Yield and functionality of Cheddar cheese as influenced by homogenization of cream

Cheese milk was standardized (casein-to-fat ratio of 0.7) by blending 0.64% fat milk and 35% fat cream. Cream was homogenized at 0/0 MPa (CO), 3.5/3.5 MPa (H05), 6.9/3.5 MPa (H10) or 10.4/3.5 MPa (H15). Cream homogenization did not influence rennet-clotting time, but it increased rate of curd firming and increased curd firmness of cheese milk. Moisture and salt in moisture phase of cheese increased with homogenization. Moisture (37%) and salt (1.5%) adjusted yield increased 1.42, 3.44 and 3.85% in H05, H10 and H15, respectively, over CO. Homogenized treatment cheeses melted faster with age. Free oil in 1 week old cheeses was lowest in H10 and highest in H05 and increased in all treatments with age. Cheese hardness was not influenced by homogenization but decreased with age. Cheeses with homogenized cream had improved body and texture and flavor. Cream homogenized at 6.9/3.5 MPa was optimal for enhancing Cheddar cheese yield and functionality.     

Investigating individual preferences in rating and ranking conjoint experiments. A case study on semi-hard cheese

Stated preference conjoint experiments and self-explicated measures based on rating and ranking approaches were conducted to investigate Norwegian consumers’ choices among healthier and organically produced semi-hard cheeses. In the conjoint experiments, one group of participants (n = 114) performed a rating task of eight cheeses whereas the other group (n = 105) performed a ranking task of the same cheeses, all based on pictorial stimuli only. Then, all participants performed self-explicated rating and ranking evaluations of the cheese attributes. Conjoint rating data were analysed by mixed model ANOVA, while conjoint ranking data were analysed by mixed logit. The different approaches are compared in terms of data analysis methodologies, outcomes and practicalities for the experimenter as well as for the respondents. Rather than average population effects, focus is brought on individual preferences and consumer segmentation. Findings reveal that the two conjoint experiments lead to similar population effects and consumer segments. Consumers on average prefer cheeses of new (healthier) fat composition, organic production and lower price to cheeses of regular fat composition, conventional production and higher price. Two consumer segments are investigated. Consumers in the New fat segment are health-conscious, whereas consumers in the Regular fat segment are attracted by conventional cheese and lower prices. Self-explicated ratings of the cheese attributes corroborate these findings.     

Applicability of extracts from Centaurea calcitrapa in ripening of bovine cheese

Aqueous extracts obtained from cell suspension cultures of Centaurea calcitrapa were used as proteolytic additive in the manufacture of a commercial bovine cheese, coagulated with animal rennet and typically ripened for 28 d. The cheese was assessed in comparison to standard cheese for two levels of addition of said extract, viz. 0.61 and 1.22 mg of total protein mL⁻¹. The qualitative and quantitative evolutions of the nitrogen fractions were monitored in the experimental cheeses throughout the whole ripening period. In general, the chemical compositions of the cheeses were different depending on the amount of extract used, but no significant differences could be detected in the ripening index. With regard to electrophoretic profiles, the two types of cheese could be distinguished until up to ca. 7 d of ripening, but differences did essentially vanish by 28 d.     

Evolution of lipolysis during the ripening of traditional Feta cheese

Lipolysis was studied during ripening of traditional Feta cheese produced in two small dairies, A and B. The cheeses were made from a thermized mixture of ewes’/goats’ milk by using yoghurt as starter and artisanal rennet from lambs’ and kids’ abomasa (cheese A) or mixed artisanal rennet with calf rennet (cheese B).The acid degree value and the free fatty acids (FFA) contents in both cheeses increased sharply up to 18 d (pre-ripening period at 15 °C) and continued to increase throughout ripening. In both mature cheeses, acetic acid was found at high levels (13–18% of the total FFAs). However, except for this, all FFA contents differed significantly (P < 0.05) between the two cheeses throughout ripening. The levels of individual and total C2:0–C8:0, C10:0–C14:0 and C16:0–C18:2 fatty acids were significantly higher (P < 0.05) in cheese A than in cheese B. Presumably the difference, especially in the C2:0–C8:0 content, was due mainly to the type of the rennet used. Butyric acid was the dominant FFA in cheese A (20% of the total FFAs at 120 d), while the most abundant FFAs in cheese B were capric (18%) and lauric acid (18%). In general, the lipolysis degree of the two cheeses was higher than those reported for the industrially-made Feta cheese.In organoleptic evaluation, cheese A had a piquant taste that was attributed to its high content of butyric acid and showed a significantly (P < 0.05) higher total score than cheese B.     

