FAT REPLACERS IN LOW-FAT MEXICAN MANCHEGO CHEESE

Low-fat Manchego cheeses (15 g fat/L milk) were prepared with three commercial fat replacers consisting of low methoxyl pectin (LMP), whey protein concentrate (WPC) and microparticulated whey protein (MWP). A low-fat cheese (15 g fat/L milk) without added fat replacer and a full-fat cheese (30 g fat/L milk) were prepared as controls. Cheeses were matured thirty days prior to instrumental texture profile analysis, microstructure analysis, and discriminative sensory evaluation. Scanning electron micrographs showed that the low-fat cheeses incorporating the LMP and WPC fat replacers lost the compact and dense protein matrix characteristic of the low-fat control cheese and exhibited hardness, springiness, cohesiveness and chewiness similar to the full-fat control cheese. No significant difference was found in the sensory characteristics between the full-fat control cheese and the cheese incorporating WPC.     

Characteristics of traditional Croatian ewe's cheese from the island of Krk

Krk cheese is a hard, full-fat cheese made from raw sheep's milk, characterized by a delicate, full and strong flavour. The aim of this study was to determine farm influence on the chemical composition of sheep's milk for Krk cheese production, and the chemical characteristics of Krk cheese during ripening. Gross composition of the milk used complies with the average sheep's milk composition from the Croatian Adriatic region. During ripening, fat, protein, salt content and lactic acid concentration increased ( P <  0.01), as well as the water-soluble nitrogen fraction and the 12%-trichloroacetic-acid-soluble nitrogen fraction ( P <  0.05). Degradation of β-casein could be an indicator of the ripening quality of Krk cheese.     

Flavour enhancement of low-fat Feta-type cheese using a commercial adjunct culture

The effect of a commercial adjunct culture (CR-213), containing Lactococcus lactis subsp. cremoris and Lactococcus lactis subsp.lactis, added at the level of 0.06 or 0.09% (w/w) to cheese milk, on the characteristics of the resultant low-fat Feta-type cheese during aging, was studied. Two controls, a full-fat cheese (∼22% fat) and a low-fat cheese (∼7% fat, made using the standard procedure), were also prepared. The results indicated that the adjunct containing low-fat cheeses exhibited no significant (P>0.05) differences in compositional (moisture, fat, protein, salt, pH) or textural (force and compression to fracture, hardness) characteristics in comparison with the low-fat control cheese. It was also found that the use of the adjunct culture slightly improved the flavour intensity of the low-fat cheese which received a flavour score similar to that of the full-fat control cheese. Moreover, the experimental low-fat cheeses received significantly (P<0.05) higher total scores (overall quality) than the low-fat control cheese but lower than the full-fat cheese.     

Short communication: Norbixin and bixin partitioning in Cheddar cheese and whey

The Cheddar cheese colorant annatto is present in whey and must be removed by bleaching. Chemical bleaching negatively affects the flavor of dried whey ingredients, which has established a need for a better understanding of the primary colorant in annatto, norbixin, along with cheese color alternatives. The objective of this study was to determine norbixin partitioning in cheese and whey from full-fat and fat-free Cheddar cheese and to determine the viability of bixin, the nonpolar form of norbixin, as an alternative Cheddar cheese colorant. Full-fat and fat-free Cheddar cheeses and wheys were manufactured from colored pasteurized milk. Three norbixin (4% wt/vol) levels (7.5, 15, and 30 mL of annatto/454 kg of milk) were used for full-fat Cheddar cheese manufacture, and 1 norbixin level was evaluated in fat-free Cheddar cheese (15 mL of annatto/454 kg of milk). For bixin incorporation, pasteurized whole milk was cooled to 55°C, and then 60 mL of bixin/454 kg of milk (3.8% wt/vol bixin) was added and the milk homogenized (single stage, 8 MPa). Milk with no colorant and milk with norbixin at 15 mL/454 kg of milk were processed analogously as controls. No difference was found between the norbixin partition levels of full-fat and fat-free cheese and whey (cheese mean: 79%, whey: 11.2%). In contrast to norbixin recovery (9.3% in whey, 80% in cheese), 1.3% of added bixin to cheese milk was recovered in the homogenized, unseparated cheese whey, concurrent with higher recoveries of bixin in cheese (94.5%). These results indicate that fat content has no effect on norbixin binding or entrapment in Cheddar cheese and that bixin may be a viable alternative colorant to norbixin in the dairy industry.     

