System and method for post-harvest treatment of vegetables and fruits

Abstract

Vitamin C is one of the nutrient for which health claims are allowed. Tomato is, after onion, the most produced and consumed vegetable in the world. It is also for a number of country a very important crop. Increasing vitamin C in tomato can have major health impact. Vitamin C can be increasing with light during the growth of tomato. Disclosed are more practical solutions to increase the vitamin C during transport or storage, simplifying the process and allowing a better logistic in the tomato food chain.

Claims

1. A method of post-harvest light treatment for increasing the ascorbic acid content of fruit, the method comprising: providing a harvested unripe piece of fruit; irradiating at least part of the harvested unripe piece of fruit with radiation with a predetermined minimum radiation intensity and during a predetermined continuous radiation period; wherein at least 90% of the total number of photons of the radiation are in the range of 380-800 nm, wherein less than 10% of the total number of photons of the radiation are in the range of 700-800 nm, and wherein at least 30% of the total number of photons together provide a white light component of the radiation; wherein the average radiation intensity with which the piece of fruit is irradiated by said irradiating over the predetermined radiation period is at least 100 μmol/m.sup.2/s for the piece of fruit, and wherein the predetermined radiation period is at least 48 hours.

2. The method according to claim 1, wherein the piece of fruit is selected from the group consisting of a tomato, an apple and a bell pepper.

3. The method according to claim 1, wherein the piece of fruit is a tomato, and wherein the unripe piece of fruit comprises a tomato in the breaker stage or in a pre-breaker stage.

4. The method according to claim 1, wherein the predetermined radiation period is part of a given radiation period in the range of 96-216 hours, wherein the piece of fruit is irradiated during at least 80% of the given irradiation period and wherein the average radiation intensity with which the piece of fruit is irradiated over the given radiation period is in the range of 150-350 μmol/m.sup.2/s.

5. The method according to claim 1, wherein at least 90% of the total number of photons of the radiation are in the range of 380-700 nm, and wherein less than 5% of the total number of photons of the radiation is in the range below 380 nm.

6. The method according to claim 1, wherein the radiation is white light enriched with light having one or more colors selected from the group blue, green, yellow, orange, and red.

7. The method according to claim 1, further comprising detaching the unripe piece of fruit from its plant to provide said unripe piece of fruit detached from a plant.

8. The method according to claim 1, wherein the fruit is a cluster fruit, and wherein the unripe piece of fruit is provided detached from a cluster.

9. The method according to claim 1, comprising irradiating said at least part of the piece of fruit in a storage facility and/or comprising irradiating said at least part of the piece of fruit in a mobile transport device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The discloses post-harvest treatment is described in more detail and by way of non-limiting examples with reference to the accompanying drawings, wherein:

(2) FIG. 1 shows photon flux density (PFD) and phytochrome stationary state (PSS) of the irradiance treatments (A). Spectrum of the irradiance treatments (B) (i.e. blue plus yellow (which provide a white light component; here white light). Error bars represent a SEM (standard error of the mean), n=20.

(3) FIG. 2 shows average temperature of fruit under the irradiance treatments. Error bars represent a SEM, n=20.

(4) FIG. 3a shows total AsA levels of green (A), breaker (B) and red (C) of tomato fruit in the beginning of the experiment (broken line) and after 13 days in the irradiance treatments (solid line). Error bars represent a SEM, n=8. Ascorbate levels are in mg/100 g frewh weight (FW).

(5) FIG. 3b shows the normalized anthocyanins (A) and normalized vegetation (B) indices (NAI and NDVI, respectively) before and after 13 days in darkness and (highest) irradiance treatment (263 μmol m.sup.−2 s.sup.−1). Error bars represent SEM, n=5.

(6) FIG. 4 shows total soluble carbohydrate content of green and red fruit at the extreme irradiance treatments. Levels achieved after 13 days in the light treatment. Error bars represent SEM, n=8.

(7) FIG. 5 shows normalized anthocyanin and normalized vegetation indices (NAI and NDVI, respectively) before and after 13 days in the light treatments. Error bars represent SEM, n=5.

(8) FIG. 6 shows vitamin C content as a function of time upon illumination with LED lighting versus dark environment.

(9) FIG. 7 shows vitamin C of green harvested tomato (green line; i.e. upper line) versus red harvested tomato (red line; i.e. lower line) as a function of total irradiance at 7 days.

(10) FIG. 8 shows the response of various cultivars with irradiation of 300 umol/s/m.sup.2.

