Open Access. Powered by Scholars. Published by Universities.®
Social and Behavioral Sciences Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Economics (25)
- Food Chemistry and Quality Control (11)
- Food Process Engineering (10)
- Turfgrass Management (7)
- Fermentation (6)
-
- Post-harvest Technology and Management (6)
- Chocolate (5)
- Mixed-species (5)
- Agriculture (4)
- Forest management (4)
- Maize (4)
- Private native forests (4)
- Viscoelastic properties (4)
- Viscosity (4)
- Child nutrition (3)
- Cool Plants - Antarctic Research (3)
- Cowpea (3)
- Electrometallurgy (3)
- Fauna (3)
- Flora (3)
- Food security (3)
- Genetic variation (3)
- Hydrometallurgy (3)
- Pyrometallurgy (3)
- Rainforest (3)
- School Feeding Programmes and Child Nutrition (3)
- School feeding (3)
- <em>Lolium perenne</em> L. (2)
- <em>Poa annua</em> L. (2)
- <em>Poa pratensis</em> L. (2)
- Publication Year
- Publication
-
- Professor Emmanuel Ohene Afoakwa (27)
- William Edwards (25)
- Professor Jerome K Vanclay (22)
- David J. Wehner (7)
- Rebecca W. Dolan (7)
-
- Fathi Habashi (5)
- Sharon Robinson (5)
- Rafael Jiménez-Flores (2)
- Brett C. Ratcliffe (1)
- Catherine Sands (1)
- Dan Nettleton (1)
- Douglas L Karlen (1)
- Dr Anastasia Tsaliki, PhD (1)
- Dr Lyndon O Brooks (1)
- John Hadidian, PhD (1)
- Kayla Harris (1)
- Neil E. Harl (1)
- Olivier Cadot (1)
- Pr. Mamoudou H. DICKO, PhD (1)
- Terence Hays (1)
Articles 91 - 112 of 112
Full-Text Articles in Social and Behavioral Sciences
Heat Tolerance Screening Of Field-Grown Cultivars Of Kentucky Bluegrass And Perennial Ryegrass, D. D. Minner, P. H. Dernoeden, David J. Wehner, M. S. Mcintosh
Heat Tolerance Screening Of Field-Grown Cultivars Of Kentucky Bluegrass And Perennial Ryegrass, D. D. Minner, P. H. Dernoeden, David J. Wehner, M. S. Mcintosh
David J. Wehner
The quality of cool-season turfgrasses frequently declines during periods of high temperature stress. Simple tests are needed to rapidly identify heat tolerant germplasm for incorporation into breeding programs. Facilitative screening tests have been devised, however, in the few studies that have been performed only immature and greenhouse or growth chamber-grown plants have been evaluated. To be of practical value, results of screening tests, employing plants grown under artificial conditions, should correlate closely with results of tests involving field grown plants. The objective of this research was to evaluate the heat tolerance of several cultivars of Kentucky bluegrass (Poa pratensis L.) …
Urease Activity In A Kentucky Bluegrass Turf, W. A. Torello, David J. Wehner
Urease Activity In A Kentucky Bluegrass Turf, W. A. Torello, David J. Wehner
David J. Wehner
The components of a turfgrass ecosystem, including plants, an intervening layer of thatch and the underlying soil, influence the fate of topically applied urea fertilizer. The loss of urea N by ammonia volatilization may be governed by the rate of urea hydrolysis. The main objective of this study was to determine the extent of urease activity associated with turfgrass plant tissue, thatch, and the underlying soil. This information may help elucidate the mechanism of ammonia loss following urea application. Because a turfgrass stand frequently possesses an extensive thatch layer that may serve as the primary plant growth medium, additional objectives …
Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke
Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke
David J. Wehner
Use of cool-season turfgrasses in transitional environments is limited, in part, by their heat tolerance. Development of a rapid heat tolerance screening technique would be of value in determining the potential of turf•grasses for use in warmer areas. The heat tolerance of 22 Kentucky bluegrass (Poa pratensis L.) cultivars, Poa annua L., and four perennial ryegrass cultivars (Lolium perenne L.) was evaluated by exposing plants for 30 min to temperatures ranging from 41 to 49 C in single degree intervals. Ten-week-old plants, which had been grown under a low level of N fertilization and watered infrequently to maximize heat tolerance …
Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke
Heat Tolerance Of Kentucky Bluegrasses, Perennial Ryegrasses, And Annual Bluegrass, David J. Wehner, T. L. Watschke
David J. Wehner
