Orange-fleshed Sweet Potato Flour Research Articles

Bio-fortification of Cereals Based Bread Using Orange Fleshed Sweet Potato for Alleviating of Vitamin-A Deficiency

Ethiopia is one of the developing countries with a high prevalence of micronutrient deficiencies and protein-energy malnutrition. Vitamin A is one of the most versatile vitamins with roles in various functions such as vision, immune defense, maintenance of body linings and skin. Fortifying cereals through processing and conventional breeding can tackle micronutrient deficiency. Orange Fleshed Sweet Potato (OFSP) is a source of food that contains useful β-carotene, starch, mineral, dietary fiber, and vitamins. The inclusion of OFSP enhances the beta-carotene content of bread. This research aims to develop Vitamin A rich cereals based bread enhanced with orange-fleshed sweet potato. The straight dough baking method was used to develop bread. Beta-carotene content and physical properties of bread were done based on standard methods. Blending of OFSP flour in cereals significantly influenced the physical properties of bread. The total carotenoid content of bread products with 10% of OFSP Flour was 3.998 mg/100 g while that of beta-carotene is 23.217 mg/100 g. Inclusion of OFSP in composite flour increased the total carotenoid and beta-carotene content of bread. Generally, formulated flour has huge advantageous as a means of enhancing beta-carotene content and helps to alleviate vitamin A deficiency.

Nutritional and sensory qualities of extruded Ready-To-Eat baby foods from orange-fleshed sweet potato enriched with amaranth seeds, and soybean flour

Adequate nutrition is critical during infancy and childhood because life phases are marked by significant physical, mental, and changes in behaviour, such as fast growth, weight gain, the development of cognitive and psychomotor abilities, and a change in dietary preferences. This study was carried out to investigate the effect of extrusion cooking and blend proportions on the nutritional qualities of extruded ready-to-eat baby foods. Different blends of orange-fleshed sweet potato, amaranth seeds, and soybean flour were used to formulate foods and analyzed for proximate, minerals, vitamin A content, anti-nutrient content, physical properties, and sensory qualities. Extrusion cooking was conducted at a temperature of 90oC, screw speed of 400 rpm, and feed moisture content of 35%. The results reveal that extruded ready-to-eat baby foods had a high protein content of 15.72%, total minerals (5.39%), carbohydrate content (80.58%), crude fibre content (5.04%), fat content (6.05%), energy value (380.84 kcal/100g), energy-to-protein ratio (128.67 kcal/g of protein) and vitamin A content (1044.70 REA µg/100g). The micronutrients of extruded baby foods resulted in high iron content of 3.10 mg/100g, zinc content (0.64 mg/100g), manganese content (0.90 mg/100g), copper content (0.97 mg/100g), magnesium content (81.70 mg/100g), calcium content (61.22 mg/100g), potassium content (68.18 mg/100g) and sodium content (41.44 mg/100g). The produced ready-to-eat baby foods showed a reduction in anti-nutrients as well as acceptable levels of phytate content which ranged from 0.47-1.79 mg/100g, oxalate content (0.16 – 0.50 mg/100g) and saponin content (0.20 – 0.48 mg/100g). All produced foods were highly accepted through sensory evaluation. These important findings confirm that extrusion cooking is useful in the production of nutrient-dense baby foods. In addition, the most significant observation of this study is that the produced foods could be used for under-five years children who suffer from protein-energy malnutrition and micronutrient deficiencies. These findings will also contribute to food and nutrition security.

Protein Quality of Extruded Ready-to-Eat Baby Foods from Orange-Fleshed Sweet Potato, Amaranth Seeds, and Soybean Flour Blends

