Patent Application
20200308311
The invention relates to the production of heat-modified starch, and to the starch whose viscosity is stabilized following this heat treatment. Such heat-modified starches then find use as texturing agents and thickeners in numerous food applications, notably in soups and sauces, in desserts such as yogurts, stirred fermented milks, thermized yogurts and dessert creams, but also drinks, ready meals, or meat- or fish-based preparations, such as surimi.
Synthesized biochemically, starch, which is a source of carbohydrates, is one of the most widespread organic materials of the plant world, where it constitutes the nutritional store of organisms.
For a long time, starches have been used in the food industry, not only as a nutritive ingredient, but also for their technological properties, as thickener, binder, stabilizer or gelling agent.
For example, native starches are used in preparations which require cooking. Corn starch, in particular, is the basis of “flan powders”.
As it is rich in amylose, it retrogrades and thus gels strongly. It allows the production of set flans after cooking and cooling.
It is also suitable for custard cream mixes.
However, said starches cannot be included in pastries intended to be frozen, since, on thawing, the phenomenon of syneresis, which is reflected by an expulsion of water, destroys the texture of the cream.
Thus, in native form, starch is of limited application on account of the syneresis, but also on account of:
As a result, to meet the current demanding technological needs, the properties of starch must be optimized via various methods known as “modification”.
These main modifications are then directed toward adapting starch to the technological constraints resulting from cooking, but also from freezing/thawing, canning or sterilization, and toward making it compatible with modern nutrition (microwaves, ready meals, “high temperatures”, etc.).
The modification of starch is then directed toward correcting one or more of the defects mentioned above, thus improving its versatility and satisfying consumer demand.
Starch modification techniques have been globally classified into four categories: physical, chemical, enzymatic and genetic, the final purpose being to produce various derivatives with optimized physicochemical properties.
Chemical and physical modifications are the ones most often performed.
Chemical treatment consists in introducing functional groups into starch, which considerably alters its physicochemical properties. Such modifications of granular native starches indeed have a profound effect on the gelatinization, bonding and retrogradation behavior.
Generally, these modifications are achieved by chemical derivatization, such as esterification, etherification, crosslinking or grafting.
However, chemical modifications are less desired by consumers in food applications (also for environmental reasons), even though certain modifications are considered as safe.
Various physical modifications are consequently proposed, for example:
An alternative form of “thermal inhibition” treatment was proposed in solvent phase, which consists in heating a non-pregelatinized granular starch in alcoholic medium, in the presence of a base and salts, at a temperature of 120° C. to 200° C., for 5 minutes to 2 hours.
In any case, the thermal inhibition process then leads to the production of a starch paste which has increased viscosity breaking resistance properties, and a noncohesive texture.
The technical field to which the invention applies is that of the thermal inhibition treatment of starch, without aqueous-alcoholic solvent.
In this particular technical field, mention may be made more particularly of U.S. 6,221,420, which describes a thermally inhibited starch, obtained by dehydration followed by heat treatment.
The main steps are:
Preferentially, before the starch dehydration step, it is recommended to perform a step of basification of the starch, bringing the pH of the starch suspension to a value of between 7 and 10, preferably between 8 and 10.
At this stage, before the actual dehydration step which precedes the inhibition step, the water content of the starch (as illustrated) is then between 8% and 10%.
US 2001/0017133 describes a similar process, in which starch is also dehydrated below 125° C. before commencing the inhibition process (at a temperature above 100° C., preferentially between 120 and 180° C., more preferentially between 140 and 160° C.) fora time of up to 20 hours, preferentially between 3 hours 30 minutes and 4 hours 30 minutes.
Before the dehydration step, the conventional basification step leads to a starch suspension with a pH value of between 7.5 and 11.2, preferably between 8 and 9.5, and a water content of between 2% and 15%.
One variant was proposed in patent application WO 2014/042537, this variant relating to heating of an alkaline starch to temperatures of between 140 and 190° C., taking care to ensure that the inhibition process is started and conducted in the presence of a sufficient amount of water, i.e. more than 1% of water.
In other words, this process recommends thermally inhibiting a pre-basified starch without performing a dehydration step.
The starch preparation or the starch is thus brought to a pH of between 9.1 and 11.2, preferentially to a value of about 10, and the moisture is adjusted to between 2% and 22%, preferentially between 5% and 10%.
The thermal inhibition is then performed directly on this powder or this starch, at a temperature of between 140 and 190° C., preferentially between 140 and 180° C., for a time of 30 minutes.
From all of the foregoing, it is observed that the thermal inhibition processes used for stabilizing the viscosity of starches involve processes requiring
The need thus remains for a novel process for the inhibition of starch, making it possible to further reduce the reaction time, and without it being necessary to control the water content of the starch to be “thermally inhibited”.
Thus, the invention relates to a process for producing a heat-modified starch from a starch milk, comprising the steps consisting in:
The starch to be used in the process of the invention may be of any origin, for example corn, waxy corn, amylomaize, wheat, waxy wheat, pea, potato, waxy potato, tapioca, waxy tapioca, rice, konjac, etc.
Preferentially, corn starch will be chosen, more particularly waxy corn starch (with a high content of amylopectin), potato starch, cassava starch and pea starch, as will be illustrated hereinbelow.
The alkaline agent is preferentially chosen from the group consisting of sodium hydroxide, sodium carbonate, tetrasodium pyrophosphate, ammonium orthophosphate, disodium orthophosphate, trisodium phosphate, calcium carbonate, calcium hydroxide, potassium carbonate and potassium hydroxide, taken alone or in combination, even more preferentially sodium carbonate.
The process in accordance with the invention first requires the preparation of a starch milk with a solids content of between 30% and 40%, preferably between 35% and 37% by weight. As will be illustrated hereinbelow, the solids content is set at 36.5% by weight.