Use of high-pressure-treated milk for the production of reduced-fat cheese

Pasteurized (65°C, 30 min), pressurized (400 MPa, 22°C, 15 min) and pasteurized–pressurized milks were used for reduced-fat (approximately 32% of total solids) cheese production. Pressurization of milk increased the yield of reduced-fat cheese through an enhanced β-lactoglobulin and moisture retention. In addition, pressurisation of pasteurized skim milk improved its coagulation properties. The cheeses made from pasteurized–pressurized and pressurized milks showed a faster rate of protein breakdown than the cheese made from pasteurized milk, that might be mainly attributed to a higher level of residual rennet. Hardness of the experimental cheeses, as determined by both the sensory panel and instrumental analyses, decreased as the moisture content and proteolytic degradation of the cheese increased (pasteurized>pressurized>pasteurized–pressurized). In general terms, pressurization of reduced-fat milk prior to cheese-making improved cheese texture and thus accounted for a higher overall acceptability, except for the cheeses made from pasteurized–pressurized milk at 60 d of ripening, whose acceptability score was adversely affected by bitterness.     

PANCA: Panel concordance analysis

This paper proposes panel concordance analysis (PANCA) as a tool for panel leaders to identify disconsensus between the panelists on the sensory attributes used. PANCA summarizes the sensory data ([products × panelists × replicates] × attributes) by a low-rank approximation which is penalized for disconsensus (disagreement) between the panelists. When all the panelists agree on the sensory attributes used, the disconsensus penalty will have a negligible effect. However, if the assumption of good consensus is not supported by the data, considerable residual errors will arise. Consequently, PANCA can be used to identify difficult sensory attributes or even poor/deviating panelists which requires further training or could call for an alternative data processing strategy. It is also demonstrated that PANCA can be used to apply a multivariate ANOVA decomposition like in ASCA (ANOVA simultaneous component analysis). Theory and applications are explained by means of a real-life example from industrial sensory practice.     

A comparison of the chemical,microbiological and sensory characteristics of bovine and ovine Halloumi cheese

Commercial samples of fresh and mature Halloumi cheeses made from ovine or bovine milk were studied in order to establish their chemical, microbiological and sensory characteristics. Significant differences were observed between the two types of Halloumi cheese both when fresh and mature. The free volatile fatty acid (FVFA) content of the cheeses increased with maturation from 483 to 1356 mg kg⁻¹ for the ovine product, but lower values (380–1248 mg kg⁻¹) were found in the bovine cheese. During maturation for 40 days, Enterococcus faecium, which dominated the microflora of fresh ovine cheese, was replaced by lactobacilli, including a new species, Lactobacillus cypricasei, which was not found in the bovine samples. Fewer than 100 cfu g⁻¹ lactic acid bacteria (LAB) were present in the fresh bovine cheeses, but a microflora dominated by lactobacilli developed with time. Yeast counts in the mature ovine and bovine cheeses reached 2.3–2.8×10⁵ cfu g⁻¹ and, as some of the yeasts were proteolytic and/or lipolytic, it was assumed that they were having a positive impact of the flavour of the cheeses. The sensory panel distinguished significant differences in texture and flavour between the fresh and mature samples of both ovine and bovine cheeses and, overall, there was a significant preference for the ovine brand.     

