Browsing by Author "Mwakasege, Emmanuel"

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Fatty Acid Contents and Stability of Oyster Nut Oil (Telfairia pedata) Compared to Flaxseed and Sunflower Oil
(Hindawi, 2021-11-21) Mwakasege, Emmanuel; Treydte, Anna; Hoeglinger, Otmar; Kassim, Neema; Makule, Edna
The selection of healthy fats for consumption is important. Linoleic acid (LA) (omega-6) and alpha-linolenic acid (ALA) (omega-3) are essential polyunsaturated fatty acids required for the maintenance of good health; however, LA derivatives such as arachidonic acid (AA) are associated with the onset of inflammatory diseases, and both are prone to oxidation and deterioration. This study compared the fatty acid contents, peroxide value (PV), p-anisidine value (p-AV), and free fatty acids (FFA) of the oyster nut oil with refined sunflower, nonrefined sunflower, and flaxseed oil stored at 27°C for 40 days. Flaxseed oil had significantly high ALA content (59.8%) compared to 0.1-0.5% for oyster nut and sunflower oil brands. The LA content was high in sunflower brands (50.3-52.8%) compared to the oyster nut (48%) and flaxseed oil 14.7%. Oleic acid was lower in oyster nut oil (8.6%) and flaxseed oil 15.8% compared to sunflower brands (35.7-38.2%). As a consequence, oyster nut and flaxseed recorded higher PV of 4.35-2.88 mEq O2/kg and FFA 0.26-0.47% compared to sunflower brands. The p-AV recorded small values which were not significantly different in all samples. Although oyster nut is widely consumed by pregnant and lactating women across Africa, its keeping quality in nonrefined form is low compared to flaxseed and sunflower oil as shown in this study. Hence, the fatty acid contents in oyster nuts should be consumed in other alternative forms such as flour and roasted kernels rather than its oil when in nonrefined form. This study will enable the consumption balance of omega-6/omega-3 fatty acids and the keeping quality of oils which is key to health.
Variations in nutrient composition and oil stability of oyster nuts (telfairia pedata) across different agro- climatic conditions in Northern Tanzania
(NM-AIST, 2021-07) Mwakasege, Emmanuel
In sub-Saharan Africa, nutrient deficiency remains a challenge. The challenge is partly due to the underutilization of available nutrient sources and failure to optimize nutrients based on agroclimatic conditions. Oyster nuts (Telfairia pedata) are the under-utilized oilseeds with promising food and non-food applications. This study investigated oyster nut's nutrient composition and variations across different sites and elevation levels encompassing different agro-climatic conditions. Additionally, the stability of crude oyster nuts oil, flaxseed oil, and sunflower oil were compared. Fats were the most abundant contents of the nuts with 68%, followed by 25% protein, 5% carbohydrates, and 2% ash. Fatty acid contents were dominated by linoleic acid (47%), while magnesium was the most abundant mineral (150 mg/100 g). Protein and fat contents increased significantly with declining elevations, while sites did not show any significant effects. In contrast, linoleic acids and minerals such as magnesium (Mg) and phosphorus (P) of the nuts decreased significantly in low elevations. Other nutrients such as carbohydrates, potassium (K), palmitic acid, iron (Fe), and stearic acid in the nuts were not significantly affected by neither site nor elevations. Finally, oyster nut oil produced high peroxide value (PV) and free fatty acids (FFA) compared to flaxseed and sunflower oil at room temperature. Our results highlight that oyster nuts oil stability should be improved before storage. Likewise, in lower elevations associated with high temperature and low precipitation, oyster nuts' quality is optimized. Hence, oyster nuts can improve nutritional status and income generation to farmers and communities in Tanzania.
Variations in nutrient composition of oyster nuts (Telfairia pedata) across different agro-climatic conditions
(Taylor & Francis Online, 2021-04-27) Mwakasege, Emmanuel; Treydte, Anna; Hoeglinger, Otmar; Kassim, Neema; Makule, Edna
In sub-Saharan Africa, nutrient deficiency remains a challenge. The challenge is partly due to the underutilization of available local nutrient sources and failure to optimize nutrients based on agro-climatic conditions. This study investigated the nutrient composition and variations in the underutilized oyster nuts (Telfairia pedata) from different sites and elevation levels encompassing different agro-climatic conditions. Fats were the most abundant contents of the nuts with 68%, followed by 25% protein, 5% carbohydrates, and 2% ash. Fatty acid contents were dominated by linoleic acid (47%), while magnesium was 150 mg/100 g, the most abundant mineral element. Protein and fat contents increased significantly with declining elevations, while sites did not show any significant effects, except for oleic acids. These were higher in Tanga compared to Kilimanjaro and Arusha sites. In contrast, linoleic acids and minerals such as magnesium (Mg) and phosphorus (P) decreased significantly in low elevations. Other nutrients such as carbohydrates, potassium (K), calcium (Ca), iron (Fe), palmitic acid, and stearic acid were not significantly affected by site nor elevations. Our results highlight that, particularly in lower elevations associated with high temperature and high precipitation, oyster nuts’ quality is optimized and can contribute to reducing micronutrient deficiency and improve local communities’ nutritional status in sub-Saharan Africa.