A method for inducing red mango coloring using UV-A / white light

Abstract

The present invention provides a method for inducing red mango coloring by using UV-A / white light, wherein the UV-A light intensity is selected from 101.3 to 123.8 μW·cm ‑2 、198.3~242.3μW·cm ‑2 and 316.2~386.5μW·cm ‑2 , white light intensity 9000~11000Lux. The present invention aims at harvesting uncolored red mangoes at the green and ripe stage, adding three different light intensity gradients of low, medium and high UV-A to white light for induction treatment, and the temperature, humidity and light in the induction environment are all controllable. Continuous treatment for a period of time can effectively induce the accumulation of anthocyanins, promote coloring, and improve the appearance quality, nutritional quality and commercial quality of mangoes. The method of the present invention is reasonably designed, simple to operate, safe and effective, has low requirements on equipment, can be operated on a large scale, and can be demonstrated and promoted for commercial production.

Description

Technical Field

[0001] The invention relates to the technical field of post-harvest fruit coloring, and in particular to a method for inducing red mango coloring by using UV-A / white light. Background Art

[0002] Mango (Mangifera indica L.) belongs to the genus Mangifera in the family Anacardiaceae. It is known as the "king of tropical fruits" for its rich nutrition and unique flavor. The color of mango is one of the most intuitive and important factors for consumers to judge the quality of the fruit, and it determines the commodity value of the fruit to a large extent.

[0003] UV occupies a wide band in the non-ionizing region of the electromagnetic spectrum between the wavelength range of X-rays (200nm) and visible light (400nm), with a wavelength of 100 to 400nm, which can be subdivided into long wave (ultraviolet radiation A, UVA, 315 to 400nm), medium wave (ultraviolet radiation B, UVB, 280 to 315nm) and short wave (ultravioletradiation c, UVC, 200 to 280nm). UV has been reported to be related to the color of fruits and vegetables, but different types of fruits and vegetables may respond differently to UV light. Perkins-Veazie et al. found that the anthocyanin content of "Bluecrop" blueberries increased by 10% when treated with UVC, while the anthocyanin content of "Collins" blueberries was not affected.

[0004] In addition, in addition to light, changes in pigment content are also affected by many factors such as temperature, ultraviolet intensity, and humidity. Summary of the invention

[0005] In view of the above technical problems, the present invention aims to provide a method for inducing red mango coloring by UV-A / white light, which adds UV-A treatment with different light intensity gradients to white light, thereby solving the problem of decreased appearance quality caused by uneven coloring in mango production, thereby better meeting consumer needs.

[0006] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0007] A method for inducing red mango coloring using UV-A / white light, wherein the UV-A light intensity is selected from 101.3 to 123.8 μW·cm -2 、198.3~242.3μW·cm -2 and 316.2~386.5μW·cm -2 , white light intensity 9000~11000Lux.

[0008] Preferably, the environmental conditions for inducing red mango coloring also include: a temperature of 17 to 23° C. and a relative humidity of 70% to 90%.

[0009] More preferably, the method comprises placing uncolored mangoes in the green and ripe stage under the environmental conditions for 4 to 6 days.

[0010] Preferably, the red mango variety is 'Guifei' mango.

[0011] More preferably, the temperature for inducing red mango coloration is 20°C and the relative humidity is 80%.

[0012] Preferably, the method comprises: placing uncolored "Guifei" mangoes at the green and ripe stage under a temperature of 20°C, a relative humidity of 80%, and a UV-A light intensity of 112.5 μW·cm -2 or 220.3 μW·cm -2 or 351.3 μW·cm -2 , 6 days in an environment with a white light intensity of 10000Lux.

