IMPROVEMENT OF VITAMIN D3 ENRICHEMENT IN COLEOPTERIOR LARVAE PROCESSED BY ULTRAVIOLET TREATMENT AND ASSOCIATED FOOD POWDER

Abstract

The present invention relates to a method for preparing a beetle powder comprising a light treatment step in which at least one light source emits ultraviolet rays of the UVB type towards transformed beetle larvae, said ultraviolet rays of the UVB type having an irradiance at the level of the powder greater than 80 µW / cm².

Description

Title of the invention: IMPROVEMENT OF VITAMIN D3 ENRICHEMENT IN PROCESSED COLEOPTERIOR LARVAE BY AN ULTRAVIOLET TREATMENT AND ASSOCIATED FOOD POWDER technical field

[0001] The present invention relates to the field of the food industry.

[0002] The object of the present invention relates more specifically to the preparation of a food powder based on beetles.

[0003] One of the objects of the present invention is to improve the vitamin D3 enrichment of a powder derived from beetle larvae.

[0004] The present invention will thus find many applications, particularly in the food industry, and especially for human food, reptile food, animal food (PetFood / PetCare / Dietary Supplement) or fish farming. Previous art

[0005] Vitamin D3 has important properties for the body.

[0006] By vitamin D3, we mean here cholecalciferol.

[0007] In humans, this vitamin D3 contributes in particular to maintaining normal blood levels of calcium and phosphorus absorbed by the intestine. It strengthens the immune system and improves cognitive function.

[0008] Vitamin D3 also plays an essential role in maintaining bones and skeletal muscles in humans and pets such as dogs.

[0009] For example, it is used as a supplement to calcium to prevent osteoporosis in the elderly.

[0010] In reptiles, vitamin D3 allows optimal assimilation of calcium and mineralization of bones.

[0011] It is now known that 50% of healthy adults suffer from a deficiency in vitamin D3.

[0012] The daily requirement for vitamin D3 is 15 pg for adults and can increase to 20 pg in people over 70 years of age.

[0013] Traditionally, dietary sources of vitamin D3 come primarily from fish, particularly through fish oils, fillets, or livers. However, fish is a declining resource, which is therefore becoming increasingly expensive.

[0014] Vitamin D3 extracted from boreal lichen or synthesized from lanolin can also be found in supplement form.

[0015] Foods rich in vitamin D3 are therefore present in reduced quantities; the demand for vitamin D3 is growing rapidly.

[0016] Food industry players are therefore concentrating a lot of energy on finding solutions to produce this vitamin D3 in a sustainable and responsible way.

[0017] The prior art is known to know the document WO2019229332 Al belonging to the Applicant.

[0018] This document proposes a method for manufacturing food powder rich in vitamin D3 based on beetles.

[0019] In this document, an ultraviolet treatment, called UV treatment, is proposed more specifically during the growth phase of Tenebrio Molitor or Alphitobius Diaperinus type larvae.

[0020] Such UV treatment during the growth phase of the larvae allows for a significant synthesis of vitamin D3.

[0021] Indeed, the results obtained with the enrichment technology proposed in document WO2019229332 A1 show that, without UV treatment, the larvae contain little or no vitamin D3 (between 0 and 2 pg / 100 g dry weight), whereas with UV treatment during the larval growth phase, a maximum average vitamin D3 level of approximately 50 pg / 100 g dry weight is obtained in the larva. These live larvae rich in vitamin D3 then allow, after the processing phase, the production of beetle powders or beetle larvae rich in vitamin D3.

[0022] The Applicant submits however that, from an industrial point of view, the implementation of the solution proposed in document WO2019229332 Al remains complex.

[0023] Indeed, according to the technical teaching of this document, the UV treatment is carried out directly on live larvae during their larval growth phase.

[0024] This gives rise to several problems which can severely impair the productivity of a farm and make it difficult to industrialize the UV treatment process.

[0025] The Applicant submits firstly that UV treatment on live larvae can generate a mortality rate of larvae ten times higher than that observed on larvae in the absence of UV treatment, particularly when the light source is placed at a distance of less than 25 centimeters from the live larvae.

[0026] Tests show that the mortality rate of 12-week-old larvae that underwent UV treatment (25 W lamp, UVB index 200) for 10 days at a distance of 25 centimeters from the light source is 0.1%, whereas it is 0.01% without this light treatment.

[0027] The Applicant submits secondly that the surface area required to carry out this type of UV treatment is significant.

[0028] To obtain a vitamin D3 synthesis of 50 pg / 100 g on a dry weight basis of larvae, a 25W UVB lamp (UVB index 200) must be placed 25 centimeters from the container holding the larvae for 10 days. These containers measure 56 centimeters x 38 centimeters x 17 centimeters. This configuration minimizes the mortality rate while maximizing the vitamin D3 synthesis rate.

[0029] It is therefore very costly in terms of time but also in terms of surface area since, under the conditions described above, a structure of 125 centimeters x 200 centimeters x 30 centimeters only produces 10.5 kilograms of live larvae (i.e. 3.75 kilograms of powder) every 10 days.

[0030] The Applicant therefore submits that the solutions in the prior art are not yet fully satisfactory for the industrialization of the manufacture of a food-grade beetle powder rich in vitamin D3. It would indeed be advantageous to find a reliable industrial solution that would significantly increase the concentration of vitamin D3 in the processed beetle larvae while reducing manufacturing costs.

[0031] Object of the invention

[0032] The present invention aims to improve the situation described above.

[0033] The present invention is more particularly aimed at addressing the various disadvantages mentioned above by proposing an effective and easy-to-implement industrially applicable solution to significantly increase the vitamin D3 level in beetle powder, all while limiting industrial costs.

