Effects of calcium chloride and
calcium lactate on shelf life extension of sweet orange
a huge kingdom that includes different basic cultivated species,
including Citrus reticulate (tangerine & mandarin), C. sinensis (sweet
orange), citrus lemon (lemon), Citrus paradise (grapefruit) and
Citrus grandis (pummelo). In the year 2009, the worldwide citrus production was
one hundred and twenty two point three (122.3) million on an acreage of nine (09)
million hectares (FAO statistics), which is ranked the highest among the entire
fruit crops. In the year 2009, among the ten point nine (10.9) million tons (of
value $9.3 billion) of the citrus products were traded, sweet orange ratio
was approximately sixty percent (60%) of the citrus production both for processed
juice and fresh fruit consumption (FAO statistics).
is one of the most vital fruit crop cultured in Pakistan. The production of
citrus is about 1982.2 thousand tons per year, cultivated over an area of about
194.5 thousands hectares. In Pakistan mostly it is cultivated in Punjab Khyber
Pukhtunkhwa and Quetta region of Baluchistan. (Agri-statistics of Pakistan,
fruits have a high commercial value in the fruit market. Among them, oranges
can be considered as a good source of bioactive compounds, in which their
consumption would have health benefits for humans. However, high moisture
content and nutrient composition make this fruit more susceptible to fungi
contamination. It should be noted that such products are also susceptible to
softening, of browning, or color change and microbial contamination, too (Dhall
R. K, 2013).
orange is type of the fruit which belongs to citrus sinensis included in family
Rutaceae. The biological name of
sweet orange is citrus sinensis (Agriculture Statistic of Pakistan.2013-3015). It
provides about one hundred and thirty percent (130%) of FDA’s recommend daily
intake of ascorbic acid about sixteen percent (16%) of dietary.
one of type of the sweet oranges is most widely grown in India. Shape of the fruit
is round and a little bit seedy. Skin color of the fruit is yellowish to pale
orange on ripeness. Flesh of the fruit is slightly firm and juicy, even though because
of the very low acidity, it is fairly flavorless (Dharmawan et al 2007).
previous work observation has been made about the useful effects of calcium, it
can be used to reduce respiration rate so the ripening and senescence deferred engaged
shelf life. Calcium plays a key role in stabilizing and giving mechanical hardness
to cell structure stiffening agent of fruit). The use of Calcium has been extensive
in the fruit and vegetables sector for fresh cut and the overall commodities as
the firming agent and the preservative (Chardonnet et al.,
2003). Almost in all pervious works done the amount of calcium salts used lies
in the range of 0.5–3% (Martín-Diana et al. 2007). The bond between pectin
and calcium become stronger by the addition of the calcium salt, because of
which the structure of cell wall become stiff (Akhtaret al., 2010). Cell wall’s cohesion increases due to presence of
calcium ions and therefore decreases the ripening and senescence of the fruits
because of the application of the calcium to the fruit surface. The Storage
life of the fruit is improved to some extent and the softening is delayed when the
fruits are treated using calcium chloride to that of the untreated fruits
(Akhtaret al., 2010).
Calcium treatments, either with
calcium chloride (CaCl2) or calcium lactate, have been shown to be effective at
maintaining firmness during storage in numerous fresh-cut fruit and vegetable studies.
Examples include pear (Rosen and Kader 1989), mango (Chantanawarangoon 2000), lettuce
(Martin-Diana and others 2006), carrot (Rico and others 2007), (Beirao-da-Costa
and others 2008), melon (Silveira and others 2011), and. Despite these
promising studies, application of calcium to fresh-cut mango is not yet used in
commercial practice. Calcium ions passively can diffuse within the cell wall
structure because plant cell wall porosity is approximately
3.5 to 9.2 nm (Read and Bacic 1996), while calcium ions are about 0.1 nm
(Gillard 1969). In fruit preservation practices, when fruit parenchyma cells
are dipped in a calcium salt solution, calcium ions are transported primarily
through the applets, or intercellular spaces, where they are attracted by
negatively charged carboxyl groups in homogalacturonan that constitutes of
pectin in the middle of cell wall and lamella. The harmfully charged lactate
ions or chloride remains unbounded in the solution. (Harker and Ferguson 1988;
Hasegawa 2006). A second, slower procedure for uptake of calcium ions relates
to their attraction to the phospholipids of the plasma membrane (Demarty and
others 1984). Therefore, the firming effect of calcium treatments in initial
stages is accounted for by the cross-linking of calcium ions to the
homogalacturonan in the middle lamella and cell walls, while the subsequent
firming during storage (Mignani and others 1995; Picchioni and others 1996) may
be due to the contact of calcium ions with negatively charged head groups of
plasma membrane phospholipids and proteins. Due to which calcium ions protect
the membrane from lipid degradation by making the plasma membrane stable. This
makes the chances reduced for degradation by lipolytic enzymes. The calcium
bridges which is formed in cell walls have also been reported according to
which it reduces approach to bacterial hydrolyses or fungal that cause decay
(Mignani and others 1995).
chloride and calcium lactate have been used as firming agents in a wide range of fruits. These compounds
function by binding to the negatively charged carboxylic acid groups of
galacturonic acid residues in the pectin chain and forming an egg box gel model
resulting in the strengthening of the cell wall (Grant et al., 1973).
