Determination of Mineral Content in Commonly Consumed Leafy Vegetables

Determination of Mineral Content in Commonly Consumed Leafy VegetablesSushanta Borah&Ananta M.Baruah&Arup K.Das&Junmoni BorahReceived:11September2008/Accepted:27October2008/Published online:19November2008#Springer Science+Business Media,LLC2008Abstract Vegetables used by the people of Assam(India) found to be highly nutritious to maintain general balance diet.Nutritional information is used increasingly by public agencies and agricultural industries to promote different traditional fresh product.The work aimed at determining few nutritionally important minerals(calcium,iron,magnesium, phosphorus,and potassium)in leafy green vegetables widely consumed in Assam.The objective of the present work was to examine the variability in the mineral content. Keywords Commonly Consumed Leafy Vegetables. Micronutrients.Mineral Deficiency.AssamIntroductionPlant foods have almost all of the mineral and organic nutrients established as essential for human nutrition.Traditional vegetables contain a number of organic photo-chemical that have been linked to the promotion of good health.Potassium-rich food is generally used to treat or cure rheumatoid arthritis,but it is desirable to know which foods are high in potassium content.It is not sufficient to know the amount of potassium in a given weight of food.How much food we eat is largely determined by the number of calories contained in it.We eat until our appetite is sated by a sufficient intake of food energy,and then we tend to lose our appetite.Therefore,information on potassium in foods is much more useful if it is expressed as weight of potassium per calorie(Weber1974)Vegetables hold an important position in well-balanced diets.Green leafy vegetables are believed to occupy a modest place as a source of trace elements due to their high water content(Gibson1994).Nutritional information is used increasingly by public agencies and agricultural industries to promote fresh product.People are looking for variety in their diets and are aware of the health benefits of fresh fruits and vegetables.They have special interest in food sources rich in antioxidant vitamins (vitamins C,A,and E),calcium(Ca),magnesium(Mg), and potassium(K)and fiber.Most of these nutrient requirements can be solved by increasing the consumption of fresh vegetables.In addition to meeting nutrient intake levels,better consumption of fruits and vegetables is associated with reduced risk of cardiovascular disease and stroke(Gillman1995)It is important that iron is an essential mineral and a vital component of proteins involved in oxygen transport and metabolism.Iron is also an essential cofactor in the synthesis of neurotransmitters such as dopamine,or epinephrine,and serotonin.About15%of the body’s iron is stored for future needs and mobilized when dietary intake is inadequate.(Aberoumand and Deokule2008).Food Anal.Methods(2009)2:226–230DOI10.1007/s12161-008-9062-zS.Borah(*)Deaprtment of Botany,Chaiduar College,Gohpur,Sonitpur,Assam,Indiae-mail:Sushanta.borah@A.M.BaruahDepartment of Biochemistry&Agricultural Chemistry,BNCA, Assam Agricultural University,Chariali-784176,Sonitpur,Assam,IndiaA.K.DasDepartment of Botany,Rajiv Gandhi University,Arunachal Pradesh,IndiaJ.BorahKalabari Kala Niketon,Kalabari,Sonitpur,Assam,IndiaMagnesium deficiency can affect a wide variety of medical disorders including high blood pressure,asthma,angina pectoris,coronary artery disease,cardiac arrhythmias,chronic fatigue syndrome,all types of musculoskeletal disorders,epilepsy,mitral valve prolapse,anxiety,panic disorder,and many other medical and psychiatric conditions.