[0034] The object of the present invention relates in a first aspect to a method for preparing a beetle powder enriched in vitamin D3 comprising a light treatment step during which at least one light source emits ultraviolet rays of the UVB type towards transformed beetle larvae.

[0035] According to the invention, ultraviolet rays of the UVB type have an irradiance at the level of the powder greater than 80 pW / cm2.

[0036] By emitting such UVB rays with an irradiance greater than 80 pW / cm2, it was found that it was possible to significantly reduce the UV treatment period and obtain a surprising increase in the vitamin D3 level.

[0037] This reduction in exposure time makes it possible to optimize the process, reduce costs and facilitate industrialization.

[0038] Preferably, the irradiance of the emitted UVB rays is between 80 and 1000 pW / cm2.

[0039] Preferably, the irradiance of the emitted UVB rays is between 150 and 250 pW / cm2.

[0040] Preferably, the irradiance of the emitted UVB rays is between 170 and 200 pW / cm2.

[0041] UV pre-treatment steps (the transformation):

[0042] Here, by transformed larvae, we mean beetle larvae that have undergone at least one killing process.

[0043] Advantageously, the process according to the present invention includes, prior to the light treatment step, a step of transformation of beetle larvae comprising a slaughter of said larvae.

[0044] Preferably, the transformation step is carried out on beetles in the larval stage.

[0045] According to a first variant, this slaughter is carried out by a cold thermal treatment.

[0046] Cold heat treatment means, for example, exposing beetle larvae to temperatures below 4°C for a period of more than 10 minutes.

[0047] According to a second variant, this transformation step is carried out by a hot heat treatment.

[0048] By hot heat treatment, we mean for example the exposure of beetle larvae to temperatures above 40 °C for a period of more than 15 seconds in water (boiling) or more than 30 minutes in heated air.

[0049] In a particular embodiment, it can be provided that, during the slaughter stage, the larvae are positioned in water with a temperature between 50 and 120°C, preferably between 85°C and 110°C, and even more preferably between 90°C and 100°C.

[0050] This is also referred to as scalding.

[0051] Such a slaughter technique by boiling proves to be effective and makes it possible to preserve the nutritional properties of the beetles and to reduce the bacterial load of the larvae.

[0052] Preferably, this boiling is carried out for a boiling time of between 30 seconds and 10 minutes, preferably between 1 and 5 minutes.

[0053] According to a third variant, the killing step can also be done by exposing the beetle larvae to microwaves, for example for at least 10 seconds.

[0054] Advantageously, the transformation phase includes after slaughter a dehydration (or cooking) step aimed at obtaining a water activity (AW, Activity of Water) rate of the powder < 0.7.

[0055] For this dehydration, microwave treatment can be provided.

[0056] Microwave treatment means exposing beetle larvae to microwaves, for example for at least 10 seconds.

[0057] For this dehydration, one can also provide, as an alternative or complementary measure, a heat treatment of the slaughtered larvae.

[0058] During this heat treatment of the larvae for dehydration, the slaughtered larvae are therefore placed in an environment between 40 and 250 °C, preferably between 50 and 150 °C, and preferably for a treatment time of between 1 and 24 hours, so that the slaughtered larvae exhibit: - between 2 and 15% water, more preferably between 3 and 8% water, and / or - water activity (AW) less than 0.7.

[0059] Preferably, during heat treatment, the transformed larvae are arranged in a thickness of between 1 and 100 millimeters, preferably between 5 and 15 millimeters.

[0060] Optionally, the transformed larvae may undergo grinding and / or pressing.

[0061] Preferably, the processing step includes, after felling, grinding the larvae to obtain beetle powder.

[0062] It should be noted here that grinding the larvae after dehydration improves vitamin D3 synthesis performance after UV treatment. This post-dehydration step, however, remains optional.

[0063] After dehydration and grinding, a powder of beetles is obtained.

[0064] By beetle powder, we mean a dry powder (AW < 0.7) consisting, for example: - either whole Tenebrio molitor larvae that have undergone a thermal drying process and grinding; - either whole larvae of Alphitobius diaperinus that have undergone a thermal drying process and grinding; - either a mixture of larvae of these two species having undergone a thermal drying process and grinding; - either a fraction of whole Tenebrio molitor larvae that have previously undergone a pressing process followed by a thermal drying process and grinding; - either a fraction of whole Alphitobius diaperinus larvae that have previously undergone a pressing process followed by a thermal drying process and grinding; - either a mixture of larval fractions of these two species having previously undergone a pressing process followed by a thermal drying process and grinding.

[0065] In a particular embodiment, the transformation step includes a first sieving of the larvae to remove residues such as excrement or possible food remains.

[0066] Such sieving remains optional, however. Its sole purpose is to clean the larvae before slaughter.

[0067] Preferably, the transformation step includes a fasting period of 24 to 48 hours. Such a fasting period prevents the formation of new excrement. Therefore, implementing such a fasting period remains optional within the scope of the present invention.

[0068] Optionally, the fasting step is followed by a second sieving.

[0069] Advantageously, the processing step includes prior to slaughter cold stunning between -18°C and +4°C.

[0070] Preferably, the cold stunning step is carried out for a stunning duration of between 1 and 5 minutes. Slaughter can be carried out without stunning; such stunning therefore remains optional to be implemented within the framework of the present invention.

[0071] Steps of UV treatment (vitamin D3 synthesis):

[0072] Advantageously, the ultraviolet rays emitted by at least one light source towards the transformed beetle larvae during the light treatment step are: - of the UVB type and consist of electromagnetic radiation with a wavelength between 280 nm and 320 nm, and / or; - of the UVA type and consist of electromagnetic radiation with a wavelength between 320 nm and 400 nm.