The next step then consists in controlling the alkaline impregnation of the starch by adding the alkaline agent in powder form to obtain a final conductivity, on the powder resuspended to a solids content of 20%, of between 0.7 and 2.5 mS/cm.
A contact time of between 0.5 and 5 hours is then ensured.
Specifically, the Applicant Company has found that:
Moreover, since impregnation in a powder phase requires adjustment of the moisture of the starch to high values, part of the energy dedicated to the treatment of the product will thus be lost to ensure the evaporation of the residual water.
The final step consists in heating the dry starch thus obtained so as to bring it to a temperature above 180° C. for a residence time of between 8 and 50 minutes, preferably between 10 and 40 minutes, even more preferentially between 12 and 35 minutes.
The Applicant Company has noted that the duration of the residence time could be adjusted as a function of the nature of the chosen starch.
Thus, as will notably be illustrated hereinbelow, the treatment of waxy corn starch requires residence times of from 15 minutes to 20 minutes, or up to 30 or even 35 minutes, whereas the treatment of pea starch takes only 10 to 25 minutes.
This treatment will advantageously be performed, as will be illustrated hereinbelow, in heat treatment devices combining heat exchanges by conduction and by convection, a device of turbo dryer type, for example at least one VOMM continuous turbo dryer, which thus makes it possible, as a function of the size of said VOMM machine, to achieve a very short reaction time, of the order of a few minutes, i.e. less than 5 minutes per heat treatment stage.
The nominal temperatures are then set at values of more than 190° C., preferably between 195 and 240° C., and the delta T, defined as the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, is between 15 and 25° C.
The heat-modified starches according to the invention will advantageously be used, as a function of their respective properties, as thickener or texturing agent in food applications, notably in soups, sauces, drinks and ready meals and in desserts such as yogurts and stirred fermented milks and “thermized” yogurts.
By virtue of their texturing and gelling properties, they will also find numerous applications in fields as varied as:
The invention will be understood more clearly with the aid of the following examples which are intended to be illustrative and nonlimiting.
The method used herein is adapted from the European Pharmacopea—official edition in force—Conductivity (§ 2.2.38).
Knick 703 electronic conductimeter also equipped with its measuring cell and checked according to the procedure described in the related instruction manual.
A solution containing 20 g of sample and 80 g of distilled water, having a resistivity of greater than 500 000 ohms·cm, is prepared.
The measurement is taken, at 20° C., using the conductimeter with reference to the procedure indicated in the machine's operating manual.
The values are expressed in microSiemens/cm (μS/cm).
Measurement of the Viscosity of a Starch Suspension using the Rapid Viscometer Analyzer (RVA)
This measurement is performed at acidic pH (between 2.5 and 3.5) under given concentration conditions and following a suitable temperature/time analysis profile.
Two buffer solutions are prepared:
The following are added to a 1 liter beaker containing 500 ml of demineralized water:
The contents are transferred into a 1 L graduated measuring cylinder and made up to 1 L with demineralized water.
100 g of Buffer A are mixed with 334.0 g of demineralized water.
The product to be analyzed is prepared in the following way:
A mass of 1.37 g of the dry product to be analyzed thus obtained is introduced directly into the viscometer bowl, and the solution of Buffer B is introduced until a mass equal to 28.00±0.01 g is obtained. The mixture is homogenized with the stirring blade of the Rapid Visco Analyzer (RVA-NewPort Scientific).
The time/temperature and speed analysis profile in the RVA is then produced as follows:
End of test: 00:20:05 (hh:mm:ss)
Initial temperature: 50° C.±0.5° C.
Data acquisition interval: 2 seconds
Sensitivity: low
The results of the measurements are given in RVU (unit used for expressing the viscosity obtained on the RVA), given that 1 RVU unit=12 cPoises (cP).
As a reminder, 1 cP=1 mPa·s.
The results will thus be presented in mPa·s.
The measurements will be of the viscosity taken “at the peak”, i.e. maximum viscosity value between 4 and 6 minutes, and “on dropping”, i.e. the difference between the viscosity at the peak and that measured at 17 minutes.
1) The basification of waxy corn starch is performed according to the following steps:
2) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 200° C. and which are configured to subject the product to a residence time of 20 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 16 to 17° C.
The RVA viscosity measurements are performed and are presented in the table below.
1) The basification of waxy corn starch is performed according to the following steps:
2) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 210° C. and which are configured to subject the product to a residence time of between 15 and 20 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 21 to 23° C.
The RVA viscosity measurements are performed and are presented in the table below.
3) The basification of waxy corn starch is performed according to the following steps:
4) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 210° C. and which are configured to subject the product to a residence time of between 25 and 30 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 22° C.
The RVA viscosity measurements are performed and are presented in the table below.
The basification of waxy corn starch is performed according to the following steps:
5) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 210° C. and which are configured to subject the product to a residence time of 35 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 22° C.
The RVA viscosity measurements are performed and are presented in the table below.
In conclusion for these first four examples:
Each family of starches heat-modified according to the invention has improved stability during the process of use relative to the native starch: less gain in viscosity and less retrogradation are observed during the use of these starches.
Regarding this last point, it is in point of fact observed that the more the RVA drop tends toward 0 or becomes negative, the more the product will be functionalized and the less it will express retrogradation.
The heat-modified starches of family “D” represent the products that have the greatest resistance to shear, to the acidity of the media and to the heat treatments.
The heat-modified starches of family “C” are slightly less resistant than the heat-modified starches of family “D”, the heat-modified starches of family “B” are slightly less resistant than the heat-modified starches of family “C” and the heat-modified starches of family “A” are less resistant than the heat-modified starches of family “B”.
The choice of the use of these starches will thus be made as a function of the intended application and thus of the shear, acidity and temperature conditions used, as will be demonstrated hereinbelow in the implementational examples.
An analysis is performed comparing the products according to the invention with commercial products of the same category, according to the following protocol:
Dependent on the other process parameters such as the Delta T and the dose of carbonate.
