The potential use of phosphatase activity for improving the emulsifying properties in a cheese feed intended for cheese powder production without emulsifying salts.
- Authors
- Mena, Pamela
- Format
- MasterThesis
- Status
- publishedVersion
- Description
The cheese powder is relatively a new product and its production has been increasing over the time; however, there is great demand on reducing the salt content of this product due to health problems. The emulsyfing salts are crucial for its manufacture since it provides a stable slurry (equal to processed cheese) which is afterwards spray dried. These components which are categorized as additives high in sodium concentration, help to stabilize the cheese feed by dispersing the protein and emulsifying the fat. These properties are consequence of the ion exchange produced during the manufacture of processed cheese with the aid of temperature and shredding during the cooking stage. The sodium paracaseinate is responsible for forming a new protein network which will provide the characteristic texture of processed cheese after cooling it down. The objective of this research is to determine if the addition of pure enzyme is feasible to replace the emulsifying salts in the process of cheese powder, thus giving the same stability as using these additives. The dephosphorylation of casein produced by an hydrolysis process performed by the phosphatase might be beneficial for melting the cheese and improving the emulsification properties. Two different enzymes were incubated in the cheese feed, a control for each of them was made, as well as a control with emulsifying salts that would resembled a typical stable cheese feed. The parameters analyzed were heological properties by rotational rheometer, determinating flow behavior, thixotropy and viscosity; emulsion stability by centrifugation, analyzing the phase separation, and also visual parameters detecting homogeneity, stability, fluidity visually by human eye; moreover, the color and shininess were controlled, and additionally the formation of lumps. Another extra analysis was performed in order to check the incubation of the enzyme; phosphatase activity was performed by spectrophotometry. This method also helped to determine the correlation between the amount of pure enzyme and the phosphatase activity found in the different cheese feeds with and without addition or phosphatase. As a final step, potential cheeses for producing a stable slurry were analyzed to stablish their phosphatase activity, that could be native or microbial. This analysis can be useful afterwards to create a formulation with optimal cheeses that might provide more stability to the emulsion regarding the dephosphorylation of casein (future research). The results showed that acid phosphatase provided higher viscosities closer to the ones obtained with ES, as well as regarding emulsion stability, this enzyme helped to prevent more phase separation specifically the initial cream layer and the final serum phase (p<0.05). The alkaline phosphatase did not present a clear tendency (p>0.05) and in general was less stable than the cheese feed with acid phosphatase. The homogeneity and fluidity visually analyzed correlated with the viscosity and emulsion stability results. Also, the color and shininess were not affected by the addition of this enzyme that is a beneficial aspect; for instance, in the case of acid phosphatase, it provided the same appearance as applying emulsifying salts in the process. Finally, in the analysis of potential cheeses for creating a stable emulsion formulation showed that camembert presented the highest concentration of acid and alkaline phosphatase taking in account that this cheese was made with raw milk. Also, blue cheese had a high acid phosphatase activity, but not the same alkaline proportion. Consequently, these two cheeses would be optimal to include in a new formulation, in future studies, which can be providing a stable cheese feed.
- Publication Year
- 2015
- Language
- eng
- Topic
- PROCESAMIENTO DE ALIMENTOS
BIOTECNOLOG?A
TECNOLOG?A QU?MICA
QUESOS
- Repository
- Repositorio SENESCYT
- Rights
- openAccess
- License