Theses and Dissertations
Permanent URI for this collection
Browse
Recent Submissions
Item Open Access Nutritional quality, microstructural properties and consumer acceptability of biscuits obtained from fermented finger millet (eleusine coracana) flours(2022-11-10) Mudau, Masala; Ramashia, S. E.; Mashau, M. E.Finger millet (FM) (Eleusine coracana) is one of the most important minor cereal grains. Its fibre and ash contents are higher than that of major cereals such as wheat and rice. The grains are gluten-free therefore, they should be incorporated in the diet of celiac patients. The objective of this study was to determine the nutritional quality, microstructural properties, and consumer acceptability of biscuits prepared using spontaneously fermented FM flours. The FM grains were fermented at Different period (24, 48 & 72 h) of fermentation. The mineral content of FM flours used in biscuits making, as well as their functional, thermo-pasting, and microstructural properties were investigated. Biscuits were subjected to nutritional quality analyses (proximate composition & minerals), antioxidant, microstructural and sensory properties analyses. The results obtained showed that spontaneous fermentation (SF) decreased the packed bulk density (PBD), swelling capacity (SC), and increased water absorption capacity (WAC), and oil absorption capacity (OAC) of FM flours. The loose bulk density (LBD) values showed that SF had no effect, as no significant differences (p < 0.05) were noted. The LBD, PBD, WAC, OAC and SC of FM flours were within the range of 0.47 to 0.56 g/g, 0.71 to 0.79 g/g, 1.96 to 2.14 g/g, 1.24 to 1.44 g/g, and 13.33 to 14.33 mL, respectively. The cooked paste viscosity of FM flours decreased with increasing period of SF, ranging from 253.67 to 421.67 cP. The process of SF also induced changes in the thermal properties of FM flours as an increment of gelatinization temperatures and gelatinisation enthalpy with increasing time of SF was observed. The onset, peak, and conclusion temperature of FM flours ranged from 69.42 to 82.47 °C, 70.98 to 84.48 °C, and 78.24 to 86.39 °C, respectively. The gelatinisation temperature range and gelatinisation enthalpy of FM flours were within the range of 3.01 to 9.59 °C and 2.99 to 5.07 J/g, respectively. The reduction in the peak viscosity (PV), trough viscosity (TV), and final viscosity (FV) and increment in the breakdown viscosity (BDV), setback viscosity (SV), peak time (Pt), peak temperature (PT) of fermented FM flours were observed. The PV, TV, BDV, FV, SV, PT, and Pt ranged from 1709.67 to 2876.67 cP, 1349.67 to 2739.7 cP, 102.00 to 360.00 cP, 1616.33 to 2959.00 cP, 105.33 to 349.33 cP, 5.11 to 6.80 min, and 74.82 to 75.73°C, respectively. The enhancement in the mineral compositions of FM flours as SF time increased was noted. The microstructural changes in the starch granules as SF time increased were also observed. As for the biscuits, the decrease in moisture, ash, crude fiber, and crude fat contents as well as total phenolic and flavonoids contents as SF time increased was observed. Protein content, carbohydrates content, antioxidant activity, and mineral compositions of FM biscuits increased as SF time increased. The colour attributes such as lightness (L*), showed a significant increase as fermentation time increased in light brown FM biscuits, however dark brown FM biscuits showed no significant differences (p < 0.05). The hue angle and total colour differences (ΔE) iii of FM biscuits increased with increasing time of SF. The reduction in the physical properties of FM biscuits including diameter, weight, spread ratio and an increment in thickness and texture as SF time increased were also observed. The diameter, thickness, weight, spread ratio and hardness of FM biscuits were within the range of 4.54 to 4.76 cm, 0.66 to 0.76 cm, 11.99 to 12.77 g, 6.05 to 7.25 and 689.61 to 2372.23 g, respectively. Spontaneous fermentation also induced changes on the microstructure of FM biscuits. Among the fermented FM biscuits, panellists preferred 24 h gluten-free fermented FM biscuits since they had better sensory properties. Overall, SF enhanced the functional properties, thermo-pasting properties, mineral compositions, and nutritional value of FM flours, as well as the potential health benefits of eating gluten-free FM biscuits.Item Open Access Cassava root (Manihot Esculenta Crantz) characterisation and evaluation of process-induced changes on functional of its flour(2021-06-23) Udoro, Elohor Oghenechavwuko; Jideani, A. I. O.; Anyasi, T. A,Cassava (Manihot esculenta Crantz) is the world’s most important root crop, highly perishable, mostly grown and consumed in the tropics and subtropics of Asia, South America and Africa. Despite the popularity and utilisation of cassava in tropical and sub-tropical regions of Africa, it is not well known in South Africa. In this study, morphological, physicochemical, structural, elemental, and metabolic characterisation was conducted on two South African cassava landraces red (RCLR) and white (WCLR) highlighting their potential end-use properties. Response surface methodology (RSM) was employed in determining the linear, interactive and quadratic effect of varying concentrations of pre-treatment (0.6 – 3.4%w/v) and drying temperature (45 – 74⁰C) on