Project – Nutritional Composition and Consumer Acceptability of Snack Products Developed from Plantain and Bambara Groundnut Flour

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

The development of nutritious, affordable and acceptable foods from locally available crops has become increasingly important in addressing food and nutrition challenges, particularly in developing countries where diets may depend heavily on a limited number of staple crops. Food product development provides an opportunity to combine complementary raw materials in ways that improve nutrient density, diversify diets and increase the utilization of underused agricultural commodities. Plantain and Bambara groundnut are two crops with considerable potential for such utilization. Plantain provides substantial carbohydrate and starch, while Bambara groundnut is comparatively rich in protein, fat, dietary fibre and minerals. The combination of cereal-, root- or fruit-based ingredients with legumes is widely considered useful for improving the nutritional quality of food products because the ingredients can complement one another nutritionally. Bambara groundnut has particularly attracted research interest because of its nutritional density, resilience and potential contribution to food and nutrition security (Mayes et al., 2019; Olanrewaju et al., 2022). Thus, the development of snack products from plantain and Bambara groundnut flour represents an opportunity to transform locally available crops into convenient foods with potentially improved nutritional characteristics.

Plantain (Musa spp.) is an important tropical food crop that is consumed in different forms and can also be processed into flour. Plantain flour is particularly useful in food product development because drying and milling convert the highly perishable fruit into a more stable ingredient that can be incorporated into a variety of food products. The nutritional characteristics of plantain flour depend on cultivar, maturity and processing method. A Nigerian study by Okole et al. (2022) found that plantain flour samples produced through different drying and blanching methods contained relatively high carbohydrate levels, while protein and fat contents were comparatively low. Similarly, research examining plantain flour properties has shown that cultivar, maturation stage and pretreatment can significantly affect chemical composition, functional properties and starch characteristics. Unripe plantain flour is particularly relevant for product formulation because of its high starch content and functional properties, including water-holding characteristics, which can affect the texture and processing behaviour of formulated foods (Okole et al., 2022; Oyeyinka et al., 2021). Consequently, plantain flour can serve as an important carbohydrate-rich base for snack development, but its relatively limited protein contribution creates an opportunity for complementary enrichment with a protein-rich plant ingredient.

Bambara groundnut (Vigna subterranea (L.) Verdc.) is an indigenous African legume that has attracted increasing attention because of its nutritional value, adaptability and potential contribution to food security. The grain contains substantial amounts of carbohydrate and protein together with fat, dietary fibre and minerals. Maphosa, Jideani and Maphosa (2022) reported that Bambara groundnut generally contains approximately 55–70% carbohydrate, 17–25% protein, 1.4–12% fat and 5.2–6.4% dietary fibre, although composition varies according to genotype, growing conditions and other factors. Tan et al. (2022) similarly described Bambara groundnut as a protein-rich, drought-tolerant West African crop with applications in flour blends, cookies, bread and other food products. The nutritional attributes of the legume make it particularly useful for enriching foods whose principal raw material is relatively low in protein. In addition, Bambara groundnut contains important amino acids and minerals, increasing its potential value as an ingredient in nutritionally improved food products. Its incorporation into plantain-based snacks may therefore provide a means of increasing protein and other nutrient contents while simultaneously promoting the utilization of an underused African legume (Maphosa et al., 2022; Tan et al., 2022).

The nutritional complementarity between plantain and Bambara groundnut provides a strong basis for developing composite-flour snack products. Plantain flour is predominantly carbohydrate-rich, whereas Bambara groundnut contributes considerably more protein, together with fat, fibre and minerals. Research on Bambara groundnut-enriched food products has demonstrated that incorporation of Bambara groundnut flour can improve the protein content of formulated foods. Nwadi, Uchegbu and Oyeyinka (2020) reviewed the use of Bambara groundnut flour in food blends and reported that its incorporation into different food products has generally improved their protein content, although sensory challenges such as characteristic taste and flavour may arise at higher inclusion levels. Oyeyinka et al. (2018) also demonstrated that snacks produced from Bambara groundnut flour could contain appreciable protein levels, although sensory characteristics varied according to whether flour or paste was used. These findings suggest that the nutritional benefits of Bambara groundnut need to be considered alongside product formulation and consumer preference. Therefore, combining plantain and Bambara groundnut at carefully selected proportions may provide an opportunity to obtain a nutritionally enhanced snack without compromising desirable sensory characteristics (Nwadi et al., 2020; Oyeyinka et al., 2018).

