COOKING IN THE WATER EFFECT ON SOME WILD YAM SPECIES TUBER

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1 International Journal of Euation an Researh Vol. 1 No. 2 February 2013 COOKING IN THE WATER EFFECT ON SOME WILD YAM SPECIES TUBER A. SAHORÉ 1* : N G AMANI 1 1 Foo Sienes an tehnology epartment of Nangui Abrogoua University, 02 BP 801 Abijan 02, Côte Ivoire ABSTRACT The tubers of some wil yam speies (eight) foun in the Ivory Coast forest were ollete an effet of their ooking in the Water aoring to their nutrients an antinutritional fators was stuie. After this hyrothermal proessing of the wil yam tubers, the ontent of moisture, lipi, soluble sugar inrease an the ontent of protein, total arbohyrate, ellulose, ash erease. Nutrient ontents varie ifferently. The analysis of variane realize showe that the ooking oes not seem to have egrae signifiantly the nutrients exepte the remarkable inrease of the rate of sugars. The effet of hyrothermal treatment has not signifiantly hange the nutritional value of wil yam tubers stuie. The antinutritional fators varie ifferently in the tubers after ooking in boiling water: the yanogeni substane is partially estroye; Alkalois were soluble in water. The reution of the sapogenins ontent after the hyrothermal treatment seeme remarkable oxali ai was an organi ai whih eompose by heating. The antinutritional fators ontents erease signifiantly after ooking proess. KEYWORDS: wil yam, nutrients, antinutritional fators, ooking, Water, variane INTRODUCTION The yam was a tuber eonomially preious that only three areas of the worl ultivate extensively: Western Afria, the Caribbean an Southeast Asia. Worl proution of yam was 38 million tonnes per year. Exluing China as global proution of yams for Asia an Oeania represente only 1.5%. Ninety-six perent (96%) of worl proution ame from West Afria, partiularly in the area between the Ivory Coast an Cameroon. (Asieu, 1991; FAO, 2002). Next to ultivate yams there were also spontaneous yams. the yam speies that grew in the wil an whih were still the subjet of gathering attene everywhere in Afria where they are also use in foo as a ultivate speies (Hamon et al., 1995), but these tubers ontaine sometimes lethal amounts 1

2 ISSN: (Print) ISSN: (Online) of toxi priniples an inigestive. Yam in general an its wil forms in partiular ontaine varying amounts of hemial substanes (alkalois, tannins, sapogenins, polyphenols, phytates, oxalates, et...). If some of these substanes were only a bitter taste to the tubers after ooking, others suh as the alkalois were toxi an antinutrients (Coursey an Russull, 1969; Webster et al., 1984). These alkalois, when they are ingeste an ause serious symptoms, even mortals. Several authors announe ases of eath per onseutive poisoning to the onsumption of the tubers of the wil varieties of umetorum (Coursey, 1983; Hlaik et al., 1984). It is neessary that these wil tubers are treate to reue or estroy the toxi substanes for a better onsumption (Dumont et al, 1994). The loal populations whih were onsious of the potential risks relate to the onsumption of suh tubers whih onstitute nevertheless useful reserves uring the time of famine or foo shortage use often inappropriate tehniques of traitional treatment to eliminate if it was neessary the nutritional anti substanes of the tubers. It seeme important to know the hemial omposition of these prouts. The objetive of our stuy was to show the variation of reution of the nutrients an the antinutritional fators in the tubers subjete to a treatment of ooking to water. It is a question for that of making ook with water the tubers of the speies of wil yam an of omparing their omposition before an after ooking with water. MATERIAL AND METHODS Material vegetable The vegetable material is ompose of various wil yam speies tubers (yam speies not ultivate, but ollete in a wil state). These tubers of yam were harveste in July an August in the Ivory Coast forest zone. Partiularly in the region of Memni, 80 km from Abijan. Samples were ientifie by the Abijan Cooy University Floral Institute. They were the tubers of the following wil yam speies minutiflora, hirtiflora, bulbifera bulbil, burkilliana, bulbifera tuber, umetorum, praehensilis, mangenotiana. The wil yam speies tubers were preserve in the laboratory one ay after harveste. They were proesse into flour that was onitione in glass jars an store in the refrigerator. Preparation of flours The flours preparation onsiste of grining an sifting the pulp of ehyrate yam (Asieu, 1991). The ollete tubers are free of spines an roots, an then washe to eliminate the mu whih overe them. After this operation two types of flours are prepare: the flour an the ooke flour.

