Effect of inulin addition on the sensorial properties of reduced‐fat fresh cheese

A reduced‐fat fresh cow's milk cheese with inulin (3%) was compared with both full‐fat and reduced‐fat cheeses without the prebiotic. The pH and microbiological quality of cheeses were not affected by the presence of inulin. Cheeses produced with inulin were less hard, springy, cohesive and chewy than reduced‐fat cheeses, and more similar to cheeses made from whole milk. Cheeses produced with inulin had the lowest lightness and the highest yellowness values, although these colour differences were not detected by the panellists. The sensory panel described the reduced‐fat cheese with inulin as more acceptable than its counterpart without inulin.     

Influence of exopolysaccharide‐producing cultures on the volatile profile and sensory quality of low‐fat Tulum cheese during ripening

The objective of this investigation was to compare the composition and changes in the concentration of volatiles in low‐fat and full‐fat Tulum cheeses during ripening. Tulum cheese was manufactured from low‐ or full‐fat milk using exopolysaccharide (EPS)‐producing or non‐EPS‐producing starter cultures. A total of 82 volatile compounds were identified belonging to the following chemical groups: acids (seven), esters (21), ketones (14), aldehydes (six), alcohols (14) and miscellaneous compounds (20). The relative amounts of acids, alcohols and aldehydes increased in the cheeses made with EPS‐producing cultures during 90 days of ripening. Differences were found in the volatile profile of full‐fat Tulum cheese compared with the low‐fat variant, especially after 90 days of ripening. Exopolysaccharide‐producing cultures changed the volatile profile, and the EPS‐producing cultures including Streptococcus thermophilus + Lactobacillus delbrueckii subsp. bulgaricus + Lactobacillus helveticus (LF‐EPS2) produced cheese with higher levels of methyl ketones and aldehydes than the non‐EPS cultures. In the sensory analysis, full‐fat Tulum cheeses and the cheese produced with the EPS‐producing culture containing Lb. helveticus (LF‐EPS2) were preferred by the expert panel. It was concluded that the use of EPS‐producing starter cultures in the manufacture of low‐fat Tulum cheese had the potential to improve the flavour.     

Utilisation of a cell‐free extract of lactic acid bacteria entrapped in yeast to enhance flavour development in Cheddar cheese

A lactococcal cell‐free extract (CFE) was successfully entrapped in freeze‐dried attenuated yeast. The entrapment process involved passive diffusion of enzymes from the CFE into the yeast during hydration. The entrapped CFE was subsequently added during Cheddar cheese production and its impact on a range of ripening parameters compared to added attenuated yeast or CFE alone. Statistically significant differences were evident for secondary proteolysis, sensory attributes and volatiles, which were related to enhanced enzymatic and metabolic activity from the attenuated yeast and entrapped CFE. This study highlights the potential of attenuated yeast as a vector to augment flavour development in Cheddar cheese.     

Physicochemical properties of low‐fat soft cheese Turkish Beyaz made with bacterial cellulose as fat mimetic

The effects of incorporating various concentrations of bacterial cellulose (BC) (1.7 and 3.5% w/v) on the physicochemical and sensorial properties of low‐fat soft cheese Turkish Beyaz were investigated during a 60‐day ripening period. Control cheeses were produced using nonfat, half‐fat (1.7% fat) and full‐fat milk, for comparison. Depending on changing fat percentage, some physicochemical properties of cheeses, such as moisture, pH and salt showed significant differences, but BC had no influence on these properties. Fat content and BC altered the textural and sensory properties. These results indicated that BC improved the quality of reduced‐fat and low‐fat Turkish Beyaz cheeses.     