[0073] Preferably, during the light treatment step, at least one light source is positioned at a determined distance from the beetle larvae, preferably between 1 and 100 centimeters, and preferably between 5 and 20 centimeters.

[0074] The intensity of UV light sources decreases with increasing distance from them. The amount of vitamin D3 synthesized is dependent on the amount of UVB received per unit of time.

[0075] Advantageously, at least one light source has a radiation power between 13 and 125 Watts, preferably between 20 and 50 Watts.

[0076] Advantageously, it is envisaged that, during the light treatment step, at least one light source emits ultraviolet rays towards the transformed beetle larvae over a treatment range of between 10 seconds and 24 hours, preferably between 1 and 7 minutes, preferably between 2 and 5 minutes.

[0077] Advantageously, this treatment range is carried out continuously or cumulatively.

[0078] It is understood here that a 3-minute UV treatment can be carried out, for example, continuously for 3 minutes or in 3 successive 1-minute periods, each separated, for example, by rest periods of a few minutes. Advantageously, it is envisaged that, during all or part of the light treatment step, the transformed beetle larvae are maintained in an environment with a substantially constant temperature between 15 and 35°C, preferably between 22 and 26°C.

[0079] Vitamin D3 synthesis is optimized in the presence of temperatures above 20 °C.

[0080] The object of the present invention relates, according to a second aspect, to a beetle powder obtained by implementing the preparation process as described above.

[0081] The object of the present invention relates according to a third aspect to the use of a beetle powder as described above for human or animal food.

[0082] Preferably, the powder is used as an ingredient or food supplement.

[0083] Other advantageous uses may be envisaged such as feeding reptiles or fish. Figures

[0084] Other features and advantages of the present invention will become apparent from the description below, with reference to the attached Figures 1 to 4A-4D, which illustrate an example of an embodiment without being limiting in any way and on which:

[0085] [Fig.1]

[0086] Fig. 1 is a graph representing the concentration of vitamin D3 in several samples of beetle larvae that have undergone UV light treatment with an exposure time of eight hours;

[0087] [Fig.2]

[0088] Fig. 2 is a graph representing the evolution of the concentration of vitamin D3 of several samples of beetle larvae that have undergone UV light treatment as a function of time;

[0089] [Fig.3]

[0090] Fig. 3 is a graph representing the evolution over time of the concentration of vitamin D3 for several different beetle powder samples subjected to UV sources having a specific UVB irradiance;

[0091] [Fig.4A]

[0092] Fig. 4A includes a graph illustrating a first example of the evolution of an oxidation indicator of beetle powder as a function of UVB treatment duration and UVB irradiance level;

[0093] [Fig.4B]

[0094] Fig. 4B includes a graph illustrating a second example of the evolution of an oxidation indicator of beetle powder as a function of UVB treatment time and UVB irradiance level;

[0095] [Fig.4C]

[0096] Fig. 4C includes a graph illustrating a third example of the evolution of an oxidation indicator of beetle powder as a function of UVB treatment time and UVB irradiance level;

[0097] [Fig.4D]

[0098] Figure 4D includes a graph illustrating a fourth example of the evolution of a beetle powder oxidation indicator as a function of UVB treatment time and UVB irradiance level. Detailed description

[0099] An example of the realization of a preparation of a beetle powder rich in vitamin D3 will now be described in what follows with joint reference to figures 1 to 4A-4D.

[0100] For the record, the powder preparation which will be described here aims to develop a technique to significantly increase the level of vitamin D3 in powders based on beetles, and in particular beetles of the type Tenebrio molitor and / or Alphitobius diaperinus.

[0101] Unlike techniques involving UV treatment on live beetles (for example, fresh beetle larvae) as proposed in document WO2019229332, one of the concepts underlying the present invention is to carry out a UV treatment consisting of emitting UVB rays with an irradiance greater than 80 pW / cm2 onto transformed larvae.

[0102] Here, transformed larvae are meant beetle larvae that have undergone at least one slaughter.

[0103] In the example described here and used in the various experiments, larvae selected from the following species are used: Tenebrio Molitor and / or Alphitobius Diaperinus.

[0104] It will be understood that other experiments not described here have been carried out with other species and show equivalent results.

[0105] It should be noted here that the growth phase of the larvae is not described in this document because the invention relates to UV treatment (and incidentally to the phase transformation), the phases prior to breeding are not part of the present invention.

[0106] Transformation phase:

[0107] In a particular embodiment of the present invention, the transformation phase is carried out in the following manner.

[0108] Between the 6th and 14th week of growth, more preferably between the 10th and 13th week of growth, the larvae are sieved to remove excrement.

[0109] The sieved larvae are then placed in a plastic tray for a fast of 24 to 48 hours.

[0110] After fasting, the larvae are sifted again to remove excrement.

[0111] The larvae are placed in water between 85°C and 100°C for slaughter for 1 to 4 minutes. This is referred to as hot thermal slaughter.

[0112] During this transformation, a cold stunning step between -18°C and +4°C for several minutes is also planned just before slaughter.

[0113] After slaughter, the larvae undergo heat treatment at a temperature between 50 and 150°C for a period of between 1 hour and 24 hours depending on the temperature used.

[0114] The larvae obtained contain between 2 and 15% water, more preferably between 3 and 8% water and a water activity of less than 0.9, more preferably less than 0.7.

[0115] A grinding phase may be carried out. The term powder here refers to any reduction into an element smaller than 3 millimeters of whole insects that have previously undergone heat treatment in their larval or pupal stage, or only of a morphological part of these insects.

[0116] It is understood here that this is a description of a particular embodiment of this transformation phase.

[0117] Such an implementation makes it possible to obtain effective results. It will be understood, however, that a person skilled in the art may consider other implementations for transforming beetle larvae.