Calcium lactate, calcium chloride, calcium glutamate and calcium phosphate are commonly used for enhancements and prevention
of the firmness of the product. (Manganaris et al.,2005).The further
observation made was that calcium lactate can be substitute of calcium as it is a food additive and it also prevent cut surface from browning and
tissues softening of fresh cut fruits.
1. Effects of calcium lactate and
calcium chloride on physicochemical
properties of sweet orange. 2. To prolong the shelf life of orange
by treating it with different
concentrations of cacl2 and
To study the sensory attributes of control and fruits treated with Calcium
chloride and calcium lactae.
REVIEW OF LITERATURE
(Panita et al. 2014) directed a research in which the influence of calcium
chloride and calcium lactate maintaining the textual and sensory quality of the
cut mangoes. Cubes of mango of 1.5cm were introduced to differ calcium lactate
and calcium chloride application and immersed if for 1, 2, and half and five
minutes . Mango cubes immersed in calcium chloride or calcium lactate for 1-3 minute
successfully developed retention and firmness. Though calcium chloride applied
sample have great result against with the treated samples of calcium lactate.
2015) conducted research and investigated that use of calcium (Ca) prolong the
quality trait of peach fruit. In order to prove the aforesaid statement Cacl2
was used for five minutes at various percentages (1%, 2% and 3%). The results indicated
decreasing trends in the firmness and the ascorbic-acid concentration whereas
an increasing trend in total TSS, weight loss, and decay-index was observed. As
a result storage intervals and various Ca treatments (percentage) had
significant effect on the quality trait of the peach. Furthermore it was made
known that the peach fruits applied with one percent (1%) and two percent (2%)
calcium chloride have slight on quality trait of peach as compared to 3% CaCl2
which were more effective for the said trait.
Irfan et al. (2013) conducted research on the
effect of Ca application on quality trait (to prolong shelf life) of fig fruit.
The results showed that ascorbic acid concentration and color of the fig fruit were
significantly affected by Ca. Uses of CaCl2 limited the development and
growth of fungi and bacteria. Furthermore, the application of CaCl2
increased/enhanced the shelf life of the fig fruit by increasing the time for
Kirmani et al. (2013) conducted an experiment on
role of calcium chloride (CaCl2, gibberellic acid and naphthalene
acetic acid on increasing the shelf life of the plum. Results showed that firmness,
weight and size were significantly decreased by uses of the CaCl2 throughout
the storage. Moreover, during last stage of storage the fruit treated with Cacl2
along with GA3 was considered the most suitable technique for prolonging
the shelf life of the said fruit.
Nazmy et al. (2012) conducted an experiment on
the use of calcium and wrapping film on quality of pomegranates. Pome fruits
were put in various concentrated solution of Cacl2 (0%, 1% or 3%)
either only or along with film wrapped for only 4 minutes. Results showed significant
variation in case of rate of respiration and loss in weight for the said fruit
in all wrapped fruit compared to that of the non-film wrapped, however firmness
of the fruit, sensory quality vitamin C content and thickness of the fruit’s
outer portion (the peel) were retained higher when the pome fruits were treated
with calcium chloride, CaCl2 (2 %) solution in combination with the
films wrapped. No major variation was witnessed for the values of anthocyanin
and TSS contents.
research was conducted (Chafer et al.
2012) on quality trait (the shelf life)
and the fungal deterioration of oranges treated (coated) with Bergamot and chitosan,
Tea Tree Essential oils and Thyme and concluded that by using pure CH films no
anti-fungal activity was observed against p. italicum. theanti the fungal
properties of chitosan composed film were mainly dependent on either the medicinal
(curative) or the treatment was protective discovered in a microbiological examination.
Coating/covering by using the TTO was more effective against any antifungal activity
of p. italicum. The highest antifungal activity was observed for treating the
fruit with TO whereas minimum effectiveness was recorded for the curative coating.
