DESC:A PROCESS FOR PREPARATION OF HIGH-PROTEIN, LOW-FAT READY-TO-EAT EXTRUDED SNACK

FIELD OF THE INVENTION
The present invention relates to a process for preparation of high-protein, low-fat ready-to-eat extruded snack generally for the purpose of high-protein food products.

BACKGROUND OF THE INVENTION
The invention is situated against the backdrop of the complex and critical challenges associated with transforming legumes into a convenient and affordable ready-to-eat snack option as they have a distinct beany flavour which may reduce consumers acceptability.

The background description includes basics of the field of invention including a study of recent technologies along with a few patent literatures that may be useful in understanding the present invention. To know more about the background of the present invention, the details are explained herein below.

The ready-to-eat snack industry is evolving rapidly, with increasing demand as it is readily available and time-saving considering the fast-paced lifestyle of the majority of people living in urban areas. However, most of these snacks available in the market are highly processed with refined ingredients and lack essential nutrients. They often contain unhealthy ingredients such as excessive salt, sugar, trans fats that have been associated with the onset of obesity, diabetes and cardiovascular diseases. Use of indigenous and underutilized ingredients such as legumes with superior nutritional value in food processing has the potential to yield products with better outcomes. Therefore, there is an urgent demand for innovative approaches and technologies that can streamline the production of legume-incorporated snacks, and ultimately make these nutritious snacks more appealing and accessible to a broader consumer base.

Convenience foods are foods that has been pre-prepared commercially requiring little or no preparation by the consumers (Srinivasan and Kulkarni, 2019). One such type of convenience food is ready to eat (RTE) foods that are available for direct consumption without any further cooking. There has been a remarkable growth and immense popularity of convenience foods with increasing demand (Verma and Chawla, 2020). The market for these foods in India are expanding at a compounded annual growth rate of 20% per year (Dhir and Singala, 2020).

The extrusion cooking technology plays an vital role in food processing for the development of new and innovative food products like pasta, Textured Vegetable Protein (TVP), RTE such as snacks produced from cereals, baby foods, breakfast cereals, pet foods, dietary fibre, modified starch based products and traditional food products. Extrusion cooking is an HTST (High temperature short-time) process, it brings inactivation of raw enzymes, lowers the microbial activity from the finished products, denaturation of protein, deactivation of natural toxic substances, modification of lipids and gelatinization of starch (Faubian&Hoseney, 1982). The extruded products are sterile due to thorough gelatinization of starch and are very digestible (Seib, 1976). Extruded food materials have lower water activity (0.10-0.40) and because of the tide activity of cold extruded and hot extruded food are easily preserved for very long time (Bordoloi & Ganguly, 2014). In extrusion cooking, starchy, moisturized, and proteinaceous food material are processed through the application of mechanical shear, heat and pressure (Rossen & Miller, 1973; Smith, 1976). This is often done through the barrel and screw mechanism in extruder. The key effect is on nutritional qualities and physiochemical properties because the nature of food materials like protein, starch, and other ingredients are changed because of modification in chemical structures (Harper & Clark, 1979).

Cold extrusion and hot extrusion are the two types of extrusion methods in the extrusion technology. By using hot extrusion process, various types of food products are produced in which cereal based crispy snacks food, weaning foods from soybean, and sugar based confectionary. Hot extrusion process is also known as extrusion cooking. In cold extrusion, mixing and shaping of food is done by the non-cooking method, including pasta, biscuit dough. Equipment used for both hot extrusion and cold extrusion method is known as “Extruder”. The selection of an extruder is dependent on the desired final product. Hot extrusion is required to make the product in claim.

Single screw extruder contain only one screw which continuously rotates inside the barrel of single screw extruder, and usually these comes in different types. It works on simple and cheap to run operations such as dry extrusion (Wilson &Tribelhom, 1979). The regularly used single screw extruders have a consistent pitch (Harper, 1981). It was in 1946 that single-screw extruders were used for the extrusion cooking and expansion of corn snacks (Wiedman & Strobel, 1987).