[0118] It should also be noted here that powder manufacturers will not necessarily carry out this slaughtering phase and may obtain their supplies from a beetle breeder who will deliver beetle larvae that have already been processed (or slaughtered). In this case, the powder manufacturer will proceed directly to the enrichment (or UV treatment) phase to enrich the powder with vitamin D3.

[0119] For these reasons, it will be understood that the transformation examples given above are purely illustrative and do not form an integral part of the invention. - 1 m series of tests:

[0120] UV treatment phase:

[0121] In this example we have transformed larvae.

[0122] In this example, these processed larvae are in the form of dehydrated and ground larvae or of whole dehydrated, unground larvae.

[0123] In this example, it is planned to apply a UV treatment to these transformed larvae, which is characteristic of the present invention.

[0124] In this example, this UV treatment step takes place in a specific room.

[0125] In the embodiment of the present invention, this room is maintained in ambient conditions allowing the transformed beetles to be maintained in an environment with:

[0126] - a substantially constant temperature between 15 and 35°C, preferably between 22 and 26°C; and

[0127] - a substantially constant humidity level between 20 and 80% relative, preferably between 30 and 40%.

[0128] This controlled management of ambient parameters (temperature and humidity) allows for a better yield in the synthesis of vitamin D3.

[0129] A person skilled in the art could, however, consider other similar ambient conditions.

[0130] In this example, the UV treatment lasts between 2 minutes and 72 hours continuously.

[0131] It should be noted that it is possible to reduce this treatment period even further.

[0132] In the example described here, we therefore seek to enrich beetle larvae transformed by UV treatment with vitamin D3.

[0133] Such a UV treatment employs at least one light source of the ultraviolet source (or UV source) type which emits ultraviolet rays towards transformed beetle larvae.

[0134] Preferably, the UV source is kept in a vertical position above the beetle powder or whole beetles.

[0135] In this example, the ultraviolet rays emitted by the UV source towards the beetle larvae are: - of the UVB type and consist of electromagnetic radiation with a wavelength between 280 nm and 320 nm, and / or - of the UVA type and consist of electromagnetic radiation with a wavelength between 320 nm and 400 nm.

[0136] It should be noted here that the emission of light in the visible range has no effect on the synthesis of vitamin D3.

[0137] In the example described here, the UV source is positioned, during the light treatment phase, at a determined distance from the beetle larvae of the order of 2 to 100 cm, preferably between 10 and 30 cm.

[0138] In this example, the UV source has a radiation power between 13 and 125 Watts, preferably between 20 and 50 Watts.

[0139] In this first example, the UVB rays emitted by the UV source have an irradiance of approximately 75 pW / cm2.

[0140] Optionally, after this UV phase, a second heat treatment between 40 and 200°C, preferably between 60 and 100°C for 1 hour to 24 hours can be carried out.

[0141] Results

[0142] Initial results obtained from the various studies and tests carried out are particularly interesting:

[0143] [Tables 1] Results: Document WO2019229332 A1 Results Vitamin D3 concentration after UV treatment on live larvae for 5 days. 1 Vitamin D3 concentration after UV treatment on transformed larvae not ground into powder for 5 days. 1 Vitamin D3 concentration after UV treatment on transformed larvae ground into powder for 5 days. 1 24 pg / 100 g dry weight (=9600 IU / kg) 97 pg / 100 g dry weight (=38800 IU / kg) 204 pg / 100 g dry weight (=81600 IU / kg)

[0144] 1 The live larvae and the transformed larvae are located 25 cm from the source bright and placed in trays measuring 57 centimeters x 38 centimeters x 17 centimeters. The thickness of the live and transformed larvae is a maximum of 1 cm.

[0145] These results are confirmed and amplified by further series of tests, which will be detailed later in the description. These additional tests and analyses ([Fig. 1] & 2) on vitamin D3 concentration show that this first series of tests increases vitamin D3 synthesis up to tenfold compared to the method described in document WO2019229332 AL

[0146] Increase production by 2.5 per unit area

[0147] The present invention also makes it possible to increase the production of transformed larvae per unit area.

[0148] For the record: in document WO2019229332 Al, light sources for UV treatment on live larvae are preferably positioned above the trays containing the larvae at an optimal distance of between 25 and 35 centimeters to avoid an excessive mortality rate linked in particular to excessive heat.

[0149] Thanks to the present invention, the light source can be placed between 10 and 15 centimeters without any impact on mortality.

[0150] In document WO2019229332 A1, a structure measuring 125 cm x 200 cm x 30 cm, housing the light sources and trays containing live larvae, produces 10.5 kg of live larvae, or 3.75 kg of larvae powder, over a period of 5 days, containing 24 pg / 100 g of vitamin D3 on a dry weight basis. With the present invention, the same structure, over an equivalent period, produces 9.5 kg of larvae powder containing, depending on the exposure time, between 50 and 500 pg / 100 g of vitamin D3 on a dry weight basis, i.e., 2.5 times more. This is possible by reducing the distance between the light sources and the processed larvae, but also by the fact that it is possible to work directly with processed larvae that have undergone prior heat treatment.These larvae will no longer lose weight, unlike live larvae which must undergo cooking or dehydration and will lose 65% of their total mass through water evaporation.

[0151] Reduce the light processing time by a factor of 100

[0152] According to the technique proposed in document WO2019229332 Al, 10 days of light treatment were required to achieve 50 pg / 100 g of vitamin on dry weight in the larva.

[0153] With this first series of tests, a concentration of 50 pg / 100 g on dry weight is obtained in 1 to 2 hours of UV treatment.

[0154] These results are highlighted in the second series of tests detailed below.

[0155] The analyses for quantifying vitamin D3 were carried out by a laboratory independent Cofrac certified. Quantification is performed by semi-preparative HPLC followed by reversed-phase HPLC with UV / DAD detector (265 nm).

