Cocoyam Corm Research Articles

Fungicidal Potentials of Leaf and Bark Extracts of Bryophyllum pinnatum on Cowpea (Vigna unguiculata L.) Seed Fungi

In Nigeria, Cowpea (Vigna unguiculata [L.] Walp) is an important grain legume which besides being a food crop serves as a major source of income for rural households. The action of pathogens on stored seeds causes huge post-harvest and economic losses to cowpea farmers in Nigeria. This research was aimed at isolating and identifying the spoilage pathogens of cowpea seed and testing the potentiality of ethanol extracts of Bryophyllum pinnatum on the isolates. Spoilt cowpea seed samples were purchased from different markets in Anambra State. They were transported to Alpha Research Laboratory, Awka in sterile polythene bags for microbial isolation. The spoilage organisms were isolated from the seeds through microbial culture. The media used for the isolation were Sabouraud Dextrose Agar and Potato Dextrose Agar. Pathogenic fungi were isolated from the spoilt cowpea seeds. The findings indicated that Aspergillus aculeatus, Fusarium solani, Penicillium citrinum, Rhizopus stolonifer, and Aspergillus flavus were present. The pathogenicity test also showed that the above organisms were responsible for cowpea spoilage. These isolates were tested for their in-vitro antifungal activity against the leaf and bark extracts of Bryophyllum Pinnatum. The antifungal activity ethanol extracts of Bryophyllum pinnatum on the isolated microorganisms were investigated using the disc method. Three different concentrations (25%, 50%, 100%) of extracts were used for the test. Fusarium solani showed the highest percentage of inhibition with antifungal medication while Penicillium citrinum showed the least percentage of inhibition with antifungal medication. The antifungal potential of Bryophyllum pinnatum extract on spoilage pathogens of stored cocoyam corms encourages more research on the active ingredient of the plant for easy use by farmers as alternative to commercial/ synthetic fungicides.

Physicochemical characteristics of tannia cocoyam (Xanthosoma sagittifolium) corm flour compared to flours and starches of other grains and tubers

Tannia cocoyam corm is a less popular pantropical carbohydrate source, whereas it has the potential to support food and nutrition security, especially in dry areas. Processing tannia cocoyam corm into flour can increase its use in various food products. This study aimed to determine the yield, nutrition, color, tap bulk density, water absorption capacity (WAC), oil absorption capacity (OAC), swelling capacity, and emulsion activity and stability of tannia cocoyam corm flour compared to sago starch, cassava flour and starch, mung bean starch, corn starch, wheat flour, rice and glutinous rice flours, and potato flour. The significant characteristics of tannia cocoyam corm flour were rather low in calories (dry basis), relatively high in WAC and swelling capacity, low in OAC, and showed emulsion activity and stability. Based on these data, it is suitable for use in mixed and processed food products that require juicy, elastic, and volume expansion characteristics; recommended for food products that are lower in calories and oil content; and can also help to maintain viscosity and form emulsions.

Bacteria and Fungi associated with the deterioration of Cocoyam Colocasia esculenta (Taro)

Aim: To isolate and identify the bacteria and fungi associated with the deterioration of Cocoyam with their respective percentage occurrences. Method: Cocoyam Colocasia esculenta (Taro) corms were obtained from a local barn in Umuahia, Abia State Nigeria and transported aseptically to the laboratory for further microbiological analysis. Sterile knife and forceps were used to obtain spoilt tissues from the cocoyam corms. A portion of the spoilt part of the cocoyam was cut out using the sterile knife and was inoculated into Nutrient agar and MacConkey agar plate for growth of bacteria. Another piece of the cocoyam was placed on potato dextrose agar for growth of fungi. Results: Bacterial isolates such as to Escherichia coli, Klebsiella pneumonia, Staphylococcus epidermidis, Staphylococcus aureus, Serratia marcescen and Bacillus subtilis were isolated from the samples. While fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer and Rhodotorula spp were equally isolated. Staphylococcus aureus had highest number of microbial isolate with total number of 8 (19.0%), follow by Klebsiella pneumonia with microbial isolate of 7 (16.7%), Escherichia coli and Aspergillus niger had 6 microbial isolate with frequency of (14.3%) each respectively, while Serratia marcescens, Rhodotorula spp while Aspergillus flavus had the least microbial isolate of 1 (2.4%). The presence of these organisms are responsible for the deterioration of cocoyam. Conclusion: Microbiological changes takes place during the storage of Cocoyam Colocasia esculenta (Taro). Therefore, there is need for better processing, handling techniques, good hygiene practices, safety and storage of the finished product. Findings obtained may be useful in the handling and storage of Cocoyam flour.

