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Research Article | DOI: https://doi.org/10.31579/2637-8914/119
1 Department of Science Laboratory Technology, University of Medical Sciences, PMB 536 Ondo-City, Ondo State, Nigeria.
2 Department of Pharmacology and Therapeutic, University of Medical Sciences, PMB 536 Ondo-City, Ondo State, Nigeria.
3 Department of Science Laboratory Technology, Rufus Giwa Polytechnic, PMB 1019 Owo, Ondo State, Nigeria.
*Corresponding Author: Jacob Olalekan Arawande, Department of Science Laboratory Technology, University of Medical Sciences, PMB 536 Ondo-City, Ondo State, Nigeria.
Citation: Jacob O. Arawande, Christianah O. Ayodele., Felix O. Afolabi., Ayodeji T. Adesuyi., Bamidele Imoukhuede., (2023), Evaluation of Extractive Values, Qualitative and Quantitative Phytochemical Constituents of Red Soko (Celosia Trigyna) and Green Soko (Celosia argentea), J. Nutrition and Food Processing, 6(2); DOI:10.31579/2637-8914/119
Copyright: © 2023, Jacob Olalekan Arawande. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received: 26 December 2022 | Accepted: 03 April 2023 | Published: 17 April 2023
Keywords: phytochemical; solvent, extractive values; red soko and green soko
Medicinal plants are indispensable sources of bioactive compounds and have proved to be stalwart ingredients for a wide range of applications. The potency of five different solvents in extracting bioactive constituents; qualitative and quantitative determination of phytochemicals of red soko and green soko were studied. The plant were cut into smaller pieces, air-dried, ground into powdery sample, sieved with 40 mm mesh size and properly labelled. Each sample was extracted using five different solvents (acetone, chloroform, ethyl acetate, methanol and water) at ratio 1: 10 for 72 h. Each solvent extract was screened for nine phytochemicals (flavonoid, carotenoid, phenol, oxalate, tannin, saponin, alkaloid, phytate and ascorbic acid). It was observed that the plant extract contained seven phytochemicals in both red and green soko. The highest extractive values and qualitative screening of phytochemicals in red soko and green soko were obtained in water and methanol extracts. Quantitative phytochemical analysis showed that there was higher content of saponin, phytate and ascorbic acid in the two vegetables. Red soko contained lower ascorbic acid, saponin, total phenol, total carotenoid, alkaloid and flavonoid than green soko while green soko had lower phytate and tannin than red soko. There was no significant difference (P˂0.05) in flavonoids, total carotenoid and alkaloid contents in red soko and in green soko there was no significant difference (P˂0.05) in total carotenoid and alkaloid contents.
Phytochemical means plant chemicals, and they are plant secondary metabolites which have little or no role in photosynthesis, respiration, or growth and development, but may accumulate in surprisingly highconcentrations (Crozier et al., 2010). Phytochemicals can be defined as plant-derived chemicals, which are beneficial to human health and disease prevention (Anderson, 2004). They give plants its colour, flavour, smell and are part of a plant’s natural defense system (disease resistance). Phytochemicals are bioactive, non-nutrient plant compounds that can be found in fruits, vegetables, grains and other plant foods that have been linked to reducing the risk of major degenerative diseases (Liu, 2004, Chivandi et al., 2015). Plant foods provide not only essential nutrients needed to sustain life, but also afford bioactivecompounds (phytochemicals) for health promotion anddisease prevention (Prior and Gu, 2005, Dykes and Rooney, 2007, Liu, 2013). Phytochemicals include phenolic compounds, alkaloids, nitrogen containing compounds,saponins, terpenoids, organosulfur compounds andcarotenoids (Liu, 2013). About 200,000 structures ofphytochemicals are known and there are close to 20,000 (10%) of them that have been identified as originating from fruits, vegetables, and grains (Oz and Kafkas, 2017). In cereals, phenolic compounds are the major phytochemical (Ndolo and Beta, 2014). The daily requirements for bio-available micronutrients and phytochemicals are obtained through the consumption of indigenous leafy vegetables (Uusiku et al., 2010), which are usually abundant during the rainy season. Indigenous leafy vegetables may be a rich source of phenolic compounds and other phytochemicals that contribute to the antioxidant activity in the diet (Uusiku et al., 2010), thus providing strong protective effects against major diseases associated with oxidative damage (Kaur and Kapoor, 2002).
