AU642509B2 - Whole flour from lupin, procedure for obtaining and applications thereof - Google Patents

Description

The present invention relates to the field of agro-alimentation. More particularly, it relates to an original flour of lupin, especially mild white lupin (species Lupinus albus). The present invention also relates to the procedure for obtaining the flour and its applications! The lupin is a member of the family of leguminous plants. It is a proteinaceous plant with seeds that are rich in proteins and consist of. two cotyledons in the form of flat beans surrounded by a protective tegument. The seeds are currently used as food for humans or animals due to their particularly interesting nutritional composition. For example, the kernels, ground or in their original form, can be used as food for cattle and, husked or unhusked, can also be consumed, in pickling brine by humans.

These seeds have been researched extensively because they are an important source of proteins. The seeds are rich in fibres, though poor in iron. The essential amino acids and fat acids they contain are well balanced, and the seeds are free from cholesterol.

Lupin seeds are currently most widely used in the form of whole 9 seeds. However, they can be also be used in the form of flour, obtained by husking and milling by means of milling machines employing brushes or hammers. The flour so obtained can be used as a nutritional complement, for example, as a substitute for milk in food for calves.

Flours obtained by conventional techniques exhibit, at the optimum level, the following granulometry: .30 to 50% of particles measuring less than 30 p; 50 to 90% measuring less than'100 p.

The granulometry is limited to the values described above because of the relatively high proportion of fat matter contained in lupin seeds (circa The seeds cannot be readily ground because they adhere to one another in the pores of the gitd-et.

J: 2 i Applications of lupin flour in the field of cosmetology are disclosed in the document GB-A-2 178 657. After a final process of p ticles 98% of which have a diameter less than 80 p, can As. 5 i e-S be obtained. B-er-s i of this order of magnitude are the smallest that can be used with this type of fat seeds.

This document (GB-A-2 178 657) also predicts the possibility of increasing the fat matter content of the seeds to facilitate the S t04Ai process of ~blt Employing a procedure for bolting by the wet method (WO-A-8 300 419) enables very fine granulometries to be obtained. However, the flours obtained as a result of these treatments are not complete; fat matter is reduced or even absent and soluble elements are eliminated.

To utilize lupin seeds as an ingredient or a nutritional complement especially in alimentary preparations, the presence of the whole assembly of constituents of lupin seeds is highly desirable. Therefore, it is highly desirable that whole flours be utilized. However, whole flours obtained by prior-art methods do not mix or disperse well in nutritional media of any type, and this limits the scope of alimentary utilization of the products.

An objective of the present invention is to propose a novel to product based on lupin seeds, which is entirely natural, capable of being incorporated more easily in different types of alimentary preparations and usable as an ingredient.

The present invention relates to a whole flour of husked lupin, especially of mild white lupin (species Lupinus albus), consisting of Sparticles, at least 90% of which having a size less than 100 u and at least 60% having a size less than 30 p. Preferably, at least 95% of the particles have a size less than 100 p, and at least 60% a size •less t\an 30 1, and at least 20% a size less than 10 u.

Such a flour exhibits surprising solubility and stability in suspension, and a highly advantageous emulsifying capacity.

The present invention also relates to a procedure for obtaining •such a flour. This procedure is implemented in a dry manner and comprises: cleaning the seeds; subjecting them to a thermal treatment, particularly a treatment with hot air on a fluidized bed with parameters adjusted.to obtain the product desired.

husking the seeds by means of for example, a husking procedure using impact; separating the cotyledons from the hulls; initially grinding the cotyledons by means of a hammer or brush grinder having grids of 500 to 2000 1.

obtaining an ultrafine milling product of the flour by passing the pre-ground product on at least a pair of smooth pressing cylinders with pressure adjusted to achieve the desired granulometry.

The ultrafine flour so obtained is rich in proteins and fibres but poor in iron. This product is balanced in amino acids and fat acids, and free from cholesterol. Fat matter which is naturally and finely dispersed in tissues remains particularly stable in suspension.