For a 1.5 kg batch:
At the end, the recipe is characterized by:
The level of cooking is determined by light microscopy (Leica microscope—×20 lens and ×150 amplification). The sample is dispersed in demineralized water and then colored with Lugol for the purpose of revealing the starch granules. The iodine reacts with the amylose and forms spiral-structured complexes. A blue/violet color results if the starch is rich in amylose. Otherwise, the color of the starch granules remains brown/yellow.
The light microscopy observations give various information:
The sensory characterizations are subjective assessments and the comments in terms of visual aspect and texture (by spoon and/or in the mouth) were made by a panel of five trained people. They make it possible above all here to assess the qualities of the manufactured products and are produced here for purely illustrative purposes.
The measurements are taken on a Brookfield DV1 rotational rheometer.
In general, the rheology of food products is characterized by non-Newtonian behavior: the viscosity changes as a function of the applied level of shear.
The Brookfield viscometer is used here at three rotational speeds to confirm (or otherwise) this behavior.
Conditions of use:
Repeatability: average of three measurements. Accuracy: 5%
4.a. Flow Measurement
Equipment: Anton Paar, MCR301 rheometer
Characterization of the behavior of non-Newtonian fluids. The instrument imposes a specific stress field or a strain on the fluid, and monitors the resulting strain or stress.
The results are expressed in a logarithmic-scale curve of viscosity (Pa·s) as a function of the shear rate (γ).
The noteworthy results are the viscosity at γ=10 s−1 (equivalent shear of the texture measured by spoon) and γ=40 s−1 (equivalent shear of the texture measured in the mouth).
The yield point represents the minimum stress applied to place a product or a material in motion.
It is calculated with the Herschel Bulkley modeling, using the curve of stress as a function of the shear (resulting from the flow curve).
Analysis: Oscillation
Repeatability: average of three measurements
Accuracy: 5%
4.b. Viscoelastic Behavior G′/G″
Equipment: TA Instruments, DHR-2 rheometer
Characterization of the behavior of non-Newtonian fluids. The instrument imposes a specific stress field or a strain on the fluid, and monitors the resulting strain or stress.
The results are expressed in a table with a modulus of elasticity (G′) which characterizes the solid part and the viscous modulus (G″) which characterizes the liquid part.
The general interpretations of the analysis of the food products are “liquid-type behavior” if (G′<G″) or “solid-type behavior” if (G′>G″).
Geometry: Concentric Cylinders
Analysis: Oscillation
Repeatability: average of three measurements
Accuracy: 5%
The microscope allows a qualitative analysis of the level of cooking of the starch grains.
In general, no significant difference is observed between the level of cooking on exiting the Hotmix and after passage through the autoclave. The autoclave pasteurization step is thus considered a “sanitization” step rather than an additional cooking step.
The microscopic observations of the two starches CLARIA®+and NOVATION® 2300 show starch grains that are well cooked.
The microscopic observation of CLEARAM® CH2020 shows starch grains that are well cooked, and also a certain amount of debris.
The microscopic observation of the heat-modified starch “D” according to the invention shows starch grains that are well cooked and a few raw grains.
For this product, compared with the others, less debris and slightly inferior cooking are observed. It is the most resistant of the products tested.
The samples were evaluated by spoon and classified from the thickest (the most viscous) to the most fluid (least viscous).
There is no significant difference, which indicates that the heat-modified starch according to the invention is an alternative to the products conventionally proposed for giving native starches properties of chemically modified starches.
The graph of
The overall shear-thinning behavior is confirmed: the higher the shear, the less viscous the product. For certain samples, at a speed of 10 and 20 rpm, the viscosity reaches the measurement limits (full scale).
The classification of the products (from the thickest to the most fluid), in the table below, is with tests measured at 5 rpm.
Considering the entire viscosity range obtained with the various thermally inhibited starch tests (from 11 260 to 21 770 mPa-1), the heat-modified starch “D” according to the invention represents the most fluid product and NOVATION® 2300 represents the thickest product.
4.a. Flow
The yield point represents the minimum stress applied to place a product or a material in motion.
It is calculated with the Herschel Bulkley modeling, using the curve of stress as a function of the shear (resulting from the flow curve)—cf.
The yield points calculated from the ketchup tests are represented in the table below, classified from the thickest to the most fluid.
The behavior of the heat-modified starch “D” according to the invention is equivalent to that of NOVATION® 2300.
On the graph of the flow results, used to determine the yield point, it is chosen to consider the viscosity at a shear rate of 10 s−1 (shear representative of that applied by spoon).
The results are presented in the graph of
The heat-modified starch “D” has a medium viscosity value.
4.b. Viscoelastic Behavior G′/G″
For all the ketchup tests, G′ is dominant, which is proof that the ketchup has “solid-type behavior”.
However, they show a different viscoelastic behavior.
Results in line with the preceding results.
The heat-modified starch “D” according to the invention has, in the ketchup sauce application, behavior equivalent to that of the chemically modified waxy starch control, and to that of the thermally inhibited starch NOVATION® 2300.
Conventional stirred yogurt (or fermented milk) recipe, containing starch for a creamier texture.
The designation “yogurt” or “fermented milk” does not allow the incorporation of starch in certain countries, and in this case this product will be referred to as a fermented dairy specialty.
The tested products are (according to the names of the preceding examples):
A few differences are observed between the fermentation times. They are more linked to the repeatability of the tests under laboratory conditions than to the starches themselves.
The state of cooking of the starch is monitored with a light microscope (as in example 6) in the various steps of the process:
To better visualize the starches, the Lugol dye is used, which stains the granules blue in the case of presence of amylose, and brown in the case of presence of amylopectin only.
The state of cooking of the starches, before homogenization (60° C.) (polarized light), does not show any significant difference.
