A comparison of the ability of several small and large deformation rheological measurements of wheat dough to predict baking behaviour

The rheological characteristics of twenty wheat flour samples obtained from four organic flour blends and a non-organic control were compared in relation to their ability to predict subsequent loaf volume in the baked bread. The flour samples considered had protein contents that varied between 11–14 g/100 g. Four different rheological methods were employed. Oscillatory stress rheometry on the protein gel extracted from the wheat flour, oscillatory stress rheometry and creep measurement on undeveloped dough samples and biaxial extensional measurements on simple flour–water doughs. None of the fundamental rheological parameters correlated with loaf volume. There was a correlation between the storage modulus of the gel protein and storage modulus for the undeveloped dough (r = 0.85). There was a weak negative correlation between protein content and biaxial extensional viscosity (r = −0.62). Stepwise multiple regression related loaf volume to dough stability time (measured on the Farinograph) and tan (phase angle) for the undeveloped dough samples (overall model r² = 0.54). The results indicate that the four rheological tests considered could not be used as predictors of subsequent loaf volume when the bread is baked.     

Influence of water and barley β-glucan addition on wheat dough viscoelasticity

The effects of the addition of two barley β-glucan isolates (0.2–1.0% of wheat flour), differing in molecular weight, and water (53–63% in a poor breadmaking wheat flour, cv. Dion, and 58–68% in a good breadmaking wheat flour, cv. Yekora) on the viscoelastic properties of wheat flour doughs were investigated. A response surface model (CCF) was used to evaluate the effects observed on the dynamic and creep-recovery parameters of the dough. The evaluation was done separately for each combination of β-glucan isolate (BG1 of ～10⁵ Da and BG2 of ～2 × 10⁵ Da) and flour type. Besides the contents of β-glucan and water, the molecular size of the polysaccharide and the flour quality were important determinants of the dough’s viscoelastic behavior. Compared to BG1, the higher molecular weight β-glucan (BG2) brought about major changes on all the rheological responses of the fortified doughs. The addition of appropriate levels of β-glucans and water in the poor breadmaking cultivar (Dion) doughs could yield similar viscoelastic responses to those observed by a non-fortified good breadmaking quality flour dough (Yekora).     

Effect of Lactobacillus brevis-based bioingredient and bran on microbiological,physico-chemical and textural quality of yeast-leavened bread during storage

The effects of wheat bran and of a Lactobacillus brevis-based bioingredient (LbBio), obtained after growth in flour-based medium, on quality of yeast-leavened wheat bread (WWB) were investigated. Bran was used in bread formulation by substituting a part (20 g/100 g) of white wheat flour (WBB), while LbBio was used instead of the water content (WWB + LbBio and WBB + LbBio). The use of LbBio in WWB resulted in the biological acidification of the dough due to lactic, phenyllactic and OH-phenyllactic acid contents determining a high fermentation quotient value and an improved bread texture and microbiological quality. Conversely, wheat bran reduced the specific volume and crumb hardness during storage at 25 °C, and affected the antibacterial ability of LbBio during 30 °C storage. Our findings demonstrated that LbBio counteracted the negative effects of bran and allowed to obtain an enriched fibre bread with specific volume and soft crumb comparable to bread without bran.Industrial relevanceBread is a perishable food with a short microbiological and physico-chemical shelf-life. The main microbiological alteration occurring into few days after baking is the “rope spoilage” caused by spore-forming bacteria originating from raw materials. This phenomenon, often misinterpreted as a sign of unsuccessful dough leavening and not visible from outside, is more common under industrial production conditions during the hot season causing large economic losses in the warm climates of Mediterranean countries, Africa and Australia. The use of sourdough often controls this alteration even if the industrial application of this traditional process is limited by the long leavening times. In this study, an innovative procedure for the preparation of yeast-leavened bread comprising the addition of a fermentation product from Lactobacillus brevis grown in a flour-based medium has been applied. The resulting fermentation product (LbBio bioingredient) acts as a sourdough acidifying the dough and improving the textural, physico-chemical and microbiological properties of the resulting bread. The application of bioingredient LbBio could represent an innovative strategy in industrial bread production to obtain acidified yeast-leavened products, thus, preventing the ropy spoilage and reducing the negative effects of bran addition.     