Bacillus cereus, Staphylococcus aureus, Aeromonas hydrophila, Pseudomonas aeruginosa and Proteus mirabilis associated with post-harvest storage of cocoyam (Colocasia esculentus L) corms rot: Occurrence and in vitro response to leaf extracts of Vernonia amygdalina

Cocoyam is a root crop that is produced in regions of the tropical or sub-tropical developing countries. In certain countries like Ghana, cocoyam production is surplus but post-harvest losses are high due to mechanical damage of corms during harvest which predisposes the corms to microbial attack in storage. Antibacterial activities of the test plant were determined using agar diffusion method. Five bacteria strains were isolated from rotten cocoyam corm viz: Bacillus cereus, Staphylococcus aureus, Aeromonas hydrophila, Pseudomonas aeruginosa and Proteus mirabilis. Cold aqueous extract of 20% of the test plant mostly inhibited Staphylococcus aureus (0.66) followed by Bacillus cereus (0.65). The least inhibited organisms being Pseudomonas aeruginosa (0.36) and Proteus mirabilis (0.38). Hot water extract (20%) of the test plant mostly inhibited Bacillus cereus (0.52) followed by Staphylococcus aureus (0.49). The results showed that higher concentrations of V. amygdalina extracts inhibited the growth of organisms more than lower concentrations. The use of plant based biocide against bacterial isolates proves efficacious as they are effective, affordable and are less harmful to man and the environment.

Effect of tannia cocoyam corm based diet supplemented with selenium on physical performance in broiler finisher chickens

Effect of tannia cocoyam corm based diet supplemented with selenium on physical performance in broiler finisher chickens

Isolation and Identification of Fungi Associated with the Spoilage of Cocoyam Corms

Cocoyam (Colocasia esculenta) is an important tropical root crop grown purposely for its starchy corms. This study was carried out to isolate and identify fungi associated with the spoilage of cocoyam corms. These organisms were isolated from spoilt corms by direct inoculation of the rotten tissues on Sabouraud Dextrose Agar. The fungal isolates were identified using cultural and morphological features such as colony appearance and also through microscopic characteristics. The isolated organisms include Rhizopus stolonifera, Rhizopus arrhizus, Fusarium oxysporum, and Aspergillus niger. Out of the 70 samples that were analyzed, 45 (64%) had Rhizopus stolonifera, 36 (51%) had Fusarium oxysporum, 52 (74%) had Rhizopus arrhizus while 61 (87%) had Aspergillus niger. A pathogenicity test was carried out on healthy corms using isolated microorganisms. The result showed that the organisms were responsible for the deterioration of the corms. These organisms may have infected these corms through contaminated working tools during harvest or improper storage by farmers. Corms are always infected by molds if not properly handled or stored. Hence, proper care should be taken while harvesting, handling, or storing these corms to avoid being infected by these pathogenic organisms since they can be detrimental to human health. It can also cause huge economic losses to farmers.

Yields and heavy metal uptake of cocoyam (Xanthosoma sagittifolium) and effects on soil properties of different tillage practices and application of burnt rice husk dust in Abakaliki, south-east Nigeria

ABSTRACT Indigenous crops play a critical role in the socioeconomic growth of developing nations where there have been calls for exploitation of these staple crops. This study investigated the yield and heavy metal uptake of cocoyam and changes in soil physical properties in relation to different tillage practices and the application of burnt rice husk dust (BRHD). The experiment was arranged as a split plot in a randomised complete block design (RCBD) with six treatments and three replications. The treatments were: mound tillage (no BRHD); ridge tillage (no BRHD); mound + 10 t ha−1 BRHD; mound + 20 t ha−1 BRHD; ridge + 10 t ha−1 BRHD and ridge + 20 t ha−1 BRHD. The results showed that soil bulk density (at 45 days after planting, DAP) was lower when the tillage practices were combined with the amendment of burnt rice husk dust, while total porosity (at 45 DAP) and aggregate stability were higher. The yields of cocoyam corms were also higher for tillage practices combined with amendment with burnt rice husk dust. The concentrations of heavy metals (Cu, Fe, Pb and Zn) in the cocoyam corms were higher for plants grown in soil amended with BRHD, but the levels were still below the levels considered harmful in food crops. Burnt rice husk dust could be recommended for use as a soil amendment in the study area to improve soil properties and increase the production of cocoyam, without increasing the concentration of heavy metals in the corms to harmful levels.