Some starches already began to swell at 60° C. before homogenization. This is explained by the differences in swelling temperatures intrinsic to each starch.
After pasteurization, the state of cooking depends on the starch used. It should be noted that the batch corresponding to the heat-modified starch “D” according to the invention confirms the result explained in example 6. The presence of numerous raw granules indicates better resistance of these products to the heat treatment.
It should be noted that no granule fragments are observed, in any of the photographs. This means that all the granules of the various batches were not destroyed by the heat treatment or shearing.
The viscosity is measured after 1 day, 7 days, 15 days and 21 days.
The values are given with an uncertainty of ±5%.
It is observed that, after 1 day, the least viscous tests are those based on NOVATION® 2300 and on CLEARAM® CJ5025.
However, the viscosity differences remain small, and are not constant on storage.
The panel consisted of 29 people among the Roquette staff. During the tasting of the products, 11 and then 13 people participated in the two different sessions.
The panel is qualified for tasting formulated products. The group was trained to check its performance in terms of:
The sensory analysis takes place in a dedicated laboratory, with individual cubicles, a calm, odor-free environment (to aid concentration) and white lighting.
The tasting is performed blind with a three-figure code, and the products are presented in a random order, to avoid persistence effects.
Moreover, the tasting of the tests was performed in two series, to avoid saturation during the session:
The analysis of the results is performed by multiple-factor analysis (J. Pagès, 1994), and shows that:
The three descriptors “glossy”, “milky taste” and “astringent” are not discriminating on this series of products.
The yogurts formulated with the heat-modified starches “C-1” and “C-2” are similar, they are creamier, sweeter, more fatty and more granular than the other products. The heat-modified starch “C-1”, however, gives a product that is more fondant, less acidic and less thick than the heat-modified starch “C-2”.
The heat-modified starch “D” is as unacidic as the heat-modified starch “C-1”.
The five descriptors “glossy”, “sweet”, “fondant”, “milky taste” and “astringent” are not discriminating on this series.
However, the panel members established the following differences:
The conclusions of this study are that all the starches tested appear to have withstood the process used here, since no starch fragments were observed.
The starches according to the invention have, for some of them, characteristics similar to those of the already-existing product: thus, the heat-modified starch “D” differs only in a slightly higher acidity of the yogurt.
Similarly, the heat-modified starch “C-1” leads to products that are similar to the existing product.
The heat-modified starch “C-2” even makes it possible to achieve levels of creaminess perceived to be superior. It could thus be used at a lower dose for the same result.
The Base Recipe used is as Follows:
1. Preparation of the premixes:
3. Add the premix (Water & other liquid ingredients)
4. Place at speed 3 for 1 minute
5. Add the powder premix (at speed 3 for 1 minute)
6. Precook (speed 3/10 minutes/80° C.)
7. The optional treatments are as follows:
The internal control system of the Steriflow machine (MPI Expert) is used to manage the process cycles.
By means of the temperature probes placed at the center of the product (coldest point), the machine records the useful data during the cycle for the purposes of the study:
F
0
=ΔT*10(T−121/Z)
Equipment: Konica Minolta, CM-5 spectrophotometer
Color analysis method: L* a* b* colorimetric space/ΔE: CIE 2000
Sample: 6 g of powder, wrapped, in a Petri dish (Konica Minolta ref. 1870-712, glass, diameter 40 mm)
Measurement zone: ∅30 mm, with ∅35 mm sighting mask
Type of measurement: reflectance; method: Petri dish
Observer: 10°/D65
Repeatability: 0.004
The lightness, L*, represents the darkest black at L*=0, and the brightest white at L*=100.
The color channels, a* and b*, represent the true values of neutral grays at a*=0 and b*=0.
The color difference ΔE (delta E) is calculated between the color of a chosen sample L1a1b1 and the reference color L2a2b2.
The result is calculated by means of the online calculator www.brucelindbloom.com (“calc”/“Color Difference Calculator” section), where the “CIE 2000” result is used.
The smaller the ΔE value, the more similar the color of the two products.
If ΔE is >1.5, the color difference is considered to be perceptible to the human eye.
The sensory characterizations are subjective assessments and comments in terms of visual aspect and texture (by spoon and/or in the mouth).
Depending on the resistance of the starch to the process (freezing and/or heat treatment), a certain amount of syneresis (release of water) may take place. The product is screened (fine mesh) for 6 minutes, the amount of phases is weighed and the result is given as a percentage.
After screening and weighing the syneresis, the two phases (syneresis water and remaining sauce) of the sample are returned into a tank.
The sensory nature is evaluated primarily on the remaining sauce phase (the sauce may be more concentrated or thicker).
The level of cooking is determined by microscopy, as in the above example 5.
Characterization of the behavior of non-Newtonian fluids: the instrument imposes a specific stress field or a strain on the fluid, and monitors the resulting strain or stress.
Geometry: CC27 concentric cylinders
Analytical conditions: All the samples were analyzed for the rheology 1 day after the production date, after stabilization at 20° C.
Repeatability of all the analyses: mean of three measurements
Accuracy: 5%
The results are expressed by a logarithmic-scale curve giving the viscosity (Pa·s) as a function of the shear rate (γ).
The noteworthy results are the viscosity at:
The yield point represents the minimum stress applied to place a product or a material in motion. The lower the result, the lower will be the effort required to place it in motion.
It is calculated with the Herschel Bulkley modeling, using the curve of stress as a function of the shear (resulting from the flow curve).
The results of the viscoelastic behavior (G′/G″) are expressed in a table with a modulus of elasticity (G′) which characterizes the solid part and the viscous modulus (G″) which characterizes the liquid part.
The general interpretations of the analysis of the food products are “liquid-type behavior” if (G′<G″) or “solid-type behavior” if (G′>G″).
These results reflect:
Furthermore, the heat-modified starch “D” according to the invention has behavior equivalent to that of a conventional thermally inhibited starch.
