INTRODUCTIONLifestyle changes and dietary habits of human allover the world may affect nutrient intake. Therefore, ahealthy and balanced diet is important to meet the basicneeds of human body. Accordingly, nutrition bars/cerealbars are the most sophisticated ready-to-eat products dueto the natural ingredients and health concerns [1].Nowadays, a special attention has been given to byproductsto utilize raw materials as much as practicaland avoid economic losses and environmental pollution.Nutrition or energy bars are getting popular amonghealth aware consumers, school goers, and weightwatchers [2] due to its nutritive value and easy-to-use.The increasing demand of consumers for nutritioussnacks, results the fastest outgrowth in cereal barsmarket more than 20% per year [3] that provide nutritionand convenience [4].Health-conscious consumers prefer nutritious foodsto conventional sweets. This tendency driven to thedevelopment of several ready-to-eat, nutritious, andenergy bars containing different fruits and nuts [5–6].Incorporation of fruit and vegetable by-products innutrition bars not only adds the value to products butalso contributes to newly formulated food products andminimize losses of raw materials by utilizing peels,seeds, etc. [7].Modern consumers prefer snacks not only tosatisfy their hunger but also to provide themselves withessential nutrients. In this regard, food scientists todayare aiming to develop formulations of cereal bars withvarious highly nutritious ingredients. Thus, Russianscientists have developed a cereal bar with rolled oatflakes, bee honey, walnut, dried cranberry, sunflowerseeds, peanut butter, dates, and prunes [8].Snacks satisfy hunger, replace a meal, and providethe body with essential nutrition, including protein,carbohydrates, fats, and vitamins [9–10]. One of thepopular fruits in Bangladesh is banana [11], which is arich source of energy (90 kcal/100 g) [12]. In addition,banana contains health benefiting antioxidants, crudefiber, and minerals [13]. Health beneficiary effect ofbanana pulp is due to bioactive compounds [14] suchas phenolic acid compounds, flavonoids, carotenoids,sterols, and antimicrobial compounds. The compoundsmake banana a perfect functional food [15].Russian researchers revealed that main sources ofvegetable protein are seeds of legumes and oilseeds [16].Pumpkin (Cucurbita pepo L.) seed has also receivedconsiderable attention due to its nutritional value(200 calories) and high content of amino acids, such aspalmitic, oleic, linoleic, and stearic, as well as dietaryfiber [17]. Pumpkin seed also shows pharmacologicalactivities including anti-fungal [18], anti-cancer [19],anti-bacterial, anti-inflammation, and anti-oxidanteffects [20]. The robust flavor of pumpkin seed allowsusing it as a valuable ingredient in cooking [21].Pumpkin seed oil obstructs changes in plasma lipidsand blood pressure together with inadequate estrogenavailability [22].Recent research on pumpkin seed flour indicatedthat it increased reducing sugars, vitamin C, andcarotenoid content in bread [23]. 10% of pumpkinseed flower in a cake formulation had strong effectson physicochemical and organoleptic properties of thecake [24]. Replacement of refined wheat flower withpumpkin seed flower improved the textural and sensoryqualities of cookies [25]. Addition of 15% of pumpkinseed flower into biscuit dough had a significant effect onthe rheological and sensory characteristics of the finalproduct [26].Searching safe methods to extend the shelf life offood products is a relevant task for the food industry.Banana and pumpkin seed demonstrate significantanti-oxidant properties. Natural antioxidants can be analternative to existing preservatives due to its abilityto inhibit oxidation of the main nutrients [27]. Anincreasing growth of metabolic diseases and obesityworldwide is a global problem that makes food scientistsand researchers develop not only tasty but also healthbeneficial snacks.In Bangladesh, mango or peanut bars with glucosesyrup are popular among the population, however, theirnutritional value is low and energy value is high. Wedid not find research on the quality of bars enrichedwith pumpkin seed flour. The findings of this work willbe beneficial for the local food industry and will reducemalnutrition problems.Our work aimed to formulate bars with banana flourand pumpkin seed flour and evaluate their nutritional,textural, and sensory quality.STUDY OBJECTS AND METHODSOur