Properties of spreadable processed Mozzarella cheese with divergent compositions of emulsifying salts in relation to the applied cheese storage period

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 Impact of Different Hydrocolloids on the Viscoelastic Properties and Microstructure of Processed Cheese Manufactured without Emulsifying Salts in Relation to Storage Time

The current study was conducted to evaluate the effect of the addition of selected hydrocolloids [agar (AG), κ-carrageenan (KC), or gelatin (PG); as a total replacement for emulsifying salts] on the viscoelastic properties and microstructure of processed cheese (PC) samples during a storage period of 60 days (at 6 ± 2 °C). In general, PC viscoelastic properties and microstructure were affected by the addition of hydrocolloids and the length of storage time. The evaluated PC reported a more elastic behavior (G′ > G″) over the viscous one. The highest values of viscoelastic moduli (G′; G″; G*) were recorded for PC samples manufactured with KC addition, followed by those prepared with AG and PG. The control sample presented values of viscoelastic moduli similar to those of the PG sample. All PC samples tested had fat globule size values lower than 1 μm. Moreover, PC with AG and KG addition presented similar microstructures and sizes of fat globules.

Comprehensive identification of molecular profiles related to sensory and nutritional changes in Mongolian cheese during storage by untargeted metabolomics coupled with quantification of free amino acids

Non-targeted metabolomics was used to study metabolites with low molecular weight which may contribute to quality deterioration of Mongolian cheese during storage. Microbiological analysis, pH, FAAs (free amino acids), volatile compounds, and sensory evaluation of the cheese during storage were also studied. A total of 278 metabolites were identified in Mongolian cheese, of which 51 metabolites were used as differential metabolites, including amino acids, peptides, organic acids, lipids, and carbohydrates. Bitter amino acids, bitter peptide (Phe-Ile), and organic acids (sinapic acid, butyric acid) increased during storage. Metabolic pathway analysis showed that differential metabolites were mainly related to amino acid metabolism, such as β-alanine metabolism and glycine, serine, and threonine metabolism. Moreover, accompanied with the increased contents of short-chain fatty acids, 2-undecanone and ethyl esters, strength of odor and unpleasant smell increased but overall acceptability decreased during Mongolian cheese storage. This research provides suitable strategies for quality control of Mongolian cheese during shelf life.

Improving the texture properties and protein thermal stability of Antarctic krill (Euphausia superba) by L-lysine marination

BACKGROUND

The quality deterioration of Antarctic krill (Euphausia superba) after thermal processing limits its industrial application. This study sought to improve the texture characteristics of Antarctic krill after heat treatment through pre-soaking using l-lysine (Lys) solution and sodium tripolyphosphate (STPP). Moreover, the effects of Lys on heat-treated Antarctic krill were explored.

RESULTS

Lys significantly reduced the cooking loss and improved the texture characteristics of Antarctic krill during heat treatment. The low-field nuclear magnetic resonance results showed that Lys reduced the water loss of Antarctic krill during heat treatment. Additionally, the surface hydrophobicity, Fourier transform infrared spectroscopy, and endogenous fluorescence spectroscopy results showed that Lys could inhibit the structural damage of Antarctic krill protein under the thermal denaturation condition and enhance the thermal stability of the protein. The scanning electron microscopy results showed that Lys could protect the structural integrity of Antarctic krill muscle fibers during heat treatment.

CONCLUSION

The cooking loss in the Lys added groups was better than the sodium tripolyphosphate added group, and 2.0% Lys solution could minimize the cooking loss of Antarctic krill. The secondary and tertiary structures of the Antarctic krill protein were actively protected by Lys during heat treatment. Overall, the study will provide insights into the application of Lys in the food industry as a natural additive and an alternative to phosphate. © 2021 Society of Chemical Industry.

Sensory profile of Parenica cheese varieties made from pasteurized cow’s milk

Parenica is a steamed, lightly smoked or unsmoked cheese wounded into a roll made from pasteurized cow's milk, with characteristic pronounced fibrous structure of curd. The aim of this work was to set up the sensory profile of smoked and unsmoked parenica cheese varieties made from pasteurized cow's milk and changes in sensory descriptors during 14 days of storage period at the temperature of 4 ±2 °C. Descriptive analysis was carried out by 18 trained assessors, who used a vocabulary of 26 terms to quantitatively describe appearance, aroma, consistency and taste of the experimental samples and also these overall sensory parameters with acceptability. Assessors evaluated the intensity of each descriptor by assigning the score on a 10 points linear scale. Analysis of variance found significant differences between cheese varieties (p <0.05) and the effect of storage period (p <0.05) on sensory quality of experimental parenica cheese varieties. The analysis showed that each sample group in observed representative sensory attributes was significantly different (p <0.05). Multiple factorial analysis showed in parenica cheese samples three selected components that explain more than 69% of the total variation in the dataset at the level of statistical significance p <0.05.

Quality improvement of spreadable processed cheese made from ultrafiltered milk retentates using commercial starter cultures

This study was undertaken to evaluate the feasibility of using commercial starter cultures for quality improvement of spreadable processed cheese manufactured from ultrafiltered milk retentates. Compared to control, six samples of ultrafiltered milk retentate were incubated at 25 ℃ with starter cultures CHN-22, FRC-60, and ABT-8. Three samples were incubated for 24 h and the others were incubated for 72 h. Physicochemical, microbiological, and organoleptic characteristics in all treatments during the 90-day cold storage (6 ± 2 ℃) period were determined. The results showed that protein content of all treatments was significantly lower than the control. Utilization of starter cultures in ultrafiltered processed cheese production increased titratable acidity, where titratable acidity of the treatments (PC_22-3, PC_60-3, and PC_8-3) was significantly higher than the other treatments and the control. PC_8-1, PC_60-1, and PC_22-1 treatments were the highest penetrometer readings and with low firmness. All treatments had higher water soluble nitrogen/total nitrogen%, total bacterial viable and lactic acid bacterial counts especially PC_22-3, PC_60-3, and PC_8-3 compared to the control. The results revealed that PC_60-1 and PC_22-3 treatments gained the highest acceptability scores than PC_60-3, PC_22-1, and the control.