The color difference ΔE (delta E) is calculated between the color of a chosen sample L1a1b1 and the reference color L2a2b2.
It was calculated at four different viewpoints in order to have the fullest comparison:
The results are shown in
It should be noted that the smaller the value of ΔE, the more similar the colors of the two products. If the ΔE>1.5, the color difference is considered to be perceptible to the human eye.
Only the ΔE results of the repeatability study for CLEARAM® CH2020 (ΔE (repro CH20)) are less than 1.5.
All the other ΔE results are very discriminating:
As a reminder, the products underwent the three different treatment options, and were observed on day +1 at 20° C.
The pasteurized sample will be taken as reference since it is considered to be the closest to the intended target for this type of matrix in terms of visual aspect and texture.
All the frozen and thawed samples present syneresis, and also a granular, micro-gelled texture, etc.
The heat-modified starch “D” has, compared with the other two products:
All the sterilized products have a more fluid texture and a heterogeneous darker red color (associated with a more pronounced Maillard reaction).
The histograms presented in the following figures show the means of the results for each test, under three parameters: viscosity as a function of the stress, yield point and viscoelastic nature.
The results show good repeatability of the results of the three repetitions for each sample.
The histogram is a complete and simplified view (mean of three repetitions). Each bar represents a noteworthy viscosity result (5; 10; 100; 350 s−1).
All the samples, for the two heat treatments, have shear-thinning behavior (the viscosity decreases as the shear rate increases).
The sterilized samples (S) are more fluid than their pasteurized samples (P). The heat treatment has an influence on the rheological behavior, irrespective of the starch.
For the pasteurized and sterilized samples, NOVATION® 2300 presents results inferior to those of the reference CLEARAM® CH2020.
The heat-modified starch “D” has a lower viscosity than that of NOVATION® 2300, except under the sterilization conditions where the heat-modified starch “D” appears to be slightly thicker.
The group classification shows that the heat-modified starch “D” and NOVATION® 2300 have similar performance qualities under the pasteurization conditions.
As for the preceding analytical results (viscosity as a function of the stress), there is a similar profile in the classification of the products:
The sterilized samples (S) have a yield point that is slightly lower than that of the pasteurized samples (P). The heat treatment has an influence on the rheological behavior: reduced resistance of the starch to this high heat treatment.
For the pasteurized samples, NOVATION® 2300 presents moderate results, between the CLEARAM® CH2020 reference prototypes and the heat-modified starch “D”.
The heat-modified starch “D” appears to be the most efficient and the closest to the reference products (CLEARAM® CH2020 and NOVATION® 2300).
For each test, G′ is dominant relative to G″, which is proof that the product has “solid-type behavior”.
The histogram focuses only on the value G′.
As for the flow analytical results, there is a similar profile in the classification of the products:
The sterilized samples (S) have lower cohesion than their pasteurized samples (P). The heat treatment has an influence on the rheological behavior, by damaging the starch. Globally, all the heat-treated starches are less resistant to the sterilization treatment.
For the pasteurized samples, NOVATION® 2300 shows cohesion that is quite close to that of CLEARAM® CH2020.
The heat-treated starch “D” appears to be coherent.
For the sterilized samples, NOVATION® 2300 shows cohesion that is closer to that of the heat-treated starch “D”.
The conditions of the sterilization process defined for this study appear to be a discriminating parameter.
This treatment option makes it possible to go further in the discrimination of the clean starches between each other and in comparison with CLEARAM® CH2020 and NOVATION® 2300.
The heat-treated starch “D” is classified in the category of thermally modified reference products, like NOVATION® 2300.
The heat-modified starches obtained by means of the process according to the invention were tested in thermized yogurts, also known as ambient yogurts or extended shelf life yogurts.
These yogurts are subjected to a heat treatment after fermentation, which makes it possible to conserve them at room temperature for several months.
The various starches tested are as follows:
The starches are tested in a strawberry-flavored drinking yogurt, containing fruit concentrate.
There is no impact of the starch on the fermentation time. The three products reach the desired pH in an equivalent time.
Before addition of the strawberry purée, the products have a slightly beige white color.
The state of cooking of the starch is monitored with a light microscope in the various steps of the process
The preparation is colored with Lugol to improve the visualization of the starches.
After pasteurization, the starch granules are, on the whole, satisfactorily swollen. The least swollen is the modified starch (CLEARAM® CJ5025). No fragments are observed.
Satisfactorily swollen granules are observed in the three products. No starch fragments are visualized. The starches satisfactorily withstood the heat treatments.
The NOVATION® 2300 granules appear on average slightly less swollen than those of the heat-modified starch C.
The viscosity is measured after 1 day, 7 days, 15 days and 30 days. The values are given with an uncertainty of ±5%.
The two tests containing starch without chemical modification have similar viscosities.
On the other hand, the test with CLEARAM® CJ5025 is less viscous at all the storage times.
The change in the viscosities shows that there is no retrogradation of the starch in the yogurts since an increase in viscosity would then be observed on storage.
The water-holding capacity of the yogurts is analyzed by performing the following test, adapted from a method of Harte and Barbosa-Canovas:
It is found that the water-holding capacity of the starch according to the invention is close to that obtained with the modified starch.
It is moreover stable on storage, which confirms the absence of syneresis. However, the competing starch retains slightly less water.
The three products were evaluated by expert dairy product tasters. The comments collected are as follows:
This tasting makes it possible to confirm that the starchs used do not introduce any foreign taste into the yogurt.
On the other hand, they are distinguished as regards the perceived acidity, NOVATION® 2300 being the one which affords the most acidity.
The heat-modified starch “C” makes it possible to obtain a yogurt of more outstanding taste quality.
In summary, the heat-modified starch according to the invention thus has performance at least equivalent to that of the modified or unmodified starch conventionally used in this application, and proves to be organoleptically more acceptable than NOVATION® 2300.