3 International Journal of Euation an Researh Vol. 1 No. 2 February 2013 Preparation of flour One or two of eah wil yam speies tubers, was leane an peele. The pulp was then immerse in water sulphite (0.1%) an ut into 1m piees. The piees of pulp were then rie 24 hours in a ventilate oven at 45ºC. Then they were rushe an sieve, fine flour (250 µ) of yam obtaine was use for some analyzes. Preparation ooke flour One or two kilograms, of tubers of eah speies, were washe, ut into 5m piees an ooke in boiling water for 20 minutes. After ooling the ooke yam piees are peele an ut into 1 m piees. The piees are rie an proesse into flour as in the ase of flour. The flours obtaine are pakage in jars an store in a refrigerator until use for analysis Chemial Analysis Moisture ontent 5 g of the fresh yam pulp were plae in an oven at 105ºC uring 24 hours until onstant weight an the amount of water evaporate is etermine after weighing (A.O.A.C,1980 ) Ash ontent After etermining moisture ontent, ry sample obtaine was ininerate at 550ºC in a muffle furnae. This temperature was maintaine until obtaining ashes without organi partiles. After ooling ashes in esiators, they are weighe immeiately (A.O.A.C, 1980) Proteins ontent Crue protein ontent was etermine from osage of total nitrogen by Kjelahl metho (BIPEA, 1976). One gram of sample (yam flour) was mineralize at 400ºC for 2 hours in onentrate sulphuri ai (20 ml) in the presene of a atalyst (1g Selenite of soium + 1g opper sulphate + 20 G of potassium sulphate). Ten milliliters of mineral solution ae to 10 ml soium hyroxie solution (40%) were istille an the istillate ollete in 20 ml of bori ai was titrate with sulphuri ai (0.1 N) in the presene of a olore iniator mixe (methyl re an bromoresol green). With this metho, all nitrogen ompouns were assaye. The onversion of nitrogen to proteins was arrie out by a onversion fator of total nitrogen in proteins whih was 100/16 =

4 ISSN: (Print) ISSN: (Online) Lipi ontent Lipi ontent was etermine using the apparatus Soxhte System HT The extration solvent was iethyl ether (BIPEA, 1976). This osage of lipis was base on the priniple of solubilisation of fat in no polar organi solvent. The lipis ontaine in 3 g of the yam flour were entraine by 70 ml of iethyl ether at 119ºC. Extration was arrie by flux an reflux uring 65 min. Solvent was ollete an then lipis were reovere an weighe after removal of traes of the solvent in an oven at 130ºC for 30 minutes. Soluble arbohyrate ontent Soluble arbohyrate ontent (soluble sugars) was etermine by the ioine metho of Luff Shoorl (BIPEA, 1976). The sugars were extrate with water from 5 g of the yam flour an plae in the presene of Fehling's solution an potassium ioie (10 ml of KI solution 10% w / v). Ioine resulting from the reation was titrate with thiosulfate (0.1 N). The Table allowe the Luff Shoorl, with the volume of phosphate mae to etermine the soluble arbohyrate ontent of the sample Total arbohyrates ontent The sum of igestible an inigestible arbohyrates was evaluate by ifferene: (moisture ontent + fats ontent + proteins ontents + ashes ontent). The knowlege of the total arbohyrate ontent was neessary for the appliation of thermal oeffiients of Atwater an Rosa (1899). For the alulation of the energy value. Starh ontent To etermine the starh ontent we proee by estimation using 0.9 the onversion fator of the gluose in starh (J.O. L 248 /CEE n 900/2008). % Starh = 0, 9 {(% Total arbohyrate) (% Soluble arbohyrates + % Cellulose) Cellulose ontent The metho of Weene (AFNOR. NF V /1993) was use. Ai hyrolysis (200 ml of ai sulphuri N) an alkaline hyrolysis (200 ml of 0.3N soium hyroxie) of the proteins an igestible arbohyrates ontaine in 3 g of the yam flour were arrie out, an then the hyrolysate was egrease with aetone. The resiue was rie an weighe. After alination the weight of the ashes was subtrate