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.     

乳酸菌胞外多糖对低脂Mozzarella奶酪质构、微观结构等品质的影响

目的 研究乳酸菌胞外多糖对低脂Mozzarella奶酪质构等品质特性的影响。方法 在脱除50%乳脂肪的原料中加入0.5%乳酸菌胞外多糖制作低脂Mozzarella奶酪, 同时以全脂Mozzarella奶酪和低脂Mozzarella奶酪为对照, 对Mozzarella奶酪成熟过程中的硬度、弹性、胶黏性、咀嚼性、融化性、油脂析出性、微观结构及感官评分等指标进行分析。结果 0.5%乳酸菌胞外多糖提高了低脂Mozzarella奶酪的水分含量、出品率, 改善了低脂Mozzarella奶酪致密的结构, 形成了类似全脂Mozzarella奶酪疏松、光滑的组织结构, 降低了低脂Mozzarella奶酪的硬度、胶黏性和咀嚼性, 提高了弹性、融化化性和油脂析出, 成熟90 d加入多糖低脂Mozzarella奶酪的滋味和气味、组织状态、色泽接近全脂Mozzarella奶酪。结论 乳酸菌胞外多糖可以提高低脂Mozzarella奶酪的水分含量和出品率, 改善低脂Mozzarella奶酪的组织结构和质构特性。     

Incorporating whey proteins into mozzarella cheese

A study was conducted to improve the yield of cheese and make reduced fat cheese by incorporating whey proteins. Whey protein dispersions were prepared by heating whey at 95°C and pH 4.6, then removing excess serum and homogenizing part of the whey protein. Cheeses were made from standardized milk and standardized milk with homogenized and non-homogenized protein dispersions. Cheeses were also made from standardized milk, reduced fat milk and reduced fat milk with homogenized protein. Adding whey proteins improved the yield, but lowered the retention of fat. Homogenization of whey proteins improved fat retention and yield. The dry matter increase was due to increased solids-non-fat. Reduced fat cheese gave lower yields, which were partially offset by adding homogenized whey proteins. Physical and sensory properties of reduced fat cheeses made with homogenized whey proteins were similar to the control.     

Rheology of Full-fat and Low-fat Cheddar Cheeses as Related to Type of Fat Mimetic

Cheeses with 60% reduced fat were prepared with three fat mimetics and viscoelasticity was studied. Storage and loss moduli of low-fat cheeses made with a carbohydrate-based fat mimetic were greater (p < 0.05) than those of low-fat cheeses made with two protein-based fat mimetics or low-fat control cheese, but smaller (p < 0.05) than the storage and loss moduli of full-fat cheese. A six-element Kelvin model properly predicted the creep compliance for the full-fat cheese and the low-fat cheeses made with or without fat mimetics. Low-fat cheese made with a carbohydrate-based fat mimetic had a network structure more similar to full-fat cheese than the low-fat control or samples made with protein-based fat mimetics.     