The heat-modified starches obtained with the process according to the invention were tested in mayonnaises prepared via a hot process, these mayonnaises having a low fat content (25-35% fat).
Suitable for amounts of from 800 g to 2 kg, a batch of 1 kg of low-fat mayonnaise is prepared here.
Use of the 2 L Hotmix Pro Creative mixer (speed 1E=480 rpm; speed 3: 800 rpm; speed 4: 1800 rpm; speed 5: 3000 rpm; speed 6: 4000 rpm).
Phase A: cook the starch milk in the bowl of the Hotmix machine (speed 1E, 90° C., 10 minutes). Leave to cool to 50° C.
Phase B: prepare the liquid ingredients (starch paste and mustard) in the bowl of the Hotmix machine. Prepare the powders in a separate vessel.
Disperse thoroughly and homogenize this powder mix.
Prepare phases C and D in separate vessels.
Add the powder mixture to the Hotmix bowl in which the starch milk is maintained at 50° C., and mix at speed 3 for 1 minute.
Add Phase C and then Phase D portionwise via the top of the vessel.
Change the speed from 4 to 6, depending on the consistency of the product, without exceeding a mixing time of 3 minutes.
Continue mixing at speed 6 for 1 minute.
The sensory characterizations are subjective assessments and comments in terms of visual aspect and texture (by spoon and/or in the mouth).
Equipment: Konica Minolta, CM-5 spectrophotometer
Color analysis method: L* a* b* and L* C* h° colorimetric space/ΔE: CIE 2000
Sample: 20 g, in a disposable Petri dish (VWR, “round PS Petri dish without lugs”, plastic, 55 mm diameter)
Measurement zone: ∅ 30 mm, with ∅ 35 mm sighting mask
Type of measurement: reflectance; specular component excluded (SCE)
Observer: 10°/Illuminant: D65
The lightness, L*, represents the darkest black at L*=0, and the brightest white at L*=100.
The color channels, a* and b*, represent the coordinates of a color. The values a*=0 and b*=0 represent true neutral gray.
C* represents the chrominance. The difference ΔC* between two samples is considered to show a lighter (+) or darker (−) color. (May be illustrated as the amount of pigments)
h° represents the hue angle (in degrees), which is precisely the color.
The colorimetric space differences (L* C*)h° are easier to read and to interpret than
the colorimetric space (L* a* b*).
The color difference ΔE (delta E) is calculated between the chosen sample color L1 a1 b1 and the reference color L2 a2 b2 (or L1 C1 h1 and L2 C2 h2).
The result is calculated with the Colibri® Color software from Konica, in which the “CIE 2000” formula is used (the closest to the perception of the human eye).
The smaller the ΔE value, the more similar the color of the two products.
If ΔE is >1.5, the color difference is considered to be perceptible to the human eye.
The analyses were performed on mayonnaises at 15° C.
Equipment: Leica
The sample is dispersed in demineralized water and then colored with Lugol in order to reveal the starch granules. The iodine reacts with the amylose and forms spiral-structured complexes. A blue/violet color results if the starch is rich in amylose. Otherwise, the color of the starch granules remains brown/yellow.
The light microscopy observations give various information:
White light—×20 lens—magnification ×150
Characterization of the behavior of non-Newtonian fluids. The instrument imposes a specific stress or a strain on the fluid, and monitors the resulting strain or stress.
Analytical conditions: All the samples were analyzed for the rheology 1 day after the production date.
Repeatability of all the analyses: mean of three measurements
Accuracy: 5%
The flow results are expressed in a logarithmic-scale curve of viscosity (Pa·s) as a function of the shear rate (γ).
Noteworthy viscosity results may be noted at the following shear rates:
The yield point represents the minimum stress applied to place a product or a material in motion. The lower the result, the lower will be the effort required to place it in motion.
It is calculated with the Herschel Bulkley modeling, using the curve of stress as a function of the shear (resulting from the flow curve).
The results of the viscoelastic behavior (G′/G″) are expressed in a table with a modulus of elasticity (G′) which characterizes the solid part and the viscous modulus (G″) which characterizes the liquid part. The general interpretations of the analysis of the food products are “liquid-type behavior” if (G′<G″) or “solid-type behavior” if (G′>G″).
Sensory Evaluation (h+12 hours)
After use: On account of the temperature starting from 50° C. and of the shear process, the product is hot and quite fluid, more particularly for the thermally inhibited starch and the heat-modified starch “C” according to the invention.
After 12 hours of maturation at +5° C.: The products are equivalent, with the exception of a darker color for the thermally inhibited starch and the heat-modified starch “C” according to the invention. Furthermore, for the texture by spoon, the mayonnaise made with the heat-modified starch “C” appears a little more fluid.
For the texture in the mouth, the thermally inhibited starch and the heat-modified starch “C” according to the invention show virtually no difference, and the control with CLEARAM® CH2020 has a slightly thicker and more tacky texture.
There is no after-taste for the thermally inhibited starch and the heat-modified starch “C” according to the invention.
The modified starch CLEARAM® CH2020 is less damaged during the process. Moreover, for an equivalent dose, the thermally inhibited starch and the heat-modified starch “C” according to the invention have reduced viscosity performance.
Comparison with the test with CLEARAM® CH2020, as standard:
ΔL*: The two tests with the thermally inhibited starch and the heat-modified starch “C” according to the invention are darker than CLEARAM® CH2020.
ΔC*: NOVATION® 2300 shows a chroma very close to that of CLEARAM® CH2020, whereas the heat-modified starch “C” according to the invention shows a greater quantity of color.
Δh*: the thermally inhibited starch and the heat-modified starch “C” according to the invention show a different hue, but the heat-modified starch “C” according to the invention is more pronounced.
