Proximate and Mineral Composition Variability in Ethiopian Yam (<i>Dioscorea</i> spp)

Abstract

Abstract:Fourty two yam (Dioscorea species) sprouted tubers were collected from six different major growing regions of Ethiopia and planted at Hawasa Agricultural Research Center. The Dioscorea species considered in this study were D. bulbifera, D. abyssinica, D. cayenensis, D. rotundata, D. praehensilis, and D. alata. Five Proximate compositions (moisture, ash, crude fat, crude protein and crude fibre) and four minerals content (calcium, phosphorous, zinc and iron) were determined from 100g yam tubers at Ethiopian Health and Nutrition Research Insititute (EHNRI). High variability was observed among and within yam species due to their proximate composition and mineral content. The range of protein, moisture, iron, fat, fibre, ash, zinc, calcium and phosphorous content for all the fresh yam tubers observed in the study were between (3.13% -6.29%),(4.67% -13.57%), (17.21mg/100g. -90.85mg/100g), (0.26% -7.86%), (1.82% -6.36%), (1.68% -4.41%), (0.38 mg/100g -8.33 mg/100g), (6.3 mg/100g -121.26 mg/100g) and (8.72 mg/100g. -56.12 mg/100g) respectively. The correlation study indicated that presence of significance association between nutritional content to some yam agronomic traits.

Effect of predrying treatment and drying temperature on proximate composition, mineral contents, and thermophysical properties of anchote (Coccinia abyssinica (Lam.) Cogn.) flour

“…Both blanching and boiling might enhance the loss of water‐soluble components and increase the percentage of macromolecules rich in dietary fiber. The TF of the raw and pretreated anchote flours (6.34 – 10.92 g/100 g) was higher than values reported for other tuberous crops (potato, sweet potato, cassava, cocoyam, and yam) by several previous researchers (Aathira & Siddhuraju, 2017; Baah et al., 2009; Bekele & Bekele, 2018; Egbuonu & Nzewi, 2016; Harijono et al., 2013; Lewu et al., 2009; Nascimento & Canteri, 2018; Onodu, Culas, & Nwose, 2018; Ukom et al., 2018). Therefore, anchote flour can be used to enhance dietary fiber by incorporating into other foods or by aiding in the formulation of diets for people with diabetes and other health‐conscious individuals.…”

“…The variations may be due to variety, growing ecology, tuber maturity, and treatment methods used (Abera & Haile, 2015; Ayalew, 2016; Shebabaw, 2013). It was observed that the anchote flour contains reasonably higher Ca compared to other common tuberous flours such as sweet potato (50.28–110.53 mg/100 g), potato (9 mg/100 g), and yam (31.02–118.8 mg/100 g) (Bekele & Bekele, 2018; Koua, Zoué1, T L R M…”

“…Crude fiber content was determined by the Weende scheme as adopted by Bekele and Bekele (2018). About one gram of the dried sample was boiled for 40 min in 50 ml dilute sulfuric acid (2.5%) and filtered.…”

“…The ether extract (taken as crude fat content) in the sample was determined by the soxhlet (Diethyl ether) method, as described by Bekele and Bekele (2018). The dried anchote flour sample extracted with diethyl ether for 1 hr.…”

The Dioscorea Genus (Yam)—An Appraisal of Nutritional and Therapeutic Potentials

“…Over the years, several scientific studies have evaluated and reported the nutritional qualities of different Dioscorea species, as shown in Table 1 and Table 2 . The nutritional abundance of yam varies depending on the species and variety, as well as the environmental conditions and agricultural practices engaged during planting [ 35 , 36 ]. The analytical method used for estimation also plays a significant role in nutritional levels recorded in yam.…”