Effect of roasting on the chemical composition, functional characterisation and antioxidant activities of three varieties of marble vine (Dioclea reflexa): An underutilised plant.

Marble vine (Dioclea reflexa) seeds were roasted using the conditions in runs generated from Response Surface Methodology with temperature ranging from 110 to 200 °C and time (10-40 min). Proximate composition, antioxidant activities (DPPH, ABTS, FRAP, metal chelation OH and Lipid peroxidation) and Fourier Transform Infrared Spectroscopy (FTIR) were carried out on unroasted and roasted flours. Roasting increased the crude fibre content (2.74-5.08 %) of black variety compared to others. However, a slight denaturation of protein was observed when compared to unroasted samples. A significant increase in all the antioxidant activities compared to the control was also observed compared to unroasted flours. The FTIR showed functional groups such as ketones, aldehydes and carbonyl group upon roasting. Roasting temperature at (110 °C) had more effect than roasting time (10, 25 and 40 min). Hence, roasting at 110 °C could enable the release of food nutrients and improve the functionality of marble vine seed flour.

Effect of Fermentation on Nutritional Quality, Growth and Hematological Parameters of Rats Fed Sorghum-Soybean-Orange flesh Sweet Potato Complementary Diet.

The protein quality of complementary foods developed from fermented and unfermented sorghum, soybeans, and orange-fleshed sweet potato (OFSP) flour blends was evaluated using rat model. The test diet was as follows: UF2: unfermented sorghum (56%), soybean (17%), and OFSP (27%); UF3: unfermented sorghum (59%), soybean (31%), and OFSP (10%); F2: fermented sorghum (56%), soybean (17%), and OFSP (27%); and F3: fermented sorghum (59%), soybean (31%), and OFSP (10%), while cerelac served as positive control, corn starch (basal diet), and ogi (negative control). Forty-nine Wistar albino rats were grouped and fed with diets for 28 days. The growth, hematological, serum parameters of animals, protein quality, and proximate composition of developed diet were determined. Fermentation significantly improved the protein content and nutritional indices of experimental animals. Moisture content ranged from 2.5% to 9.24%, protein (7.09%-25.29%), ash (1.09%-3.71%), fat (10.28%-15.24%), and fiber (0.85%-3.17%). The biological values (BV) ranged from 75.11% to 78.44%. The weight gained in rat fed the formulated diet ranged from 46.0 g to 77.3 g and was highest in F3. The packed cell volume (PCV), hemoglobin concentration (HBC), red blood cell (RBC), and lymphocytes were highest in F3. Urea nitrogen and creatinine of the rats fed with formulated diets ranged from 3.58 to 15.32 mg/dl and 1.56 to 6.15 mg/dl, respectively. Sample F3 is a protein-rich complementary food that is comparable to ogi and suitable to manage malnutrition and support growth in children. However, clinical trials on the formulated diet are needed to further substantiate its nutritional potentials.

Cognitive impairment by non-insulin-dependent diabetes mellitus was attenuated by dietary supplements of marble vine (Dioclea reflexa) and plantain (Musa paradisiaca) dough meals in albino rats.

This study investigates the protective effect of formulated marble vine/plantain dough meals on cognitive impairment in diabetic rats. Wistar rats were divided into eight groups (n = 6) and fed with HFD for 14 days and a single dose of streptozotocin intraperitoneally on the 14th day (except control rats). Diabetic rats were treated with formulated diets and metformin. The ameliorative effect of the formulated doughs on cerebral damage in diabetic rats with respect to weight gain/loss, glucose and insulin levels, oxidative damage, neurological dysfunction, and histological alterations were assessed. The formulated diet had high protein and fiber content values ranged from 13.00 to 25.04 g/100 g and from 5.23 to 6.20 g/100 g, respectively compared to the control. Blood glucose level was observed, thereby mitigating the cerebral oxidative damage. The diet significantly ameliorated the neurological dysfunction as adjudged by increased dopamine concentration and lowered acetylcholinesterase activity; results were also supported by the outcomes from brain histopathological study. PRACTICAL APPLICATIONS: Underutilized leguminous seeds such as marble vine seeds are known for their nutraceutical potentials due to their numerous biochemical components. The study provides preliminary information on the potential of marble vine/plantain functional dough meals in the management of neurological complications resulting from type 2 diabetes mellitus in albino rats. Generally, the formulated doughs possess neuroprotective potentials in preventing neurological complications arising from diabetes. However, the effect of marble vine-plantain dough meal in managing the brain damage should be further investigated through the clinical trials before development for pharmaceutical applications.

Amino acid composition and antioxidant properties of the enzymatic hydrolysate of calabash nutmeg (Monodora myristica) and its membrane ultrafiltration peptide fractions.