In twin screw extruder, two rotating parallel screw having same dimension is present inside the barrel. Twin screw extruder is entangled than single screw extruders, and yet gives considerably better control and more versatility. Twin-screw extruders are typically more expensive than a single screw machine for the identical capacity (Lusas & Riaz, 1994). The flow of product will be uniform throughout the barrel as a result of positive pumping of screw flights. (Adekola, 2014)

Black turtle bean (Phaseolus vulgaris L.) is a nutrient-dense legume with excellent health benefits, making it a desirable ingredient for enriching the value of food products. This bean is low in carbohydrates and fat and is a rich source of protein and dietary fiber. The presence of vitamins and minerals, especially B vitamins, calcium, potassium, magnesium, iron and zinc, and bioactive compounds, such as phenolics, saponins with antioxidant effect, make their consumption advantageous and beneficial to health (Bento et al., 2021a, 2021b; Oliveira et al., 2017). Besides, the high content of soluble and insoluble dietary fibers, phytates, and polyphenols demonstrate numerous physiological benefits that lead to reduced risk of developing non-communicable diseases.

However, raw bean flour has problems related to its flavor, which can make the sensory aspects of foods formulated with bean flour unfeasible. This off-flavor is due to several compounds that contribute to the raw-bean flavor in bean-based products made with flours of raw grains (Simons and Hall, 2018). It also has a large amount of saponins (Bento et al., 2021a, 2021b) that according to Chitisankulet al. (2018) is the primary cause of undesirable bitter taste and astringent flavor in soybean/bean food products. Moreover, the presence of lipoxygenase enzymes favors the oxidation of fatty acids (e.g., linoleic, and linolenic acids) to hydroperoxides. These compounds can react even more to volatile and non-volatile compounds, in oxidation reactions promoted by treatments such as extrusion, or catalyzed by other endogenous enzymes, such as peroxygenase (Bento et al., 2020; Jiang et al., 2016; Silva et al., 2020). The oxidation of these compounds also gives the product an off-flavor.

In this context, the development of innovative method for preparing a high-protein, low-fat, ready to eat puffed snacks from Black turtle beans with an enhanced flavour and texture is required.

OBJECT OF THE INVENTION
The primary object of the present invention is to provide a process for preparation of high-protein, low-fat, ready-to-eat extruded snack.

Another object of the present invention is to produce a ready-to-eat extruded snack that has an enhanced nutritional profile without compromising on the taste and texture.

SUMMARY OF THE INVENTION
The present invention provides a process for the preparation of a high-protein, low-fat ready-to-eat extruded snack from a cereal and legume combination.

The object of the present invention is achieved by a process (100) for the preparation of a high-protein, low-fat, ready-to-eat extruded snack from a cereal and legume combination. Firstly, combining 70 percent cereal flour by weight and 30 percent legume flour by weight to form a composite flour. Next, forming a dough by adding 1 percent salt by weight and 20 percent water by weight to the composite flour. Thirdly, resting the dough for an hour and finally extruding the dough to form an extruded snack.

The another embodiment of the present invention is hand pounding the legume and coarsely splitting the legume using a motor and a pestle into two-three broken splits.
The another one embodiment of the present invention is dry roasting the legume at 80oC for 30 seconds and microwaving the legume under P100-1400 Watt for 95 seconds.

Another yet one embodiment is grounding the legume using a hammer mill of 0.2-mm screen to yield legume flour.

Another embodiment of the present invention is that the dough is extruded using a twin screw extruder.

Another embodiment of the present invention is that kneading the dough using a barrel in the extruder by enabling the twin screw extruder into semi-solid plasticized mass with temperature ranging higher than 100 degrees.

Another yet one embodiment of the present invention setting the temperature in heater 1 at 107oC, heater 2 temperature at 61oC, screw speed at 370 rpm, feeder speed at 25 rpm and cutter speed at 110 rpm and obtaining hot extrudated rod shaped puffed snack with thickness ranging 0.8-1cm and length ranging 3-3.5cm.

