ITVR990090A1 - INDUSTRIAL PRODUCTION OF LACTOSE SEROPROTEINS AND AN ULTRAPURADE WATER FROM CASEIFICATION SERUM - Google Patents

Description

DESCRIPTION

Title: INDUSTRIAL PRODUCTION OF SERUM PROTEINS, LACTOSE AND ULTRA-PURITY WATER FROM CASE-MAKING WHEY

The present invention relates to the realization of an industrial process for the production of organic substances and ultrapure water, obtained through a selective fractionation of the whey. The invention is based on the use of membrane separation technologies, in operating conditions such as to maximize production efficiency and minimize energy consumption and the production of by-products or processing waste. The invention provides for the use of ultrafiltration techniques in flow sequence, for the recovery of whey proteins; nanofiltration for lactose recovery; and reverse osmosis for the recovery of a concentrated saline solution and ultrapure water with a low salt content and low conductivity. The invention refers to an industrial process that treats about 60,000 liters of crude whey per day.

A) Analysis of the prior state of the art

The dairy industry and the treatment of dairy whey

The disposal of whey has been and is a significant environmental problem due to the objective difficulties of proceeding with a complete purification phase that is compatible with the costs of purification. In the recent past, each dairy farm was equipped with pig sties, built close to the milk processing centers, which absorbed whey daily as a substrate for livestock feeding. With the entry into force in May 1976 of the Merli law on the protection of water and with the problems generated by the healthiness of the dairies close to the pigsties, a period of revision of the concepts that supported these traditional systems for the use of whey began. for animal husbandry. Pig farms had to be integrated with expensive purification and manure treatment systems so many company pigsties were abandoned. The large pig farms existing in Italy today no longer operate on the basis of the residual whey of the dairies, the value of the whey is eliminated by transport costs and the market is teeming with alternative products. Today, powdered whey is used in animal husbandry for feeding fattening pigs. In other countries it is pulverized for use in animal husbandry or for use as an adjuvant in the baked goods sector, in cocoa derivatives and in the minced meat industry. However, the solutions currently adopted are certainly not in tune with the nutritional characteristics of the whey. Currently the economic value achievable on the whey market for a dairy is at most equal to the living cost of transport and pulverization. The purification treatment of dairy effluents constitutes, especially in the South, an environmental problem that is not easy to solve, which tends to worsen in the face of new environmental regulations that classify whey as a special waste or raw material based on its final use. In any case, our companies are facing a serious environmental emergency due to the technical and economic difficulties of waste disposal. All the recent community regulations, in particular the IPPC (76/61 CE) and the new law on water (152 of May 99 - Gallìi law), require production companies to formulate a detailed waste treatment plan, which is respectful of the environment and allows to increase and qualify the productivity of the company. The concern that whey will have an increase in considerable costs for the dairy sector over time, exists because the polluting power of this product is so high that no type of purifier installed could cope with the disposal of a single day of production. Whey can represent a source of noble food substances if properly treated, otherwise it will soon become the major problem of dairy centers, which on the way of disposal could force small and medium dairies to close, while on the way of valorisation it could become an economic resource. .

B) Objective of the invention

The invention is aimed at obtaining new products based on whey proteins, vitamins, mineral salts and carbohydrates, of great nutritional and commercial interest starting from whey for medium / small-sized dairies (Italian system). The invention allows to definitively and completely solve the environmental problem of whey disposal, obtaining an economic return from the recovered products (proteins, lactose, ultrapure water, mineral salts). This configures the dairy company as an "environmental company", that is, it profits from the purification of an industrial effluent. The invention allows the transformation of an inconvenient effluent such as whey, into a market opportunity deriving from the marketing of recovered products, which fully meet the commercial requirements of many semi-finished products and products for the food and pharmaceutical industry. The invention responds perfectly to the canons of the sustainable development model.

European relevance of the invention

From a commercial point of view, the dairy sector has reached a rather substantial economic level in Italy, 12,000 billion / year of turnover, while the sector dealing with the treatment of whey, in particular the marketing of derived by-products, is absolutely marginal. This industry, on the other hand, is highly developed in northern European countries such as France, Holland, Germany, Belgium, Finland, Denmark. Italy, which does not produce these materials, imports about 2,500 tons / year of whey-derived protein powders and about 7,000 tons / year of lactose. The reasons for this imbalance between whey production, estimated at about 7 million tons / year, and the strong import of derivatives, are to be found in the characteristics of our production system, consisting of small dairies spread evenly throughout the national territory and from technological delay of Italy, which is facing structural problems that European countries have already solved. The national dairy industry is going through a period of recession, due to competition from EU partners and the restrictions on milk production imposed by the E.U. The national market for dairy products, especially dairy products and cheeses, now seems to have reached the level of saturation, so that consumption growth is not foreseeable in the short term. It is necessary to focus on the production of new dairy specialties, so as to respond to the new demands of consumers, today increasingly oriented towards natural products, easily digestible, low in calories and cholesterol and above all of certified and guaranteed quality, obtainable starting from recovered products. according to the proposed process.

