Agriculture and Food Sciences Research ISSN(E) : 2411-6653 ISSN(P) : 2518-0193 Vol. 3, No. 1, 37-44, 2016 http://www.asianonlinejournals.com/index.php/AESR 37 Evaluation of Porridge Made from Composite Flour of Orange-Fleshed Sweet Potato and Enset (Bulla) Flours Abebe Haile1  Martha Geribo2 Esayas Kinfe3 1,2,3Hawassa University, Awassa College of Agriculture, School of Nutrition, Food Science and Technology, Awassa, Ethiopia ( Corresponding Author) Abstract Bulla is the water insoluble starchy product which is separated from Kocho during the decortications process of Enset. However, this extract lacks pro-vitamin A. This study enriched the Bulla with Orange- fleshed Sweet Potato (OFSP) a plant with high levels of β-carotene that can be useful for combating vitamin A deficiency. The porridge was made of composite flours of bulla blended with 30, 35, 40 and 45% OFSP flours were investigated for proximate composition, β-carotene, functional property and sensory acceptability of products using standard methods. The data were analyzed using SAS 1.9 Software. The composite flours percentage moisture, crude (fiber, protein, fat), ash, carbohydrate, gross energy, β-carotene, pH, bulk density and water absorption capacity were found to be in the range of 29.54 to 40.25, (1.66 to 2.05, 2.11 to 2.55, 0.55 to 0.71), 1.76 to 2.11, 53.86 to 63.31, 227.49 to 268.11 Kcal/100 g, 386.68 to 558.05 μg/100 g, 4.46 to 5.71, 0.58 to 0.80 and 1.70 to 4.87 ml/g, respectively. While, the composite flours porridge percentage moisture, crude fiber, ash, crude protein, crude fat, carbohydrate, gross energy, β-carotene, pH and viscosity content found to be in the range from 43.42 to 58.03, 1.32 to 1.79, 2.39 to 2.78, 2.01 to 2.31, 0.71 to 0.82, 35.21 to 48.63, 155 to 211.11 Kcal/100 g, 201.46 to 301.50 μg/100 g, 5.71 to 5.82 and 515 to 728 cps, respectively. The porridge OB4PM2 (45% OFSP and 55% Bulla) was most preferred due to its color, odor, flavor and overall acceptability with panelist scored value of 4.28, 4.33, 4.39 and 4.45, respectively. Moreover, OB4PM2 porridge was found to be good source of ash, energy and β-carotene content. Keywords: Bulla, Composite flour, Orange-fleshed sweet potato, Porridge, β-carotene, Viscosity. Contents 1. Introduction ............................................................................................................................................................................... 38 2. Materials and Methods ............................................................................................................................................................. 38 3. Results and Discussions ............................................................................................................................................................ 40 4. Conclusion .................................................................................................................................................................................. 43 References ...................................................................................................................................................................................... 43 Citation | Abebe Haile; Martha Geribo; Esayas Kinfe (2016). Evaluation of Porridge Made from Composite Flour of Orange-fleshed Sweet Potato and Enset (Bulla) Flours. Agriculture and Food Sciences Research, 3(1): 37-44. DOI: 10.20448/journal.512/2016.3.1/512.1.37.44 ISSN(E) : 2411-6653 ISSN(P) : 2411-6653 Licensed: Contribution/Acknowledgement: This work is licensed under a Creative Commons Attribution 3.0 License All authors contributed to the conception and design of the study. Funding: This study received no specific financial support. Competing Interests: The authors declare that they have no conflict of interests. Transparency: The authors confirm that the manuscript is an honest, accurate, and transparent account of the study was reported; that no vital features of the study have been omitted; and that any discrepancies from the study as planned have been explained. History: Received: 14 April 2016/ Revised: 6 May 2016/ Accepted: 18 May 2016/ Published: 13 June 2016 Ethical: This study follows all ethical practices during writing. Publisher: Asian Online Journal Publishing Group http://crossmark.crossref.org/dialog/?doi=10.20448/journal.512/2016.3.1/512.1.37.44 http://creativecommons.org/licenses/by/3.0/ https://orcid.org/orcid-search/quick-search?searchQuery=Abebe%20Haile https://orcid.org/orcid-search/quick-search?searchQuery=Martha%20Geribo https://orcid.org/orcid-search/quick-search?searchQuery=Esayas%20Kinfe http://search.crossref.org/?q=10.20448/journal.512/2016.3.1/512.1.37.44 Agriculture and Food Sciences Research, 2016, 3(1): 37-44 38 1. Introduction Bulla is a processed starch made from Enset (Enset ventricosum). It is obtained when the scrapings and pulps were squeezed, separating of the liquid. Collecting the pulpy white juice and left for one or two days to settle the resultant starch to concentrate into white flour. The starch that separates out from the liquid concentrates into a white powder. This product can be either fermented in pit or directly cooked without fermentation [1, 2]. Bulla is a good source of calories. It can be prepared as pancake, porridge and made into soup. Bulla fulfills both the nutritional requirement and income of the family there by providing household financial security that is by frequent sale of some amounts of fermented Bulla from the storage pit. The price of bulla is higher than Kocho even at local market [1]. Bulla can be stored for a long period of time without spoiling. The shelf life of Bulla depends on the age of the harvested Enset plant and the way of packing system. Proper packaging is needed to protect the spoilage. If there are pockets of air, or exposed to air, molds and other spoilage organisms can grow and soften the product. Due to its moisture content there will be taste and color change happen to the product [3]. Bulla was considered the best quality Enset food. However, it is low in protein, fat content and has no adequate pro-vitamin A for the daily requirement of a normal person. According to the study of Minaleshewa [2] and Tilahun, et al. [4] protein and fat content of Bulla were renged from 0.4-0.8 and 0.2-0.4g, respectively. The Vitamin “A” content of Enset products record was 0-0.2% [4]. As a result, it is a problem for those people who use Enset product (Bulla) as staple or co-staple food have a chance of being affected by vitamin A deficiency. Orange-fleshed Sweet Potato (Ipomoea batatas ) is an important tuber crop grown in the tropics, sub-tropics and warm temperate regions of the world for its edible roots crop. The roots contain significant amount of carbohydrate constitute mainly in the forms of starch, sugar and dietary fibers, which play an important role of providing low-cost energy in the diet of consumers. Beside carbohydrate, it contains high levels of ß-carotene and appreciable amount of minerals. Orange-fleshed Sweet Potato (OFSP) varieties are being promoted as food based intervention to combat vitamin A malnutrition [5]. The flesh color of the root varies from various shades of white, cream, yellow to dark- orange depending upon the carotenoids content [6]. Carotenoids have been linked with the enhancement of immune system and decreased risk of degenerative diseases such as cardiovascular problems. Dietary fiber has the potential to reduce the incidence of a variety of diseases in man including colon cancer, diabetes, heart diseases and digestive disturbances [7]. The primary role of enriching the Enset product (Bulla) with Orange-fleshed Sweet Potato was to upgrade the Vitamin A content of the products. It is the intervention falls in the latter category of food based approaches which is particularly suited for rural areas where the Enset products used as a staple food. A food based strategy has the advantage of bringing more nutrients, vitamin “A” and more sustainable approach. Enriching the indigenous root crop Enset product (Bulla) by mixing with orange-fleshed sweet potato can be a good solution to improve the nutritional quality of household diets. Vitamin A is a fat-soluble vitamin that was needed in small quantities for several metabolic activities in the body. When vitamin A intake is below required levels, a number of manifestations collectively known as vitamin A deficiency (VAD) disorders occur. This vitamin deficiency has manifested as blindness, increased susceptibility to infection and closely associated with increased mortality and morbidity [8]. The causes of VAD occurs when vitamin A intake or liver stores fail to meet daily metabolic requirements and the most common cause is a persistently low intake of vitamin A-rich foods. Therefore, the objective of this study is enriching of Enset product (Bulla) flour with Orange-fleshed Sweet Potato to prepare porridge of having high vitamin A content from the blended flours. Moreover, to determine the physicochemical, β-carotene content and sensory acceptability of the products. 