5 International Journal of Euation an Researh Vol. 1 No. 2 February 2013 Energy value The energy value was alulate by appliation of the thermal oeffiients of Atwater an Rosa (1899). with 4 alories for 1g of proteins; 9, 3 alories for 1g of lipis an 3, 75 alories for 1g of arbohyrates. The energy value (allus / 100 g) = 4 x % proteins + 9, 3 x % lipis + 3, 75 x % arbohyrates. Oxali ai ontent Oxali ai ontent was etermine by titrimetri proeure. 10 g of the sample were maerate to hot (60ºC) in 50 ml of boile istille water for 30 min shaking. The maerate was filtere on the filter an the filtrate reue to 200 ml in a grauate flask with boile istille water. Fifty milliliters of this solution taken in a 250 ml flask were ilute with 50 ml of boile water an titrate with a solution of soium hyroxie (0.1 N) in the presene of phenolphthalein. The result was expresse in millequivalents or g / 100 g of ai etermine in this ase oxali ai (Rahi, 1978). Oxali ai (HOOC-COOH) was an organi iai, it releases 2 equivalents (H+) in solution to a moleular weight of M = 90 g. One milliequivalent orrespone to 90 / (2 x 1000) = 0,045 g of oxali. Tannins ontent The tannin ontent was etermine by the metho of aiifie vanillin after soaking the sample in methanol (Burns, 1971). One gram (1g) of the sample was maerate in 50 ml of methanol uring 28 hours. In 1 ml of this solution ae the reagent Vanillin-HCl (5 ml) (reagent was use for the referene 100 % transmittane) an to rea the UV spetrophotometer at 500 nm. The tannin ontent was etermine by omparison to a solution of atehin. Hyroyani ai ontent The hyroyani ai ontent was etermine by the metho of alkalinity titration (Holleman an Aten, 1956). The sample (27g) was maerate in water (200 ml) for 18 hours. The maerate is istille by internment in water vapour an the istillate is ollete in a solution NaOH (5%). After iluting 100 ml of the istillate to 2/5, yanogeni ions of istillate were etermine by a titrate solution of silver nitrate (0.02 N) in the presene of potassium ioie 8 ml. It was neessary to plan a witness. Cyanogeni ions in aqueous solution omplexe silver ions. AgNO 3 moleule reate with two moleules of HCN representing 54 g of HCN for AgNO 3 solution with 1N in the ase of a solution. 5

6 ISSN: (Print) ISSN: (Online) Alkaloi ontent The alkalois of the sample were put into solution by maeration in a mixture of iethyl ether an hloroform an extrate by HCl (J.O. 371 L 0250 / CEE, 1998). 15 g of the sample were maerate in a mixture of iethyl ether (100 ml) an hloroform (50 ml) overnight an the alkalois put thus in solution were extrate with hyrohlori ai (0.3 N) an were preipitate by the silio-tungsti ai solution (10%). The preipitate was ininerate an the ashes were weighe. The alkaloi ontent of the essay was obtaine by multiplying the weight of the ashes by a fator 0.2. Alkalois ontent aounte for 20% weight of the ashes. Sapogenins ontent Usually the saponins by hyrolyzing gave the sapogenins. The prinipal sapogenins ontaine in yam were iosgenin. The extration of sapogenins from (5g) sample was mae by reflux boiling (30 min) in 50 ml of ethanol. The aloholi extrat was onentrate to syrup an hot hyrolyze with 10 ml of sulphuri ai (4 N) for 2 hours. Sapogenins whih preipitate were isolate by filtration. They were then rie an weighe (Asieu, 1991). Statistial Analysis The analysis of variane (ANOVA) at p<0.05 means an stanar eviations were arrie out to ompare the levels of nutrients an antinutritional fators in the tubers. RESULTS Cooking in water Effet on the nutrient The nutrient ompositions of the tubers before an after ooking are ompare in Table I. The moisture ontent of the ooke tubers range from 66.92% in mangenotiana to 85.90% in minutiflora with an average grae of 75.1%. It inrease in the tuber after ooking from 74.20% to 75.19%. An inrease of approximately 1%. The arbohyrate ontent of the ooke tubers range from 75.40% ry matter in mangenotiana to 86.77% ry matter in bulbifera tuber with an average of 82.06% ry matter. It erease on average from 82.47% ry matter to 82.06% ry matter in the tuber after ooking. A erease of approximately 1%. The protein ontent of the ooke tubers ranges from 6.15%.m in bulbifera tuber to 13.70%%.m in mangenotiana with an average ontent of 9.20% %.m. It erease in the tuber after ooking from 9.63%.m to 9.20%. A erease of 5%. The lipi ontent of the ooke tubers range from 3.28%.m in minutiflora to 4.89%.m in mangenotiana with an average ontent of 4.00% %.m. It inrease in the tuber after ooking from 3.59 %.m to 4.00%.m. An inrease of 11%.

