QUANTITATIVE CHANGES OF ASCORBIC ACID AND BETA CAROTENE IN AFRICAN NIGHTSHADE (SOLANUM NIGRUM) AND SPIDER PLANT (CLEOME GYNANDRA) DUE TO TRADITIONAL COOKING METHODS USED IN WESTERN KENYA

10.37512/600 ◽  
2019 ◽  

African nightshade (Solanum nigrum) and Spider plant (Cleome gynandra) are among African leafy vegetables (ALVs) that are consumed in Kenya. Studies were conducted to establish the traditional cooking methods for ALVs and to determine quantitative changes in ascorbic acid and beta carotene on cooking the two ALVs. Results revealed that the cooking methods had distinct steps. The amount of time and water for cooking were unspecified. Ascorbic acid decreased from 28.2mg/100g to 1.8mg/100g in Spider plant (93.6% loss) and from 19.5mg/100g to 5.8mg/100g in African nightshade (70% loss). Beta carotene decreased from 2.1mg/100g to 0.1mg/100g in Spider plant (94.4% loss) and from 1.8mg/100g to 0.9mg/100g (50.6% loss) in African nightshade. All results were significant (P˂ 0.001). The study concludes that there are existing methods of cooking ALVs. For the two ALVs, cooking led to drastic losses of ascorbic acid and beta carotene. Losses from the African nightshade were generally lower than from the Spider plant for the same nutrient, under similar processing conditions. The study recommends procedural changes in processing methods so as to conserve the two nutrients.

2019 ◽  
pp. 1-17
Author(s):  
N. N. Umerah ◽  
N. M. Nnam

Background/Objective: Vegetables and fruits play a highly significant role in food security of the underprivileged in both urban and rural settings. The study was designed to determine the nutritional composition of some neglected underutilized fruits and vegetables in Southeast geopolitical zone of Nigeria. Methodology: The commonly occuring underutilized fruits and vegetables were selected for the study. The food crops were harvested and identified at the Herbarium in the Department of Plant Science and Biotechnology, University of Nigeria Nsukka. Twenty underutilized fruits and vegetables each were cleaned and analysed for nutrients composition using standard methods. Data were presented using descriptive statistics, percentage, mean, standard deviation and frequency. Results: The proximate composition of the fruits ranged from 54.34-80.30% moisture, 0.27-6.21% protein, 0-3.08% fat, 0.28-8.58 % fibre, 0.33-11.05% ash and 9.08-36.61% carbohydrate. The ranges for mineral values of the fruits were iron 0.10-9.60 mg, zinc 0.02-10.30 mg, manganese 0.10-6.60 mg and calcium 5.42-46.50 mg.  The vitamin contents of the fruits ranged from beta-carotene traces -5666.67 RE, ascorbic acid 0-48.82 mg and vitamin E 0 -11.99 mg. The proximate composition of the vegetables ranged from moisture 60.45-91.00%, protein 0.02-6.60%, fat 0.02-2.19%, fibre 0.04-5.01%, ash 0.04-4.20% and carbohydrate 10.30-36.61%. The ranges for mineral values of the vegetables were iron 1.40-14.80 mg, zinc trace-9.40 mg, manganese 0.07-4.80 mg and calcium 18.19-400.00 mg. The vitamin levels of the vegetables were beta-carotene 15.20-1933.33 RE, ascorbic acid 2.40-38.40 mg and vitamin E traces - 6.67 mg. Conclusion: The use of these fruits and vegetables should be encouraged particularly in areas where they are not produced through nutrition education in order to promote the food use of these crops.