Effect of cream homogenization on textural characteristics of low-fat Iranian White cheese

The effects of cream homogenization of cheese making milk on textural and sensory characteristics of Iranian White cheese were studied. Cream was homogenized in a two-stage homogenizer at 6.0/2.5 or 9.0/2.5 MPa. Cheese samples were analyzed for rheological parameters (uniaxial compression and small amplitude oscillatory shear), meltability, microstructure, and sensory characteristics. Cream homogenization increased fat content leading to increased meltability. This effect increased as the homogenization pressure increased. The values of storage modulus, stress at fracture and Young's modulus of elasticity for cheeses from homogenized treatments were lower than those of unhomogenized cheese. Cream homogenization at 6.0/2.5 MPa effectively improved the textural, functional and sensory characteristics and enhanced the yield of low-fat Iranian White cheese. This cheese had the lowest values of storage modulus and stress at fracture, probably due to the high number of small, evenly dispersed fat globules in microstructure and especially its lower protein content. Cheeses with homogenized cream had improved texture, flavor and appearance.     

An investigation of matches of bottom fermented red beers with cheeses

This study was designed to explore the hedonic response of consumers to cheese and beer pairings by tasting in a typical social environment of consumption. Ninety-six regular beer and cheese consumers hedonically rated all fifty-six pairings of eight bottom fermented red beers and seven cheeses (Parmigiano Reggiano, Fontina, Taleggio, Smoked Provola, Mozzarella, Caprino, and Gorgonzola).Preference varied across samples (p < 0.001). One consumer out of two appreciated all of the pairings, yet pairings with Mozzarella were liked moderately. One consumer out of three appreciated pairings with Parmigiano, were neutral in their hedonic response to pairings with Fontina and disliked moderately the remaining pairings but those including mozzarella were extremely unappealing to them. One consumer out of six disliked all the pairings tested but some matches with Parmigiano were liked slightly. Liking of cheese and bottom fermented red beer pairings is biased by the type of cheese partnered with beer (Parmigiano most liked and Mozzarella least liked); by the type of beer partnered with cheese, and by the liking of the sensory properties of the beers and of the cheese tasted alone. However, consumers do not simply enjoy a combination of their most preferred beer and cheese. They identified some flavors that harmonize better than do others. Also, significant correlations between mean liking scores and sensory characteristics of the fifty-six pairings were found. Beer flavor is modified largely by prior cheese consumption. Each cheese has an effect on beer flavor and this effect is consistent over the eight different beers. In general all of the cheeses decreased the intensity of fruitiness, sweetness, perceived level of carbonation, perceived level of alcoholicity, caramel-like, licorice-like and burnt notes. Bitterness, astringency, and burnt notes were reduced by most of the cheeses but Fontina and Smoked Provola increased the perception of these attributes. For brewers to profitably exploit the potential of the science of cheese and beer pairing the choice of a suitable beer and of a suitable cheese in terms of liking and sensory properties and the identification of a proper target audience familiar to the beers paired with cheese are essential.     

A preliminary study on the role of alkaline phosphatase in cheese ripening

A preparation of exogenous alkaline phosphatase (ALP), containing 17,500 mU L⁻¹, was added to pasteurized milk (PM) to study its role in cheese ripening. Three miniature Cheddar-type cheeses were made from PM containing no added ALP (control), PM plus 23 μL ALP (T1), to give ALP concentration similar to that in raw milk, and PM plus 46 μL ALP (T2). Milk, after addition of ALP, was held at 6 °C for 12 h before cheese manufacture and the experiment was replicated three times. The control, T1 and T2 milks contained ALP activity of 415, 2391 and 4705 mU L⁻¹, respectively. The addition of ALP to PM caused significant (P<0.05) changes in moisture content of miniature cheeses but did not cause any changes in protein content. Levels of water-soluble N during ripening of the cheeses were similar for control, T1 and T2 cheeses. The concentration of amino acids was not affected by the level of ALP present in milk. However, reversed-phase HPLC showed differences in the peptide patterns of control, T1 and T2 cheeses, suggesting a role of ALP in cheese ripening. The results suggest that ALP may play a role in cheese ripening, but further studies are needed to confirm this.     

