본 연구에서는 시판되고 있는 수입 및 국산 유청분말 제품의 이화학적 및 기능적 특성들을 파악하기 위하여 분석 및 측정을 하였다. pH는 수입한 유청분말의 경우에 $5.85{sim}6.33$이었으며 국산제품의 경우에 $5.70{sim}6.43$이었다. 적정산도는 수입 유청분말이 $0.11{sim}0.18%$이었고 국산품이 $0.10{sim}0.24%$이었다. 제품의 수분, 조회분, 조단백질, 조지방, 조유당함량은 수입품의 경우에 각각 $1.31{sim}2.10%,;7.37{sim}7.49%,;11.54{sim}12.14%,;0.82{sim}1.40%$, 그리고 $64.63{sim}72.66%$이었으며 국산품의 경우에 각각 $2.11{sim}2.81%,;5.39{sim}8.03%,;10.41{sim}20.03%,;1.88{sim}2.54%$, 그리고 $54.32{sim}68.42%$로 나타났다. 활성 SH그룹의 함량은 수입한 유청분말의 경우에 $0.36{sim}0.82{mu}M/g$, 그리고 국산제품에서는$0.29{sim}4.83{mu}M/g$으로 측정되었다. 유청단백질의 용해성은 수입품에서는 $54.50{sim}82.26%$, 그리고 국산품에서는 $26.93{sim}68.44%$이었다. 유화능력과 유화안정성은 수입품의 경우 각각 $5.83{sim}12.53cm^{2}/g$와 $10.24{sim}12.45%$이었고 국산품의 경우 각각 $6.19{sim}11.28cm^{2}/g$와 $7.28{sim}9.93%$이었다. 거품능력과 거품안정성은 각각 수입품이 $4.34{sim}5.54%$와 $0.49{sim}0.66%$이었고 국산품이 각각 $2.56{sim}4.24%$와 $0.15{sim}0.35%$이었다.
In order to understand some physicochemical and functional properties of whey powders, imported and domestic products were analyzed. The pH values of imported whey powder solution were $5.85{sim}6.33$, while those of domestic $5.70{sim}6.43$. The titratable acidity values of imported whey powders were $0.11{sim}0.18%$, while those of domestic products $0.10{sim}0.24%$. The contents of moisture, crude ash, protein, lipid and lactose of the imported whey powder were $1.31{sim}2.10%,;7.37{sim}7.49%,;11.54{sim}12.14%,;0.82{sim}1.40%;and;64.43{sim}72.66%$, respectively, while those of domestic products $2.11{sim}2.81%,;5.39{sim}8.03%,;10.41{sim}20.03%,;1.88{sim}2.54%;and;54.32{sim}68.42%$, respectively. The active SH group contents of imported whey powders were $0.36{sim}0.82{mu}M/g$, while those of domestic products ranged $0.29{sim}4.83{mu}M/g$. The protein solubility of imported whey powders were $54.50{sim}82.26%$, while that of domestic products $26.93{sim}68.44%$. The emulsifying capacity and the emulsion stability of imported whey powders were $5.83{sim}12.53cm^{2}/g$ and $10.24{sim}12.45%$, respectively, while those of domestic products $6.19{sim}11.28cm^{2}/g$ and $7.28{sim}9.93%$, respectively. The foam overrun and stability of imported whey powders were $4.34{sim}5.54%$ and $0.49{sim}0.66%$, respectively, while those of domestic products $2.56{sim}4.24%$ and $0.15{sim}0.35%$, respectively.