(11) FIG. 9 shows the effect of a longer term irradiation of up to 14 days with 600 μmol.Math.m.sup.−2.Math.s.sup.−1 on green and red tomatoes;

(12) FIG. 10 shows that vitamin C levels of detached tomato fruit increase with white LED light treatment (500 umol m.sup.−2 s.sup.−1) until the fruit changes coloration from green to red. Only green fruit respond to the light treatments. High vitamin C levels (fresh weights) are maintained for fruit kept in light. No increase occurs for fruit lift in darkness;

(13) FIG. 11 shows that for fruit harvested directly from the field we do not observe any differences in vitamin C for different developmental stages (green, breaker, pink and red stage). From the last two points we can exclude vitamin C going up due to enhanced ripening stimulated by light as during ripening vitamin C levels do not change considerably. Observed upregulation is an effect of white LED lighting;

(14) FIG. 12 shows several light intensities of white LED light which were tested for the same duration on green and red detached tomato fruit. Red fruit do not respond. Green fruit achieve higher vitamin C levels at higher light intensities with an optimum at 300 umol m.sup.−2 s.sup.−1 in this setup;

(15) FIG. 13 shows the results on five commercial tomato cultivars that were tested. All cultivars achieve higher levels of vitamin C when detached green fruit are treated with white LED light;

(16) FIG. 14 shows the impact of light quality treatments on total ascorbate levels of tomato fruit. Light quality treatments were established by monochromatic LEDs at 250 μmol/m.sup.2/s. In all treatments there was background radiation of white led supplied by LEDs at 100 μmol/m.sup.2/s;

(17) FIGS. 15a-15h show the influence of the irradiation over time on natural components in tomatoes (type antioxidants and vitamins). Note that here on the y-axis nanogram/gram FW is indicated;

(18) FIGS. 16a-16h show the influence of the composition of the radation on natural components in the tomatoe. Again, on the y-axis nanogram/gram FW is indicated;

(19) FIGS. 17a-17c show the progress of fruit development under white and far-red LED treatments and darkness. Light treatments were established by the use of monochromatic LEDs at 250 μmol/m.sup.2/s with 100 μmol/m.sup.2/s background white LED light. Developement indices relate to chlorophyll (NDVI) and lycopene (NAI) content and firmness of the fruit;

(20) FIG. 18 schematically depicts some aspects of the invention;

(21) FIGS. 19a-19c schematically depict some variants and embodiments.

(22) The schematic drawings are not necessarily on scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(23) A specific experiment to support the disclosed method for increasing vitamin C concentration (also referred to in this disclosure as AsA levels) in tomatoes is illustrated below.

(24) Materials and Methods

(25) Tomato fruit (Solanum lycopersicum cv. Komet) of three developmental stages (green, breaker and red) were harvested in December 2014 from a glasshouse in Bleiswijk, the Netherlands (52.0100° N, 4.5400° E). Fruits were selected according to colour indices, size and weight (NAI −0.6 to −0.5, NDVI −0.1 to −0.2, diameter 7 to 8 cm, weight 145 to 150 g and acoustic firmness 7 to 8). They were placed in environment controlled cabinets with constant temperature (18° C.), relative humidity (75%) and CO.sub.2 concentration (360 ppm). Relative humidity and CO.sub.2 concentration were measured using LI-1400 and LI-6400 respectively (Li-Cor Inc., Lincoln, Nebr., USA). The calyx was removed. In order to minimize water loss, fruit were placed with the calyx scar downwards. Five irradiance treatments were established with blue phosphorous coated LED lights (GreenPower LED research module, Philips, The Netherlands).