Effect of Sources of Fibre on Performance of Growing Snail

The proximate and physicochemical properties of cassava leaf and peel meals were evaluated with a view to possible replacement of wheat offal which is the conventional source of fibre in animal feed, with these meals. The effect of feeds produced with cassava leaf and peel meals on the performance of growing snails was also investigated. Feeds (F1, F2 and F3) were formulated to contain 240, 235 and 230 g/kg cassava root meal each and 85, 85 and 90 g/kg cassava peel meal, wheat offal meal and cassava leaf meal respectively. The formulated feeds contain approximately 18.0% crude protein, 7.5% ash, 3% fat, 6.0% crude fibre 8%, calcium, 0.7% phosphorus, and energy level of 2400 kcal ME / kg. A total of 54 growing snails (Archachatina marginata) were used to investigate the nutritive potential of the formulated feeds on performance of growing snails for 15 weeks. Concentrations of the crude protein, crude fat, crude fibre, ash and calcium in cassava leaf meal were higher than those of wheat offal and cassava peel meal, with the exception of nitrogen free extract which was highest (70.01%) in cassava peel meal. Feed intake was 576 g 569 g and 581 g for snails fed with cassava leaf meal, cassava peel meal and wheat offal respectively but the corresponding weight gain ranged between 123.35 and 134.81 % being highest for F1. The feed conversion ratio shows that F1 > F3 > F2 indicating better conversion of feed to edible meat in F1. The results show that cassava leaves and peels have a strong potential to substitute the traditional wheat offal and can therefore be adapted as commercial feed ingredients.     

The bubble size distribution and its evolution in non-yeasted wheat flour doughs investigated by synchrotron X-ray microtomography

Determination of the bubble size distribution at the end of mixing and controlling its changes are the basis for improving bread quality before it is fully manufactured. X-rays from a synchrotron source (Biomedical Imaging and Therapy beamline, Canadian Light Source) were used to rapidly characterize the bubble size distribution and its evolution in non-yeasted dough subsamples as a function of time for 3 h following mixing. A complete X-ray microtomography scan was completed within 120 s. The higher number density of bubbles in dough compared to results previously reported in the literature was attributed to the better contrast and higher resolution (smaller pixel size, 8.75 μm) of the reconstructed X-ray images generated from synchrotron X-rays. The bubble size distribution was very well characterized with a lognormal distribution function. This distribution had a median bubble radius of 22.1 ± 0.7 μm at 36 min after the end of mixing which increased to 27.3 ± 0.7 μm over 162 min, a trend indicative of transport of gas in the dough due to disproportionation. This is the first time disproportionation in non-yeasted wheat flour doughs has been monitored directly under bulk conditions relevant to dough in bakery conditions. These results show that the diffusion-driven dynamics of bubbles in non-yeasted bread doughs can be followed by X-rays from a synchrotron source via feature extraction using image analysis software.     

Bread Making Potential of Composite Flour of Wheat-Acha (Digitaria exilis staph) Enriched with Cowpea (Vigna unguiculata L. walp) Flour

Bread-making potentials of composite flours containing 90% wheat and 10% acha enriched with 0-15% cowpea flour were investigated. Proximate composition and functional properties of the blends were studied using AOAC standard methods. Bread loaves were prepared from the blends using the straight dough method and evaluated for loaf height, loaf volume, loaf weight and sensory characteristics. Crude protein, crude fat, crude fibre and ash contents increased significantly (p < 0.05) with increase in level of cowpea flour addition, but moisture content was not significantly (p > 0.05) different among the blends. Functional properties, with exception of bulk density and swelling capacity, were significantly (p < 0.05) different among the blends. Average loaf height and loaf volume decreased significantly (p < 0.05) with increased cowpea flour but loaf weight showed opposite trend with significant (p < 0.05) differences as cowpea flour increased. However, the addition of cowpea flour significantly (p < 0.05) decreased the loaf specific volume but all enriched samples were not significantly (p > 0.05) different. Bread samples from composited blends were rated lower than bread from all wheat bread. Bread loaves from enriched composite flour with up to 10% cowpea flour were acceptable to the panelists.     

