Role of salt in Iranian ultrafiltered Feta cheese: Some textural and physicochemical changes during ripening

Sodium Reduction by Partial and Total Replacement of NaCl with KCl in Serbian White Brined Cheese

Cheese has been listed as one of four priority food groups intended for salt reduction reformulation. The present study aimed to investigate the possibility of producing Serbian white brined cheese (Homoljski Sir) with half of NaCl, three quarters of NaCl and all NaCl replaced with KCl (Na50, Na25 and Na0, respectively). Basic composition, proteolysis and texture profile parameters were monitored during 60 days of ripening. At the end of ripening, an acceptance test was conducted by untrained consumers (N = 46). According to the cluster analysis based on hedonic scores, three clusters emerged: male consumers (47.8%), agreeable consumers (30.4%) and highly educated female consumers (21.8%). Both partial and a total salt replacement had no effect on the course of proteolytical changes, the texture and basic composition during ripening. Female consumers did not accept any level of salt substitution, while male consumers showed dislike only for the Na0 cheese. Almost 80% of all consumers liked moderately-to-very-much the Na25 cheese variant. It implies that it is worth considering the production of cheese with 50–75% of NaCl replaced with KCl. The addition of natural flavoring and clear labeling of the sodium reduction should accompany the salt replacement strategy.

Genomic and Metabolic Features of an Unexpectedly Predominant, Thermophilic, Assistant Starter Microorganism, Thermus thermophilus, in Chinese Inner Mongolian Cheese

Inner Mongolian cheese is a traditional dairy product in China. It is produced without rennet, using naturally acidified milk that is simmered to achieve whey separation. In order to analyse the impact of simmering on the microbial community structure, high-throughput sequencing was performed to obtain bacterial 16S rRNA sequences from cheeses from the Ordos (ES), Ulanqab (WS), Horqin (KS) and Xilingol (XS) grasslands of Inner Mongolia. The relative abundance of an unexpected microorganism, Thermus thermophilus, ranged from 2% to 9%, which meant that its dominance was second only to that of lactic acid bacteria (LABs). Genome sequencing and fermentation validation were performed in T. thermophilus N-1 isolated from the Ordos, and it was determined that T. thermophilus N-1 could ingest and metabolise lactose in milk to produce lactate during the simmering process. T. thermophilus N-1 could also produce acetate, propionate, citrate and other organic acids through a unique acetate production pathway and a complete propionate production pathway and TCA cycle, which may affect texture and flavour development in Inner Mongolian cheese. Simultaneously, the large amount of citrate produced by T. thermophilus N-1 provides a necessary carbon source for continuous fermentation by LABs after the simmering step. Therefore, T. thermophilus N-1 contributes to cheese fermentation as a predominant, thermophilic, assistant starter microorganism unique to Chinese Inner Mongolian cheese.

Development and characterization of probiotic UF Feta cheese containing Lactobacillus paracasei microencapsulated by enzyme based gelation method

In this study probiotic microcapsules with three different shell compositions were produced through enzymatic gelation of skim milk powder by rennet, skim milk powder by transglutaminase and sodium caseinate by transglutaminase. Fabricated microcapsules and free Lactobacillus paracasei cells were incorporated into Iranian UF Feta cheese with different salt levels. Viability of L. paracasei (LAFTI L26), antioxidative capacity, ripening index, titrable acidity, salt content and texture profile analysis (TPA test) parameters including hardness, cohesiveness and stringiness were monitored during 45 days of storage time. Rennet based encapsulation was the most efficient method and could keep L. paracasei viable in all cheese samples (> 7 log10 CFU/g) at the end of storage time. Proteolysis pattern and acidification rate were strongly influenced by shell composition, salt level and storage time. Hardness and stringiness of probiotic cheese samples were influenced by shell composition of microcapsules and storage time but cohesiveness was only dependent on storage time. Therefore, storage time was the only effective factor on free radical scavenging activity of cheese samples.