Vegetables play an important role in human diets, as they support the normal functioning of the differentbody systems. They provide our cells with vitamins,minerals, fiber, essential oils and phytonutrients. Vegetables contain low amounts of fat and calories (Banerjee et al., 2012). Leaf vegetables came from very wide variety of plants and they are plants with edible leaves. Each of us knows lettuce and spinach, as well as mustard, but alsoearly springtime nettles are valuable source ofvitamin C. Green leafy vegetables are popularly usedfor food, being a rich source of b-carotene, ascorbicacid, minerals and dietary fiber. One of the mostpopular vegetable is lettuce. Lettuce is cultivatedworldwide, and is one the most consumed green leafyvegetables in the raw form for its taste and highnutritive value, being regarded as an important source of phytochemicals, including carotenoids, in the diet (Chang et al., 2013). Vegetables are the greatest sources of phytochemicals and facts have emerged that some anti-nutritional content of these vegetables have potentials in reducing some diseases in man (Chang et al., 2013). Some of these diseases include high blood pressure, heart attack, stroke and other cardiovascular diseases (Williamson et al., 1997). Leafy vegetables are natural source of antioxidants and rich in phytochemicals (Elias et al., 2012, Raghavendra et al., 2013)
Celosia, Lagos spinach, is an important leaf vegetable for millions of households in sub-saharan Africa because of its multifaceted usefulness. In south-western Nigeria, it is known as “sokoyokoto” (Yoruba) (Grubben and Denton, 2004). The Celosia species is a genus and herbaceous of edible and ornamental plants of the family Amaranthaceae. The generic name isderived from the Greek word kelos, meaning "burned," and refers to the flame-like flower heads (Kai and Thomas, 2005). In Nigeria, six species of the genus Celosia have been described (IITA, 1972). The leaves and stems are cooked into soups, sauces or stew with other ingredients (Grubben and Denton, 2004). The leaves and tender stem of plumbed cockscomb (Celosia species) are consumed as a vegetable and the inflorescence eaten as a herb (Ilodibia et al., 2016; Olawuyi et al., 2016). Due to civilization, Celosia species are almost gone into extinction, therefore the focus of this research work is to determine the effectiveness of solvents in extracting the bioactive compounds in red soko and green soko as well as knowing which of the two vegetables is richer in phytochemicals with view of establishing their usefulness and gardening.
Source of materials
The plants (green soko and red soko) were collected from a local farms in Owo, Ondo State, Nigeria. All chemicals used were of the analytical grade with the highest purity available (>99.5%) and procured from Sigma Aldrich, USA.
Preparation and extraction of red soko and green soko
The plant materials (green soko and red soko) used were rinsed in water, cut into smaller pieces for easy drying, air-dried, ground and finally sieved to give 40 mm mesh size powder. They were put in air-tight containers and kept in a refrigerator at 40C prior to analysis. The powdered samples were divided into portions, packed in air tight containers labelled appropriately prior to extraction. Each sample was extracted separately with each solvent (acetone, chloroform, ethyl acetate, methanol and water) at ratio 1:10 for 72 h during which it was intermittently shaken on a shaking orbit machine The resulting mixture was filtered through a 0.45 μm nylon membrane filter. The extracts were desolventised to dryness under reduced pressure at 40 oC by a rotary evaporator (BUCHI Rotavapor, Model R-124, Germany). Weight of extract obtained was used to calculate the percentage yield (extractive value) of extract in each solvent and the dry extracts were stored in a refrigerator (4 0C) prior to analysis (Arawande and Aderibigbe, 2020; Arawande et al., 2018; Bopitiya and Madhujith, 2014).
Phytochemical analysis
Both qualitative and quantitative analyses were carried out. The presence of major phytochemical secondary metabolites, namely, saponins, alkaloids, flavonoids, tannins, phenolics, and terpenoids were determined using standard phytochemical methods with some modifications (Iqbal et al., 2015).
Qualitative determination of phytochemicals
Test for flavonoids (Cyanidine test)
This was done according to the method of Stankovic (2014). About 0.2 g of the plant sample/extract was added with 2 mL methanol and 1 mL of concentrated sulphuric acid added. A spatula was used to add a powder of magnesium chloride (MgCl2) and the mixture observed for 1 min for effervescence and also observed for a brick red colouration.
Test for phenol
Small quantity of the extract/ plant sample (about 0.5 g) was added to about 0.5 ml of FeCl3 solution. A deep bluish green solution was an indication for the presence of phenol (Sofowora, 2008).