Improving the viability of Bifidobacterium bifidum BB-12 and Lactobacillus acidophilus LA-5 in white-brined cheese by microencapsulation

The viability of Bifidobacterium bifidum BB-12 and Lactobacillus acidophilus LA-5 microencapsulated by either an extrusion or an emulsion technique and used in white-brined cheese was monitored. Both microencapsulation techniques were effective in keeping the numbers of probiotic bacteria higher than the level of the therapeutic minimum (>10⁷ cfu g^?1). While the counts of probiotic bacteria decreased approximately 3 log in the control cheese in which probiotics were used as free cells, the decrease was more limited in the cheeses containing microencapsulated cells (approximately 1 log). Medium- and long-chain free fatty acid contents of the cheeses with immobilized probiotics were much higher than in the control cheese. Similarly, cheeses made with immobilized probiotics contained higher acetaldehyde and diacetyl levels than the control. Experimental cheeses containing microencapsulated probiotics were not different from the control cheese in terms of sensory properties.     

Texture characteristics and pizza bake properties of low-fat Mozzarella cheese as influenced by pre-acidification with citric acid and use of encapsulated and ropy exopolysaccharide producing cultures

Low-fat Mozzarella cheeses containing 6% fat were made by pre-acidification of milk with citric acid to pH 6.1 and using encapsulated ropy or non-ropy exopolysaccharide (EPS) producing Streptococcus thermophilus. Moisture retention, changes in texture profile analysis (TPA), meltability and stretchability of cheese, and changes in colour, surface scorching and shred fusion were analysed after baking over 90 days (d). Control cheeses and those made from pre-acidified milk without EPS cultures had the lowest moisture content at 54.84% and 55.28%, respectively. Control cheeses were hardest and their meltability and stretchability were initially low. Hardness was reduced and the melt and stretch distances increased with time. When baked, control cheeses showed incomplete shred fusion. Pre-acidification reduced hardness and increased meltability. Capsular- and ropy-EPS were quantified at 30.42 and 30.55 mg g⁻¹ of cheese, respectively, and increased moisture retention in pre-acidified cheese to 56.67% and 56.21%, respectively. These cheeses were softer and exhibited lower springiness. Greater meltability was observed initially but became similar to control cheeses after 90 d of storage. When baked after 45 d of storage, cheeses containing EPS producing cultures showed improved shred fusion, meltability and a reduction in surface scorching.     

Ripening of Cheddar cheese made from blends of raw and pasteurised milk

Cheddar cheeses were made from pasteurised milk (P), raw milk (R) or pasteurised milk to which 10 (PR10), 5 (PR5) or 1 (PR1) % of raw milk had been added. Non-starter lactic acid bacteria (NSLAB) were not detectable in P cheese in the first month of ripening, at which stage PR1, PR5, PR10 and R cheeses had 10⁴, 10⁵, 10⁶ and 10⁷ cfu NSLAB g⁻¹, respectively. After ripening for 4 months, the number of NSLAB was 1–2 log cycles lower in P cheese than in all other cheeses. Urea–polyacrylamide gel electrophoretograms of water-soluble and insoluble fractions of cheeses and reverse-phase HPLC chromatograms of 70% (v/v) ethanol-soluble as well as -insoluble fractions of WSF were essentially similar in all cheeses. The concentration of amino acids were pro rata the number of NSLAB and were the highest in R cheese and the lowest in P cheese throughout ripening. Free fatty acids and most of the fatty acid esters in 4-month old cheeses were higher in PR1, PR5, PR10 and R cheeses than in P cheese. Commercial graders awarded the highest flavour scores to 4-month-old PR1 cheeses and the lowest to P or R cheese. An expert panel of sensory assessors awarded increasingly higher scores for fruity/sweet and pungent aroma as the level of raw milk increased. The trend for aroma intensity and perceived maturity was R>PR10>PP5>PR1>P. The NSLAB from raw milk appeared to influence the ripening and quality of Cheddar cheese.     

Lipolysis in reduced sodium Feta cheese made by partial substitution of NaCl by KCl

Feta cheese (five trials) of different sodium content was made from split lots of curd by varying the salting procedure, i.e. dry salting with NaCl (control) or mixtures of NaCl/KCl (3 : 1 or 1 : 1, w/w basis) and filling the cans with brine made with NaCl or the above NaCl/KCl mixtures, respectively. Lipolysis in cheese was monitored during aging by using the acid degree value (ADV) method and gas chromatography (GC). It was found that the ADVs of control and experimental cheeses were similar (P>0.05) at all sampling ages (3, 20, 40, 60, 120 and 240 d). Moreover, the results of GC showed that there were neither qualitative nor significant (P>0.05) quantitative differences in the individual free fatty acids (FFA) of the control and experimental cheeses at the ages of 40 and 120 d. These findings indicated that the partial substitution of NaCl by KCl in the manufacture of Feta cheese had no effect on lipolysis during cheese aging.     