thermal, functional and physicochemical properties of cassava flour (CF) from both landraces. Calcium chloride and citric acid were separately applied in pre-treatment of the flours. Four experimental groups: CF from red landrace pre-treated with citric acid (CAR); CF from red landrace pre-treated with calcium chloride (CCR); CF from white landrace pre-treated with citric acid (CAW); and CF from white landrace pre-treated with calcium chloride (CCW) were comparatively evaluated. In each experimental group, the experimental samples were compared with control samples by One-way ANOVA and separation of means using Duncan Multiple Range Test in SPSS statistics software Version 25 (IBM Corp., New York, USA). Experimental design, analysis, response plots, one-way analysis of variance (ANOVA) of model parameters and process optimisation was done with Stat-Ease design expert software (Version 12). Visual assessment of the root parenchyma showed no distinct features as both landraces appeared cream in colour. However, colorimetric analysis revealed that L* (87.42), a* (0.06), b* (14.17), whiteness (89.45) and brownness index (4.15) of WCLR were significantly different (p < 0.05) from the L* (83.30), a* (0.67), b* (16.07), whiteness (86.50) and brownness index (5.17) of RCLR. Peel thickness of the RCLR (2.27 mm) was significantly higher (p < 0.05) than that of WCLR (1.85 mm) while the percentage flour yield of RCLR (36.15) was significantly lower than WCLR (37.03). Flour from the roots showed significant variance (p < 0.05) in a*, b* and brownness index but the lightness and whiteness index were not significantly different (p > 0.05). Cyanide content (RCLR – 3.62 mg/kg; WCLR – 3.51 mg/kg) of the root was not significantly (p > 0.05) different, but the flour (RCLR – 2.92 mg/kg; WCLR – 1.83 mg/kg) was significantly (p < 0.05) different. Cyanide content of the root and flour were below WHO recommended safe consumption level of 10.00 mg/kg. Scanning electron micrographs of both flours showed spherical and truncated starch granules clustered and dispersed in no regular pattern. Pattern and main peaks (2θ = 43⁰, 23⁰, 17⁰ and 15⁰) of X-ray diffractometry spectra of the flours were the same, exhibiting A-type starch crystallinity. Metabolic profiling, with the aid of gas chromatography-mass ii spectrometry, revealed that phenolic acids identified were higher in WCLR than RCLR. A reverse trend was observed with identified FAMEs in the landraces. Of all sugars identified, sucrose had the highest concentration in both landraces. X-ray fluorescence spectrometry of CF revealed that both landraces contained potassium (RCLR - 26.10 mg g−1; WCLR – 30.30 mg g−1), magnesium (RCLR – 23.40 mg g−1; WCLR – 16.80 mg g−1), calcium (RCLR – 11.50 mg g−1; WCLR – 5.60 mg g−1), aluminium (RCLR – 1.50 mg g−1; WCLR – 1.50 mg g−1), phosphorus (RCLR – 0.80 mg g−1; WCLR – 1.50 mg g−1), iron (RCLR – 0.50 mg g−1; WCLR – 0.50 mg g−1), chromium (RCLR – 0.20 mg g−1; WCLR – 0.20 mg g−1), and titanium (RCLR – 0.20 mg g−1; WCLR – 0.20 mg g−1). Differential scanning calorimetry showed that pre-treatment had an increasing effect on the gelatinisation temperatures and enthalpy of CF. Citric acid treatment had a decreasing effect on water holding capacity of CF when compared to calcium chloride. Loose bulk density (LBD) ranged between 0.34 – 0.41 g/cm3 (CAR), 0.37 - 0.45 g/cm3 (CCR), 0.35 – 0.43 g/cm3 (CAW) and 0.37 – 0.44 g/cm3 for CCW respectively. The LBD increased with an increase in DT. Packed bulk density (PBD) of CF treated with calcium chloride and citric acid were similar with the least and highest PBD of 0.62 and 0.73 g/mL respectively. An increase in drying temperature and concentration increased ash content. Calcium chloride and citric acid pre-treatments improved the lightness and whiteness index of CF. The L* values of CF were between 91.37 and 93.65 with the control (not pre-treated) samples significantly lower (p < 0.05) than the experimental samples in all four groups. The study reveals that the pre-treatments have a mitigating effect against enzymatic browning associated with cassava root processing. An increase in thermal properties indicates that the processing conditions confer on CF more stability in the presence of heat and water. Chemical characterisation shows that both landraces are of the sweet type, with low cyanide content which makes them safe for human consumption. The flours contain minerals that are useful for proper body function and metabolism. The A-type starch crystallinity of flour exhibited, positions the flours as a suitable wheat replacement in flour-based food applications. Therefore, the roots of these landraces can be processed into minimally processed foods such as chips. The flours can be utilised in food applications such as baked products, gels and stabilisers.Item Open Access Extraction and characterization of pectin from prickly pear (Opuntia spp.) peel(2020-08-24) Lekhuleni, Isobel Lerato Gosh; Jideani, A. I. O.; Kgatla, T. E.; Mashau, M. E.The study aimed to determine the physicochemical properties, extract and characterise pectin from three varieties (green, purple and orange) of prickly pear (Opuntia spp) fruit peel. Research samples were collected from Bothlokwa Mphakane village in Limpopo province of South Africa. The experimental design