Effect of Hydrothermal Treatment on selected Properties of Cocoyam Corm (colocasia esculenta) Flour

The aim of this work is to evaluate the effect of hydrothermal treatment on the physicochemical properties of cocoyam flour. Harvested cocoyam (Colocasia esculenta) was sorted, peeled, washed, sliced, washed, blanched at temperature 60 ̊ C, 80 ̊ C and 100 ̊ C and soaked at different time of 12 hours, 24 hours and 48 hours after then oven dried. The dried samples were milled into flour labelled A, B, and C at three replicates (3×3×3=27) with unblanched and unsoaked sample D as control. The samples were packaged for analysis. Result showed that at temperature 60 ̊ C for soaking time 12 hours, 24 hours and 48 hours, the moisture content are 4.16 %, 3.62 % and 5.01 %, fat 5.22 %, 5.22 % and 4.72 %, crude fibre 0.98 %, 0.99 % and 0.53 %, protein 1.75 %, 1.47 % and 1.61 %. It is concluded that hydrothermal treatment of cocoyam (colocasia esculenta) can modify the physicochemical properties of flour produced. However, the minimum effect occurred at 60 ̊ C compared to 80 ̊ C and 100 ̊ C .thus, the quality of cocoyam flour can be improved using blanching temperature 60 ̊ C and 12 hours soaking time.

Dietary substitution of maize with processed cocoyam (Xanthosoma sagittifolium) as energy source for finisher broilers production

Energy feed source like maize is expensive contributing about 50-55% of the cost of poultry and pig diets. Thus, the study was carried out to determine the dietary substitution of maize with soaked cocoyam Xanthosoma sagittifolum as energy source for finisher broiler production. The soaked cocoyam tuber meal was used to replace yellow maize in the diets of finisher broilers. Xanthosoma cocoyam corms were harvested, cleaned of soil and chopped into bits of about 0.2 cm. The chopped tannia was soaked in water in a large vat for 24 hours to reduce the ant nutrients and later on separated from the water and dried with microwave oven. The dried cocoyam was milled and then used. The proximate chemical composition showed that soaked cocoyam tuber meal contained 8.05% moisture, 91.95% dry matter, 10.08% ash, 2.01% crude protein, 1.60% ether extract, 3.80% crude fibre, 74.46% NFE and 3158.92Kcal/kg DM metabolizable energy. In the finisher broiler trial, the control diet contained maize as the main energy source while diets 2, 3, 4 and 5 contained 15%, 20%, 25%, and 30% soaked cocoyam tuber meal finisher diet was fed to a group of 30 broiler chicks for 4 weeks using completely randomized design. Each treatment was further grouped into 3 replicated of 10 birds each. The broilers were kept in deep litter and given feed and water ad libitum. Parameters measured included: initial body weight, find body weight, body weight gain, feed intake, feed conversion ratio, cost of production and carcass characteristic. In the finisher feeding trial, the finisher broilers on the control diet, diet 5 (30% SCYM), and diet 3 (20% SCYM) recorded similar feed intake which were significantly different (P<0.05) from those on the other diets. In terms of body weight gain, the finisher broilers on 20% soaked cocoyam tuber meal diet recorded significantly (P<0.05) high body weight than those on other diets while the finisher broilers on 25% soaked cocoyam tuber meal recorded the poorest body weight gain. It appeared that, the finisher broilers could not tolerate high levels of soaked cocoyam tuber meal in their diets. Cost of production (cost of feed x feed conversion ratio) was lowest for diet 5 (30% SCYM) N375 versus N422.99 for control diet in the finisher trial. The internal organs expressed as percent of the live weight were not affected by the treatments. The finisher broilers on diet 3 recorded the highest dressing out percentage of 73.90.There were no significant difference (p<0.05) on percentage wings and back cut of the finisher broiler group in all the diets. The finisher broilers on diet 4 (25% SCYM) yielded the highest percent breast muscle of 32.4% followed by those on 15% SCYM (diet 2) and 20 SCYM (diet 3). The finisher broilers on the control diet yielded the highest percent thigh of 18.3% and the poorest were those on diet 2(15% SCYM). The results of the trial have shown that soaked cocoyam tuber meal can be used to substitute maize at 20% in the diets of finisher broilers without affecting the weight gain, feed intake and feed conversion ratios as indicated in this study.