Purpose: Protein quality refers to the total protein content, essential amino acid content, and digestibility of a protein. Source, bioavailability, food matrix, and processing conditions all have an impact on protein quality. Protein quality can be lost during food processing. This study was carried out to investigate the effect of extrusion cooking and blend proportions on the protein quality of extruded ready-to-eat baby foods.
 Methodology: Different blends of orange-fleshed sweet potato, amaranth seeds, and soybean flour were used and analyzed for protein quality including in vitro protein digestibility (IVPD) of extruded ready-to-eat baby foods. In addition, nutrient damage due to heat or processing temperature was evaluated by analyzing available lysine in the end products to ensure the quality of extruded ready-to-eat baby foods. Extrusion cooking was carried out at a temperature of 90oC, screw speed of 400 rpm, and feed moisture content of 35%.
 Findings: The results showed that IVPD ranged from 54.05 to 91.87%. The available lysine as a parameter to evaluate the nutritional damage due to thermal processing ranged from (1.69 to 2.79%). This research predicts the potential availability of highly digestible protein as well as the assurance of lysine availability once extrudates are consumed. Achieving high lysine retention during extrusion cooking depends on a number of factors, including low temperature, high screw speed, high feed moisture content, and high shear forces that lead to a short residence time.
 Recommendation: It is important to conduct more research on how extrusion cooking affects the molecular and physical interactions between starches, proteins, lipids, and phenolic compounds.

Nutritional Evaluation of Orange-fleshed Sweet Potatoes (Ipomoea batatas) Flour Extracted from Various Processing Techniques

Orange flesh sweet potato (OFSP) is one of the world’s most important food security-promoted root crops. Unfortunately, the crop is underutilized in Nigeria due to its poor storability technics and rapid deterioration in storage. To establish baseline data for its better storage and utilization for upgrading its value chain, an alternative approach of processing is thereby expedient to curb the menace. Thus, the nutritional evaluation of orange-fleshed sweet potato (Ipomoea batatas) flour extracted from various processing techniques was evaluated. OFSP used for the study was sourced from National Root and Tubers Research Institute, Umudike, Nigeria. The experiment was carried out in the Department of Crop Production Laboratory, University of Agriculture and Environmental Science, Owerri, Nigeria. The three different processing techniques used were peeled; scratches peeled, and puree samples. The result of the proximate composition, mineral analysis of the flours and the puree showed significant differences among the samples evaluated. However, the crude protein content for both puree and scratched OFSP was insignificantly different. The puree sample recorded the highest protein content (5.48±0.24) and moisture content (85.95±3.89), respectively, and was closely followed by scratched OFSP with (5.02±0.01) while the least was recorded in the peeled sample (4.03±0.04). The study concluded that scratched OFSP through cabinet drier processing was considered the best alternative to the puree method of storage of orange-fleshed sweet potatoes and the best method of processing in areas where electricity is erratic or not available.

EVALUATION OF BISCUITS PRODUCED FROM WHEAT (Triticum aestivum), TIGER NUT (Cyperus esculentus) AND ORANGE FLESHED SWEET POTATO (Ipomea batatas) FLOURS

Biscuits are ready-to-eat nutritious baked snacks that are available in different shapes and sizes. One of the problems that militate against food security in developing countries such as Nigeria is postharvest loss and underutilization of locally cultivated food crops. This study aimed at evaluating the quality of biscuits produced from wheat, tiger nut and orange fleshed sweet potato flours. Wheat flour was substituted with tiger nut and orange fleshed sweet potato (OFSP) flours for the production of biscuits. While constant 10% tiger nut flour was used in each of the six formulations, the OFSP flour portions were increased from 5 to 30%. A 100% wheat flour served as control. The functional properties of the flours, proximate composition, energy value, vitamin contents, physical and sensory properties of the biscuits were determined using standard methods. The result of the functional properties showed no significant differences (p>0.05) in the bulk densities and gelatinization temperatures of the flour blends. There was significant (p<0.05) reduction in the moisture content of the biscuit samples made from the composite flours compared to the control biscuit sample. Inclusion of tiger nut and sweet potato flour led to increase in the fat, fibre, carbohydrate content and energy values of the biscuit samples. The pro-vitamin A and vitamin C increased as the proportion of orange sweet potato increased and in all the composite biscuits containing tiger nut flour. There were no significant differences (p>0.05) in the thickness, spread ratio and volume of the biscuits. The results of the sensory properties

Functional Properties, Fourier Transform Infrared of Cream and Orange Fleshed Sweet Potato Flour and Sensory Evaluation of Its Dough Meal