for this study was randomized complete block design and each treatment was conducted in triplicate. Pectin was extracted using sulphuric acid at four different pH levels (1, 2, 3 & 4) and microwave power levels (low, medium & high). The characterisation of extracted pectin was done by calculating the ash, moisture, equivalent weight, anhydrouronic acid, methoxyl content, and degree of esterification. Functional groups present in extracted and commercial pectin were investigated for similarities using Fourier Transform Infrared Spectroscopy. The yield of pectin for purple ranged from 2.9% to 13.8%, orange from 1.4% to 9.8% and from 2.3% to 10.0% for green prickly pear peel. A decrease in pH resulted in an increased pectin yield and an increase in microwave power level increased the pectin yield. Maximum yields of 13.8% on purple, 10.0% on green and 9.8% on orange were obtained at pH 1.0 and medium power level. The best condition for extraction using sulphuric acid was at a medium power level and pH 1.0. The pectins obtained were compared against each other in terms of yield, physicochemical characteristics and chemical structure. The ash content of the extracted pectin was significantly higher at 25.16 ± 0.69, 34.26 ± 1.92 and 36.30 ± 1.07, however the pectin showed lower moisture content and equivalent weight. The methoxyl contents were 2.28 ± 0.26, 2.38 ± 0.21 and 3.86 ±0.31, anhydrouronic acid contents were 25.58 ± 2.03, 25.93 ± 2.35 and 38.84 ± 2.29, and degree of esterification were 49.87 ± 0.17, 50.63 ± 4.76 and 56.39 ± 1.60 across the orange, purple and green varieties, respectively. The prickly pear peel pectin spectra exhibited similarities in its absorption pattern to that of commercial citrus pectin. Therefore, the extraction of pectin from prickly pear peels is feasible in viewpoint of yield and quality, and that the pectin has potential for substitution of citrus pectin in the food processing industry.Item Open Access Oil distribution, microstructure and in vitro starch digestibility of bran-enriched magwinya(2020-09) Onipe, Oluwatoyin Oladayo; Jideani, A. I. O.; Beswa, DanisoMagwinya, a cereal fried dough, is a popular traditional snack widely consumed across various ethnic groups in Sub-Saharan Africa, but little is known about its production and consumption in a scholarly context. Furthermore, its oil distribution, starch digestion and microstructure have not been documented. It is against this background that this research was carried out. Firstly, a survey of the production process, ingredient formulation, sales, characteristics and consumption of magwinya in Thohoyandou were investigated. Out of the 30 magwinya production sites visited and 650 consumer questionnaires distributed, data were obtained from 29 sites and 634 consumers: a response rate of 97% and 98%, respectively were realised. Results revealed, details on the formulation, ingredients, processing methods, sales, consumption patterns and consumer preference of magwinya; and proposed considerations for the development of a healthier magwinya. Cake wheat flour (55%) was the main ingredient used. Production process was non-automated as evidenced by manual mixing and fermentation processes (93%), coupled with low usage of electronic equipment (14%). With a daily turnover between ZAR500 – ZAR3000 ($35 - $210), there is a need to improve magwinya production through an automated production line, especially for large-scale producers of this product. The daily turnover indicated that magwinya production is a lucrative business contributing immensely to the livelihoods of, and financially empowering the producers, who were all females (100%). Consumer data revealed magwinya to be a moderately liked food (46%) consumed at least twice a week (32%), as either a snack or main meal; with taste as the most favoured characteristic (79%). About 93% of consumers fell within <20 and 21-30 age groups. A greater percentage of consumers (75%) disliked the oiliness of magwinya, and with increasing awareness of the health implications of frequent consumption of fried foods; 87% of consumers affirmed purchase of low-fat magwinya if made available. Development of low-fat, nutrient-rich magwinya is therefore recommended to offer consumers a healthier variety. The experiments in this study were constructed using a 2x2x7 factorial experimental design. Factors considered were two (2) bran types - wheat and oat bran; two (2) product types and seven (7) bran amounts (0, 1, 5, 8, 10, 15 & 20 g/ 100 g). Oil fractions of the total oil content of magwinya was categorized as surface oil (SO), penetrated surface oil (PSO) and structural oil (STO) using spectrophotometric method. Moisture loss reduced (P < 0.05) from 23.35% in control to 15.19% fried batter with 20% oat bran (OB), while a reverse trend was observed in fried dough. Reduction of total fat from 0.43 g/g in control to 0.38 g/g at 20% OB and 8 g wheat bran (WB) was observed. At 15% OB and 20% WB, total fat reduced from 0.41 g/g in control to 0.26 g/g of FD. An STO0.70. Confocal microscopy and image analysis were effective in measuring oil absorption and interpreting crumb properties of fried dough. Glucose, starch fractions and estimated glycemic index (eGI) of bran-enriched magwinya were estimated using in vitro starch digestion