Effect of Incorporation of Finger Millet Flour (Ragi Flour) on Texture Profile of Chicken Nuggets

Chicken nuggets, a widely popular ready-to-eat meat product, are favoured by consumers for their palatability, convenience and nutritional content (Pakseresht et al., 2022). However, growing health awareness and dietary preferences are influencing consumer choices, leading to a demand for healthier and more diverse meat products. The quality of chicken nuggets is significantly affected by factors like processing, raw material and non-meat ingredients, affecting their nutritional value and consumers acceptability (Yogesh et al., 2013). In this context, chicken nuggets fortified with finger millet flour could cater the market demand by providing a convenient, nutritious and functional food option. Moreover, finger millet is gluten-free, making it suitable for individuals with celiac disease or gluten sensitivity, further broadening its market appeal (Muthamilarasan and Prasad, 2015).
         
Finger millet (Eleusine coracana), commonly known as ragi, is a small-seeded cereal widely cultivated in Asia and Africa (Nagaraja et al., 2025). It is known for its exceptional nutritional profile particularly calcium, iron and dietary fibre and resilience to harsh environmental conditions (Devi et al., 2014; Amadou et al., 2013). However, finger millet remains underutilized, largely due to limited awareness crop of its nutritional quality and health benefits (Desai and Dutta, 2023). India is a leading producer of finger millet, contributing around 2.2 million tons and the crop is well adapted to thrive in harsh agro-climatic conditions (https://www.icrisat.org/crops/finger-millet/overview) Studies have shown that the functional properties of finger millet flour, such as water-holding capacity, emulsifying properties and fat-binding ability, can significantly improve the quality of meat products (Rao et al., 2018). Additionally, the fiber in finger millet can act as a natural stabilizer, improving the texture and cohesiveness of the meat emulsion, which is essential for maintaining the integrity of the nuggets during processing and cooking (Rathod and Annapure, 2017). Moreover, finger millet is relatively inexpensive compared to other grains, making it a cost-effective ingredient for food manufacturers (Belton and Taylor, 2004).
       
Incorporating finger millet flour into chicken nuggets can potentially offer several health benefits. The high fiber content of finger millet can aid in digestion and help maintain healthy bowel function, reducing the risk of constipation and other gastrointestinal disorders (Gull et al., 2014). Finger millet are rich in antioxidants due to the presence of various polyphenols, offering several health benefits, such as reduced risk of cardiovascular diseases, cancer, diabetes and neurogenerative disorders (Nakarani et al., 2021). The slow-release carbohydrates in finger millet can help regulate blood sugar levels, making it a suitable option for diabetic individuals (Shobana et al., 2013). Studies have demonstrated better quality attributes of different types of finger millet flour enrobed chicken nuggets and cutlets (Akhila et al., 2023; Gamit et al., 2020).
       
However, incorporation of ragi flour into chicken nuggets may encounter challenges in sensory acceptance due to millet’s lower viscoelastic properties compared to refined wheat flour, which can affect the texture and overall appeal (Siroha and Banger, 2024). The distinctive taste and color of finger millet flour can alter the flavor and appearance of the final product, which may not be acceptable to all consumers (Rao and Bhattacharya, 2013). To overcome these challenges, it is essential to optimize the level of finger millet flour used in chicken nuggets to balance its nutritional benefits with desirable sensory attributes. Based on the potential benefits and disadvantages related to sensory attributes of finger millet, we evaluated the texture profile of chicken nuggets incorporated with different levels of finger millet flour concentration for the development of nutrient rich chicken nuggets.

This study was carried out during the period from February 2023 to January 2024 in the Livestock Product Technology department, College of Veterinary Science and UAT, Kumarganj, Ayodhya (U.P.). Fresh raw boneless meat from 6-week-old broilers was procured from nearby local meat shop and were transported to the laboratory in the polythene pouches to maintain cleanliness and hygiene. The skin, subcutaneous fat, tendons and separable connective tissue were trimmed off. The dressed meat was packed in polyethylene (HDPE- 0.93-0.97 g/cm³) and kept at -18±1°C overnight for aging, thawed and subsequently used for product formulation.
     