Growth performance of starter broilers fed processed cocoyam (Xanthosoma sagittifolium) as energy source in place of maize

Considering the inherent attributes of cocoyam (Xanthosoma sagittifolium), its appropriate utilization for chicken diets may enhance performance of starter broilers. The study was therefore, carried out to determine the growth performance of starter broilers fed processed cocoyam tuber meal as energy source in place of maize. Xanthosoma cocoyam corms were harvested, cleaned of soil and chopped into bits of about 0.2 cm. The chopped tannia was soaked in water in a large vat for 24 hours to reduce the ant nutrients and later on separated from the water and dried with microwave oven. The dried cocoyam was milled and then used. The proximate chemical composition showed that soaked cocoyam tuber meal contained 8.05% moisture, 91.95% dry matter, 10.08% ash, 2.01% crude protein, 1.60% ether extract, 3.80% crude fibre, 74.46% NFE and 3158.92Kcal/kg DM metabolizable energy. In the starter broiler experiment, five experimental diets were formulated such that, diet 1 (control) contained yellow maize as the main energy source, while soaked CTM was used to replace maize at levels of 15%, 20%, 25% and 30% respectively in the control diet. Each starter diet was fed to a group of 30 broiler chicks for 4 weeks using completely randomized design. Each treatment was further grouped into 3 replicates of 10 birds each. The broiler chicks were kept in deep litter and given feed and water ad libitum. Parameters measured included initial body weight, final body weight, feed intake, feed conversion ratio and cost of production. In the starter feeding trial, the group on 30% soaked CTM (30% SCYM) compared favorably with the control group (P<0.05) and recorded the highest body weight gain. It appeared that, the starter broilers could tolerate high levels of soaked CTM in their diets. Cost of production (cost of feed x feed conversion ratio) was lowest for diet 5 (30% SCYM) N248.15 as against N281.86 for control diet in the starter feeding trial. CTM meal can be used to replace maize at 30% in the diets of starter broilers without affecting weight gain, feed intake and feed conversion ratio as indicated in the study.

Performance, carcass and blood indices of broiler chickens fed graded levels of sundried raw wild cocoyam (Colocasia esculenta (L.) Schott) corms as partial substitutes for maize

The suitability of graded levels of sun-dried raw wild cocoyam (Colocasia esculenta (L.) Schott) corms as partial replacement for maize in the diet of finishing broiler chickens was carried out in a feeding trial that lasted for four weeks. One hundred and twenty (120) four weeks old broilers were used. . The birds were assigned into four dietary treatments of three replicates each. The experiment was carried out using the completely randomized design. Each diet represented a treatment. Diet 1 as the control treatment was devoid of the test ingredient. The remaining three (3) diets were formulated on 10, 20 and 30% substitution levels of raw wild cocoyam corms for maize on a weight for weight basis. The diets and clean drinking water were provided ad libitum throughout the period of the study. Data were collected on performance, carcass, haematology, serum metabolites, and economy of production. Results revealed that the weight gain, feed conversion ratio, cost per kilogramme feed and carcass characteristics were significantly (P < 0.05) affected by the dietary treatments. Among the serum metabolites and haematological parameters monitored, only cholesterol was significantly (P < 0.05) affected by the graded levels of the test ingredients in the diets. It was concluded that maize can be replaced with 20% of raw wild cocoyam corms without deleterious effects on performance, carcass, serum biochemistry and haematology of broiler chickens.

Growth performance and carcass characteristics of finisher broiler chickens fed diet containing cooked cocoyam tubermeal

