Journal of Basic and Applied Sciences  -   Volume 8 Number 2


Effect of Packing System, Calcium Chloride and Chlorine on the Storage Life of Strawberry Fruits (Fragaria ananassa cv. Kordistan)

Fatemeh Mozhdehi, Vahid Abdossi and Sepideh Kalatejari


http://dx.doi.org/10.6000/1927-5129.2012.08.02.24


Abstract: Effect of packing system, calcium chlorite and chlorine was evaluated on storage life of strawberry fruits. Fruits were treated with commercial grade of chlorine (calcium hypochlorite at 0, 25, 50 and 100 ppm and sodium hypochlorite at 0, 25, 50 and 100 ppm with distilled water) for one minute and then treated with different grades of calcium chlorite 0, 0.5, 1 and 1.5 percentage for five minutes, then were divided to two groups; packed and non packed with plastic cover. Then fruits were evaluated for changes in quantity parameters; pH, TA (Titratable acidity), TSS (Total soluble solids), Dry and fresh weight ratio, water content, Anthocyanin, Ascorbic acid, Ca2+, Sugar and pectin. The results showed that the packed fruits treated with calcium chloride (at 0.5 and 1 percentage) and chlorine (at 50 ppm) remained better when compared with non packed fruits. It was found that packing treatment had not a significant effect on pH. It can also deduce that packed treated fruits showed a lower TA, Anthocyanin, calcium, sugar and pectin while TSS, fresh to dry weight ratio, water content and ascorbic acid was higher in packed treated fruits.


Keywords: Strawberry, storage life, packing, post harvest, calcium chlorite, chlorine

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Chemical Properties of Carburized Mild Steel
A. Oyetunji*,1 and S.O. Adeosun*,2
1Dept of Metallurgical and Materials Engineering The Federal University of Technology, Akure Ondo State
Nigeria
2Dept of Metallurgical and Materials Engineering University of Lagos, Akoka Lagos Nigeria
Abstract: This work evaluates the suitability of using palm kernel shell, animal bone (mammalian bones from cattle) and
sea shell (oyster shell) materials as carburizers for case hardening of 0.078%C mild steel. The mild steel sample used in
this study sourced from universal steel company, Ikeja Lagos Nigeria was cut into suitable sizes using hacksaw machine
for tensile and hardness tests. The carburizing media used were milled into fine powder while Barium trioxo (iv)
carbonate (VI) (BaCO3) was used as an energizer in the carburizing process.
Three rectangular stainless steel plate boxes were fabricated to accommodate each of the steel samples and carburized.
A calculated amount of each carburizer was weighed into each of the stainless steel boxes and 20 wt % of BaC03 was
mixed with each of them. Mild steel samples were covered completely in each of the boxes with the mixture of the
carburizer and energizer placed in the furnace chamber. The carburizing temperatures varied between 700 - 1100oC
while the holding time varied between 1-5 hrs. The boxes and its contents were allowed to cool down to room
temperature in the furnace after carburization.
All samples were heated to 850oC after been soaked for 30 minutes at this temperature and oil quenched. This was to
increase the hardness of the case. Fifteen (15) of these samples were further tempered at 350oC for 2hrs to relieve the
stress built up during quenching. Hardness test, tensile strength tests and chemical analysis were carried out on the
samples. It was observed that the hardness values of the untempered samples are superior to the tempered ones at
carburizing temperatures of 7000C, 8000C and 9000C. On the other hand, the tensile strengths of the tempered samples
are higher relative to the untempered samples at carburizing temperatures of 7000C, 10000C and 11000C. The results of
the carbon analysis show that palm kernel shell and animal bone are potentially suitable to be used as a carburizing
media than the sea shell at high temperatures (above 10000C) with holding time above 1 hr.
Keywords: Carburizers, hardness, tensile, carburizing time and temperature, pack carburizing, quenching and
tempering properties.
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