Furthermore post-harvest investigation recommended that coating had no visible
effect on growth of fruits, but they somewhat improve the water vapor barrier
properties, particularly when they comprises important oils C. To decrease/minimize
microorganisms deterioration (especially fungal decay) coating with CH containing
TTO is recommend for orange fruit cultivars. With the caution that it uses do
not cause any injury to said fruits.
et al. (2011) conducted research
experiment on the effect of temperature and storage period on quality character
of the blood orange. Maximum PH and anthocyanin content was found after 90 days
of storage at temperature of 8°C. While decrease in TSS, % acidity, loss in weight
and vitamin c contents was also observed at various storage temperature.
Akhtar et al. (2010) conduct research on the effect calcium (Ca) coating on storage and
quality of the loquat fruit by soaking it in several concentration of calcium
chloride (CaCl2 (one percent, two percent and three percent (1%, 2%
& 3%) for at least two minutes and retained in soft board boxes at 4°C in
cold condition up to 4-5 weeks intervals. Results showed that 1% Cacl2
did not significantly affected the quality parameter of fruit as compared to
control, whereas when the fruit is coated
with two and three percent (2% & 3%)
concentration of calcium chloride lower down the browning index, loss in the weight
and reserved TSS, maximum firmness and ascorbic acid concentration at least four
to five weeks.
Rab et al. (2010) conducted research
on quality of the fruit and senescence related changes in the sweet orange
cultivar blood red uni packed in different covering materials and recommended
that the citrus fruit continue to lower in quality and test during the storage.
At side of the turn down in test the quality among different uni-packing
materials in fruits is longer than rest of the uni-packing material. Quality
and the retaining taste was also accompanied by a lesser amount of weight loss,
retention of the total ascorbic acid solids and the percent acidity which lead
to lower in TSS/Acid ratio. Both cellophane and polyethylene were suggested as
uni-packing material for the sweet orange. The fruit lost its value greatly
after forty five (45) days of storage, cellophane and polyethylene. Uni-packing
can be suggested only as a short span of storage to retain taste along with
chemical quality aspects.
et al. (2008) carried experiment on peach
fruit for its storage by soaking in 2% Cacl2 solution for at least half
hour at 20oC temperature along with
storage length of maximum 2 weeks at 4oC
in boxes packed. The uses of Cacl2 and the polyethylene barrier/boxes
packed showed better improvement in storage. Moreover quality attributes like firmness,
increased in sugar to acid ratio and TSS was significantly maintained by the
uses of Cacl2 salt.
Hagenmaier et al. (2000) during his research assessed
polyethylene -candelilla coating for the “Valencia” orange in comparison to a high-gloss,
wood and shellac resin citrus coating for storage of the ‘Valencia ‘orange at
15 to 25°c. The high flavor score (8.9-10.4) even after 9 to 16 days of storage
at temperature 15 to 25°C were shown by orange coated with wax. In comparison
the high gloss coating results in flavor score as low as 3.7-4.1 after 9 to16 days
at 25°C or16days at 21°C. For fruit with internal 02 B1% flavor was low. The flavor
was reduced on increasing the content of ethanol, which in turn was very much
dependent on the internal carbon dioxide(Co2). Fruits with the wax coating have
lower gloss than the fruits coated with wood and shellac resins, however this
advantage may lost after eight (8) days of storage at 15 to 25°C
III. MATERIALS AND METHODS
Oranges at the optimum stage of
maturity will be taken from Peshawar market, then will be brought to the food
processing lab of “Nuclear Institute for Food and Agriculture” Peshawar, Khyber
Pakhtun Khawa, Pakistan where research work will carried out. Damaged and
disease portion of oranges will be discarded. And for the removing of chemical,
dust, dirt and other materials these oranges will be washed thoroughly with
Plain of study
Fresh sweet orange (control)
Weight loss (%)
Wang et al., (2012) described a method by
which weight loss percentage will be determined.
Total soluble solids (TSS)
TSS of apple juice will be directly
observed by the digital refractometer, the results will be presented as soluble
solids(°Brix) as stated in the AOAC (2012).
Fruit firmness/ Hardness (kg/cm2)
By applying standard method of AOAC
(2012) will be determine the firmness of fruits.
Ascorbic acid (mg/100g)
acid content of the samples will be recorded by Indophenol titrimetric method
as reported by AOAC (2012).
Titratable Acidity (%)
the standard method of the AOAC (2012), the percent acidity will be calculated.
pH of the apple fruit will
be recorded by digital pH meter as described in standard method of AOAC (2012).
Decay index (%)
et al. (2012) narrated a standard
method by which the percentage (%) decay index will be calculated.
treated orange fruit samples will be analyzed organoleptically for flavor,
color, taste and overall characteristics by the panel of judges. Organoleptic
analysis will be evaluated at the preservation for interval of seven (7) days
for total duration of one month. Then it will be evaluated using nine (9)
points of Hedonic scale of Larmond (1977).
data will be recorded for Analysis of Variance by using CRD complete randomized
design with 2 factorials (Steel and Torrie, 1997).