อนนต์ เลาหรัตนาหิรัญ. Novel Approach in Ameliorating Saltiness of Salted Yolk Cured Using Separated Yolk Brining Process. Master's Degree(Food Engineering). King Mongkut's University of Technology Thonburi. : King Mongkut's University of Technology Thonburi, 2005.
Novel Approach in Ameliorating Saltiness of Salted Yolk Cured Using Separated Yolk Brining Process
Abstract:
This research aimed to explore an alternative means to further reduce the saltiness of salted yolk produced from the separated
yolk brining (SYB) process as described in Thailands petty patent number 1813. The roles of monovalent and divalent salts
(i.e., sodium chloride, potassium chloride and calcium lactate) in improving the physiochemical and sensory properties of brined
yolk using the SYB process were also investigated. More insightful understanding of the SYB process was explored to provide
a useful foundation to realize the SYB process in a commercial-scale production. Duck yolks were separated and brined in 35
percent (w/v) mixed salt solutions containing NaCl and KCl at various concentrations (i.e., 100 percent NaCl, 100 percent KCl,
70 percent NaCl:30 percent KCl and 50 percent NaCl:50 percent KCl) and 5 percent (w/v) calcium lactate. Sucrose at different
concentration levels (i.e., 50, 60 and 70 percent) was also utilized. This research successfully demonstrated the most effective SYB
conditions to produce sated yolks having most of the desirable attributes similar to commercial salted yolks including Na+ content,
moisture content, hardness, saltiness, bitterness, oil exudation, appearance and general acceptability. Sucrose played a significant role
in improving the quality of salted yolk obtained from the SYB process; Sucrose helped to reduce the salt diffusion into the yolk matrix
and dramatically improved the external appearance of the yolk, as characterized by the glossy surface and rounded shape. Microscopic
and macroscopic models delineated the development of brined yolk during the brining process were also proposed. These models helped
to shed light on the inner working mechanisms of the SYB process. Mathematical models based on the Ficks 2nd law, assuming spherical
coordinates, was able to represent both salt and moisture diffusions adequately. The diffusion experiments indicated that effective sodium
and potassium ion diffusivities were 4.77?10-9 and 2.11?10-9 m2/s whereas the effective moisture diffusivities were 3.36?10-9 and
4.40?10-9 m2/s, respectively. The use of monovalent salt (i.e., potassium chloride) and divalent salt (i.e., calcium lactate) to suppress
sodium chloride diffusion was valid; however, these applications were not able to subdue the high level of saltiness in the salted yolks
without adding sucrose. The most suitable levels of brining solution and brining time were 50 percent NaCl:50 percent KCl at 70 percent
(w/v) and 5 hours incubation. These conditions provided similar overall characteristics of salted yolk compared with those of commercial
product based on sensory and physicochemical evaluations.