Influence of Education on the Sustainability of Melon Seed Snacks (Robo) Enriched with Sweet Potato in Ilorin, Nigeria

Materials and methods

Sample collections included melon seeds and sweet potato samples obtained from Ipata Market in Ilorin, Kwara State, Nigeria, along with common ingredients such as salt, onion, and pepper. Analyses were conducted on processed samples to determine the proximate composition of melon seed snacks, including moisture, ash, crude protein, fat, fiber, and carbohydrates, using Cunniff P [10] methods. All reagents used were of food and analytical grade.

Processing of sweet potato

Figure 1 describes the sequential process for the production of sweet potato flour (Ipomoea batatas). The process begins with the Washing of the harvested tubers to remove external debris. It was peeled to remove the skin, and then slicing the tubers into uniform pieces. The sliced potato underwent a blanching stage before drying. The dried slices are then subjected to Milling to reduce particle size. The resulting product is refined through sieving to ensure uniform particle size before the final stages of packaging and storage.

Figure 1: Sweet Potato Flour Production Flow.

Figure 2 shows the complete, multi-stage production process for the sweet potato-enriched melon seed snack. The flow was segmented into three primary phases: Melon Seed Preparation, Sweet Potato Flour Preparation, and Final Snack Formulation.

Figure 2: Sweet Potato Flour Production Flow.

Phase 1: Melon Seed Preparation (Traditional Robo Base).

The process starts with the initial preparation of the melon seeds through shelling and drying. The dried seeds are then subjected to roasting for a duration of 15 minutes. The roasted seeds are subsequently blended into a paste. This paste is then mixed with seasoning agents, specifically salt, ground dry pepper, and onion leaves. To reduce fat content, the resulting mash undergoes defatting via kneading with 200 ml of hot water for 30 minutes. The extracted oil is then collected and stored for later use in the frying stage.

Phase 2: Sweet Potato Flour Preparation.

This phase runs in parallel, beginning with the peeling and slicing of the sweet potatoes. The slices are then immediately blanched before being subjected to drying. The dried slices are subsequently ground into flour and then Sieved (implied in the previous figure’s description) to ensure uniformity.

Phase 3: Final Snack Formulation and Finishing.

The enhancement step involves substituting defatted melon flour with specific portions of the newly prepared sweet potato flour, testing ratios of 5%, 10%, 20%, 30%, and 50%. This combined dry material is then mixed and kneaded into a cohesive, cake-like mass. The mass is then manually molded into ball shapes. These balls are then fried in the extracted oil for approximately 10 minutes until they achieve a brown, hard consistency. The finished snacks are removed and allowed to cool. The process concludes with packaging in airtight containers and subsequent Storage.

Sample Preparation and Experimental Design: The Robo snack was formulated using a combination of melon seed paste and sweet potato flour at varying substitution levels to assess their impact on nutritional and sensory quality. The substitution levels of sweet potato flour were set at 5%, 10%, 20%, and 50%, with a control sample (0%) containing 100% melon seed flour for comparison.

Sample formulation: The mixing ratios of melon seed flour and sweet potato flour for the Robo snacks are provided in the table below (Table 1).

The data were analyzed with descriptive statistics, while comparisons between samples and treatments were conducted using ANOVA with a significance level of p ≤ 0.05.

Proximate analysis

The proximate composition of the melon seed snacks was analyzed for moisture, ash, crude protein, crude fat, crude fiber, and carbohydrates by difference using the Cunniff P [10] method: Moisture Content: Determined through oven drying, with initial and final weights recorded.

Ash content: Measured by igniting the sample in a muffle furnace and assessing residual ash. Crude Protein: Measured using the Kjeldahl method, converting nitrogen content to protein percentage. Crude Fat: Extracted with a Soxhlet apparatus and n-hexane, with percentages calculated from weight difference.

Crude fiber: Determined by boiling the sample with acid and alkali, then weighing the residue after ashing. Carbohydrate Content: Calculated by subtracting the sum of moisture, ash, crude fiber, crude protein, and crude fat from 100%.

