2.7.4 Effect of salting on composing of egg
The difference in osmotic force per unit area between egg white and egg yolk together with pickling medium is due to moisture decrease during salting. Familiarly, wet content migrates from egg yolk to egg white, so to the environment through the egg shell. During brining in concentrated saline solution, NaCl is bit by bit diffuses into the egg white and egg yolk through the outer surface of pores and the membrane of the shell. The shell eggs become dehydrated during brining. This is because the lessening in wet content is greater than the addition in NaCl. The different pore size and construction of the shell impact the rate of salt diffusion and therefore impact the wet decrease. Chi and Tseng ( 1998 ) reported that more decrease in wet content of egg yolk occurred for duck yolk than for poulet yolk. In general, the wet in the yolk increased in the last phase of the brining ( Kaewmanee, 2010 ) . This phenomenon of yolk hydration is due to the weaker yolk membrane in the ulterior phase ( Kaewnaee, 2010 ) . The wet content in duck and poulet egg white decreased at similar rate ( Chi Tseng, 1998 ) .
Lai et al. , ( 1997 ) ( TAKE FROM KAEWNAEE BOOK 2010 ) reported that the alteration in entire lipoid of the egg during salting is related to NaCl soaking up and wet addition or loss. The entire lipid content increased from 34 to 64 % in signifier of a wet footing, in the first 6 hebdomads and so reduced to 31 % . However, the entire lipid content decreased from 64 to 53 % in signifier of a dry footing ( Kaewnaee, 2010 ) . The entire lipoid, base on salt free solids was unchanged. This show that entire lipid content was non changed during brining ( Lai et. , 1999 ) . For free lipid content, it increased in the first 6 hebdomads and decreased subsequently ( Lai et. , al 1999 ) . Most lipoids in the egg yolk exist in low denseness lipoprotein ( LDL ) ( Gilbert 1971 ) . Schulte et. , Al ( 1968 ) pointed out the remotion of wet from egg yolk increased due to the structural alteration of LDL. Thus, the desiccation during salting likely enhanced oil exudate.
2.7.3Effect salting on hardening of egg yolk
The egg yolk is bit by bit becomes solidified and hardened during salting ( Chi and Tseng, 1998 ) . The salt-cured egg yolk turns to be elastic gel. Several types of atoms like domains, granules or LDL in egg yolk are suspended in a protein solution or plasma ( Kaewmanee, 2010 ) . Both fractions of liquid eggs have the capacity to organize gels ( Woodward and Cotterill, 1987 ) . The permeableness of salt through egg shell is studied antecedently by Chi and Tseng ( 1998 ) . Salt migrated from surfacing paste or saturated seawater into egg white so to egg yolk. The desiccation of egg yolk and diffusion of salt into egg white and egg yolk occurred at the same time during salting. Salt content in egg yolk besides increased with the salting clip at the same period. Both effects can do the hardening of egg yolk. Lai et. , Al ( 1999 ) studied and explained the relationships between salted egg yolk formation and NaCl incursion grade. During salting procedure, granulation and gelation of yolk appeared in the different phases. Therefore, the formation of salt-cured egg yolk was governed by the grade of NaCl incursion ( Lai et al. , 1999 ) .
The egg yolk produces break of granules as salt is adding and this supplying extra protein to better the functional belongingss of yolk incorporating nutrient systems ( Kaewmanee, 2010 ) . Shenstone ( 1968 ) reported that the ability of electrolytes to impact the conformation of ball-shaped protein is depend on the concentration of salt or ionic strength of salt. The influences that salt exerts on protein construction is governed by electrostatics interactions at low ionic strength. However, the ability of salts to stabilise protein construction is related to the discriminatory hydration of the protein molecules as a consequence of salt induced change of H2O in the locality of the protein at higher ionic strength ( Kaewmanee, 2010 ) . Protein-protein interactions favored over protein solvent interactions at high salt content due to miss of H2O molecules, which may take to collection of protein molecules.
2.7.4Effect of salting on colour of egg
During salting, the colour of egg yolk became darkened in orange colour ( Chi and Tseng, 1998 ) . The alteration in colour of egg yolk may be due to the desiccation during salting. Yellow colour of yolk comes from lutein and zeaxanthin ( Hintonet. , Al1974 ) and is influenced by concentration of pigment. Man-made oxycaratenoid such as canthaxanthin and citranaxanthin can bring forth a aureate xanthous colour in the duck egg yolk was found by Tai. ,et Al( 1985 ) . The egg yolk became darker xanthous when stored at low wet for a long clip is due to removal of wet ( Lin, 1983 ) . The colour of cooked yolk is xanthous before salting. The cooked yolk bit by bit change into a xanthous brown, dark brown, ruddy orange and light yellow from the outer regon to centre during 24 hebdomads of salting ( Kaewmanee, 2010 ) . Laiet. , Al( 1999 ) pointed out that the alteration on the yolk colour of cooked eggs during salting is related to moisture addition or loss and sum of free lipoid in the yolk.