2. Materials and Methods 2.1. Sample Collection Raw Bulla sample was purchased from Hawassa local market. Raw Orange-fleshed Sweet Potato of Tulla variety (CIP-420027) was collected from Southern Agricultural Research Center of Primary Quality Sweet Potato Vine Multiplication Center (Wondo Genet Farm). All the samples were properly packed and transported to the laboratory of Food Science and Technology, Hawassa University. The OFSP was stored at -18 0C (Haier chest freezer Model HCF 588) to protect spoilage. While Bulla was stored at dry and ambient temperature until further processing. 2.2. Bulla Flour Preparation Bulla sample was prepared according to procedure outlined by Minaleshewa [2]. The semi dried bulk Bulla sample was spreaded on clean dry wood board and the long fibers were removed manually. The sample was then sieved through 500µm sieve (FRITSCH, test sieve, Made in German) to remove the hard particles and made it uniform size and the contents were mixed. Bulla flour was packed by polyethylene bag and stored at room temperature. 2.3. Orange-fleshed Sweet Potato Flour Preparation Orange-fleshed sweet potato flour was prepared according to the procedure outlined by Owori, et al. [9]. The OFSP was taken out from deep freezer and kept on the laboratory table for four hours until its temperature was raised to room temperature. The OFSP was washed with potable water to remove any foreign bodies and then the outer skin was peeled by peeling machine (Robot coupé H. Biaugeaup Model CL 30). The remaining unnecessary parts were removed manually and rinsed by clean potable water. The OFSP was chopped to minimize the size for the slicer machine. The chopped sweet potato was then sliced to a uniform size of 3 mm by the slicer machine (H. Biaugeaup Model W1 9901). The slices were soaked in 1% w/v sodium chloride solution for 30 minutes. The function of salt is to inhibit the growth of microorganisms on the slices while drying. The slices were dried on the flat racks of solar dryer. The dried sample was milled by electronic grinder and sieved by 500µm sieve (FRITSCH, test sieve, Made in German). The flour obtained was double packed by dark polyethylene bags stored in dry and dark place to protect oxidation of ß- carotene. Agriculture and Food Sciences Research, 2016, 3(1): 37-44 39 2.4. Preparation of OFSP Added Bulla Composite Flour The formulation of OFSP with Bulla for porridge making were done based on the recommended dietary intake (RDI) of adult person to maintain a healthy life. It also allows creating unique and delicious recipes based on the acceptability of the users, see Table 1 below. Table-1. Proportion of OFSP powder used to formulate the composite flour Bulla composition /Kg OB4PM1 OB3PM1 OB2PM1 OB1PM1 B1PM1 OFSP 45% 40% 35% 30% - Bulla 55% 60% 65% 70% 100% Total 1Kg 1Kg 1Kg 1Kg 1Kg Note: * PM1→ is the code of treatments before cooking Table-2. Proportion of ingredients used to prepare porridge Bulla composite flour porridge /kg OB4PM2 OB3PM2 OB2PM2 OB1PM2 B1PM2 OFSP 45% 40% 35% 30% - Bulla 55% 60% 65% 70 100% Water (mL/kg) 1500 1500 1500 1500 1500 Oil (mL/kg) 20 20 20 20 20 Note: *PM1→ treatments before cooking, *PM2 → treatments after cooking. B1PM1=100% of Bulla flour, OB1PM1=30% OFSP + 70% of Bulla, OB2PM1=35% OFSP + 65% of Bulla, OB3PM1=40% OFSP + 60% of Bulla and OB4PM1=45% OFSP + 55% of Bulla composite flour; B1PM2=100% Bulla porridge, OB1PM2=30 % OFSP + 70% Bulla, OB2PM2=35% OFSP + 65% of Bulla, OB3PM2=40% OFSP + 60% Bulla and OB4PM2=45% OFSP + 55% Bulla composite flour porridge. 2.5. Porridge Preparation Bulla based porridge was prepared using the methods outlined by Yewelsew, et al. [10]. One kilogram of composite flours was mixed with 1500 mL/kg of water, kneaded well in the pot, and boiled until all particles became soluble while boiling 20mL oil was added. Then the composite flour porridge was cooked at the temperature of 100 0C for 10 minutes. 