance of difference (p < 0.05)

The reducing sugar content of the blood orange in the first stage and the second stage is respectively increased by 1.49 percent and 0.59 percent compared with that of the blood orange in the harvesting process, while the reducing sugar content in the blood orange in the third stage is reduced by 1.29 percent; the vitamin C content in the first, second and third stages is respectively reduced by 6.99%, 16.05% and 8.61% when the fruits are harvested, which shows that the quality of the fruits in the first stage is relatively well maintained, and the detection of the fruit sample after the longest time (5 months) shows that the acid fixation ratio, the sugar-acid ratio and the juice yield of the first stage are all the highest, the vitamin C is remarkably the highest (see table 2), which shows that the quality of the fruits harvested in the first stage is well maintained.

The results of the breath test data are shown in fig. 2, from which it can be seen that the breath intensity of the first stage harvest is lower and significantly lower than the second stage harvest. This should also be evidence of a stored morbidity outcome, i.e. lower incidence of respiration in stage I fruit and vice versa.

The color difference detection of the juice at the end of the storage of the blood orange (5 months and 20 days) and the comparison with the color difference index at the time of collection can reflect the color change of the inner quality of the fruit at different collection periods (see table 3).

TABLE 3 color difference index of blood orange juice and its change before and after storage

The data in Table 3 reflect that the juice color at stage I of the blood orange is not only highest at a-value and OJ and lowest at hue angle ho, but also most red-turning (the increase of Delta a is the most), and tends to be purplish red (the increase of Delta ho is obviously smaller), and the comprehensive score OJ is also obviously improved.

Therefore, the blood oranges picked in the first period have the least storage morbidity; the breathing intensity is also lowest; the quality and color difference of the stored fruits reflect that the fruits are better in the stage I. Meanwhile, the deepening of the color of the fruit juice can also help the synthesis and transformation of substances such as anthocyanin and the like of the fruit due to low temperature.

2.2 the unknown fire of hybrid oranges

It is not known that fruits are picked in 2-4 months of the next year after picking with fire, namely, picked in three time periods of 2 months 6 days, 3 months 6 days and 3 months 27 days, and then stored in the same storehouse (4-6 ℃/RH 70%), and the fruits picked in the latest period are counted after being stored for at least 3 months (stored to 7 months and 7 days), and the data results are shown in FIG. 3.

Although the parallelism of brown spot and rot fruits treated three replicates each in the warehouse survey was not good (the difference was not significant), statistics of their final disease data could lead to: the total morbidity and the monthly average morbidity of the S1 are the highest, and in comparison, the last stage S3 is better.

Finally (7 months and 14 days), the respiration intensity (mgCO) of S1, S2 and S3 was measured ₂ /(kg · h)) 14.80 ± 1.53, 12.43 ± 1.20, 10.45 ± 0.57, respectively, with S1 being the most prominent, which also demonstrates the storage lesion outcome.

The data on the endoplasmic reticulum test after the staged harvest and storage are shown in Table 4. In comparison, the color difference index is the worst in the first stage of S1, the values of a, b and OJ are all obviously the lowest, and the value of S3 is slightly better than that of S2. For quality analysis, except that the solid content of S1 is lower and the reducing sugar is lower than the index data during collection, the solid content and the reducing sugar of S3 and S2 are both improved compared with the solid content and the reducing sugar during collection; and the indexes of solid matters, sugar and the like after the S3 harvest and storage are high, and the obvious difference from the S2 can be caused by the short time interval between the two harvest periods.

TABLE 4 unknown data of relevant indexes of juice testing at the end of storage of fire staged harvested fruits

Therefore, from the viewpoint of storage investigation, quality, color difference, etc., the S3 number picked at the latest stage is the best, and the respiration intensity of the S3 number is also the smallest.

2.3 Baoweer navel orange

After three harvesting periods P1, P2 and P3, the pathological changes of the plants are investigated, and the pathological changes of the plants after about 100 days are shown in Table 5, which lists the specific data of three repetitions of each harvesting period.

TABLE 5 Boweier navel orange lesion conditions and breath detection data results in different harvesting periods

The data show that the rot rate is higher in stage I, the brown spot rate is higher in stage III, and the total incidence is less in stage II P2; the disease fruit rate (%) of P1, P2 and P3 in three stages is 1.04 + -1.07, 0.43 + -0.74 and 1.44 + -1.60 respectively.