(Schachter 1996).In edible plant sources,there are concentration variations of these dietary constituents.Research is under way to under-stand the physiological,biochemical,and molecular mecha-nisms that contribute to their transport,synthesis,and accumulation in plants (Grusak and Penna 1999).This knowledge can be used to develop strategies with which to manipulate crop plants and thereby improve their nutritional quality.Human diets should provide sufficient nutrients for maintenance,growth,and body functions (Larsen et al.2003).On playing physiological action,magnesium is the second most abundant intracellular cation.Magnesiumplays an essential physiological role in many functions of the body.Magnesium has the ability to compete with calcium for binding sites on proteins and membranes.An analysis focuses on the plant nutritional physiology and biochemistry of some essential human nutrients to provide examples of the type of information that is needed and to improve the mineral or organic nutrient consumption from vegetables (Swaminathan 2003).The amount varies from plant to plant and the season of occurrence of natural vegetables (Misra et al.2008).Phosphorus performs a numerous normal physiologic functions including skeletal development,mineral metabo-lism,energy transfer through mitochondrial metabolism,cell membrane phospholipid content and function,cell signaling,and even platelet aggregation.Because of its importance,normal homeostasis maintains serum concen-trations between 2.5to 4.5mg/dl (Moe 2008).The present work is aimed at determining the five nutritionally important minerals (calcium,iron,magnesium,12345678910A . se s s i l i sA . s p i n os u sA . v i r i di s C . oc c ide n t a l i s C . a s i a t i c a C . a l b u m C . e s c u l e n t a E . pr o s t r a t a E . f o e t i d u m H . s i bt h o r p i o d e sL . i n d i c a O . co r y m b o s a O . c o r n i c u l a t a P . c h i n e n s e P . a q u i l i n u mFig.1Ash g/100g1002003004005006007008009001000A . s e s s i l i s A . s p i n o s u s A . v i r i d is C . o c c i d e n t a l i s C . a s i a t i c a C . a l b u m C . e s c u l e n t a E . p r o s t r a t a E . f o e t i d u m H . s i bt h o r p i o d e sL . i n d i c a O . c o r y m b o s a O . co r n i c u l a t a P . c h i n e n s e P . a q u i l i n u mFig.2Calcium and magnesium content per gramphosphorus,and potassium)in green leafy vegetables widely consumed in Assam (India).The objective of the present work is to examine the variability in the mineral content by which people found to maintain a well-balanced diet.Materials and Methods Samples PreparationWe use samples collected from these plants in flowering and fruiting condition for the correct botanical identifica-tion.We selected healthy and disease-free edible parts of vegetables to assess total element contents.Fresh vegetables were cleaned with water and external moisture wiped out with tissue paper.The edible parts of the individual vegetables were separated and dried in a hot air oven at 50°C for 1h.The dried samples were then powdered in a blender for further study.Some leafy vegetables like Alternanthera sessilis ,Oxalis corniculata ,and Polygonum chinense were dried under shade to prevent the decomposition of chemical compounds present in them (Makkar 2003;Orech et al.2007).Chemical AnalysisThe major elements,comprising calcium,phosphorus,potas-sium and magnesium,and trace elements like ironwere10203040506070A . s e s s i l i s A . s p i n o s u s A . v i r i d i s C . o c ci d e n t a l i s C . a s i a t i c a C . a l b u m C . e s c u l e n t a E . pr o s t r a t a E . f o e t i d u mH . s i b t h o r p i o d e s L . i n d i c a O . co r y m b o s a O . c o r n i c u l a t a P . c h i n e n s e P . a q u i l i n u mFig.3Iron,potassium,and phosphorous content per gramTable 1Determination of essential minerals in commonly consumed leafy vegetables in AssamName of the vegetables FamilyLocal name Moisture (%)Ash (g %)Calcium (mg/g)Magnesium (mg/g)Iron (mg/g)Potassium (mg/g)Phosphorus (mg/g)1Alternanthera sessilis Amaranthaceae Matikaduri 87.407.4062121525.4213.2542Amaranthus spinosusAmaranthaceae Hati Khootaria 74.408.6087562124.6116.6603Amaranthus viridis Amaranthaceae Khootaria 76.618.2148032520.2614.3574Cassia occidentalis Leguminoseae Medeluwa 72.537.8057624723.7717.2625Centrella asiatica Umbelliferae Bor Manimuni 77.34 6.4142530119.5618.0596Chenopodium albumChenopodiaceae Jilmil74.528.1567237018.7617.5617Colocasia esculenta Araceae Kochu 82.60 6.7162824718.2212.10518Eclipta prostrata Astericeae Keheraj 77.728.0264642724.8617.4629Eryngium foetidum Umbelliferae Man Dhania 72.568.4151230824.2611.265810Hydrocotyl sibthorpiodes Umbelliferae Saru Manimuni 78.237.0041026319.2417.234911Leucas indica Labiateae Doron 78.507.1246831122.6616.445412Oldenlandia corymbosaRubiaceae Bonjaluk 74.778.1139621624.7314.336013Oxalis corniculata Oxalidaceae Saru