research featured nutritional bars with bananaflour, pumpkin seed flour, and the mix of banana andpumpkin seed flours.Materials. Raw materials, such as brown sugar,sunflower oil, oats, corn flakes, chickpea, nuts, andraisins, were purchased from the local supermarket.All the ingredients were purchased evaluated for safetystandards. The following technical and food safetyinformation was evaluated: name of the productswith batch number, physicochemical composition,information about recognized food allergens, sensoryproperties (appearance, flavor, and aroma), microbialinformation, and shelf life. To store the ingredients,we used high-density polyethylene and low-densitypolyethylene as a packaging material.Pumpkin seed flour preparation. Pumpkin seedwas collected from the local market as a by-product ofpumpkin processing. Seeds were cleaned with potablewater and sun dried to remove extra water from thesurface of the seeds. After that, the pumpkin seed withshell was dried in a cabinet dryer (M-1816, ModernLaboratory Equipment, USA) at 55°C for 4 h, groundusing a grinder (Panasonic Mixer Grinder MX-AC555,India), and finally sieved through 20 mesh (0.841 mm)to get fine pumpkin seed flour. Then the pumpkin seedflour was weighed and vacuum packed for further use.Banana flour preparation. Ripe banana (Sagorvariety) was collected from the Horticulture centerof Bangladesh Agricultural University, Bangladesh.Banana was sorted to remove defected banana andwashed with running water. Banana was sliced into0.5 cm thick pieces with peel. To reduce enzymaticbrowning, the slices were then dipped in 10% citric acidsolution for 10 min. The peel was removed and slicedbanana was air dried to remove extra water. Bananathen was dried in a cabinet dryer (M-1816, ModernLaboratory Equipment, USA) at 60°C for 5 h, groundusing a grinder (Panasonic Mixer Grinder MX-AC555,India), and sieved through 30 mesh (0.595 mm) to getfine flour. The banana flour was vacuum packed forfurther use.Bar preparation. Three nutrition bars wereformulated: with banana flour, with pumpkin seed flour,and with the mixed flours (Table 1). Amounts of bananaflour, pumpkin seed flour, salt, and lecithin were chosenbased on trial and error methods to find the optimumcolor and texture of the bars. Similarly, the otheringredients were chosen based on consumer interest bysurvey (data not shown).Figure 1 demonstrates the production process ofnutrition bars. At first, all the dry ingredients, suchas oats, corn flakes, pumpkin seed flour and/or bananaflour, nuts, raisins, chickpea, and skim milk powder,were weighed and mixed gently. The heated sugar syrup,sunflower oil, and lecithin were added into the drymixture and mixed. The mixture was heated in a waterbath at 70°C. The mixture then was compressed, driedin an oven at 110°C for 15 min, and cut into uniformpieces (12×2.5×2.0 cm) and cooled at room temperature(25°C) for 30 min. The bars were packed in low and highdensity package and then kept in a sealed container atambient temperature for further analysis.284Habiba U. et al. Foods and Raw Materials, 2021, vol. 9, no. 2, pp. 282–289The proximate analysis of pumpkin seedflour, banana flour and newly formulated bars weredetermined by Tasnim et al. [28] using the guidelinesand methods of AOAC (Association of OfficialAnalytical Chemists): moisture content ‒ method 950.46;crude protein, 981.10; crude fat, 922.06; crude fiber,978.10; and ash, 920153.00. Total carbohydrate contentsin the both flours and nutrition bar were estimatedaccording to the methods of Food and AgricultureOrganization (FAO) [29]. Mineral contents weredetermined following the procedures described in [30].Inductively coupled plasma emission spectrophotometerwas used to analyze calcium, iron, magnesium,phosphorus, and potassium in the samples.The antioxidant activities of flours and nutritionbars were determined by using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging modifiedmethod, as described by Brand-Williams et al. [31].In methanol, DPPH in oxidized form gives a deepviolet color. However, antioxidant compounds usuallydenote an electron to DPPH, thus causing reduction. Inreduction form, DPPH turns to yellow. A 0.002% DPPHsolution was prepared in methanol and measured at517 nm. Sample extracts (50 μL) were mixed with 3 mLof the DPPH solution and kept for 15 min in the dark.Then the absorbance was measured again at 517 nm.The total phenolic content in the banana flour,pumpkin seed flour, and