Results

The analysis of melon seed snack samples reveals diverse nutritional attributes, including moisture, ash, fiber, fat, protein, and carbohydrate (CHO) content, with statistical significance indicated by different superscripts (p < 0.05). The moisture content varied notably, with Sample M (100% melon seed) having the lowest at 6.60%, which enhances shelf stability, while Sample MSP2 (90% melon seed, 10% sweet potato) had the highest at 8.24%. Other samples ranged from 6.68% to 7.99%. Fat content was highest in Sample M at 36.13%, providing a rich flavor profile, whereas Sample MSP4 had the lowest fat content at 23.67%. The remaining samples had fat levels between 25.68% and 32.48%. Fiber content also varied, with Sample MSP2 leading at 5.96%, which promotes digestive health, while MSP5 recorded the lowest at 4.29%. Other samples ranged from 4.57% to 5.73%. Ash content, indicative of mineral presence, ranged from 3.34% (MSP5) to 5.80% (Sample M), highlighting diverse mineral profiles that may attract consumers. Sample M excelled in protein content at 38.83%, making it ideal for those seeking high-protein snacks, while Sample MSP4 had the lowest protein content at 28.12%. Protein levels in other samples varied between 29.93% and 36.49%. Carbohydrate content also showed significant differences, with Sample M at 6.90% (suitable for low-carb diets) and Sample MSP4 at 33.22% (a good energy source). Other samples ranged from 12.26% to 28.85%, catering to various dietary needs. Overall, this analysis emphasizes the nutritional versatility of melon seed snacks, enabling manufacturers to develop products that meet diverse consumer preferences and health goals (Table 2).

Sensory evaluation of melon seed snacks made from blends of melon seed and sweet potato

The table summarizes the sensory evaluation of Melon seed snacks based on five attributes: appearance, texture, flavor, taste, and overall acceptability. Higher scores indicate better quality (p < 0.05). Sample MSP5 (50:50% Melon Seed Sweet Potato) had the best appearance score of 7.54, while MSP1 (95:5%) had the lowest at 7.08. For texture, MSP3 (80:20%) scored highest at 7.36, with MSP1 at 6.84. In terms of flavor, MSP2 led with 7.40, while MSP1 had the lowest score at 6.98. For taste, MSP5 scored 7.46, significantly higher than other samples, with MSP2 and MSP4 at 7.04. Overall acceptability was highest for MSP5 at 7.76, compared to MSP1 at 7.18 and other samples: M (7.30), MSP2 (7.44), MSP3 (7.40), and MSP4 (7.42) (Table 3).

Educational intervention

The target group was the traditional Robo producer in Ilorin metropolis. In the experimental group employing the traditional method for preparing Robo, baseline assessments indicated a generally modest understanding of nutritional sustainability. Pretesting of 20 students revealed that a substantial proportion scored below 50%, with limited awareness of how conventional processing techniques, such as roasting, grinding, seasoning, and frying of melon seeds, might influence the overall nutritional quality and longevity of viability of the snack. The findings underscore the necessity for targeted educational interventions to enhance understanding and promote sustainable practices in local food production.

Pre intervention assessment

The scores were moderate, suggesting participants found the product somewhat acceptable but not particularly appealing. Color: 5.2 ± 1.1, Aroma: 4.8 ± 1.3, Taste: 5.0 ± 1.2, Texture: 4.7 ± 1.4, and Overall Acceptability: 5.1 ± 1.2. Texture and Aroma were the lowest-rated attributes, indicating areas most in need of improvement.

Post intervention assessment

After the intervention, all attributes scored above 7, moving into the “like moderately” to “like very much” range. This shows a substantial improvement in the product’s sensory qualities. Color: 7.4 ± 0.8, Aroma: 7.1 ± 0.9, Taste: 7.3 ± 0.7, Texture: 7.0 ± 0.9, and Overall and Acceptability: 7.2 ± 0.8.

Educational intervention design and assessment

The study’s core hypothesis posits that education is a critical determinant of the sustainability and market acceptance of fortified traditional foods. Therefore, a formalized educational protocol was incorporated into the research design to test this relationship rigorously. This intervention was systematically structured to elevate the technical capacity of producers and the nutritional literacy of consumers.

Procedure structure and delivery

The educational section was conducted for four weeks, comprising four discrete, two-hour instructional sessions administered at weekly intervals. The instructional approach blended theoretical instruction with practical, demonstrative learning to ensure effective knowledge transfer.

