Development, Nutritional and Storage Analysis of Pearl Millet Value-added Traditional Snacks (Namakpara, Mathri) Enriched with Jamun Seed Powder

Namakpara and Mathri are popular traditional Indian snacks known for their savory taste and crunchy texture joyed during festive occasions, tea-time, or as accompaniments to meals and prepared using refined flour as the main ingredient. However, the increasing awareness about the health implications of consuming refined flour-based products has prompted researchers and food manufacturers to explore alternative and healthier ingredient options. Pearl millet, also known as Bajra in Hindi, is one of the major millet crops grown in India. Pearl millet (Pennisetum glaucum) is a nutritious and drought-resistant (Singh, 2003) cereal grain that has gained attention for its health benefits. Pearl millet is rich in dietary fiber, vitamins, minerals and bioactive compounds (Vaijapurkar et al., 2015; Kaushik and Grewal, 2017) which contribute to its antioxidant and anti-inflammatory properties. As a gluten-free grain, pearl millet is suitable for individuals with gluten sensitivity or celiac disease (Veena et al., 2004), making it an ideal choice for developing gluten-free snacks.
       
Jamun seeds (Syzygium cumini), are traditionally used for their medicinal properties (Sidana et al., 2017) and are known for their anti-diabetic, anti-inflammatory and antioxidant effects. The seeds contain chemical constituents (Raza et al., 2015) e.g. phenolic compounds (Banu and Jyothi, 2016), flavonoids and other bioactive that contribute to their therapeutic potential. Jamun, also known as the Indian Blackberry fruit, is native to India. In recent years, there has been increasing interest in utilizing pearl millet and jamun seeds for their nutritional and health benefits. Overall, the ample production of pearl millet and jamun seeds in India is promising in ensuring food security, providing nutrition, enhanced health benefits and promoting sustainable agricultural practices.
       
In this research study, we explore the potential of pearl millet-based Namakpara and Mathri snacks incorporated with jamun seeds to assess their potential as healthier alternatives. We aim to enrich these traditional snacks with essential nutrients, enhance their sensory attributes and improve their overall profile. We evaluate the changes in proximate compositions, sensory characteristics and oxidative stability during storage to understand the effects of these additions on snack quality and shelf life.

The Department of Genetics and Plant Breeding at CCS, HAU, Hisar provided the Pearl millet variety (HC 10). Fresh Jamun fruits from a nearby market were cleaned, the seeds removed and air-dried for 24 hours at 55°C. The dried seeds were sieved, crushed and kept in hygienic storage.
 
Ingredients for namakpara
 
Carom seeds (1 g), Salt (1 g), Sodium bicarbonate (1 g), Ghee (20 g), Water (60 ml), Oil for frying.
 
Ingredients for mathri
 
Black pepper powder (0.5 g), Salt (2 g), Dried fenugreek leaves (0.5 g), Sodium bicarbonate (1 g), Ghee (30 g), Water (50 ml), Oil for frying.
 
Types for namakpara and mathri
 
Control = Pearl millet flour (50 g), Refined flour (50 g).
Type I   =    Pearl millet flour (45 g), Refined flour (45 g), jamun seed powder (10 g).
Type II  =    Pearl millet flour (42.5 g), Refined flour (42.5 g), jamun seed powder (15 g).
Type III =    Pearl millet flour (40 g), Refined flour (40 g), jamun seed powder (20 g).
 
Method to develop namakpara and mathri
 
To properly combine all the ingredients mentioned for mathri and namakpara, sieved pearl millet flour, refined flour and jamun seed powder. Ghee was added and the flour mixture was carefully stirred with both hands to make a stiff dough with warm water. The dough was divided into two equal pieces and the balls were rolled each one into a thin sheet using a rolling pin. With the help of a knife, cut the sheet into shapes and deep-fried in hot oil till golden brown over low heat (Plate 1 and 2).
 

 

 
 
Sensory assessment
 
A semi-trained panel of 10 judges evaluated the snacks’ sensory quality using a 9-point hedonic scale (Peryam et al., 1957).
 
Nutritional evaluation
 
The products were dried at 60°C for analytical analysis. The standard analysis procedures were used to calculate the moisture, protein, fat, crude fiber and ash contents (AOAC, 2000). According to Lindsay and Norwell’s (1969) approach, the total mineral content was calculated. We used the modified approach to determine in vitro protein digestibility (Mertz et al., 1983) and starch digestibility was evaluated using Singh et al., (1982) methodology. Phytic acid in samples was measured using Davies and Reid’s method from 1979 and Singh and Jambunathan’s method from 1981 was used to extract the polyphenols. The shelf-life of 90 days was assessed by sensory characteristics, fat acidity and lipid oxidation (AOAC, 2000).
 
Statistic evaluation
 
According to the accepted methodology, the statistical analysis of the quality evaluation data included mean, standard deviation and ANOVA with three replications (Sheoran and Pannu, 1999) and a T-test was performed for nutritional analysis.
 