nutrition bar was determinedusing the modified method of Odabasoglu et al. [32].The total phenolic content of the samples was calculatedas gallic acid equivalents (mg GAE/g) and everyexperiment was performed in triplicate. Peroxidevalue, free fatty acids, and thiobarbuturic acid (MA/kgsample), which are generally used to evaluate lipidoxidation in food products, were measured inaccordance with Rukunudin et al., Sallam et al. andSchmedes and Holmer, respectively [33–35].The color characteristics of the nutrition bar weredetermined using a Minolta colorimeter (Cr-400/410,Japan). The CIELB scale with L*, a* and b* was usedto analyze the results, where L* showed the lightness(L* = 0, black and L* = 100, white) of the product,a* showed red-green color (+60 to –60), and b* showedyellow-blue color (+60 to –60) [36].The textural parameters of the nutrition bar underthe study (12×2.5×2.0 cm) were determined using atexture analyzer (Stable Micro Systems, UK) and themodified method described by Momin et al. [37]. Thecutting probe and compression platen of the textureTable 1 Formulation of nutrition bars with banana flour,pumpkin seed flour, and mixed flour, g/100 gIngredient BananaflourPumpkinseed flourMixedflourOats 10 10 10Corn flakes 10 10 10Pumpkin seed flour 0 15 10Banana flour 15 0 5Sunflower oil 10 10 10Nuts 7 7 7Raisins 6 6 6Water 6 6 6Salt 0.2 0.2 0.2Lecithin 0.8 0.8 0.8Glucose syrup 10 10 10Brown sugar 10 10 10Chickpea 5 5 5Skim milk powder 10 10 10Figure 1 Flowchart of nutrition bars production processHeating in a water bath (70°C)PressingDrying in an oven (110°C, 15 min)Cutting (12×2.5×2.0 cm)Cooling (room temperature, 30 min)PackagingOats, corn flakes, pumpkin seed flourand/or banana flour, nuts, raisins,Chickpea, skim milk powderSunflower oil, salt, brown sugar,lecit hin, glucose syrupDry ingredients Aglutina te syrup285Habiba U. et al. Foods and Raw Materials, 2021, vol. 9, no. 2, pp. 282–289analyzer were calibrated at a 20 cm distance using dataacquisition software. The following parameters wereused for the analysis: pre-test speed 1.0 mm/s, trigger5 g, and post-test speed 10 mm/s. Each sample wastexted in three replications.Three different types of the nutrition bars wereevaluated by 10 semi-trained panelists for color, flavor,texture, and overall acceptability. For statistical analysis,the 9-point hedonic rating test [38] was used to accessthe sensory quality of the newly nutrition bar. Theanalysis was performed three times. The significantdifference of mean values was assessed by the analysisof variance (ANOVA) using a software STATISTICversion 8.1. For the significant difference, DMRT wasapplied.RESULTS AND DISCUSSIONTable 2 shows the nutrient composition of pumpkinseed flour and banana flour. It is remarkable that thepumpkin seed flour contained significantly (P < 0.5)higher amount of protein and fat but lower amount ofwater, crude fiber, and carbohydrate, compared to thebanana flour. Among the minerals, calcium, magnesium,and phosphorus concentrations were higher in thepumpkin seed flour and iron and potassium was higherin the banana flour (Table 2). The energy value of thepumpkin seed flour (604.44 kcal/100 g) was also higherthan that of the banana flour (385 kcal/100 g).The nutrition bars developed (Fig. 2) were analyzedto determine their nutritional value (Table 3). Dietaryprotein is one of the vital nutrients for human due toits functional properties, including the improving ofhealth growing of muscles [28, 39]. All the nutritionbars under study may easily supply recommended dailyallowance for protein. The mixed nutrition bar containedsignificantly higher amount of protein compared to theothers.The fat content of the mixed bar sample wassignificantly higher than of the sample with banana flourand the bar with the pumpkin seed flour. The ash contentwas higher in the pumpkin seed flour bar, which did notsignificantly differ from the mixed flour sample.The total carbohydrate content solely depends onthe other nutrient components of the nutrition bars. Themixed flour nutrition bar had the lowest carbohydrate(66.11%) content compared to the pumpkin seed flour(73.19%) and banana flour (80.20%) nutrition bar. Thebanana flour and mixed flour nutrition bars had thelowest and highest energy values, respectively (398.60and 424.94 kcal/100 g).Table 2 Nutrient content of pumpkin seed flour and bananaflour (per 100 g)Ingredients Pumpkin seed flour Banana flourMoisture, % 1.20b ± 0.05 3.00a ± 