2.6. Chemical Analysis 2.6.1. Determination of ß-carotene Contents ß-carotene content in the food was determined as the procedure outlined by Rodriguez, et al. [11] based on Spectro-photometric test. 2.6.2. Determination of Proximate Composition The Proximate composition of flour and composite flour porridge were determined by using the standard method of Association of Official Analytical Chemists (AOAC) [12]. The total carbohydrate amount in the sample was determined by difference: Total c𝐚𝐫𝐛𝐨𝐡𝐲𝐝𝐫𝐚𝐭𝐞 % = 𝟏𝟎𝟎 − (𝐏 + 𝐅 + 𝐀 + 𝐌) Whereas: P = the mass percentage of crude protein, F = the mass percentage of crude fat A = the mass percentage of ash, M = the mass percentage of moisture 2.6.3. Determination of Gross Energy The energy value was determined by calculation using the relationship from fat, carbohydrate and protein contents of the Atwater’s Conversion Factors; (4kcal/g) for protein, (9kcal/g) for fat and (4 kcal/g) for carbohydrates and expressed in calories. Gross energy (kcal/g) = (4 × protein) + (4 × carbohydrate) + (9 × fat) 2.7. Determination of Physical and Functional Properties 2.7.1. pH Value The pH of the samples was determined from 1/10 dilution of sample by glass electrode attached to digital pH meter as their combination ratio before cooking and after cooking of each composite flours samples were done according to the method described by Yirmaga [13]. The pH meter (MP 511 Lab. pH meter, China) was calibrated using pH 4.0 and 7.0 buffers prior to determination of the pH of the samples. 2.7.2. Bulk Density The bulk density of OFSP added Bulla composite flours were determined by using method [14]. Agriculture and Food Sciences Research, 2016, 3(1): 37-44 40 2.7.3. Water Absorption Capacity Water absorption capacity OFSP added Bulla composite flours were determined using the method [15]. 2.8. Viscosity The viscosities of the composite flours porridge were measured using the method of [16]. 2.9. Sensory Evaluation Sixty-two panelists who were the students of the School of Nutrition, Food Science and Technology, Hawassa University did the consumer acceptability of composite flour porridge. The panelists ranked the color, odor, flavor, and overall acceptability of composite flours porridge using a five point hedonic scale (5 Extreme like, 4 Like very much, 3 Like, 2 Dislike and 1 Dislike very much). The composite flours porridge samples were presented in triplicate. Samples were being ordered on the table without providing any information to the panelists. A bottle of tape water with white plastic cups was given to rinse their mouth after each test. They use their observation and sense organ on making decisions, and they interpret the nature of a sample. The results were recorded and analyzed to determine the significance of variations of sensory attributes of the products average scores. 2.10. Ethical Approval The study protocol was approved by the ethical committee of Hawassa University College of Medicine and Health Science for sensory evaluations. 2.11. Statistical Analysis The data were analyzing using the SAS 9.1 Software. Analysis of variance (ANOVA) was used for the analysis. Fisher`s Least Significance Difference (LSD) test was used to determine the significance of mean differences of the results. The level of statistical significance was set at (p<0.05). 3. Results and Discussions 3.1. Proximate Composition, Physicochemical and Functional Properties Table-3. Proximate composition (%) of OFSP added Bulla composite flours and porridge. Treatment Moisture content Crud fiber Ash Crude protein Composite flours B1PM1 48.25±0.01d 0.39±0.01i 1.26± 0.01i 1.06±0.01h OB1PM1 40.38± 0.00g 1.66±0.01e 2.11±0.01g 1.76± 0.01g OB2PM1 33.72± 0.01h 1.81±0.00c 2.24± 0.01f 1.88±0.01e OB3PM1 31.62±0.01i 1.92±0.01b 2.38±0.01e 2.01±0.01d OB4PM1 29.54±0.01j 2.05±0.01a 2.55±0.00c 2.11±0.01c Porridge B1PM2 60.30±0.01a 0.12± 0.01j 2.00±0.01h 1.90±0.00f OB1PM2 58.03±0.01b 1.32± 0.01h 2.39±0.01e 2.01±0.00d OB2PM2 50.11±0.01c 1.49± 0.01g 2.51±0.01d 2.12±0.01c OB3PM2 46.75±0.01e 1.62± 0.01f 2.62±0.01b 2.21±0.01b OB4PM2 43.42±0.00f 1.79± 0.01d 2.78±0.01a 2.31±0.01a Note: *PM1→ treatments before cooking, *PM2 → treatments after cooking. B1PM1 = 100% of Bulla flour, OB1PM1 = 30% OFSP + 70% of Bulla, OB2PM1 = 35% OFSP + 65% of Bulla, OB3PM1=40% OFSP + 60% of Bulla and OB4PM1=45% OFSP + 55% of Bulla composite flour; B1PM2 = 100% Bulla porridge, OB1PM2 = 30 % OFSP + 70% Bulla, OB2PM2 = 35% OFSP + 65% of Bulla, OB3PM2 = 40% OFSP + 60% Bulla and OB4PM2 = 45% OFSP + 55% Bulla composite flour porridge. Means ± SD, values within the same column with different