Hypothesis
 
The question is whether using jamun seed powder for pearl millet flour in snack compositions will impact the products’ nutritional value and sensory qualities. The sensory and nutritional qualities of the snacks will be the same in this scenario, H0, = 0. Another possibility is Ha: 0 and > 0 (one-tailed test); the snacks’ sensory and nutritional characteristics will be better or worse than the control. The sensory and nutritional qualities of the snacks will differ from the control, according to a two-tailed test result of 0.

Sensory analysis
 
The organoleptic (Table 1) assessment of Namakpara and Mathri, incorporating jamun seeds, power highlighted their sensitivity to seed levels. Lower jamun seed amounts preserved sensory acceptability, but higher levels negatively impacted color, appearance, texture, taste and overall acceptability. Control Namakpara, made with pearl millet and refined flour, scored 7.90 for color and appearance, 7.60 for aroma, 7.70 for texture, 7.70 for taste and 7.76 overall. Type I Namakpara with jamun seeds was ‘liked moderately,’ while Type II and III were ‘liked slightly.’ Mathri remained organoleptically acceptable up to 10% jamun seed incorporation, with Type III falling into the “Neither like nor dislike” category. Control mathri scored 7.80 for color and appearance, 7.40 for taste, 7.70 for texture, 7.90 for taste and 7.72 overall, placing them in the ‘liked moderately” group. The study emphasizes the delicate balance in incorporating jamun seeds for optimal sensory appeal in these snacks. The sensory results are supported by Yadav and Yadav (2020) who developed namakapara, sev, mathri with a gluten-free flour mix. Tripathi et al., (2017) stated that malted nutria flour and leaf powder mix could be used up to 20% without affecting the sensory score. Developed mathri with cress garden seed up to 15% was rated desirable for color, appearance, flavor, texture, taste and overall acceptability (Rana and Kaur 2016). Savita et al., (2023) found similar sensory results in biscuits, chapati, dalia and upma developed with a 20% incorporation of pearl millet and jamun seed powder and pearl millets flour. Similar sensory score results were reported by Savita et al., (2024) that the incorporation of jamun seed powder decreased the sensory score in pasta and noodles.  The added Jamun seed powder to pearl millet-based snacks may deepen the color due to its polyphenolic content, potentially influencing sensory traits.
 

 
Nutritional analysis
 
The nutrient profile (Table 2) of the snacks was influenced by the jamun seed power incorporation, leading to changes in protein (8.84 to 7.34%), fat (28.63 to 23.01%), ash (2.12 to 2.77%), crude fiber (1.07 to 1.51%), calcium (28.82 to 47.47 mg/100 gm), phosphorus (132.43 to 152.53 mg/100 gm), zinc (1.95 to 2.60 mg/100gm), phytic acid (382.23 to 405.23 mg/100 gm) and polyphenols (258.13 to 272.55 mg/100 gm) content. The decrease in crude protein (7.95%, 7.34%) and fat (23.10%, 26.21%) content in Type I samples may be attributed to the substitution effect of jamun seeds, which have a lower protein (8.84%, 8.52%) and fat (25.10%, 28.63%) content compared to the control namakpara and mathri respectively. Conversely, the increase in ash (2.48%, 2.77%) and crude fiber (1.51%, 1.45%) content in Type I samples (namakpara and mathri) could be due to the mineral and fiber-rich nature of jamun seeds. The significant increase in calcium (44.36 and 47.47 mg/100 gm) and zinc (2.53 and 2.60 mg/100 gm) content in Type I samples (namakpara and mathri) highlights the potential of jamun seeds as a source of essential minerals in traditional snacks. However, the decrease in phosphorus (152.53 to 132.43 m g/100 gm) content warrants investigation to further understand the interplay of ingredients affecting phosphorus availability. The in-vitro studies indicated that jamun seed incorporation led to a reduction in protein digestibility (65.74 to 51.47%) and starch digestibility (29.30 to 31.50 mg maltose released/gm) was not affected by jamun seed powder incorporations. The phytic acid (405.23 to 382.23 mg/100 gm) content decreased in formulated products which is a desirable outcome as phytic acid can interfere with mineral absorption. The increase in polyphenols (258.13 to 272.55 mg/100gm) content suggests the potential for jamun seeds to contribute to the antioxidant content of the snacks. Results align with Singh (2003) on moisture in sev and matar. Type I treatments showed significantly lower protein than controls. Fat in control was slightly lower, the ash content in sev matched and crude fiber values were lower than Singh’s for sev and matar. Calcium content was quite similar and higher phosphorus in Singh’s study could stem from pearl millet variations. Namakpara starch digestibility was lower and sev in-vitro protein digestibility matched Singh’s values (2003). Present results supported by Rana and Kaur (2016) that mathri developed with garden cress seeds (15%level) decrease protein, fat and moisture content. Mehra and Singh (2017) reported that pearl millet incorporation in mathri increases the nutrient content than cereal-based mathri. Kadbhane et al., (2019) experiment shows that tandulaja leaf powder (7 gm) in mathri increases nutrient content such as protein (11.5gm), fat (24.45%) and ash (2.5 gm). Savita et al., (2023) developed biscuits and Indian breakfast items (chapati, dalia, upma) with jamun seed powder, assessing their nutritional profile. Nutritional composition such as crude fiber, calcium, iron, zinc and  polyphenols content increased while protein, fat, phosphorus and phytic acid content significantly decreased when 10% jamun seed powder was added. The incorporation of Jamun seed powder into pasta and noodles significantly enhanced their nutritional profile by increasing protein, ash, calcium, iron, zinc, phytic acids and polyphenols, without affecting moisture, fat, fiber, magnesium, protein, or starch digestibility (Savita et al., 2024). This suggests Jamun seed powder can be a valuable ingredient for improving the nutritional value of these food products. Control products exhibited similar or better results compared to other samples in terms of moisture, fat, fiber, magnesium, protein and starch digestibility. However, the incorporation of Jamun seed powder in snacks made from pearl millets offers the additional advantage of enriching the product with essential minerals, antioxidants and bioactive compounds like phytic acids and polyphenols, thereby potentially enhancing its nutritional value and health benefits. Some recommend limiting phytate intake to 100-400 mg/day, especially if you have digestive issues, mineral deficiencies, or body pain. To minimize micronutrient loss, it is advised to consume less than 25 mg of phytic acid per 100 g of food, as it can inhibit mineral absorption. Typical Western diets contain 250-800 mg of phytate daily, with vegetarian and Mediterranean diets potentially reaching up to 1 gram, while some European/American diets may provide up to 2 grams. (Buades Fuster et al., 2017).  Additionally, Jamun seed powder could introduce a unique flavor profile and contribute to the diversification of snack options, catering to consumer preferences for healthier and more nutrient-dense choices.
 