Author(s):  
Makokha Grace ◽  
O. P. Owuor ◽  
D. M. K. Ongeri

Proper nutrition contributes to declines under-five mortality rates and improves the productivity of adults. Addressing nutritional problems requires adequate information on the diets of individuals and populations. African leafy vegetables (ALVs) are widely consumed and often harvested at different stages after planting with the help of different communities. Four ALVs namely Vigna unguiculata, Amaranthus hybridus, Cleome gynandra and Solanum scabrum are commonly grown vegetables in western Kenya, their potentials have not been evaluated to supply the nutrients. However, nutritional values may vary depending on the species, harvesting stage and location of production. The effects of species, harvesting stages and location of production on the nutritional value of selected ALVs were evaluated. The trials were laid out in a randomized complete block design in three replicates in Busia, Kisumu, and Lela. Leaves were sampled at different harvesting stages and analyzed for N, P, K, Na, Ca, Mg, Mn, Fe, and Zn levels. Amaranthus hybridus had significantly (P≤0.05) higher levels of P, Ca, Zn, Mn, and Na. The N, P, K, Ca, Mg, Zn and Fe levels significantly (P≤0.05) increased then decreased with harvesting stage. The levels of nutrients significantly (P≤0.05) varied with location of production except for Na. The ALVs from Kisumu site had significantly (P≤0.05) higher levels of N, P, K, Ca, Mg and Zn, ALVs from Lela site had higher levels of Mn and Na while ALVs from Busia site had higher levels of Fe. Amaranthus hybridus is a better contributor of-of P, Ca, Zn, Mn, and Na. The Fe, Mg and Zn levels were above the Recommended Dietary Allowance and may be used to alleviate deficiencies associated with such nutrients. Harvesting the ALVs at the stage the nutrients attain their optimum levels is recommended. There is a need for the development of regional food composition tables for all ALVs in Kenya.


2014 ◽  
Vol 14 (61) ◽  
pp. 8529-8544
Author(s):  
TN Tumwet ◽  
◽  
EK Kang’ethe ◽  
W Kogi-Makau ◽  
AM Mwangi

A survey was carried out to document the diversity and immune boosting claims of African indigenous leafy vegetables (AILVs) in Western Kenya. Both qualitative and quantitative methods of data collection were used. The results showed that there is diversity of AILVs in the study area with nine popular and frequently consumed, but cassava leaves, stinging nettle and russian comfry are not popular. Seven of these are cultivated but two, stinging nettle (Urtica massaica) and vine spinach (Basella alba) grow wildly. The AILVs are cultivated at subsistence level on home gardens with minimal inputs and only excess of this is sold. The religion one belonged to was significant (p<0.05) in determining consumption or not of some of the vegetables. The vegetables are rain fed and the process of harvesting is by first uprooting during thinning followed by breaking the main stem and finally plucking off the leaves with maturity. Vegetable preparation in most households was mainly by women. The elderly women were keen in this process and spent more time in preparing the vegetables which were believed to be ‘nutritious’. There was no processing and preservation of the AILVs for use during the dry season. The communities rely on wild weeds during such seasons. The AILVs though consumed for good nutrition are also associated with various medicinal and immune boosting claims. Out of the nine, five are known for various health benefits, African nightshade and spider plant for good nutrition by 31.8% and 25.1% of the respondents, respectively, slender leaf for healing power by 34%, cowpea leaves and slender leaf for anti-aging by 50% and 43.8%, respectively, and cowpea leaves (43.6%) and amaranthus (53%) for smooth skin and adding blood, respectively. Chi square analysis indicated that African night shade, spider plant and amaranthus are statistically significant (p<0.05) in contributing to good nutrition, healthy functioning of the body and immune boosting. Further analysis showed that spider plant and amaranthus are significant (p<0.05) for immune boosting.


Foods ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 35 ◽  
Author(s):  
Victoria Gowele ◽  
Joyce Kinabo ◽  
Theresia Jumbe ◽  
Carolyn Kirschmann ◽  
Jan Frank ◽  
...  

The essential micronutrients in indigenous leafy vegetables (ILVs) could substantially contribute to the micronutrient supply in rural communities in Tanzania, but concentrations differ between species. Provitamin A carotenoids, tocopherols, ascorbic acid, minerals, and phytate were analysed in 13 different species using HPLC-, ICP-OES, and photometric techniques. Eight of the 13 ILVs, including Amaranthus ssp. and Sesamum angustifolium, had high β-carotene concentrations (2.91–4.84 mg/100 g fresh weight), which could provide ≥50% of vitamin A’s recommended nutrient intake (RNI). Six ILVs including Cleome hirta and Sonchus luxurians had high iron contents (34.5–60.4 mg/100 g, >50% RNI); Amaranthus ssp. represented the ILV with high calcium, magnesium and zinc contents (85%, 207% and 21% of RNI per 100 g); Cleome hirta and Cleome gynandra had high ascorbic acid contents (>15 mg/100 g, 34–35% of RNI), while Sesamum angustifolium was the only ILV with a high tocopherol content (7.34 mg α-TE/100 g). The highest phytate concentration was found in Amaranthus ssp., which could negatively affect its role as a very good source of minerals. Results indicate that the analysed ILVs could make a substantial contribution to the vitamin A and iron supply in the diets of rural Tanzanian populations.