Snack foods occupy an important position in contemporary diets because they provide convenient foods that can be consumed between major meals and are commonly purchased by children, adolescents and adults. However, the nutritional quality of snacks varies considerably depending on their ingredients and processing methods. The development of snacks from indigenous crops can provide alternatives to products based predominantly on imported or less locally available ingredients. Bambara groundnut has already been investigated as an ingredient for crackers, biscuits and extruded products, with research indicating that its inclusion can influence nutritional, functional and sensory properties. Mayes et al. (2019) highlighted the potential of Bambara groundnut in snack products while also noting that formulation and processing can affect product characteristics and consumer acceptance. More recently, Dzandu, Tettey and Bruce-Adjei (2024) developed doughnuts from different proportions of unripe plantain and Bambara groundnut flours and found that the formulations differed in functional and nutritional properties, while all tested doughnuts achieved generally acceptable sensory scores. These findings demonstrate the feasibility of using the two crops together in snack development and support further investigation of different product formulations and their nutritional and sensory outcomes.

Consumer acceptability is a critical consideration in the development of any new food product because a nutritionally superior product may have limited practical value if consumers are unwilling to eat it. Sensory attributes such as colour, taste, aroma, texture, crispness, appearance and overall acceptability can influence consumers’ perceptions and purchasing decisions. This is particularly important when incorporating Bambara groundnut into foods because its nutritional benefits may be accompanied by a characteristic beany flavour that can affect sensory preference. Nwadi et al. (2020) noted that some Bambara groundnut-enriched products have experienced sensory limitations, particularly in relation to taste and flavour, and identified processing approaches such as roasting, germination and extrusion as possible ways of improving sensory quality. Oyeyinka et al. (2018) similarly observed differences in sensory properties between Bambara groundnut snacks prepared from flour and paste. These observations indicate that the success of a plantain–Bambara groundnut snack should not be assessed solely on proximate composition; it should also be evaluated through sensory testing to determine whether the resulting product is acceptable to potential consumers (Nwadi et al., 2020; Oyeyinka et al., 2018).

Recent research has provided direct evidence that plantain and Bambara groundnut can be combined successfully in food product development, but further formulation studies remain necessary. Dzandu et al. (2024) evaluated doughnuts formulated with 90:10, 85:15, 80:20 and 75:25 plantain-to-Bambara-groundnut flour ratios and reported differences in nutritional and functional properties among the flour blends. Bambara groundnut flour recorded the highest protein value, while plantain flour contributed substantially to carbohydrate content. The resulting doughnuts obtained overall sensory scores ranging from 5.79 to 7.10 on the reported scale, and the authors concluded that the products were generally acceptable, with the 90:10 plantain-to-Bambara-groundnut formulation receiving the highest overall preference. However, the study focused on doughnuts produced in Ghana, demonstrating the feasibility of the combination but also leaving room for additional investigations using locally available raw materials, different snack formats and alternative formulation ratios. The present study therefore seeks to investigate the nutritional composition and consumer acceptability of snack products developed from plantain and Bambara groundnut flour, thereby contributing further evidence on the utilization of these locally important crops in food product development (Dzandu et al., 2024).

1.2 Statement of the Problem

Plantain is a nutrient-containing and widely utilized tropical crop, but the fresh fruit is highly perishable and its utilization is frequently concentrated in traditional forms of consumption. Conversion of plantain into flour provides an avenue for extending its shelf life and broadening its use in formulated foods. However, plantain flour is predominantly carbohydrate-based and contains relatively low protein compared with legumes such as Bambara groundnut. Research in Nigeria has demonstrated that plantain flour contains high levels of carbohydrate while protein levels are comparatively low, suggesting that plantain-based food products may benefit nutritionally from incorporation of protein-rich ingredients (Okole et al., 2022). At the same time, Bambara groundnut possesses considerable nutritional potential but remains underutilized in many food systems despite its relatively high protein content and favourable nutritional characteristics (Maphosa et al., 2022). The problem, therefore, is not simply the availability of these crops but the need to develop convenient and acceptable food products that effectively combine their complementary nutritional characteristics.