Effects of freezing treatments on the fermentative activity and gluten network integrity of sweet dough

The effect of freezing treatments on sweet dough was studied. The dough was frozen at ?20 °C, ?30 °C and ?40 °C in air-blast freezer cabinet and by immersion in liquid nitrogen. The yeast viability, gassing power, dough volume and dough network integrity from fresh and thawed sweet doughs were assessed. The results showed that both parameters depend on the freezing rate, which controls ice crystals size and location. Dough volume loss after freezing was attributed to reduced yeast fermentative activity and gluten network alteration in frozen dough. Fermentative activity reduced significantly in frozen dough using liquid nitrogen, causing 70% decrease on yeast population. Gluten integrity seemed to be affected by slow freezing treatment, i.e. ?20 °C and ?30 °C. Gas loss was also evaluated as a decrease of 25% ± 2 in dough volume. A correlation was observed between the freezing rate and osmotic pressure effects which influence strongly the yeast viability.     

Effect of superfine green tea powder on the thermodynamic,rheological and fresh noodle making properties of wheat flour

Superfine green tea powder (SGTP) was used to substitute 0 g, 1 g, 2 g, and 3 g of 100 g wheat flour (defined as 0SGTP, 1SGTP, 2SGTP and 3SGTP respectively) to make fresh noodles. The effects of SGTP on the viscosity, thermodynamic and rheological properties of wheat flour were evaluated, as well as the sheet colour, cooking quality, texture properties and sensory characteristics of green tea noodles. The results revealed that the stability, elastic modulus (G′) and viscous modulus (G″) of wheat dough all increased with the increase of green tea powder proportion. No significant differences were found in gelatinisation properties of the green tea-flour systems. Furthermore, adding SGTP could significantly (P < 0.05) retard the retrogradation of the gelatinised wheat flour gel. L¹ value of fresh noodles decreased as SGTP content increased while |a¹| value firstly increased and then decreased at 3 g/100 g. The 2SGTP noodle samples showed the least cooking loss. Sensory evaluation indicated that the control and the 2SGTP fresh noodles scored significantly (P < 0.05) higher in terms of colour. No significant difference was detected for the mouthfeel and overall acceptability among all samples.     

Physical,Sensory and Microbiological Properties of Wheat-Fermented Unripe Plantain Flour

The physical, sensory and microbiological properties of wheat-fermented unripe plantain composite flour bread were studied. Mature unripe plantain was peeled, sliced, steam blanched, dried and milled into flour. The flour was made into a slurry (10 g of flour/3 ml of water) and allowed to ferment for 24 h. It was then dried, pounded and sieved through 0.25 mm sieve. The fermented unripe plantain flour was then blended with wheat flour in the ratios of (wheat:fermented unripe plantain) 100:0; 90:10; 80:20; 70:30; and 60:40. Bread was produced from the flour blends using the straight dough method. Loaf weight and volume decreased significantly (p < 0.05) with increasing levels of plantain flour inclusion. Sensory evaluation of the flour samples revealed significant differences in the ratings for crumb colour and texture between 100% wheat flour (100:0) and 60% wheat-40% fermented unripe plantain flour (60:40) bread but no significant difference was observed between all bread samples with respect to crust colour, taste, aroma and overall acceptability. The sensory scores showed that all the bread samples were acceptable. Microbiological analysis (total viable count) revealed that all the bread samples were free of microorganisms for up to four days after production.     