Test for ascorbic acid
Plant samples/extract were crushed in acetic acid and filtered. Few drops of 2, 6-dichlorophenolindophenol solution to the 0.5ml of the filtrate. The presence of faint pink confirmed that ascorbic acid was present (Hunds et al., 1985)
Test for saponin
About 0.2 g of the extract/plant sample was shaken with 5ml of distilled water and then heated to boil. Frothing (appearance of creamy miss of small bubbles) showed the presence of saponin (Sofowora, 2008).
Test for tannin
About 0.2 g of plant sample/extract was stirred with 5 ml of distilled water and later filtered. Few drops of FeCl3 solution was added to 1ml of the filtrate. A blue-black green or blue green precipitate was an evidence for the presence of tannin (Sofowora, 2008).
Test for alkaloid
Test for alkaloids (Wagner's test). This was done according to the method of Joshi et al. (2013). About 0.2 g of the plant sample/extract was stirredwith 0.4 mL of 1% HCl in a water bath for 5 min and filtered. Two grams (2 g) of Potassium iodide and 1.27 g of iodine were dissolved in 5 mL of distilled water and the solution was diluted to 100 mL with distilled water. Two drops of this iodine solution were added to the filtrate; a brown coloured precipitate indicated the presence of alkaloids. (0.5 mL) of juice was added to 2 mL of glacial acetic acid containing two drop of ferric chloride. The set up was underplayed with 1 mL of concentrated sulphuric acid. It was observed for the appearance of violet and brownish rings below the interface, followed by the formation of a greenish ring in the acetic acid layer.
Test for oxalate
About 0.5 g of sample/extract was boiled with 1 ml of 2% H2SO4 solution on water bath. It was filtered while warm and few drops 1% KMNO4 was added. Pink colour confirms the presence of oxalate (Brindha et al., 1981).
Test for phytate
About 0.5 g of the sample/extract was mixed with 2 ml of 2% HCl solution. It was filtered and two drops of 0.3% ammonium thiocynate (NH4SCN) solution and 2 ml of distilled water were added and shaken. 3 to 4 drops of 10
Determination of flavonoids
0.50 g of finely ground sample was weighed into a 100 mL beaker, 80 mL of 95% ethanol was added and stirred with a glass rod to prevent lumping. The mixture was filtered through a What-man No. 1 filter paper into a 100 mL standard flask and made up to mark with ethanol. 1ml of the extract was pipetted into 50 mL standard flask, four drops of concentrated HCl was added via a dropping pipette after which 0.50 g of magnesium turnings was added to develop a magenta red coloration. Standard flavonoid solution of range 0 -20 ppm were prepared from 100 ppm stock solution and treated in a similar way with concentrated HCl and magnesium turnings as for the sample. The absorbance of magenta red coloration of sample and standard solutions were read on a digital Jenway V6300 Spectrophotometer at a wavelength of 520 nm. The flavonoid was calculated using the formula:
(ACOS, 2004)
Determination of total carotenoids
2 g of each sample was weighed into a flat bottom reflux; 10 mL of distilled water was added and shaken carefully to form a paste. 25 mL of alcoholic KOH solution was added and a reflux condenser attached. The above mixture was heated on a boiling water bath for 1hour during which it was carefully and frequently shaken. The mixture was cooled rapidly under tap water and 30 mL of water was added. The hydrolysate obtained was transferred into a separating funnel. The solution was re- extracted three times with 25 mL of chloroform. 2 g anhydrous Na2SO4 was added to the extract to remove any traces of water, the mixture was then filtered into 100 mL standard flask and made up to mark with chloroform. Standard solution of β- carotene vitamin A of range 0-50 g/mL were prepared with chloroform. The above gradients of different standard prepared were determined and the average gradient was taken to calculate vitamin A (β- carotene in µg/100g). Absorbance of sample and standard solutions were read on the spectrophotometer (Digital Spetronic 21D Spectrophotometer) at a wavelength of 329 nm.
Carotenoid (Vitamin A) ppm = Carotenoid (Vitamin A) µg/100g x 10-2 (AMC-RSC, 2002)
Conversion
6mg of β- carotene = 1 retinol equivalent
12mg of other Biological Active Carotenoids = 1: 1 Retinol equivalent
1 retinol equivalent of Vitamin A activity = 1mg retinol
1 retinol equivalent 3.I.U.
