ABSTRACT

In this study, the use of calcium carbide in the ripening of Citrus sinensis was investigated. The experiment ran for a period of seven (7) days, and three concentrations (1.0g, 2.5g and 5.0g) of calcium carbide were used in two forms (wet and dry), making six treatments (labeled 1.0D, 2.5D, 5.0D, 1.0W, 2,5W and 5.0W according to the concentration and form of treatment) along with a control, labeled CTR, which was used to determine the differences between treated and untreated oranges. One of the aims of this study was to investigate safety issues associated with calcium carbide ripening with regards to accumulation of arsenic impurities in the juice of the oranges. This study also sought to compare the ripening progress of calcium carbide treated oranges with oranges that were allowed to ripen naturally after harvest. The significant differences in sugar levels was also determined, and the oranges, both the control and the treated oranges, showed no significant differences hence, it was deduced that calcium carbide treatment does not increase sugar concentration in oranges. Other results showed significant accumulation of arsenic in the peels and pulp of the oranges, with a notable concentration of 2.15 mg/L of arsenic in the juice of oranges treated with 5.0g of dry calcium carbide. This concentration especially has a detrimental effect on human health. The ripening progress was determined by feel and peel colour change, and the control showed no ripening after seven days. However, treated oranges showed colour change at day 2 even though softeness wasn't felt till day 4 of the experiment. Consuming calcium carbide ripened fruits can be lethal, as they contain accumulated impurities that are hazardous to human health. These fruits look unnaturally ripe, taste bland and consuming them can lead to several health issues from a simple stomach upset to death.