METHOD FOR PRODUCING A STABILIZED FOOD DRINK FROM FRUIT JUICE WITH EXTRACTS OF MICROALGAE AND / OR CYANOBACTERIA

Description

[0001] The present invention relates to the field of biomass valorization, particularly algal biomass; more specifically, the present invention relates to a process for obtaining a food beverage that can be preserved and maintains its blue color for more than 6 months, with an acidic pH, preferably based on fruit juice, comprising extracts of eukaryotic or prokaryotic microalgae (cyanobacteria), as well as the stabilized food beverage obtained by this process.

[0002] To meet the increasing global demand for food, many manufacturers are turning to alternative resources such as microalgae. These microorganisms, with their high biodiversity, represent a unique source of biomass. Their production differs from that of vegetable and cereal crops grown on arable land due to their very high yield per unit area.

[0003] Cultivated for over 30 years, microalgae are a fully-fledged food product. In human and animal nutrition, two approaches to their use exist: the first focuses on consuming the whole microalga, while the second involves the extraction, processing, and packaging of bioactive molecules derived from them. In France, only three microalgae species are authorized for unprocessed human consumption and possess exceptional nutritional properties: spirulina (Arthrospira platensis), the green microalga Chlorella, and the diatom Odontella aurita. These microorganisms are poised to become key players in the global food challenge, thanks to their unique protein content and the low environmental impact of their production: minimal water and energy consumption.

[0004] In particular, spirulina has attracted the attention of a large number of researchers and manufacturers in recent years. It is already widely available on the market in its dried, unprocessed form, for consumption as a dietary supplement.

[0005] Because spirulina contains a large number of valuable compounds, many researchers and manufacturers have focused on extracting these compounds from this cyanobacterium. The biomolecule most commonly extracted from spirulina is phycocyanin (PC), a blue pigment protein with antioxidant activity, representing 20% ​​of its dry weight (Vonshak, 1997). This growing interest in phycocyanin is largely due to its coloring power. Currently, the blue food colorings used in France are synthetic: Patent Blue V and Brilliant Blue; they are often found among the ingredients in candies and beverages. Patent Blue V has been linked to increased hyperactivity in children and may be a potential allergen, which is why it was recently banned in the United States, Canada, and Australia.Therefore, particular attention has been paid to the use of natural dyes, and in particular phycocyanin.

[0006] Water-soluble compounds extracted from microalgae and cyanobacteria, and in particular phycocyanin, present significant challenges if one wishes to incorporate them into an acidic pH beverage such as fruit juice and maintain the beverage's stability for a minimum of 6 months. By stable, we mean: Physicochemical stability of the formula, which retains its homogeneity and color over time. Stability of the formula's organoleptic characteristics, notably by preventing the growth of spoilage flora. Sanitary stability of the formula, notably by preventing the growth of flora pathogenic to humans.

[0007] The main technologies available today to beverage producers involve a heat treatment or 0.2 micrometer filtration system.

[0008] Water-soluble compounds extracted from microalgae and cyanobacteria, and in particular phycocyanin, are molecules with significant constraints: It degrades at temperatures above 45°C. It degrades at pH below 3.8. The lower the pH of the solution, the more sensitive phycocyanin is to heat.

[0009] The lower the pH of the solution, the more quickly phycocyanin clogs filters with a porosity of less than 4 micrometers.

[0010] It is therefore impossible to use a standard pasteurization or filtration process on the beverage as it currently exists in the food and beverage industry.

[0011] Documents WO2016099261, WO2013081194, WO2017050918 and US4400400 describe processes for obtaining acidic beverages containing a microalgae extract, and subjected to a pasteurization process to extend their shelf life.

[0012] Thus, the drinks currently available on the market and containing phycocyanin are not stable over a period of 12 months, with bacterial development quickly rendering them unfit for consumption, or a degradation of the phycocyanin significantly altering their color.

[0013] To increase the stability of their beverages containing phycocyanin, food manufacturers have developed processes involving the addition of preservatives and carbon dioxide. This enhances the beverage's stability but also makes it fizzy, which is unappealing to many consumers. Therefore, there is currently no process for producing a long-lasting, non-carbonated beverage containing phycocyanin with an acidic pH, particularly at room temperature.