Another one embodiment of the present invention is that the cereal flour is whole maize flour.

Another one embodiment of the present invention is that the legume flour is black turtle bean flour.

BRIEF DESCRIPTION OF DRAWINGS
The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
Figure 1 shows a flowchart depicting the process to produce a high-protein, low-fat ready to eat puffed snacks.

Figure 2 shows the textural profile graph of the a) control snack and b) developed snack.

Figure 3 shows the real visual representation of the developed high-protein, low-fat ready-to-eat extruded snack.

DESCRIPTION
For promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as would normally occur to those skilled in the art are to be construed as being within the scope of the present invention.

The present invention provides a process for the preparation of a high-protein, low-fat, ready-to-eat extruded snack from a cereal and legume combination.

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 invention and are not intended to be restrictive thereof.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other, sub-systems, elements, structures, components, additional sub-systems, additional elements, additional structures, or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.

Embodiments of the present invention will be described below in detail with reference to the accompanying figures.

The present disclosure describes a process for the preparation of a high-protein, low-fat, ready-to-eat extruded snack from a cereal and legume combination (100). Figure 1 illustrates the process for the preparation of a high-protein, low-fat, ready-to-eat extruded snack from a cereal and legume combination. Firstly combining (101) 70 percent cereal flour by weight and 30 percent legume flour by weight to form a composite flour. Next step forming (102) a dough by adding 1 percent salt by weight and 20 percent water by weight to the composite flour. Thirdly, resting(103) the dough for an hour and finally extruding (104) the dough to form an extruded snack.

The legume is hand pounded followed by coarsely splitting the legume into two-three broken splits using mortar and pestle.

The legume is dry roasted at 80oC for 30 seconds and then microwaved under P100-1400 Watt for 95 seconds.

Lipoxygenase is one of the enzymes responsible for the development of the beany flavour in common beans. The process of roasting and microwaving the beans before grinding them helps to reduce the beany flavour in legume based products.

According to one embodiment the processed black turtle bean flour is mixed with whole maize flour. The composition of maize flour is 70-90% and the black turtle bean flour is 10-30%.

The composite flour is then fed into the extruder and is conveyed along the barrel with the help of twin screw extruder which also kneads the raw material into a semi-solid, plasticized mass with >100oC. This mass is finally forced through the die of required size and shape where the food expands and cools rapidly in case of hot extrusion (example: low density expanded foods and ready to eat puffed cereals). Extruding the composite flour as obtained using twin screw extruder with heater 1 at 107oC, heater 2 at 61oC, screw speed at 370 rpm, feeder speed at 25 rpm and cutter at 110 rpm to obtain extrudates puffed into desired rod shape with 0.8-1cm thickness and 3-3.5cm length to obtain high-protein, low-fat ready-to-eat snacks.

According to another embodiment of the invention, three hundred and fifty grams of black turtle beans were cleaned thoroughly to remove any stones, chaff and plant parts. After cleaned, black turtle beans were dry roasted at 80oC for 30 seconds, followed by exposure to microwave for 95 seconds to remove beany flavour. The processed black turtle beans were then ground in a hammer mill with a 0.2-mm screen which yielded fine-ground black turtle bean flour. Seven hundred grams of whole maize flour, 300 g of processed black turtle bean flour and 10 g of salt were mixed and 200 ml of water was added to yield a moist flour mix. To adopt the hot extrusion processing technique, a twin screw extruder was used to extrude the snacks. The composite flour was fed into the feeder at 20 rpm speed. The heater 1 was maintained at 107oC and heater 2 at 61oC with screw speed at 370 rpm and the cutter speed was set at 110 rpm to obtain rod shaped puffed extrudates of 0.8-1cm thickness and 3-3.5cm length. The product was cooled and then packed using a heat seal primarily in a HDPE packaging cover and secondarily in a double-layered (Aluminium + Polyethylene Terephthalate) packaging cover.