This flour can be very easily dispersed in a dry, pasty or liquid medium. Its stability in suspension and its emulsifying capacity together with its ease of handling, enable it to be used S for numerous purposes, for example, as a protein complement, or as a source of alimentary fibres. Due to its structural and chemical characteristics, the ultrafine flour is suitable for use as an ingredient in light recipes. The flour can also be used in pork-butchers' shops, to prepare potted meat or fine pasty *o sausages; in cereal products used in panification, as an ingredient of the soft part of bread or of special breads, in pastry, and biscuit making and in alimentary pastes; in sauces and cooked dishes; o" a as a source of proteins and fibres in light recipes....

ui The flour can also be used as a partial substitute for powdered *milk (either for adults or instant consumption), and to prepare novel products based on vegetal proteins. Finally, it can be used in cosmetology.

In addition to its excellent capacity for retaining water and Sfat matter, the product also exhibits textural properties, and a neutral taste in alimentary preparations.

The original procedure for treating lupin seeds, described in the following, consists of performing consecutively the operations summarized in Table I.

TABLE I Cleaning seeds Calibrating Grading Baking (p oe Sor-/ Husking by impact

A.

A.

C A S Separating Kernels Hulls Preliminary grinding Final milling on cylinders i1- Cleaning'seeds This operation consists of, after receiving and storing whole S' seeds, carefully removing the great majority of impurities or alien seeds present. Impurities may be alien bodies of the powder type, metal elements or cobbles elements with density higher than a des that of the seeds).

The treatment can be performed by means of for example, a series of machines of the following types: a separator with a vibrating screen, whose grids are selected to suit the raw material being processed, and in particular, the impurities and alien seeds which may be present.

'9 -a magnetic apparatus, for example, one employing a permanent magnet whi.ch can remove metal elements, such as iron wire or nails from the seeds.

a suction-type cobble-remover to remove heavy elements.

If properly used, this technique can eliminate 99% of impurities and alien seeds.

2. Calibrating The operation of calibrating is optional. 'rhis operation can be performed by means of vibrating graduated water channels to sort seeds in accordance with their sizes. The operation of sorting is useful in later treatment of products of well-defined categories.

The means used must also eliminate most of, the smashed and/or attacked seeds.

3. Thermal treatment C..This operation is also optional, depending on the desired product. The operation, however, offers non-negligible advantages, and oat therefore, it is preferable that the seeds be subjected to it. The S...operation consists of baking lupin seeds preferably, with hot air on a fluidized bed at temperatures adjusted to achieve the results 4 4desired. Hot air used for baking can reach a temperature ranging from the ambient temperature to ZOOOC. Temperatures in the range from 85 0

C

to 070 0 C are preferred (hot air temperature at the inlet).

This treatment has an initial mechanical effect which aims at facilitating the operation of husking. The operation allows the two cotyledons to be retracted in the tegument.

The thermal treatment also has a physico-chemical effect: it destroys anti-nutritional factors and lipoxidase. Hence., rancidness is prevented and the flour obtained keeps longer.

00CThe characteristics of the final product vary with the parameters selected during this stage, and particularly, with the 00000parameters of time and temperature. Regarding this point, it should be noted that the proportion of insoluble proteins increases with the degree of baking.

This thermal treatment, carried out using hot air on a fluidized bed, comprises placing the seeds in an enclosure equipped with a hot U 6 air blower. The stay time can be varied between 30 seconds and 12 minutes by using means for driving the seeds.

As a guide, baking seeds at 120 0 C for 6 ntinutes leads to excellent results with regard to both the final husking and solubility of proteins and the conservation of the flour.

4. Husking This operation can be carried out by means of a centrifugal impact husker. The rotary velocity of the machine, in the order of 3500 rotations/minute, is selected according to the product to be treated, and the results desired, whether the kernels are broken or not.

This velocity is also dependent on the thermal treatment of the seeds to be used.

This type of machine, which involves striking, can be replaced by systems which use rollers equipped with abrasive surfaces.

5. Separating hulls and cotyledons This technique is a very delicate operation to perform. The o, to process can be carried out optimally by using techniques of separating e* with air. The conventional means used in the field of milling can be conveniently used to separate the elements: no more than 2% of hulls are left in the cotyledons, and no more then 1% of kernels in the hulls.