2020 ◽  
Vol 2020 ◽  
pp. 1-5 ◽  
Author(s):  
Gebrehana Ashine Hailemariam ◽  
Tadele Andargie Wudineh

Ascorbic acid is highly sensitive vitamin to various modes of cooking processes. Ethiopian green collards (Brassica carinata), locally called Ye’abesha Gomen, and cabbage (Brassica oleracea) are important green vegetables for ascorbic acid source in the country. The rate of ascorbic acid degradation in cabbage and Ethiopian green collard was studied employing two processing methods: open-pan and pressure cooking which are highly customized in household cooking. Samples were cooked at 5, 10, 15, 20, 25, 30, and 35 min under each processing method. Ascorbic acid concentration in each sample was determined by using a spectrophotometer at 520 nm wavelength using the standard plot of pure ascorbic acid solution. The initial concentration of ascorbic acid in fresh cabbage and Ethiopian green collard were found to be 33.76 ± 0.58 and 38.14 ± 0.19 mg/100 g, respectively. Well-cooked and edible Ethiopian green collard was obtained at 10 minutes of cooking time by pressure cooking with ascorbic acid retention of 31.8% from its initial contents. However, a cooking time of 25 min was required by the open-pan cooking method with 26.8% ascorbic acid retention. Edible cabbage was attained at 10 and 20 minutes of cooking time by pressure and open-pan cooking methods maintaining 36.9 and 30.9% of ascorbic acid, respectively. Thus, the pressure cooking method required short cooking time for having well-cooked and edible green leafy vegetable with better ascorbic acid retention. The outputs of this work would be helpful to design and control practical thermal processing situations and to minimize the loss of ascorbic acid in green leafy vegetables.


2021 ◽  
Vol 2 (1) ◽  
pp. 53-60
Author(s):  
J Mumbi ◽  
R Wanjau ◽  
J Murungi

Folate (vitamin B9,5-methyltetrahydrofolate) and ascorbic acid (AA) (vitamin C) play a key role in human health and wellbeing. It is greatly established that AA is beneficial in preventing scurvy while folate helps in prevention of neural tube defects and congenital malformations. The main sources of these vitamins are fruits and vegetables especially green leafy vegetables including the African Indigenous Vegetables (AIVs). However, these vegetables are consumed after cooking which leads to loss of the vitamins through oxidation, thermal degradation, and leaching. The study aimed at determining the effect of different cooking methods on the retention of AA and folate in cowpea (Vigna unguiculata L. Walp) as affected by different cooking methods. Folate and AA were determined using high pressure liquid chromatography with ultra UV-visible detection, HPLC-UV after extraction of the vitamins from raw and cooked samples. Analysis of Variance (ANOVA) was used to determine difference in nutrients retention by various cooking methods. Significance was imputed at p<0.05. Raw V. unguiculata ontained 45.516±0.649 mg/100g AA and 91.736±0.586 μg/100g folate. The cooked samples of the vegetable contained folate ranging from 40.713±0.081 to 65.128±0.007 μg/100g and AA ranging from 0.719±0.063 to 24.181±0.051 mg/100g of the edible portion of the vegetable. Cooking the vegetable significantly reduced both folate and AA concentration compared to the raw vegetable samples, p<0.05. Frying raw vegetables with onions and tomatoes was found to retain significant folate and AA than boiling the vegetables, p<0.05. Addition of milk resulted in significant retention of folate and significant loss of AA than boiling, p<0.05. Both lye and sodium bicarbonate significantly reduced folate and AA concentration than boiling, with lye causing significant reduction of both vitamins than sodium bicarbonate p<0.05. It is concluded that cooking reduces folate and AA concentration in cowpea (V. unguiculata L. Walp). Additive such as lye and bicarbonate also reduce the concentration of the vitamins. Cooking cowpea leaves with addition of milk and frying with onion and tomatoes retains more folate than boiling. However, AA is significantly lost in the process than when the vegetable is just boiled.