Deboned meat, after thawing at room temperature, was cut into small pieces (around 3 cm size) and minced using a meat mincer (4 mm plate). During chopping in a bowl chopper, salt, sodium nitrite and sodium tripolyphosphate were added to the minced meat. Subsequently, refined vegetable oil, finger millet flour, condiments and spice mix were added to achieve proper emulsion. A recipe comprising lean meat, salt, spices, condiments and preservatives was followed for the preparation of chicken nuggets, as detailed in Table 1.


       
During chopping in a bowl chopper, salt, sodium nitrite and sodium tripolyphosphate were added to the minced meat and chopped for about 30 sec. After addition of ice flakes, it was chopped again for 1.5 min followed by incorporation of vegetable oil slowly and chopping was continued for 2 min. Condiments, spices were added and chopping continues for 2 min. Ragi flour (Finger millet) was added @ 0%, 3%, 6% and 9% to the emulsion and chopping was continued until proper emulsion was achieved, while the formulation for the control group was kept same, as detailed in Table 1.
       
Chicken nuggets were prepared by filling the above formulated emulsions in separate stainless steel moulds of dimensions 14 cm x 7 cm x 3 cm to achieve a proper shape and steam cooked for 35 minutes with internal core temperature maintained at 75± 2^oC during cooking. After cooking and cooling to room temperature, whole nuggets were uniformly cut into 2 cm pieces. The pieces were compressed to 75% of their height for two cycles using a Stable Microsystems Texture Analyzer (TA-XT2) equipped with a 1/2o flat surface plunger. The instrument was programmed for a 40 kg load cell and a cross-head speed of 2 mm/sec. Hardness, cohesiveness, gumminess, springiness and chewiness were obtained using the available computer software attached to the texture analyser. The experiment was repeated five times with three samples in each repetition.

The data in Table 2 analyzes the impact of Finger Millet Flour (ragi flour) incorporation at different levels (0%, 3%, 6% and 9%) on the texture profile of chicken nuggets. The parameters assessed include hardness, springiness, stringiness, cohesiveness, chewiness and gumminess, which collectively describe the physical and mechanical properties of the nuggets. These attributes are critical to the sensory perception of the product, as they directly influence mouthfeel, chewability and overall acceptability.

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The addition of ragi flour significantly influenced the texture profile of chicken nuggets. Hardness is a measure of the force required to compress the product, indicating how firm or tough the chicken nuggets feel when bitten. Hardness progressively decreased from 11.74±0.04 N/cm² at 0% to 8.80±0.02 N/cm² at 9%, indicating a softer texture due to increased moisture retention. This softening effect can be advantageous, particularly for consumer groups that prefer less dense and easier-to-chew textures, such as children and older adults. However, excessive softness at higher Ragi levels (9%) may compromise the structural integrity and traditional bite associated with chicken nuggets, potentially reducing their appeal to consumers accustomed to firmer textures.
       
Springiness measures the extent to which a product returns to its original shape after being compressed, reflecting its elasticity or resilience. Springiness declined with increasing ragi flour levels, from 9.82±0.04 cm at 0% to 8.70±0.02 cm at 9% suggesting a reduction in elasticity, likely due to disruption of the protein matrix. While reduced elasticity can make the nuggets feel more yielding and less rubbery, excessive loss of springiness could detract from the expected textural experience, making the product feel less cohesive and more fragile during handling and consumption.
       
Stringiness measures the tendency of the product to form strands or fibers when pulled or bitten, which can negatively affect chewability if excessive. A decrease in stringiness from 17.02±0.02 at 0% to 14.52±0.02 at 9% was observed with increase in levels of ragi flour. This downward trend suggests that ragi flour helps reduce the fibrous or stretchy nature of the nuggets, likely by interfering with the meat protein network responsible for string formation. Reduced stringiness is generally favorable for chicken nuggets, as it improves bite quality and eliminates the undesirable sensation of fibrous or tough textures. This effect aligns well with consumer preferences, especially in products like chicken nuggets, where a smooth and cohesive bite is highly valued. Ragi Flour’s ability to mitigate stringiness can enhance the mouthfeel of the product, making it more enjoyable and easier to consume.
       
