Gelation of pH-aggregated whey protein isolate solution induced by heat, protease, calcium salt, and acidulant

被引:112
作者
Ju, ZY [1 ]
Kilara, A [1 ]
机构
[1] Penn State Univ, Dept Food Sci, University Pk, PA 16802 USA
关键词
whey proteins; aggregation; gelation; microstructure; pH;
D O I
10.1021/jf9710185
中图分类号
S [农业科学];
学科分类号
09 ;
摘要
Effects of pH (3.0-7.0) on aggregation of whey protein solution (WPS, 18%) were investigated by examination of turbidity, aggregate size, and microstructure. As expected, maximum turbidity and aggregate sizes occurred at the isoelectric point (pI 5.2) of whey proteins. Lower or higher pH than the pI resulted in a steady decrease of the turbidity and aggregate size. Microstructure analysis revealed that the WPS at pH 5.7 contained loose and irregular aggregates with 200-400 nm sizes. From the pH (5.7)-aggregated WPS, gelation was induced by heating, hydrolyzing with a protease from Bacillus licheniformis (BLP), increasing ionic strength with CaCl2, and quiescently acidifying with glucono-delta-lactone (GDL), respectively. The hardness, color, and microstructure of the gels so formed were determined. Micrographs of BLP- and CaCl2-induced gels-showed aggregates similar in size and shape to the parent aggregates in the WPS. Heat-and GDL-induced gels were structured with enlarged aggregates (500 nn and 1-2 mu m). Separating the processes of formation of aggregates and gels may provide a means to manipulate the protein gel properties.
引用
收藏
页码:1830 / 1835
页数:6
相关论文
共 22 条
[1]   Effect of sodium level on the microstructure and texture of whey protein isolate gels [J].
Barbut, S .
FOOD RESEARCH INTERNATIONAL, 1995, 28 (05) :437-443
[2]   CA2+-INDUCED GELATION OF PRE-HEATED WHEY-PROTEIN ISOLATE [J].
BARBUT, S ;
FOEGEDING, EA .
JOURNAL OF FOOD SCIENCE, 1993, 58 (04) :867-871
[3]  
BOURNE MC, 1978, FOOD TECHNOL-CHICAGO, V32, P62
[4]   ELECTRON-MICROSCOPIC STUDIES OF CASEIN MICELLES AND CURD MICROSTRUCTURE IN COTTAGE CHEESE [J].
GLASER, J ;
CARROAD, PA ;
DUNKLEY, WL .
JOURNAL OF DAIRY SCIENCE, 1980, 63 (01) :37-48
[5]   Enzyme-induced gelation of whey proteins: Effect of protein denaturation [J].
Ju, ZY ;
Otte, J ;
Zakora, M ;
Qvist, KB .
INTERNATIONAL DAIRY JOURNAL, 1997, 7 (01) :71-78
[6]  
JU ZY, 1998, IN PRESS J DAIRY SCI
[7]   PREPARATION AND PROPERTIES OF ACID-INDUCED GEL OF WHEY-PROTEIN [J].
KAWAMURA, F ;
MAYUZUMI, A ;
NAKAMURA, M ;
KOIZUMI, S ;
KIMURA, T ;
NISHIYA, T .
JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY-NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 1993, 40 (11) :776-782
[8]   FINE-STRANDED AND PARTICULATE GELS OF BETA-LACTOGLOBULIN AND WHEY-PROTEIN AT VARYING PH [J].
LANGTON, M ;
HERMANSSON, AM .
FOOD HYDROCOLLOIDS, 1992, 5 (06) :523-539
[9]  
MacLeod A, 1995, MILCHWISSENSCHAFT, V50, P666
[10]  
MORR CV, 1990, FOOD TECHNOL-CHICAGO, V44, P100