Use of cool-season turfgrasses in transitional environments is limited, in part, by their heat tolerance. Development of a rapid heat tolerance screening technique would be of value in determining the potential of turf•grasses for use in warmer areas. The heat tolerance of 22 Kentucky bluegrass (Poa pratensis L.) cultivars, Poa annua L., and four perennial ryegrass cultivars (Lolium perenne L.) was evaluated by exposing plants for 30 min to temperatures ranging from 41 to 49 C in single degree intervals. Ten-week-old plants, which had been grown under a low level of N fertilization and watered infrequently to maximize heat tolerance …
Effect Of P, K, And Lime On Growth, Composition, And P Absorption By Merion Kentucky Bluegrass, T. L. Watschke, D. V. Waddington, David J. Wehner, C. L. Forth
Effect Of P, K, And Lime On Growth, Composition, And P Absorption By Merion Kentucky Bluegrass, T. L. Watschke, D. V. Waddington, David J. Wehner, C. L. Forth
David J. Wehner
Information is needed concerning the effects of different soil fertility levels on the activity of turfgrass roots in that part of the soil profile sampled for routine soil tests. In Pennsylvania, a sampling depth of 5 to 7.5 cm is suggested for established turf. A study was conducted on 'Merion' Kentucky bluegrass (Poa pratensis L.) to determine relationships among lime, phosphorus, and potassium applications; soil test results; foliar growth and elemental analysis; and root activity as determined by 32P uptake from three soil depths. In the field, soil pH values were 5.8 and 7.0, P ranged from 13 to 137 …
Response Surface Methodology For Studying The Effect Of Processing Conditions On Some Nutritional And Textural Properties Of Bambara Groundnuts (Voandzei Subterranea) During Canning, Emmanuel Ohene Afoakwa, Agnes Simpson Budu, Alan Bullock Merson
Response Surface Methodology For Studying The Effect Of Processing Conditions On Some Nutritional And Textural Properties Of Bambara Groundnuts (Voandzei Subterranea) During Canning, Emmanuel Ohene Afoakwa, Agnes Simpson Budu, Alan Bullock Merson
Professor Emmanuel Ohene Afoakwa
The response surface methodology and central composite rotatable design for K=3 was used to study the combined effect of blanching, soaking and sodium hexametaphosphate salt concentration on moisture, ash, leached solids, phytates, tannins and hardness of bambara groundnut during canning. Regression models were developed to predict the effects of the processing parameters on the studied indices. Significant interactions were observed between all the factors with high regression coefficients (64.4-82.6%). Blanching and soaking of the seeds prior to canning led to increases in moisture content and leached solids, while significant decreases were observed for phytates, tannins and hardness of the canned …
Response Surface Methodology For Optimizing The Pre-Processing Conditions During Canning Of A Newly Developed And Promising Cowpea (Vigna Unguiculata) Variety, Emmanuel Ohene Afoakwa, Samuel Yenyi, Esther Sakyi-Dawson
Response Surface Methodology For Optimizing The Pre-Processing Conditions During Canning Of A Newly Developed And Promising Cowpea (Vigna Unguiculata) Variety, Emmanuel Ohene Afoakwa, Samuel Yenyi, Esther Sakyi-Dawson
Professor Emmanuel Ohene Afoakwa
Cowpea (IT87D195Y) seeds were canned with the objective of investigating the optimal pre-processing conditions that would yield the best quality canned product from the newly developed cowpea variety. Pre-canning procedures such as blanching time, soaking time and sodium hexametaphosphate [(NaPO3)6] salt concentration were used as the independent variables for a Central Composite Rotatable Design (CCRD). The pre-processing parameters obtained from the CCRD were used for the canning of the cowpeas and the quality characteristics (moisture content, pH of the drained liquid, drained weight, splitting of the seeds, leached solids and seed hardness) of the canned products were studied using response …
How Costly Is It For Poor Farmers To Lift Themselves Out Of Subsistence, Laure C. Dutoit, Olivier Cadot, Marcelo Olarreaga
How Costly Is It For Poor Farmers To Lift Themselves Out Of Subsistence, Laure C. Dutoit, Olivier Cadot, Marcelo Olarreaga
Olivier Cadot
The main objective of this paper is to provide estimates of the cost of moving out of subsistence for Madagascar's farmers. The analysis is based on a simple asset-return model of occupational choice. Estimates suggest that the entry (sunk) cost associated with moving out of subsistence can be quite large---somewhere between 124 and 153 percent of a subsistence farmer's annual production. Our results make it possible to identify farm characteristics likely to generate large gains if moved out of subsistence, yielding useful information for the targeting of trade-adjustment assistance programs.