7 International Journal of Euation an Researh Vol. 1 No. 2 February 2013 The total sugar ontent of the ooke tubers range from 4.06%.m in burkilliana to 6.64%.m in bulbifera bulbil with an average ontent of 5.17%.m. It inrease in the tuber after ooking from 2.73 %.m to 5.17%.m. An inrease of 90%. The ellulose ontent of ooke tuber range from 3.41%.m in praehensilis to 7.02%.m in mangenotiana with an average ontent of 4.35%.m. It erease in the tuber after ooking from 5.03%.m to 4.35%.m. A erease of 14%. The ash ontent of ooke tubers range from 2.61%.m in praehensilis ms to 6.01%.m in mangenotiana with an average ontent of 4.09%.m. It erease in the tuber after ooking from 4.29 %.m to 4.09%m. A erease of 5%. The energy value of ooke tubers range from 377 Cal / g 100.m in minutiflora to 389 Cal / g 100.m in praehensilis with an average of 384 Cal / g 100.m. It inrease in the tuber after ooking from 381Cal / 100g.m to 384 Cal / 100g.m. An inrease of approximately 1%. The analysis of variane of nutrient omposition showe no signifiant ifferene (p <0.05) between the nutrient ontent of tubers an Cooke (the values assigne iential letters in Table I are not signifiantly ifferent for ertain speies stuie in the following ases: the water ontent of bulbifera bulbil; praehensilis an mangenotiana - The protein ontent of hirtiflora, bulbifera bulbil; burkilliana, bulbifera tuber; praehensilis an mangenotiana - The total arbohyrate ontent of hirtiflora, bulbifera bulbil, burkilliana, bulbifera tuber; umetorum an mangenotiana - The ellulose ontent of minutiflora ; burkilliana; bulbifera tuber; praehensilis an mangenotiana - The ash ontent of minutiflora; burkilliana, bulbifera tuber an umetorum - The energy value of minutiflora, hirtiflora. burkilliana, bulbifera tuber; umetorum; mangenotiana an praehensilis Cooking in water effet on antinutritional fators The antinutritional fators ompositions of tubers before an after ooking are ompare in Table II. The hyroyani ai ontent of ooke tubers varie from 0.01 mg / kg.m in burkilliana, minutiflora to 0.15 mg / kg.m in umetorum, with an average ontent of mg / kg.m. After ooking the hyroyani ai ontent erease in the tuber from to mg / kg.m. A erease of 50%. Alkaloi ontent of ooke tubers range from mg / 100 g.m in minutiflora to mg / 100 g.m in bulbifera tuber, with an average ontent of mg / 100 g.m. After ooking, the alkaloi ontent erease in the tuber from mg to mg / 100 g.m. A erease of 30%. The sapogenins ontent of ooke tubers range from 0.01%.m in bulbifera tuber an mangenotiana 0.86%.m in hirtiflora, with an average ontent of 0.24%.m. After ooking, the sapogenin ontent erease in the tuber from 0.59 to 0.24%.m. A erease of 60%. The oxali ai ontent of ooke tubers range from 3.93 mg / 100 g ms in burkilliana to mg / 100 g ms in togoensis, with an average ontent of 7.37 mg / 100 g.m. After ooking, the amount of oxali ai erease the tuber of 9.01 to 7.37 mg / 100 g.m. A erease of 20%.The tannin ontent of ooke tubers range from mg / 100 g.m in hirtiflora to mg / 100 7