(26) Light was continuously supplied. The inner sides of the climate cabinets were covered with white neutrally reflective material, enhancing uniformity of light distribution. Irradiance measurements were conducted using a spectroradiometer (USB2000, Ocean Optics, Duiven, The Netherlands; calibrated against a standard light source). Phytochrome stationary state (PSS) was calculated according to equation 1 (N.sub.λ:photon flux at λ nm, σ.sub.rλ: photochemical cross-section of red absorbing phytochrome state, σ.sub.frλ; photochemical cross-section of far-red absorbing phytochrome state) Fresh weight measurements confirmed uniform water loss for all treatments (0.62% of initial fresh weight). Temperature of the fruit was monitored with k-type thermocouples attached to the lower side of the fruit (to avoid direct shortwave radiation) on TC-08 data loggers (Picotechnology LTD., Cambridge, UK) throughout the experiment. After 0 and 13 days AsA, dehydroascorbate (DHA) and soluble carbohydrates (fructose, glucose and sucrose) were measured by high performance liquid chromatography (HPLC: ICS-5000, Dionex Corporation, Sunnyvale, Calif.). Preparation of the samples for the HPLC took place as described in Davey et al. (2003) (Davey, M., Dekempeneer, E., and Keulemans, J. (2003). Rocket-powered high-performance liquid chromatographic analysis of plant ascorbate and glutathione. Analytical biochemistry 316, 74-81.). The progress of development was monitored by measuring changes in colour (hand-held photodiode array spectroradiometer, PA1101, CP, Germany) and firmness (AFS, AWETA, Nootdorp, The Netherlands). This hand-held spectroradiometer provides the normalized anthocyanin index (NAI) calculated according to remittance spectra at 570 and 780 nm and the normalized difference vegetation index (NDVI) calculated according to remittance spectra at 660 and 780 nm (equations 2 and 3). NAI and NDVI values correspond to lycopene and chlorophyll contents respectively.

(27) $\begin{array}{cc}\mathrm{PSS}=\left(\underset{300}{\overset{800}{.Math.}}{N}_{\lambda }{\sigma }_{r_{\lambda }}\right){\left(\underset{300}{\overset{800}{.Math.}}{N}_{\lambda }{\sigma }_{r_{\lambda }}+\underset{300}{\overset{800}{.Math.}}{N}_{\lambda }{\sigma }_{{\mathrm{fr}}_{\lambda }}\right)}^{-1}& \left(1\right)\\ \mathrm{NAI}=\frac{R780-R570}{R780+R570}& \left(2\right)\\ \mathrm{NDVI}=\frac{R780-R660}{R780+R660}& \left(3\right)\end{array}$

(28) A lower NAI implies low lycopene content and a higher NAI (thus) implies higher lycopene content; a lower NDVI implies low chlorophyll content and (thus) a higher NDVI implies higher chlorophyll content.

(29) One-way analysis of variance (ANOVA) was used to evaluate statistically significant effects of irradiance on total AsA. Significant differences between treatments means were evaluated with post hoc Tukey's honestly significant difference multiple comparison tests (P<0.05). Statistical analyses were carried out with the R software (R 3.0.1; R Project for Statistical Computing, Vienna, Austria).

(30) Treatments were established at 0 (dark), 8.1, 41.7, 124.4 and 263.4 μmol m.sup.−2 s.sup.−1 with the same spectral quality (FIG. 1). All irradiance treatments had the same phytochrome stationary state (PSS; Sager et al., 1988; (Sager, J., Smith, W., Edwards, J., and Cyr, K. (1988). Photosynthetic efficiency and phytochrome photoequilibria determination using spectral data. Transactions of the ASABE (American Society of Agricultural and Biological Engineers), 1882-1889.)) Blue phosphorous coated LEDs provide with a wide spectrum (FIG. 2) avoiding this way lack of possibly essential wavelengths for AsA regulation. The inner sides of the climate cabinet were covered with white neutrally reflective material, enhancing uniformity of light distribution. Irradiance measurements were conducted by spectrometer (USB2000, Ocean Optics, Duiven, The Netherlands; calibrated against a standard light source). Fresh weight measurements ensured uniform water loss for all treatments. Temperature of the fruit was monitored with k-type thermocouples on TC-08 data loggers (Picotechnology LTD., Cambridge, UK) throughout the experiment. Maximum temperature differences between treatments were less than 1° C. (FIG. 3a). AsA, dehydroascorbate (DHA) and soluble carbohydrates (fructose, glucose and sucrose) were measured in high performance liquid chromatography system (ICS-5000, Dionex Corporation, Sunnyvale, Calif.). Preparation of the samples for the HPLC took place as described in Davey etal. (2003). The progress of development was monitored through changes in colour (hand-held photodiode array spectrometer, PA1101, CP, Germany) and firmness (AFS, AWETA, Nootdorp, The Netherlands). This device provides the normalized anthocyanin index (NAI) calculated according to remittance spectra at 570 and 780 nm and the normalized difference vegetation index (NDVI) calculated according to remittance spectra at 660 and 780 nm. The duration of the treatment was 13 days.