ABSTRACT The aim of this study was to determine the functional properties, Fourier-transform infrared (FTIR) properties of cream and orange-fleshed sweet potato flour and sensory evaluation of its dough meal. Three varieties of sweet potato examined were mother’s delight (MDP), king J (KJP) and cream (CFSP). Sweet potato tuber were processed into flour and analyzed for functional, Fourier-transform infrared (FTIR), color, and sensory evaluations. The results show that the packed bulk density ranged from 0.76 to 1.24 g/mL, and water absorption capacity ranged from 32.3 to 56.3 g/mL. It was observed that the FTIR of the flour shows distinctive peak spectra region at 3300, 2900, 1700, 1340 and <1000 cm−1. The percentage solubility and swelling power increase as the temperature increases. Sensory evaluation of the dough meal showed that KJP dough was the most preferred. and it compared favorably with that of the control.

Physiochemical and Sensory Evaluation of Cookies Produced from Composite Flours of Wheat, Bambara Nut and Orange Fleshed Sweet Potato

This study aimed at investigating the use of wheat, Bambara nut and orange fleshed sweet potato composite flours in the production of cookies. Enriched cookies were produced using wheat, Bambara nut and Orange Fleshed Sweet Potato flour blends in the ratios: 100:0:0, 90:5:5, 90:0:10, 80:10:10 and 80:5:15 and were labeled BVB, ACC, LVG, BCN and CFC respectively. Sample BVB (100% wheat flour) served as the control. The functional properties of the flour blends were determined, as well as the proximate and beta-carotene (pro-vitamin A) composition of the cookies. Also, the physical parameters and sensory qualities of the enriched cookies were evaluated. The moisture content, protein, fat, fibre, ash and carbohydrate ranged from 5.70 to 8.57%, 9.62 to 11.93%, 11.02 to 13.02%, 2.33 to 4.03%, 1.23 to 1.54% and 63.33 to 68.79% respectively. The energy value ranged from 405.46 to 420.03 k/cal. There were significant differences (p&lt;0.05) in the functional properties of the flour blends. The result also revealed that the β-carotene (pro-vitamin A) increased with increase in substitution of orange fleshed sweet potato. The results showed significant differences (p&lt;0.05) in physical properties of the cookies in weight, diameter, break strength, density and volume while there were no significant differences (p&gt;0.05) in thickness and spread ratio. The sensory analysis indicated that all the samples had high level of acceptability in their sensory attributes, but sample BVB and ACC had the best overall acceptability ratings of 7.50 and 7.10 respectively. Therefore, enriched cookies produced from the blends were acceptable.

Effect of Feeding Albino Rats with Acha-Orange Fleshed Sweet Potato Blends on the Blood Glucose Level and Hematological Parameters

Aims: To investigate the health and the physiological status of farm animals.&#x0D; Study Design: We formulated seven (7) samples from ACHA and orange-fleshed sweet potato mixture with two (2) samples serving as control.&#x0D; Place and Duration of Study: Department of Food Science and Technology, Faculty of Agriculture and Life Sciences, Federal University Wukari between February 2022 and May 2022.&#x0D; Methodology: The orange fleshed sweet potato flour was mixed with ACHA flour separately at different proportions (100:0, 95:5, 90:10, 85:15, 80:20, 75:25 and 0:100) while one hundred percent (100%) acha flour and orange-fleshed sweet potato was used as the control. Bone meal (10%), blood meal (10%) and salt (5%) were added to each sample. The albino rats were kept in a cage in five (5) segments, and the blends were fed to the rats for 21 days and 100g of the formulated feed were weighed into plates in each segment. The daily weight of the albino rats was measured. Evaluated bioassay parameters including feed and water intake, and body weight. Hematological properties including hemoglobin, red blood cell, white blood cell, mean cellular volume, mean cellular hemoglobin, and mean cellular hemoglobin concentration of the albino rats were also measured.&#x0D; Results: The result of feed intake/weight gain revealed that the rats fed with 0% OFSP showed the highest values for 21 days. The kidney, liver and heart weight of the albino rats decreased from1.23 to 1.05, 5.65 to 2.65 and 1.28 to 0.23g, respectively, while the carcass increased from 104.55 to 111.55g upon OFSP substitution.&#x0D; Conclusion: The result of this study revealed that locally available food commodities such as ACHA and orange fleshed sweet potato can be utilized to produce a protein-rich complementary food capable of combating malnutrition among children. A protein and carbohydrate-rich weaning food comparable to commercial weaning food (cerelac) can be strategically formulated from the blends of ACHA and orange-fleshed sweet potato (75:25).