0.75Carbohydrate, % 14.47b ± 1.00 78.30a ± 1.50Protein, % 29.54a ± 1.50 3.9b ± 0.50Fat, % 47.6a ± 2.35 1.8b ± 0.45Crude fiber, % 2.13b ± 0.25 9.9a ± 1.15Calcium, mg 30.07a ± 2.00 22.96b ± 2.50Magnesium, mg 1103.19a ± 10.50 108.05a ± 5.25Phosphorus, mg 3205.13 a ± 11.20 74.54 a ± 3.50Iron, mg 0.31 a ± 0.01 1.22 a ± 0.04Potassium, mg 809.03 a ± 3.25 1491.88 a ± 8.50Energy, kcal 604.44 385.00Values are expressed as mean ± SD. Means in the same row withdifferent superscripts were significantly different (P ≤ 0.05)a b cFigure 2 Appearance of nutrition bars with banana flour (a),pumpkin seed flour (b), and the mix of banana and pumpkinflour (c)Table 3 Nutritional composition of nutrition bars with banana flour, pumpkin seed flor, and mixed flourComposition Banana flour Pumpkin seed flour Mixed flourMoisture content, % 6.94a ± 1.0 6.61a±1.25 6.82a ± 1.55Ash content, % 1.16b ± 0.05 1.46a ± 0.35 1.32a ± 0.50Protein content, % 5.50c ± 0.75 9.74b ± 1.15 14.25a ± 1.55Fat content, % 6.20c ± 0.50 9.05b ± 0.45 11.50a ± 0.75Carbohydrate content, % 80.20a ± 2.50 73.19b ± 3.05 66.11b ± 3.00Energy content, kcal 398.60b ± 3.00 412.72a ± 2.75 424.94a ± 1.80Calcium (Ca), mg 3.75b ± 0.05 3.10c ± 0.25 4.90a ± 0.75Iron (Fe), mg 0.04b ± 0.02 0.2a ± 0.05 0.05b ± 0.03Magnesium (Mg), mg 15.20c ± 0.05 153.45a ± 5.00 118.25b ± 4.25Phosphorus (P), mg 10.20c ± 1.10 450.75a ± 2.55 345.20b ± 2.35Potassium (K), mg 115.20c ± 5.20 220.45a ± 5.55 150.79b ± 4.75Values are expressed as mean ± SD. Means in the same row with different superscripts were significantly different (P ≤ 0.05)286Habiba U. et al. Foods and Raw Materials, 2021, vol. 9, no. 2, pp. 282–289Iron is an essential element whose deficiency causesanemia [40]. According to Institute of Medicine, Foodand Nutrition Board, iron and calcium contents in 100 gof the nutrition bars would contribute less than 4 and10%, respectively, of recommended daily allowancefor men aged 19–50 years reported in 2001 [41]. Ourresults also indicated that 100 g of the nutrition barswith pumpkin seed flour, banana flour, and mixed flourswould provide more than 45, 32, and 10% of phosphorus,respectively [42].The total phenolic content was found to be highest inthe mix flour bar (8.55 ± 0.05 mg GAE/g), compared tothat in the banana flour and pumpkin seed flour samples(7.10 ± 0.03 and 6.45 ± 0.07 mg GAE/g, respectively(Table 4). Phenolics combat with free radicals, which areharmful to human, and stop their further activity [43].DPPH inhibition level indicates free radical scavengingproperty and is a measure of antioxidant potential. TheDPPH radical scavenging activity of the nutrition barsdepended on an amount of phenolics in the bananaflour, pumpkin seed flour, chickpea, and raisins.Food materials rich in phenolics exhibit a high DPPHinhibition level as reported by Abu El-Baky, who studiedphenolic compounds in spirulina and their protectiveproperties [44]. In our research, the mixed flour nutritionbar demonstrated the highest DPPH inhibition level(45.35 ± 0.10%) and, consequently, better antioxidantactivity. The lowest one was found to be 38.25 ± 0.45%(pumpkin seed flour).The textural properties of the bar samples weremeasured using a texture analyzer and includedhardness and fracturability (Table 4). The mix samplehad the highest hardness, while the pumpkin seed flourbar showed the lowest hardness. Fracturability of bananaflour bar was the lowest but it did not significantlydiffer from that of the banana sample, so their texturalproperties were close. Among the other samples, thepumpkin seed flour bar had the least hardness.The color of food products is a critical parameter,especially for bars, which are potentially targetedon children and women. Figure 3 shows the colorparameters for the nutrition bars. There was a significantdifference (P < 0.05) in L* values among all the samples.This could be due to the presence of polyphenols inbanana flour, pumpkin seed flour, and chick pea. Thepumpkin seed flour bar showed a lower L* value than theother bars.All the nutrition bars demonstrated positive a*(redness) and b* values (yellowness). The pumpkin seedflour sample had significantly (P < 0.5) higher a* valuethan the other nutrition bars, which can be explainedby the presence of higher polyphenol concentrations inthe raw materials such as pumpkin seed flour and chickpea. The positive b* value of all the nutrition bars couldbe due to the presence of cornflakes, chickpea, andpumpkin seed flour.Table 4 Total