The husked seeds are subsequently cooled before they are ground to avoid the risk of bursting.

6. Preliminary grinding The purpose of this operation is to prepare the product used in the final milling.

The cotyledons can be preliminarily ground by means of a grinder equipped with hammers associated with screens having pores of a diameter between 500 and 2000 u. As a guide, a pre-grinding grid equipped with perforations of a diameter of 1.5 mm gives good results; the flow af the pre-ground flour is adequate for the subsequent treatment of the untrafine milling product.

a.

a.~ 4 4 *6S* 4 i a 7. Ultrafine milling product pr-ercc1~ The process of ultrafine milling is, carried out by passing a regular layer of the pre-ground product through at least one pressing device consisting of a pair of smooth cylinders.

The passage of the pre-ground product between the cylinders, whichtrotate in opposite directions, causes the product to be crushed and cells to be broken.

This or these pressing devices arew equipped with means for controlling the amount of pressure exerted on the product. This pressure is generally less than 80 bars, and preferably, in the vicinity of 10 bars.

Preferably, the two cylinders of any pair should not rotate at the same velocity. The difference in velocity enables the quality of the process of milling to be improved, leading to the formation of flakes or scales of the product.

For example, the arrangement can comprise three successive twocylinder groups. The pre-ground product flows between each pair of cylinders due to gravity. Preferably, the velocity of the cylinders is adjusted to obtain identical differential velocities that are consecutively reversed from one group to another During the process of ultrafine milling, the cylinders become heated, and it is feeerea-/ to cool them by means an internally circulated water flow. The cooling means are adjusted in such a manner that the temperature of water at the outlet never exceeds 32 0

C.

varieties of lupin can be used. However, a mild variety is preferred due to the absence of alkaloids.

Example 1 An example of obtaining the product according to the present invention from seeds of mild white lupin is described below.

The seeds are subjected to the treatment described previously, at a baking temperature of 120 0 C and a process of pre-grinding with 500 1i grids. The milling product so obtained is then passed on smooth ft 4.

S S i i~i II ly I-J cylinders adjusted to obtain ultrafine granulometries. The whole flour so obtained is analyzed a~'id found to exhibit the characteristics shown in Table Il.

TABLE II HuMt: atound 8% Comnosition of dry matter) Proteins (N *6.25) 45.0 Fat matter 12.0 Soluble sugars 13.5 Mineral m?.tter Total fibres 25.5 -cellulose 2.0 -hemicellulose 3.0 l ]~pin 0.7 Amidon Main fatt acids (in of dry matter) >Soluble fibres: 10.5 Insoluble fibres: 15.5 )(Van Soet's method) Saturated fat-acids 14% (50% o Unsaturated fat acids 86% (70% unsaturated) oleic acid -linoleic acid -limolenic acid 7% Soluble nitrogen total nitrog~en: Non-Droteiti nitroaen total nitroaen: f which being palmitic acid) of which being mono- *mg 4 ~1t* b a.

4 0g*W *5 Si S

S

S *S*

S

a S..

5 at PH 6.5) 11.3% Antitrypsic factors:- 1000 TIU/g (Absence) composition in amino acids: of dry matter) Aspartic acid 4.3 4eucine Threonine 1.5 Tyrosine Serine 2.1 Phenylalanine Glutainic acid 8.7 Histidine Proline 1.7 Lysine Glysine 1.6 Arglnine Alanine 1.3 Methionine Valine 1.8 Cystine Isoleucine 1.9 Tryptophane 2.1 1,6 0.9 2.2 4.6 0.3 Composition of the mineral matter,

K

P

0% of dry matter) 1.40 0.54 0.11 0.18 0.16 0.07 8 PPM 48 ppm 232 ppm Folic acid Vit C Vit BI Vit B2 Vit A 6.1 X 10-3 PPM 2 ppm 0.57 mg /100 g 0.24 mg /100 g 0.01 mg 100 g 9 Granulometric afialysis of the ultratine flour can be accomplished using a conventional method,~ for instance, by using a l a s e r a p p a r a t u s x F t f e S i e From the results shown in Table I1kthe cuive (SI Own in Figure IV which illustrates the granulometric distribution of the particles can be drawn.