8 ISSN: (Print) ISSN: (Online) g.m in mangenotiana, with an average ontent of mg / 100 g.m. After ooking, the tannin ontent erease in the tuber from mg to mg / 100 g.m. A erease of 20%. The analysis of variane showe a signifiant ifferene between the levels of antinutritional fators tubers an Cooke respetively of eah wil yam speies stuie (values assigne iential letters in Table II are not signifiantly ifferent) DISCUSSION Cooking in water effet on the nutrients After the hyrothermal proessing of the wil yam tubers we notie: That the moisture ontent slightly inrease in a 1 % proportion approximately. This inrease of the moisture ontent in tubers seems very low but ases of weak inrease of the quantity of water in the tubers uring the ooking, were observe by Favier et al ( 1971 ) in the roots of assava ; Bell ( 1981 ) in tubers of yam an Haraa et al ( 1985 ) in tubers of potato. The protein ontent in tubers erease in a 5 % proportion, aoring to Bell (1981), protein ontents in the ooke tubers of yam woul be from 6 to 11 % lower than those of the tubers of yam. Our results thus seem to approah those of Bell (1981). The erease of the protein ontent in tubers, uring the ooking with water, woul be ue to a loss of the nitrogenous material by solubilisation (Trèhe, 1989). The lipi ontent in tubers inrease to 11 %. This inrease notie by the lipi ontent woul an ue to a istribution of lipi from the skin towars the pulp of yam. It woul be also possible that this inrease of lipi relate to the moe of ooking in the boiling water of tubers with the skin whih we use. The soluble sugar ontent in tubers varie. It has inrease from 90% in proportion. This value is higher than the 50% obtaine by Daié et al (1998) for tubers of sweet potato. This behaviour tuber, usually in hyrothermal treatments oul be explaine by the hyrolysis that ours in tubers transforming arbohyrates an starh in partiular, soluble sugars (Trèhe, 1989; Daié et al, 1998). The total arbohyrate ontent was varie. It has slightly erease in a proportion of 1%. This shows that the hyrothermal treatment oes not seem too egrae arbohyrates. Cellulose ontent varie in the tubers. It erease in a proportion of 14%. Holleman an Aten (1956) also observe suh reation of ellulose in ooke assava roots, whih might be ue to enzymati hyrolysis of ellulose uring the ooking water. Ash ontent varie in the tubers. The proportion of variation is own about 5%. Bell (1985) also foun a slight erease in ash ontent uring the ooking water yam tubers. It woul be ue to a loss of mineral elements; Energy value inrease in a 1 % proportion. The weak inrease of the energy oul be relate to the inrease of the lipi ontent whih is involve in its alulation. Nutrient ontents varie ifferently. The analysis of variane realize showe that the ooking oes not seem to have egrae signifiantly the nutrients aepte the remarkable inrease of the rate of sugars. The effet of hyrothermal treatment has not signifiantly hange the nutritional value of wil yam tubers stuie

9 International Journal of Euation an Researh Vol. 1 No. 2 February 2013 Cooking in water effet on antinutritional fators The antinutritional fators varie ifferently in the tubers after ooking in boiling water (Table II). Hyroyani ai is a volatile ompoun (boiling point = 26 C) whih evaporates rapily in air at temperatures higher than 28 C an is easily issolve in water. The ooking in the water woul eliminate the free yanogeni substane. The yanogeni substane is partially estroye (50%) aoring to Esser (1986). Alkalois, with some exeptions, ontaine nitrogen in a heteroyli ring inlue. They strethe to be protonate in aqueous solution, exept in the ase where the nitrogen atom of the moleule was ajaent to an eletron with ing group, so they were soluble in water in the form of free bases at high ph (Multon, 1991). Sapogenins erive from the hyrolysis of saponins whih were glyosies omplex. The prinipal sapogenin of the yams woul be the iosgenin whih was a ompoun soluble in the organi solvents (Tsukamamoto an Ueno, 1936; Martin, 1969; Takea, 1972; Asieu, 1991; Rihter, 1993). The reution of the sapogenins ontent after the hyrothermal treatment seeme remarkable (60 %). The oxali ai was an organi iai whih eompose by heating (Conia, 1987). The erease of its ontent in the tubers oul be attribute to the eomposition proess. But the oxali ai ha a high affinity for alium with whih it forme a sparingly soluble salt. Tannins were ompouns polyphenoli whih ha a little high points of boiling. They were water-soluble ompouns but beyone a ertain moleular weight, they woul be insoluble in water an entirely no absorbable (Conia, 1987). The variane analysis showe a signifiant reution of the ontents of fators antinutritional in the ooke tubers from 20 to 60% in proportion; the tubers of the lass haraterize by sapogenins oul be best etoxiate after ooking the variable sapogenins being estroye to 60% by the hyrothermal treatment whereas the other fators are estroye only to 20 an 50%. Thus the tubers of the wil yam speies whih ontain less sapogenins relatively woul be etoxiate after the hyrothermal proessing CONCLUSION The variane analysis shows that the ompositions in nutrients of the wil yams i not seem varie signifiantly speies with another. The tubers ontain muh water. The ry matter of the tubers has a large arbohyrate fration an a remarkable ontent of proteins. The variane analysis shows a signifiant reution of the antinutritional fators ontents in the ooke tubers from 20 to 60% in proportion the antinutritional fators ontent is substantially reue by ooking in boiling water. What suppose that a total ooking with boiling water oul ertainly etoxiate the tubers of these yams an to make them possibly eible 9