2.8Sensory quality: Hedonic Ranking Test
Centripetal analysis is a scientific subject used to arouse, step, analyze and interpret reactions to those reactions to those features of nutrients as they are perceived by senses of sight, little, gustatory sensation, touch and hearing. Centripetal analysis is used for development of new merchandises. This is because lone consumers can state whether they like a merchandise or non. In add-on, Larsen ( 1995 ) reported that the aim of the centripetal analysis is besides of import, particularly when it is used for rountie quality control of nutrient merchandises. Affectional trial is normally apply by nutrient industries, chiefly credence trials when they need to optimise market merchandise acceptableness. When hedonistic graduated tables are used with this aim, the penchant of one paradigm in relation to the others samples is inferred from the acceptableness means: merchandises showing agencies significantly greater than the others ( P ? 0.05 ) are considered to be preferred.
Hedonic trial is one of the commonly used methods to measure consumer penchants. It is a type of affectional trial and is of import subjective trial that frequently used in centripetal trial. The word “hedonic” is of Grecian beginning and relates to degree or magnitudes of like or dislike. This evaluation graduated table method is used to mensurate the degree of the penchants or liking of nutrients, or any other merchandise where an affectional tone is necessary. People’s ability to show or pass on their feelings of like and dislike is focus by this hedonistic superior trial. Hedonic ranking trial is popular as it may be used by untrained panellists every bit good as trained panellists. A minimal sum of verbal ability is necessary for dependable consequences ( Mahony, 1986 ) . Tonss can be obtain by change overing the hedonistic evaluations and treated by rank analysis or analysis of discrepancy ( ANOVA ) . Amerine et Al, . ( 1995 ) reported that the hedonistic graduated tables are used with both trained and untrained panellists, and research show that untrained panel give the best consequence.
For hedonistic trial, the rating and appraisal is based on the graduated table but non comparing between the series of samples. The evaluation graduated table that suited in hedonistic graduated table consist five, seven and nine points graduated table, which is each coming their statements or class. The most common hedonistic graduated table is 9 point graduated table. This graduated table has been tool of pick, since 50 old ages ago in both academe and industrial consumer research ( Jones et al. , 1955 ; Peryam & A ; Pilgrim, 1957 ) . However, 7 point graduated table is used during hedonistic trial for this survey. 7 point graduated table is from the truncated of 9 points graduated table. It has been reported that 9 point hedonistic graduated table has possible job associated with class graduated tables: the classs are non needfully every bit spaced, the impersonal ( “neither like nor dislike” ) class makes the graduated table less efficient and consumers tend to avoid the utmost classs ( Lawless & A ; Heyman,1999 ) . Lawlwss and Heyman ( 1999 ) besides reported that the cut downing the graduated table to 7 or even 5 points is sometimes considered since it is felt that consumers will non show utmost reaction.
2.9 Texture Profile Analysis ( TPA )
Texture is basically that affect of physical and chemical belongingss on our senses of sight, hearing and touch and is an of import property in our perceptual experience of nutrient. A texture profile is defined as the organoleptic analysis of the texture composite of a nutrient in footings of its mechanical, geometrical, fat wet features, the grade of each present, and the order in which they appear from first bite through complete chew. ( Margaret, Skinner and Coleman, 1962 ) .
TPA has been widely applied to prove solid or semi-solid nutrient. TPA was developed in the early sixtiess by a group at the General Foods Corporation Technical Center ( Szczesniak & A ; Kleyn, 1963 ) . TPA is used to analyze the mechanical belongingss of nutrients and their relationship to the texture of nutrients. It involves a “two bite” compaction trial which stimulates foremost two chaws on the nutrient and the end product is a curve of force versus clip. From the end product of instrument, one is able to mensurate five primary features ( hardness, coherence, adhesion, snap besides called give and crispness besides called fracturability, and there are besides several derived features. The original TPA was carried out utilizing the Generals Foods ( GF ) Texturometer by Friedmanet Al.( 1963 ) . Bourne ( 1968 ) had developed newer TPA by utilizing the Instron Universal Testing Machine.