assay. Rapidly available glucose (RAG) of control fried dough (60.31 g/ 100 g) product was 33% less than fried batter (90.07 g/ 100 g) and more unavailable glucose (UG) less than fried batter. OB and WB significantly reduced RAG and increased UG of fried products. However, OB showed about 9% more reduction than wheat bran. A similar trend was observed for rapidly digestible starch and resistant starch of fried products. The eGI results showed control fried batter to be a high GI food (eGI = 80.02) and control fried dough to be medium GI food (eGI = 58.11). WB fried dough, fried batter and OB fried dough can be categorised as medium GI foods at eGI of 56.46 – 58.39, 65.93 – 68.84 & 56.34 – 57.27 respectively; while OB fried batter at 73.57 – 80.03 as high GI foods. RS showed negative significant correlation with eGI (r= - 0.866, -0.932, P < 0.01) and fat content (r = -0.618, - 0.671, P < 0.01) for OB and WB fried products. Finally, the distribution of chemical components of magwinya were visualised using NIR hyperspectral imaging (HSI). Principal component analysis (PCA) was applied to mean-centred data for pixel-wise classification using spectral scattering (standard normal variate) and 1st and 2nd derivatives of Savisky-Golay method. There was little separation observed in the PCA score plots in the results due to a large similarity between classes. Prominent bands related to oil were featured at 1400, 2305 and 1716 nm, while those related to starch were featured at 1449, 1776, and 2261 nm. 1941 (related to moisture), and 2117 nm (related to protein). Bands related to protein were featured at 1509, 1994, 2223, 2229 nm and water at 1450, 1934 and 1940nm. Aromatics, phenols (1422 nm) and benzene were also identified, albeit minimum. The processing methods and some principal components assisted in mapping the chemical components of magwinya. Visualisation of magwinya chemical constituents using HSI shows good promise for further research in modelling and predictions. The protocols for oil distribution measurement and CLSM used herein can be applied to other thick deep-fried products for qualitative observation and quantitative measurement of specific physical or chemical property. These results reveal that ingredient modification and processing is effective for oil uptake reduction, regulation of starch digestion and related eGI of deep-fried dough/ batter foods.Item Open Access Influence of head-moisture treatment on functional, colour and thermal properties of bambara ground-nut starch(2019-09-20) Mathobo, Vhulenda Melinda; Silungwe, Henry; Ramashia, ShonisaniHeat-moisture treatment (HMT) is a physical modification that alters the physicochemical properties of starch without changing its molecular structure. The objective of the study was to investigate the influence of HMT on the functional, colour and thermal properties of bambara groundnut (BG) starch. A central composite rotatable design comprising two independent factors (temperature and time) was used for the study. The central composite rotatable design was generated using Design-Expert software version 8.0.1.0. Bambara starch extraction was done by milling BG into flour (5 Kg), suspension in 15 L, 0.3% sodium hydroxide and centrifugation followed by washing using distilled water. The starch was then HMT treated in an air oven at 80 - 120 °C for 30 - 90 min under 15 % moisture content (MC) (HMT 15), 25% MC (HMT 25) and 35% MC (HMT 35). The highest L* and WI values for HMT treated BG starch were observed at HMT 80 °C for 30 min under 15% MC; 100 °C for 60 min (25% MC); and 100 °C for 17.57 min (35% MC) while the lowest was observed in HMT 100 °C for 102.43 min (15% MC); 120 °C for 90 min (25% MC); and 120 °C for 90 min (35% MC). In HMT 15-BG starch, the gelatinisation parameters onset (To), peak (Tp) and concluding temperature (Tc) of the samples decreased as treatment time and temperature increased whereas gelatinisation enthalpy of BG starch increased with increase in HMT treatment temperature and time. In HMT 25-BG starch Tp, and gelatinisation enthalpy of the starch increased with increase in HMT treatment temperature and time. While in HMT 35-BG starch, To, Tp, Tc and gelatinisation enthalpy of the starches decreased with increase in HMT treatment temperature and time. In HMT 15-BG starch, the water absorption capacity (WAC), solubility and swelling power (SP) decreased as treatment time and temperature increased while oil absorption capacity (OAC) of the starch increased with increase in HMT treatment temperature and time. In terms of HMT 25-BG starch, the WAC and OAC increased as HMT treatment time and temperature increased while SP and solubility of the starch decreased with increase in HMT treatment temperature and time. In HMT 35-BG starch, OAC, solubility and SP decreased as treatment time and temperature increased while WAC of the starch increased with increase in HMT treatment temperature and time. The optimum HMT conditions for BG starch were found to be 80 °C for 30 min (HMT 15), 105.74 °C for 30 min (HMT 25), and 113.16 °C for 30 min (HMT 35). Desirability of the obtained optimum conditions were 0.63 (HMT 15), 0.56 (HMT 25) and 0.64 (HMT 35). Information obtained from scanning electron micrograph indicates oval and round shape for bambara starch granules, with varying