C) Analysis of the results achieved and related examples

Characteristics and properties of whey

Whey is the liquid that separates from milk after the cheese-making process and constitutes approximately 84-86% of the volume of processed milk. The quality of the whey, from which its economic value also derives, depends on the chemical composition and its endogenous microbial load. Sweet whey (pH 6.0-6.5) is the most interesting for the recovery of organic constituents and whey proteins in particular. It derives from the processing of grana-type cheeses, mainly seasoned, such as parmesan and pecorino. The acid whey (pH 4, 0-5,0), on the other hand, derives from the processing of fresh cheeses such as mozzarella, mascarpone and robiola or soft cheeses, such as stracchino. The acidic processing conditions generate a serum with a higher bacterial load than that of sweet whey. Sweet whey is also an unstable product, mainly due to endogenous bacterial fermentations, consisting mainly of lactic bacteria, which induce the transformation of lactose into lactic acid, with a lowering of the pH and consequent loss of commercial value. For the considerable variability of dairy production in our country, depending on the composition of the starting milk, which varies according to its own. once with the breed of the animal, the feeding conditions and the seasonal period, it is concluded that the cheesemaking whey has a different chemical composition from one dairy to another. This makes it very difficult to choose the transformation technology, which must be compatible with the chemical and microbiological composition of the whey. Only under these conditions can interesting products be recovered from whey processing.

Nature, composition and market value of the recovered products.

Processes and products of the agro-food industry are in continuous and substantial transformation to meet the new food needs of the consumer, increasingly oriented towards products capable of guaranteeing maximum authenticity with reduced caloric intake and good digestibility and which present a reduction in use of preservatives, dyes and chemical additives. The products recovered from whey, according to the proposed process, meet these requirements.

Whey proteins

In the human body, proteins perform multiple functions (structural, transporters,

regulators of biochemical reactions, etc.). The protein molecule is made up of amino acids

and whey proteins contain all the essential amino acids, that is, those that the body does

it is not able to synthesize, therefore having to take them only through food. The

whey proteins therefore have a very high biological value.

Table 1- Comparison between the biological value of some dietary proteins

(*) NET (Net Protein Utilization)

To create marketable products, alongside the nutritional properties of proteins

the so-called functional properties must be carefully weighed. In this respect, the

whey proteins have properties of great interest; in particular:

• high solubility in water;

• stability over a wide pH range (2-10);

• high hydration capacity;

• foaming properties;

• snow mountable;

• emulsifying properties;

• gel formation;

• formation of fibers.

Based on the properties mentioned and considered the vitamin content of the serum, it is possible

create a wide range of food specialties, in which the whey protein component,

vitaminic, saline and legal are essential elements of the finished product. In particular, the indicated functional properties, to which the range of possible uses of whey proteins is linked, have made it possible to identify some products such as:

• solid or liquid formulations for infant feeding (baby foods);

• diet products (low in fat, cholesterol and calories);

• hypoallergenic products;

• products for food pathologies (hospital foods);

• digestible and isotonic liquid products.

The whey proteins have very strong foaming properties, which result in stable emulsions of mixed food ingredients. This is due to the hydrophilic and hydrophobic character of the protein molecules, which allows the preparation of creams, mayonnaise and confectionery products in general. In the fractionation process of the considered whey, a protein powder at 63% with respect to the dry weight of the powder is obtained. To obtain compositions richer in proteins it is necessary to increase the volumetric concentration ratio in UF, or by applying the diafiltration technique. Diafiltration consists in adding water to the concentrated whey proteins and ultrafiltrating (diafiltrating) so that the lactose is extracted in the permeate, while the proteins are concentrated in the retentate. The operations of concentration and drying of the whey proteins could be eliminated if you want to obtain other protein formulations in solution or if you want to produce ricotta. In the latter case, the solution concentrated in UF can be directly heated to 85-90 ° C to obtain a product of particular commercial value.

