Preparation and Partial Characterization of Eggshell Calcium Chloride

Figures & data

Figure 1 Extraction process for eggshell CaCl₂.

Figure 2 X-ray diffraction patterns of eggshell calcium chloride (top figure) and commercial calcium chloride (bottom figure). For comparison, the X-ray diffraction data of CaCl₂.2H₂O (#70-0385), CaCl₂.4H₂O (#25-1035) and CaSO₄ (#73-1942) are shown below the corresponding diffractogram.

Table 1 % Yield of eggshell CaCl₂ from different treatment

		Ratio of eggshell to HCl			CaCl2.2H2O ^1 (%)
Treatment	Con^n of HCl(%)	(W/V - Sol^n)	(w/w)	Yield ^1 (%)
1	3	1 : 5	1 : 0.178	18.78^i	117.49^cd
2	3	1 : 10	1 : 0.357	37.58^f	119.27^b
3	3	1 : 15	1 : 0.535	68.88^d	116.21^de
4	4	1 : 5	1 : 0.238	27.77^h	116.12^e
5	4	1 : 10	1 : 0.476	56.38^e	117.59^c
6	4	1 : 15	1 : 0.714	87.38^b	121.55^a
7	5	1 : 5	1 : 0.298	31.47^g	119.15^b
8	5	1 : 10	1 : 0.595	83.35^c	111.67^f
9	5	1 : 15	1 : 0.893	90.80^a	119.76^b
W/V - Sol^n: wt. of crushed eggshell to volume of HCl - Sol^n; w/w: wt. of crushed eggshell to mass of HCl in acid solution.
^1Different letter superscript in the same column shows significant differences at P < 0.01.

Table 2 Analysis of metal impurities in eggshell CaCl₂ compared with specification stated in Thai Food Act[8]

Impurity	Eggshell CaCl2	Food Act
Magnesium (Mg) and its alkali salts (%)	1.75	not over 1
Arsenic (As) (mg/kg)	0.18	not over 3
Heavy metal (mg/kg) (calculated as Pb)	not over 20	not over 20
Lead (Pb) (mg/kg)	not found	not over 10
Fluoride (mg/kg)	15.9	not over 40

Table 3 Peak force of canned rambutan measured by TA Analyzer

Soaking condition	Peak force ^1 (gm)
Rambutan without soaking in CaCl2	100.65 ± 30.04
Rambutan soaked in commercial CaCl2 sol^n	181.26 ± 41.01
Rambutan soaked in eggshell CaCl2 sol^n	165.56 ± 42.97
^1Means calculated from 7 replicates.

Ministry of Health and Welfare . 1979 . Food Act Bangkok, , Thailand

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