ΔE: NOVATION® 2300 shows a ΔE of less than 1.5, which theoretically indicates an imperceptible color difference with regard to CLEARAM® CH2020.
The heat-modified starch “C” according to the invention shows a ΔE of greater than 1.5, which means that the color of the sample is considered to be significantly different from that of CLEARAM® CH2020.
There is no more granular starch in the recipe, irrespective of the starch used, probably on account of the cooking process and the high level of shear.
All the samples have shear-thinning behavior (the viscosity decreases as the shear rate increases).
At 40 s−1, representing the mouthfeel, the viscosity is similar between CLEARAM® CH2020 and NOVATION® 2300. The heat-modified starch “C” is very slightly inferior.
The loss of viscosity relative to the shear rate is equivalent for the three samples. The rheological analysis confirms the sensory results, with a minor difference between the texture of the samples in the mouth.
According to the Herschel Bulkley model and with the measurement conditions, the samples showed no stress. The samples are also easy to pour.
For each analytical test, G′ is dominant relative to G″, which is proof that the products have “solid-type behavior”.
The firmness (i.e. the level G′) is similar for CLEARAM® CH2020 and the heat-modified starch C.
NOVATION® 2300 is slightly less elastic than the other samples that are more resistant.
This analysis also confirms the sensory results.
All the starches show the same weakness when subjected to high stress for the mayonnaise treated at elevated temperature.
All the granules are damaged.
Despite the fluid texture of the product after treatment, all the starches retrograde during the maturation and give the final sauce an acceptable texture.
A slightly thicker texture is noted for the control tests with CLEARAM® CH2020, but not very significant.
A significant dark color is noted for the mayonnaise with the heat-modified starch “C”.
Fruit preparations for yogurts often contain starch to enable their viscosity to be optimized and to make them stable throughout the shelf life of the product. They are mixed with the white mass of yogurt in proportions that may vary between 10% and 20% in general.
Heat-modified starch “C” according to the invention (prepared according to example 3);
The starch was tested in a strawberry fruit preparation.
All the tests have a very acidic pH, which may have an incidence on the degradation of the starch during the cooking process.
The state of cooking of the starch is monitored with a light microscope on the fruit preparation after cooking.
The preparation is colored with Lugol to improve the visualization of the starches.
Well-cooked (swollen) granules and also fragments of granules are observed. A portion of the granules was thus destroyed by the manufacturing process.
The heat-modified starch according to the invention is thus one of the products tested which best conserves its granular structure, which means that it is capable of withstanding the heat treatment conditions and the acidity conditions of the medium.
Bostwick flow (20° C., 90 g of product) after 12 days
It is found that the flow behavior is relatively similar between the starches, except for the test with the CLEARAM® CR0820 modified starch, which flows more.
The viscosity is measured after 1 day, 15 days and 30 days.
The values are given with an uncertainty of ±5%.
In the graph of
The heat-modified starch “C” gives a viscosity close to that obtained with NOVATION® 2300, and which increases slightly over time.
Finally, NOVATION® Prima 600 is the product whose viscosity is the lowest. It is stable on storage.
The four products were evaluated by a trained panel of 13 people. The method used is the flash profile method: the panel members themselves select the criteria which appear to be the most discriminating between the samples, and they then classify them according to the selected criteria.
The conclusion of the sensory analysis is as follows:
The sensory analysis thus confirms the results of the rheological measurements, with a thicker texture for the modified starch.
In conclusion, over all of these results, it is seen that the performance of the heat-modified starch according to the invention approaches that of NOVATION® 2300.
The resistance to shear under acidic conditions is higher than that of CLEARAM® CR0820, which is a starch commonly used in fruit preparations. The viscosity obtained is, on the other hand, slightly lower.
1) The Basification of Potato Starch is Performed According to the Following Steps:
2) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 210° C. and which are configured to subject the product to a residence time of the order of 30-35 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 19-22° C.
The RVA viscosity measurements are performed and are presented in the table below.
An analysis is performed comparing the products according to the invention with commercial products of the same category. The products derived from the invention are treated according to the following protocol:
Each example E-1, E-2 and E-3 of potato starches heat-modified according to the invention has improved stability during the process of use relative to the native starch: less gain in viscosity and less retrogradation are observed during the use of these starches. This is seen by measuring the drop with an RVA viscometer: the more negative the drop, the more resistant the starch will be to shear, to the acidity of the media and to the heat treatments.
Each example E-1, E-2 and E-3 of potato starches heat-modified according to the invention may be compared with other thermally inhibited products of the prior art based on potato starch, such as NOVATION 1900 or Beco Gel P4500. From the RVA viscometer results, the products that are the most resistant are the products derived from the invention.
Similarly, each example E-1, E-2 and E-3 of potato starches heat-modified according to the invention may be compared with the examples on waxy corn and notably the family D: the examples E-1, E-2 and E-3 of potato starches have a higher peak viscosity for the same measured solids content and have higher resistance to the process. The choice of the use of these starches will thus be made as a function of the intended application and thus of the shear, acidity and temperature conditions used.
1) The Basification of Cassava Starch is Performed According to the Following Steps:
2) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 210° C. and which are configured to subject the product to a residence time of the order of 20 to 35 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 22-27° C.
The RVA viscosity measurements are performed and are presented in the table below.
An analysis is performed comparing the products according to the invention with commercial products of the same category. The products derived from the invention are treated according to the following protocol:
Each example F-1, F-2 and F-3 of cassava starches heat-modified according to the invention has improved stability during the process of use relative to the native starch: less gain in viscosity and less retrogradation are observed during the use of these starches. This is seen by measuring the drop with an RVA viscometer: the more negative the drop, the more resistant the starch will be to shear, to the acidity of the media and to the heat treatments.
Each example F-1, F-2 and F-3 of cassava starches heat-modified according to the invention may be compared with other thermally inhibited products of the prior art based on cassava starch, such as CLARIA Bliss 570. From the RVA viscometer results, the products that are the most resistant are the products derived from the invention.