The developed snack is compared with a control snack made using 100% whole maize flour with with hot extrusion processing technique as described above. The sensory attributes of the control and developed snack were assessed using a nine-point hedonic scale. Higher the score, better the appearance, crisper, crunchier, adhesive texture, better the taste, flavour and overall acceptability. The developed snack had marginally higher scores for taste and marginally lower score for appearance (Table 1). The overall acceptability scores did not show any difference between the control and developed snack, indicating that the developed snack is on par with the control snack.

Table 1: Sensory attributes of the control and developed snack
Attributes Control Snack Developed Snack
Appearance 7.7 ± 1.20 6.33 ± 1.60**
Texture
Crispness 7.8 ± 0.88 7.43 ± 0.67NS
Crunchiness 7.6 ± 0.96 7.7 ± 0.98NS
Adhesiveness 5.66 ± 2.17 5.2 ± 2.32NS
Taste 6.26 ± 1.28 6.86 ± 1.27NS
Flavour 6.26 ± 1.41 6.23 ± 1.45NS
Overall Acceptability 6.88 ± 0.93 6.45 ± 0.68NS

Values are expressed as mean ± standard deviation of the triplicates; Means in the same row with ** indicates significant difference at p<0.01; NS indicates not significant.

The developed snack contained significantly higher energy (387.44 ±1.01 kcal), carbohydrate (81.30 ± 0.38 g), protein (12.50 ± 0.15 g) and crude fiber (1.52 ± 0.06 g) and lower fat (1.36 ± 0.13 g) than control snack. The developed snack had significantly higher calcium (316.99 ± 0.34 mg/kg), magnesium (1653.44 ± 0.18 mg/kg) and potassium (7419.38 ± 0.13 mg/kg) than control snack. The phytochemical composition of the developed snack namely total phenols (150 ± 0.92 µg/GAE) and total flavonoids (10.38 ± 0.60 µg/QE) were significantly higher than the control snack (Table 2). The textural properties of the developed snack showed significantly higher hardness (11613.54 ± 393.58 g), fracturability (9864.23 ± 89.52 g), cohesiveness (0.145 ± 0.007 g) and gumminess (156.75 ± 9.58 g) and a lower adhesiveness (-12.77 ± 0.14 g.sec) and springiness (0.03 ± 0.003 cm) when compared to control snack (Table 3).

High Protein:
According to FSSAI, a solid product can be claimed as high protein if the protein levels are >20% above the RDA/100g (Recommended Dietary Allowances). Our product has 12.5g of protein/100g. For an average Indian adult man weighing 65kgs, the RDA for protein is 54g/day. Intake of 100g of our product will meet 23% of their protein needs. For an average Indian adult woman weighing 55kgs, the RDA for protein is 46g/day. Intake of 100g of our product will meet 27% of their protein needs. Hence, this product can be claimed as a high-protein snack.

Low Fat:
According to FSSAI, a solid product can be claimed as low-fat if the fat levels are <3g/100g. Our product has only 1.36g of fat/100g. Hence, this product can be claimed as a low-fat snack.

Table 2: Proximate, micronutrient and phytochemical composition of the control and developed snack.
Parameters Control Snack Developed Snack
Proximate Composition
Energy (kcal) 362.18 ± 0.58 387.44 ±1.01**
Carbohydrate (g) 76.52 ± 0.08 81.30 ± 0.38**
Protein (g) 8.62 ± 0.03 12.50 ± 0.15**
Fat (g) 3.36 ± 0.04 1.36 ± 0.13**
Crude Fibre (g) 1.26 ± 0.05 1.52 ± 0.06**
Ash (g) 3.25 ± 0.04 3.32 ± 0.39NS
Micronutrient Profile
Calcium (mg/kg) 118.12 ± 0.28 316.99 ± 0.34**
Magnesium (mg/kg) 872.62 ± 0.45 1653.44 ± 0.18**
Iron (mg/kg) 945.39 ± 0.87 278.65 ± 0.09**
Potassium (mg/kg) 3495 ± 0.62 7419.38 ± 0.13**
Phytochemical Composition
Total Phenols (µg/GAE) 130.8 ± 1.37 150 ± 0.92**
Total Flavonoids (µg/QE) 7.52 ± 0.24 10.38 ± 0.60*

Values are expressed as mean ± standard deviation of the triplicates; Means in the same row with ** indicates significant difference at p<0.01 and * indicates at p<0.05.