1998 ◽  
Vol 156 (3) ◽  
pp. 551-561 ◽  
Author(s):  
JF Mutaku ◽  
MC Many ◽  
I Colin ◽  
JF Denef ◽  
MF van den Hove

The effects of the vitamins dl-alpha-tocopherol, ascorbic acid and beta-carotene, free radical scavengers and lipid peroxidation inhibitors, were analyzed in male Wistar rats made goitrous by feeding a low iodine diet (< 20 micrograms iodine/kg) and perchlorate (1% in drinking water) for 4, 8, 16, and 32 days. Groups of control or goitrous rats received for at least 16 days before killing a diet containing 0.6% vitamin E (as dl-alpha-tocopherol acetate), 1.2% vitamin C (ascorbic acid) and 0.48% beta-carotene, either simultaneously (vitamin cocktail) or separately. This treatment led to a 5-fold increase of vitamin E in the thyroid gland, a 24-fold increase in the liver and a 3-fold increase in the plasma. In control rats, vitamin cocktail administration increased slightly the thyroid weight with little changes in thyroid function parameters. During iodine deficiency, administration of the vitamin cocktail or vitamin E alone reduced significantly the rate of increase in thyroid weight, and DNA and protein contents, as well as the proportion of [3H]thymidine labeled thyroid follicular cells, but not that of labeled endothelial cells. Plasma tri-iodothyronine, thyroxine, TSH levels, thyroid iodine content and concentration as well as relative volumes of glandular compartments were not modified. The proportion of necrotic cells rose from 0.5% in normal animals to about 2% after 16 days of goiter development. No significant protective effect of the vitamins was observed. These results suggest that these vitamins, particularly vitamin E, modulate one of the regulatory cascades involved in the control of thyroid follicular cell growth, without interfering with the proliferation of endothelial cells.


2020 ◽  
pp. 72-75
Author(s):  
I. T. Balashova ◽  
L. V. Bespalko ◽  
A. V. Molchanova ◽  
E. V. Pinchuk ◽  
N. E. Maschenko

Relevance. Vertical farming – is a new and advanced direction in greenhouse vegetable cultivation. Expansion biodiversity of plants for vertical farming occur with help of green leafy vegetables. Plants of Lamiaceae family are well known as aromatic and medicinal plants with high content of substances with antioxidant activity. It allows use these plants as a base for the functional nutrition. Leafy parts the plants of Lamiaceae family may be used as aromatic and healthy additions to traditional foods, such as salads, soups and sauces.  Goal of the study: analysis the biochemical composition of leafy parts plants of Lamiaceaefamily, cultivated at the multi circle hydroponic construction. Materials and methods. 1) Plants: Monarda fistulosa L. (the breeding sample №5 U.P.), Monarda citriodora Cerv. ex Lag. (Simka variety), Melissa officinalisL. (Zhemchuzhina variety). 2) secondary metabolites: flavonoid glycoside linarozid and steroid glycoside moldstim. Methods. 1) cultivation of plants Lamiaceae family at the 5 circles hydroponic construction; 2) analytic methods: determination of dry matter content, determination of ascorbic acid content, determination sum of chlorophylls and carotenoids, determination sum of antioxidants; 3) statistical methods. Results. First experiment the cultivation of plants Lamiaceae family at the multi circle hydroponic construction was successful. Location of plants at different circles of hydroponic installation didn’t influence the content of dry matter, ascorbic acid and sum of chlorophylls in leafy parts of plants Monarda fistulosaL. The content of dry matter and sum of antioxidants in leafy parts of Monarda fistulosaL. plants of the first cutting is significantly higher than of other cuttings. So, we can recommend the leaves of Monarda fistulosa L. plants of the first cutting for the healthy additions in the scheme of the functional nutrition. Seed treatment with water solutions of secondary metabolites changed significantly the weight of leaves: it was increased in Monarda citriodoraCerv. ex Lag. and in Melissa officinalisL. 


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