WO2006103513A1

WO2006103513A1 - A process for the preparation of heat resistant seeds

Info

Publication number: WO2006103513A1
Application number: PCT/IB2006/000677
Authority: WO
Inventors: Sridevi Annapurna Singh; Dasappa Indrani; Mahendra Kumar Chikkananjaiah; Baragi Venkatesha Rao Sathyendra Rao; Gandham Venkateswara Rao; Appu Rao Gopala Rao Appu Rao; Prakash Vishweshwaraiah
Original assignee: Council Of Scientific And Industrial Research
Priority date: 2005-03-31
Filing date: 2006-03-28
Publication date: 2006-10-05
Also published as: EG24752A

Abstract

The present invention discloses a process for the preparation of heat resistant seeds, wherein the seed can tolerate a temperature in the range of 20 - 250 °C. The seeds are treated with hydrogen peroxide and coated with a solution of gum acacia, calcium carbonate and titanium dioxide.

Description

A PROCESS FOR THE PREPARATION OF HEAT RESISTANT SEEDS

FIELD OF THE INVENTION

The present invention relates to a process for the preparation of heat resistant seeds.

BACKGROUND OF THE INVENTION

The invention is aimed at obtaining seeds that are resistant to heat when exposed to high temperatures like baking, frying or roasting (20 - 25O⁰C). Several seeds like sesame, poppy, watermelon, cucumber seeds are added to or sprinkled over buns, bread and confectionery items to make the product more appealing or tasty. The high temperatures of processing result in the browning of seeds, which make the product less appealing.

There is a great demand for seeds that appear whiter and remain brighter and whiter after baking or frying or roasting. Sesamum indicum L. is the major commercial source of sesame and is primarily grown in India, China, Mexico and Sudan. The seeds vary considerably in color, size and texture of the seed coat. The color varies from white through various shades of brown, gold, grey, violet and black. Black and brown sesame commonly has a thicker seed coat. Sesame is utilized as the seed, ground or its oil. Sesame seed is often added to or sprinkled over various baked wheat flour foods, such as biscuits, breads and crackers. The white bold seeds are preferred due to their appealing appearance compared to other seeds.

The main drawback in the use of sesame in foods is the presence of fibrous hull fraction, which contributes to dark color, bitterness, and also high levels of oxalic and phytic acids. To reduce levels of these antinutrients, dehulling is essential.

Dehulled sesame seed finds application in the preparation of candies, confectionery items, bakery products and other traditional foods. Sesame seed is also used directly in a variety of confectioneries and bakery products. For this purpose, the seed has to be dehulled. The dehulled seed is white in color and is sprinkled on the products like buns after proofing and before baking.

CONFIRMATIOM COPY A common problem in the bakery industry is that the sesame seeds turn brown after baking due to the high temperature of baking. Sometimes, the seeds turn transparent on cooling the buns after baking. This decreases the sensory appeal of the product and prevention of browning is desirable for a premium product quality.

The process described in the present invention useful for the preparation of heat resistant seeds from plants like watermelon, cucumber, muskmelon and pumpkin and other edible seeds that need to appear bright after baking.

There are no references available currently regarding the heat resistance of sesame seeds after dehulling.

The main object of the present investigation is to provide a process for the preparation of heat resistant seeds.

Yet another object is to provide ready to use white sesame seeds for use in confectionery and bakery products.

Yet another object is to use the heat resistant seeds for sprinkling and baking buns without them turning brown after exposure to the high temperature of baking and cooling.

Yet another object is to obtain a product that does not turn transparent after the baked products are cooled.

Yet another object is to obtain a product, which is ready to use.

Yet another object is to incorporate an efficient and cost effective operation, which can be online in the production system.

Yet another object is to obtain a product that is having an attractive shape different from the untreated seeds.

In the drawings accompanying the specification Figure 1 represents 'Change in shape of treated seeds in comparison with untreated seeds (control)'. Figure 2 represents 'Whitening of the sesame seeds by treatment with hydrogen peroxide'. Accordingly, the present invention provides a process for the preparation of heat resistant seeds which comprised: a. immersing dehulled seeds in hot water at a temperature ranging from 30 - 100⁰C in the ratio of seeds : water :: 1 : 1 to 1: 10, b. adding hydrogen peroxide in the range of 0.25 - 5% vol/vol to the dehhuled seeds and hot water mixture as obtained from step a, c. boiling the mixture obtained in step b for a period of 0.5 -5 min, d. alternatively immersing the seeds in the said mixture of water and hydrogen peroxide at 25°C for a period of 15-30 min, e. dipping / spraying the seeds as obtained in step c and d with a solution of gum acacia (gum Arabic) in the range of 0.002 -0.02%, calcium carbonate in the range of 0.002 -0.02% and titanium dioxide in the range of 0.002 -0.02% in water to obtained coated seeds, f. drying the coated seeds in step e at a temperature of 30 - 90⁰C to obtain dry seeds having a moisture content of 3 - 6%,

In an embodiment of the present invention, the chemical used (hydrogen peroxide) dissociates to water and oxygen leaving no toxic remnants.