Cohesiveness measures the internal bonding strength of the product, indicating how well it holds together when compressed. Cohesiveness also decreased from 0.95± 0.01 at 0% to 0.80±0.01 at 9%, indicating a weaker internal structure, which could impact product integrity at higher ragi levels. Lower cohesiveness at higher Ragi levels may be attributed to the dilution of meat proteins, which are responsible for the strong binding properties in chicken nuggets. While some reduction in cohesiveness can contribute to a softer texture, excessive loss may negatively affect the handling, packaging and eating experience.
       
Chewiness is a composite measure derived from hardness, cohesiveness and springiness, reflecting the effort required to chew the product. Chewiness showed a declining trend with increase in ragi flour levels, from 65.44±0.05 N/cm at 0% to 60.46±0.11 N/cm at 9%, making nuggets easier to chew, particularly for children and elderly consumers. However, manufacturers must ensure that the product retains enough substance to provide a satisfying bite, as overly soft textures may be perceived as unappealing by some consumers.
       
Gumminess reflects the stickiness or density of the product during chewing, combining elements of hardness and cohesiveness. Gumminess decreased with higher ragi levels, from 8.56±0.01 N/cm² at 0% to 7.6±0.02 N/cm² at 9%, contributing to a lighter and more enjoyable mouthfeel experience. By reducing gumminess, Ragi Flour contributes to a lighter and more enjoyable mouthfeel, making the product more appealing to a wider range of consumers.
       
Several studies have been conducted to study the effect of incorporation of different types of flours on the texture of chicken nuggets. A study analyzed texture profile parameter of oat flour incorporated chicken nuggets and observed significantly increased hardness values, contrarily significantly decreased springiness values for oat treated chicken nuggets (Santhi and Kalaikannan, 2014).  Devatkal et al., (2011) showed significantly increased hardness, gumminess and chewiness values in 10% sorghum flour (SF) incorporated chicken nuggets, while 5% SF incorporated chicken nuggets did not show any significant difference from control. Kumar et al., (2013) also reported increased firmness, chewiness and elasticity values in chicken nuggets incorporated with 3-5% soybean skin flour.
       
The results demonstrate that ragi flour significantly influences the texture profile of chicken nuggets, primarily by softening the product, reducing stringiness and gumminess and making it easier to chew. These changes are particularly beneficial for creating a product that appeals to consumers seeking tender and succulent textures. However, higher ragi levels (9%) may compromise cohesiveness and elasticity, potentially reducing the structural integrity and traditional bite associated with chicken nuggets. A study by Dahriya et al., (2024) suggested development of functional chicken nuggets by incorporating kodo millet flour at the level of 6 %. One study indicated that incorporation of 3.5% pearl millet flour to the chicken nuggets have shown good acceptability, however, they did not go for the treatment above 3.5% pearl millet (Akhila et al., 2023). Similarly, another study demonstrated that the addition of black rice flour at 1-5 % level resulted no significant changes in the physicochemical qualities of chicken nuggets (Richa et al., 2024). The linear reduction in hardness and gumminess observed with increasing ragi levels reflects a progressive alteration in meat matrix interactions due to starch and fiber content in ragi. Additionally, the natural binding properties of ragi may contribute to moisture retention, as evidenced by the softer texture in the 6% group. Our findings suggests that although increasing ragi levels results in significant reduction in texture attributes, however, a moderate inclusion of ragi levels (3-6%) may offer an acceptable well-rounded texture profile for creating innovative chicken nugget formulations that leverage the functional benefits of ragi flour while maintaining consumer appeal.

Our study suggested that finger millet flour (ragi flour) can be used as a replacer of refined wheat flour in preparation of chicken nuggets without compromising its texture. By incorporating ragi at controlled levels, manufacturers can offer a product that meets the demands of modern consumers for healthier, softer and more enjoyable processed meat products.

The authors are grateful to College of Veterinary Science, A.N.D.U.A.T., Kumarganj, Ayodhya (U.P.) for providing facilities to complete this research.

The authors declare that they have no conflict of interest.