Effect of Guar Gum on the Physicochemical, Thermal, Rheological and Textural Properties of Green Edam Cheese

In attempts to produce a low-fat cheese with a rheology and texture similar to that of a full-fat cheese, guar gum (within 0.0025–0.01%; w/v, final concentration) was added to low-fat milk. The obtained cheeses were characterised regarding their physicochemical, thermal, rheological and textural properties. Control cheeses were also produced with low and full-fat milk. The physicochemical properties of the guar gum modified cheeses were similar to those of the low-fat control. No significant differences were detected in the thermal properties (concerning the enthalpy and profile of water desorption) among all types of cheeses. The rheological behaviour of the 0.0025% modified cheese was very similar to the full-fat control. Overall, no trend was observed in the texture profile (hardness, cohesiveness, gumminess and elasticity) of the modified cheeses versus guar gum concentration, as well as in comparison with the control groups, suggesting that none of the studied polysaccharide concentrations simulated the textural functions of fat in Edam cheese.     

Reduction of salt (NaCl) losses during the manufacture of cheddar cheese

The objective of this study was to evaluate the effects of cheese-making technologies, including homogenization of cream, ultrafiltration, and vacuum condensing of milk, on the retention of salt in Cheddar cheese. One part of pasteurized, separated milk (0.58% fat) was ultrafiltered (55 degrees C, 16.0% protein), another vacuum condensed (12.5% protein), and the third was not concentrated. Cheddar cheese was manufactured using 6 treatments by standardizing unconcentrated milk to a casein-to-fat ratio of 0.74 with unhomogenized 35% fat cream (C), homogenized (6.9 MPa/3.5 MPa) 35% fat cream (CH), ultrafiltered milk and unhomogenized cream (UF), ultrafiltered milk and homogenized cream (UFH), condensed milk and unhomogenized cream (CM), and condensed milk and homogenized cream (CMH). Treatments C and CH had 3.7% fat and 3.5% protein, and the respective values for the remaining treatments were 4.9 and 4.6. The milled curd was dry salted at 2.7% by weight. The salt content of the cheeses receiving homogenization treatment was higher at 1.83 and 1.70% for CH and UFH, respectively, compared with their corresponding controls at 1.33%. The salt content in cheeses from CMH was 1.64% and was not affected by homogenization. Salt retention in C increased from 41.7 to 59.2% in CH, and in UF it increased from 42.5 to 54.5% in UFH. There was a corresponding decrease in the salt content of whey from these cheeses.     

Effect of a commercial adjunct culture on organic acid contents of low-fat Feta-type cheese

The effect of a commercial adjunct culture (CR-213, containing Lactococcus lactis subsp. cremoris and Lactococcus lactis susp. lactis and added at the level of 0.6 g kg⁻¹ or 0.9 g kg⁻¹ cheese milk) on the organic acid (OA) content of low-fat Feta-type cheese was studied. Full-fat (∼220 g kg⁻¹) and a low-fat (∼70 g kg⁻¹) cheeses were used as controls. The main OA of all cheeses throughout ripening were lactic, citric and acetic acids. The effect of ripening time was significant (P < 0.05) for all OA but treatments did not affect acetic, succinic and uric acids. Cheeses with lower fat content were found to contain significantly (P < 0.05) more lactic and citric but less butyric acid than the full-fat control. The addition of the adjunct culture had a positive effect on butyric acid, propionic acid and acetoin content. The use of the adjunct culture could enhance the production of OA in low-fat Feta-type cheeses with eventual positive effect on their sensory properties.     

Lipolysis and proteolysis profiles of fresh artisanal goat cheese made with raw milk with 3 different fat contents

The objective of this study was to describe the proteolysis and lipolysis profiles in goat cheese made in the Canary Islands (Spain) using raw milk with 3 different fat contents (0.5, 1.5, and 5%) and ripened for 1, 7, 14, and 28 d. β-Casein was the most abundant protein in all cheeses and at all ripening times. Quantitative analysis showed a general decrease in caseins as ripening progressed, and degradation rates were higher for α_S1-casein than for β-casein and α_S2-casein. Furthermore, the degradation rate during the experimental time decreased with lower fat contents. The α_S2-casein and α_S1-casein levels that remained in full-fat and reduced-fat cheeses were less than those in low-fat cheese. In contrast, β-casein also showed degradation along with ripening, but differences in degradation among the 3 cheese types were not significant at 28 d. The degradation products increased with the ripening time in all cheeses, but they were higher in full-fat cheese than in reduced-fat and low-fat cheeses. The free fatty acid concentration per 100 g of cheese was higher in full-fat cheese than in reduced- and low-fat cheese; however, when the results were expressed as milligrams of free fatty acids per gram of fat in cheese, then lipolysis occurred more rapidly in low-fat cheese than in reduced- and full-fat cheeses. These results may explain the atypical texture and off-flavors found in low-fat goat cheeses, likely the main causes of non-acceptance.     