The respiration intensity of the picked fruits in the three periods changes along with the time and has basically consistent trend, namely the fruits are higher at the beginning of picking (higher at the early stage) and tend to be stable in the later period, and the respiration intensity of the fruits in each period is influenced by the storage temperature in the warehouse. In the third phase, the respiratory intensity of P2 in the second phase is lowest, while P1 in the first phase is always highest, and the respiratory intensity of P1 after three months (6 months and 11 days) is 15.23 +/-1.04/mg CO ₂ /(kg · h), the breath intensity measurements up to the end (7 months and 31 days) are as listed in table 5, with P1 still being the highest significant.

TABLE 6 quality related indexes before and after storage of Bowell navel orange in third stage

The fruits harvested in three periods and the quality results after storage are detailed in a table 6, and although indexes of No. P3 in the period III are all high, the fruits are mainly caused by late harvesting and shortest storage period except for the influence of sampling factors, and even if the fruits are not obviously different from sugar, acid and Vc in the P2 in the period II; however, the quality index of the phase I P1 is reduced most, and the total acid of the phase I P1 is reduced by 61.8 percent and 37.85 percent compared with the total acid of the phase I P when the phase I is collected. The fruits harvested in different periods have the same fruit storage effect, the fruit juice brightness L value is reduced, but the a, b and OJ values are all increased, the change range is shown in the table 7, and therefore, the brightness reduction (delta L) of the P2 is the least (1.185), the rising ranges of delta a, delta b and delta OJ reflecting red, yellow and the comprehensive values are the highest, the P2 in the II period is the best, and the respiratory intensity of the P2 is the lowest. It has also been found in practice that the fruit skin has "turned green" at stage III.

TABLE 7 color difference index change values of juice before and after storage of Bawell navel orange in three stages

In conclusion, the better harvesting periods of the red oranges are the first period (collecting on 17 days in 12 months in the current year), the third period (collecting on 27 days in 3 months in the next year) and the second period (collecting on 9 days in 4 months in the next year) of the powell navel oranges in taluoke.

The refrigeration effect of the research is based on data results of indexes such as quality detection, respiration intensity, storage pathological changes and the like before and after the refrigeration of fruits, and meanwhile, the postharvest pathological changes and the respiration intensity of the fruits are reflected to have great correlation, namely, the larger the respiration intensity of the same variety under the same environmental condition, the higher the incidence rate is, the faster the quality is reduced. Although the harvesting periods of the late-maturing oranges are different due to varieties, the late-maturing oranges have similar postharvest reactions, the method can determine the optimal harvesting periods of different late-maturing oranges, and timely harvesting not only improves the storage resistance of the fruits, but also enables the fruits to be preserved to the maximum extent. The proper harvesting period of other non-respiratory transition type fruits can be analyzed and judged by the idea.

Claims (2)

1. A method for selecting the optimal harvest time of non-respiratory jump type fruits after being picked and refrigerated is characterized by comprising the following steps: picking the fruits at least in 3 stages after the non-climacteric fruits grow to the mature period on the fruit trees, wherein the picking interval time of each stage is 3-4 weeks, storing the fruits in a refrigerator corresponding to the fruit variety after picking, detecting the respiratory intensity of the fruits during the storage period, detecting the respiratory intensity of the picked fruits at least 1-2 weeks after the picked fruits enter the refrigerator, detecting the respiratory intensity of the picked fruits at different periods, detecting the respiratory intensity once at least every month, and selecting the stage with the minimum respiratory intensity to determine the optimum picking stage of the fruits;

the non-respiratory jump type fruits are late-maturing citrus, talocos, or burning-unaware or powell navel oranges, the harvesting period of the talocos is 12 months to 3 months in the next year after flowering, the harvesting period of the burning-unaware is 2 to 5 months in the next year after flowering, and the harvesting period of the powell navel oranges is 3 to 5 months in the next year after flowering.

2. A method for storing non-climacteric fruit, which is characterized by comprising the following steps:

1) Selecting the optimal harvesting period of the fruits: selecting the optimal harvest time of the variety of fruit according to the method of claim 1;

2) And picking the fruits of the variety according to the selected optimal picking period, and storing the picked fruits in a refrigerator corresponding to the variety for storage.

Images