(31) Results and Discussion

(32) Total AsA levels were measured after 13 days of irradiance treatments. Accumulation of AsA in tomato fruit increases when fruit are treated with higher irradiances. This increase is different for each developmental stage. Green fruit were found to be the most responsive with a significant increase of 32% in comparison to red fruit (5% not significant). Green fruit eventually achieved higher absolute levels of total AsA than red fruit. The dose-response curve of AsA to irradiance for green fruit follows an exponential trend indicating that the saturation point of AsA to irradiance is probably at higher light intensities. Comparing the lowest irradiance level (8.1 μmol m.sup.−2 s.sup.−1) with the darkness treatment, no significant differences were observed.

(33) At the beginning of the treatment (t=0 days) tomatoes were at the mature green stage (full sized). By the end of the treatment (t=13 days) fruit reached a red ripe stage in all light treatments as confirmed by the NAI and NDVI (dark control and the highest light treatment were the same; FIG. 3b). This indicates that light treatments did not accelerate the rate of development of the fruit in comparison to the dark treatment. The similar ripening of dark and light treated tomatoes was also reflected in similar loss of firmness as measured by acoustic firmness measurements (data not shown).

(34) Progress of development results in a slight increase in AsA content in all developmental stages. That could be attributed to increased activity of the secondary pathway due to ripening. For each developmental stage both NAI and NDVI were the same between darkness and the highest developmental treatment (FIG. 4). This indicates that light treatments did progress development of the fruit in comparison to the dark treatment. This was also confirmed by acoustic firmness measurements (data not shown).

(35) Irradiance is the abiotic factor with the most pronounced effects on AsA found in plant tissue. These effects have been confirmed for both leaves and fruit (Massot et al., 2012). In this work we prove that tomato fruit that have been removed from the plant are still responsive to irradiance treatments by increasing their levels of AsA (FIG. 3a). This allows to (a) understand better AsA regulation off and on the plant and (b) develop a system for postharvest improvement of AsA in fruit. Optimal AsA levels are achieved at higher than 263 μmol m.sup.−2 s.sup.−1.

(36) Irradiance levels that do not affect physiological processes (respiration photosynthesis; lowest irradiance treatment—8 μmol m.sup.−2 s.sup.−1) directly linked to AsA regulation did not result in AsA accumulation. Therefore, regulation of AsA via both gene expression signalling and physiological processes occurs after an irradiance threshold.

(37) Total carbohydrates did not differ significantly between the extreme irradiance treatments and the extreme developmental stages (FIG. 4). This indicates that regulation of AsA by light is not done via the substrate but probably other related physiological processes (respiration and/or photosynthesis) or direct signalling of light. The extremely low absolute levels of carbohydrates observed might be a limitation for further upregulation of AsA by light.

(38) FIG. 6 shows a 5 times increase of the vitamin C content as a function of time upon illumination with LED lighting. After 9 days of illumination, no further increase is observed.

(39) FIG. 7 shows the increase in vitamin C of green harvested tomato (green line) versus red harvested tomato (red line) as a function of total irradiance at 7 days.

(40) FIG. 8 shows the response of various cultivars with irradiation of 300 umol/s/m2. This irradiation is the most optimum for most cultivars.

(41) FIG. 9 shows the effect of a longer term irradiation of up to 14 days with 600 μmol.Math.m.sup.−2.Math.s.sup.−1 on green and red tomatoes. Vitamin C contents of above 50 mg/100 gram FW are observed for green harvested tomatoes.

(42) A Commercial System for Postharvest Enhancement of AsA

(43) Light is a key component of a potential system for the postharvest upregulation of AsA. These results consist the basis of further investigation of light effects on AsA before the design of a relevant system. The optimum irradiance level for AsA have to be specified also in respect to the duration of the treatment (Labrie and Verkerke, 2012). Light quality has also an effect on AsA levels of plant tissue. Higher R:FR results in more AsA (Bartoli et al., 2009). Spectral bands that promote related physiological processes might also be beneficial (e.g. light colours that promote photosynthesis). Tomato fruit to be treated should be selected in respected top the following criteria: (a) cultivars that are considerably responsive, (b) fruit with considerable carbohydrate content so that no substrate limitations will exist and (c) appropriate developmental stages (as shown in this experiment). Green fruit are the most responsive (this paper). Certain supply chains around the world have tomato fruit harvested green to minimize loss during transportation. Finally, storage and transportation temperature is also a critical control point as temperature also affects AsA levels in plants. LED lighting is a technology of high potential for such application. It is not only energy efficient (avoiding temperature side effects) but also allows the selective application of specific spectra. LEDs come in compact modules and allows easy installation in several parts of the production chain (e.g. rooms and trucks). Due to low heat emissions fruit can be placed very close to the LED lamps.

