Claims:1. A process for preparing a sweetening composition from Mahua flowers, the process comprising:
mixing the flowers with pectinase and cellulase enzymes;
heating the mixture at a temperature in the range of 30 to 45 °C for at least 10 minutes, followed by heating the mixture at a temperature in the range of 70 to 90 °C for at least 5 minutes;
filtering the heated mixture to separate solid material;
subjecting the filtrate to alkali treatment to adjust pH of the filtrate in the range of 6 to 8; and
filtering the pH adjusted filtrate to obtain the sweetening composition.

2. The process as claimed in claim 1, wherein the flowers are dry flowers.

3. The process as claimed in claim 2, wherein the dry flowers are treated with water prior to the mixing with the pectinase and cellulase enzymes.

4. The process as claimed in claim 2, wherein the dry flowers are mixed with water and the enzymes simultaneously.

5. The process as claimed in any of claims 1 to 4, wherein the flowers are pulverized to a size in the range of 1 to 5 mm prior to the mixing with the pectinase and the cellulase enzymes.

6. The process as claimed in any of claims 1 to 5, wherein each of the pectinase and the cellulase is added to the flowers at a concentration in the range of 0.001 to 1% w/w.

7. The process as claimed in any of claims 1 to 6 further comprising concentrating the sweetening composition.

8. The process as claimed in claim 7, wherein the sweetening composition is concentrated in the range of 65-90 Brix by either heating or vacuum concentration or both.

9. The process as claimed in any of claims 1 to 8, wherein yield of the sweetening composition is 80 to 90 %.

10. The process as claimed in any of claims 1 to 9, wherein the alkali is selected from the group consisting of MgO, CaO, KOH, K2HPO4 and a combination thereof.

11. The process as claimed in any of claims 1 to 10 further comprising spray drying the sweetening composition.

12. The process as claimed in any of claims 1 to 11, wherein the separated solid material is mixed with water to obtain a second mixture and the second mixture is heated at a temperature in the range of 70 to 90 °C for at least 5 minutes to extract residual sugars present in the separated solid material.
, Description:FIELD OF INVENTION

The present disclosure relates to a process for preparing a sweetening composition from Mahua flowers. More specifically, the present disclosure relates to an enzymatic process for preparing a sweetening composition from Mahua flowers and the sweetening composition obtained from such process.

BACKGROUND

Madhuca longifolia or Madhuca indica commonly know as Mahua is a tropical tree found largely in north and central India, Nepal and Sri Lanka. It is cultivated as well as harvested in the wild for its oleaginous seeds, flowers and wood. The flowers of Mahua tree are edible and can be eaten raw or cooked. The fresh flowers have a characteristic ‘cooked rice’ flavor, which increases on drying. Mahua flowers are known to have medicinal properties and are used for treating conditions such as diarrhea, skin and eye diseases and headache. The flowers are used by the tribal and local people for making various fermented and non-fermented food products. The flowers are rich in sugars and are therefore used for making natural sweetening compositions.

Indian patent application no. 201841035402 discloses a process for preparing a sweetener from Mahua flowers. According to the disclosed process, the flowers are chopped using a bowl chopper. The chopped flowers are soaked in hot water. Thereafter, a syrup is extracted from the soaked flowers at temperature range of 116 to 134°C.

Indian patent application no. 201631039011 discloses a process and an apparatus for preparing a juice concentrate from Mahua flowers. In the disclosed process, dry flowers are collected, de-seeded and washed. The juice is extracted from the flowers and then transferred to a holding tank where it is maintained at 4.4 to 54.4 °C to remove the tartrates. Thereafter, the juice is centrifuged to remove any foreign materials. In order to prevent undesirable fermentation, the juice is then heat treated at about 65.5 to 82.2 °C. The heat treatment can be done before and after centrifugation.

Indian patent application 954/DEL/2009 discloses a process for preparing a nutra-sweetener composition form Mahua flowers. The process involves extracting an extract from the flowers, filtering the extract using fine filters, clarifying the filtered extract by heating at a temperature in the range of 80°C to 85°C, and concentrating the clarified extract by open pan steam heating or vacuum concentration.

SUMMARY

The present disclosure relates to a process for preparing a sweetening composition from Mahua flowers. The process comprises mixing the flowers with pectinase and cellulase enzymes; heating the mixture at a temperature in the range of 30 to 45 °C for at least 10 minutes, followed by heating the mixture at a temperature in the range of 70 to 90 °C for at least 5 minutes; filtering the heated mixture to separate solid material; subjecting the filtrate to alkali treatment to adjust pH of the filtrate in the range of 6 to 8; and filtering the pH adjusted filtrate to obtain the sweetening composition.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the disclosed composition and method, and such further applications of the principles of the disclosure therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.