Measuring educational impact: The value of the intervention was measured using a pre- and post-test assessment model applied to all participant cohorts.

Cognitive gain assessment: A validated, 15-item questionnaire was deployed before the first session (baseline pre-test) and immediately following the final session (post-test). The instrument measured knowledge acquisition in areas such as food safety, awareness of Vitamin A deficiency, and the specific nutritional characteristics of the sweet potato. The net gain in percentage score served as the definitive metric for measuring cognitive improvement.

Sustainability outcome metrics: The long-term impact on product sustainability was subsequently assessed by integrating the following empirical outcomes:

Consumer behavioral shift: Evidenced by the post-intervention sensory evaluation results (e.g., the significant improvement in acceptability, and the articulated willingness-to-purchase.

Producer practice adoption: Documented through observational data regarding adherence to the newly trained hygiene standards and the sustained implementation of optimized packaging techniques in routine production.

Discussion of findings

The tables provided details the proximate composition of the formulated Robo, Sample MSP5 (50:50% Melon Seed and sweet potato) received the highest score for appearance, with a mean value of 7.54. Conversely, Sample MSP2 (95:5% Melon Seed and sweet potato) was favoured for both texture and flavour, achieving mean scores of 7.36 and 7.40, respectively. According to Banureka and Mahendran, taste is the primary determinant of product acceptability. Although there were no significant differences in taste among the samples (p ≤ 0.05), Sample MSP5 (Melon Seed and sweet potato), containing 50% sweet potato flour, had the highest mean taste score of 7.46. Furthermore, Sample MSP5 also attained the highest overall acceptance rating. These findings indicate that the sensory attributes of melon seed and sweet potato Robo are comparable to 100% Robo in terms of appearance, flavour, taste, texture, and overall acceptability, with the Robo sample containing 50% sweet potato being the most preferred samples, including the parameters of moisture, ash, fiber, fat, protein, and carbohydrate (CHO) content, with mean values and standard deviations. Statistical significance is denoted by different superscripts within the same column (p < 0.05).

Moisture content ranged from 6.608.24% to 8.24%, showing significant variation among the samples. Sample MSP2 (95:5% Melon Seed and sweet potato) had the highest moisture content at 8.24%, while sample M contained the least moisture at 6.60%. There was a general increase in the moisture content of the Robo samples that contained sweet potato. The moisture content of food is one of the most important and widely used indicators for assessing the quality of dried processed foods. It measures yield and the amount of food solids and can directly indicate economic value, stability, and quality. The variation in moisture content among the samples suggests differences in shelf stability, as higher moisture levels could be associated with spoilage caused by microorganisms.

The fat content in the Robo samples varied from 23.67% in Sample MSP4 (composed of 70% Melon Seed and 30% sweet potato) to 36.13% in Sample M (100% Melon Seed). The data indicate that as the proportion of Melon Seed decreased and sweet potato increased, the fat levels tended to decline. This suggests that the addition of sweet potato contributed to a reduction in the fat content of the Robo samples. These findings are consistent with those of Salami, et al. [12], who studied Robo enriched with orange-fleshed sweet potato. Similarly, Adeyeye, et al. [12] reported comparable fat content values in Robo made from melon and watermelon seeds.

Fat is essential for synthesizing steroids and hormones in the body, serving as a critical solvent for these bioactive compounds. Furthermore, fat acts as a reservoir for essential fatty acids and plays an important role in transporting fat-soluble vitamins, including A, D, E, and K. Additionally, fat is the most calorie-dense macronutrient, providing about 9 calories per gram, which is higher than that of protein and carbohydrates.

The fiber content across the Robo samples ranged from 4.29% to 5.96%. Notably, Sample MSP1 (95% Melon Seed and 5% sweet potato) exhibited the highest fiber content at 5.96%, while Sample MSP5 (50% Melon Seed and 50% sweet potato) had the lowest at 4.29%, suggesting that the latter contained relatively less dietary fiber. The results highlighted a significant decrease in fiber content with the increasing substitution of sweet potato flour. These results were higher than the 3.19% fiber content reported in melon-based Robo enriched with orange-fleshed sweet potato, although similar values (5.97% - 6.31%) were found in Robo made from melon and watermelon seeds according to Adeyeye, et al. [2]. Crude fiber is beneficial for human digestion [13], and according to Lattimer and Haub [14], there is a correlation between fiber intake and a reduced risk of coronary heart disease and certain cancers.