[0156] Other tests were also carried out to highlight and optimize the advantageous effects of post-transformation UV treatment of the larvae. - 2nd series of tests: #

[0157] During this second series of tests, several samples SI, S2, S3 and S4 of Tenebrio Molitor type larvae are available. Each sample presents differences (fresh larvae, live larvae, etc.).

[0158] These analyses were carried out by an independent laboratory certified by Cofrac according to standard EN 12821: 2009-08.

[0159] During these tests, UV treatment is applied to each of these samples SI, S2, S3 and S4 and their vitamin D3 concentration is measured.

[0160] The results and analyses of these tests on samples SI to S4 are illustrated in [Fig.1]; this [Fig.1] represents more particularly the concentration of vitamin D3 for each of the samples SI, S2, S3 and S4 after 8 hours of exposure.

[0161] The first test (sample SI) relates to UV treatment on live Tenebrio Molitor larvae.

[0162] In this first test, UV treatment is planned on these live larvae as proposed in document WO2019229332 AL. The only difference is that here, the concentration of vitamin D3 is quantified directly on fresh larvae that have been previously frozen.

[0163] In this first example, the distance of the UV lamp above the live larvae is 20 cm with the following characteristics of the bulb: 25W; 10% UVB, Exo Terra; average irradiance: 74.1 pW / cm2; Average temperature: 31.8°C.

[0164] According to [Fig.1], this concentration is 3600 IU / kg on fresh weight, or about 10260 IU / kg on dry weight; this conversion to concentration on dry larvae was obtained by multiplying the concentration on fresh larvae by 2.85 (Tenebrio Molitor larvae contain on average 65% water).

[0165] Here, IU is an international unit: 1 IU = 0.025 pg of vitamin D3.

[0166] The second test (sample S2) also involves UV treatment on live larvae.

[0167] In this second test, UV treatment is therefore planned for these larvae.

[0168] Here, the distance of the lamp above the larval sample S2 is 20 cm with The following are the characteristics of the bulb: 25W, 10% UVB, Exo Terra; average irradiance: 75 pW / cm2; average temperature: 29.44 °C.

[0169] These fresh larvae are then transformed according to the technique proposed in document WO2019229332 Al to obtain a powder of dried larvae enriched in vitamin D3 by UV treatment during the larval phase.

[0170] Here we measure the concentration of vitamin D3 on dehydrated dry larvae.

[0171] According to [Fig.1], the concentration of vitamin D3 for this sample S2 is 7200 IU / kg on dry weight.

[0172] Another test (sample S3) relates to UV treatment on transformed (dead) larvae, and more particularly on dry, uncrushed larvae.

[0173] It is understood in this test that the larvae have been previously killed and that a UV treatment as proposed according to the present invention is then applied.

[0174] This test therefore corresponds to a particular implementation example of the present invention.

[0175] It should be noted that, in this example, the slaughter is carried out by immersing in a water bath at 100°C for 2 minutes. Other techniques could, however, be considered by a person skilled in the art.

[0176] In this example, the transformed larvae were dehydrated at 65°C for 14 hours.

[0177] The transformed (but not ground) larvae are then positioned under a lamp positioned at a distance of 20 cm above the dry, unground larvae; the lamp used has the following bulb characteristics: 25W, 10% UVB, Exo Terra; average irradiance: 75 pW / cm2; average temperature: 30 °C.

[0178] According to [Fig.1], the concentration of vitamin D3 for this sample S3 reaches 36,000 IU / kg on dry weight, which is five times more than the concentration of vitamin D3 for live larvae (samples S2 and SI).

[0179] The fourth test (sample S4) relates to UV treatment on transformed larvae, and more particularly to a sample of crushed dry larvae.

[0180] In this example, it is understood that Tenebrio Molitor larvae underwent the same slaughter process as the larvae in sample S3.

[0181] After felling, these were also crushed.

[0182] In this example, a UV treatment as proposed by the invention is therefore applied to this sample S4 after felling.

[0183] The same device as above is used here, namely a UV lamp positioned at a distance of 20 cm above the crushed dry larvae with the following bulb characteristics: 25W, 10% UVB, Exo Terra. Average irradiance: 75 pW / cm2. Average temperature: 30 °C.

[0184] According to [Fig.1], the concentration of vitamin D3 for this sample S4 reaches 72,000 IU / kg on fresh weight, which is ten times more than the concentration of vitamin D3 for live larvae (samples S1 and S2) and twice more than the concentration of vitamin D3 for sample S3.

[0185] This second series of tests highlights the benefit of UV treatment on transformed larvae (after slaughter) (sample S3 and S4), and not on live larvae as proposed in document WO2019229332 Al (sample SI and S2).

[0186] The Applicant submits here that, faced with UVB exposure, it could have been thought before the present invention and the above tests that the transformed beetle larvae would at best have retained a vitamin D3 synthesis capacity identical to that of the live larvae.

[0187] One might even have expected that this ability to synthesize vitamin D3 would be altered due to the transformation undergone by the larvae.

[0188] However, very surprisingly and unexpectedly, the results obtained show the opposite and highlight that exposure to UVB on transformed larvae results in more potent vitamin D3 synthesis with vitamin D3 concentrations that are five to six times higher than the concentrations obtained following UVB exposure on live larvae under similar durations and exposure conditions.

[0189] These unexpected results have a strong impact on the possible yields per unit area and therefore on the relevance of industrializing this process on transformed larvae.

[0190] This series of tests also highlights the benefit of grinding the transformed larvae before UV treatment, which further doubles the concentration of vitamin D3. - 3rd series of tests:

[0191] A third series of tests was carried out to highlight the evolution of vitamin D3 concentration as a function of UV-B exposure time.