superscript letters are significantly different from each other (p<0.05). Table 3 shows that the moisture content of OFSP and Bulla composite flours and porridges were ranged from 31.62-48.25% and 43.42-60.30 %, respectively. The highest moisture content observed in B1PM2 (60.30%) followed by OB1PM2 (58.03%) and the least was for the OB4PM1 (29.54%). Moisture content of OFSP and Bulla composite flour and porridge were significantly different (p<0.05) to each other. According to Kalekristos [3] the moisture content of Bulla bought from Addis Ababa supper market was found in the range of 44 to 57%, that was contain more moisture than the present study. There were significant differences in moisture content between the treatments, before and after cooking of the porridge. The highest moisture content of composite flours and porridges scores were (OB1PM1) 40.38% and OB1PM2 (58.03%), respectively. The difference might be due to addition of more water while cooking the porridge. As the amount of OFSP flour increases in the composite flours, the moisture content of flour and porridge were decreased gradually. Crud fiber contents of Bulla 0.39%, OFSP added Bulla composite flour ranged from 1.66 to 2.05%, while Bulla porridge ranged from 0.12 to 1.79%. There were significant difference (p<0.05) among the treatments. Higher crude fiber (2.05%) content was obtained in Bulla based composite flour OB4PM1, while the lowest (0.12%) was obtained for porridge B1PM2. According to the previous reported literature, Bulla was the decanted fluid of the decortications processing of Enset plant and it is very poor in fiber content of recorded values were in the range from 0.6 to 0.8% [3]. As the amount of OFSP flour increases in the composite flours, the fiber content increased gradually. This might be due to the crude fiber content of OFSP more than Bulla flour. However, the fiber content of OFSP added Bulla composite flours were not fulfilling the RDA of fiber for healthy adult. According to FAO Food Standards Program Agriculture and Food Sciences Research, 2016, 3(1): 37-44 41 [17] of the RDA of fiber for healthy person set at 25 to 38 g/day which was significantly different from the present study. Hence, Bulla composite flours porridge needs additional fiber source of food. Ash actually a much more general term that can refer to a number of substances in the food. The ash is residue that remains after heating and removing water or it refers to any inorganic material present in food [18]. The ash content of OFSP added Bulla composite flour and porridge were ranged from 1.26-2.55% and 2.39 - 2.78%, respectively. According to Minaleshewa [2] and Yirmaga [13] the ash content of Bulla was found 0.2 and 2.39 %, respectively. The highest ash content was observed for OB4PM2 (2.78%) whereas the least for B1PM1 (1.26%). The ash content of composite flours and porridges were significantly different (p<0.05) to each other. It might be due to the leaching of some minerals from cooking utensils. As the amount of OFSP flour increased in the composite flours, the crude ash content increased. The increment of ash content show that the increasing the density of inorganic material such as minerals present in food. The protein value for different Bulla based composite flour and porridge were presented in Table3 shows that the highest protein record was for OB4PM2 (2.31%) and the least was observed for B1PM1 (1.06%). There were significant different (p<0.05) observed among protein content except for OB4PM1 and OB3PM1. The crude protein content of Bulla was recorded 1.6g/100 g while the protein content of OFSP added Bulla composite flour was in the range of 1.76 to 2.11%. These, value were greater than the crude protein content of Bulla reported values of 0.6 and 0.4-0.8 g/100g by Tilahun, et al. [4] and Minaleshewa [2] respectively. The highest protein content of Bulla composite porridge score was (2.31%) observed in OB4PM2. When the percentage of OFSP increases, the protein content of composite flour increased gradually. This might be due to relatively higher protein content of OFSP compared to Bulla. However, protein contents of the composite flours were not enough for daily requirement of healthy person which was in the range of 0.80 to 1.52 g/kg/d [17, 18]. Table-4. Proximate composition (%) of crude fat, carbohydrate, energy and β-carotene of composite flours and porridges Note: *PM1→ treatments before cooking, *PM2 → treatments after cooking (porridge). B1PM1=100% of Bulla flour, OB1PM1=30% OFSP + 70% of Bulla, OB2PM1=35% OFSP + 65% of Bulla, OB3PM1=40% OFSP + 60% of Bulla and OB4PM1=45% OFSP + 55% of Bulla composite flour; B1PM2=100% Bulla porridge, OB1PM2=30 % OFSP + 70% Bulla, OB2PM2=35% OFSP + 65% of Bulla, OB3PM2=40% OFSP + 60% Bulla and OB4PM2=45% OFSP + 55% Bulla composite flour porridge. Means ± SD, values within the same column with different superscript letters are significantly different from each other (p<0.05). As it is indicated in Table 4 the fat content of OFSP added Bulla composite flour and porridge were ranged from 0.26 - 0.70 % and 0.22- 0.82%, respectively. The present studied samples were slightly different from Minaleshewa [2] fat content observed value ranged from 0.2 to 0.4 g/100 g. The fat content of the OFSP added Bulla composite flours and porridges were significantly different (p<0.05) to each other. The highest and lowest fat content values were observed for OB4PM2 (0.82%) and B1PM2 (0.22%), respectively. However, fat content of Bulla composites were not enough to satisfying the daily requirements of adult person. The results indicating that both Bulla and OFSP are poor sources of crude fat. Table 4 show that the carbohydrate content of OFSP added Bulla composite flour ranged from 48.78 to 63.31%, while that of porridge ranged from 35.00 to 48.63%. The highest and lowest carbohydrate content values were observed for composite flour OB4PM1 (63.31%) and porridge B1PM2 (35%), respectively. According to Minaleshewa [2] the carbohydrate content of Bulla recorded to be 43.6 to 55.4g/100g, which was less than from the present study finding. There were significant difference (p<0.05) observed between carbohydrate content of the composite flours and porridges. Due to the dilution of more water for porridge processing, the sample contained high amount of water. On the other hand as the percentage of OFSP is increased the carbohydrate content of both the composite flours and porridges were significantly increased. The carbohydrate content of the Bulla composite flour products were somehow enough for satisfying daily requirements of adult person. The findings indicating both Bulla and OFSP were good sources of carbohydrate. The RDA of carbohydrate for healthy person was found to be 130 g/day [18]. The gross energy content of OFSP added Bulla composite flours and porridges were ranged from 201.07 - 268.11 and 149.58-211.11Kcal/100gm, respectively. The highest gross energy content was found for OB4PM1 (268.11 Kcal/ 100gm), while the least was for B1PM2 (149.58Kcal/ 100gm). The gross energy content were significantly different from each other (p<0.05). According to the study of Almaz [19] and Minaleshewa [2] the energy content of Bulla was scored 1860 and 1410 -1950 kJ/kg, respectively which were different from present study. The highest energy content of composite flour and porridge were scored for OB4PM1 (268.11 Kcal/100g) and OB4PM2 (211.11 Kcal/100g), respectively. There were significant difference (p<0.05) between the energy content of composite flour and porridge. When the percentage of OFSP increases in the composite flour, the energy content of composite flour and porridge were Treatment Crude fat Total carbohydrate Gross energy, Kcal/100gm β-carotene, μg/100gm Composite flours B1PM1 0.26±0.00h 48. 78±0.02e 201.07±0.00f Nil OB1PM1 0.55±0.01g 53.86±0.01d 227.49±0.07d 386.68±0.04d OB2PM1 0.59±0.01f 60.09±0.01c 253.19±0.04c 451.13±0.02c OB3PM1 0.64±0.00e 61.73±0.02b 260.33±0.61b 515.58±0.03b OB4PM1 0.71±0.01d 63.31±0.00a 268.11±0.05 a 558.05±0.00a Porridges B1PM2 0.22±0.01i 35.00±0.00h 149.58±0.05 j Nil OB1PM2 0.71±0.01d 35.21±0.00h 155.27±0.00i 201.46±0.34h OB2PM2 0.74±0.01c 42.71±0.02g 185.98±0.05 h 231.54±0.03g OB3PM2 0.78±0.00b 45.71±0.02f 198.72±0.06g 265.71±0.01f OB4PM2 0.82±0.01a 48.63±0.01e 211.11±0.07e 301.50±0.02e Agriculture and Food Sciences Research, 2016, 3(1): 37-44 42 enhanced gradually. This might be due to the relatively higher energy content of OFSP compared to Bulla. The results indicate that the composites are good source of energy. As mentioned on the previously reported literatures, Bulla was poor in β-carotene content. Therefore, it can be enhanced by the application of β-carotene rich food items to improve the β-carotene of the diet. The effect of addition of OFSP on β-carotene