The Influence Of Priming Two Cucumber Cultivar Seeds

J. Duhok Univ. Vol.13, No.1, (Agri. And Vet. Sciences) Pp 139-147, 2010
EFFECT OF PACKAGING MATERIALS AND STORAGE ON
LOCAL ORANGE JUICE BY USING MODELS SYSTEMS
RAJAB.I. HAMEED.DUHOK
Technical Institute Duhok, Fundation of Technical Education-Erbil, Kurdistan Region-Iraq
(Received: September 23, 2010; Accepted for publication: March 10, 2011)
ABSTRACT
A model system of local orange juice 13% packaged in glass and plastic bottles and stored at 20,30 and 40 ° C for
four months in light and without light.Results showed that increasing temperature and period storage caused
decreasing in ascorbic acid content and increasing nonenzymatic browning,The stability of ascorbic acid and reduced
of nonenzymatic browning was better in the paked in glass bottles.The results of ascorbic acid degradation kinetic
parameter showed that the order of the reaction is First and there was an increasing in rate constant(K)in the case of
increasing of the storage temperature and in the samples of glass bottles,but the rate constant was decreased in the
stored dark.The activation energy(Ea) of samples stored in the light,and decrease in plastic bottles.It was found that
the shelf life of samples decreased with increasing the storage temperature .We got in this study the predication
equation to get the amount of ascorbic acid at any time of storage.
KEYWORDS: Orange juice;Ascorbic acid; kinetic; Storage; Model-system.
P
INTRODUCTION
rocessed products ,especially juices have
become more popular because they are
easier to be consumed and are produce with high
nutritional quality.
Orange juice is the most consumed because
of its pleasant taste with high content of vitamin
C.The food and beverages industry is currently
looking for suitable raw materials and packaging
to improve quality and shelf life of
products.Quality and shelf life determination of
an orange juice is strongly based on vitamin C
evolution during storage such as color and
flavor( Lee and Coates,1999; Meydev et al
,1977; Zerdin et al ,2003).Vitamin C is an
essential nutrient for humans and because of its
high antioxidant power it provides protection
against the presence of free radicals participating
in the prevention of many disease.(Tannenbaum
et al ,1985).Orange juice is packed in a wide
variety of materials including metal
cans,paperboard cartons,plastic containers and
glass bottles.When packaging materials do not
provide an adequate barrier to light and
oxygen,the juice , s quality can be affected.The
most common problems involve browning of the
juice is loss in ascorbic acid and changes in the
flavor of the juice.Manufacturers have found that
using different packaging may increase
sales.The factors that affecting vitamin C loss in
packed orange juice are temperature,dissolved
oxygen and oxygen barrier provided by the
container material be considered(Tannenbaum et
al.,1985)Arecent trend is to employ clear
containers in order to attract consumers with the
fresh,bright color of citrus juices.Glass has been
used for this purpose,however,this material is
expensive,heavy,and prone to breakage.An
alternative is to utilize clear plastic(Kabasakalis
et al,2000).Solomon et al(1995) reported that
light no effect on ascorbic acid content and an
insignificant effect on browning of orange
juices stored for 52 days at 8°C.The choice
of the packaging material for fruit juices
is a crucial point regarding shelf life and
much researches has been done on this
subject(Askar,1999;Ebbesen,1998;Siegmud et al
,2004;Zerdin et al,2003).For orange juice plasic
bottle is being actually used in limited
research(Muratore et al,2005).Traditional
methods were used for juice packaging aim to
reduce the exposure of the juice to oxygen
through the use of high barrier materials such
glass or foil laminates in brickpacks ,with or
without nitrogen flushing(Zerdin et
al.2003).Kennedy et al(1992)reported that,when
orange juice was stored for five months at
22°C.They found that greater amounts of oxygen
in the juice led to increased browning.Sattar et
al(1989)reported that ascorbic acid losses were
60.6%,54.6%,51.0%,and 45.5% in clear
glass,Tetrapak laminated paper,and amber glass
respectively,when the containers of orange juice
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