Tengeshi 76.26 6.4249727418.7411.425714Polygonum chinense Polygonaceae Modhu Soleng 89.00 6.2152125518.2116.564815Pteridium aquilinumDennstaedtiaceaeDhekia84.227.1554732919.7614.2357determined by different methods.The ash content was determined by combusting the plant materials(AOAC 1990).The ash,thus prepared,was used for estimation of Ca and K by flamephotometry method(Baruah and Borah 1998).Standard colorimetric methods were employed for magnesium(Piper1950),phosphorus,and iron(Thimmaiah 1999).According to the method,the resultant ash was dissolved in5ml of HNO3/HCl/H2O(1:2:3)and heated gently on a hot plate until brown fumes disappeared.For the remaining material in each crucible,5ml of deionized water was added and heated until a colorless solution formed.The mineral solution in each crucible was transferred into a100-ml volumetric flask by filtration through Whatman filter paper,and the volume was made to the mark with deionized water.This solution was used for elemental analysisResults and DiscussionThe mineral composition in terms of ash,Ca,Mg,Fe,K,and P revealed that these traditional vegetables were sufficiently rich in mineral content,and the amount were much higher than many traditional vegetables of hilly areas of this region (Longvah2000).The ash content varied from6.21in P. chinense to8.6in Amaranthus spinosus(Fig.1).The mineral contents in these15vegetables showed that calcium was the most abundant macroelement present,ranging from 875mg/g(A.spinosus)to396mg/g(Oldenlandia corym-bosa)(Fig.2).This is followed closely by magnesium, which was present in the amount ranging from621mg/g(A. spinosus)to215mg/g(A.sessilis)(Fig.3).The Ca content was found to be higher than Mg in all the vegetables studied.Phosphorus was present in the amount ranging from 62mg/g(Cassia occidentalis and Eclipta prostrata)to 48mg/g(P.chinense)(Fig.2).Potassium content was highest in Centrella asiatica(18mg/g)and lowest in Eryngium foetidum(11.26mg/g).Trace element iron was found highest at25.42mg/g(A.sessilis)and lowest amount at18.21mg/g(P.chinense)(Table1).Because of the high iron content found in A.sessilis to cure anemia-tic problems, this plant was extensively used not only as vegetable but also as medicinal plant for liver and stomach ailments.The amounts of different minerals present in our observed vegetables are equivalent to internationally approved dietary needs to different human categories as milligram per day in different regions of the world(Aberoumand2008).No doubt,green leafy vegetables contribute significantly to the overall micronutrient intakes,mostly vitamins and calcium and iron.Perhaps,due to the long association of the local people of this region with the vast natural flora and fauna,the occurrence and prevalence of malnutritional diseases associated with micronutrients,such as anemia, night-blindness,and goiter,are comparatively less in this region compared to the national average(Toteja and Singh 2004).The varieties of green leafy vegetables consumed by the people of this region have always been harvested wild, and no effort has been made to cultivate these varieties on a commercial scale.The findings of chemical determination of these vegeta-bles are comparable with some other traditional vegetables of hilly regions of Meghalayas(Murugkar and Pal2004; Murugkar2005).ConclusionsWith the growing urbanization,changes have occurred in food habits.The ancient tradition of gathering and consuming leafy vegetables by the local people is slowly on the decline.The high nutritional quality and unique taste of these vegetables are likely to be lost if these wild edibles are not documented biochemically.Therefore,it is now imperative that a nutritional,anti-nutritional,and analytical medicinal database of these vegetables is set up to retain the information of these unique species.ReferencesAOAC(1990)Official methods of analysis of Association of Official Agricultural Chemist,15th edn,Washington,DC Aberoumand A(2008)Nutritional evaluation of edible Portulaca oleracia as plant food.Food Anal Methods.doi:10.1007/s12161-008-9049-9Aberoumand A,Deokule SS(2008)Determination of elements profile of some wild edible plants.Food Anal Methods.doi:10.1007/ s12161-008-9038-zBaruah 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