American Journal of Plant Physiology1557-45391557-4547Academic Journals Inc.10.3923/ajpp.2013.63.73Solanum melongenas and Musa sapientum Fruits]]>ChikezieP.C. AkuwudikeA.R. ChikezieC.M. 2201382Enzyme activity depends largely on environmental conditions such as temperature
and pH. The stabilities of Polyphenol Oxidase (PPO) extracted from Solanum
melongenas and Musa sapientum fruits pre-incubated in varying thermal
and pH conditions were carried out. Enzyme activity was measured by spectrophotometric
methods. The reaction mixture contained 3.5 mL of 0.20 M phosphate buffer (pH
= 6.8), 1.0 mL of 0.75 mM catechol and 0.5 mL of enzyme solution. PPOS.
melongenas and PPOM. sapientum gave different temperature
and pH optima. The temperature-activity profile of PPOS. melongenasand PPOM. sapientum showed a strong positive correlation
(r = 0.907363). At pH = 10.0, PPOM. sapientum activity represented
65.3% decay in enzyme activity, whereas PPOS. melongenas represented
79.3% decay in enzyme activity. PPOS. melongenasand PPOM.
sapientum stability at pre-incubated temperatures of 20, 50 and 60°C
and pH values of 3.5, 6.0 and 8.0 were measured. Residual activities of PPOS.
melongenas and PPOM. sapientum showed a strong positive
correlations under the same experimental thermal conditions, with exception
at 20°C (r = 0.693375). Specifically, pre-incubation of PPOM. sapientum
for t = 90 min at 60°C caused 18.4% decay in relative activity of PPOM.
sapientum. At t = 90 min, pre-incubation of PPOM. sapientum,
in pH = 3.5 caused decay in activity within the range of 30.8-36.1%, whereas
PPOM. sapientum pre-incubated in pH = 6.0 and pH = 8.0 gave
decay in activity within the range of (1.5-9.8%) and (2.7-6.5%), respectively.
PPOS. melongenas and PPOM. sapientum showed
relatively higher stabilities as the incubation pH tended towards alkaline conditions,
whereas the two experimental temperatures (20 and 60°C) promoted destabilization.]]>Altunkaya, A. and V. Gokmen,201149249256Aylward, F. and D.R. Haisman,196917176Bello, A.B. and M.S. Sule,2012202731Bello, A.B., M.S. Sule and A.J. Alhassan,201142631Bradford, M.M.,197672248254Chikezie, P.C.,2006Cola nitida and Cola acuminata) and cocoa (Theobroma cacao).]]>4115124Da Silva, C.R. and M.G.B. Koblitz,2010Spondias spp.).]]>30790796Dogan, S. and M. Dogan,2004Thymus longicaulis subsp. chaubardii var. chaubardii),]]>886977Escobar, M.A., A. Shilling, P. Higgins, S.L. Uratsu and A.M. Dandekar,2008133852858Fawzy, A.M.,2005Malus Domestica Borkh.).]]>25629644Gaoa, Z.J., J.B. Liua and X.G. Xiaoa,2011Cleome gynandra L.]]>12910121018Gouzi, H., T. Coradin, E.N. Delicado, M.U. Unal and A. Benmansour,2010Agaricus bisporus (J.E. Lange) Imbach polyphenol oxidase.]]>317Gowda, L.R. and B. Paul,2002Dolichos lablab) polyphenol oxidase.]]>5016081614Jimenez-Atienzar M., J. Cabanes, F. Gandıa-Herrero and F. Garcıa-Carmona,2004319902910Kavrayan, D. and T. Aydemir,2001Mentha pipetita).]]>74147154Klabunde, T., C. Eicken, J.C Sacchettini and B. Krebs,1998510841090Lacki, K. and Z. Duvnjak,1999Trametes versicolor in the presence of canola meal.]]>1991100Liu, L., S. Cao, B. Xie, Z. Sun, X. Li and W. Miao,20075571407143Madani, I., P.M. Lee and L.K. Hung,2011Hibiscus rosa-sinensis L.]]>2011pp: 110114Mahmood, W.A., S.H. Sultan and S.R. Hamza,20092009Marcos, C., N.B. Riccardo and S. Giovanni,200856132138Marshall, M.R., J. Kim and C. Wei,2000Mayer, A.M.,20066723182331Mayer, M.A. and E. Harel,197918193215Mizobutsi, G.P., F.L. Finger, R.A. Ribeiro, R. Puschmann, G. Vieira and L.L. de Melo Neves,2010Litchi chinensis sonn.) pericarp.]]>864361366Nakamura, K., Y. Amano and M. Kagami,198334 122127Oktay, M., I. Kufreviolu, I. Kocacaliskan and H. Sakiroglu,199560494496Qudsieh, H.Y., S. Yusof, A. Osman and R.A. Rahman,2002Ssaccharum officinarum var. Yellow cane).]]>5016151618Rodwell, V.W. and P.J. Kennelly,20032003Selles-Marchart, S., J. Casado-Vela and R. Bru-Martinez,2006Eriobotrya japonica Lindl.): Kinetic characterization and comparison with the active form.]]>446175185Sommer, A., E. Ne'eman, J.C. Steffens, A.M. Mayer and E. Harel,199410513011311Steffens, J.C., E. Harel and M.D. Hunt,19941994pp: 275-312pp: 275-312Unal, U.M., O. Gokkaya and S. Sener,201136255262Yemenicioglu, A. and B. Cemeroglu,2003Prunus armeniaca L.): Evidence for the presence of thermostable PPO forming and destabilizing mechanisms in apricots.]]>5123712379Yemenicioglu, A., M. Ozkan and B. Cemeroglu,1999Colocasia antiquorum).]]>23425430Ying, Y. and W. Zhang,200843102107Yoruk, R. and M.R. Marshall,200327361422Zheng, Y., J. Shi and Z. Pan,2012234607616Ziyan, E. and S. Pekyardimic,2004Helianthus tuberosus).]]>27217225