The aim of this work was to determine amino acid composition and in vitro antioxidant activities of Monodora myristica protein hydrolysate and its membrane ultrafiltration peptide fractions. The Alcalase hydrolysate was fractionated using ultrafiltration membranes to produce peptide sizes of <1, 1-3, 3-5, and 5-10 kDa. The results showed that sequential fractionation resulted in higher glycine and glutamic acid and glutamine contents. Analysis of in vitro antioxidant properties showed that fractionation of the M. myristica hydrolysate led to significant (p < .05) improvements in 2,2-diphenyl-1-picrylhydrazyl radical scavenging, metal chelation activity, ferric reducing antioxidant power (FRAP), and hydroxyl (OH) radical scavenging activity. Linoleic acid oxidation was significantly (p < .05) attenuated by the peptide fractions. We conclude that peptide antioxidant activities were significantly (p < .05) improved by membrane fractionation, especially the 3-5 kDa fraction. PRACTICAL APPLICATIONS: The use of protein hydrolysate fractions with potential to prevent oxidation, which can reduce shelf life of foods and cause degenerate diseases due to cell damage is proposed for Monodora myristica. The demand for natural products and negative health issues associated with artificial food ingredients have led to increased consumer preference for natural sources of antioxidants. The protein hydrolysate and membrane fractions produced in this work showed high antioxidant ability that could qualify them to replace toxic synthetic antioxidants in foods. Peptide fractions had better metal chelation than the hydrolysates, which is important because chelation of metal ions can decrease the amount of free iron available to participate in the Fenton reaction and ultimately decrease the formation of toxic free radicals. Incorporation of the peptides into foods will enhance scavenging of toxic free radicals that may form during storage, thereby improving product freshness and shelf life in addition to preventing human degenerative diseases.

Effect of Roasting on the Phytochemical Properties of Three Varieties of Marble Vine (Dioclea reflexa) Using Response Surface Methodology.

This study assessed the optimum roasting conditions on the phytochemical properties of three varieties of Dioclea reflexa seeds using response surface methodology. Roasting conditions were varied using temperature (110°C~200°C) and time (10~40 min). Phytochemical components (phenolics, tannin, flavonoids, cardiac glycoside, and steroids) of the seeds were screened and estimated. The study showed that availability of phytochemical activities was heat-dependent. An increase in roasting temperature beyond 110°C for 10 min resulted in a decrease in total phenolic (TP) and flavonoid (TF) contents. However, prolonged durations of roasting favored increased amounts of TP and TF in dark and light varieties. Total sterol, tannin, and cardiac glycoside contents increased with increasing roasting temperature and time. The desirability of the models were 0.76, 0.74, and 0.72 for black, dark brown, and light brown, respectively. The coefficients of regression (R2), ranged from 0.66 to 0.98 signifying accuracy of the model. The following models (cubic, quadratic, and 2 factor interaction) were significant (P≤0.05). We found that roasting time influenced the phytochemical properties of D. reflexa to a greater extent than temperature. The optimum roasting temperature and time was found to beat 110°C, 35 min, 40 min, and 32 min in black, dark brown, and light brown varieties, respectively. Roasting conditions significantly affects the phytochemical contents of three varieties of D. reflexa seed flour (P<0.05). Therefore, D. reflexa holds the potential to be used in development of functional foods and in therapeutic applications to promote health.

Rheological, baking, and sensory properties of composite bread dough with breadfruit (Artocarpus communis Forst) and wheat flours.

The rheological (Pasting, farinograph, and alveograph) properties of wheat flour (WF) replaced with breadfruit four (05-40%) was analyzed. Baking and sensory qualities of the resulting bread were evaluated. Differences in baking properties of loaves produced under laboratory and industrial conditions were analyzed with t-test, whereas ANOVA was used for other analyses. Peak and final viscosities in the composite blends (CB) ranged from 109.20 to 114.06 RVU and 111.86 to 134.40 RVU, respectively. Dough stability decreased from 9.15 to 0.78 min, whereas farinograph water absorption increased 59.7-65.9%. Alveograph curve configuration ratio increased from 1.27 to 7.39, whereas specific volume (Spv) of the loaves decreased from 2.96 to 1.32 cm(3)/g. The Spv of WF loaves were not significantly different (P > 0.05) from that of the 5% CB, whereas production conditions had no significant effects on absorbed water (t = 0.532, df = 18 P = 0.3005), weight loss during baking (t = 0.865, df = 18, P = 0.199), and Spv (t = 0.828, df = 14.17, P = 0.211). The sensory qualities of the 5% blend were not significantly different from the WF.

Prebiotic effects of cassava fibre as an ingredient in cracker-like products.