A further problem concerns the limited utilization of Bambara groundnut in commercially familiar snack products. Although Bambara groundnut flour has been successfully incorporated into several food products, its distinctive taste and flavour may affect consumer acceptance, especially when used at relatively high inclusion levels. Nwadi et al. (2020) identified sensory quality as one of the important limitations affecting the wider utilization of Bambara groundnut in formulated foods. Oyeyinka et al. (2018) similarly found that the sensory properties of Bambara groundnut snacks varied according to the form in which the legume was incorporated. Consequently, simply increasing the proportion of Bambara groundnut in plantain-based snacks cannot be assumed to produce a better food product. There is a need to determine formulation levels that provide meaningful nutritional enhancement while retaining desirable sensory properties. This creates a product-development problem requiring both laboratory nutritional analysis and systematic consumer sensory evaluation (Nwadi et al., 2020; Oyeyinka et al., 2018).

Another problem is the limited body of research directly examining plantain–Bambara groundnut combinations for snack development compared with the much larger literature on individual crop utilization. The recent study by Dzandu et al. (2024) demonstrated that different plantain and Bambara groundnut flour ratios produce differences in nutritional composition, functional characteristics and sensory scores of doughnuts. However, the findings were obtained from a specific doughnut formulation and production context in Ghana. Similarly, studies on Bambara groundnut snacks have established its usefulness as a protein-rich ingredient, but they have also demonstrated that processing method and formulation influence sensory characteristics (Oyeyinka et al., 2018). This indicates that additional studies are required to examine other snack products and formulation conditions. Without such evidence, it is difficult to determine which combinations of plantain and Bambara groundnut flour can provide an appropriate balance between nutritional improvement and consumer acceptance.

The central problem addressed by this study is therefore the insufficient empirical evidence on the nutritional composition and consumer acceptability of snack products developed from plantain and Bambara groundnut flour. Although existing research indicates that plantain contributes substantial carbohydrate and useful functional properties while Bambara groundnut contributes considerable protein, fibre, fat and minerals, the nutritional and sensory outcomes of their combination depend on formulation and processing conditions (Tan et al., 2022; Okole et al., 2022). Furthermore, the recent direct evidence from plantain–Bambara groundnut doughnuts demonstrates that formulation ratio can affect product characteristics and consumer ratings, but further product development and evaluation remain necessary (Dzandu et al., 2024). This study therefore seeks to formulate snack products from plantain and Bambara groundnut flour, determine their proximate nutritional composition and evaluate their sensory attributes and overall consumer acceptability. The study is expected to provide evidence that can support the development and utilization of nutritionally improved snacks based on locally available plant materials.

1.3 Purpose of the Study

The general purpose of this study is to determine the nutritional composition and consumer acceptability of snack products developed from plantain and Bambara groundnut flour.

Specifically, the study seeks to:

1. formulate snack products from different proportions of plantain and Bambara groundnut flour;
2. determine the proximate nutritional composition of the snack products developed from plantain and Bambara groundnut flour;
3. evaluate the sensory characteristics of the developed snack products in terms of colour, aroma, taste, texture and overall acceptability; and
4. determine whether significant differences exist in the consumer acceptability of the snack products produced from the different plantain and Bambara groundnut flour formulations.

1.4 Research Questions

The following research questions will guide the study:

1. What snack products can be formulated from different proportions of plantain and Bambara groundnut flour?
2. What is the proximate nutritional composition of the snack products developed from plantain and Bambara groundnut flour?
3. What are the sensory characteristics of the developed snack products in terms of colour, aroma, taste, texture and overall acceptability?
4. Is there a significant difference in the consumer acceptability of snack products produced from different plantain and Bambara groundnut flour formulations?

1.5 Research Hypothesis

The following null hypothesis will be tested at the 0.05 level of significance:

H₀: There is no significant difference in the consumer acceptability of snack products produced from different proportions of plantain and Bambara groundnut flour.

1.6 Significance of the Study

Consumers

The study will provide consumers with information concerning the nutritional characteristics and sensory acceptability of snack products developed from plantain and Bambara groundnut flour. The findings may demonstrate the potential of locally available plant-based ingredients to produce convenient snacks with improved nutritional characteristics.

Food Product Developers

The findings will be useful to food scientists, nutritionists, home economists and product developers interested in developing innovative foods from indigenous crops. The study may provide information on appropriate formulation proportions and the relationship between formulation and nutritional and sensory characteristics.

Farmers and Producers

The study may encourage increased utilization of plantain and Bambara groundnut as raw materials for food processing. Increased demand for value-added applications could create additional market opportunities for farmers producing the two crops.

