The effect of composition of ternary mixtures containing phosphate and citrate emulsifying salts on selected textural properties of spreadable processed cheese

Potassium-based emulsifying salts in processed cheese: A rheological, textural, tribological and thermal approach

The aim of the study was to investigate the impact of potassium-based emulsifying salts (ES; 2% wt/wt concentration) with different phosphate chain lengths [dipotassium hydrogenphosphate (K2HPO4; DKP), tetrapotassium diphosphate (K4P2O7; KTPP), pentapotassium triphosphate (K5P3O10; TKPP)] on the physicochemical, viscoelastic, textural, tribological, thermal, and sensory properties of processed cheese (PC; 40% wt/wt dry matter, 50% wt/wt fat in dry matter) during a 60d storage period (6 ± 2°C). On the whole, the hardness of all PC samples increased with the increasing chain length of ES (DKP < TKPP < KTPP) and the prolonging storage period. Moreover, the hardness results were in accordance with those of the rheological analysis. All PC samples exhibited a more elastic character (G' > G"; tan δ < 1). The type of potassium-based ES affected the binding of water into the structure of the PC. Furthermore, the study confirmed that the manufactured PCs received optimal sensory scores, without any excessive bitterness. It could be concluded that the type of applied ES and storage length affected the functional properties of PC. Finally, the information provided in this study could serve as a tool for the dairy industry to help appropriately select potassium-based ES for PC manufacture with desired properties.

The gelation behavior of thiolated citrus high-methoxyl pectin induced by sodium phosphate dibasic dodecahydrate

The present study found that sodium phosphate dibasic dodecahydrate (Na₂HPO₄) was capable of inducing the gelation of thiolated citrus high-methoxyl pectin (TCHMP). TCHMP was synthesized by amidation of citrus high-methoxyl pectin. The gel formation exhibited an obvious concentration-dependence, including TCHMP and Na₂HPO₄ concentration. For Na₂HPO₄-induced TCHMP gels (TCHMPGs), gel strength and water holding capacity (WHC) increased, while the microcellular network structure was more compact with the increase of TCHMP and Na₂HPO₄ concentration. Dynamic viscoelastic experiment showed when Na₂HPO₄ concentration was more than or equal to 0.5 mol/L, TCHMP sols could be transferred into gels within 30 min. Crystal property was not changed while thermal stability was improved after phase transition. Gelling forces analysis indicated that disulfide bonds were the main interaction forces in TCHMPGs. Consequently, TCHMPGs were covalently crosslinked and exhibited satisfactory gel performance. The results provide a theoretical basis for the formation of gels by Na₂HPO₄ induced TCHMP.

Changes in stability and in vitro digestion of egg-protein stabilized emulsions and β-carotene gels in the presence of sodium tripolyphosphate

BACKGROUND

Egg proteins are effective emulsifiers and gelators in food systems. However, the physicochemical stability and control release properties of egg-protein stabilized emulsions and gels need to be further improved. The potential of sodium tripolyphosphate (St) to improve the functionality of egg proteins was evaluated.

RESULTS

The emulsions with St had smaller particle sizes and higher zeta potential, leading to better physical stability. Furthermore, the oxidation stability increased with increasing St contents, possibly due to its metal chelating capacity and the improved emulsifying activity of whole-egg dispersions. Phosphate had a positive impact on the chemical stability of β-carotene in whole-egg liquids and gels, decreasing the degradation during thermal treatment. The gel made with St was firm and broke down slowly, leading to a low rate of digestion and β-carotene release in simulated gastric fluid.

CONCLUSION

This study shows that St is useful to improve the egg proteins stabilized emulsions and gels, which is applicable in the development of emulsion-based food grade gel products. © 2021 Society of Chemical Industry.

Phosphorylation modification affects the gelation behavior of alkali-induced duck egg white gels

In this study, sodium tripolyphosphate (STP) and tetrasodium pyrophosphate (TSPP) were utilized to modify duck egg white protein (EWP). The phosphorylated EWP was prepared as egg white gel (EWG) by adding sodium hydroxide. The phosphorus content of EWP reached 2.18 mg/g and 2.07 mg/g with the addition of STP and TSPP, respectively, after 2 h phosphorylation. The average particle size, absolute zeta potential value, and surface hydrophobicity of EWP increased significantly during phosphorylation. FTIR results indicate that phosphorylation reduced the random structure and α-helical content while increasing the content of β-sheets and β-turn. The mechanical and rheological properties of EWG decreased obviously after phosphorylation. A three-dimensional porous network microstructure was formed, and the gel with added TSPP had larger pores. Adding STP and TSPP to EWG weakened its salt and solvent sensitivity. The findings provide a direction for the exploration of gel properties after protein modification.

Microflora of processed cheese and the factors affecting it

The basic raw materials for the production of processed cheese are natural cheese which is treated by heat with the addition of emulsifying salts. From a point of view of the melting temperatures used (and the pH-value of the product), the course of processed cheese production can be considered "pasteurisation of cheese." During the melting process, the majority of vegetative forms of microorganisms, including bacteria of the family Enterobacteriaceae, are inactivated. The melting temperatures are not sufficient to kill the endospores, which survive the process but are often weakened. From a microbiological point of view, the biggest contamination problem of processed cheese is caused by gram-positive spore-forming rod-shaped bacteria of the genera Bacillus, Geobacillus, and Clostridium. Other factors affecting the shelf-life and quality of processed cheese are mainly the microbiological quality of the raw materials used, strict hygienic conditions during the manufacturing process as well as the type of packaging materials and storage conditions. The quality of processed cheese is not only dependent on the ingredients used but also on other parameters such as the value of water activity of the processed cheese, its pH-value, the presence of salts and emulsifying salts and the amount of fat in the product.

The quality of processed cheeses and cheese analogues the same brand domestic and foreign production

Processed cheeses belong to Slovakia favorite dairy products. Processed cheeses are made from natural cheeses. In recent years the trend is to replace natural cheeses with other raw materials of non-dairy nature. The composition of the processed cheese analogues is not in many countries defined by legislation. The objective of this study was to determine and compare chemical properties (fat, dry matter, fat in dry matter, NaCl) two samples of processed cheeses (C, D - Veselá krava) and two samples cheese analogues (A, B - Kiri) the same brand domestic and foreign production. The evaluated was taste of processed cheeses and cheese analogues, too. Chemical analysis and sensory analysis were repeated four times. The results of chemical analysis shows that all rated samples processed cheeses made on Slovakia fulfilled demands declared (dry matter and fat in dry matter) as producers provided on the label. The most commonly fluctuate content of NaCl from 1 to 1.24 g.100g-1. The higher coefficient of variation in the determination of NaCl (3.88%) was found in processed cheeses made in France. Processed cheese and cheese analogues made in France had not specified parameters for dry matter and fat in dry matter on the label. For production cheese analogues Kiri made in Slovakia was used different raw material than Kiri made in France. The taste of products was determined by descriptors - salty, slightly sweet, milky, buttery-creamy, fatty, sour, bitter, and unknown. The interesting that Kiri made in Slovakia had stronger milky and buttery-creamy taste than cheese analogue Kiri made in France. Significant differences were found in the slighty sweet taste of processed cheeses, the most points won processed cheese Veselá krava made in Slovakia.