This study was carried out to evaluate the growth performance and carcass characteristics of finisher broiler chickens fed diet containing cooked cocoyam tubermeal as energy source in place of maize. The proximate composition of cooked cocoyam tubermeal showed that it contained 13.11% moisture, 2.60% ash, 3.90% crude protein, 9.45% crude fiber, 1.85% ether extract and 70.13% NFE. In the finisher feeding trial, the cooked cocoyam tubermeal was used to replace maize at levels of 25%, 50%, 75% and 100% respectively in the control diet. Each finisher diet was fed to a group of 30 finisher broiler chicken for 4 weeks using completely randomized design. Each treatment was divided into 3 replicates of 10 broiler chicks each. The birds were kept on deep litter and were given feed and water ad-libitum. Parameters measured include ifinal body weight, body weight gain feed intake, feed conversion ratio, carcass characteristics and economics of production. In the finisher feeding trial, the feed intake of the finisher broilers on diets 2, 3 and 4 were similar and compared favourably with those on the control diet. The finisher group on 100% CCYM (diet 5) recorded the lowest feed intake possibly because of the dustiness of the feed. The body weight gain of the finisher broilers on diet 2 (25%) cooked cocoyam tubermeal compared favourably with the control group and was significantly (P<0.05) higher than those on other diets. It appeared that the finisher broilers could not tolerate high levels of cooked cocoyam meal due to dustiness of the feed and its anti-nutritional factors. The cost of production per kg finisher broilers was cheapest for diet 5(100% CCYM) (N356.72) and the costliest was for diet 3(50% CCYM) (N588.28). The internal organs expressed as percent of the live weight were not affected by the treatments. In terms of carcass characteristics, the finisher broilers on diet 2(25% CCYM) recorded the highest breast muscle which was significantly different (P<0.05) from other groups. There were no significant different (P>0.05) on percent back cut, drumstick, head, shank, thigh, neck and wings of the finisher broilers on all the treatments. There were no significant differences (P > 0.05) in percent dressed weight of the finisher broilers on cooked cocoyam based diets. The results of the trial have shown that cooking cocoyam corms (Xanthosoma sagittifolium) for 30 minutes was effective for reducing the cyanide oxalate, tannin, phytic acid and saponin content and that cooking did not affect the proximate composition of tannia. Cooked cocoyam tubermeal could be used to replace maize up to 25% in the diet of finisher broiler chicken without affecting body weight gain, feed intake and feed conversion ratio as indicated in this study.

Egg quality characteristics of layer hens fed varying levels of yellow cocoyam corm meal (<i>Xanthosoma sagittifolium</i>) as energy source

This experiment was carried out to determine the effect of sun-dried cocoyam corm meal (SDCCM) on the performance and egg quality characteristics of layer hens. Poultry industry in Nigeria is faced with numerous challenges among which is the scarcity and high cost of poultry feed fueled by high cost of energy and protein feed feedstuffs such as maize, sorghum, oat, millet etc. Cocoyam corm meal has been discovered as cheaper energy source than grains such as maize or wheat and was used to formulate layer hens’ diets as energy source at 0.0%, 10.0%, 15.0% and 20% levels of inclusion respectively. These were used to feed a batch of one hundred and twenty (120) Isa brown pullets starting at their point of lay for a fifty-six (56) days feeding trial. The birds were grouped into four treatments of 30 hens per group and replicated three times with 10 birds per group in a Completely Randomized Design (CRD). Proximate composition of the experimental material was evaluated while the laying hens performance and egg quality characteristics were determined. The results obtained showed no treatment effect (P>0.05) for all the performance characteristics except for feed cost and hen – day egg production which were significantly reduced (P<0.05) in the test diets at 20% dietary levels. Similarly, all the external egg quality characteristics measured in this study were similar (P>0.05) in all the treatments means except for egg shell weight which was reduced significantly (P<0.05) in T4 (20% DCCM). However, all the treatment groups retained similar (P<0.05) egg shell thickness and were within the range of 0.30 – 0.36mm reported for egg shell thickness. However, for internal egg quality characteristics, results obtained in all the treatment means were similar (P>0.05). Albumen height and haugh unit values were, 7.19, 7.36, 7.13, and 7.23cm and 83.75, 83.79, 82.53 and 83.80 respectively. It was therefore concluded that dried cocoyam corm meal is an ideal feed ingredient in layer hen’s diets at 20% inclusion level.
 Keywords: Performance, egg quality characteristics, layer hens and sun-dried cocoyam corm meal.