[0014] The Holder has today developed a new process for obtaining a food beverage which can be preserved and which maintains its blue colour for more than 6 months at room temperature, preferably more than 12 months, of acidic pH, preferably based on fruit juice, comprising extracts of eukaryotic or prokaryotic microalgae (cyanobacteria), and / or purified water-soluble compounds extracted from eukaryotic or prokaryotic microalgae (cyanobacteria) such as phycocyanin, without the need for the addition of preservatives or carbon dioxide, the beverage thus obtained can therefore be flat.

[0015] Thus, a first object of the present invention relates to a process for obtaining a food beverage that is preserved and retains its blue color for more than 6 months at room temperature, preferably more than 12 months, at an acidic pH, preferably based on fruit juice, comprising phycocyanin extracted from spirulina, said process comprising at least a) a step of mixing the phycocyanin extracted from spirulina with the heat-sensitive beverage ingredients, said mixture being maintained at a pH above 7, b) an optional step of mixing the heat-insensitive beverage ingredients with the acidic pH ingredient(s), preferably fruit juice, c) a step of sterilizing the mixture obtained in step a) by microfiltration, d) a step of sterilizing the mixture obtained in step b) or the acidic pH ingredient, preferably fruit juice, by microfiltration or heat treatment, e) a step of homogenizing the sterilized mixtures obtained in steps c) and d), said sterilized mixture obtained in step c) preferably being added before the sterilized mixture obtained in step d), f) obtaining a beverage which is shelf-stable and maintains its blue color for more than 6 months at room temperature, of acidic pH, comprising phycocyanin extracted from spirulina.

[0016] Preferably, in step e), the mixture from step c) is added before the sterilized mixture obtained in step d) so as not to directly immerse the pH-sensitive mixture c) into the acidic solution d). This could cause precipitation of water-soluble compounds extracted from eukaryotic or prokaryotic microalgae (cyanobacteria).

[0017] In a particularly preferred manner, at step e), in the case where the pH of the sterilized mixture obtained in step d) is close to that of the final beverage, this sterilized mixture obtained in step d) can be added before or after the mixing in step c), because the risk of precipitation of water-soluble compounds extracted from eukaryotic or prokaryotic microalgae (cyanobacteria) no longer exists.

[0018] For the purposes of this invention, microalgae are defined as eukaryotic microalgae, which are characterized by a cell wall and a nucleus, including chlorophytes, chrysophytes and pyrrophytes, said eukaryotic microalgae being commonly referred to as "microalgae", and prokaryotic microalgae, which do not possess a nucleus and a cell wall, including cyanophytes, hereinafter specifically referred to as "cyanobacteria".

[0019] The invention uses phycocyanin from spirulina.

[0020] Water-soluble compounds, according to the present invention, are meant to designate water-soluble compounds contained in microalgae, preferably selected from proteins and peptides, water-soluble vitamins, preferably B vitamins (in particular Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic acid (B5), Pyridoxine (B6), Biotin (B8), Folate (B9), Cobalamin (B12)), minerals, preferably sodium, calcium, potassium, magnesium and iron, C-phycocyanin (or phycocyanin), and chlorophyll.

[0021] Preferably according to the invention, the water-soluble compound is phycocyanin. Long shelf life according to the present invention means a shelf life of more than 6 months, preferably more than 12 months.

[0022] Ambient temperature, according to the present invention, means a temperature of 25°C.

[0023] Acidic pH is defined as a pH below 7. Preferably the final pH of the beverage is between 3 and 5, preferably between 3.5 and 4.5, and even more preferably between 3.8 and 4.2.

[0024] Fruit juice, according to the present invention, means natural fruit juice or concentrated fruit juice, preferably reconstituted in water. The fruits may be chosen from all fruits usable for human consumption, such as orange, apple, grape, pineapple, mango, pear, peach, apricot, guava, strawberry, berries, banana, raspberry, cranberry, kiwi, preferably orange.

[0025] By heat-sensitive beverage ingredients, we mean, according to the present invention, ingredients that a person skilled in the art would know from their general knowledge to be conventionally incorporated into a food product, such as flavorings and vitamins. These ingredients, as well as extracts of eukaryotic or prokaryotic microalgae (cyanobacteria) and / or purified water-soluble compounds extracted from eukaryotic or prokaryotic microalgae (cyanobacteria), may be in powder form, to be diluted in water during the mixing step, or in a highly concentrated and stabilized liquid form.