In another embodiment of the present invention, the seeds after treatment with hydrogen peroxide can be sprayed with a solution of gum acacia (gum Arabic) in the range of 0.002 -0.02%, calcium carbonate in the range of 0.002 -0.02% and titanium dioxide in the range of 0.002 -0.02% in water.

In yet another embodiment of the present invention, the treated dry seeds retain their whiteness when exposed to dry heat at a temperature of 20 to 25O⁰C for a period of 5 min to 40 minutes having a brightness value (L) of more than 65, 'a' value in the range 0.93 to -1.6, 'b' value in the range of 16.6 to 19.7 in the Hunter Lab Scale.

In still another embodiment of the present invention, the product after drying had moisture content of 3-6%. Detailed description of the invention

Water is heated to boiling in a steal cattle. Dehulled seeds are added to the hot water in the ratio 1:1 to 1:5 (seed: water).

Hydrogen peroxide is added to the hot water and seeds at added at the concentration of 0.25 to 0.5% volume by volume. The seeds are cooked for a period of 0.5 to 5 minutes at 100 degree centigrade. Alternatively, dehulled seeds can be taken in water in the same ratio of 1:1 to 1 :5 (seeds: water). Hydrogen peroxide is added at a concentration of 0.25 to 0.5% volume by volume and this is undisturbed for 30 minutes.

The treated seeds are drained and washed in cold water for 2 minutes.

The washed seeds are taken in the stainless steel container the washed seeds are sprayed with titanium dioxide, calcium carbonate and gum acacia in water at a concentration of 0.002 to 0.02% so that the seeds are coated with the solution. During the spraying the seeds are mixed. The coated seeds are dried at a temperature ranging from 30 to 90 degree centigrade to get heat resistant seeds. When seeds are sprinkled on proofed buns before baking and thereafter baked at temperature in the range of 20-260 degree centigrade to a time period of 5-40 minutes the seeds remain white.

Novelty:

Novelty and inventive steps of this invention lies in the fact to provide a process for the preparation of heat resistant seeds

1. Seeds when sprinkled on dough and baked, do not brown even if subjected to temperatures of 20 - 250⁰C for a period of 5 - 40 minutes.

2. The seeds have whiter and brighter appearance compared to the dehulled seeds

3. The seeds retain their shape even after exposure to the high baking temperatures 1

The process is further illustrated by the examples given below, which should not however be construed to limit the scope of the invention.

Example 1

2 kg dehulled sesame seeds, commercial white variety were immersed in hot water at 100⁰C in a ratio of 1: 2 (seeds : water). Food grade H₂O₂ is added to the boiling water at 1.5% level and further boiled for 1 min. The seeds are washed with cold water and dried in a hot air through flow drier at 6O⁰C for 4 hours. The dry seeds are packed in LDPE packets and stored at room temperature. The seeds were sprinkled on proofed wheat dough (for making buns) after brushing with water. The buns were baked at 200⁰C for 12 min and cooled and packed to obtain white sesame seed on the baked buns. The L, a, b values of unbaked coated seeds were 67.2, 0.3 and 19.3 compared to corresponding values of control being 62, 2 and 20.1 respectively. The L, a, b values of treated seeds were 62.9, 3.3, 17.9 respectively after baking. The corresponding L, a, b values for control seeds were 57.11, 6.89 and 19.11 respectively.

Example 2

3 kg of wet dehulled seeds, were treated with 2% H₂O₂ v/v in 1 : 2.5 ratio (seeds : water) at 100⁰C for 1 minute. The seeds are immediately washed to remove any residue of hydrogen peroxide. The seeds were dried at 70⁰C for 20 min in a fluidized bed drier to recover the heat resistant seeds. The retention of whiteness was tested by sprinkling the seeds on unbaked shaped buns in the proofing stage and baked at 220⁰C for 10 min. The L, a, b values of unbaked coated seeds were 65.6, 1.2 and 18.7 compared to corresponding values of control being 63, 1.5 and 18.2 respectively. The L, a, b values of treated seeds were 56, 6.3 and 17.8 respectively after baking. The corresponding L, a, b values for control seeds were 55, 6.7 and 17.26 respectively.

Example 3

100 g of dry sesame dehulled seeds were treated with 0.5% H₂O₂ at 70⁰C for 1 min and the seeds were sprayed with an aqueous solution of 0.002% gum acacia (gum Arabic), 0.02% calcium carbonate and 0.002% titanium dioxide. The seeds were dried at 70⁰C for 2 h in a hot air oven to recover the coated heat resistant seeds. The dried seeds were stored in polythene covers at 30⁰C. The retention of whiteness was tested by sprinkling on buns and baking at 240⁰C for 8 min. The L, a, b values of unbaked coated seeds were 74.1, -1.3 and 16.9 compared to corresponding values of control being 70.3, 0.15 and 17.4 respectively. The L, a, b values of treated seeds were 61.1, 3.6 and 18.1 respectively after baking. The corresponding L, a, b values for control seeds were 56, 5.5 and 16.95 respectively. Example 4