Performance of laying hens fed graded levels of dried yellow cocoyam corm meal (<I>Xanthosoma sagittifolium</I>) as partial replacement for maize

Yellow cocoyam (Xanthosoma sagittifolium), a tropical root crop is presently underutilized as energy feedstuff in poultry diets. The objective of this experiment was to evaluate the effects of dried cocoyam corm meal as partial replacement for maize on egg laying and haematological parameters of layer hens. Fifty-six (56) days feeding trial was conducted using one hundred and twenty (120) Isa brown layer hens of twenty weeks (20 weeks) old. Sample of the cocoyam corm meal used for this study was analyzed in the laboratory to determine its proximate nutrient composition. Results showed moisture content 79%, ash 4%, fat 1.1%, fibre 5.5%, carbohydrate 24%, protein 8.05% and energy 3160.05kcal/kg DM. The cocoyam corm meal was used to formulate layer hens’ diets: T1, T2, T3, and T4 at 0%, 10%, 15% and 20% inclusion levels respectively. The experimental layer hens were divided into four treatment groups of thirty (30) hens each which was further replicated three times, ten (10) birds per replicate in a Completely Randomized Design (CRD). Each group of the experimental birds was subjected to one of the experimental diets for the period of 56 days and drinking water was also provided regularly. At the expiration of the experiment, three (3) birds were selected from each group for haematological parameters evaluation. Average daily feed and total feed intake showed no significant (P>0.05) difference though T4 was higher (P<0.05) among the treatments and T1 was the least (P<0.05). Total body weight gained was significantly (P<0.05) higher at T4. T2 was significantly (P<0.05) the lowest among other treatments. T1 had a significant (P<0.05) highest hen day egg production followed by T2 and T3 which were statistically the same (P>0.05) while T4 had the lowest (P<0.05) among the treatments. T2 had the heaviest (P<0.05) egg weight of 65.40g while T1 had the lowest (P<0.05) (61.76g) though still within the same category of large in USDA (2000) egg weight rating. Feed efficiency of feed/g egg weight was higher at T2 (1.27). T4 (1.38) had the lowest (P<0.05) feed conversion efficiency with no significance (P>0.05) difference among values obtained from other treatments. T1 had the highest pack cell volume (P<0.05). Red blood cell, count, haemoglobin and white blood cell count values which did not differ significantly (P>0.05) among the values of T2, followed by T3. Results obtained in the haematological parameters evaluated showed significant difference (P<0.05) recorded in some values; T3 had the highest haemoglobin (20.46 pg) followed by T4 (20.34 pg), T1 had the least (19.80 pg) but still within the recommended range for layer hens for optimal performance. It is concluded that dried cocoyam corm meal (Xanthosoma sagittifolium) is an ideal ingredient in layer hens diets up to 15% inclusion level for good performance.
 Key words: Egg production, growth, haematology, proximate composition.

Prospects for the utilisation of cocoyam corm meal in poultry feeding

Context The increasing demand for maize for human food and industrial uses has stimulated research interest into alternative low value crops as energy sources for poultry. Several high yielding species of aroids, commonly known as taro or cocoyam, are currently in less demand for food or industrial uses and readily available for poultry feeding. Aims To review the production, nutritional profile and antinutritional factor and current uses of cocoyam corm and the effect of processing on its utilisation in poultry feeding. Key findings The nutritional profile of cocoyam with protein content comparable or higher than maize, high starch content and starch digestibility make it a suitable energy ingredient for poultry. The major issues affecting the utilisation of cocoyam include the high moisture and low dry matter contents and the presence of antinutritional factors, mainly calcium oxalate. These constraints may preclude the utilisation of cocoyam corm in commercial diets but it could be used to reduce the cost of production on small-holder farms. Conclusion With adequate processing and proper diet formulation, cocoyam corm meal may be fed up to 280 g/kg diet but unprocessed meal may exert adverse effects on poultry performance even as low as 44 g/kg. Several animal factors including age, species and type of bird (meat or egg) affect the utilisation of cocoyam corm meal by poultry. Implications Reduction of cost of animal protein production and value addition to underutilised aroids. More research is needed into animal factors and feed processing that would allow optimum utilisation of the corm by poultry.

Characterization of cocoyam (Xanthosoma spp.) corm flour from the Nazareno cultivar

Abstract The present study assessed the physical, chemical, functional, and microbiological properties of cocoyam (Xanthosoma spp.) corm flour made from the Nazareno cultivar. The flour was initially submitted to a water-soaking process in order to reduce its high oxalate content. The soaked flour showed a high dietary fiber content (15.4% insoluble and 2.8% soluble fiber), and can be considered essentially an energy-rich food given its high starch content (60.5%), of which 85.04% was analyzed as amylopectin; it also showed a high potassium content (19.09 mg/g). The anti-nutritional component analysis showed low levels of oxalate (5.55 mg/g), saponins (0.10%) and tannins (0.07%), while phytates were not detected. The flour had a high water and oil absorption capacity (9 - 11 g/g at 90 and 100 °C; 1.2 g/g) and it gelatinized at between 81.81 - 89.58 °C. It was also microbiologically stable after storage for 9 months at room temperature. Development of a multipurpose flour from cocoyam corm could provide a value-added option for the local food industry.