Food Processing Industries

Small- and medium-scale food processors may benefit from information concerning the feasibility of incorporating plantain and Bambara groundnut flour into snack products. The findings may support the development of locally sourced alternatives to products based heavily on conventional cereal flours.

Nutritionists and Public Health Professionals

Nutritionists and public health professionals may find the results useful when considering food-based approaches to dietary diversification. Bambara groundnut is recognised as a nutrient-dense African legume containing substantial protein and minerals, while plantain contributes considerable carbohydrate and starch (Maphosa et al., 2022; Olanrewaju et al., 2022). The combination therefore provides a basis for exploring nutritionally complementary food formulations.

Researchers and Students

The study will contribute to the literature on composite flour technology, indigenous crop utilization, food product development, nutritional analysis and sensory evaluation. It may also provide a basis for further studies involving other ratios, processing techniques, snack formats, storage conditions and additional nutritional parameters.

Agricultural Development

The study may contribute indirectly to the promotion of underutilized crops by demonstrating additional food applications for Bambara groundnut and plantain. Bambara groundnut has been identified as a climate-resilient and underutilized crop with potential contributions to food and nutrition security, while product development is one route through which its utilization can be expanded (Olanrewaju et al., 2022; Soumare et al., 2022).

1.7 Scope of the Study

The study will focus on the nutritional composition and consumer acceptability of snack products developed from plantain and Bambara groundnut flour.

The content scope will cover the preparation of plantain flour, preparation of Bambara groundnut flour, formulation of composite flour at selected ratios, production of snack products, proximate nutritional analysis and sensory evaluation.

The nutritional analysis will focus principally on proximate composition, including moisture, crude protein, crude fat, crude fibre, ash and carbohydrate. Where laboratory facilities permit, additional parameters such as selected mineral contents may also be assessed.

The sensory evaluation will cover attributes such as colour, aroma, taste, texture/crispness and overall acceptability using an appropriate hedonic scale.

The study will compare snack samples produced using different proportions of plantain and Bambara groundnut flour. A control sample may consist of 100% plantain flour, while experimental samples may contain increasing proportions of Bambara groundnut flour.

The study will not primarily investigate the clinical health effects of consuming the products. Nutritional composition will be assessed through laboratory analysis, while consumer acceptability will be assessed through sensory evaluation.

1.8 Operational Definition of Terms

Bambara Groundnut: An African legume scientifically known as Vigna subterranea (L.) Verdc., valued for its protein, carbohydrate, fibre, fat and mineral contents.

Plantain: A banana cultivar group belonging to the genus Musa that is commonly consumed as a staple food and can be processed into flour.

Plantain Flour: A powdered food ingredient produced by drying and milling plantain, particularly unripe plantain, into a relatively stable flour suitable for food formulation.

Bambara Groundnut Flour: Flour produced by cleaning, processing, drying and milling Bambara groundnut seeds into a powder suitable for incorporation into food products.

Composite Flour: A flour mixture produced by combining two or more different food flours in predetermined proportions.

Snack Product: A ready-to-eat or conveniently prepared food generally consumed between main meals. In this study, it refers specifically to the products formulated from plantain and Bambara groundnut flour.

Nutritional Composition: The quantities of nutrients and proximate components present in the developed snack products, particularly moisture, protein, fat, fibre, ash and carbohydrate.

Proximate Composition: Laboratory determination of the major nutritional components of a food, commonly including moisture, crude protein, crude fat, crude fibre, ash and carbohydrate.

Consumer Acceptability: The extent to which consumers or sensory panellists like or approve of a food product based on its sensory characteristics and overall liking.

Sensory Evaluation: A systematic assessment of food products using human senses to determine characteristics such as colour, aroma, taste, texture and overall acceptability.

Formulation Ratio: The predetermined proportion of plantain flour to Bambara groundnut flour used in producing a particular snack sample.

Nutritional Enhancement: Improvement in the nutritional profile of a food product through the incorporation of an ingredient that contributes desirable nutrients.

Food Product Development: The systematic process of selecting ingredients, formulating, processing and evaluating a new or modified food product to achieve desirable nutritional, functional, sensory and safety characteristics.

Project – Nutritional Composition and Consumer Acceptability of Snack Products Developed from Plantain and Bambara Groundnut Flour