Cooking quality, nutritional and antioxidant properties of gluten-free maize – Orange-fleshed sweet potato pasta produced by extrusion

Maize and orange-fleshed sweet potato (OFSP) composite (100:0, 50:50, 70:30, 80:20) flours were extruded into pasta using a twin-screw extruder. The cooking quality, textural and nutritional properties of the pasta were assessed. An increase in the proportion of OFSP flour added increased the cooking loss but decreased cooking time and water absorption capacity of pasta. The dietary fibre in the OFSP flour caused a loosening of the compact structure of the pasta, disrupting the compact protein-starch matrix of maize, resulting in higher cooking loss and sticky pasta. Extruded pasta had low cooking time due to pre-gelatinized starch, which promotes greater water absorption and heat dissemination during cooking. Extruded pasta samples had lower beta-carotene, probably due to cis-trans isomerization, fragmentation, and oxidative decomposition, but the pasta showed higher antioxidant properties, likely due to Maillard reaction and caramelization products with reducing properties. These results indicate that OFSP can be composited with maize flour and extruded to produce good quality and nutritious gluten-free pasta.

Development of pearl millet flour-based cookies supplemented with mung bean and orange fleshed sweet potato flours

The study explored the feasibility of producing cookies from pearl millet flour (PMF), mung bean flour (MF) and orange fleshed sweet potato flour (OFSPF). Sixteen formulations were produced by mixing the three basic ingredients: PMF, MF and OFSPF using optimal mixture design of response surface methodology. The sensory properties of cookies developed from these flour blends were evaluated and the result showed variations among cookie samples. Three samples were selected from the optimization results and compared with 100% wheat flour cookies (control). The selected flour blend samples showed a significant (p&lt;0.05) increase in swelling capacity and water absorption capacity. Supplementation with MF improved the protein content of cookie samples while PMF led to an appreciable increase in crude fibre, β-carotene and total phenol contents. This study has confirmed that the production of acceptable cookies of high crude fibre, micronutrients and antioxidant sources that would help reduce the problems of malnutrition and diet-related non-communicable diseases is feasible through the optimization of the basic ingredients.

Development of pearl millet flour-based cookies supplemented with mung bean and orange fleshed sweet potato flours

The study explored the feasibility of producing cookies from pearl millet flour (PMF), mung bean flour (MF) and orange fleshed sweet potato flour (OFSPF). Sixteen formulations were produced by mixing the three basic ingredients: PMF, MF and OFSPF using optimal mixture design of response surface methodology. The sensory properties of cookies developed from these flour blends were evaluated and the result showed variations among cookie samples. Three samples were selected from the optimization results and compared with 100% wheat flour cookies (control). The selected flour blend samples showed a significant (p&lt;0.05) increase in swelling capacity and water absorption capacity. Supplementation with MF improved the protein content of cookie samples while PMF led to an appreciable increase in crude fibre, β-carotene and total phenol contents. This study has confirmed that the production of acceptable cookies of high crude fibre, micronutrients and antioxidant sources that would help reduce the problems of malnutrition and diet-related non-communicable diseases is feasible through the optimization of the basic ingredients.

Development of pearl millet flour-based cookies supplemented with mung bean and orange fleshed sweet potato flours

The study explored the feasibility of producing cookies from pearl millet flour (PMF), mung bean flour (MF) and orange fleshed sweet potato flour (OFSPF). Sixteen formulations were produced by mixing the three basic ingredients: PMF, MF and OFSPF using optimal mixture design of response surface methodology. The sensory properties of cookies developed from these flour blends were evaluated and the result showed variations among cookie samples. Three samples were selected from the optimization results and compared with 100% wheat flour cookies (control). The selected flour blend samples showed a significant (p&lt;0.05) increase in swelling capacity and water absorption capacity. Supplementation with MF improved the protein content of cookie samples while PMF led to an appreciable increase in crude fibre, β-carotene and total phenol contents. This study has confirmed that the production of acceptable cookies of high crude fibre, micronutrients and antioxidant sources that would help reduce the problems of malnutrition and diet-related non-communicable diseases is feasible through the optimization of the basic ingredients.