Reference throughout this specification to “one embodiment” “an embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase “in one embodiment”, “in an embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The present disclosure relates to a process for preparing a sweetening composition from Mahua flowers.

The process comprises mixing the flowers with pectinase and cellulase enzymes, heating the mixture of the flowers and the enzymes at a temperature in the range of 30 to 45 °C for at least 10 minutes, followed by heating the mixture at a temperature in the range of 70 to 90 °C for at least 5 minutes, filtering the heated mixture to separate solid material, subjecting the filtrate to alkali treatment to adjust pH of the filtrate in the range of 6 to 8; and filtering the pH adjusted filtrate to obtain the sweetening composition.

The process may be used for preparing the sweetening composition from fresh flowers or dry flowers. The dry Mahua flowers have moisture content in the range of 10 to 15 %, preferably in the range of 8 to 10 %.

In an embodiment of the present disclosure, the flowers are dry flowers, which are treated with water prior to mixing with the pectinase and cellulase enzymes. In another embodiment, the dry flowers are mixed with the pectinase and cellulase enzymes and water simultaneously.

The fresh or dry flowers can be ground, chopped or pulverized before mixing with the pectinase and cellulase enzymes. In accordance with an embodiment, the flowers are pulverized to a size in the range of 1 to 5 mm. The pulverization may be carried out by any known device, for example a pulverizer or a mixer.

In accordance with an embodiment, each of the pectinase and the cellulase enzymes is added to the flowers at a concentration in the range of 0.001 to 1% w/w. In an embodiment the concentration is in the range of 0.001 to 0.1%. In an aspect, the ratio of the pectinase and the cellulase enzymes is in the range of 1:1.

In accordance with an embodiment, the mixture of the flowers and the pectinase and cellulase enzymes is heated at a temperature in the range of 30 to 45 °C for 20 to 30 minutes. In a specific embodiment, the mixture of the flowers and the pectinase and the cellulase enzymes in heated at a temperature in the range of 35 to 40 °C.

In accordance with an embodiment, the mixture is heated at a temperature in the range of 30 to 45 °C for at least 10 minutes, followed by heating the mixture at a temperature in the range of 75 to 85 °C for 5 to 10 minutes.

The filtering of the heated mixture to separate solid material can be performed by any suitable filter or method known in the art. Suitable examples of filters include but are not limited to muslin cloth, cellulose filter pad, silica and celite.

Examples of suitable alkali that may be used in the process include but are not limited to Magnesium oxide (MgO), Calcium oxide (CaO), dipotassium phosphate (K2HPO4) and potassium hydroxide (KOH). Treating the filtrate with the alkali helps in reducing or removing the polyphenol content of the filtrate, which helps in improving the taste of the sweetening composition.

In accordance with an embodiment, the separated solid material is mixed with water to obtain a second mixture and the second mixture is then heated at a temperature in the range of 70 to 90 °C for at least 5 minutes to extract any residual sugars that may be present in the separated solid material. The extract containing the sugars may be suitably processed as above to obtain additional sweetening composition.

In accordance with an embodiment, the process further comprises concentrating the sweetening composition to form a sweetening syrup. In accordance with an embodiment, the sweetening composition is concentrated in the range of 65 to 90 Brix. The sweetening composition may be concentrated by heating or vacuum concentration or both. In an example, the sweetening composition is concentrated using a rotary vacuum evaporator. The sweetening syrup so obtained may be heated to 80 °C and stored in suitable containers and sealed.

The sweetening composition or the sweetening syrup may be spray dried to form a sweetening powder. The spray drying may be performed at a temperature in the range of 120 to130 °C. Suitable drying aid(s) may be used to obtain a free flowing sweetening powder. Examples of the drying aid(s) include, but are not limited to, maltodextrin, gum arabic and a combination thereof.

The sweetening powder may be mixed with anticaking agent(s), for example 2% fused silica. It may then be packed under nitrogen in suitable containers and sealed.

In accordance with an embodiment, yield of the sweetening composition obtained according to the disclosed process is 80 to 90 %.