content of Enset (Bulla) based composite flour and porridge is shown in Table 4. The β-carotene content of solar drayed OFSP powder was scored 1280 μg/100g, while the β-carotene content of OFSP added Bulla composite flour values were ranged from 386.68 to 558.05 μg/100g. Similarly, the β-carotene content of the OFSP added Bulla composite porridge values were ranged from 201.46 to 301.50 μg/100g. The highest β-carotene content observed for the composite flour OB4PM1 (558.05μg/100gm) followed by OB3PM1 (515.58μg/100gm) and the least was observed for porridge OB1PM2 (201.46μg/100gm). The β-carotene content of composite flours and porridge were found to be significantly different (p<0.05) to each other. According to the study of Stella [6] and Aurélie [20] the β-carotene content of raw OFSP was observed in the ranged values from 1,255 to 2,400 and 1,596 to 2,382 μg /100g of edible portion, respectively which is different from present study. The β- carotene content of raw OFSP flour comparing with the composite four was significantly different (p<0.05). This might be due to the degradation of β-carotene in the drying process and mixing with food having none β-carotene. The β-carotene content of composite flour is significantly higher than bulla based porridge (p<0.05). This might be due to the effect of cooking temperature on β-carotene content in the preparation of the porridge. On the other hand when the percentage of OFSP increases, the β-carotene content of composite flour and porridge enhanced gradually. This is due to the higher β-carotene content of OFSP compared to Bulla. The results indicate that the composites were good source of β-carotene even though it is less than the one indicated by Stella [6] and Aurélie [20]. According to Kósambo [21] the average β-carotene loss on the finished products of porridge made from OFSP flour was 65%. In the present study the loss of β-carotene content during cooking process of OFSP and Bulla composite flour porridge was 256.55 μg/100g (45.97%). The finding show that the β-carotene degradation decreased. This might be due to short cooking time, temperature and genetic variation of the crop. A person who eats 45% OFSP and 55% Bulla composite porridge he/she gain 301.50μg that was (33.5%) of the daily requirement of adult. The daily requirement of β-carotene of healthy person range between 250 to 900µg/day [17, 18]. 3.2. Physical and Functional Properties Composite Flours or/and Porridge Table-5. Physical and functional properties, and pH of bulla based composite flours and porridge Treatment pH /100mg Bulk density, g/ml WAC, g/ml3 Viscosity, cps Composite flours B1PM1 4.0±0.01c 0.92±0.01a 0.76±0.00e OB1PM1 4.46±0.01c 0.80±0.01b 1.70±0.10d - OB2PM1 5.27±0.01b 0.69±0.02c 3.07±0.12c - OB3PM1 5.64±1.15b 0.61±0.01d 4.00±0.00 b - OB4PM1 5.71±0.03a 0.58±0.01e 4.87±0.15a - Porridge B1PM2 5.13±0.01c 515±1.00e OB1PM2 5.71±0.00a - - 525.67±0.58d OB2PM2 5.73±0.01a - - 553.00±1.00c OB3PM2 5.77±0.01a - - 624.67±0.58b OB4PM2 5.82±0.02a - - 728.00±1.73a Note: *PM1→ treatments before cooking, *PM2 → treatments after cooking. B1PM1=100% of Bulla flour, OB1PM1=30% OFSP + 70% of Bulla, OB2PM1=35% OFSP + 65% of Bulla, OB3PM1=40% OFSP + 60% of Bulla and OB4PM1=45% OFSP + 55% of Bulla composite flour; B1PM2=100% Bulla porridge, OB1PM2=30 % OFSP + 70% Bulla, OB2PM2=35% OFSP + 65% of Bulla, OB3PM2=40% OFSP + 60% Bulla and OB4PM2=45% OFSP + 55% Bulla composite flour porridge. Means ± SD, values within the same column with different superscript letters are significantly different from each other (p<0.05). WAC-water absorption capacity, cps-centi pose second. The pH value of Bulla was 4.00/100mg; OFSP added Bulla composite flour and porridge were found in the range from 4.46-5.82/100mg as presented in Table 5. The highest pH value observed for bulla based porridge OB4PM2 (5.82/100mg), while the least value was seen for composite flour B1PM1 (4.00/100mg). This might be due to cooking temperature increases the pH value of the samples by denaturing the amino acids in the food. As the percentage of OFSP increases, the pH value of composite flour and porridge were enhanced. The composite flour pH values were significantly different (p<0.05) to each other. While the pH values for porridges were not significantly different (p>0.05) to each other. According to the study of Kalekristos [3] Bulla bought from Addis Ababa supper market pH value