Nutritional evaluation of complementary porridge formulated from orange-fleshed sweet potato, amaranth grain, pumpkin seed, and soybean flours.

Supplementing breastmilk with poor energy and nutrient‐dense complementary foodstuffs for young children and infants has resulted in malnutrition, poor growth, and retardation of infant development in many sub‐Saharan African countries. Ensuring nutrient adequacy for infants because of their lower consumption requires energy and nutrient‐dense food. In this context, the nutritional composition of porridge from complementary flour blends of locally available foodstuffs (orange‐fleshed sweet potato, pumpkin seeds, amaranth grains, and soybeans) was carried out. Complementary flours formulated from flour blends of pumpkin seeds, extrusion cooked soybean, and orange‐fleshed sweet potato, as well as germinated and extrusion cooked amaranth grains, resulted in varieties of complementary porridges (SAPO1–SAPO5). From these, proximate composition, mineral content (sodium, iron, magnesium, calcium, phosphorus, and zinc), vitamin contents (A and C), and nutrient density of the formulated complementary porridge were determined. Results showed that all the formulated complementary porridge were able to meet the stipulated standards of energy and nutrient (zinc, iron, vitamin A, and protein) densities. Flour blend ratio, germination process, and extrusion cooking significantly (p < .05) influenced the targeted nutrients of interest, as well as the nutrient and energy densities of the formulated complementary porridge. Specifically, the formulated complementary porridge with 40% amaranth grain, 25% orange‐fleshed sweet potato, 20% soybean, and 15% pumpkin seed composite mixture had 76.92% compliance level with recommended standards, which assure adequate nutrient complementation to breastfeeding. The present study provides a valuable insight that complementary foods from locally obtainable foodstuffs are potential solutions for mitigating childhood malnutrition and adequate complementation to breastfeeding by proffering the needed energy and nutrient densities required for the immunity, well‐being, growth, and development of young children and infants, without fortification.

Amino acid, phytochemicals, and antioxidant activities of gluten-free cookies from orange-fleshed sweet potato and Pleurotus tuber-regium sclerotium

This study investigated the amino acid composition, phytochemicals, and antioxidant activities of cookies prepared from blends of orange-fleshed sweet potato and Pleurotus tuber-regium sclerotium. Most of the amino acids of the cookies showed higher values than their corresponding flours. The highest contents of tannins, oxalate, and hydrogen cyanide were found in orange-fleshed sweet potato (OFSP) flour while sclerotium inclusion resulted in increased saponins and alkaloids. Antinutrients of the developed cookies were substantially lower than their corresponding flours. The OFSP flour and cookies showed the highest β-carotene, flavonoids, and phenolic contents. Developed cookies showed higher (p˂0.05) phytochemicals and antioxidant activities than wheat cookies. However, phenolics and flavonoids increased in cookies because of baking while β-carotene and antioxidant activities decreased. This study showed the potentials of OFSP and P. tuber-regium sclerotium composite flour as an alternative food ingredient for protein-enriched functional cookies with potential health benefits.

DEVELOPMENT OF ENRICHED CUPCAKES AND COOKIES WITH ORANGE-FLESHED SWEET POTATO (IPOMEABATATAS L.): SENSORY AND NUTRITIONAL EVALUATION