[0192] During these tests, several samples of Tenebrio Molitor type larvae are available, noted here SI', S2', S3', S4', S5' and S6'. These samples will be subjected to different tests.

[0193] The results and analyses of these different tests on the samples are illustrated in [Fig.2]. The analyses were carried out by an independent laboratory certified by Cofrac according to standard EN 12821: 2009-08.

[0194] In this second series of tests, we have a sample SI' corresponding to degreased powder of beetles.

[0195] Here, degreased powder of Tenebrio Molitor is used, to which a UV treatment is applied via a UV lamp positioned at a distance of 20 cm above the SI' larvae. The UV lamp has the following bulb characteristics: 25W, 10% UVB, Exo Terra; average irradiance: 75 pW / cm2; average temperature: 30°C.

[0196] In this example, the oily fraction of the larvae is then extracted by pressing the dry larvae which have previously undergone blanching for 2 minutes at 100 °C and then dehydration for 12 hours at 65 °C.

[0197] According to [Fig.2], after 10 hours of exposure to UV rays, the vitamin D3 concentration of sample SI' is between 5000 and 10,000 IU / kg of vitamin D3.

[0198] In this second series of tests, sample S2' here comprises live larvae. The live larvae are then subjected to UV treatment during their growth using a lamp with the following bulb characteristics: 25W, 10% UVB, Exo Terra; average irradiance: 74.1 pW / cm²; average temperature: 31.8°C. As with sample SI in [Fig. 1], the vitamin D3 concentration analysis is performed on frozen larvae.

[0199] According to [Fig.2], the vitamin D3 concentration of sample S2' is between 150,000 and 20,000 IU / kg of vitamin D3 after a 60-hour exposure.

[0200] Sample S3' corresponds to groups of live larvae subjected to UV treatment during the growth phase. The exposure conditions are identical to those of S1' and S2'. At the same exposure time, results obtained, as shown in [Fig. 2], are substantially identical to those obtained for sample S2'. As with sample S2 in [Fig. 1], the Vitamin D3 concentration analysis is performed on dehydrated and powdered larvae.

[0201] The tests carried out on samples SI', S2' and S3' correspond to examples of implementation of document WO2019229332A1, i.e. UV treatment on live larvae.

[0202] Sample S4' corresponds to whole dried (killed) larvae. Before UV treatment, these larvae were processed by killing (boiling for 2 minutes at 100°C) and then dehydrated.

[0203] These larvae, however, remain uncrushed.

[0204] In this test, a UV treatment is then applied to this sample S4' by a lamp whose bulb has the following characteristics: 25W, 10% UVB, Exo Terra; average irradiance: 75 pW / cm2; average temperature: 29.44 °C.

[0205] Despite not grinding the slaughtered larvae, it will be noted from [Fig.2] that the concentration of vitamin D3 is high and exceeds 60,000 IU / kg of vitamin D3 after 24 hours of UV-B exposure.

[0206] Finally, in this second series of tests, we have samples S5' and S6' comprising crushed dry larvae.

[0207] Sample S5' corresponds to larvae that were cold-slaughtered at -18°C before being blanched for 2 min at 100°C, then dehydrated at 65°C for 14 hours and finally ground.

[0208] Sample S6' consists of larvae that were killed by boiling at 100 °C for 2 minutes, then dehydrated at 65 °C for 14 hours and finally ground. Each point in samples S6' comprises 2 separate analyses (N=2; Mean ± standard deviation).

[0209] For these samples S5' and S6', a UV lamp is placed at a distance of 20 cm above the live larvae. As for S4', this UV lamp has the following bulb characteristics: 25W, 10% UVB, Exo Terra; average irradiance: 75 pW / cm2; average temperature: 29.44 °C.

[0210] According to [Fig.2], the concentration of sample S5' is between 90,000 and 100,000 IU / kg of vitamin D3 after a 24-hour exposure.

[0211] According to [Fig. 2], the concentration of samples S6' is between 80,000 and 90,000 IU / kg of vitamin D3 after 24 hours of exposure. This concentration then exceeds 90,000 IU / kg of vitamin D3 after 72 hours of exposure.

[0212] This third series of tests on vitamin D3 concentration shows that the present invention makes it possible to increase, over a given exposure time, the synthesis of vitamin D3 by four to ten times compared to the method described in document WO2019229332 Al.

[0213] This third series of tests also shows that grinding maximizes the synthesis of vitamin D3, but that, on the other hand, without grinding the results obtained remain very appreciated. - 4th series of tests:

[0214] In the examples carried out above (figures 1 and 2), the average irradiance of the emitted UVB rays is 75 pW / cm2.

[0215] The experiments that will follow in the context of this 4th series of tests aim to vary the irradiance of UVB rays to highlight the influence of this irradiance on the performance of vitamin D3 synthesis.

[0216] Fig. 3 shows the evolution over time of the concentration of vitamin D3 in four samples of beetle powder, marked respectively SI”, S2”, S3”, and S4”, which are each subjected to UV treatment with light sources having different irradiances.

[0217] In this example, the samples SI” (black circles; N=2 for each duration; mean ± sd) correspond to a powder of Tenebrio molitor subjected to UV treatment by a UV source having a UVB intensity (irradiance) of 60 pW / cm2 at the level of the powder.

[0218] In this example, sample S2” (black triangle; N=2; mean ± sd) corresponds to a powder of Alphitobius diaperinus subjected to UV treatment by a UV source having a UVB intensity (irradiance) of 60 pW / cm2 at the level of the powder for 45 minutes.

[0219] The S3” samples (white circles; N=2 for each duration; mean ± sd) correspond to a powder of Tenebrio molitor subjected to UV treatment by a UV source having a UVB intensity (irradiance) of 190 pW / cm2 at the level of the powder.