[0013] The beneficial effects of the present invention are as follows:

[0014] The present invention aims at harvesting uncolored red mangoes at the green and ripe stage, and adds three different light intensity gradients of low, medium and high UV-A to white light for induction treatment, wherein the low intensity UV-A is 101.3-123.8 μW·cm -2 , medium intensity UV-A is 198.3~242.3μW·cm -2 , high-intensity UV-A is 316.2~386.5μW·cm -2 , and the temperature, humidity and light in the induction environment are all controllable, and continuous treatment for a period of time can effectively induce the accumulation of anthocyanins, promote coloring, and improve the appearance quality, nutritional quality and commercial quality of mangoes. The method of the present invention is reasonably designed, simple to operate, safe and effective, has low requirements on equipment, can be operated on a large scale, and can be demonstrated and promoted for commercial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a photo of the coloration of the peel of the 'Guifei' mango fruit before and after treatment in an embodiment of the present invention; the circled part is the obvious colored area. DETAILED DESCRIPTION

[0016] In order to explain the present invention more clearly, the present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0017] Example

[0018] 1. Test Materials

[0019] The red mango variety 'Guifei' mango fruits were collected from the mango base of Hainan Fruit Island Agricultural Development Co., Ltd. (located in Yazhou District, Sanya City). The uncolored mango fruits in the green and ripe period (about 100 days after flowering) were selected and immediately transported back to the laboratory after purchase. The fruits with uniform size, no mechanical damage, no cracks, no diseases and insects, and no rot were selected for treatment.

[0020] 2. Test methods

[0021] Main equipment: artificial climate chamber (Shanghai Boxun, BIC-400, China);

[0022] The UV light source used was a 15W broad-spectrum ultraviolet (UV-A, 340nm) light source (Antoine, UV-A340, China), and the height from the fruit surface was 0.2 m;

[0023] The white light source used was a 30W LED light source (NVC, EGZZ1001, China).

[0024] 2.1.UV-A / white light treatment

[0025] Place the fruit in an artificial climate chamber and leave it for 6 days in the following environment:

[0026] (1) Temperature conditions: 20°C;

[0027] (2) Humidity conditions: relative humidity 80%;

[0028] (3) Lighting conditions:

[0029] Treatment 1 (low-intensity UV-A / white light treatment): Two UV light sources were used, and the UV-A intensity on the mango surface was about 112.5 μW·cm -2 , white light processing uses 10 white light sources with a light intensity of 10000Lux, Figure 1 It is recorded as 2UV-A / white light;

[0030] Treatment 2 (medium-intensity UV-A / white light treatment): Four UV light sources were used, and the UV-A intensity on the mango surface was about 220.3 μW·cm -2 , white light processing uses 10 white light sources with a light intensity of 10000Lux, Figure 1 It is recorded as 4UV-A / white light;

[0031] Treatment 3 (high-intensity UV-A / white light treatment): 6 UV light sources were used, and the UV-A intensity on the mango surface was about 351.3 μW·cm -2 , white light processing uses 10 white light sources with a light intensity of 10000Lux, Figure 1It is recorded as 6UV-A / white light.

[0032] The experiment was repeated in three groups, with five fruits in each group. After six days of treatment, the color difference, soluble solid content, soluble acid content, solid-acid ratio and hardness of the fruit were measured, and then the peel of the illuminated side of the fruit was separated with a peeler, immediately placed in liquid nitrogen, and packaged into bags according to the required amount of the measured indicators and stored at -80°C. The peel was used for the determination of anthocyanin content using spectrophotometry.

[0033] 2.2. White light treatment: The fruits were placed in an artificial climate chamber and treated with only 10 white light sources without UV-A treatment. The other conditions were the same as above.

[0034] 3. Results Analysis

[0035] 3.1. Fruit color analysis

[0036] like Figure 1 As shown, compared with the fruits at the starting point and placed under white light conditions for 6 days (control group), the mango peels treated with UV-A + white light for 6 days accumulated anthocyanins, and the color of the peel turned red (mainly concentrated in the circled area); and as the UV-A light intensity increased, the mango peel became redder.

[0037] As shown in Table 1, UV-A / white light treatment significantly changed the color parameters of the 'Guifei' mango peel. From the results of the significance analysis, the brightness L* values ​​of the UV-A / white light treatment were significantly lower than those of the control treatment except for the low-intensity UV-A / white light treatment, and the L* value of the fruit sample treated with high-intensity UV-A / white light was the lowest; the a* values ​​representing red and green (+ means reddish, - means greenish) of the UV-A / white light treatment were significantly higher than those of the control treatment, and the a* value of the fruit sample treated with high-intensity UV-A / white light was the highest; the b* values ​​representing yellow and blue (+ means yellowish, - means bluish) of the UV-A / white light treatment were significantly lower than those of the control treatment, and the b* value of the fruit sample treated with high-intensity UV-A / white light was the lowest.