CONCLUSIONS

(44) Postharvest irradiance treatments increase AsA levels of tomato fruit. Green fruit are more responsive than fruit at later developmental stages (breaker and red). Low levels of soluble carbohydrates may consist a significant limitation for upregulation of AsA by irradiance.

FURTHER EXPERIMENTS

(45) Vitamin C levels of detached tomato fruit increase with white LED light treatment (500 umol m.sup.−2 s.sup.−1) until the fruit changes coloration from green to red. This is depected in FIG. 10. Only green fruit respond to the light treatments. High vitamin C levels are maintained for fruit kept in light. No increase occurs for fruit lift in darkness (this is depected in FIG. 10.).

(46) For fruit harvested directly from the field we do not observe any differences in vitamin C for different developmental stages. From the last two points we can exclude vitamin C going up due to enhanced ripening stimulated by light as during ripening vitamin C levels do not change considerably. Observed upregulation is an effect of white LED lighting. This is depicted in FIG. 11.

(47) Several light intensities of white LED light were tested for the same duration on green and red detached tomato fruit. Red fruit do not respond. Green fruit achieve higher vitamin C levels at higher light intensities with an optimum at 300 umol m.sup.−2 s.sup.−1 in this setup. This is depicted in FIG. 12. In combination with the previous experiment the irradiance optimum should be defined between 200-600 m.sup.2 s.sup.−1, especially 300-500 μmol m.sup.−2 s.sup.−1.

(48) Five commercial tomato cultivars were tested. All cultivars achieve higher levels of vitamin C when detached green fruit are treated with white LED light. This indicates a universal effect for tomato. There more and less responsive cultivars. This is depicted in FIG. 13. For these experiments, 300 μmol m.sup.−2 s.sup.−1 24 hours each day during 7 days was applied.

(49) In some experiments, specific light treatment protocols were applied. These included white light (white light component), and on top thereof colored light was added (e.g. white LEDs in combination with LEDs emitting colored light)(colored light component). The options used, and the results on the generation of ascorbic acid are shown in FIG. 14. The initional ascorbic acid content and content after a dark period are the same. Further, as can be seen, the differences between the types of light are relatively small, though far read has a significantly lower impact than white light, or white light enriched with blue. The recipies used for FIG. 14 are indicated in below table (with the values of the light treatments in μmol m.sup.−2 s.sup.−1):

(50) TABLE-US-00001 Treatment White Color Total Dark 0 0 0 Red 100 250 350 Blue 100 250 350 Far Red 100 250 350 Green 150 200 350 White 350 0 350

(51) All light quality treatments improved vitamin C levels of detached tomato fruit. Different light colors seem to have a similar effect with blue and far-red being the extreme ones. All light colors improve vitamin C levels, while far—red is a significantly less effective. Here, the irradiation was 24 hours a day for seven days. In the examples above, about 30% of the radiation is provided by the white light component (for red, blue, far red, and green).

(52) Other natural compounds were investigated as well. The concentrations after constant light treatment (24 h each day), with 500 μmol m.sup.−2 s.sup.−1 are shown in FIGS. 15a-15h. In those experiments, white light was used (without far red or UV).

(53) In the same experiments, other natural compounds were checked as well. The results are displayed in FIGS. 16a-16h. From these data, the following can be concluded: blue enriched white light (and optionally blue light only), can be used to enrich the fruit with lutein (FIG. 16a); red enriched white light (and optionally blue light only), can be used to enrich the fruit with zeaxanthin (FIG. 16b); blue and/or green enriched white light (and optionally green and/or blue light only), can be used to enrich the fruit with α-carotene (FIG. 16c); blue enriched white light (and optionally blue light only), can be used to enrich the fruit with (62-carotene (FIG. 16d); green and/or far red enriched white light (and optionally green and/or far red light only) can be used to enrich the fruit with lycopene (FIG. 16e); and blue enriched white light (and optionally blue light only), can be used to enrich the fruit with α-tocopherol (FIG. 16g).