Similarly, each example F-1, F-2 and F-3 of cassava starches heat-modified according to the invention may be compared with the examples on waxy corn and notably the family D: the family D has a higher peak viscosity for the same measured solids content and has higher resistance to the process. The choice of the use of these starches will thus be made as a function of the intended application and thus of the shear, acidity and temperature conditions used.
1) The basification of pea starch is performed according to the following steps:
2) Heat treatment
The product thus obtained is heat-treated in VOMM continuous turboreactors in series, the nominal temperature of which is set at 210° C. and which are configured to subject the product to a residence time of the order of 10-25 minutes, and such that the difference in temperature between the nominal temperature and the temperature of the product leaving the reactor, known as Delta T, is a value of the order of 21-25° C.
The RVA viscosity measurements are performed and are presented in the table below.
An analysis is performed comparing the products according to the invention with commercial products of the same category. The products derived from the invention are treated according to the following protocol:
Each example G-1 and G-2 of pea starches heat-modified according to the invention has improved stability during the process of use relative to the native starch: less gain in viscosity and less retrogradation are observed during the use of these starches. This is seen by measuring the drop with an RVA viscometer: the more negative the drop, the more resistant the starch will be to shear, to the acidity of the media and to the heat treatments.
Each example G-1 and G-2 of pea starch heat-modified according to the invention may be compared with the examples on waxy corn and notably the family D: each example G-1 and G-2 has a lower peak viscosity for the same measured solids content and has a resistance to the process equivalent to that of the family D. The particular feature of the pea starch is the production of a very resistant product by means of a shorter residence time than for the other starting materials. The choice of the use of these starches will thus be made as a function of the intended application and thus of the shear, acidity and temperature conditions used.
For a 2 kg batch:
4. Cooking step on a 2 L Hotmix Pro Combi cooker:
5. Packaging/conditioning
6. Pasteurization
Autoclave at 85° C. for 45 minutes (equipment: Steriflow rotary bi-process ∅900 mm—1 basket—Ref.: NS 911 R MP FLW STEAM, year 2017, www.steriflow.com/en; Rotation: no (static)—heat treatment by pasteurization with water cascade)
At the end, the recipe is characterized by:
The level of cooking is determined by light microscopy (Leica microscope—×20 lens and×150 amplification). The sample is dispersed in demineralized water and then colored with Lugol for the purpose of revealing the starch granules. The iodine reacts with the amylose and forms spiral-structured complexes. A blue/violet color results if the starch is rich in amylose. Otherwise, the color of the starch granules remains brown/yellow.
The light microscopy observations give various information:
Several methods were used for the evaluation of the rheological properties of the sauces obtained.
a. Flow Measurement
Equipment: Anton Paar, MCR301 rheometer
Characterization of the behavior of non-Newtonian fluids. The instrument imposes a specific stress field or a strain on the fluid, and monitors the resulting strain or stress. The results are expressed in a logarithmic-scale curve of viscosity (Pa·s) as a function of the shear rate (γ). The result highlighted in this study is the viscosity at γ=40 s−1 (equivalent shear of the texture measured in the mouth).
Geometry: concentric cylinders
Analysis: Oscillation
Repeatability: average of three measurements
Accuracy: 5%
b. Bostwick Consistometer
The Bostwick machine is a consistometer. It consists of a rectangular stainless-steel tank separated into two parts by a guillotine door. The smaller section serves as a reservoir for the material to be evaluated. The larger section is equipped with ½ cm graduation marks starting from the door and going to the opposite end. The door is actuated by a spring. It is held in the bottom position by means of a lever arm. This mechanism ensures instant release of the product. The door slides vertically in grooves located in the side walls of the rectangular tank. The L-shaped tripping device holds the door in the bottom position. Two leveling screws are located close to the reservoir for the material to be tested and a spirit level is located at the other end of the machine.
For this evaluation, the tank was filled to its full capacity. The flow was measured over 30 s and 40 s. A mean was then determined (i.e. at 35 s) to have a value of two repetitions per sauce (at 20° C.).
The microscope allows a qualitative analysis of the level of cooking of the starch grains.
The microscopic observations of the ketchup made with NOVATION® 2300 show starch grains that are well cooked and a few less cooked grains.
The microscopic observation of the ketchup with CLEARAM® CH2020 shows starch grains that are well cooked, and also a certain amount of debris.
The microscopic observation of the heat-modified starch “C-3” according to the invention shows starch grains that are well cooked. The behavior of the granules is close to that of
NOVATION® 2300. Little debris is observed for these two starches. They appear to be more resistant than CLEARAM® CH2020 under these conditions.
a. Flow Measurement
The table below summarizes the flow measurement results:
The viscosity developed by the heat-modified starch “C3” is slightly lower than that of CLEARAM® CH2020 and of NOVATION® 2300.
b. Consistency (Bostwick)
The table below summarizes the consistency measurement results:
The ketchup made with the heat-modified starch “C3” has higher flow than the other two. This confirms the preceding flow data.
The ketchup made with the heat-modified starch “C3” is more fluid than the ketchup made with CLEARAM® CH2020 and NOVATION® 2300.
The heat-modified starch “C3” according to the invention has, in the ketchup sauce application, behavior close to that of the controls: CLEARAM® CH2020 (acetylated adipate crosslinked waxy corn starch), and the thermally inhibited starch NOVATION® 2300 but, however, develops less viscosity under the same conditions despite an equivalent level of swelling (cf. microscopic analysis).
| Number | Date | Country | Kind |
|---|---|---|---|
| 1762645 | Dec 2017 | FR | national |
| 1851658 | Feb 2018 | FR | national |
| 1853466 | Apr 2018 | FR | national |
| 1872125 | Nov 2018 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2018/053456 | 12/20/2018 | WO | 00 |