In terms of protein content, Sample M (100% Melon Seed) had the highest level at 38.83%, while Sample MSP4 (70% Melon Seed and 30% sweet potato) recorded the lowest at 28.12%. Similar to the trend observed in fat content, protein levels declined as the proportion of Melon Seed was reduced and sweet potato content increased. This indicates that incorporating sweet potato resulted in lower protein content in the Robo samples. The protein content was slightly lower than the 40.30% noted by Osuolale and Olayiwoola [15] in Robo produced with pepper and 41% in Robo made without pepper. However, the protein values were marginally higher than those reported by Salami, et al. [11], which ranged from 29.72% to 32.41% for Robo enriched with orange-fleshed sweet potato, and from 30.18% to 30.90% for Robo derived from watermelon and melon seeds as outlined by Adeyeye, et al. [2].

The 100% Melon Robo (sample M) showed the highest level of ash content at 5.08%, while Sample MSP5, which is a 50:50 mix of Melon Seed and sweet potato, had the lowest ash content at 3.34%. This finding suggests that when the amount of sweet potato is increased in these blends, the ash levels significantly decrease. The ash content can provide valuable information regarding the mineral quality of the biscuits. The lower ash levels found in the Robo biscuits containing sweet potato might indicate a decrease in the micronutrient quality of these blends.

This observation contrasts with research by Salami, et al. [11], which found that the ash content increased with a higher proportion of sweet potato flour in the blends. Kiin-Kabari, et al. [16] explained that the ash content in food items represents their total mineral composition, as it consists of the inorganic residue left after moisture and organic components are removed through heat treatment.

From a nutritional standpoint, ash contributes to the metabolism of other organic substances, such as fats and glucose. In a study by Ojinnaka and Agubolum [17] on the nutritional and sensory characteristics of cookies made from cashew nut and wheat, the analysis revealed protein content ranging from 7.76% to 11.84%, moisture content from 3.11% to 5.13%, fat content from 16.41% to 44.34%, crude fiber from 0.46% to 1.24%, ash content from 1.82% to 5.95%, and carbohydrate content from 34.30% to 68.00%. Consequently, a decrease in ash content could signal a reduction in mineral content.

Sample MSP (50:50% Melon Seed and sweet potato) had the highest carbohydrate content of 33.22%, while the control, sample M, had the lowest carbohydrate content at 6.90%. The results showed that incorporating sweet potato flour significantly increased the carbohydrate content of the formulated Robo. The higher carbohydrate levels in the Robo made with blends of sweet potato flour suggest that sweet potato may contain higher levels of carbohydrates. Carbohydrates serve as a source of energy and warmth for various bodily functions. If they are insufficient, the body might need to use protein and body fat to generate the necessary energy. This can potentially lead to the depletion of body tissues, as noted by Kure, et al. [18]. Therefore, the increased carbohydrate content of the Robo is an advantage, as it provides the body with energy needed for metabolic and catabolic activities. Overall, the proximate composition analysis offered valuable insights into the nutritional makeup of the Robo samples. The variations in macronutrient content among the samples highlight the potential to formulate Robo with specific nutritional attributes by adjusting the proportions of melon seed and sweet potato flour in the blend. These findings enhance the understanding of the nutritional qualities of the Robo samples, which may be important for food product development and dietary planning.

The analysis of the sensory evaluation parameters revealed no significant differences in preferences for the Robo samples. Among the various samples, the Robo made from melon seed and sweet potato flour blends demonstrated notable preferences.

Conclusion

The sensory evaluation revealed that the intervention led to marked improvements across all sensory attributes. Participants responded more positively to the color, aroma, taste, texture, and overall acceptability after changes were implemented. This suggests that the intervention was effective and significantly enhanced the consumer acceptability of the product.

Recommendations

Based on the findings, it was recommended that consumers should use a 50:50 blend of melon seed and sweet potato flour for the best taste and quality. Additionally, more snack varieties should be created using different flour combinations to reach a wider audience. Further research is needed on the shelf life of both Robo and potato, as well as gathering more consumer feedback to enhance the product in the Ilorin metropolis.