Determination of total phenol
About 0.20 g of sample was weighed into a 50 mL beaker, 20 mL of acetone was added and homogenized properly for 1 hour to prevent lumping. The mixture was filtered through a What man No.1 filter paper into 100 mL standard flask using acetone to rinse and made up to mark with distilled water with thorough mixing. 1 mL of sample extract was pipetted into 50 mL standard flask, 20 mL water was added, 3 mL of phosphomolybdic acid was added followed by the addition of 5 mL of 23% Na2CO3 and mixed thoroughly. The mixture was made up to mark with distilled water and allowed to stand for 10 minutes to develop bluish green colour. Standard phenol of concentration range 0-40 mg/L was prepared from 100 mg/L stock phenol solution from Sigma Aldrish Chemicals, U.S.A. The absorbance of the sample as well as that of the standard concentration of phenol was read after 30 minutes in 1cm cell on a digital Spectrophotometer at a wavelength of 510 nm. The total phenol in ppm was calculated thus:
(Iqbal et al., 2005)
Determination of oxalate
About 1 g of each sample was weighed into 250 mL conical flask and soaked with 100 mL of distilled water. They were allowed to stand for 3 hours and each was filtered through a double layer of filtered paper. Standard solution of oxalic acid range 0-40 ppm concentrations were prepared and read on a digital spectrophotometer at 420 nm in 1cm cell for absorbance. The absorbance of filtrate from each sample was also read.
(Iqbal et al., 2005)
Determination of tannin
1 g of each sample was weighed into a beaker. Each was soaked with solvent mixture (80 mL of acetone and 20 mL of glacial acetic acid) for 5 hours to extract tannin. The whole mixture was filtered through a double layer filter paper to obtain the filtrate. A set of standard solution of tannic acid was prepared ranging from 10 ppm to 50 ppm. The absorbance of the standard solution as well as that of the filtrates were read in 1cm cell at 760 nm in a digital spectrophotometer.
(Onwuka., 2005).
Determination of saponin
1 g of finely ground sample was weighed into a 250 mL beaker and 100 mL of isobutyl alcohol was added. The mixture was shaken on a UDY shaker for 5 hours to ensure uniform mixing. Thereafter the mixture was filtered through What man No 1 filter paper into a 100 mL beaker and 20 mL of 40% w/v saturated magnesium trioxocarbonate (iv) solution was added. The mixture obtained with saturated magnesium trioxocarbonate (iv) solution was again filtered through What man No.1 filter paper to obtain a clear colourless solution. 1 mL of colourless solution was pipetted into 50 mL volumetric flask and 2 mL; of 5% w/v FeCl3 solution was added and made up to mark with distilled water. It was allowed to stand for 30 minutes for blood red colour to develop. 0-50 ppm standard saponin solution were prepared from 1000 ppm saponin stock solution. The standard solutions were treated similarly with 2 mL of 5
| Samples | Acetone | Chloroform | Ethylacetate | Methanol | Water |
| Red soko (%) | 0.94a±0.01 | 1.98b±0.03 | 0.58a±0.00 | 5.50c±0.09 | 5.91c±0.11 |
| Green soko (%) | 0.39a±0.00 | 1.50b±0.01 | 1.49b±0.03 | 5.39c±0.11 | 7.81c±0.14 |
NOTE: Within each row, mean values followed by the same superscript are not significantly different at P˂0.05 level according to Duncan’s New Multiple Range Test (DMRT); Values represent means of triplicate determination ±standard deviation
Table 1: Extractive values (% yield) of red soko and green soko in different solvents
The extractive values (% yield) of red soko and green soko in different solvents is presented in Table 1. The percentage yield of red soko extract in acetone, chloroform, ethylacetate, methanol and water were 0.94±0.01%, 1.98±0.03%, 0.58±0.00%, 5.50±0.09% and 5.91±0.11
There was slight difference in phytochemical profile of red soko and green soko and this was also dependent on the nature of the solvents used for extraction. Methanol and water had the highest extractive values for red soko and green soko. Both vegetables were very rich in ascorbic acid, phytate and saponin but green soko was richer in ascorbic acid, saponin, total phenol, total carotenoid, alkaloid and flavonoid than red soko. Red soko had higher phytate and tannin than green soko. Nutritionally, green soko is slightly richer in phytochemicals than red soko.
Journal of Clinical Cardiology and Cardiovascular Intervention The submission and review process was adequate. However I think that the publication total value should have been enlightened in early fases. Thank you for all.
