Physicochemical and functional properites of enzyme modified soy proteins for cheese analogs /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1988.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Ardex F and Supro 710 soy protein isolates were modified by alcalase, α-chymotrypsin, trypsin, liquozyme, and rennet to improve their performance in cheese analog products. Effects of enzyme types and hydrolysis times on molecular and functional properties of these soy protein isolates were investigated. Textural properties and spreadabilities of cheese analogs were evaluated using an Instron Universal Testing Machine and an oven-heating method, respectively. Sodium Dodecyl Sulfate (SDS) gel electrophoretic patterns of Ardex F showed that alcalase, a-chymotrypsin, and trypsin hydrolyzed 7S globulin subunits, the dimer of basic subunit of 11S globulin, and hemagglutinin during an initial 5 min incubation. Alcalase markedly decreased band intensities of acidic and basic subunits of 11S globulin at all incubation times. At 30 min hydrolysis, trypsin removed the acidic subunit band and slightly decreased band intensity of the basic subunit of 11S globulin; a - chymotrypsin slightly decreased band intensity of the acidic subunit of 11S globulin. Supro 710 controls showed much higher values in degree of hydrolysis (DH) and selected functional properties than Ardex F controls. At pH 4.5, solubilities of both Ardex F and Supro 710 hydrolysates were highly correlated to their DH, but the correlation was low at pH 7.0. Rennet-modified Ardex F and Supro 710 were highly soluble at pH 7.0. Solubility behavior of Ardex F hydrolysates at pH 4.5, as affected by hydrolysis times, correlated well with corresponding SDS gel patterns. Trypsin was most effective in increasing DH, solubility and emulsifying capacity of both Ardex F and Supro 710; rennet was the least effective. However, Trypsin-modified Ardex F and Supro 710 showed the lowest heat coagulabilities. α-Chymotrypsin increased DH, solubility and emulsifying capacity of Ardex F less effectively than alcalase, but as effective as alcalase on Supro 710. Unlike Ardex F, alcalase greatly decreased the emulsifying capacity of Supro 710. Alcalase was most effective in decreasing hardness and fracturabilities and increasing springiness and spreadabilities of Ardex F cheese analogs during the initial 5 min incubation. However, at 30 min, α-chymotrypsin was as effective as alcalase... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Food Science and Technology." |
| Physical Description: | xv, 126 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 117-125). |