was 4.9/100mg which was less acidic compared to present study. As mentioned in previous sections, the bulk density of a powder depends on how closely individual particles packed together and it play important roles during mixing in dough formation [14]. The bulk densities for Bulla was 0.92 g/ml, OFSP added Bulla composite flour were ranged from 0.58-0.91g/ml. The highest bulk densities was observed for B1PM1 (0.92g/ml) while the least was for OB4PM1 (0.58g/ml). The bulk densities of OFSP added Bulla composite flours were significantly different from each other (p<0.05). As the amount of OFSP powder increases in the composite, the bulk density decreased gradually. This is due to particle size of OFSP is less than Bulla. The water absorption capacity of flour indicates how much water to add during food preparation and interrelated to gelatin properties. Hence, the low water absorption capacity recorded by the flours could explain the less gel formation capacity [16]. The finding of the water absorption capacity of Bulla in this study was 0.76 ml/g, while the Agriculture and Food Sciences Research, 2016, 3(1): 37-44 43 water absorption capacity of OFSP added Bulla composite flours were ranged from 1.70 to 4.87 ml/g as shown in Table 5. As the amount of OFSP flour increases in the composite, the water absorption capacity increased gradually. This might be due to the water absorption capacity of OFSP powder was higher compared to Bulla flour. The highest water absorption capacity of OFSP added Bulla composite was for OB4PM1 (4.87 g/ml3) and the least was for B1PM1 (0.76 g/ml3). There were significantly different from each other (p<0.05). The value of viscosity of Bulla porridge was 515.00 c.p.s, OFSP added Bulla composite flours porridge were ranged from 525.67-728.00 c.p.s. (see above Table 5). The highest viscosity value was observed for OB4PM2 (728.00 c.p.s) followed by OB3PM2 (624.67) and the least for B1PM2 (515.67 c.p.s.). There were significantly difference (p<0.05) between each treatment. As the amount of OFSP flour increases in the composite flours, the viscosity of the porridge was also increased. This might be due to the water absorption capacity of the OFSP flour. The higher the viscosity is a desirable quality attribute of flour for cooking purpose. Liquids make up of small molecules have a low viscosity and liquids with long chain molecules have a much higher viscosity [22]. 3.3. Sensory Evaluation of Bulla Based Composite Flours Porridge Table-5. Organoleptic evaluation score of OFSP added Bulla composite flours porridge Note: *PM1→ treatments before cooking, *PM2 → treatments after cooking. B1PM1= 100% of Bulla flour, OB1PM1=30% OFSP + 70% of Bulla, OB2PM1=35% OFSP + 65% of Bulla, OB3PM1=40% OFSP + 60% of Bulla and OB4PM1=45% OFSP + 55% of Bulla composite flour; B1PM2=100% Bulla porridge, OB1PM2=30 % OFSP + 70% Bulla, OB2PM2= 35% OFSP + 65% of Bulla, OB3PM2=40% OFSP + 60% Bulla and OB4PM2=45% OFSP + 55% Bulla composite flour porridge. Means ± SD, values within the same column with different superscript letters are significantly different from each other (p<0.05). The porridges were prepared by blending of OFSP and Bulla in different combination were analyzed for various sensorial attributes for their acceptance by using 5 point hedonic scale. When you are offering a new product or changing ingredients of food items, it is important to know what likely the consumer reaction is to be to the characteristics of your product. At the present study all panelists were instructed to make their own individual assessments, according to the evaluation criteria provided for each samples on the basis of, color, odor, flavor and overall acceptability. The organoleptic evaluation of OFSP and Bulla composite flours porridge score values ranged from 1.05-4.28, 1.00-4.33, 1.3-4.39 and 1.25-4.45 for attributes of color, odor, flavor and overall acceptability, respectively as indicated in above Table 6. There were Significant difference (p<0.05) was observed among the treatments. The highest preferences of Bulla composite porridge by color, odor, flavor and overall acceptability were scored 4.28, 4.33, 4.39 and 4.45, respectively. It was observed that the Bulla based porridge sample OB4PM2 , prepared by addition of 45% OFSP flour was liked most by sensory panelist as compared to the other combinations. 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