sizes. The range of the granule size width was 4.2 – 4.7 mm and 10 μm for length. The modified starches showed some changes in granule morphology as they seem to disintegrate with application of HMT. Unmodified and HMT - BG starches showed characteristic FTIR bands linked with common starches. All the samples displayed complex vibrations in the region below 1000 cm-1 due to the skeletal vibrations of the glucose pyranose ring. Statistical analysis on colour, thermal and functional properties of HMT 15-BG, HMT 25-BG and HMT 35-BG starch showed that effects of temperature and treatment time had no significant (p ≥ 0.05) effect on these properties of HMT-BG starch. However, treatment time had a significant linear effect (p ≤ 0.05) on swelling power, for HMT 15-BG starch. In HMT 35-BG starch, WAC was significantly affected by quadratic effect of temperature and time while solubility was significantly affected by linear effect of time and quadratic effect of temperature.Item Open Access Effects of maturity and processing on quality properties of the watermelon (Citrullus lanatus) fruit juice(2019-05-17) Maoto, Makaepea Mossa; Jideani, A. A. O/; Beswa, D.Watermelon (Citrullus lanatus) juice is rich in phytochemicals that possess antioxidant properties which are known to have a positive contribution to human health. Colour, pH, total soluble solids, lycopene, β-carotene, ascorbic acid, total polyphenolic content and antioxidants activity are quality properties that characterise watermelon juice. However, these quality properties undergo some chemical changes throughout the stages of maturity of the fruit as well as during thermal processing. The aim of this study was to investigate the effects of maturity and filtration on the physicochemical properties (colour, pH, total soluble solids) and the phytochemicals (lycopene, β-carotene, ascorbic acid, total polyphenolic content and antioxidants activity) of fresh watermelon juice. It further investigated thermosonication effects on these quality properties using response surface methodology (RSM). RSM considering temperature (25 – 52ºC), time (2 – 10 min) and amplitude level (24.1 – 60 μm) at a constant frequency of 20 kHz were the independent variables while colour variables (L*, a* and b*, C* and h*), pH, total soluble solids, lycopene, β-carotene, ascorbic acid, total polyphenolic content and antioxidants activity were the dependent variables. Results showed that colour, pH, total soluble solids, lycopene, β-carotene, ascorbic acid, total polyphenolic content and antioxidants activity of watermelon fruit juice are maturity dependent. All the physicochemical and phytochemical properties increased with maturity. The combination of the CIELAB parameters (L*, a*, b*) was clearly explained by the Chroma (C*) and hue (hº). The (C*) and hº values of the watermelon fruit juice were significantly (p < 0.05) affected by the stages of maturity. The red colour was observed to be more saturated in the fully - ripe sample as indicated by the highest Chroma (7.35) values. The half - ripe sample which was observed to be pink - red had a C* of 5.88 while the lowest (4.32) value was observed from the unripe sample. The highest hº value was obtained from unripe sample (83.89), while lower value was observed from the fully - ripe (76.03) sample because of the saturation of the red colour in the fully - ripe sample. The total soluble solids also increased with stages of maturity 6.66 to 6.60 at half - ripe while at fully - ripe redness changed from 9.3 to 8.99 and TSS 8.37 to 8.02. Filtration has shown a significant (p < 0.05) on the C* and hº values. There was a higher retention of all dependent variables at lower thermosonication treatment (25ºC; 24.4 μm), especially the lycopene which increased by 127%. Model predictions for the colour properties and phytochemicals were closely correlated to the experimental results obtained. Prediction models were found to be significant (p < 0.05) with low standard errors and high coefficients of determination (R2).Item Open Access Physical, functional and nutritional properties of flours from finger millet (Eleusine coracana) varieties fortified with vitamin B₂ and zinc oxide(2018-09-21) Ramashia, Shonisani Eugenia; Jideani, A. I. O.; Gwata, E. T.; Meddows-Taylor, S.Finger millet (FM) (Eleusine coracana) grains are the staple food in Africa and India for communities with low socio-economic growth. The grains have high content of calcium, dietary fibre, carbohydrates that are rich in protein, fat, iron, phosphorus, vitamin and essential amino acids. Flours from milky cream (MC), brown and black varieties of FM were fortified with vitamin (vit) B₂ and zinc oxide (ZnO) in order to restore the nutrients that were lost during milling and sieving processes. The main aim of the study was to analyse the physical, nutritional composition and functional properties of flours from three (3) FM varieties fortified with vit B2 and ZnO. Pearl millet was used for comparison with the results obtained from this study. MC, brown and black varieties of FM flour treatments were arranged as a completely randomized design (CRD) in three (3) replicates. Physical properties: dimensional properties, colour attributes, kernel weight, bulk density (BD), true density, porosity, surface area, kernel