Comparative Assessment of Yield Performance of Neglected Cocoyam (Colocasia esculeta (L.) Schott) Parts as Planting Materials in the South Western Nigeria

Hitherto, there is scarcity of information on the usefulness of neglected small corms and cormels of cocoyam in the South West Nigeria. A 9 (nine) months trial was conducted to compare the growth and yield performance of different types of cocoyam planting materials with treatment consisting of T1; sprouted small cocoyam cormels, T2, trimmed out lower parts of harvested cocoyam corm and T3; moderate sized corm of 50-100g (control) arranged in a Randomised Complete Block Design (RCBD) with three replicates. Data on the number of leaves and plant height was taking at 4 week interval for 24 weeks while data on number and weight of harvested cormels was taking at 9 months after planting (MAP). The data collected were subjected to a univariate General Linear Model (GLM) two ways Analysis of Variance (ANOVA) using IBM SPSS software statistical package 21. Significance mean differences were separated using Duncan Multiple Range Test (DMRT) at 0.05 level of significance. The result showed that the highest mean number of leaves and plant height was obtained from treatment T1 (10.22) and T2 (92.83) respectively at 24 weeks after planting (WAP). While both treatment T1 and T3 collectively had the highest number of consumable cormels (54.0) in which treatment T3 weighed the highest (3.202 kg). There was no significant difference (P>0.05) in both the number of leaves produced and plant height among the different cocoyam planting materials utilised at 24 (WAP). Similarly, there was no significant difference (P>0.05) in the number and weight of cormels produced by the different treatments at 9 months after planting (MAP). The study therefore concluded that both sprouted small cocoyam cormels, trimmed out corms during planting compared favourably with moderate sized corm of weight 50-100g commonly used as planting material in term of yield potential and therefore recommended to be schedule for demonstration to cocoyam farmers in the study area for adoption.

Sorption Characteristics of Cocoyam (Colocasia Esculenta) at Different Temperatures

The exploitation of cocoyam (Colocasia esculenta) for food is limited to direct consumption of primary products which often result in huge post-harvest losses. This study reports the development and storage of flour from cocoyam with the intent of establishing suitable storage conditions for its storage. Fresh cocoyam corms obtained from the Federal University of Technology (FUTA) Research Farm, were peeled, washed, sliced, oven-dried and then milled into the powder. Insights into the is essential to maintain Good keeping quality of food materials is a function of the relationship between their air relative humidity (expressed as water activity (aw)) and equilibrium moisture content. The gravimetric method was used to determine the adsorption isotherms of cocoyam flour. In the range of temperature (20 - 40 oC) and aw (0.10 - 0.80) typical of the tropical environment, different concentrations of concentrated acid (H2SO4) solutions were used to vary the condition of the research area. The experimental data were compared with six widely recommended models for food sorption isotherms (GAB, BET, Oswin, modified Oswin, Hasley & Smith). The plot of moisture sorption isotherms also resulted in a sigmoidal shape which is influenced by temperature variation. Generally, the Modified Oswin model was found most suitable to describe the sorption isotherm of cocoyam flour.

Effects of slaughter house wastes on soil properties and cocoyam corm yield in Abakaliki, Nigeria

A research was carried out in research and teaching farm of, Ebonyi State University, Abakaliki to determine effects of different rates of slaughter house wastes on soil properties and cocoyam corm yield. Four rates of slaughter house wastes namely 0 (control), 3, 6 and 9 t ha‒1 were used as amendment. Soil and cocoyam were analysed using analysis of variance and differences between treatment means detected using Fisher's least significant difference (FLSD) at 5% probability level. Results from the study showed that slaughter house wastes application significant (P < 0.05) improved soil properties and cocoyam corm yield compared to control. Also, the higher the application of slaughter house wastes in the plots, the higher the improvements in soil properties though not all the improvements were significant (p < 0.05). Slaughter house wastes significantly increased cocoyam corm yield compared to control.

Effects of slaughter house wastes on soil properties and cocoyam corm yield in Abakaliki, Nigeria

Effects of slaughter house wastes on soil properties and cocoyam corm yield in Abakaliki, Nigeria