Application Of Response Surface Methodology For Studying The Product Characteristics Of Extruded Rice-Cowpea-Groundnut Blends, Emmanuel Asare, Samuel Sefa-Dedeh, Emmanuel Ohene Afoakwa
Application Of Response Surface Methodology For Studying The Product Characteristics Of Extruded Rice-Cowpea-Groundnut Blends, Emmanuel Asare, Samuel Sefa-Dedeh, Emmanuel Ohene Afoakwa
Professor Emmanuel Ohene Afoakwa
Response surface methodology (with central composite rotatable design for k=3 was used to investigate the product properties of extruded rice-cowpea-groundnut blends in a single screw extruder. The combined effect of cowpea (0-20%), groundnut (0-10%), and feed moisture (14-48%) levels were used for formulation of the products. The product moisture, expansion ratio, bulk density and total colour change were studied using standard analytical methods. Well-expanded rice-legume blend extrudates of less bulk density and lower moisture content were produced at low feed moisture. Increasing legume addition affected the various shades of colour in the product. Models developed for the indices gave R2 …
The Microflora Of Fermented Nixtamalized Corn, Samuel Sefa-Dedeh, Beatrice Cornelius, Wisdom Amoa-Awua, Esther Sakyi-Dawson, Emmanuel Ohene Afoakwa
The Microflora Of Fermented Nixtamalized Corn, Samuel Sefa-Dedeh, Beatrice Cornelius, Wisdom Amoa-Awua, Esther Sakyi-Dawson, Emmanuel Ohene Afoakwa
Professor Emmanuel Ohene Afoakwa
Nixtamalization is a traditional process that improves the nutritional quality of corn. To provide a means of utilizing the nutritional benefits of nixtamalized corn and improve product acceptability, lactic acid fermentation was applied. The objective of the study was to study the microbial profile and establish the important lactobacilli of fermenting nixtamalized corn dough. Two batches of cleaned whole corn were subjected to the process of nixtamalization, using two concentrations of lime (0.5 or 1.0%), milled, made into a dough (50% moisture) and fermented spontaneously for 72 h. A control sample was prepared without alkaline treatment. pH and titratable acidity …
Effects Of Cowpea Fortification, Dehydration Method And Storage Time On Some Quality Characteristics Of Maize-Based Traditional Weaning Foods., Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh, Esther Sakyi-Dawson
Effects Of Cowpea Fortification, Dehydration Method And Storage Time On Some Quality Characteristics Of Maize-Based Traditional Weaning Foods., Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh, Esther Sakyi-Dawson
Professor Emmanuel Ohene Afoakwa
Fortification of cereal-based traditional foods with legume protein can improve their nutritional value. It is, however, important to find out the extent to which the addition of cowpea affects the desirable quality characteristics of traditional weaning foods prepared from fermented maize and also to assess the effect of dehydration method and storage time on the chemical, physico-chemical and functional properties of the products. A 3 x 2 x 4 factorial experiment with cowpea level, drying method and storage time as the respective variables was done. The traditional weaning food was prepared by steeping maize in water for 24 hours, mixed …
Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko
Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko
Pr. Mamoudou H. DICKO, PhD
The latest estimates of the FAO demonstrate the problems of the fight against hunger. These problems are manifested by the ever-increasing number of chronically undernourished people worldwide. Their numbers during the 1999-2001 period were estimated at about 840 million of which 798 million live in developing countries. Sub-Saharan Africa alone represented 198 million of those. In this part of Africa the prevalence of undernourishment ranges from 5-34%, causing growth retardation and insufficient weight gain among one third of the children under five years of age and resulting in a mortality of 5-15% among these children. Malnutrition resulting from undernourishment is …
Effect Of Nixtamalization On The Chemical And Functional Properties Of Maize, Samuel Sefa-Dedeh, Beatrice Cornelius, Emmanuel Ohene Afoakwa
Effect Of Nixtamalization On The Chemical And Functional Properties Of Maize, Samuel Sefa-Dedeh, Beatrice Cornelius, Emmanuel Ohene Afoakwa
Professor Emmanuel Ohene Afoakwa
