Sindayikengera Séverin, Xia Wen-shui
Key Laboratory of Food Science and Safety, Ministry of Education, Southern Yangtze University, Wuxi 214036, China.
J Zhejiang Univ Sci B. 2006 Feb;7(2):90-8. doi: 10.1631/jzus.2006.B0090.
Whey protein concentrate (WPC 80) and sodium caseinate were hydrolyzed by Protamex to 5%, 10%, 15%, and 20% degree of hydrolysis (DH). WPC 80, sodium caseinate and their hydrolysates were then analyzed, compared and evaluated for their nutritional qualities. Their chemical composition, protein solubility, amino acid composition, essential amino acid index (EAA index), biological value (BV), nutritional index (NI), chemical score, enzymic protein efficiency ratio (E-PER) and in vitro protein digestibility (IVPD) were determined. The results indicated that the enzymatic hydrolysis of WPC 80 and sodium caseinate by Protamex improved the solubility and IVPD of their hydrolysates. WPC 80, sodium caseinate and their hydrolysates were high-quality proteins and had a surplus of essential amino acids compared with the FAO/WHO/UNU (1985) reference standard. The nutritive value of WPC 80 and its hydrolysates was superior to that of sodium caseinate and its hydrolysates as indicated by some nutritional parameters such as the amino acid composition, chemical score, EAA index and predicted BV. However, the E-PER was lower for the WPC hydrolysates as compared to unhydrolyzed WPC 80 but sodium caseinate and its hydrolysates did not differ significantly. The nutritional qualities of WPC 80, sodium caseinate and their hydrolysates were good and make them appropriate for food formulations or as nutritional supplements.
乳清蛋白浓缩物（WPC 80）和酪蛋白酸钠用Protamex水解至水解度（DH）为5%、10%、15%和20%。然后对WPC 80、酪蛋白酸钠及其水解产物进行分析、比较和营养品质评估。测定了它们的化学组成、蛋白质溶解度、氨基酸组成、必需氨基酸指数（EAA指数）、生物价（BV）、营养指数（NI）、化学评分、酶促蛋白质效率比（E-PER）和体外蛋白质消化率（IVPD）。结果表明，Protamex对WPC 80和酪蛋白酸钠的酶促水解提高了其水解产物的溶解度和IVPD。与粮农组织/世界卫生组织/联合国大学（1985年）参考标准相比，WPC 80、酪蛋白酸钠及其水解产物都是优质蛋白质，且必需氨基酸有盈余。从氨基酸组成、化学评分、EAA指数和预测BV等一些营养参数来看，WPC 80及其水解产物的营养价值优于酪蛋白酸钠及其水解产物。然而，与未水解的WPC 80相比，WPC水解产物的E-PER较低，但酪蛋白酸钠及其水解产物没有显著差异。WPC 80、酪蛋白酸钠及其水解产物的营养品质良好，使其适合用于食品配方或作为营养补充剂。