EXAMPLES

The following examples are provided to explain and illustrate the preferred embodiments of the present disclosure and do not in any way limit the scope of the disclosure as described:

Example 1: Preparation of a sweetening composition from Mahua flowers

100gm of dried Mahua flowers were taken from APMC market, Vashi, Mumbai. The flowers were soaked in 250 ml water. In the soaked solution, 0.1% pectinase and 0.1% cellulase enzymes were added and the mixture was heated at 45?C for 30 minutes. The heated mixture was then pulverized using a kitchen mixer. The pulverized mixture was then heated at 80?C for 5 minutes. The heated pulverized mixture was filtered using a muslin cloth to obtain a filtrate and the solid material. To the solid material, 250 ml water was added to obtain a second mixture, which was heated at 80?C for 5 minutes. The heated second mixture was filtered using the muslin cloth to obtain a second filtrate. Filtrates were combined and pH was adjusted to 8.2 with MgO and allowed to stand for 7 minutes at 30?C. The resultant solution was filtered again through muslin cloth to remove precipitated polyphenols. The resultant filtrate was concentrated using rotary vacuum evaporator to 30 Brix to obtain a syrup. The syrup was heated at 80?C to obtain the sweetening composition.
Spray drying of syrup: To the 30Brix concentrate syrup, maltodextrin was added at 3:1 ratio of syrup to solids. Spray-drying was carried at 120-125 °C and the outlet temperature of 60 °C.

Table 1: Nutritional fact of the sweetening composition (per 100 gms) obtained above
Fat 2.4 %
Protein 10.2 %
Carbohydrates 76.6 %
Total Sugar 31.0 %
Crude fiber 10.5
Energy 390 Kcals

Example 2: Adjustment of pH of the Filtrate

Before pH adjustment, the filtrate has pH in the range of 5.0-5.2. Due to this, the taste of the filtrate is significantly astringent. The pH is therefore increased to 8.0 to 8.5 to enhance the sweetness of the filtrate. Different pH modifying materials were used to adjust the pH of the filtrate, the table below summarizes the results:

Table 2: Effect of different pH modifying materials

S.No. Material pH adjusted to Filter aid % transmission of filtered extract Taste
1. MgO 8 None 58.3 Sweet
2. K2HPO4 8 None 67.7 Sweet
3. KOH 8.2 Silica 57 Sweet
4 KOH 6.5-7.0 Hiflo 46.8 Sweet
5. NaOH 6.0-6.5 None 45.8 Slightly alkaline and Sweet
6. No adjustment 5.2 Hiflo 40.8 Astringent

Observations: An increase in pH to 7.0 and above using NaOH results in an alkaline taste, which is not acceptable. Sweet taste is obtained using MgO, K2HPO4 and KOH. K2HPO4 gave the best results as can be observed from % transmission of the extract data in the above table. However, KOH gave best results with respect to the efficiency of the filtration.

Example 3: Reduction of ‘cooked rice’ flavor

The ‘cooked rice’ flavor of Mahua flowers is due to the presence of acetyl pyrroline and acetyl pyrrole. The concentrations of acetyl pyrroline and acetyl pyrrole were calculated in dry Mahua flowers, and the sweetening composition in syrup and powder forms was obtained in accordance with the present disclosure. The table below summarizes the results.

Table 3: Acetyl pyrroline and acetyl pyrrole content
Sr No. Product 2 Acetyl 1 pyrroline concentration (mg/kg) 2 Acetyl pyrrole
(mg/kg)
1. Dry flower 0.13 0.28
2. Sweetening composition – syrup 0.2 0.346

Observations: Approximately 2.8 kg of flowers gives 1 kg of the sweetening composition in syrup form. The concentration of acetyl pyrroline and acetyl pyrrole in the sweetening composition was observed to be reduced by approximately 3 times its theoretical calculated value.

Example 4: Sensory profile of the Sweetening composition

The spray dried sweetening composition was used to prepare a ‘10% solution’. The sensory profile of the 10% solution was compared with the sensory profiles of 7.5% jaggery solution and 5% sugar solution. The table below summarizes the results:

Sweetness Taste Aroma Mouthfeel Color Overall
7.5% jaggery solution 8 8.25 8.25 7.25 7 8
5% sugar solution 9 9 9 9 9 9
10% solution 7.25 7.25 7 7.25 7 7.25

Observations: Eight participants took part in the blind test. 10% sweetening composition solution was observed to be similar to 5% sugar solution and 7.5% jaggery solution in sweetness intensity. When compared to sugar, three participants out of eight found a bitter note in the 10% solution. When compared to jaggery, none of the participants found a bitter note in the 10% solution. Thus, sweetness of the sweetening composition was found to be more similar to jaggery than sugar by most participants. This was expected because the spray dried sweetening composition contained 25% gum arabic.

INDUSTRIAL APPLICABILITY

The disclosure provides an economical and efficient process for preparing a sweetening composition from Mahua flowers. The process is not only suitable for fresh flowers, but may also use dry flowers, which are easier to handle and transport and have longer shelf life. The process provides high yields of the sweetening composition. The sweetening composition obtained from the process is substantially free of the ‘cooked rice’ flavor.