Effect of commercial adjunct cultures on proteolysis in low-fat Kefalograviera-type cheese

The effect of two commercially available adjunct cultures, LBC 80 (Lactobacillus casei subsp. rhamnosus) and CR-213 (containing Lactococcus lactis subsp. cremoris and Lc. lactis subsp. lactis) on the proteolysis in low-fat hard ewes’ milk cheese of Kefalograviera-type was investigated. Two controls, a full-fat cheese (306 g kg⁻¹ fat, 378 g kg⁻¹ moisture) and a low-fat cheese (97 g kg⁻¹ fat, 486 g kg⁻¹ moisture, made using a modified procedure), were also prepared. The effect of adjunct culture on proteolysis, as examined by polyacrylamide gel electrophoresis of cheese and water soluble cheese extracts, was marginal. The reverse-phase HPLC peptide profiles of the water soluble extracts from low-fat cheeses were similar although some quantitative differences were observed between low-fat control cheese and experimental cheeses. The fat content as reflected by the differences in peptide profiles affected the pattern of proteolysis. Proteolysis, as measured by the percentage of total nitrogen soluble in water or in 120 g L⁻¹ trichloroacetic acid, was significantly (P<0.05) affected by the addition of adjunct cultures. Furthermore, the adjunct cultures enhanced the production of low molecular mass nitrogenous compounds; the levels of total nitrogen, soluble in 50 g L⁻¹ phosphotungstic acid, and of free amino acids were significantly (P<0.05) higher in the low-fat experimental cheeses than in the low-fat control cheese.     

Effect of combinations of high-pressure treatment and bacteriocin-producing lactic acid bacteria on the survival of Listeria monocytogenes in raw milk cheese

The combined effect of high-pressure (HP) treatment and bacteriocin-producing lactic acid bacteria (BP-LAB) on the survival of Listeria monocytogenes Scott A in cheeses made from raw milk that was inoculated with the pathogen at 4.80 log cfu mL⁻¹, a commercial starter and one of seven strains of BP-LAB was investigated. On day 3, the counts of L. monocytogenes were 7.03 log cfu g⁻¹ in a control cheese (without BP-LAB, not HP treated), 6.06–6.74 log cfu g⁻¹ in cheeses with BP-LAB, 6.13 log cfu g⁻¹ in a cheese without BP-LAB and treated on day 2 at 300 MPa, 2.01 log cfu g⁻¹ in a cheese without BP-LAB and treated on day 2 at 500 MPa, 3.83–5.43 log cfu g⁻¹ in cheeses with BP-LAB and treated on day 2 at 300 MPa, and 1.81 log cfu g⁻¹ or less in cheeses with BP-LAB and treated on day 2 at 500 MPa. HP treatment was more effective on day 51 than on day 2.     

Identification of bioactive peptides in commercial Cheddar cheese

This study examined the presence of antimicrobial, antioxidant and antihypertensive peptides in three commercially available Australian Cheddar cheeses. Peptide extracts as well as fractionated peptide extracts were examined. Commercial cheese A peptides exhibited the greatest inhibition against Bacillus cereus and also commercial cheese A fractionated peptides greater than 10 kDa showed the highest inhibition against B. cereus. Commercial cheese A peptides also showed the highest inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH), a free radical used to measure antioxidant activity. All cheese fractionated peptides greater than 10 kDa demonstrated higher inhibition of DPPH after fractionation. Antihypertensive peptides were determined by inhibition of the angiotensin-converting enzyme (ACE). Overall, commercial cheese A had the lowest concentration required to inhibit ACE and commercial cheese A fractionated peptides lower than 5 kDa had the lowest inhibition after fractionation. These preliminary findings suggest that peptide extracts of three commercial Australian Cheddar cheeses exhibit antimicrobial, antihypertensive and antioxidant properties.