Lactose

Lactose is present in whey in concentrations that vary seasonally between 4.2-5.2%. The molecule is present in two anomeric forms in equilibrium. Depending on the whey treatment process, it is possible to obtain: lα -lactose hydrate with a water molecule, by crystallization from a supersaturated solution at a temperature

below 95 ° C or β-lactose, by crystallization at a temperature above

93.5 ° C. The chemical-physical properties of lactose, which can be transformed with a process

enzymatic into glucose, are directly related to its applications in the sector

food and pharmaceutical. The main functional properties of lactose are those of

indicated below:

• increase in the sweetness of foods, in particular jams, sauces etc;

• increase in the consistency (compactness) of food preparations;

• high solubility properties in food preparations (ice cream, snacks, baked goods); • high absorption of aromatic substances or substances responsible for aromas and flavors,

• nutritional and caloric effect;

• specific fermentation;

• pharmaceutical substrate for the preparation of tablets or pharmaceutical specialties;

• emulsifying properties for bakery products;

• stabilizer of protein structures, in particular of milk casein.

Salts

Salts are a component of variable economic value depending on the final use. To

example high when used as a saline supplement for beverages, low when used for brine

cheese making.

Waterfall

The water obtained from the reverse osmosis process has a chemical composition

particularly interesting since it has a low content of mineral salts, with a

inverted NaTK + ratio compared to common mineral waters (0.38 compared to 2-4), is

in any case, free of bacterial load and other organic contaminants. At this level of

purity, it can be used both as an industrial product with a low salt content and

as water for food use (production of beverages or supplements) or as a base solution for cosmetic and / or pharmaceutical preparations. To be sterile, this water requires filtration on absolute filters (e.g. 0.4 microns) as per specific legislation.

Derivative products

The food specialties that can be obtained, starting from the whey components (whey proteins and lactose), fall within the range of “processed foods / products”. In the specialized lexicon, the aforementioned term means to indicate the class of products in which the different components (proteins, vitamins and carbohydrates) are combined in an innovative way compared to what is found in nature, in order to respond more effectively to the new needs of the consumption. Starting from pure proteins, such as whey extracted from whey, it is possible to produce foods that are balanced from an energy point of view, with a pleasant taste and the right volume.

The fractionation process

The new process involves a selective fractionation of the organic and inorganic components of the whey, using membrane technologies coupled together to obtain the maximum selectivity towards the solutes, and consequently the best production yield. The diagram shown (Table 1) summarizes the membrane treatment stages which in order are: ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (01). After the centrifugation phase which has the purpose of removing the fatty components and the fractions of casein clots present in the whey, the pasteurization is carried out, then the product is sent to fractionation with membranes. The first phase of UF involves the concentration of whey proteins (retentate), while a permeate is obtained substantially consisting of lactose, mineral salts and low molecular weight protein fractions (amino acids, peptones).

Section of UF

The process uses UF modules with a cut-off of about 10-20 Kdalton. The VCR (volume concentration ratio) represents the volumetric ratio of concentration between the volume of food and that of the concentrate, has been set in the range of 8-10. A clear yellow permeate is collected from the UF which is destined for the production of lactose powder, but which presents other interesting commercial alternatives: the beverage industry, the biochemical industry of transformations into lactic acid, glucose and galactose, lactulose, alcohol .

Section of NF

Its purpose is to concentrate lactose from 45-49 g / 1 up to about 150-190 g / 1, operating with a volumetric concentration ratio (VCR) of about 4, at an operating pressure of about 20-25 bar.

Section of OI

The NF permeate is sent to the OI section to obtain products such as ultra-pure water and a saline solution. The process is carried out at a pressure of 25-30 bar, using modules with high saline rejection; the optimal VCR is rated around 4-5. EXAMPLES

Below is a series of application examples of the invention in different operating conditions, for illustrative purposes only. All the applications were carried out starting from a food (sweet cheesemaking whey) that had the average chemical composition shown in table 2. For each of the examples, the characteristics of the products obtained are shown by varying the operating parameters relating to the three different filtration stages. in sequence (UF, NF, OI).

Tabe! 2. Average composition of sweet whey

The bacterial load reported in table 2 refers to unpasteurized whey. In the pasteurization process at 75 ° C for 15 seconds, this charge is reduced by 99.6%. Pasteurization is necessary if you want to reuse the concentrate for food purposes, in any case this process is also recommended to reduce lactic fermentations .

EXAMPLE N ° 1

Ultrafiltration stage

Volume of treated serum: 2000 liters, test duration 400 minutes. The specifications of the process are reported in table 1. 1 and in table 1.2 some data relating to the chemical composition of the products obtained from the UF stage.

Table 1.1- Process specifications Table 1.2- Analytical composition of UF of the products l F

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Nanofiltration stage

The food consists of UF permeate. Volume treated: 1800 liters, duration of the test

230 minutes.

Table 1.3- Process specifications Table 1.4- Analytical composition of NF

of products N F

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Reverse Osmosis stage

1300 liters of permeate obtained from the nanofiltration step are treated, duration of the test 175 minutes. The relative process data and the chemical composition of the products obtained from stage 01 are reported below.