100 g of dry poppy seeds were treated with 1.0% H₂O₂ at 100⁰C for 1 min and the seeds were dipped in an aqueous solution of 0.002% gum acacia (gum Arabic), 0.002% calcium carbonate and 0.002% titanium dioxide. The seeds were dried at 70⁰C for 2 h in a hot air oven to recover the coated heat resistant seeds. The dried seeds were stored in polythene covers at 3O⁰C. The retention of whiteness was tested by sprinkling on buns and baking at 240⁰C for 8 min. The L, a, b values of coated unbaked poppy seeds were 65.2, 1.5 and 13.1 compared to 62.4, 1.9 and 13.9 in the control respectively. The

L, a, b of treated seeds were 49, 4.5 and 10.5 respectively after baking. The corresponding L, a, b values for control seeds were 46, 4.8 and 11.1 respectively.

Example 5

5 legs of wet sesame brown variety seeds were treated with 1.0% H₂O₂ at 100⁰C for 1 min and the seeds were dipped in an aqueous solution of 0.002% gum acacia (gum Arabic), 0.002% calcium carbonate and 0.002% titanium dioxide. The seeds were dried at 70⁰C for 20 min in a fluidized bed drier to recover the coated heat resistant seeds. The dried seeds were stored in polythene covers at 30⁰C. The retention of whiteness was tested by sprinkling on buns and baking at 220⁰C for 10 min. The L, a, b values of unbaked coated seeds were 63.4, -0.9 and 11.8 compared to control 60.2, -0.8 and 12.4 . respectively. The L, a, b values of treated seeds were 54, 2 and 14.5 respectively after baking. The corresponding L, a, b values for control seeds were 50, 3 and 14 respectively.

Example 6 200 g of dry dehulled water melon seeds were treated with 1.0% H₂O₂ at 100⁰C for 1 min and the seeds were dipped in an aqueous solution of 0.002% gum acacia (gum Arabic), 0.002% calcium carbonate and 0.002% titanium dioxide. The seeds were dried at 70⁰C for 3 h in a hot air oven to recover the coated heat resistant seeds. The dried seeds were stored in polythene covers at 3O⁰C. The retention of whiteness was tested by sprinkling on buns and baking at 220⁰C for 10 min. The L, a, b values of unbaked coated seeds were 58.2, 0.85 and 12.13 respectively compared to 54.1, 0.58 and 13.11 in the corresponding control samples. The L, a, b of treated seeds were 53, 2.2 and 13.8 respectively after baking. The corresponding L, a, b values for control seeds after baking were 51.5, 2.5 and 14.5 respectively.

The main advantages of this invention are: 1. The sesame seeds appear brighter than the seeds that are dehulled without any treatment.

2. The seeds are treated with a chemical at very dilute concentrations.

3. The seeds, on baking at high temperatures do not become brown but retain their whiteness. 4. The treated seeds have less microbial counts as food grade hydrogen peroxide destroys microorganisms.

5. The process is simple, with minimal steps and can be incorporated into the production line without any loss in productivity, time or extra cost.

6. The wet dehulled seeds can be treated without drying thereby eliminating one step of drying.

7. The chemicals used in the present invention are approved by PFA act of India.

8. The process is easy to scale up.

Claims

We claim:

1. A process for the preparation of heat resistant seeds which comprised : a) immersing dehulled seeds in hot water at a temperature ranging from 30 - 100⁰C in the ratio of seeds : water :: 1 : 1 to 1: 10, b) adding hydrogen peroxide in the range of 0.25 - 5% vol/vol to the dehhuled seeds and hot water mixture as obtained from step a, c) boiling the mixture obtained in step b for a period of 0.5 -5 min, d) alternatively immersing the seeds in the said mixture of water and hydrogen peroxide at 25°C for a period of 15-30 min, e) dipping / spraying the seeds as obtained in step c and d with a solution of gum acacia (gum Arabic) in the range of 0.002 -0.02%, calcium carbonate in the range of 0.002 -0.02% and titanium dioxide in the range of 0.002 -0.02% in water to obtained coated seeds, f) drying the coated seeds in step e at a temperature of 30 - 9O⁰C to obtain dry seeds having a moisture content of 3 - 6%,

2. The process as claimed in claim 1, wherein the chemical used (hydrogen peroxide) dissociates to water and oxygen leaving no toxic remnants.

3. The process as claimed in claims 1 & 2, wherein the seeds could be from different sources like sesame, poppy, water melon.

4. The process as claimed in claims 1 to 3, wherein the treated dry seeds retain their whiteness when exposed to dry heat at a temperature of 20 to 250⁰C for a period of 5 min to 40 minutes having a brightness value (L) of more than 65, 'a' value in the range of 0.93 to -1.6, 'b' value in the range of 16.6 to 19.7 in the Hunter Lab Scale

5. The process as claimed in claims 1 to 4, wherein the product after drying had moisture content of 3-6%.

6. A process for the preparation of heat resistant seeds substantially as herein described with reference to the examples and drawings accompanying this specification.