[0026] Sterilization by microfiltration, as defined in the present invention, involves filtration carried out frontally or tangentially, advantageously using a food-grade filter, for example, a polyamide filter, particularly a nylon filter, with a particle size of less than 0.5 microns. A pre-filtration step may be performed using a filter with a particle size of 2 to 50 microns, preferably less than 25 microns. Preferably, the filtration is carried out at a constant flow rate, preferably on less than 75% of the final beverage volume, more preferably on less than 25%, even more preferably on less than 5%, and even more preferably on less than 2%.

[0027] The mixing according to the present invention is preferably carried out in mixing tanks, using an immersion blender, a mixer-beater, a homogenization tank, a pneumatic pump.

[0028] Preferably, according to the invention, the process includes an additional step of bottling the resulting beverage. Preferably, the bottling step is carried out under aseptic conditions.

[0029] Preferably according to the invention, extracts of eukaryotic or prokaryotic microalgae (cyanobacteria) and / or purified water-soluble compounds extracted from eukaryotic or prokaryotic microalgae (cyanobacteria) represent between 0.01 and 10% by weight of the beverage, preferably between 0.01 and 1% by weight of the beverage, preferably between 0.01 and 0.02% by weight of the beverage.

[0030] Preferably according to the invention, the process further comprises a step g) of preserving said beverage obtained, in the dark, for 24 hours to 7 days, preferably 48 hours.

[0031] "Darkness" refers to the preservation of the beverage obtained according to the invention in the absence of light. This dark storage improves the preservation of phycocyanin, an indicator of which is the persistence of its absorption spectrum at 620 nm. Preferably, dark storage takes place at room temperature.

[0032] Preferably according to the invention, the step of preserving said beverage in the dark allows 50%, preferably 75%, even more preferably 90% of the absorption spectrum at 620 nm of phycocyanin to be preserved 7 days after bottling (storage in the dark and at room temperature).

[0033] According to a second aspect, the invention relates to a long-life food beverage at room temperature, preferably more than 6 months, of acidic pH, preferably based on fruit juice as obtained by the process according to any one of the preceding claims containing extracts of eukaryotic or prokaryotic microalgae (cyanobacteria) and / or purified water-soluble compounds extracted from eukaryotic or prokaryotic microalgae (cyanobacteria).

[0034] Preferably according to the invention, the beverage according to the invention is still. By still is meant non-carbonated.

[0035] Preferably, according to the invention, the beverage obtained by the process according to the present invention is a stabilized beverage. A stabilized beverage, according to the present invention, is understood to be a beverage in which the microbiological levels of non-pathogenic spoilage flora remain below the target thresholds. At the end of production: < 10 CFU / ml Total mesophilic flora < 10 CFU / ml Total anaerobic flora < 10 CFU / ml Lactic acid bacteria < 10 CFU / ml Yeasts / molds At the end of the best-before date: < 200 CFU / ml Total mesophilic flora < 200 CFU / ml Total anaerobic flora < 200 CFU / ml Lactic acid bacteria < 200 CFU / ml Yeasts / molds

[0036] We will now describe, by way of non-limiting example, one embodiment of the invention EXAMPLE :

[0037] Composition of the drink: Mixture a) Ingredients Quantities per 1000 kg Reverse osmosis water QSP Spirulina extract (purified phycocyanin) 270g Magnesium 1.3kg Maltodextrin 350g Vitamin B2 100g Vitamin B12 2g Potassium sorbate 340 g Sodium benzoate 200g Mixture b) Ingredients Quantities per 1000 kg Reverse osmosis water 953 kg Concentrated orange juice 47 kg 2. Equipment 2.1 Equipment for preparing the mixture

[0038] For mixture b), based on orange juice, its preparation consisted of diluting concentrated orange juice. For this, an immersion blender was used directly in a 1 m3 tank.