Table 1.5- Process specifications Table 1.6- Analytical composition of OI of OI products

* Jp (average permeate flow);

** Pm (early pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

EXAMPLE N ° 2

Ultrafiltration stage

Volume of treated serum: 5 m3, test duration 460 minutes.

Tables 2.1 and 2.2 respectively show the data relating to the process specifications and the analytical composition of the products.

Table 2.1- Process specifications Table 2.2- Analytical composition of UF

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Nanofiltration stage

The food consists of UF permeate. Volume treated: 4.5 m3, duration 310 minutes.

Table 2.3- Process specifications Table 2.4- Analytical composition of NF

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Reverse Osmosis stage

3.2 m3 of permeate obtained from the nanofiltration step are treated, duration of the test 210 minutes.

Table 2.5- Process specifications of Table 2.6- OI analytical composition of OI products _ _

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Example N ° 3

Ultrafiltration stage

Volume of treated serum: 25m3 quintals, duration of the test 510 minutes. The process specifications and data relating to the chemical composition of the products obtained from the UF stage are reported in the tables.

Table 3.1- Process specifications Table 3.2- Analytical composition of UF of the products l F

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Nano filtration stage

The food consists of UF permeate. Volume treated: 215 quintals, duration 350 minutes.

Table 3.3- Process specifications Table 3.4- Analytical composition of NF d

and NF products

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor);

**** Vs (scrolling speed).

Reverse Osmosis stage

17 m3 of permeate obtained from the nanofiltration stage are treated, duration of the

try 450 minutes.

Table 3.5- Process specifications Table 3.6- Analytical composition of OI of OI products

* Jp (average permeate flow);

** Pm (average pressure);

*** VCR (concentration factor / ion);

**** Vs (scrolling speed).

Claims (2)

CLAIMS 1. The use of the invention in the dairy sector, in particular to recover whey proteins, lactose, mineral salts and ultrapure water from the cheese-making whey, in order to obtain a process with negligible environmental impact. 2. The use of UF, NF and 01 techniques in sequence as described in the invention in order to maximize the recovery of the whey components. 3. The use of the techniques of UF, NF and 01 in sequence as reported in Table 1, since they constitute the conditions of maximum productivity, lower energy consumption and lower consumption of reagents for the reconditioning of the membranes as well as commercial qualification of the products. 4. The chemical composition of the recovered whey proteins as reported in the tables presented, see in particular tables 1.2 and 2.2 and 3. 2. Furthermore, the protein composition can be varied by operating on the operating conditions (in particular through diafiltration) to settle at a protein percentage value from 50% to 90% (dry). 5. The coupling of the membrane technologies described in the invention with whey protein and lactose finishing processes in dried; in particular crystalline lactose through evaporation, concentration and drying of the product (up to 3% humidity) and whey protein powder, after treatment with spray drier. 6. The operating conditions of the ultrafiltration, nanofiltration and reverse osmosis plants, as reported below. 7. For Ultrafiltration: Process diagram - Feeding type: Feed and bleed in cascade, two-ramp systems in series with 12 pressure vessels of 3 modules; in this case, the necessary transmembrane pressure is obtained, for a given feed flow rate, by restricting the valves of the retentate. This system has the advantage of providing a higher productivity of the filtering system, due to a higher and more stable average flow of permeate over time. In this stage it is claimed: the geometry of the spiral module (dimensions: 4 "x 40"; 6 "x40"; 8 "x40") and the following variables: Feed rate: 2500-3000 1 / h; Permeate flow: 2100-2700 1 / h; VCR: 8-12; Temperature 17-30 ° C; Operating pressure. 3-6 bar; sliding speed 0,6-2 m / s. 8. For Nanofiltration: Process scheme - Feeding type: Feed and bleed in cascade, two-ramp systems in series with 6 pressure vessels of 3 modules. Spiraled. In this stage it is claimed: the geometry of the spiral module (dimensions: 4 "x 40", 6 "x40"; 8 "x40") and the following operating conditions: Feed rate: 3000-3500 1 / h; Permeate flow: 2200-2600 1 / h; VCR: 4-5; Temperature 17-30 DC; Operating pressure: 15-20 bar; sliding speed 2-3 m / s. 9. For Reverse Osmosis: Process scheme-Power supply type: a recirculation passage, one-ramp system with 4 pressure vessels of 2 spiral modules 4 "x 40". . At this stage, the following operating conditions are claimed: Feed rate: 2300-2500 1 / h; Permeate flow: 1700-20001 / h VCR: 4-5; Temperature 17-30 ° C; Operating pressure: 25-30 bar; sliding speed 3-4 m / s.