TABLJE III .3 3 @33 010 0 The ultrafine produic. of this floor comprises 95% of particles having sizes less than 100 It 75% of particles of sizes less chan P, and 50% of particles having sizes less than 10 p.

WI.,

FIGURE IV Grarilametry: Ultrafine lup,',n flour 7 0 6 E so a..

I I a a *0g.

9 a.

a I FIGURE VI Granu2loxmetry: "Cld ultrafine lupin flour 1.00' 0 4la*SS a .611 o aa a a.

a a..

a.

6S a..

S

4 P-4 c.

x 4Pmicrons Q vc4 c~le sze2) Example 2 Another test is conducted using an identical product that is not subjected to the baking stage, and passed into the milled material through 700 p grids. A granulometric analysis of the flour so obtained gives the results shown in Table V and Figure VI.

TABLE V

I,.

*u

S

S

SSS*

o *e5S

SQ

x (microns) less than x 1.8 8.88 2.2 10.72 2.6 12.19 3 13.41 3.6 14.95 4.4 16.79 5.2 18.58 6.2 20.97 7.4 24.15 8.6 27.56 10 31.47 12 36.3 15 41.5 18 45.09 21 48.41 25 52.93 30 57.77 36 62.81 42 67.38 72.99 79.12 72 85.04 86 89.96 102 93.63 122 96.47 146 98.86 174 99.84 206 100 4* 1 6* 4 s The milling product of this flour comprises 95% of particles having sizes less than 100 1, 60% of particles having sizes less than p, and 22% of particles having sizes less than 10 1.

Example 3 This test is conducted under milling conditions identical to..

those of Example 2, but the seeds are subjected to preliminary baking at 120 0

C.

P k ,A r i 0O 4@ *I C

S

C

S.

5 *5

S

*r S

CS

Ce eS

S

12 A granulometric analysis of the flour obtained gives the results (X p •r--te fs _X shown in Table VII and Figure VIII.

TABLE VII x (microns) less than x 1.8 10.51 2.2 12.66 2.6 14.34 3 15.7 3.6 17.42 4.4 19.43 5.2 21,38 6.2 24.01 7.4 27,54 8.6 31.35 35.7 12 40.99 46.51 18 49.91 21 53.18 25 57.74 30 62.51 36 67.33 42 71.57 76.69 82.19 72 87.38 86 91.64 102 94.75 122 97.17 146 '98.95 174 100 206 100 The milling product of this flour comprises 97% of particles having sizes less than 100 i, 64% of particles of sizes less than i, and 28% having sizes less than 10 p.

It can be seen from the curves shown in Figuresi VI and VIII that baking has a small influence on the granulometry, reducing the granulometry of the particles which leads to better husking.

Figure IX shows the dependence of the solubility of different lupin flours on the pH.

Curve 1 corresponds to a coarse flour obtained from lupin by a prior-art technique involving solely grinding with a hammer grinder associated with screens having grids of 700 p, and no thermal treatment.

13 FIGURE VIII Granulcuietry. "'Hot" ultrafine lupin flour ZT11? zZ:Tflfl .11 I 1 10 AOO 1000

C.

S

CCC

C C OC* S cc

C

CCC~

CC..

a.

C

CC

x(in microns) %C Z* -,e FIGURE IX

C

*COCCC

C

eeoc

.C

CU S

C.

S

eve

C.

S

C CCC

C

ewe...

a C 16N6 25 so.Lubilised 10,00 6 50,00 40.00 :i0,00 20,00 10,001 0 I 2 005 B 9 10 II 12 13 44 Curve 2 corresponds to an ultrafine lupin flour obtained by the method according to the present invention, involving no thermal treatment.

Curve 3 corresponds to an utrafine lupin flour obtained by the method according of the present invention under the conditions identical to those imposed on the product of curve 2, but are thermally treated at 120 0

C.