Proteolysis texture and microstructure of low‐fat Tulum cheese affected by exopolysaccharide‐producing cultures during ripening

The objective of the study was to determine the effects of exopolysaccharide (EPS)‐producing or non‐EPS‐producing starters on proteolysis, physical and microstructural characteristics of full‐fat or low‐fat Tulum cheeses during ripening. For this purpose, Tulum cheese was manufactured using full‐ or low‐fat milk with EPS‐producing and non‐EPS‐producing starter cultures. Chemical composition, proteolysis, texture profiles and microstructure of the cheeses were studied during 90 days of ripening. Urea‐PAGE of water‐insoluble and RP‐HPLC peptide profiles of water‐soluble fractions of the cheeses showed that the use of starters resulted in different degradation patterns in all cheeses during ripening. Although β‐casein exhibited similar degradation patterns in all cheeses, small differences are present in α_s1‐casein degradation during ripening. Reducing fat in Tulum cheese changed the RP‐HPLC peptide profile of the cheeses. The use of EPS‐producing cultures improved the textural characteristics and changed the microstructure and proteolysis of low‐fat Tulum cheese.     

The effect of adding enzyme‐modified cheese on sensory and texture properties of low‐ and high‐fat cream cheeses

The influence of enzyme‐modified cheese (EMC) and fat content on sensory and texture properties of cream cheese was investigated. Enzyme‐modified cheese and fat content were set at three levels each, and organoleptic and texture properties for all experimental cheeses were then determined. Data were analysed using response surface methodology. Both design parameters had significant influence on sensory and texture properties. The EMC did not alter hardness significantly, whereas the higher fat formula had the higher hardness. The results indicated that the optimum level of EMC was less than 1% for high‐fat cream cheeses and at least 5% for low‐fat cream cheeses.     

Proteolysis and textural properties of low‐fat ultrafiltered Feta cheese as influenced by maltodextrin

Maltodextrin was used as a fat replacer in low‐fat ultrafiltered cheese. Fat was replaced with 25% maltodextrin milk solution (w/w) in cheese at 15 and 50% (w/w). The chemical, rheological and sensory properties as well as the microstructure of the cheese samples were evaluated after storage for 2 months at 8 °C. Maltodextrin affected the chemical (pH, dry matter, fat, water‐soluble nitrogen to total nitrogen, nonprotein nitrogen to total nitrogen, total free amino acid) and rheological (mean relaxation time) properties, as well as the microstructure. In general, based on textural properties, sensory evaluation and economic aspects, the 50%‐fat‐reduced sample was selected as the best treatment.     

Study of macromolecular interactions in low‐fat brined cheese modified with Zedu gum

The functionality of Zedu gum as a fat mimetic in low‐fat brined cheese was studied. The physicochemical, textural, rheological, microstructural and sensory properties of cheese samples modified with 0.1% and 0.25% of Zedu gum were compared to those of control cheeses (low‐fat and full‐fat cheeses with no fat mimetic) during ripening. To obtain further information about the cheeses' structure and interactions between macromolecules (casein protein and Zedu gum), other parameters were analysed by differential scanning calorimetry and Fourier transform infrared (FTIR) spectroscopy. Incorporation of Zedu gum into low‐fat cheese caused an open microstructure and softer texture in comparison with the control low‐fat cheese. The thermal properties and FTIR spectra of the cheeses were influenced by both fat mimetic and ripening time. On days 1 and 60 of ripening time, the lower value of enthalpy of the low‐fat cheese with 0.25 g of Zedu gum/kg of milk (AS 0.25) in comparison with control low‐fat cheese could have been due to the electrostatic nature of the interactions between Zedu gum and casein protein. On both days, the FTIR spectrum of AS 0.25 showed a well separated absorption at 1746 cm^?1 possibly due to the formation of ester groups as a result of the interaction of the carbonyl groups in Zedu gum with the hydroxyl groups of some amino acids in casein.     

Extending the shelf life of fresh ewe’s cheese by modified atmosphere packaging

This study evaluated the effect of modified atmosphere packaging (MAP) in extending the shelf life of a fresh ewe’s cheese stored at 4 °C for 21 days. Three batches were prepared with 20, 30 or 50% CO₂ with N₂ as filler gas. MAP controlled well the microbial growth, and the best result was obtained with 50% CO₂. Pathogens were not detected in any sample. Softening of cheese was best reduced by 30% or 50% CO₂. The sensory characteristics of the cheeses markedly decreased during storage. Only the sample stored with 50% CO₂ obtained an overall score above the acceptability at 14 days.     