Prediction of the nanomechanical properties of apple tissue during its ripening process from its firmness,color and microstructural parameters

Nanomechanical properties of fruit determine macroscopic firmness. Young's modulus (YM) of apple tissue obtained by atomic force microscopy (AFM) at cellular level and its correlation with other macroscopic physical parameters are used to evaluate ripening when apples were stored at 25 °C during 40 days. The YM of the tissue decreased from 0.96 ± 0.42 MPa (first day) to 0.11 ± 0.06 MPa (last day). The best linear correlation of YM was obtained with firmness (F) which decreased from 21.15 ± 0.79 N to 12.74 ± 0.34 N. Also various physical parameters obtained as peel color difference (ΔE) from 57.80 ± 0.97 to 66.51 ± 0.71, environmental electron microscopy (ESEM) such as entropy: Ent (from 8.67 ± 0.12 to 9.60 ± 0.17) and fractal dimension: FD (from 2.67 ± 0.05 to 2.75 ± 0.03) changed as well. Significant correlations (P < 0.05) were found between YM, F, ΔE, Ent and FD using Pearson analysis. Predictive models to evaluate YM from F, ΔE, Ent, FD were obtained by multiple linear regression, R² > 0.95 was found.Industrial relevanceThe study of the nanomechanical properties of fruit cells by AFM may provide insight into internally fruit properties and how changes in these properties over time influence the quality of the fruit. The determination of cell/tissue mechanics could be used to follow changes in the nanomechanical properties that occur during the processing and storage of climacteric fruits such as apples. The study of the nanomechanical properties of plant cells as well as their correlation with other useful food properties such as firmness, peel color and image texture could lead to a better understanding of the ripening process. Mathematical models to predict cell mechanical properties at the nanometric level through food quality parameters could be an innovation in food engineering and be a novel tool in evaluating the quality of apples. Benefits of the methods herein could be extended to address current issues, such as extending the storage life of other climacteric fruits and predicting nanostructural modifications to the cells when they are physically modified or chemically treated.     

Physical,Chemical and Sensory Properties of Baked Products from Blends of Wheat and African Yam Bean (Sphenostylis stenocarpa) Water-Extractable Proteins

Blends of wheat flour (WF) and African yam bean water-extractable proteins (AYBWEP) were processed into bread and cookies in the following ratios: 100: 0; 95: 5; 90: 10; 85: 15; 80: 20. The proximate composition, physical, chemical properties and sensory properties of bread and cookies samples from the blends were determined. Breads and cookies produced from the resultant blends were significantly higher (p < 0.05) in protein (16.39% – 18.36%) than the control (11.80% – 12.58%). Carbohydrate content decreased from 60.74% with addition of AYBWEP to 52.81% following 20% substitution. The pH of bread samples prepared from whole wheat flour and blends of wheat flour and AYBWEP were significantly different (p < 0.05) while bulk density and specific volume were not significantly different (p > 0.05). The pH of bread samples and cookies decreased with increase in the proportion of the AYBWEP blend from 5% to 20%. The highest specific volume (3.70 ml/g) was observed in bread samples prepared from the control 100: 0 blends while the 80:20 blends had the lowest specific volume (3.10 ml/g). There was no significant difference (p > 0.05) in the bulk density and thickness of the cookies. The cookies prepared using 80: 20 blends had the higher diameter (22.53 cm) and spread factor (54.03 cm) compared to the control. Generally, acceptability of the bread and cookies decreased with higher ratios of AYBWEP inclusion. The sensory acceptability scores showed the best AYBWEP substitution level for making bread and cookies was 5% and 10% of the AYBWEP respectively. The results are discussed in the context of the growing importance of promoting the processing and utilization of lesser known local crops in baked products.enrichment.     

