Effect of calcium chloride extracted from eggshell in maintaining quality of selected fresh-cut fruits

Abstract

Purpose A study was conducted to extract calcium chloride from eggshell and also to check the effect of commercially available and extracted calcium chloride on quality characteristics of fresh-cut fruits. Methods Eggshells were mixed with a hydrochloric acid solution and stirred occasionally until no gas bubbles were observed (3 h). The mixture was centrifuged at 3500 rpm for 10 min at 4 °C, the supernatant was separated and heated to 110-115 °C until dried, this yielded calcium chloride crystals or eggshell calcium chloride. The fresh-cut fruit cubes were separately dipped in a solution of 2% calcium chloride extracted from egg shell and 2% commercially available for 5 min. The cubes are packed in polypropylene plastic bags and stored at 5 °C. Analyses were done at 5-day intervals for a time period of 25 days. The microbial count, physical (firmness, weight loss and color), chemical (pH, titratable acidity, total soluble solids, DPPH, reducing sugar, total phenolic content, and ascorbic acid content), and sensory analysis were determined at regular interval throughout the storage period. Results Calcium chloride extracted from egg shell was capable to maintain shelf-life for 15 days, whereas commercial calcium chloride was able to maintain shelf-life for 20 days. This shows calcium treated fresh-cut fruits have an improved and enhanced shelf-life than control (non-treated samples). Conclusions The study proved that dipping fresh cut fruits in CaCl 2 solution (extracted from eggshell and commercially available) extend its shelf-life for 15 days.

Composite Films of Thermoplastic Starch and CaCl2 Extracted from Eggshells for Extending Food Shelf-Life

“…The incorporation of CaCl2 resulted in less of a decrease in the pH value. These results are aligned with the findings from Thakur's group, which investigated the effects of CaCl2 solution on fresh-cut fruits, and reported that the fruits immersed in CaCl2 solution exhibited higher pH value compared to the non-treated fruits [8]. The explanation…”

“…The incorporation of CaCl 2 resulted in less of a decrease in the pH value. These results are aligned with the findings from Thakur's group, which investigated the effects of CaCl 2 solution on fresh-cut fruits, and reported that the fruits immersed in CaCl 2 solution exhibited higher pH value compared to the non-treated fruits [8]. The explanation could be that the reduction of pH value is related to the organic acid generated by microorganisms, and the embedded CaCl 2 inhibited the growth of microorganisms, thus resulting in a higher pH value.…”

“…However, a study reported that papaya, muskmelon and guava samples immersed in CaCl 2 solution exhibited less weight loss than the samples not treated with CaCl 2 solution. One reason for this could be that the calcium strengthened the cell wall and preserved the structure and integrity of the cell membranes, thus resulting in less weight loss [8]. In this study, instead of being immersed in liquid, all the samples were placed on the top of the polymer films, dehydration occurred and the incorporated CaCl 2 increased the water loss, which was supported by a study on the effect of calcium on pineapple dehydration kinetics [40].…”

“…Many methods have been studied in an attempt to extend the postharvest life of fresh-cut fruits. To this end, researchers have been employing treatments with ozone [2], peroxyacetic acid [3], chlorine dioxide [4], hydrogen peroxide [5], organic acid [6], oxalic acid [7], calcium-based solutions [8], antioxidant and antimicrobial coating [9,10], irradiation [11], cold plasma treatment [12], pulsed light [13], ultrasound [14], modified atmosphere packaging [15], active and intelligent packaging [16], and nanocomposite packaging [17].…”

“…However, eggshells are a valuable source of biomaterials rich in calcium salt, which can be recovered from waste and used to stabilize the membrane and strengthen the vegetal cell wall against fungal attacks. The extraction of calcium chloride from eggshells has been reported to be used by dip coating on fruits [8]. The spraying of calcium solutions has also proven to be one of the most effective way to apply calcium to fresh fruits to prevent losses [22].…”