M.Sc Thesis

M.Sc StudentDaniel Naama
SubjectTexture Properties of Colloidal Poultry Meat System,
Modified by Vagetable Proteins and Polysaccharides
DepartmentDepartment of Biotechnology and Food Engineering
Supervisors PROFESSOR EMERITUS Chaim Mannheim (Deceased)
MS. Hadassa Zuckerman


In a colloidal meat system, vegetable proteins and polysaccharides are attached to the meat, strengthening the gel matrix, covering the fat globules and contribute to the stabilization of the system. Soy protein has been used on a wide-scale for many years as an additive in processed meat products. However, the use of additional vegetable proteins is not common. The objectives of this study were to evaluate the feasibility of replacing soy protein with lupin protein in poultry sausages, and examine the effect of soy and lupin protein concentrates, in combination with polysaccharides, on texture properties of colloidal poultry systems. Lupin protein was found more soluble in water than the soy protein, possibly due to a higher content of hydrophilic amino acids. The soy protein contains more hydrophobic amino acids, and therefore, apparently, creates better contact with the fat and possesses better emulsification ability. Texture analysis, evaluated by the compression test, in accordance with the TPA method, showed that the soy protein contributed to the hardness of the sausages more than the lupin protein. On the other hand, the hardness tended to decrease with a rise in the xanthan content. Both vegetable proteins strengthened the matrix of the meat protein and improved the water holding capacity. Maximum cohesiveness was observed in the combination of 1.5% lupin protein with 0.2% xanthan, in which there was less damage to the structure of the product during the compression. High elasticity was observed in all the samples. Xanthan gum was found effective in reducing weight losses during cooking. It seems that there is a synergy between lupine protein and xanthan, which contributes to the strength of the structure. In contrast, weakening phenomena of the structure were observed in different combinations of soy protein with xanthan.