Use of dried pumpkins in wheat bread production

Pumpkins belong to the family of Cucurbitaceae. They are classified to Cucurbita pepo, Cucurbita moschata, Cucurbita maxima and Cucurbita mixta, according to the texture and shape of their stems. The nutritional value of pumpkin fruits is high, varies from one species or cultivar to another. Pumpkins are reach in vitamins C, B₁, B₆, K, and in mineral substances. There are no data found about vacuum microwave dried pumpkin application in wheat bread production. The main purpose of the research was to evaluate quality parameters of microwave vacuum dried pumpkins and to verify its application in wheat bread production. Following quality parameters of pumpkins and bread made with pumpkin additive were evaluated: moisture content (oven – drying method), vitamin C content (iodometric), carotenoid content (spectrophotometric), reducing sugars (LVS 252:2000), colour changes (ColorTec- PCM), total fat content (ISO 6492:1999), degree of bread liking (ISO 4121:2003), bread baking loss and dry off. Quality parameters of non dried pumpkins were: content of reducing sugars − 2.40 g⋅100 g^-1, vitamin C – 0.26 g⋅100 g^-1, carotenoids – 0.50 mg % (in dry matter). The technological parameters for pumpkins drying in vacuum microwave drier were used: pressure (70–50 mmHg), speed of tumbler – 6 rpm, one working cycle and three stages. During the pumpkins drying process a decrease in the following parameters was observed: moisture content – 10.5 times, vitamin C content – 2.0 times; increase of yellowness (b*) value – 1.5 times. The optimal dried pumpkin additive to the wheat dough was 10% of the total flour amount. The wheat bread sample with dried pumpkins additive is richer in carotenoids and reducing sugars comparing to control wheat bread sample. The results of sensory analyses using hedonic rating demonstrated that a higher degree of liking was attributed to the bread sample with dried pumpkins additive (7.3) comparing to control wheat bread sample (6.7).     

Deterioration of olive,corn and soybean oils due to air,light, heat and deep-frying

To follow the relative rate of oxidative deterioration of edible oils, refined olive, corn and soybean oils were analyzed periodically for their peroxide value (PV), p-anisidine value (p-AV) and iodine value (IV) following exposure to air and air–light for 30 days. Changes in the above values of the oils were also examined and after being used for deep frying of French fries at 180 °C for varying periods of time i.e. 30, 60 and 90 min PV and p-AV values increased in the order, deep frying > air–light exposure > air exposure, while the values with respect to the oils increased as soybean > corn > olive. Decreases in IV followed the same pattern, i.e. deep frying > air–light > air and soybean > corn > olive. %Free fatty acid increased with increase in time of deep-frying. Deep-frying of French fries in corn oil was also carried out in presence of caffeic, ferulic, vanillic acid and crude tea extract as antioxidants. All antioxidants effectively reduced the oxidation rate in the oil as detected by decreases in PVs and p-AVs and relatively low reduction rates in IVs for all the frying times. The order of antioxidative activity was caffeic acid > vanillic acid > ferulic acid > tea extract. Variation in %FFA of corn oil due to variation in nature of fried food was also analyzed. %FFA of the oil used for deep frying of chicken drum sticks were higher than the values of the oil used for deep-frying of French fries.     

Antioxidant properties and components of some commercially available varieties of rice bran in Pakistan

The antioxidant activity of five indigenous rice bran varieties, i.e. Rice bran-Super kernel (RB-kr), Rice bran-Super 2000 (RB-s2), Rice bran-Super Basmati (RB-bm), Rice bran-Super-386 (RB-86) and Rice bran-Super fine (RB-sf), collected from the same agricultural plots, was evaluated. The order of antioxidant activity was evaluated by measurement of total phenolic content, antioxidant activity in linoleic acid system, reducing power, metal chelating ability, scavenging capacity by DPPH radical and ABTS cation radical and conjugated dienes. Determination of major antioxidant components reported in rice bran, i.e. tocopherols, tocotrienols and γ-oryzanol, was made using reverse phase HPLC. However, for comparison of tocopherol content, quantification was also done by voltammetry. The overall order of antioxidant activity was RB-kr > RB-s2 > RB-bm > RB-86 > RB-sf. However, according to the chelating activity and conjugated dienes assays the antioxidant efficacy of RB-sf was higher than RB-bm and RB-86. Antioxidant power was correlated with growth period and irrigation water demand by a particular variety. A strong correlation of these two parameters with antioxidant activity was observed. RB-kr has the longest growth period and takes the least amount of water out of the series and exhibits highest antioxidant activity. Strongly reverse behavior was observed in case of RB-sf.     

