AU689341B2

AU689341B2 - Fast rehydrating pulses

Info

Publication number: AU689341B2
Application number: AU39251/95A
Authority: AU
Inventors: Nico Ammann; Philipp Paul Meyer
Original assignee: Societe des Produits Nestle SA; Nestle SA
Current assignee: Societe des Produits Nestle SA
Priority date: 1994-11-17
Filing date: 1995-10-25
Publication date: 1998-03-26
Anticipated expiration: 2015-10-25
Also published as: KR970700007A; CZ289729B6; NZ295658A; CN1138822A; ZA959763B; EP0712582A1; BR9506514A; ES2170761T3; DE69429811T2; MY114201A; EP0712582B1; JPH09507762A; RU2144297C1; HUT75127A; CN1068187C; KR100309060B1; AR000251A1; CA2179538A1; PL315620A1; AU3925195A

Description

Fast rehydratmg pulses

Field of the invention

The present invention relates to a process for preparing fast rehydratmg pulses.

Background of the Invention

Various processes for preparing fast cooking or instant pulses, comprising a precooking and a drying of the pulses, are known. One of the problems encountered when carrying out these processes s the bursting and/or partial disintegration of tne pulses. During this bursting, due to differences m surface tensions between the sκιn and the cotyledon, the pulse may split into two halves which separate and cause it to resemble wings of an insect. This phenomenon is known to a person skilled m the art by the term butterflying. To avoid this disintegration, the suggestion has been made to carry out a controlled drying of the cooked pulses.

In the case where cooking takes place under pressure, a person skilled in the art may also contemplate a controlled relaxation of tne steam pressure, followed by a controlled cooling of the pulses, m other words contemplate carrying out the steps of relaxing the steam pressure and cooling the pulses carefully and above all slowly, for example. US 4,273,796 describes a process for preparing fast rehydratmg pulses which do not burst during the drying which follows cooking, m which the pulses are cooked, at atmospheric pressure or under pressure, in a 5-7% sugar solution, ana dried using any Known αry g process such as lyophilization or drying unαer vacuum, with hot air, using infrared or using microwaves, for example. Summary of the Invention

The object of the present invention is to propose a process for preparing fast renydrat g pulses which comprises a step of cooking under pressure but which avoids the bursting of the pulses, without it being necessary to cook tnem in a sugar solution or to provide for a controlled relaxation of the pressure and/or a controlled cooling of the pulses. To th s end, m tne process according to the present invention, tne pulses are cooked with steam under pressure, cooleα oy placing them under vacuum and απed.

It was found, n effect, surprisingly, that, in orαer to avoid the bursting cf pulses cookeα witn steam in a vessel under pressure, the pulses can be cooled directly by placing them unαer vacuum, that is to say by αrawmg off steam and/or condensed vapour (flash cooling; , witnout taking special precautions, to a resiαual pressure in the vessel which is significantly below atmospheric pressure.

In otner words, tne present process makes it possible not only to preserve the integrity of the pulses, whicn nardly ourst at all, but also to cool the pulses significantly more quickly than if, for comparison, the steam pressure s relaxed carefully in order to reestablisn atmospheric pressure in the vessel, and the pulses, which are still at a temperature of 100°C after this pressure relaxation, are then cooled slowly.

Detailed description of the Invention

To carry out tne present process, the starting material can oe commercial fresh or dry pulses, in particular dry soya, bean, pea or lentil seeαs, for example.

It s preferable for the starting material to be pulses navmg a water content of 40-80*, this water content being that of the fresh pulses or that of the dry pulses rehydrated by soaking.

In the latter case, namely in order to rehydrate dry pulses, they may be soaked beforehand for 3-30 h at 15-30°C in pure water or in water with the addition of 0-0.5% of NaHS0₃ and/or of 0-1% of C_DH₅Na₃θ7 as agent for stabilizing the colour, for example.

The pulses may be cooked at 105-140°C for 3-40 mm in a vessel in which a pressure equal to the saturation vapour pressure at the chosen temperature can be established, for example. The steam atmosphere may be created in the vessel either by vaporization of an appropriate amount of water, or by direct injection of steam, the air initially present in tne vessel being driven out of the latter at the beginning of the process, for example.

The pulses may be cooled to a temperature of

20-80°C while placing them under vacuum by drawing off steam and/or condensed vapour to a residual pressure below 300 mbar and maintaining this vacuum for 2-10 min, for example.

It is important, and can be most especially recommended, not to allow the pulses to come into contact witn cold air before the end of this cooling step.

After the cooking and cooling, the pulses may be dried to a residual water content of 3-10%, for example. This drying may be carried out under vacuum at 40-60°C, at a pressure of 20-40 mbar and for 5-20 h, for example.

The pulses thereby obtained have a very similar appearance to that of corresponding dry but uncooked pulses. The proportion of burst pulses is, in particular, exceptionally low. These pulses may be rehydrated generally in

5-10 m in boiling water, or even m 3-4 mm in water at 70-80°C for small-sized pulses such as lentils, for example. They may be used as they are or as an ingredient m a dehydrated mixture for fast cooking soup, for example.

The examples below illustrate various embodiments of the process for preparing fast rehydratmg pulses according to the present invention. The percentages are expressed therein by weight.

Example 1

Commercial dry navy oeans are soaked for 6 h in water at room temperature containing 0.25% of NaHS0₃ and 0.5% of C₅H₅Na₃0-, after which they have a water content of 54.0%. The soaked pulses are rinsed for 5 mm in running water. The pulses are placed in an autoclave. Steam is injected directly into the autoclave wnile first driving out the air contained in the latter. The temperature of the pulses is brought to 120°C in 2 mm. The temperature is maintained at 120°C for 12 mm. The pulses are then placed under vacuum by drawing off the steam to a residual pressure of 250 mbar. This vacuum is maintained for 3 mm, after which the autoclave is opened.

The cooked pulses have a water content of 50.6%. Burst pulses amount to only a few per cent.

The pulses are dried at 50°C at 30 mbar for 14 h.

The pulses thereby obtained have a residual water content of 6.2%. They have the appearance of the original dry navy beans and rehydrate in 6 mm in boiling water.

Examples 2-4

Dehydrated dwarf kidney bean, red kidney bean and Borlotti bean seeds are prepared in a manner similar to that described in Example 1 for navy beans.

The values of the different working parameters during the different steps, as well as the water contents of the pulses, are collated in Table 1 below, in which the corresponding values presented in Example 1 have also been recorded.

Table 1

The pulses thereby obtained have the appearance of the respective original pulses. Very few have burst. Their colour has remained excellent. They rehydrate in 5-10 min in boiling water.

Claims

1. A process for preparing fast rehydratmg pulses, in which the pulses are cooked with steam under pressure, cooled by placing them under vacuum and dried.

2. A process according to Claim 1, m which the starting material is pulses having a water content of 40-80%, which are cooked at a temperature of 105-140°C for 3-40 mm and cooled to a temperature of 20-80°C while placing them under vacuum by drawing off steam and/or condensed vapour to a residual pressure below 300 mbar and maintaining this vacuum for 2-10 mm.

3. A process according to Claim 1, m which the pulses are dried to a residual water content of 3-10%.

4. A process according to Claim 3, in which the pulses are dried under vacuum at 40-60°C, at a pressure of 20-40 mbar for 5-20 h.

5. Fast rehydratmg pulses obtained by the process according to one of 'Claims 1 to 4.