[0220] The fourth sample S4” (white triangle; N=2; mean ± sd) corresponds to an &Alphitobius diaperinus powder subjected to UV treatment by a UV source having a UVB intensity (irradiance) of 190 pW / cm2 at the level of the powder for 45 minutes.

[0221] Sample S5” (grey rectangle; N=2 for each duration; mean ± sd) corresponds to a powder of Tenebrio molitor subjected to UV treatment having a UVB intensity (irradiance) of 120 pW / cm2 for 45 minutes.

[0222] In this example, the processing conditions for each of these samples SI”, S2”, S3” and S4” are identical:

[0223] Each of the UV sources is placed 25 cm vertically above the powder samples.

[0224] The average temperature in the UV treatment room is 25°C ±1 with a relative humidity of 45% ± 5.

[0225] Here, IU is an international unit: 1 IU = 0.025 pg of vitamin D3.

[0226] UVB intensity (irradiance) measurements at the sample level are measured using a UVB meter.

[0227] Vitamin D3 analyses on these samples SI”, S2”, S3”, S4” and S5” were carried out by an independent laboratory certified by Cofrac according to standard EN 12821: 2009-08 according to the reference method EN12822:2014.

[0228] On [Fig.3], it is observed that from 8 hours of UV treatment, an increase in the time of exposure to a UV source does not induce a significant increase in the concentration of vitamin D3 in the beetle powder, whether for the first SI” or the third S3” samples.

[0229] We observe in fact on this [Fig.3] a plateau in the concentration of vitamin D3 from 8 hours of exposure.

[0230] During the first experiments carried out by the Applicant, the plateau observed for the first sample appeared to correspond to the maximum achievable values.

[0231] This plateau appeared to correspond to the transformation of all the 7-dehydrocholesterols contained in the matrix exposed to UV rays into cholecalciferol.

[0232] Thus, a person skilled in the art, based on their general knowledge, could consider that the increase in vitamin D3 concentration was proportional to the increase in light intensity and that, therefore, increasing the intensity of the UVB light source would simply have allowed the vitamin D3 concentration plateau to be reached more quickly.

[0233] But this is not the case, and unexpectedly so.

[0234] Indeed, according to this same [Fig.3], we observe that by increasing the irradiance by a factor of 3:

[0235] - the maximum concentration obtained is increased by a factor of 5 for a given exposure time data (for example: a vitamin D3 level of 352,400 IU / kg for the third sample S3” of Tenebrio molitor versus a level of 70,000 IU / kg for the first sample SI” of Tenebrio molitor, for the same 8-hour exposure to UV treatment); and

[0236] - the time required to reach a concentration of 20,000 IU / kg: for example, 3.5 minutes of exposure to the third sample S3” of Tenebrio molitor is required to reach a concentration of 20,000 IU / kg of vitamin D3, compared to an exposure time of 45 minutes for the first sample SI”.

[0237] The Applicant thus observes that very high levels of vitamin D3 are reached very quickly, even with UVB exposure times of less than 10 minutes: for example, 26,000 IU / kg is reached after 5 minutes of exposure with a UV source having a UVB irradiance of 190 pW / cm2.

[0238] Comparison of the evolution over time of the concentration of vitamin D3 between the first SI” and third S3” samples (or between the second S2” and fourth S4” samples) shows that the expected proportionality relationship above between the exposure time and the irradiance of UVB rays is not found.

[0239] Therefore, the plateau in vitamin D3 concentration observed on the first sample SI” is not due to the complete transformation of sterols into cholecalciferol as suggested in the hypothesis above.

[0240] The results obtained during the present experiment thus show that by increasing the irradiance of UVB rays, the increase in the level of vitamin D3 achieves unexpected performances which are far superior to the expected results: by increasing the UVB irradiance on the transformed beetle larvae by a factor of 3, the maximum concentrations obtained are increased by a factor of 5 and the exposure time required to reach a given concentration is reduced by a factor of 10. - 5th series of tests:

[0241] Ultraviolet radiation (and in particular UVB) is known to amplify the oxidation reaction of foodstuffs. In other words, significantly increasing UVB irradiance on beetle powder (even for short periods of exposure) should a priori lead to a significant amplification of the oxidation levels of its fatty acids, potentially rendering it unfit for consumption.

[0242] In the food industry, it is therefore important not to irradiate a powder with excessively high intensities to avoid degrading the beetle powder.

[0243] The Applicant has, however, conducted tests in the present case with a view to improving the performance of its process.

[0244] In this series of tests, the Applicant thus tested the impact of a significant increase in UVB irradiance and exposure time on the oxidation of beetle powder.

[0245] During these tests, several oxidation indicators were measured, such as: - the peroxide value (PV). This value assesses the degree of oxidation of the unsaturated fatty acids in the fat. This value is an indicator of the start of oxidation. Peroxides are formed from free radicals created in the initiation phase of the oxidation reaction; - the anisidine index (AI). This index corresponds to the measurement of secondary oxidation products of fats. This index measures the quantity of aldehydes (mainly α, [3-unsaturated] aldehydes); - The TOTOX index (TOTAL OXIDATION) is a measure of oil oxidation based on the peroxide value and the anisidine value. TOTOX index = (2 x IP) + IA. A product is considered harmful if the TOTOX index is greater than 26.

[0246] By varying the irradiance and the duration of exposure, the following results are obtained at the end of these tests, which can be seen in Figures 4A to 4D:

[0247] Fig. 4A shows the peroxide indices of Tenebrio molitor powder subjected to UV exposure with UVB irradiance of 60 pW / cm2 or 190 pW / cm2 for three distinct durations: 10, 45 or 480 minutes (N=2 for each duration; mean ± sd).