Table 3 shows the textural properties of the control and developed snack

Properties Control Snack Developed Snack
Hardness (g) 5949.62 ± 252.30 11613.54 ± 393.58**
Fracturability (g) 3266.01 ± 31.74 9864.23 ± 89.52**
Adhesiveness (g.sec) -7.36 ± 0.38 -12.77 ± 0.14**
Springiness (cm) 0.34 ± 0.01 0.03 ± 0.003**
Cohesiveness (g) 0.034 ± 0.007 0.145 ± 0.007**
Gumminess (g) 108.03 ± 7.72 156.75 ± 9.58*
Chewiness(cm) 3.60 ± 0.07 6.71 ± 0.13**

Values are expressed as mean ± standard deviation of the triplicates; Means in the same row with ** indicates significant difference at p<0.01 and * indicates at p<0.05.

Table 4 shows the physical properties of the control and developed snack.
Properties Control snack Developed snack
Bulk Density (g/cm3) 1.09 ± 0.03 1.33 ± 0.08*
Expansion Ratio 11.32 ± 0.23 9.90 ± 0.12**

Values are expressed as mean ± standard deviation of the triplicates; Means in the same row with ** indicates significant difference at p<0.01 and * indicates at p<0.05.
In table 4, it can be inferred that the developed snacks have a marginally increased bulk density (1.33 ± 0.08 g/cm3) and lower expansion ratio (9.90 ± 0.12) than control snack.

Figure 2 shows the textural profile graph of the a) control snack and b) developed snack.

Figure 3 shows the real visual representation of the developed high-protein, low-fat ready-to-eat extruded snack.

,CLAIMS:CLAIMS
We claim:
1. A process (100) for the preparation of a high-protein, low-fat, ready-to-eat extruded snack from a cereal and legume combination, the process comprising:
combining (101) 70 percent cereal flour by weight and 30 percent legume flour by weight to form a composite flour;
forming (102) a dough by adding 1 percent salt by weight and 20 percent water by weight to the composite flour;
resting (103) the dough for an hour; and
extruding (104) the dough to form an extruded snack.

2. The process as claimed in claim 1, wherein the legume is hand pounded followed by coarsely splitting the legume into two-three broken splits using mortar and pestle.
3. The process as claimed in claim 1, wherein:
dry roasting the legume at 80oC for 30 seconds; and
microwaving the legume under P100-1400 Watt for 95 seconds.

4. The process as claimed in claim 1, wherein grounding the legume using a hammer mill of 0.2-mm screen to yield legume flour.

5. The process as claimed in claim 1, wherein the dough is extruded using a twin screw extruder.

6. The process as claimed in claim 1, wherein extruding the dough comprising:
kneading the dough using a barrel in the extruder by enabling the twin screw extruder into semi-solid plasticized mass with temperature ranging higher than 100oC.

7. The process as claimed in claim 1, wherein extruding the dough comprising:
setting the temperature in heater 1 at 107oC, heater 2 temperature at 61oC, screw speed at 370 rpm, feeder speed at 25 rpm and cutter speed at 110 rpm; and
obtaining hot extrudated rod shaped puffed snack with thickness ranging 0.8-1cm and length ranging 3-3.5cm.

8. The process as claimed in claim 1, wherein the cereal flour is whole maize flour.

9. The process as claimed in claim 1, wherein the legume flour is black turtle bean flour.