Cassava fibre, a waste product formed in starch production, was incorporated into wheat to give composite flours at ratios of 80/20, 70/30, 60/40 and 50/50, respectively. A cracker-like biscuit was produced from the preferred ratios (60/40 and 50/50). The effects of these on diets as a prebiotic were evaluated in a rat assay. Determinations of the proximate composition and haematological parameters were made as well as microbiological analysis. The protein content of the cracker-like product based on the 50/50 and 60/40 (fibre/wheat flour) ratios were 15.0% and 10.0%, respectively. Crude fibre ranged from 14.1-17.1% while ash ranged from 3.0 and 5.0%. Low cholesterol levels of 28.75 mg dL(-1) and 18.75 mg dL(-1) were recorded for the 50/50 and 60/40 composite ratios, respectively. The result of liver function test showed that the rats that were fed the fibre-based cracker product had an average value of 44.00 IU L(-1) of aspartate amino transferase (AST), which is lower than the 67.75 IU L(-1) recorded for the control. There was a significant increase in the packed cell volume (PCV) of the rats fed a fibre-based diet, relative to those fed "Ogi" (fermented maize). Haemoglobin was significantly higher in the control sample than all others, while no significant difference was observed in the white blood cell (WBC) count, with average of 11.75 mm(3). Data obtained from the faecal analysis showed that the rats fed with the composite ratios and other diets had an increased Lactobacillus count. However, by increasing the number of days that the rats were fed the fibre-based diet, the E. coli count in the rat faeces reduced significantly. The data obtained shows that cassava fibre-based crackers have good nutraceutic effects, with reduction in the E. coli count found in the rat faeces and healthy performances in terms of weight gain.

Thermal stability of genistein and daidzein and its effect on their antioxidant activity.

Soy isoflavones, present in many processed soy foods, are known for their phytoestrogenic and antioxidant activities. The aim of this work was to study the kinetics of genistein and daidzein degradation at elevated temperatures and to follow changes in their antioxidant activity. Daidzein and genistein in model solutions (pH 7 and 9) were thermally treated at 120 degrees C or incubated at 70, 80, and 90 degrees C. Isoflavone degradation was observed at all temperatures, with apparent first-order kinetics at 70-90 degrees C, and E(a) = 8.4 and 11.6 kcal/mol at pH 9, respectively. Microcalorimetric stability tests showed a similar pattern of degradation, however, with higher E(a) (genistein, 73.7 kcal/mol; daidzein, 34.1 kcal/mol) that may be attributed to the anaerobic conditions. The antioxidant activity of incubated isoflavone solutions, followed by the ABTS test, decreased rapidly at pH 9 for genistein, whereas only moderate reduction was observed for daidzein (pH 7 and 9) or genistein at pH 7. This may indicate different degradation mechanisms for genistein and daidzein.

Comparison of the physicochemical properties and pasting characteristics of flour and starch from red and white sweet potato cultivars.

This research characterized flour and raw starches isolated from red and white sweet potato cultivars. Their composition, determined by proximate analysis, is typical of sweet potato cultivars. These cultivars have high amylose content (32-34%) and exhibit a Ca-type X-ray diffraction pattern. Similar gelatinization characteristics were detected for both starches with onset temperature of 67 degrees C and enthalpy of 10.5-11.0 J/g. Starches of both red and white cultivars had well-correlated (r (2) = 0.982) and high solubilization and swelling temperatures, starting at 80 degrees C. Pasting properties of the white cultivar exhibit lower tendency for retrogradation. Water and oil absorption capacities were low for both red and white flours. When parboiled, both cultivars showed improved water absorption capacity and decreased least gelation concentration. It is concluded that the white cultivar should be preferred when low retrogradation tendency is required.

A preliminary study on the use of tempe-based formula as a weaning diet in Nigeria.

Tempe, an Indonesian mold fermented food, was prepared from cowpeas and soybeans using the traditional oriental process with modifications where appropriate. Four complementary foods were developed from whole maize meal or dehydrated fermented maize (ogi) flour fortified with either cowpea tempe or soybean tempe. Wholesomeness and potentials of the vanilla-flavored foods as weaning diets were determined. The nutrient content of all the developed products were within the range prescribed by the FAO/WHO pattern for processed weaning foods. The products had loose bulk densities between 0.40-0.55 g/ml and packed bulk densities between 0.68-0.75 g/ml; reconstitution indexes were between 92.30-104.00 g/ml; viscosities were 34.2-65.0 CP at 70 degrees C and 45.0-76.9 CP at 30 degrees C. Total plate counts ranged from 3.2 x 10(3) - 4.3 x 10(4) cfu/g; coliforms staphylococcus, mold, and yeast were absent in some of the products. The results on sensory attributes showed that tempe-based weaning diets were comparable with Mameal, a commercial product. Maize and maize-fortified diets were slightly higher in packed bulk density. Fortification reduced the viscosity of the diets and the values reduced with increasing temperature. Tempe-based weaning foods reconstituted easily in hot water, while cooking destroyed most of the microorganisms present. Maize-based tempe fortified foods were relatively inexpensive and have potential as weaning foods.