volume, aspect ratio, sphericity and moisture content of the FM grains were analysed. Vitamins and minerals were also analysed. Functional properties: colour attributes, bulk density (BD), water absorption capacity (WAC), oil absorption capacity (OAC), swelling capacity (SC), swelling index (SI), foaming capacity (FC), foaming solubility (FS), dispersibility (Dis), viscosity (cool & hot paste), pasting properties, thermal properties and microscopic structure of FM flours were determined. Data generated were analysed using SPSS version 23.0. Moisture content of MC FM grain and flour was significantly higher (p < 0.05) than brown and black varieties but was within the specified range of <12%. This indicated the long storage shelf-life of the grains and flours. Length of brown FM grains was significantly higher (p < 0.05) when compared to MC and black varieties. MC variety was significantly higher than other varieties in width, kernel weight, bulk density, true density, aspect ratio and sphericity. The information obtained from this study will help in designing suitable equipment for planting, harvesting, storage, processing and packaging of grains. Pearl millet grain was significantly higher than FM flours in all physical properties. MC FM was significantly higher iii in L* (whiteness/ brightness), b* (yellowness/ blueness), C* (chroma), Hº (hue angle) and ZnO values compared to brown and black flours. MC raw fortified finger millet (RFFM) and instant fortified finger millet (IFFM) flours were significantly higher in vitamin B2. People prefer fortified MC flour because most of people living in South Africa use white maize as their staple food and it is similar to MC. Colour is the most important quality parameter in food processing industries and it is also attracts the consumer’s choice and preference. The vitamins and minerals that were lost during sieving, drying and milling were replaced by the two (2) fortificants added which may help to reduce the micronutrient deficiencies. Milky cream FM flours showed significantly high (p < 0.05) values in BD, WAC, OAC, SI, FC and dis. These are the fundamental physico-chemical properties that reflect the interaction between the composition and molecular structure. Length of brown FM grains was significantly higher (p < 0.05) when compared to MC and black variety. The MC variety was significantly higher than other varieties in width, kernel weight, bulk density, true density, aspect ratio and sphericity. Pearl millet was significantly higher than FM flours in all physical properties. MCFM variety was significantly higher in L* (whiteness/ brightness), b* (yellowness/ blueness), C* (chroma), and Hº (hue angle) values as compared to other FM varieties. Moisture content of MC flour was significantly higher as compared to brown and black FM flours. Pasting properties of MC raw finger millet (RFM) and RFFM flours showed significantly higher in peak viscosity (PV) (3518 cP), final viscosity (FV) (6554 cP), breakdown viscosity (BDV) (703 cP) and setback viscosity (SV) (3868 cP) as compared to other RFM and RFFM flours. Brown instant finger millet (IFM) and IFFM flours had significantly higher of PV (723 cP), trough viscosity (TV) (655 cP) and FV (983 cP). IFFM flours had significantly higher values of PV (712 cP), TV (614 cP) and FV (970 cP), respectively. The instant pearl millet (IPM) and instant fortified pearl millet (IFPM) showed significantly higher value in BDV (330 cP and 131 cP) and SV (362 cP and 346 cP), respectively. Thermal properties of black RFM was significantly higher in onset temperature (To) (74.31), peak temperature (TP) (81.94ºC) and conclusion temperature (Tc) (89.64) and RFFM starches were significantly high in To (81.80ºC), TP (84.22ºC) and TC (92.81ºC), respectively. Milky ivcream IFM starch showed significantly higher values in TO (84.57ºC), TP (87.27ºC), Tc (92.81ºC) and ΔH (7.63ºC) compared to other starches. Brown IFFM flour was significantly higher value in To (85.88ºC) and TP (87.14ºC). The starch of IFPM was significantly higher in enthalpy of gelatinisation (6.91ºC) and PHI (2.94ºC) as compared to other FM starches. Brown IFM flour showed significantly higher value in gelatinisation temperature range (13.50ºC). The microscopic structure revealed that RFM and RFFM flours had oval and smooth surfaces. RFM and RFFM flours showed positive effect after fortificants were added because the starch granules, protein bodies and protein matrix were visible and formed crystal. IFM and IFFM flours had some holes, dents and rough surfaces. Instant fortified flours showed negative effect after fortificants were added due to technological processes such as recooking and remilling of flours. Different variations observed on physical, nutritional and functional properties after adding the fortificants may affect the physical, chemical and organoleptic properties of food produced from fortified flour. There is need to fortify FM flours with ZnO which may help to replace the value lost during milling and sieving operations. It is possible that the availability of ZnO could reduce the incidence of some non-communicable diseases.Item Open Access The effect of malting and fermentation on the nutritional and potential health-promoting properties of finger millet [Eleusine coracana (L.) Gaertn] grain(2018-09-21) Udeh, Henry Okwudili; Jideani, A. I. O.; Duodu, K, G,Finger millet (FM) [Eleusine coracana] is an underutilised cereal grain used as a food source in South Africa. Increased research interest in FM has span over the years owing to its unique nutritional and bioactive composition. Following the recent interest in natural curative substances over their synthetic counterparts in the treatment of food dependent diseases, FM has shown potential nutraceutical effects. Some important health effects like antidiabetic, antioxidative, anti-inflammatory and antimicrobial properties have been reported in recent trials with FM. In view of the increasing utilisation and application of FM in the region of Thulamela Municipality, Vhembe District of South Africa, two common indigenous FM varieties (brown and dark brown) were obtained and analysed for their physicochemical properties, levels of minerals, phytic acid, phenolic compounds and antioxidant activities. For this process, malted non-alcoholic beverages were produced and analysed for their physicochemical properties, levels of phenolic compounds, and total phenolics and antioxidant activities. FM grains were soaked, germinated and kilned at an interval of 24 h for 96 h, using sorghum as an external reference. Mineral composition of the FM and sorghum samples were analysed using an inductively coupled plasma atomic emission spectroscopy (ICP-AES) and mass spectroscopy (ICP-MS), and atomic absorption spectrometer (AAS). Identification and quantification of phenolic compounds were performed using ultra-performance liquid chromatography mass spectrometer (UPLC-MS). All experiments were performed in triplicate except for the UPLC-MS analysis of the malted non-alcoholic beverages that was done in duplicate. Data were analysed by one way analysis of variance, and the mean values were separated by Duncan’s multiple comparison test using SPSS version 24.0. Data showed that the FM varieties were rich in macro- and micro- or trace elements. The macro-elements calcium, magnesium, potassium, phosphorus and sulphur were found in high amounts ranging from 1597.37 mg/ kg – 6775.03 mg/ kg; iron, zinc, strontium and silicon were found in significant amounts in the range 21.47 mg/ kg – 55.67 iii mg/ kg, copper and boron were found in low amounts (2.2 mg/ kg – 7.7 mg/ kg), along with selenium and cobalt (0.02 mg/ kg – 0.05 mg/ kg). Heavy metals, barium and aluminium were found in the FM varieties. Varietal difference was found to play an important role in the mineral content of the grains during malting. Malting for 24 h reduced mineral content except for sodium. Beyond 48 h of malting, mineral content increased, particularly, for 96 h in FM grain malt. Significant (p < 0.05) increases in the mineral content of FM varieties were noted at 48 h and 96 h of malting. Increase occurred at 72 h of malting for potassium, iron and boron. Malting did not have any effect on the manganese content of the dark brown FM; however, it increased the manganese content at 48 h of malting for brown FM. Malting for 96 h significantly (p < 0.05) reduced sodium content. Consecutive decrease in phytic acid content of the grains was not recorded with durations in malting time. Although statistically significant differences (p < 0.05) were observed, malting did not result in too much change in the physicochemical properties of the grains. Several flavonoids, catechin, epicatechin, quercetin, taxifolin, and hesperitin were isolated, whilst protocatechuic acid was the only phenolic acid detected in the unmalted and malted FM. Increases in catechin, epicatechin and protocatechuic acid were observed for 72 and 96 h malt of brown FM with similar observations recorded for sorghum. Complete loss of taxifolin, catechin, and hesperitin were noted with malting time. FM grains exhibited 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2՛-azinobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging action and iron reducing activities. Increased iron reducing activity alongside ABTS radical scavenging activity was recorded with malting time. A fermentation-time dependent decrease in the pH of the non-alcoholic beverages, with a corresponding increase in sugar content were recorded. A similar decrease was also recorded for the viscosities of the beverages. The FM malt beverages were found to contain a higher amount of citric acid compared to the sorghum malt beverage. A decrease in the citric acid content with fermentation time was noted in the grain malt beverages fermented with Lactobacillus fermentum, particularly for the iv FM beverage. The phenolic compounds detected in the FM malt beverages fermented with the grain microbial flora and Lactobacillus fermentum were protocatechuic acid, catechin and epicatechin. Taxifolin and kaempferol along with the earlier mentioned compounds were detected in the sorghum malt beverage. Catechin was found in higher amount compared to other phenolic compounds in the FM and sorghum malt beverages. FM malt beverages were found to contain a higher amount of total phenolics compared to the beverage prepared from sorghum malt. Fermentation with the grains’ microbial flora and L. fermentum resulted in reduced total phenolics of FM and sorghum malt beverages, particularly after 24 h of fermentation. A