Changes in the texture,physicochemical properties and volatile compound profiles of fresh Kashar cheese (<90 days) during ripening

In this study, four different fresh Kashar cheese samples were ripened for 90 days. The physicochemical properties, texture attributes, fatty acid composition and volatile compound profiles of the samples were measured every 30 days of ripening. The texture properties of the cheese samples were significantly affected by the duration of the ripening period. The results of this study highlighted that texture parameters as a function of ripening period should be considered for both fresh and aged Kashar cheeses to determine the ripening period as they are very important for consumer acceptability and consumption of the end product.     

Influence of fat replacers on the chemical,textural and sensory properties of low‐fat Beyaz pickled cheese produced from ewe's milk

In this study, low‐fat Beyaz pickled cheeses were produced from ewe's milk using a protein‐based fat replacer (1.0% w/w Simplesse^®), a carbohydrate‐based fat replacer (0.5% w/w Maltrin^®) and a blend of both (0.5% w/w Simplesse^® + 0.25% w/w Maltrin^®). The chemical, textural and sensory properties of cheeses were examined during storage for 60 days. The use of fat replacers affected chemical (except pH and acidity), textural and sensory properties of the cheeses. The cheeses produced with Simplesse^® (Sample B) were similar to full‐fat cheese and had the highest sensory scores.     

Enzymatic extract from flowers of Algerian spontaneous Cynara cardunculus: Milk‐clotting properties and use in the manufacture of a Camembert‐type cheese

The aim of this study was to assess the coagulant properties of crude extract from cardoon flowers (CECF) as a replacement for the imported coagulants used in the local Algerian cheese factories. Optimal coagulation activity of the extract was observed at pH 5 and 60 °C with a CaCl₂ concentration of 0.02 M. The electrophoretic pattern revealed that the crude extract contains mainly cardosins A and B. The study of interactions involved in the formation of milk gel coagulated by CECF showed that hydrogen forces, hydrophobic interactions and calcium bridges contributed highly to the formation of milk gel. Camembert‐type cheese obtained by CECF was judged by trained panellists and was found to be in agreement with standard specifications. The present study highlights the possibility of using Algerian CECF as a promising plant coagulant in cheesemaking for the dairy industry.     

The effect of using an exopolysaccharide‐producing culture on the physicochemical properties of low‐fat and reduced‐fat Kasar cheeses

A mixed starter culture containing exopolysaccharide (EPS)‐producing strains of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was combined with Lactobacillus helveticus LH301 and used in the manufacture of low‐fat and reduced‐fat Kasar cheeses. For comparison, low‐fat (C10) and reduced‐fat (C20) cheeses were made using EPS‐producing (EPS⁺) starter strain and EPS‐non‐producing (EPS^?) starter strain. The physicochemical properties of the cheeses were assessed in terms of chemical composition, texture, microstructure and microbial content over 90 days. Cheeses made with EPS‐producing culture (EPS10 and EPS20) had lower protein contents than control cheeses with 10% and 20% fat in dry basis (C10 and C20). Scanning electron microscopy images showed that using EPS‐producing culture resulted in a less compact protein matrix and sponge‐like structure in the cheese samples. In general, cheeses made using EPS‐producing culture had lower total viable counts. This could be related to the reduced survivability of EPS‐producing cells in the cheese matrix during ripening due to autolysis ability.     

The effect of quinoa germ on the quality properties of fresh whey-less cheese made by ginger (Zingiber officinale) extract as a coagulant

The effect of ginger extract (GE), as a milk coagulant, was investigated on the physicochemical, proteolysis, textural profiles and sensory properties of whey-less cheese containing quinoa germ powder (QGP; 0, 3, 6 and 9%) during storage. The results showed that with increasing QGP, the dry matter, fat, soluble nitrogen at pH 4.6 and free tryptophan and tryptophan amino acids increased and protein content decreased. Consequently, it is suggested that using 6% quinoa germ in the production of whey-less cheese made by GE as a coagulant can give the most desired product with no adverse effects on the quality and sensory properties.     