Quality changes of pasteurised mango juice during storage. Part I: Selecting shelf-life markers by integration of a targeted and untargeted multivariate approach

For the first time, a multivariate approach combining targeted and untargeted data was used to obtain insight into quality changes in pasteurised mango juice (cv. ‘Totapuri’) as a function of storage (42 °C for 8 weeks). Mango juice samples were formulated with addition of different potential precursors for different quality-related chemical reactions: ascorbic acid, citric acid and sugars. Control (diluted mango puree with water), ascorbic acid-enriched (AA₂₅₀ and AA₅₀₀), citric acid-enriched (CA, CA + AA₂₅₀ and CA + AA₅₀₀) and sugar-enriched (S) samples were characterised for a range of targeted quality parameters as well as for a volatile fingerprint (untargeted). Selection of shelf-life markers or quality parameters significantly changing during shelf-life was performed over all formulations as well as per mango juice formulation. Our study showed that a common trend over all formulations was observed for colour values (VID > │0.90│), while specific shelf-life markers were selected for each formulation. In acidified mango juice samples (CA, CA + AA₂₅₀, CA + AA₅₀₀), more terpene oxides were selected compared to other formulations. In ascorbic acid-enriched samples (AA₂₅₀, AA₅₀₀, CA + AA₂₅₀, CA + AA₅₀₀), furfural and ascorbic acid were significantly changing during shelf-life. It seems that the reaction pathways for compounds being formed or degraded upon shelf-life are clearly affected by the acidity level.     

Effect of Honey as Partial Sugar Substitute on Pasting Properties,Consumer Preference and Shelf Stability of Cassava-Wheat Composite Bread

The effect of partial substitution of sugar with liquid honey on the pasting properties of cooked dough made from cassava-wheat composite (10:90) flour as well as the sensory preference and shelf stability of its bread was investigated. Sucrose (S) in the bread recipe formulation was substituted with honey (H) at levels 0, 10, 20, 30, 40 and 50%, respectively to give 6 treatments, namely 0H:100S, 10H:90S, 20H:80S, 30H:70S, 40H:60S and 50H:50S. Amylograph pasting properties of the dried crumbs were determined using standard analytical procedures. Fresh bread samples were subjected to sensory evaluation and fungal count during storage (6 days). Peak, final and setback viscosities of bread crumb decreased (32.29 to 25.33, 58.54 to 43.00 and 30.96 to 23.66 RVU), respectively as the level of honey inclusion increased. Honey substitution levels used did not significantly (p > 0.05) affect aroma and texture of the bread samples but composite bread with 20% level of honey substitution was most preferred in terms of colour while composite bread with 30% level of honey substitution was most acceptable in terms of taste and overall acceptability. Fungal count in stored honey-cassava-wheat bread varied significantly (p < 0.05) from 0.6 to 4.0 × 10², 1.0 to 6.9 × 10², 2.2 to 57.0 × 10², 32.0 to 135.7 × 10², 34.0 to 140.0 × 10² and 42.0 to 159.3 × 10²) cfu/ml from day 1 to day 6, respectively. From the study, it was concluded that substitution of sugar with honey in dough formulations significantly (p < 0.05) affects dough pasting properties, improves acceptability of the composite bread and reduces staling rate.     

Enrichment of Noodles with Soy Flour and Carrot Powder

Noodles were produced from four flour blends of whole wheat, wheat-cassava, wheat-cassava-soy flour and wheat-cassava-carrot flour blends respectively. The flours were analyzed for proximate analysis, functional properties and total carotenoid content. The cooking time of all samples was also determined. Results show that there were significant differences (p < 0.05) between values obtained for moisture content, protein and total carbohydrates (p < 0.05) while values for fat and ash contents of the samples were not significantly different (p > 0.05). The functional properties also showed significant differences (p < 0.05) between the pasting properties except for pasting temperature and the cooking time of the samples. The total carotenoid content of the dried carrot sample was found to be 28.34 mg/100 g dry weight basis, while the noodle sample containing 10% dried carrot sample (CSC4) had a total carotenoid content of 1.80 mg/100 g dry weight basis. The results suggest that noodles made from the different flour blends can compare favourably with conventional noodles made from wheat flour in quality and that carrot flour can be used for noodle enrichment.     

Effect of oven and forced convection continuous tumble (FCCT) roasting on the microstructure and dry milling properties of white maize

The effect of oven and forced convection continuous tumble (FCCT) roasting on the microstructure of whole maize kernels was characterised and quantified using X-ray micro-computed tomography (μCT). The three-dimensional (3-D) volumes, reconstructed from the two-dimensional (2-D) images, were segmented into regions of interests (ROIs), i.e. air, germ, floury and vitreous endosperm, and each region quantified. Oven roasting was associated with a larger increase in total kernel volume (10.8%) than FCCT roasting (3.4%) as well as a significant (P ≤ 0.05) decrease in whole kernel relative density (oven = 6.3%; FCCT = 1.9%). FCCT roasting had almost no effect on material density, in contrast to a significant (P ≤ 0.05) decrease of 5.0% during oven roasting. Subsequent validation of the dry milling properties, i.e. percentage hominy chop, milling yield and hectolitre mass (HLM), indicated no significantly (P > 0.05) detrimental effect by either of the roasting methods.Industrial relevanceRoasting of maize can improve sensory, shelf life, nutritional and antioxidant properties with subsequent use in ready-to-eat foods and breakfast cereals. Roasting will inevitably affect the structure of maize, which in turn will affect the quality of the end product. This prompted the demand for non-destructive techniques that directly measure microstructural properties of food in order to link structure with quality. X-ray μCT in combination with image analysis uniquely illustrated the microstructural changes occurring during conventional oven and innovative FCCT roasting respectively. Furthermore, dry milling properties are important indicators of quality characteristics for the dry milling industry. The method described in this article can be applied to any food material to investigate structural properties.     

Effect of Addition of Ficus exasperata and Spoudias mombin Leaves on Functional and Sensory Properties of Cassava Roots in “Lafun” Production

Peeled and unpeeled cassava tubers (TMS 30572) were soaked with the leaves of Ficus exasperata (Ipin) and Spondias mombin (Iyeye) and the effects were determined on functional and sensory properties. The cassava samples were soaked in water to ferment for 72 h, pressed, dried, milled and sieved to obtain lafun flour. The lafun flour was reconstituted with hot water to produce a stiff dough and subjected to sensory evaluation using a 9-point Hedonic scale. Bulk density, water holding capacity, swelling index and dispersibility index varied from 0.53 to 0.63 g/cm³, 14.13 to 14.85 g/ml, 0.50 to 1.00 g/ml and 8.00 to 10.00 ml respectively. Lafun obtained from cassava steeped with F. exasperata leaves was significantly different (p < 0.05) from others; the maltose equivalent of lafun increased and this invariably reduced water absorption during dough preparation. Amylograph data showed that pasting time, temperature, peak viscosity, final viscosity and set-back value were between 4.00 to 5.15 min; 77.65 to 79.25°C; 331.33 to 371.17 RVU (Rapid Visco-Analyzer Unit); 225.50 to 279.00 RVU and 29.25 to 57.58 RVU respectively. Stiff dough of lafun samples obtained from unpeeled cassava steeped with F. exasperata had the highest mean scores for mouth feel, texture and overall acceptability, although all the samples were statistically similar (p > 0.05). The work revealed that F. exasperata increased the maltose equivalent and invariably reduced the level of water absorption in dough preparation. S. mombin on the other hand had no significant effect. Extract is more effective in stabilizing RPKO (hydrolytically and oxidatively) than MALE.