Comparison of structure and kinetic mechanism of phosphorylase forms isolated from water yam (Dioscorea alata) and white yam (Dioscorea rotundata) tubers

This study was conducted to evaluate the quality characteristics of Dioscorea rotundata and Dioscorea alata as alternative to potato in French fries production and effect of frying time on the quality index and acceptability of resultant yam chips. The yam chips were pretreated by blanching for 10minutes at 90o C, and soaking in 5% citric and sodium metabisulphite acid solution for a period of 30minutes. The treated blanched yam chips were deep fried at 170o C for 21 minutes, but the chips were withdrawn at intervals of 3minutes to determine the moisture content, textural properties and sensory attributes of the chips. The proximate composition of the fried chips was evaluated using established procedures of the Association of Official Analytical Chemists (AOAC). The textural properties such as Peak force and deformation at break of the deep fried chips were determined using a Universal Instron testing machine.The fried yam chips were subjected to sensory analyses (colour, crispiness, mouthfeel, taste, overall acceptability) using a 9- point Hedonic scale. Data obtained were subjected to Analysis of Variance ANOVA and means separated by Duncan Multiple Range test. The result of the proximate analysis on the two varieties of raw yam tubers showed that wateryam (D.alata ) had a significant (p>0.05) higher moisture content (69.49%) and protein values (7.60%) than white yam (D. rotundata) having 64.84% and 4.55% respectively).D alata had a significant (p>0.05) high fibre content of 2.34 % compared to D rotundata which had 1.42%. On the other hand, D. rotundata, has greater amount of carbohydrate (26.70%) than D. alata with (20.18%). A significant (p< 0.05) lower moisture content existed for the fried chips samples from 3 minutes to 18 minutes for both white yam (54.32-32.76%) and water yam (61.32- 31.03%).Frying time had a significant lowering effect on the moisture content of fried chips. White yam (D. rotundata) showed significantly (p>0.05) high force at peak than wateryam (D. alata), with values of 26.30N, and 7.30N respectively. Results showed that frying time had significant (p>0 05) effects on the peak force and deformation at peak of the fried yam chips for the two varieties. The pre-treatments given to the yam chips produced from the two yam varieties, gave some desirable sensory characteristics. The sensory scores showed that fried white yam chips had a significant (p>0.05) highest score (7.14) compared to wateryam fried chips (6.39) at 21st minute frying time even in terms of colour, taste, mouthfeel and overall acceptability. The use of yam as a substitute for potato in French fries production would make fries to be more affordable and promote its utilization in French fries production.

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IMPACT OF THE ADAPTED YAM MINISETT TECHNIQUE ON WARE YAM (DIOSCOREA ROTUNDATA) PRODUCTION UNDER FARMER-MANAGED CONDITIONS IN NIGERIA

Experimental Agriculture ◽

10.1017/s0014479716000120 ◽

2016 ◽

Vol 53 (1) ◽

pp. 131-143 ◽

Cited By ~ 4

Author(s):

STEPHEN MORSE ◽

NORA MCNAMARA

Keyword(s):

West Africa ◽

Dioscorea Rotundata ◽

Pests And Diseases ◽

Planting Material ◽

Published Evidence ◽

White Yam ◽

Funded Project ◽

Work Done ◽

Farmer Income ◽

Water Yam

SUMMARYWhite yam (Dioscorea rotundata) is a major root crop grown throughout West Africa and a major limitation on its production is the availability of good quality (i.e. free of pests and diseases) planting material, notably seed yams. One of the methods developed to address this limitation is the Adapted Yam Minisett Technique (AYMT) and since 2012 the AYMT has been promoted in both Nigeria and Ghana via a Bill and Melinda Gates funded project entitled Yam Improvement for Income and Food Security in West Africa (YIIFSWA). While previously published studies have focussed on the agronomy of the sett-to-seed yam process, there has been no work done on the seed-to-ware yam stage which is critical in terms of farmer income and livelihood. This paper provides the first published evidence obtained under entirely farmer-managed conditions in Africa that shows seed yams produced via the AYMT can generate agronomic benefits in the water yam stage, including better germination, tuber numbers and weights.

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Rapid assessment of resistance of tissue-cultured water yam (Dioscorea alata) and white guinea yam (Dioscorea rotundata) to anthracnose (Colletotrichum gloeosporioidesPenz.)

Archives of Phytopathology and Plant Protection ◽

10.1080/03235408.2012.749701 ◽

2013 ◽

Vol 46 (6) ◽

pp. 663-669 ◽

Cited By ~ 2

Author(s):

Akinola Rasheed Popoola ◽

Bosola Okuyinka Adedibu ◽

Sikiru Adebare Ganiyu

Keyword(s):

Rapid Assessment ◽

Dioscorea Alata ◽

Dioscorea Rotundata ◽

Guinea Yam ◽

Water Yam

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Iron, nickel, copper, zinc and cadmium content of two cultivars of white yam (Dioscorea rotundata) and their source soils

Journal of the Science of Food and Agriculture ◽

10.1002/jsfa.2740570314 ◽

1991 ◽

Vol 57 (3) ◽

pp. 431-435 ◽

Cited By ~ 4

Author(s):

Josiah J Bonire ◽

Neelam N S Jalil ◽

Joseph A Lori

Keyword(s):

Cadmium Content ◽

Dioscorea Rotundata ◽

Nickel Copper ◽

White Yam ◽

Iron Nickel ◽

Copper Zinc

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Potential for clean yam minisett production by resource-poor farmers in the middle-belt of Nigeria

The Journal of Agricultural Science ◽

10.1017/s0021859609008740 ◽

2009 ◽

Vol 147 (5) ◽

pp. 589-600 ◽

Cited By ~ 10

Author(s):

S. MORSE ◽

N. McNAMARA ◽

M. ACHOLO

Keyword(s):

Cropping System ◽

Economic Viability ◽

Treatment Results ◽

Care Needs ◽

Gross Margin ◽

Dioscorea Rotundata ◽

Planting Material ◽

White Yam ◽

Household Labour ◽

River Niger

SUMMARYYam minisett technique (YMT) has been promoted throughout West Africa since the 1980s as a sustainable means of producing clean yam planting material, but adoption of the technique is often reported as being patchy at best. While there has been much research on the factors that influence adoption of the technique, there have been no attempts to assess its economic viability under ‘farmer-managed’ as distinct from ‘on station’ conditions. The present paper describes the results of farmer-managed trials employing the YMT (white yam: Dioscorea rotundata) at two villages in Igalaland, Kogi State, Nigeria. One of the villages (Edeke) is on the banks of the River Niger and represents a specialist yam environment, whereas the other village (Ekwuloko) is inland, where farmers employ a more general cropping system. Four farmers were selected in each of the two villages and asked to plant a trial comprising two varieties of yam, their popular local variety as well as another variety grown in other parts of Igalaland, and to treat yam setts (80–100 g) with either woodash or insecticide/nematicide+fungicide mix (chemical treatment). Results suggest that while chemical sett treatment increased yield and hence gross margin compared with woodash, if household labour is costed then YMT is not economically viable. However, the specialist yam growers of Edeke were far more positive about the use of YMT as they tended to keep the yam seed tubers for planting rather than sell them. Thus, great care needs to be taken with planning adoption surveys on the assumption that all farmers should adopt a technology.

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