Flavour-enhancement of low-fat Kashkaval cheese using heat-or freeze-shocked Lactobacillus delbrueckii var. helveticus cultures

Kashkaval cheese of different fat contents was manufactured using heat- or freeze-shocked cultures of Lactobacillus delbrueckii var. helveticus added at a level of 2% to cheese milk prior to renneting. Levels of moisture, total N, salt or titratable acidity of cheeses with different fat levels were different. Proteolysis and lipolysis in low-fat Kashkaval cheese without additives were lower than those found in full-fat cheese. Incorporation of heat- or freeze-shocked L. delbrueckii var. helveticus cultures into milk of low-fat cheese greatly enhanced proteolysis and increased slightly the levels of free fatty acids. Regular low fat cheese did not develop adequate Kashkaval cheese flavour and the cheese was firm. However, addition of heat- or freeze-shocked cultures increased the flavour intensity and improved body and texture of the resultant cheese, yielding low-fat cheese with flavour intensity and body characteristics similar to those of standard fat cheese at each stage of ripening.     

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.     

Effects of fructooligosaccharide and whey protein concentrate on the viability of starter culture in reduced-fat probiotic yogurt during storage

ABSTRACT:  Viability of yogurt starter cultures and Bifidobacterium animalis was assessed during 28 d storage in reduced-fat yogurts containing 1.5% milk fat supplemented with 1.5% fructooligosaccharide or whey protein concentrate. These properties were examined in comparison with control yogurts containing 1.5% and 3% milk fat and no supplement. Although fructooligosaccharide improved the viability of Streptococcus thermophilus , Lactobacillus delbrueckii subs. bulgaricus, and Bifidobacterium animalis , the highest growth was obtained when milk was supplemented with whey protein concentrate in reduced-fat yogurt ( P < 0.05). Supplementation with 1.5% whey protein concentrate in reduced-fat yogurt increased the viable counts of S. thermophilus , L. delbrueckii subs. bulgaricus, and B. animalis by 1 log cycle in the 1st week of storage when compared to control sample. Similar improvement in the growth of both yogurt bacteria and B. animalis was also obtained in the full-fat yogurt containing 3% milk fat and no supplement. Addition of whey protein concentrate also resulted in the highest content of lactic and acetic acids ( P < 0.05). A gradual increase was obtained in organic acid contents during the storage.     

Technological optimization of manufacture of probiotic whey cheese matrices

In attempts to optimize their manufacture, whey cheese matrices obtained via thermal processing of whey (leading to protein precipitation) and inoculated with probiotic cultures were tested. A central composite, face-centered design was followed, so a total of 16 experiments were run using fractional addition of bovine milk to feedstock whey, homogenization time, and storage time of whey cheese as processing parameters. Probiotic whey cheese matrices were inoculated with Lactobacillus casei LAFTIL26 at 10% (v/v), whereas control whey cheese matrices were added with skim milk previously acidified with lactic acid to the same level. All whey cheeses were stored at 7 °C up to 14 d. Chemical and sensory analyses were carried out for all samples, as well as rheological characterization by oscillatory viscometry and textural profiling. As expected, differences were found between control and probiotic matrices: fractional addition of milk and storage time were the factors accounting for the most important effects. Estimation of the best operating parameters was via response surface analysis: milk addition at a rate of 10% to 15% (v/v), and homogenization for 5 min led to the best probiotic whey cheeses in terms of texture and organoleptic properties, whereas the best time for consumption was found to be by 9 d of storage following manufacture.     