 
Storage study
 
Table 3 highlights the diverse impacts of incorporating pearl millet-based jamun seed powder on the organoleptic scores of Namakpara and Mathri during storage. Type I samples exhibited better retention of sensory attributes than controls, particularly in color, appearance, texture, taste and overall acceptability. Enhanced scores suggest jamun seed incorporation improves the snacks’ long-term sensory appear. Aroma, however, showed minimal changes during storage. Overall acceptability scores of Type I samples remained comparable to controls initially, but after 30 days, Mathri control scores decreased while Type I scores held steady. At 60 and 90 days, both Namakpara and Mathri control scores dropped further, with Type I samples retaining better scores, notably significant for Mathri at 60 and 90 days. Table 4 highlights the impact of jamun seed incorporation on lipid quality and oxidative stability during storage. Type I samples showed a significant decrease in fat acidity and peroxide value, indicating potential antioxidant properties, mitigating lipid oxidation and improving snack shelf life and quality. Notably, Singh (2003) reported a significant reduction in overall acceptability scores of matar during storage, emphasizing the importance of ingredient ratios in maintaining acceptability over time. Ahlawat and Jood (2011) stated that the increase in fat acidity could be attributed to the hydrolysis of triglycerides resulting in the formation of free fatty acids with an increased storage period. Possibly, the increment was due to the oxidation of polyunsaturated fatty acids which lead to rancidity and off-flavor development. Savita et al., (2023) stated that the incorporation of jamun seed powder in pearl millet for the development of biscuits increased the shelf life of stored products. Savita et al., (2024) reported that incorporating Jamun seed powder into pasta and noodles increases their shelf life during storage periods (90 days). Pearl millet, while rich in nutrients, poses challenges due to its anti-nutrient content, which lowers nutrient bioavailability and necessitates strategies to manage bitterness and rancidity (Nantanga et al., 2008). Enzymatic breakdown during storage can lead to an increase in product fatty acids and peroxide value over time (Chaiyasit et al., 2007; Yadav et al., 2014). Moreover, light exposure accelerates oxidation while fat acidity, influenced by moisture and lipolysis, tends to rise during storage and is associated with bitterness (Nantanga et al., 2008). Overall, the findings from this study demonstrate the potential of pearl millet-based jamun seed incorporation in improving the lipid quality and oxidative stability of traditional snacks during storage.
 

 

The present study revealed that incorporating up to 10% jamun seed powder optimally enhances the nutritional profile without significantly affecting sensory scores. This enrichment increased protein, ash, calcium, iron, zinc, phytic acids and polyphenols while maintaining moisture, fat, fiber, magnesium, protein and starch digestibility. Storage studies indicated that jamun seed powder incorporation also extended the shelf life of these products. Leveraging jamun seeds’ nutritional potential allows the food industry to promote healthier snacking options and meet the growing demand for nutritious and palatable foods. Overall, the findings from this study offer valuable information for snack manufacturers and food technologists in developing healthier and more nutritious snacks without compromising on sensory quality. However, finding the right balance between nutritional enhancements and maintaining sensory is essential for successful product development.