[0248] It is observed that the peroxide level increases with UV exposure time.

[0249] However, for a given exposure time and under the test conditions of the present invention, the level of irradiance does not affect the peroxide level.

[0250] By increasing the UVB irradiance level by 3, the peroxide level remains similar for a given duration.

[0251] This is a rather unexpected result.

[0252] Fig. 4B shows the anisidine indices of Tenebrio molitor powder subjected to UV exposure with UVB irradiance of 60 pW / cm2 or 190 pW / cm2 for three distinct durations: 10, 45 or 480 minutes (N=2 for each duration; mean ± sd).

[0253] During these tests, it was observed that neither the duration of exposure nor the level of irradiance had any effect on this oxidation indicator.

[0254] Fig. 4C shows the TOTOX indices of Tenebrio molitor powder subjected to UV exposure with UVB irradiance of 60 pW / cm2 or 190 pW / cm2 for three distinct durations: 10, 45 or 480 minutes (N=2 for each duration; mean ± sd).

[0255] It is observed that up to 8 hours of UVB exposure, the TOTOX index values ​​are below the threshold (Dashed line on the figure; TOTOX= 26) commonly used in the food industry.

[0256] Figure 4D shows the evolution of the peroxide value of the beetle powder (Tenebrio molitor) for exposure times of 8 hours or more (N=2 for each duration; mean ± sd). It is observed that after 24 hours, the peroxide value begins to become critical. After 48 hours of exposure, the beetle powder is no longer usable because it is too oxidized, regardless of the UVB irradiance level (60 or 190 pW / cm2).

[0257] It should be noted that, in these examples, the UVB sources are placed 25 cm vertically above the powder samples. The average temperature in the UV treatment room is 25°C ±1 with a relative humidity of 45% ± 5.

[0258] The peroxide value analyses were carried out by an independent laboratory certified by Cofrac using the titration method. The anisidine value analyses were carried out by an independent laboratory certified by Cofrac using spectrophotometry.

[0259] The overall results obtained during the various experiments carried out are as unexpected as they are hoped for and allow us to consider very strong productivity gains.

[0260] The present invention makes it possible to achieve both: - a short exposure time (< 10 minutes); - very high values ​​of vitamin D3 concentration (130,000 IU / kg of powder in 10 minutes with an irradiance of 190 pW / cm2); - an oxidation level that complies with regulatory requirements.

[0261] All of these performance features allow for a reliable and profitable industrialization of the UV treatment process on the transformed beetle larvae of the present invention.

[0262] It should be noted that this detailed description relates to a particular embodiment of the present invention, but in no way does this description limit the scope of the invention; on the contrary, its purpose is to remove any possible inaccuracy or misinterpretation of the following claims.

[0263] It should also be noted that the reference signs in parentheses in the following claims are in no way intended to be limiting; these signs are solely intended to improve the intelligibility and understanding of the following claims and the scope of protection sought.

Claims

Demands

1. A process for preparing a beetle powder comprising a light treatment step during which at least one light source emits ultraviolet rays of the UVB type towards beetle larvae, said process being characterized in that the ultraviolet rays of the UVB type have an irradiance at the beetle powder greater than 80 pW / cm2 and in that said beetle larvae are dehydrated at a temperature between 40 and 250 °C, preferably between 50 and 150 °C, so that the slain larvae have: - between 2 and 15% water, more preferably between 3 and 8% water, and / or - a water activity (AW) less than 0.7 and are optionally ground before said light treatment.

2. A method according to claim 1, characterized in that the irradiance of the emitted UVB rays is between 80 and 1000 pW / cm2.

3. A method according to claim 1 or 2, characterized in that the irradiance of the emitted UVB rays is preferably between 150 and 250 pW / cm2, preferably between 170 and 200 pW / cm2.

4. A method according to any one of the preceding claims, wherein the transformed larvae have a thickness of between 1 and 100 millimeters.

5. A method according to claim 4, wherein the transformed larvae have a thickness of between 5 and 15 millimeters.

6. A method according to any one of the preceding claims, wherein the ultraviolet rays emitted by said at least one light source towards the beetle larvae during the light treatment step are: - of the UVB type and consist of electromagnetic radiation with a wavelength between 280 nm and 320 nm, and / or - of the UVA type and consist of electromagnetic radiation with a wavelength between 320 nm and 400 nm.

7. A method according to any one of the preceding claims, wherein, during the light treatment step, said at least one light source is positioned at a determined distance from the beetle larvae between 1 and 100 centimeters, preferably between 5 and 20 centimeters.

8. A method according to any one of the preceding claims, wherein, during the light treatment step, said at least one light source emits ultraviolet rays towards the transformed beetle larvae over a treatment range of between 10 seconds and 24 hours.

9. Method according to claim 8, wherein the treatment range is carried out continuously or cumulatively.

10. A method according to any one of the preceding claims, wherein, during all or part of the light treatment step, the transformed beetle larvae are maintained in an environment with a substantially constant temperature between 15 and 35°C, preferably between 22 and 26°C.

11. A method according to any one of the preceding claims, wherein, during all or part of the light treatment step, the transformed beetle larvae are maintained in an environment with substantially constant hygrometry between 20 and 80% relative humidity.

12. A method according to any one of the preceding claims, wherein the beetles are selected from the following species: Tenebrio Molitor, Alphitobius Diaperinus.

13. Beetle powder obtained by implementing the preparation process according to any one of claims 1 to 12, characterized in that it contains 130,000 IU / Kg of vitamin D3 and has an oxidation index TOTOX calculated from the peroxide index and the anisidine index TOTOX = (2 x IP) + IA of less than 26.

14. Use of a beetle powder according to claim 13 for human or animal food.

15. Use according to claim 14, wherein the powder is used as a food supplement.

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