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13 International Journal of Euation an Researh Vol. 1 No. 2 February 2013 Table I: Composition of wil yam speies tuber (% ry matter) Speies Sampl e nature moistu re % fm* Protei ns Lipi Solubles arbohyra te Total arbohyra te Cellulo se Cenr e Energi e (al/10 g minutiflora ooke hirtiflora ooke bulbifera bulbil burkilliana bulbifera tuber umetorum praehensilis mangenotia na ooke ooke ooke ooke ooke ooke 85,90i 84,95h 82,87g 81,89f 82,14f 80,44f g 73,06e 71,59 71,01 69,80 70,85 69,65 68,79b 68,05b 66,92a 66,24a 8,84 e 10,59g 10,00f g 9,55ef 8,38b f 8,82 e 7,74b 8,24b 6,15a 6,29a 9,48e 9,93fg 9,29e f 9,48ef 13,70h 14,18h 3,28a b 2,95a 3,93 3,35a b 4,53e 3,99 3,83b 3,26a b 3,84b 3,53b 3,69b 3,43a 4,02 3,61 4,89e 4,61e 4,54 2,37ab 4,09 1,42a 6,64 3,59b 4,06 2,34ab 4,74 2,26a 6,41 3,77 6,71 3,81 4,21 2,25a 83,14b 81,73b 81,86b 82,27b 82,89b 82,44b 83,35b 83,77b 86,77 86,87 83,82b 83,36b 84,09b 84,51b 75,40a 74,94a 4,28e 4,30e 4,10e 5,98g 5,28f 7,67i 3,39a 3,64ab 3,53ab 3,71ab 3,82b 4,03e 3,41a 3,62ab 7,02h 7,33h 4,70e 4,76e 4,22 4,84e 4,22 4,74e 4,67e 4,73e 3,26 3,31 3,00b 3,27 2,61a 2,40a 6,01f 6,27g 377ab 376ab 383,53 377ab e ab b 386ab 384ab 389b 389b 383ab 380b 13

14 ISSN: (Print) ISSN: (Online) The iniate values represente the average of three eterminations (n = 3); ** in every olumn the values affete by ifferent letters were signifiantly ifferent in p < *fm: fresh matter Table II: Composition of wil yam speies tuber antinutritional fators Speies samples nature Oxali ai (mg/100g ms) Tanins (mg/100g ms) Hyroyani ai (10ˉ².mg/kgms Alkaloi (mg/100g ms) Sapogenins (% ms) umetorum ooke 9,03f 12,93j 493,60h 560,10i 14,95h 33,03j 127,63h 167,70m 0,34 0,78 togoensis ooke 11,03i 12,63j 387,83e 456,03g 0,99a 2,00b 161,03k 214,80q 0,40 1,49e minutiflora ooke 8,43e 10,03h 278,43b 385,73e 1,00a 2,00b 76,03a 101,03 0,24ab 0,90 bulbifera bulbil ooke 8,63e 9,33g 356,63 470,03gh 0,98a 1,97b 125,87g 165,63l 0,09ab 0,22ab mangenotiana ooke 7,50 9,03fg 495,73h 570,30i 1,03a 4,00 105,43 150,63j 0,01a 0,05ab praehensilis ooke 7,03 8,33e 319,03 410,73f 11,03g 20,03i 121,37f 175,70n 0,10ab 0,26b bulbifera tuber ooke 5,03b 6,83 345,83 421,00f 8,03e 10,03f 184,73o 248,23r 0,01a 0,08b hirtiflora ooke 5,73 6,50 255,63a 315,03 1,97b 7,00 80,73b 107,63e 0,86 1,34e burkilliana ooke 3,93a 5,43b 307,03 489,23h 1,00a 4,03 137,83i 187,03p 0,08ab 0,20ab The iniate values represente the average of three eterminations (n = 3); ** in every olumn the values affete by ifferent letters were signifiantly ifferent in p < 0. 05