(54) In yet a further experiment, NDVI, NAI and firmness were measure in dependence of illumination 24 h a day with a light intensity of 350 μmol m.sup.−2 s.sup.−1 with different light types (250 far red+100 white; 350 white only), in comparison to no illumination. The data are displayed in FIGS. 17a-17c. Far red radiations seems to promote the synthesis of lycopene (see also above). For fruit treated with far red we observed not only higher final lycopene content (results above) but also a quicker improvement for red color (NAI). Substantially no effect on green was observed (NDVI). The normalized difference vegetation index (NDVI) is a simple graphical indicator that can be used to analyze remote sensing measurements, typically but not necessarily from a space platform, and assess whether the target being observed contains live green vegetation or not. As indicated above, the normalized difference vegetation index NDVI=(I780−I660)/(I780+I660) and the Normalized anthocyanin index NAI=(I780−I570)/(I780+1570).

(55) In view of those results, the the following is concluded: Monochromatic light alone is not ideal to induce changes in the nutrient (vitamins) of the tomato fruit; White light from white LEDs without UV and IR parts is the best for inducing a significant increase of vitamin C and other compounds; Far red light has a particular role. This light (700-800 nm) is not very efficient to increase most of nutrients (vitamin C, Lutein, Zeaxanthin, a- and b-carotenes, a- and d-tocopherol). However it seems that for Lycopene, this wavelength plays a particular role. Lycopene is also contributing to the coloration of the tomato as well as human health benefits. It is therefore maybe good to include a small dose of farred (1 to 20% or the total PAR light provided from the white LEDs); Light should especially be provided 24 h per day for a minimum of about 96 hours, such as especially at least 168 hours, like 7 days and a maximum of about 240 hours, such as especially at maximum 10 days; White light appears to be better than sunlight because the UV compounds and infrared parts are not included; 24 h illumination at a given intensity is needed to achieve significant increase of nutrients (about 300 μmol/s/m.sup.2 being the most efficient intensity).

(56) FIG. 18 scheatmcially depicts a device 200 for ripening a piece of fruit 100, the device 200 comprising a light source 10 configured to generate radiation 11. Especially at least 90% of the total number of photons of the radiation 11 is in the range of 380-800 nm. Further, especially less 10% of the total number of photons of the radiation 11 are in the range of 700-800 nm. Yet further, especially at least 10% of the total number of photons together provide a white light component 11a of the radiation 11, such as with a first LED light source 10a. Here, the light source can provide white light 11a and also colored light 11b. Together they form the radiation 11. Note that only part of the piece of fruit 100 is irradiated with the radiation 11. In embodiments, the method may include turning one or more times the piece of fruit 100. The colored light 11b (component) may be provided with a second LED light source.

(57) In specific embodiments the device 200 is configured to generate said radiation 11 with a predetermined intensity of at least 100 μmol/m.sup.2/s at a distance L from said light source 10, wherein said distance is selected from the range of 0.1-3 m. Here, the area (“m.sup.−2” or “/m.sup.2”) indicates the area of the piece of fruit that receives the radation.

(58) FIGS. 19a and 19b schematically depict embodiments comprising irradiating said at least part of the piece of fruit 100 in a storage facility 31 and/or comprising irradiating said at least part of the piece of fruit 100 in a mobile transport device 32. FIG. 19a schematically depicts a storage facility 31 as space 30 wherein the fruit is irradiated with radation 11. For instance, the storage facilty may be a ripening cell at an auction site. FIG. 19b schematically depicts a mobile transport device 32 as providing a space 30 wherein the fruit is irradiated with radation 11.

(59) FIG. 19c schematically depicts an embodiment of the device 200 wherein the device comprises a rack 220 configured to host a plurality of support elements 230 over each other, wherein each support element 230 are configured to support one or more pieces of fruit 100. The device 200 comprises a plurality of said light sources 10 dedicated to the plurality of support elements 230, respectively. Light sources may be configured to a back side of a support. The supports are configured at distances from each other, allowing the fruits and light source be arranged and configured on and over the respective support, respectively. This device may e.g. be based on the device described in U.S. Pat. No. 8,181,387, which is herein incorporated by reference. Choosing the support element 230 at a distance L wherein the support element receives the indicated minimum radiation intensity will automatically provide the required minimum radiation intensity to the piece of fruit in or on the support element.

(60) The term “substantially” herein, such as in “substantially all light” or in “substantially consists”, will be understood by the person skilled in the art. The term “substantially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially may also be removed. Where applicable, the term “substantially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” includes also embodiments wherein the term “comprises” means “consists of”. The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term “comprising” may in an embodiment refer to “consisting of” but may in another embodiment also refer to “containing at least the defined species and optionally one or more other species”.

(61) Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

(62) The devices herein are amongst others described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation or devices in operation.

(63) It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

(64) The invention further applies to a device comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

(65) The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.