Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2008.1365.1369Abbasi NiakousariM. 1020081110The aim of this research was to determine shelf life stability of
un-pasteurized lemon juice filled in clear or dark green glass bottles.
Presence of light, time and temperature affect the ascorbic acid retention
in citrus juices. Bottles were stored at room temperature (27 ± 3 °C)
and in the refrigerator (3 ± 1 °C). Total soluble solids, total
titrable acidity and pH value were measured every three weeks and analysis
was carried out on ascorbic acid content by means of titration method
in the presence of 2,6-dichlorophenol indophenol. The study was carried
out for 12 weeks after which slight changes in color, taste and apparent
texture in some samples were observed and ascorbic acid content reduced
by 50%. Soluble solids content, pH value and total acidity were 5.5 °
Brix, 2.73 and 5 g/100 mL, respectively which appeared not to be significantly
influenced by storage time or conditions. Ascorbic acid content initially
at 38.50 mg/100 mL was sharply reduced to about 22 mg/100 mL within the
first three weeks of storage. The final ascorbic acid content of all samples
was about 15 mg/100 mL. The deteriorative reaction of ascorbic acid in
the juice at all conditions followed a first-order kinetic model with
activation energy of 137 cal mol-1.]]>AOAC, 197512th Edn.,pp: 811-817pp: 811-817Burdurlu, H.S., N. Koca and F. Karadeniz, 200674211216Choi, M.H., G.H. Kim and H.S. Lee, 2002Citrus sinensis) juice during refrigerated storage.]]>35753759Handwerk, R.L. and R.L. Coleman, 198836231236Kabasakalis, V., D. Siopidou and E. Moshatou, 200070325328Kavousi, C.K.,19971997Kennedy, J.F., Z.S. Rivera, L.L. Lloyd, F.P. Warner and K. Jumel, 199245327331Kimball, D.A., 1991Labuza, T.P. and D. Riboz, 1982396674Laing, B.M., D.L. Schlueter and T.P. Labuza, 19874314401443Lee, H.S. and S. Nagy, 198853168172Nagy, S., 198028818Polydera, A.C., N.G. Stoforos and P.S. Taoukis, 2003602129Robertson, G.L. and C.M.L. Samaniego, 198651184187Rouse, A.H. and C.D. Atkins, 195263291294Rassis, D. and I.S. Saguy, 199528285290Soares, N.F.F. and H. Hotchkiss,199912111118Toledo, R.T.,19915th Edn.,Williams, P.G., H. Ross and J.C. Brand,199560541546Zerdin, K., L.M. Rooney and J. Vermue,200382387395