A dual‐acidification process for the manufacture of direct‐acidified Cottage cheese

A technology is described for manufacturing Cottage cheese which involved initial cold (4 °C) acidification of milk with HCl to bring down the pH to 5.3 followed by tempering slowly to 15 °C and subsequent acidification through slow hydrolysis of glucono delta lactone, resulting in a drop in pH to 5.0 and thereafter renneting at 20 °C followed by setting and cutting of curd and subsequent cooking at 35 °C for ~30 min. The method enabled manufacturing of Cottage cheese curd with average moisture, curd yield and curd hardness being 74.30%, 11.88% and 648.30 mN, respectively.     

Effect of homogenisation of cheese milk and high‐shear mixing of the curd during cream cheese manufacture

The role of the homogenisation pressure of cheese milk (0, 25, 100 MPa) and high‐shear mixing of cheese curd at different speeds (750, 1500, and 3000 r.p.m.) and times (2 and 4 min) in improving the texture of medium‐fat cream cheese was investigated independently. Homogenisation resulted in small fat globules and firmer texture, while increasing speed and mixing times resulted in a decrease in curd particle size and an increase in the spreadability of the cheese. All curd samples from both the trials exhibited shear‐thinning behaviour. Unhomogenised milk and high‐shear mixing of the curd showed a low coefficient of friction (better lubrication property).     

Seasonal changes in the fat composition of Lacha sheep's milk used for Idiazabal cheese manufacture

 The effect of the seasonality of lacha sheep's milk production on the milk-fat composition was studied. This raw milk is used to manufacture Idiazabal cheese, a typical product of the Basque Country of northern Spain. Milk samples were taken, prior to cheesemaking, from a refrigerated tank of mixed milk from different flocks in a cheese factory in February, April and June. The triglyceride and fatty acid composition of the milk were analysed. The results showed that the molecular characteristics of the milk-fat components, the degree of unsaturation and the chain length changed with the time of the year. The June milk had a higher content of unsaturated and long-chain fatty acids and triglycerides. The April and February milks were very similar, with a higher content of saturated and short-chain fatty acids and triglycerides. The differences in animal feeding are probably the most important factor affecting milk composition because in June flocks are fed mainly in natural pastures while in April and February the ewes are also fed additional commercial feeds. Idiazabal cheeses were considerably different from February to June, suggesting a relationship between the free fatty acid composition of the cheese, its sensorial properties and the fat composition of the raw milk used in cheesemaking. Received: 18 June 1999     

The effect of wild lactic acid bacteria on the production of goat’s milk soft cheese

A blend of four wild strains of lactic acid bacteria, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus paracasei subsp. paracasei and Enterococcus faecalis, was used as starter to produce a goat’s milk soft cheese. The cheese was analysed microbiologically, physicochemically and organoleptically through a 30‐day period of ripening. Counts of the starter cultures increased in the first 24 h and then remained stable during ripening. Yeasts and coliforms were found at low numbers initially and gradually decreased to undetectable levels. Micrococcal counts were high throughout ripening. The end product was a soft cheese characterised by a mild, aromatic taste as well as a smooth structure.     

The effect of varying casein/fat ratio on physicochemical and sensory qualities of Feta‐type cheese made using buffalo milk

The Feta‐type cheese was prepared with different casein/fat (C/F) ratios of buffalo milk using microbial rennet. The manufactured Feta cheeses were subjected to physicochemical and sensory quality at 15‐day interval up to 60 days of ripening. Sensory analysis discriminated the different level of C/F ratio of buffalo milk cheeses predominantly by age. There was no significant difference (P < 0.01) observed in cheese made from C/F ratio of 0.6–0.7 in terms of flavour. The titratable acidity (TA), soluble protein and free fatty acid appear to be age‐dependent and increased throughout the ripening in all experimental cheeses.