[0039] For mixture a), which includes microalgae extract, the preparation requires mixing powders and dissolving the powder in water. Various equipment was used for this purpose before the 1 m³ tank: an immersion blender, a 20L mixer, a 100L homogenization tank, and a closed-circuit pneumatic pump connected to the preparation tank. 2.2 The front filtration assembly

[0040] The setup consists of a tank (1 m³) containing the mixture to be filtered, a pump, and the filter housing (with its filter cartridge). The tank is refilled during the test (by transferring the mixture from another tank using a pneumatic pump). A valve upstream of the housing can adjust the filtration flow rate (to keep it constant). The nitrogen cylinder is used during integrity tests. 2.3 The casing and filter cartridges

[0041] The housing used is a Pall sanitary FBT series housing equipped with 10" cartridges. The cartridges used are Fuente II cartridges, ref. AB1FFN7WH4: these are pleated polyethersulfone cartridges (Ultipleat® double-layer pleating) with a 0.2 µm sterilizing grade filtration threshold. They are certified for food contact. Each 10" cartridge has a filtering surface area of ​​1.04 m². 3. Method 3.1 Mixture b) = based on orange juice

[0042] To prepare mixture b), based on orange juice, 47 kg of concentrated orange juice was poured into a tank filled three-quarters full with water. The tank was then topped up with water until a mass of 1000 kg was reached. Finally, the mixture was homogenized using an immersion blender. The mixture was transferred from the preparation tank to the assembly's feed tank using a pneumatic pump. 3.2 Mixture a) = containing the microalgae extract

[0043] The first three powdered products were mixed dry in a mixer. Then, a portion of this powder mixture (400-500 g) was slowly poured into the vortex of a container holding 5-6 L of water; agitation (using an immersion blender) was maintained for approximately fifteen minutes. This concentrated mixture was then poured into a 1 m³ tank filled three-quarters full with water, and this tank was agitated again with the immersion blender. The remaining powdered products were first mixed in water (in the vortex) to a concentrated consistency, then added to the 1 m³ tank. The liquid products were added directly to the 1 m³ tank. After adding all the products, the 1 m³ tank was homogenized with the immersion blender and also by closed-loop circulation using a pump. 3.3. Sterilization of mixtures by microfiltration

[0044] Each mixture a) then b) is microfiltered (a new cartridge is used for each mixture) with the following results: Mixture b) Mixture a) Pressure (bar) 2 2,46 Filtration rate (kg / h / m2) 769 (constant) 770 Filtered mass (kg / m3) 1920 790 Filtrate PH 4 pH 8.6, turbidity 36 NTU, absorbance (620 nm): 0.388 3.4: Homogenization of mixtures a) and b)

[0045] The mixtures a) and b) sterilized in step 3.3 are mixed and homogenized in a 2m2 tank using an inclined paddle stirring system.

[0046] Mixture a) is added first to the homogenization tank

Claims

1. Process for obtaining a food drink which keeps well and which maintains its blue color for more than 6 months at ambient temperature, has an acid pH, is preferably based on fruit juice, and comprises phycocyanin extracted from spirulina, characterized in that said process comprises at least a. a step of mixing the phycocyanin extracted from spirulina with the ingredients of the drink that are sensitive to heat treatments, said mixture being maintained at a pH above 7, b. an optional step of mixing the ingredients of the drink that are insensitive to heat treatment with the ingredient(s) having an acid pH, preferably the fruit juice, c. a step of sterilizing the mixture obtained in step a) by means of microfiltration, d. a step of sterilizing the mixture obtained in step b) or the ingredient having an acid pH, preferably the fruit juice, by means of microfiltration or heat treatment, e. a step of homogenizing the sterilized mixtures obtained in steps c) and d), said sterilized mixture obtained in step c) preferably being added before the sterilized mixture obtained in step d), f. obtaining a drink which keeps well and which maintains its blue color for more than 6 months at ambient temperature, has an acid pH, and comprises phycocyanin extracted from spirulina.

2. Process according to the preceding claim, characterized in that the drink is based on fruit juice, the acidic ingredient being natural or concentrated fruit juice.

3. Process according to any of the preceding claims, characterized in that it comprises an additional step of bottling the obtained drink under aseptic conditions.

4. Process according to any of the preceding claims, characterized in that the phycocyanin extracted from spirulina represents between 0.01 and 1 wt.% of the drink, preferably between 0.01 and 0.5 wt.% of the drink, preferably between 0.01 and 0.02 wt.% of the drink.

5. Process according to any of the preceding claims, characterized in that it additionally comprises a step g) of storing said obtained drink, in darkness, for 24 hours to 7 days.