The high utilization and consumption levels of maize in developing countries calls for investigations into new methods of processing to help introduce variety as well as improve the functionality and nutrient quality of maize-based foods. This study was carried out to determine the effect of nixtamalization on the chemical and functional characteristics of maize. A 2X4 factorial experimental design with cooking time (0, 30 min) and lime concentration (0, 0.33, 0.5 and 1.0%) was performed. Chemical composition (moisture, protein and ash), pH, titratable acidity, water absorption, colour, cooked paste viscosity and texture were determined using standard methods. The cooking time …
Effect Of Fermentation On The Quality Characteristics Of Nixtamalized Corn, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh, Beatrice Cornelius
Effect Of Fermentation On The Quality Characteristics Of Nixtamalized Corn, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh, Beatrice Cornelius
Professor Emmanuel Ohene Afoakwa
Spontaneous lactic acid fermentation is an important process in cereal processing. It is applied to develop and enhance taste and flavour, modify texture and improve the microbial safety of foods. When applied to nixtamalized corn mixed with traditional steeped corn it is expected to further improve the functionality, improve nutritional quality and provide an alternative corn-based ingredient. The objective of this study was to investigate the chemical and functional properties of fermented blends of steeped and nixtamalized corn. A 3_5 factorial experimental design with fermentation time (0, 24, 48 h) and blends composition (0:100, 25:75, 50:50, 75:25, 100:0 steeped:nixtamalized corn) …
Viscoelastic Properties And Changes In Pasting Characteristics Of Trifoliate Yam (Dioscorea Dumetorum) Starch After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Viscoelastic Properties And Changes In Pasting Characteristics Of Trifoliate Yam (Dioscorea Dumetorum) Starch After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Professor Emmanuel Ohene Afoakwa
Studies were conducted on the viscoelastic properties, as well as the changes in pasting characteristics, of trifoliate yam, Dioscorea dumetorum, starch during post-harvest hardening of the tubers. A 3x4 factorial experiment with blanching treatment time (0, 15 and 30 s) and storage time (0, 12, 24 and 36 h) as the respective variables was performed. The samples were evaluated for pasting temperature, viscosity at 95 _C, viscosity at 95 _C-Hold, viscosity at 50 _C and viscosity at 50 _C-Hold, as well as their changes during storage of the tubers, to determine the starch behaviour of the D. dumetorum tubers during …
Textural And Microstructural Changes Associated With Post-Harvest Hardening Of Trifoliate Yam (Dioscorea Dumetorum) Pax Tubers, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Textural And Microstructural Changes Associated With Post-Harvest Hardening Of Trifoliate Yam (Dioscorea Dumetorum) Pax Tubers, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Professor Emmanuel Ohene Afoakwa
The textural and microstructural changes associated with the post-harvest hardening phenomenon of Dioscorea dumetorum tubers were studied to determine how texture relates to microstructure during the hardening process. A 2x2x4 factorial experiment with sample treatment,storage conditions and storage time as variables was performed. The tubers were harvested,matured and stored under prevailing tropical ambient conditions (28 _C) and cold room conditions (4 _C) for the study. All the samples were evaluated for their hardness (peak force) and adhesiveness (curve areas). Starch microscopy was done on the freshly harvested tubers,hardened tubers and tubers stored under low temperature conditions (4 _C) during the …
Changes In Cell Wall Constituents And Mechanical Properties During Post-Harvest Hardening Of Trifoliate Yam Dioscorea Dumetorum (Kunth) Pax Tubers, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Changes In Cell Wall Constituents And Mechanical Properties During Post-Harvest Hardening Of Trifoliate Yam Dioscorea Dumetorum (Kunth) Pax Tubers, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Professor Emmanuel Ohene Afoakwa
In an attempt to investigate the changes leading to the rapid post-harvest hardening of the white cultivars of Dioscorea dumetorum tubers, alterations in the plant cell wall constituents and mechanical properties of the tubers were monitored. A 4x2 factorial experiment with storage time (0, 24, 48 and 72 h) and storage conditions [cold room (4 _C, 85–100% RH) and tropical ambient (28 _C, 62–100% RH)] as variables were performed. Harvested tubers were stored for 24, 48 and 72 h under 4 and 28 _C. Changes in mechanical properties, acid and neutral detergent fibres, lignin, cellulose and hemicellulose contents were monitored. …