Comparing curve 1 with curves 2 and 3, it can be seen that granulometry plays an important role in determining solubility, especially at pH 's higher than 5.5 which are generally used in the field of agro-alimentation.

As a result of grinding under pressure, cells do not remain intact; they burst leading to an increase in solubility of proteins and fat matter.

Since there is a correlation between the solubility and the functional properties of the product, such as emulsifying gelling or thickening capacity, it can be deduced that the ultrafine flour according to the present invention offers better functional properties than flours obtained by prior-art techniques.

Furthermore, since the flour according to the present invention can be easily dispersed in a dry, pasty or liquid medium, it can be readily incorporated in alimentary preparations.

Due to its good functional properties, the flour according to the present invention can be used in alimentary preparations as a textural agent. Thus the flour can be used to play the role of an k* emulsifier for proteins (for instance, as a partial substitute for caseinates' a substitute for fat m tter to retain a similar texture in light products) or for its capability to retain water.

Different types of flour can be obtained by varying the parameters involved in milling, or modifying the baking time and temperature. These values are selected to achieve the desired characteristics of the flour.

Thermal treatment offers certain advantages, especially its ability to destroy antinutritional factors and lipoxygenase. Thermal treatment also leads to an improvement in the microbiological state of the product. The conditions of thermal treatment are to be selected to achieve the desired final product.

Claims (13)

1. A whole flour of husked lupin characterized in that the flour consists of particles of which: at least 90% have a size less than 100 u; and at least 60% have a size less than 30 p.

2. A whole flour of husked lupin characterized in that the flour consists of particles of which: at least 95% have a size less than 100 u; at least 60% have a size less than 30 u; at least 20% have a size less than 10 p.

3. A whole flour of husked lupin as claimed in any of claims 1 and 2 \L, and characterized in that the flour consists of particles of which: at least 98% have a size less than 100 p; at least 75% have a size less than 30 p; at least 50% have a size less than 10 p.

4. A whole flour of husked lupin as claimed in either of claims 1 through 3 and characterized in that the flour is constituted from mild white lupin, species Lupinus albus., v prc\>oc sa~ o le-~irNCOr-O Pk s

5. A procedure for btaining.lupin flour comprising* ckc.\o. re cnIy oneof Ce- o O4- Compri sLT\r cleaning seeds; husking them; separating cotyledons from hulls; and grinding said cotyledons; and characterized in that the process of grinding comprises, on one 6 Shand, pre-grinding cotyledons by means of a hammer grinder having grids between 500 and 2000 p, and on the other hand, achieving an ultrafine milling product from the flour by means of cylinders.

6. A procedure as claimed in claim 5 and characterized in that it comprises, following the cleaning of the seeds, thermal treatment of •the seeds.

A procedure as claimed in claim 6 and characterized' in that the thermal treatment comprises a treatment with hot air on a fl'tidized bed for from 30 seconds to 12 minutes at a temperature between 85 0 C and 170 0 C.

8. A procedure as claimed in any of claims 5 through 7 and i V\ characterized in that the seeds are husked by ilpact. 16

9. A procedure as claimed in either of claims 5 through 8 and characterized in that the ultrafine milling product is obtained by passing the pre-ground product through a plurality of smooth pressing cylinders, the pressure applied to each pair of cylinders, being adjusted to achieve the desired granulometry.

A procedure as claimed in claim 9 and characterized in that the ultrafine milling product is obtained by passing the pre-ground product on a series of three successive pairs of cylinders, each cylinder pair being subjected to a pressure of the order of 10 bars and the cylinders of each pair rotating in opposite directions, and at different velocities to each other.

11. A procedure as claimed in claim 10 and characterized in that the differential velocity of all three cylinder pairs is identical, but consecutively reversed from one pair to the next.

12. Application of the product according to any of claims 1 through 4 as a protein complement in alimentary preparations. o .o

13. Application of the product according to any of claims 1 to 4 as a textural V. agent in alimentary preparations. DATED this 6th day of July, 1993 LA NOELLE SERVICES WATERMARK PATENT TRADEMARK ATTORNEYS THE ATRIUM 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA