Isolation and characterization of amylase from fermented cassava (Manihot esculenta Crantz) wastewater

The processing of cassava tubers for the production of nutrient enriched cassava flour, gari and farinha madioca, is usually accompanied with the production of stinking wastewater which usually constitute nuisance to both terrestrial and aquatic life. Thus, this study sought to assess the potential utilization of the wastewater as a source of industrial amylase. Wastewater from cassava mash fermented with pure strains of Saccharomyces cerevisae together with Lactobacillus delbruckii and Lactobacillus coryneformis for 3 days was assayed for amylase activity. The result of the study indicated that the fermentation wastewater had amylase activity, the unit activity and the specific activity of the amylase in the wastewater was 0.22 ìmole/min and 0.06 ìmole/min/mg, respectively. The amylase was purified using gel filtration (Sephadex- G150). The purified enzyme was maximally active at pH 6.0 and 60°C temperature. It had is maximum stability between pH 6 – 7 for 4 h, and 30°C for 50 min. NaCl, NH4Cl, FeCl3, KCl, NaNO3 activates the enzyme activity while CuSO4 and HgCl2 inhibit the activity of theamylase. It could therefore be concluded that these amylases from the fermented cassava waste water are active at wide temperature and pH ranges. This quality could be explored in the industrial sector(most especially food industry) as a source of industrial amylase that require a wide range of conditions (temperature and pH)

Cooking enhances the antioxidant properties of some tropical green leafy vegetables

Most leafy vegetables undergo cooking before consumption in tropical Africa. Therefore, this study sought to evaluate the effect of cooking on the vitamin C, total phenolics, total flavonoid and antioxidant properties [1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and 2,2- azinobis -3-ethylbenzo-thiazoline- 6-sulfonate radical (ABTS*) scavenging abilities, reducing property and Fe2+ chelating ability] of some tropical green leafy vegetables; Talinium triangulare, Ocimum gratissimum, Amaranthus hybridus, Telfairia occidentalis, Ipomea batata, Cnidoscolous aconitifolius, Baselia alba and Senecio biafrae leaves. The results of the study revealed that cooking causes a significant (P <0.05) decrease in the vitamin C [raw (321.4 - 842.0), cooked (198.2 - 638.4 mg/100 g)] content. Conversely, there was a significant (P < 0.05) increase in the total phenol [raw (146.9 - 693.8), cooked (272.9 - 1037.5 mg/100 g)] , total flavonoid [raw (8.2 - 53.0), cooked (12.9 - 57.4 mg/100 g)], DPPH radical scavenging ability [raw (15.7 - 61.8), cooked (52.8 - 92.7 %)], reducing property [raw (28.3 - 61.8), cooked (43.9 – 71.6 mg/100g AAE)], Fe2+ chelating ability [raw (17.4 – 75.4), cooked (22.8 - 89.2%)] and ABTS* scavenging ability [raw (17.4 - 87.3), cooked (57.5 - 113.2 mmol/100 gTEAC)]. In view of this, it could be concluded that cooking decreases the vitamin C contents in all the vegetables, while it increased the phenolic content and antioxidant activities.Key words: Vegetables, cooking, antioxidant, phenolic, vitamin C

Changes in the nutrient and anti-nutrient content of micro-fungi fermented cassava flour produced from low- and medium-cyanide variety of cassava tubers

Comparative studies were carried out on the ability of pure strain of Rhizopus oryzae and Saccharomyces cerevisae to alter the nutritional quality of cassava flour produced from low- and medium-cyanide variety of cassava tuber. Low- and medium-cyanide variety of cassava tubers were collected from International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. These tubers were washed, peeled, grated and aseptically inoculated with pure strains of R. oryzae and S. cerevisae innutrient solution, independently, before allowing them to ferment aerobically for 3 days. The fermented mash was subsequently dried and milled into cassava flour. Subsequently, the proximate, mineral andthe anti-nutrient composition of the cassava flour were determined. The results of the study revealed that the unfermented flour from low-cyanide cassava variety had higher protein, fibre, ash, fat, Ca, Naand K contents, while those produced from medium-cyanide variety, had higher anti-nutrient (tannin, cyanide and phytate), Zn, Mg and Fe contents. However, solid substrate fermentation of the cassavamash using R. oryzae and S. cerevisae, independently, caused a significant (P 0.05) in the ability of the fungi to decrease the antinutrient (except phytate) of the cassava flour. Furthermore, micro-fungi fermentation did not cause asignificant change (P > 0.05) in mineral content (except Mg and K) of the fermented cassava flour. Therefore, unfermented cassava flour produced from low-cyanide cassava tubers had high nutrientcomposition and low anti-nutrient content, and more susceptible to micro-fungi nutrient enrichment and detoxification than medium-cyanide variety. Furthermore, S. cerevisae was more efficient in thenutrient enrichment of the cassava flour than R. oryzae

Antioxidant Properties of Phenolic Extracts of African Mistletoes (Loranthus begwensis L.) from Kolanut and Breadfruit Trees

Mistletoe (Loranthus begwensis L.) has been used ethno-botanically for the management of several tropical diseases for centuries; and the medicinal properties have been associated with their host plant. Therefore, this study sought to investigate the antioxidant properties of mistletoe from two host plants (breadfruit and kolanut trees). The result of the study revealed that mistletoe from kolanut tree (0.69 mg/g) had higher total phenol content than that of breadfruit tree (0.49 mg/g). Furthermore, the extracts chelate Fe2+ and scavenge DPPH radicals in a dose-dependent (0 – 30 mg/ml) pattern. Nevertheless, the EC50 revealed mistletoes from kolanut as having higher DPPH scavenging (15.77mg/ml) than that of breadfruit (16.29mg/ml), while L.begwensis from Breadfruit tree had higher Fe2+ chelating ability (1.97mg/ml) than that of Kolanut tree (2.23mg/ml). Likewise, mistletoe from kolanut (27.5mg/AAE g) had higher ferric reducing ability (FRAP) than that of breadfruit (22.0mg/AAE g). Although both mistletoe extracts showed promise as good antioxidant sources, the total phenol content and the antioxidant capacity pattern of the extracts suggest host dependency. Keywords: antioxidant, breadfruit tree, kolanut tree, Loranthus begwensis L

Behavioral and Biochemical Indices of Neurotoxicity in Jimson weed Administered Rats

This study examined the effect of alkaloid extracts from leaf and fruit of Jimson weed (Datura stramonium L; a toxic food contaminant of global reputation) on cognitive function, antioxidant status and activities of critical enzymes of monoaminergic and cholinergic systems of neurotransmission in rats. Alkaloid extracts were prepared by solvent extraction method. The gas chromatograph coupled with mass spectroscopic (GC-MS) characterization of the extracts was also carried out. Thereafter, rats were administered 100 and 200 mg/kg body weight (p.o) of extracts for thirty days. Prior to termination of the experiment, the rats were subjected to spontaneous alternation and hole-board behavioral tests. Thereafter, rats were sacrificed and activities of acetylcholinesterase (AChE), monoamine oxidase (MAO) and antioxidant enzymes (superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase), as well as malondialdehyde (MDA) and total thiol (TSH) contents of their brain homogenates were determined. The results showed that rats administered the extracts exhibited reduced memory index and also exhibited increased level of anxiety-like behavior. Furthermore, rats administered the extracts exhibited significantly reduced levels of brain AChE, MAO, SOD, catalase and GST activities, reduced amount of brain TSH and elevated brain MDA content compared to control. Results from the GC-MS characterization revealed the presence of hyoscyamine (atropine), scopolamine, amphetamine, cathine, phenlyephirine and Tropine trifluoroacetate among others in the extracts. Therefore, the alterations in cholinergic, monoaminergic and antioxidant systems in brain of rats administered fruit and leaf alkaloid extracts of Jimson weed could be one of the major biochemical mechanisms underlying their ability to induce impairment of cognitive functions which could be significantly linked to their constituent alkaloids

Comparative effects of local Coagulants on the Nutritive Value, In vitro Multienzyme Protein Digestibility and sensory properties of Wara.

Wara, a Nigerian soft cheese, was produced from cow milk using different crude coagulants obtained (1) the juice of Calotropis procera, (2) an aqueous solution of calcium chloride, (3) an aqueous solution of alum (4) steep waste water from pap production. The objective of this study was to evaluate the effect of these coagulants on the yield, proximate analysis, mineral composition, energy content, in vitro multienzyme protein digestibility and sensory evaluation of Wara. The result revealed no significant difference (p≤0.05) in the yield of the cheese (31.5=32.5%) from the different coagulants. The protein (25.56%), Mn (0.23), Zn (1.9) of Calotropis procera coagulated cheese was significantly higher (p≤0.05) fat (21.9%), Fe (1.7), Mg (54.3), K (56.5), Ca (43.6), Na (45.2), energy (8.1 cal g-1) and in vitro multienzyme protein digestibility (80.3-92.6%) than the cheese produced by other coagulants. Calcium chloride coagulated cheese had the lowest content of protein (17.85%), Fe (0.993), Zn (0.785) and in vitro multienzyme protein digestibility (80.7-83.6%). Alum coagulated cheese had a high content of protein (23.64%), Fe (1.583), Ca (36.9) and Na (31.4). The results obtained from sensory evaluation showed that Calotropis procera coagulated cheese gave the best coagulum. The locally used coagulant in Nigeria for cheese production, steep waste water, appears to be promising because of its high content of minerals, though the sensory quality could be improved

EFFECTS OF DRYING METHODS ON THE ANTIOXIDANT PROPERTIES OF PHENOLIC-RICH EXTRACTS OF AFRICAN MISTLETOE (LORANTHUS BEGWENSIS L.) LEAVES FROM ALMOND AND KOLANUT HOST TREES.

Staff PublicationAfrican mistletoe (Loranthus begwensis L.) has been employed in sub-Sahara African folklore for the treatment of many degenerative diseases owing to its strong antioxidant properties. It has been reported that drying methods play an important role in herbs production. This study sought to investigate the most appropriate drying method by assessing the influence of these drying methods on the antioxidant properties of the leaves. Fresh leaves obtained from almond and kolanut host trees were subjected to oven drying, sun drying and air drying respectively after which the phenolic extraction was carried out. The influence of these drying methods on the total phenol and total flavonoid content as well as antioxidant properties (NO*, OH*, DPPH* scavenging and Fe2+ Chelating abilities) were assessed using standard methods. The total phenol ranged from 19.38 mg.GAE/100 g (Kolanut air-dried) to 39.47 mg.GAE/100 g (Almond oven-dried), while the flavonoid content ranged from 8.70 mg.QUE/100 g (Almond air-dried) to 21.81 mg.QUE/100 g (Almond oven-dried). In addition, all extracts scavenged DPPH [786.16 µg/ml (Almond oven-dried) to 1179.25 µg/ml (Kolanut air-dried)], NO [584.11 µg/ml (Almond oven-dried) to 1054.85 µg/ml (Kolanut air-dried)] and OH [404.86 µg/ml (Almond oven-dried) to 784.93 µg/ml (Kolanut air-dried)] radicals in dose-dependent manner as well as chelate Fe2+[377.64 µg/ml (Almond oven-dried) to 593.82 µg/ml (Kolanut air-dried)]. This study revealed that oven drying is the best method for mistletoe leaves obtained from almond host tree while sun drying is the best for mistletoe leaves obtained from Kolanut host tree as exemplified by their radical scavenging abilities and total phenolic compounds. Thus, diversity in drying methods leads to different loss of phenolic compounds and antioxidant property, suggesting that each plant family needs a special drying meth

Effect of Types of coagulant on the Nutritive value and in vitro multienzyme Protein Digestibility of Tofu

Tofu is popularly consumed in Nigeria because of the various nutritional and medicinal attribute associated with soybean products. In Nigeria, Tofu a coagulated product of soymilk is usually produced at household level using various types of coagulants such as Calcium chloride. Alum and steep water (effluent from pap produced from maize). This study therefore sought to assess the effect of the various type of locally used coagulants on the proximate, mineral, energy and antinutrient composition, and in vitro multienzyme protein digestibility of Tofu. The result of the study revealed that there was no significant difference (P>0.05) in the yield of the Tofu (17.5 – 18.3%), however alum coagulation gave the highest yield, while Calcium chloride gave the lowest yield. The protein (17.6%), fat (6.2%), Mn (0.3), Mg (34.2), energy (6.6 cal/g) and in vitro multienzyme protein digestibility (75.8 -77.6%) of steep water coagulated tofu was significantly higher (P< 0.05) Fe (1.6), Ca (23.5), K (33.9) and Na (21.1) than the tofu produced by other coagulants. The tofu produced by Calcium chloride had the highest Zn (0.6) content but the lowest energy content (5.3 cal/g) and in vitro multienzyme protein digestibility (61.6 – 63.5 %). It could therefore be concluded that of all the locally used coagulants in Nigeria for Tofu production steep water (effluent from pap produced from maize) which is considered to be waste appeared to be the most promising, although it has the least sensory acceptability, however further research will be carried out on how to improve its sensory quality