In developing countries especially in Côte d’Ivoire child malnutrition is a major burden. This malnutrition is often associated with poor nutritional composition of the complementary foods introduced during the weaning period. The purpose of this study was to assess nutritional, microbiological, and sensory properties of cupcakes and cookies supplemented with orange-fleshed sweet potato (OFSP). The proximate and microbiological analysis of enriched products was performed using analytical standard methods. Sensory evaluation of formulated cupcakes and cookies was based on nine-point hedonic scales. Proximate composition showed significant improvements in the contents of ash (1.02±0.06 – 1.98±0.03 g/100g dw), fiber (5.39±0.13 – 7.64±0.47 g/100g dw), and provitamin A (1031 – 4641 mg/100g dw) of enriched cupcakes and cookies compared to control. Based on moderate daily consumption of two pieces of OFSP composite cupcakes (60g/piece) and cookies (44g/piece), children aged 1 to 3 years may cover at least 42 and 85 % of their RDA for vitamin A, respectively. The microbial analysis indicated showed that enriched OFSP cupcakes and cookies were of acceptable microbiological quality. In addition, the enriched OFSP cupcakes and cookies were accepted and liked by the consumers excepted those containing 50% OFSP flour. Thus, cupcakes and cookies formulated with 35% OFSP flour can serve as a valuable vehicle for improving the nutritional status of young children.

Evaluation of maize-based, vitamin A-enriched flat bread from blending ratio of orange fleshed sweet potato (Ipomoea batatas) flour at Arbaminch, Southern Ethiopia

This study was conducted to evaluate maize-based; vitamin A enriched flat breads from orange fleshed sweet potato (OFSP). To enhance vitamin A content of maize based flour, five formulations of flat breads were prepared from blending ratio of 100%(S1), 85:15% (S2), 75:25%(S3), 65:35% (S4) and 55:45% (S5) maize and OFSP flours, respectively. Designs of the study were Completely Randomized for nutritional composition and randomized complete block design for sensory acceptability with 5 treatments and three replications. Sensory acceptability and nutritional compositions of maize-based, vitamin A-enriched flat bread samples prepared from maize and OFSP were evaluated in triplicate. Sample (S5) was most accepted in all sensorial acceptability except color at community level panelists compared with other flat bread samples. The nutritional composition of the flat bread samples showed an increase in the values of crude fiber, moisture, ash and carbohydrate content while the protein, fat and energy content of flat bread were increased as OFSP flours were increased in the formulation. The OFSP and maize flour blends flat bread samples and control sample were observed to have significantly different (p&lt;0.05) in mean scores of vitamin A content. The vitamin A (µg RAE) content of the sample (S1) was 0.00 µg RAE. The vitamin A content was highest (331.60 µg RAE) for the S5 sample. OFSP flour up to 45% can possibly be incorporated in maize-based, flat bread to increase vitamin A content. The moisture content of maize based, vitamin A-enriched flat bread samples are gradual increased with the amount of OFSP flour in blend increased, therefore microbial quality and physical properties of samples will be needed for further research.

Effect of blending ratio of wheat, orange fleshed sweet potato (Ipomoea batatas L.) powder and haricot bean ( Phaseolus vulgarisL.) flour on proximate composition, physical properties and sensory acceptability of biscuits.

Background Protein-energy deficiency (PEM) is still a major health issue in developing countries, and it is the leading cause of disease and death in children under the age of 5 years. Methods 100:0:0; 90:5:5; 80:10:10; 70:15:15; 60:20:20; and 50:25:25 per cent wheat:haricot bean: orange-fleshed sweet potato (OFSP) flours were used to make composite cookies. Standard methods were used to evaluate the proximate structure, physical properties, and sensory assessment. A one-way analysis of variance (ANOVA) model was used to statistically evaluate the data using the statistical analysis system (SAS) software package, version 9.0 standard methods. Results The results showed that partially replacing wheat with haricot bean and OFSP increased the proximate composition significantly. When wheat was replaced with haricot bean and OFSP, the physical characteristics of the biscuits did not vary significantly from those of biscuits made entirely of wheat flour. Sensory acceptability (appearance, color, flavor, taste, and overall acceptability) was higher in the composite biscuits with up to 40% wheat substitution than in the 100% wheat flour biscuits. Conclusions Based on the findings of this report, using OFSP and a haricot bean to wheat flour blend in biscuit formulation appears to be promising in terms of nutritional quality, acceptability, and cost. It is proposed that these products be marketed to vitamin A deficiency (VAD) customers as a newly established product to help mitigate food insecurity.