[0038] Table 1 Effects of postharvest UV-A / white light treatment on color parameters of the fruit near the light side of ‘Guifei’ mangosteen

[0039]

[0040] Note: Different letters after the data in the same column indicate significant differences (α=0.05, HSD test).

[0041] 3.2. Analysis of anthocyanin content in peel

[0042] As shown in Table 2, after UV-A / white light treatment, the anthocyanin content in the fruit peel of the 'Guifei' mango near the light side was significantly higher than that in the control and 0-day samples, and the anthocyanin content of the fruit samples treated with high-intensity UV-A / white light was the highest. There was no significant difference in anthocyanin content between the control group and the 0-day group.

[0043] Table 2 Effects of postharvest UV-A / white light treatment on anthocyanin content in the pericarp of the near-light side of the 'Guifei' mango

[0044]

[0045] Note: Different letters after the data in the same column indicate significant differences (α=0.05, HSD test).

[0046] 3.3. Analysis of soluble solids, organic acids and solid-acid ratio

[0047] As shown in Table 3, the soluble solid content and solid-acid ratio of the treatment group and the control group showed an upward trend after 6 days of treatment, and the organic acid content of the control treatment and the low-intensity UV-A / white light treatment showed an upward trend, and the medium-intensity UV-A / white light treatment and the high-intensity UV-A / white light treatment showed a downward trend. After 6 days of treatment, except for the low-intensity UV-A / white light treatment, the soluble solid content and solid-acid ratio of the pulp of the other treatment groups were significantly higher than those of the control group, and the organic acid content was significantly lower than that of the control group, indicating that increasing the UV-A intensity can effectively reduce the organic acid content of mango fruit, increase the soluble solid content, and thus increase the solid-acid ratio.

[0048] Table 3 Effects of postharvest UV-A / white light treatment on soluble solids, organic acids and solid-acid ratio in ‘Guifei’ mango flesh

[0049]

[0050] Note: Different letters after the data in the same column indicate significant differences (α=0.05, HSD test).

[0051] 3.4. Fruit firmness analysis

[0052] As shown in Table 4, the fruit hardness of the treatment group and the control group showed a downward trend after 6 days of treatment. The fruit hardness of the medium-intensity UV-A / white light treatment and the high-intensity UV-A / white light treatment was significantly lower than that of the control group. There was no difference in the fruit hardness between the low-intensity UV-A / white light treatment and the control treatment, indicating that UV-A / white light treatment can promote fruit softening to a certain extent.

[0053] Table 4 Effects of postharvest UV-A / white light treatment on fruit firmness of 'Guifei' mango

[0054]

[0055] Note: Different letters after the data in the same column indicate significant differences (α=0.05, HSD test).

[0056] In addition to the environmental conditions used in the above embodiments, the experimental results show that the following environmental conditions are applicable: temperature 17-23°C; relative humidity 70%-90%; UV-A light intensity at low intensity (101.3-123.8 μW·cm -2 ), medium intensity (198.3~242.3μW·cm -2 ), high strength (316.2~386.5μW·cm -2 ), placing it under white light intensity of 9000-11000 Lux for 4-6 days can achieve the effect of inducing post-harvest coloring of red mangoes, and no further examples are given here.

[0057] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for inducing red mango coloring by using UV-A and white light, comprising placing uncolored mangoes in the green and ripe stage under environmental conditions for inducing red mango coloring for 4 to 6 days, wherein the environmental conditions are: the UV-A light intensity is selected from 101.3 to 123.8 μW·cm -2 、198.3~242.3μW·cm -2 and 316.2~386.5μW·cm -2 , white light intensity 9000~11000Lux, temperature 17~23℃, relative humidity 70%~90%.

2. The method according to claim 1, characterized in that The red mango variety is 'Guifei' mango.

3. The method according to claim 2, characterized in that The temperature for inducing red mango coloration was 20°C and the relative humidity was 80%.

4. The method according to claim 1, characterized in that: include: The uncolored 'Guifei' mangoes at the green stage were placed in a room with a temperature of 20°C, a relative humidity of 80%, and a UV-A light intensity of 112.5 μW·cm -2 or 220.3 μW·cm -2 or 351.3 μW·cm -2 , 6 days in an environment with a white light intensity of 10000Lux.

Images