phenolic content, antioxidant activity, and textural properties of nutrition bar with different types of flourNutrition bar Total phenoliccontent, mg GAEDPPHinhibition, %Texture analysisHardness, gf Fracturability, sBanana flour 7.10b ± 0.03 40.50b ± 0.35 41254.00b ± 210.80 17.85b ± 2.10Pumpkin seed flour 6.45c ± 0.07 38.25c ± 0.45 39806.00c ± 205.07 17.50b ± 1.35Mixed flour 8.55a ± 0.05 45.35a ± 0.10 47453.00a ± 195.70 18.95a ± 2.45Values are expressed as mean ± SD. Means in the same column with different superscripts were significantly different (P ≤ 0.05)Figure 3 Color parameter of nutrition bar with bananaflour (a), pumpkin seed flour (b), and the mix of the flour (c)a b cTable 5 Sensory evaluation of nutrition barsNutrition bars Sensory attributesColor Flavor Texture Taste Overall acceptabilityBanana flour 6.60a ± 0.50 5.80a ± 0.65 5.80a ± 0.85 5.20a ± 0.50 5.20a ± 0.85Pumpkin seed flour 6.90b ± 0.43 7.20b ± 0.50 6.80b ± 0.65 6.20a ± 0.80 6.60b ± 0.95Mixed flour 7.80c ± 0.72 8.20c ± 0.95 7.20b ± 0.45 7.60b ± 0.75 7.80c ± 0.55LSD value 0.96 0.94 0.94 1.16 0.96Values are expressed as mean ± SD. Means in the same column with different superscripts were significantly different (P ≤ 0.05)L* a* b*287Habiba U. et al. Foods and Raw Materials, 2021, vol. 9, no. 2, pp. 282–289Sensory assay of the newly nutrition bars includedcolor, flavor, texture, taste, and overall acceptability(Table 5). The analysis showed that there was asignificant (P < 0.5) difference in the sensory attributesamong banana flour, pumpkin seed flour, and mixedflour bars. However, the sample with mixed flourdemonstrated better sensory properties compared to theother nutrition bars.We assessed changes in lipid peroxidation in thenutrition bar with the mix of banana flour and pumpkinseed flour during two months of storage at roomtemperature (25oC). Peroxide value, free fatty acids,and thiobarbuturic acid values of the bar sample aredemonstrated in Table 6.On day 60, the moisture content in the sampleslightly increased, regardless of the packagingmaterial used. Between the packaging materials (lowdensitypolyethylene and high-density polyethylene),a significant difference (P < 0.5) was observed in themoisture content. Chemical changes in the mixed barwere found low in the samples packed in the highdensitypolyethylene compared to those packed in thelow-density polyethylene. After two months of storage,peroxide value, free fatty acids, and thiobarbuturic acidin the mixed nutrition bar became 7.5, 2.1., and 1.5 timeshigher, respectively.CONCLUSIONWe evaluated the quality of nutrition bars containingbanana flour, pumpkin seed flour, and mixed flour. Thesamples with both banana flour and pumpkin seed flour(mixed flour) showed good nutritional quality, withhigher amount of protein (14.25 ± 1.55%), fat (11.50 ±0.75%), and calcium (4.90 ± 0.75 mg/100 g) contentcompared to the other bars. However, the sample basedon pumpkin seed flour demonstrated higher amountof ash (1.46 ± 0.35 mg/100 g), magnesium (153.45 ±5.00 mg/100 g), potassium (450.75 ± 2.55 mg/100 g), andphosphorus (220.45 ± 5.55 mg/100 g) content.Antioxidant activity (45.35 ± 0.10% DPPHinhibition), total phenolic content (8.55 ± 0.05 mg GAE/bar), and textural properties (47453 ± 195.70 gf hardnessand 18.95 ± 2.45 s fracturability) were significantly thehighest in the mixed flour nutrition bar. Sensory analysisfound that the mixed flour nutrition bar was attributed asthe best formulation.Thus, banana flour and pumpkin seed flour showedconsiderable potential as ingredients in the formulationof nutrition bars and improved their nutrient value.Further studies are needed to determine the shelf lifeand in vivo metabolism of nutrition bars enriched withbanana flour and/or pumpkin seed flour.CONTRIBUTIONU. Habiba: conceptualization, methodology,investigation, visualization, and drafting manuscript.M.A. Robin: conceptualization, investigation,visualization, and drafting manuscript. M.M. Hasan:conceptualization, investigation, and draftingmanuscript. M.A. Toma: data analysis, methodology,drafting manuscript, and writing. D. Akhter:data analysis and writing. M.A.R. Mazumder:conceptualization, methodology, project administration,writing, and supervision.CONFLICT OF INTERESTThe authors declare no conflict of interest.ACKNOWLEDGMENTSThe authors gratefully acknowledge Departmentof Food Technology and Rural Industries, BangladeshAgricultural University, Bangladesh for project workresearch grants.