Physicochemical and microbial properties of orange-fleshed sweet potato flour produced with sun-drying and sulphiting agent

Many local Nigerian processors of sweet potato flour use sun-drying of the sliced roots in place of modern mechanical drying. This study used carotene-rich UMUSPO3 orangefleshed sweet potato (OFSP) variety that was newly bred at National Root Crop Research Institute (NRCRI), Umudike, Nigeria to evaluate the possible effect of sun-drying and sulphiting on the physicochemical and microbial properties of OFSP flour samples. Data were obtained for OFSP sun-dried flour samples processed by different pretreatment methods (blanching, sulphiting with sodium metabisulphite and a control). Results showed that the bacterial and fungal load of the sulphite-flour sample was 8.5×104 CFU/g and 4.00×104 CFU/g while that of the control flour sample was 12.00×104 CFU/g and 6.50×102 CFU/g respectively. The total carotenoid content (TCC) of the flour samples ranged from 10.73 – 11.68 mg/100 g while the TCC of the fresh (unprocessed) OFSP was 40.20 mg/100 g on dry matter basis. The proximate composition of the flour samples was 10.21 – 10.95% moisture, 8.18 – 8.20% protein, 2.40 -2.55% fibre, 0.95 -1.11% fat and 1.73 – 1.85% ash. Obtained physico-functional properties were 13.17 – 13.23 g/mL swelling power, 2.70 – 3.4 g/mL oil absorption capacity, 2.65 – 2.85 g/mL water absorption capacity, 77.50 – 88.000C gelatinization temperature and 0.65 – 0.66 g/mL bulk density

English

Approximately 38% of Tanzanian children have vitamin A deficiency (VAD), and the majority of them do not have access to vitamin A-fortified foods. Orange-fleshed sweet potato (OFSP), a new crop in Tanzania, is rich in β-carotene, and could be a cheaper solution for VAD. The objectives of this study were to develop a type of Ugali (stiff maize porridge) fortified with OFSP, to correlate its β-carotene content (using colour measurement), and to assess its proximate composition and consumer acceptability. Ugali was prepared using maize flour with various amounts of added OFSP (0, 30, 50, 70 and 100%). Samples of Ugali with more OFSP had higher colour values (a* and b*) that imply the increase in β-carotene as the OFSP amount increased. The proximate compositions of Ugali with different amounts of OFSP were different (P<0.05). All samples that were made with the mixture of OFSP and maize flour have shown to have higher sensory scores than those with 100% maize or 100% OFSP; Ugali with 50% OFSP was most favourably rated by Tanzanian consumers. This sample was selected as a potential possibility for everyday consumption since it was shown to potentially supply more than 50% of the RDA of provitamin A for a specific age group. This supplementation method may be simple, affordable, and effective in reducing VAD in Tanzania. Key words: β-carotene, colour parameters, proximate composition, total carotenoids.

Rheological properties of dough and bread quality characteristics as influenced by the proportion of wheat flour substitution with orange-fleshed sweet potato flour and baking conditions

This study investigated the influence of wheat flour substitution with 10–60% of peeled or unpeeled orange-fleshed sweet potato (OFSP) flour on dough rheological properties as well as the effects of the flour mixture, baking temperature (150–200 °C) and time (15–25 min) on the physical and textural properties of the composite bread. I-optimal (combined) design of the Design-Expert software was used for the experimental design whereas the flour mixture and baking conditions for wheat-OFSP composite bread formulation were optimized using the response surface methodology. Significant models were developed where lack-of-fit was insignificant (p > 0.05), coefficient of determination, R2 and adjusted R2 were greater than 0.90 for all response variables of the dough and bread. Farinograph optimum water absorption decreased whereas dough development time increased with increased OFSP flour addition. Moreover, increasing OFSP flour, baking temperature and time significantly (p < 0.05) decreased loaf volume, specific volume, crumb water activity, crust and crumb lightness, crumb springiness, cohesiveness and resilience whereas crust and crumb redness, hardness and chewiness increased. The substitution of wheat flour with 29.4 or 28.0% of peeled or unpeeled OFSP flour, respectively and baking at 180 °C for 15 min produced optimum dough and bread quality characteristics.