The effect of homogenization and milk fat fractions on the functionality of Mozzarella cheese

Mozzarella cheese was manufactured from milk containing either a low (olein) or a high (stearin) melting point fraction of milk fat or anhydrous milk fat. The fat was dispersed into skim milk by homogenization at 2.6 MPa before being manufactured into cheese. The melting point of the milk fat did not affect the size or shape of the fat globules, nor was there any effect of homogenization on the polymorphic state of the milk fat. There were no changes in milk fat globule size and shape concomitant with the amount of free oil formed. The polymorphic state of the milk fat did affect the amount of free oil formed and the apparent viscosity of the cheese. The lower melting point fraction yielded a larger amount of free oil. The higher melting point fraction yielded a higher viscosity of melted cheese at 60 degrees C. Mozzarella cheese was also manufactured from homogenized milk, nonhomogenized milk, and a 1:1 ratio of the two, without altering the milk fat composition. Increasing the proportion of homogenized milk yielded a lower free oil content and higher viscosity of the cheese.     

Influence of defined milk products on the flavour of white coffee beverages using static headspace gas chromatography–mass spectrometry/olfactometry and sensory analysis

The influence of milk processing and ingredients on the sensory properties of white coffee beverages has, as yet, not been thoroughly investigated, so in this study analysed milk products processed in a defined manner were added to a standardized, fresh coffee beverage; the resulting odour, taste and retronasal odour perception were measured by intensity tests, and selected volatiles were analysed by static headspace gas chromatography/mass spectrometry. After adding pasteurized consumers’ milk, the effects of a different fat content (3.5 and 1.5%) and fat dispersion were studied. The milk with the lower fat content and with smaller fat globules, resulting from double homogenization (each 250/50 bar), induced a more intense coffee-related retronasal odour perception, whereas the milk-related impression was nearly the same. The addition of casein increased the creamy and milky retronasal odour perception and reduced the coffee-related taste and retronasal odour. These correlations may result in a custom-made development of milky coffee beverages controlled in their nasal and retronasal odour and taste by the defined processing of the milk component. With instrumental analysis it was observable that the effect of the addition of twice-homogenized, twice-pasteurized low-fat milk and of the addition of whole milk was similar. In both cases more volatiles were released from the beverage than with the addition of low-fat milk that was homogenized once. This is an unexpected result, because the whole milk has a higher fat content than the low-fat milk and therefore a greater retention of the flavour compounds was expected. Is it possible that the flavour compounds are not dissolved in fat and that interactions happen only with fat globule membrane constituents?     

Texture of low-fat Iranian White cheese as influenced by gum tragacanth as a fat replacer

The effect of different concentrations of gum tragacanth on the textural characteristics of low-fat Iranian White cheese was studied during ripening. A batch of full-fat and 5 batches of low-fat Iranian White cheeses with different gum tragacanth concentrations (without gum or with 0.25, 0.5, 0.75, or 1 g of gum/kg of milk) were produced to study the effects of fat content reduction and gum concentration on the textural and functional properties of the product during ripening. Cheese samples were analyzed with respect to chemical, color, and sensory characteristics, rheological parameters (uniaxial compression and small-amplitude oscillatory shear), and microstructure. Reducing the fat content had an adverse effect on cheese yield, sensory characteristics, and the texture of Iranian White cheese, and it increased the instrumental hardness parameters (i.e., fracture stress, elastic modulus, storage modulus, and complex modulus). However, increasing the gum tragacanth concentration reduced the values of instrumental hardness parameters and increased the whiteness of cheese. Although when the gum concentration was increased, the low-fat cheese somewhat resembled its full-fat counterpart, the interaction of the gum concentration with ripening time caused visible undesirable effects on cheese characteristics by the sixth week of ripening. Cheeses with a high gum tragacanth concentration became very soft and their solid texture declined somewhat.