Changes In Rheological Properties And Amylase Activities Of Trifoliate Yam, Dioscorea Dumetorum, Starch After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Changes In Rheological Properties And Amylase Activities Of Trifoliate Yam, Dioscorea Dumetorum, Starch After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Professor Emmanuel Ohene Afoakwa
Changes in rheological properties and amylase activities occurring in trifoliate yam, Dioscorea dumetorum, starch after harvest were investigated. Trifoliate yam tubers were harvested and stored under tropical ambient (28 _C) and cold room conditions (4 _C) for 12, 24 and 36 h. The D. dumetorum starches were extracted from the tubers under study and samples were evaluated for changes in their rheological properties (paste characteristics) during storage and to study the action of amylases on D. dumetorum starch after harvesting. The post-harvest activities of a and b-amylases were also studied to evaluate their rate of action on D. dumetorum starch. …
Biochemical And Textural Changes In Trifoliate Yam Dioscorea Dumetorum Tubers After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Biochemical And Textural Changes In Trifoliate Yam Dioscorea Dumetorum Tubers After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Professor Emmanuel Ohene Afoakwa
Biochemical and textural changes were investigated in trifoliate yam Dioscorea dumetorum tubers, after harvest, in an attempt to study the chemical and physical changes associated with the raw and cooked tubers and how these relate to the hardening phenomenon of the tubers after harvest. A 2x2x3x4 factorial experiment, with cultivar, storage condition, treatment and storage time as their respective variables, was done. Samples were analysed for moisture, starch, reducing sugars, alcohol-soluble sugars, acid and neutral detergent fibre, cellulose, hemicellulose and lignin. The Warner–Bratzler test cell was used in a TA.XT2 Texture Analyser to measure the hardness of cooked tubers. The …
Η Πανίδα Και Η Χλωρίδα Στην Προϊστορική Κύπρο, Anastasia Tsaliki
Η Πανίδα Και Η Χλωρίδα Στην Προϊστορική Κύπρο, Anastasia Tsaliki
Dr Anastasia Tsaliki, PhD
No abstract provided.
Influence Of Fermentation And Cowpea Steaming On Some Quality Characteristics Of Maize-Cowpea Blends, Samuel Sefa-Dedeh, Yvonne Kluvitse, Emmanuel Ohene Afoakwa
Influence Of Fermentation And Cowpea Steaming On Some Quality Characteristics Of Maize-Cowpea Blends, Samuel Sefa-Dedeh, Yvonne Kluvitse, Emmanuel Ohene Afoakwa
Professor Emmanuel Ohene Afoakwa
Fermentation and cowpea steaming can be used to improve the protein quality and quantity of fermented maize dough. In the production of maize-cowpea blends, it is important that the quality characteristics are evaluated to determine their functionality in the products. A 5x4x2x2 factorial experiment with cowpea level, fermentation time, cowpea steaming time and fermentation method as the variable was performed. The cowpeas were dehulled, steamed, dried at 65EC for 24 hours and milled into flours. Maize was soaked in water (18 hours), drained and milled into flour. The maize-cowpea blends were made into a 50% moisture dough, fermented for the …
Chemical Composition And Quality Changes Occurring In Dioscorea Dumetorum Pax Tubers After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Chemical Composition And Quality Changes Occurring In Dioscorea Dumetorum Pax Tubers After Harvest, Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh
Professor Emmanuel Ohene Afoakwa
Studies were conducted on the chemical composition, as well as the biochemical and textural changes, occurring during storage of two cultivars of Dioscorea dumetorum yam tubers. The tubers were harvested and stored under tropical ambient (28_C) and cold room conditions (4_C) for 24, 48 and 72 h. The samples were evaluated for moisture, starch, sugars, fibres and textural properties. Chemical analysis showed no significant differences between the means obtained for moisture, ash, protein, fibre, fat, carbohydrate, calcium, phosphorus, iron, vitamin A and vitamin C contents of the cultivars (white and yellow) studied. During storage, moisture contents decreased by approximately 6–10% …