• 한국수산과학회지
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• 제48권2호
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• pp.168-177
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• 2015

Shell waste from the butter clam Saxidomus purpuratus and littleneck clam Ruditapes philippinarum is a large by-product of shellfish aquaculture, and it is desirable to convert it into value-added products for industrial applications. In this study, calcium carbonate (CaC) polymorphs from butter clam (BCSP) and littleneck clam (LCSP) shell powders and commercial CaC were characterized using Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results revealed that the optimal calcination conditions to eliminate organic substances and improve solubility for both BCSP and LCSP were $800^{\circ}C$ for 8 h in an electrical furnace. Calcination improved the white index of the butter clam (BCCP) and littleneck clam (LCCP) calcined powder compared with shell powders. The calcium content in BCCP (51.1%) was higher than that of LCCP (44.9%) or commercial calcium oxide (CaO, 44.7%). The XRD patterns of BCCP and LCCP were similar to that of CaO. Cubic-like crystals of CaC and irregular crystals of BCCP and LCCP were observed by SEM. The FT-IR and XRD analyses revealed the presence of calcite and aragonite in the BCSP and aragonite in the LCSP, whereas the CaC contained calcite. These results indicate that butter and littleneck clam shells are potential biomass resources for calcium carbonate and calcium oxide.

• 한국수산과학회지
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• 제49권3호
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• pp.301-309
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• 2016

To facilitate the effective use of butter clam shell as a natural calcium resource, we determined the optimal conditions for calcium lactate (BCCL) preparation with high solubility using response surface methodology (RSM). The polynomial models developed by RSM for pH, solubility and yield were highly effective in describing the relationships between factors (P<0.05). Increased molar ratios of calcined powder (BCCP) from butter clam shell led to reduced solubility, yield, color values and overall quality. The critical values of multiple response optimization to independent variables were 1.75 M and 0.94 M for lactic acid and BCCP, respectively. The actual values (pH 7.23, 97.42% for solubility and 423.22% for yield) under optimization conditions were similar to the predicted values. White indices of BCCLs were in the range of 86.70–90.86. Therefore, organic acid treatment improved color value. The buffering capacity of BCCLs was strong, at pH 2.82 to 3.80, upon the addition of less than 2 mL of 1 N HCl. The calcium content and solubility of BCCLs were 6.2–16.7 g/100 g and 93.6-98.5%, respectively. Fourier transform analysis of infrared spectroscopy data identified BCCL as calcium lactate pentahydrate, and the analysis of microstructure by field emission scanning electron microscopy revealed an irregular form.

• 한국식품영양과학회지
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• 제44권6호
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• pp.888-895
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• 2015

패류의 주된 가공부산물인 패각은 주성분이 불용성의 탄산 칼슘으로, 이를 천연 칼슘소재로 활용하기 위해 개조개 패각의 소성분말로부터 가용성 개선 유기산(초산) 처리 칼슘 제조의 최적조건을 구명하고자 하였다. 반응표면분석법을 이용하여 제조한 11개의 시제 초산칼슘의 pH, 용해도 및 수율로부터 구명한 최적 반응조건은 초산 2.70 M 비율에 대하여 개조개 소성분말 1.05 M이었으며, 이의 최적조건을 적용한 개조개 초산칼슘의 실측 pH, 용해도 및 수율은 각각 pH 7.04, 93.0% 및 267.5%로 예측치와 유사한 결과를 얻었다. 시제 초산칼슘의 완충능은 pH 4.88~4.92 범위였으며, 칼슘 함량과 용해도는 20.7~22.8 g/100 g과 97.2~99.6%였다. FT-IR, XRD 분석 및 FESEM을 통한 미세구조는 비정형 결정으로 calcium acetate monohydrate로 확인되었다. 개조개 패각은 칼슘소재뿐만 아니라 가용성을 높인 유기산 칼슘으로 칼슘강화용 식품소재로의 이용 가능성이 높을 것으로 판단되었다.

• 한국수산과학회지
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• 제51권5호
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• pp.556-565
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• 2018

The age and growth of butter clams Saxidomus purpuratus were estimated using transmitted light on the shells of 364 samples from January 2017 to December 2017 in Jinhae Bay. Based on monthly variation in the marginal index (MI) of the shell, it is assumed that rings are formed once a year during the period from July to August in this species. The relationship between shell length (SL; mm) and shell height (SH; mm) was expressed by the equation SH=0.8053SL-2.9636 ($R^2=0.94$) and between SL and shell width (SW; mm) by the equation SW=0.5648SL-3.7105 ($R^2=0.90$). The relationship between SL and total weight (TW; g) was expressed by the following equation: $TW=0.00009SL^{3.2141}$ ($R^2=0.96$). von Bertalanffy's growth parameters were estimated using the regression wizard in the SigmaPlot computer program (Systat Software, Inc., v. 10.0). The maximum shell length ($SL_{\infty}$) was 126.16 mm, growth rate was 0.2030/year, theoretical age at shell length 0 ($t_0$) was -0.52 years, and asymptotic total weight ($TW_{\infty}$) was 509.17 g. Growth curves for SL and TW fitted to the von Bertalanffy's equation were expressed as follows: $SL_t=126.16(1-e^{-0.2030(t+0.52)})$, $TW_t=509.17(1-e^{-0.2030(t+0.52)})^{3.2141}$.