fermentation-time dependent decrease in total phenolics of FM beverages fermented with L. fermentum was noted. Fermentation within 24 - 48 h using the grain microbial flora showed higher total individual phenolic compounds for the dark brown FM and sorghum, compared to other fermentation periods. Fermentation of the beverages for 24 h retained a higher amount of the total phenolics compared to other fermentation periods, especially for the L. fermentum beverages. Reduced total phenolic content and antioxidant activity of the beverages were noted at 24 h of fermentation for the two microbial sources. Significant (p < 0.05) increases in total phenolics were observed within 72 – 96 h of fermentation of the brown FM malt beverage with the grains’ microbial flora. Fermentation for 72 h and 96 h with L. fermentum increased the total phenolic content of the brown FM. Increase in total flavonoid content (TFC) of brown FM malt beverage was noted at 72 h fermentation for both microbial sources. Unlike with L. fermentum, no significant (p > 0.05) change in TFC was observed for the dark brown FM beverage after 24 h fermentation with the grains’ microbial flora. Beverages exhibited DPPH, ABTS radical scavenging action and iron reducing activities, which were significantly (p < 0.05) reduced at 96 h fermentation for both microbial sources. The 24 h fermented beverage retained a higher amount of total phenolic and flavonoid contents, and had higher antioxidant activity compared to other fermentation periods for both microbial sources. The study shows that FM is a rich source of essential minerals and v phenolic compounds, and demonstrates that 72 to 96 h of malting has a positive effect on minerals and certain phenolic compounds over the 48 h malting period widely used for preparation of FM malt. The presence of hesperitin in FM grain was established. A new method was developed for the production of FM non-alcoholic beverage with measurable amounts of health-promoting compounds. An ideal fermentation period (24 h) for FM malt non-alcoholic beverage production with enhanced health-promoting compounds, using Lactobacillus fermentum was demonstrated. Fermentation limit (96 h) for production of FM malt beverage using either the grain microbial flora or L. fermentum was confirmed. These findings provide a rationale for increased utilisation of FM as a functional food grain, and its use as malt in production of non-alcoholic beverage for health promotion and wellness.Item Open Access The effect of Moringa Oleifera leaves and termite (Isoptera) powders on nutritional and sensory properties of an instant-maize porridge(2017-09-18) Netshiheni, Khavhatondwi Rinah; Jideani, A. I. O.; Beswa, D.; Mashau, M. E.White maize-based porridge is a staple food for about 80% consumers in South Africa and sub-Saharan African countries contributing significantly to the diet of rural populations in developing countries. White maize is deficient in some amino acids and over-dependency on its porridge may lead to high prevalence of malnutrition-related health conditions. Moringa oleifera (MO) and termite (Isoptera spp.) are known to contain a substantially high amount of protein. The aim of this study was to determine the effect of powders from MO leaves and termite on the nutritional and sensory properties of instant-maize porridge. Inclusion of MO and termite powders in instant-maize porridge, at different treatments, was considered using a completely randomised design. Factor levels were: AOB-control (maize flour); BEA (maize, powders of cooked dried MO and termite); CIA (maize, powders of blanched dried MO and termite) and DJE (maize, powders of uncooked dried MO and termite). Data were analysed using SPSS version 23. The protein content of fortified instant-maize porridge (FMP) significantly (p < 0.05) increased from 10.02 to 21.20% compared to unfortified porridges. The mineral content of FMP was higher in terms of Zn, Fe, Ca and Mg. Moisture content of FMP increased from 5.00 to 6.00%. Sensory analysis showed that among fortified porridges, CIA was rated high for colour and texture, BEA higher in taste and DJE higher for aroma. AOB had higher acceptance than fortified porridges for taste. Powder from MO leaves and termite could be used in complementary foods and food supplements to increase protein and mineral contents.Item Open Access The effect of oven and microwave drying methods on the drying kinetics and physical properties of two banana vatieties in Limpopo Province, South Africa(2016-02-02) Omolola, Adewale Olesegun; Jideani, I. O.; Kapila, P. F.Item Open Access Nutritional profiling and effects of processing an unripe banana cultivars in Limpopo Province, South Africa(2016-02-01) Anyasi, Tonna Ashim; Jideani, A. L. O.; Mchau, G. R. A.Item Open Access Assessment of antibiotic resistance phenotypic patern in some commensal bacteria isolated from meat and dairy products(2015-02-18) Moyane, Jeremia Ntambama; Jideani, A. I. O.; Aiyegoro, O. A.Item Open Access Shelf-life extension of home-made mahewu by adding Aloe vera powder(2015-02-12) Mashau, Mpho Edward; Jideani, A. I. O; Maliwichi, L. L.Item Open Access Effects of mineral ions on yeast performance under very high gravity beer fermentation(2015-02-11) Udeh, Henry Okwudili; Kgatla, T. E.; Jideani, A. I. O.