Accelerated Cheddar Cheese Ripening by Added Microbial Enzymes

Good quality medium sharp Cheddar cheeses with 3-mo curing at 10 C were produced when the following enzyme combinations and concentrations were used: fungal protease 31000 (Miles), .005% + fungal lipase-MY (Meito) .00005 to .0002%; and fungal protease P-53 (Rohm & Haas), .0035% + fungal lipase-MY (Meito), .00005 to .0002%.Cheddar cheeses treated with microbial enzymes developed higher soluble protein and free volatile fatty acids and displayed better flavor and greater acceptability than control cheeses. Added microbial proteases contributed to the breakdown of casein, especially β-casein. Also, αs₁-I casein and free amino acids were high in cheeses treated with protease. Increased rate of proteolysis in enzyme-treated cheese had a direct relation to accelerated ripening.     

Rheological Evaluation of Maturing Cheddar Cheese

A number of Cheddar cheese samples of different age, pH and moisture content have been examined rheologically and electrophoretically to determine whether the progressive changes in cheese texture were related to casein proteolysis. The force-compression curves obtained by crushing cubes of cheese between small flat plates at constant speed were different for the different cheese samples and were affected by the moisture content, pH and extent of α_sl-casein proteolysis that had taken place in the cheese. These results support a model of cheese micro structure in which an extensive network involving α_sl- casein molecules traverses the cheese and as the cheese ripens, chymosin cleavage of α_sl-casein weakens the protein network. Such a model explains the rapid decrease in Cheddar cheese yield-force that occurs during the early stages of ripening.     

Reverse-Phase HPLC Analysis of Reference Cheddar Cheese Samples for Assessing Accelerated Cheese Ripening

Applying water extracts from Cheddar cheese to an octadecyl vinyl alcohol copolymer column using a reliable auto-sampling system provided highly repeatable HPLC patterns. Two batches of standard samples of mild, medium, sharp, and extra-sharp and one batch of abused samples (rapidly aged under abnormal conditions) were analyzed. Principal component similarity (PCS) analysis indicated similar shifts of plots due to aging of the standard batches, while the plot for the abused batch deviated from the pathway of normal aging. PCS may be useful for analysis of accelerated ripening effects as well as finding unusual samples during quality control.     

Lactic Acid Bacteria Relation to Accelerated Maturation of Cheddar Cheese

Cheddar cheese was supplemented with cell homogenates and/or live cells of Lactobacillus casei-casei L2A. Two concentrations of cell homogenates under two forms, liquid and lyophilized, were compared as well as two stages of addition, renneting and salting. Growth of lactic acid bacteria and lactobacilli was studied during the period of maturation. Addition of live lactobacilli and lyophilized homogenate at renneting led to a good-quality matured cheese with 40% increase in flavor intensity compared to control cheeses.     

Accelerated Cheddar Cheese Ripening with an Aminopeptidase Fraction from Squid Hepatopancreas

ABSTRACT: An aminopeptidase (AP) fraction from squid (Illex illecebrosus) hepatopancreas was added to Cheddar cheese at 2 levels, and its influence on ripening indices was determined for up to 3-mo storage at 11 °C. Two commercial enzymes (Neutrase ® and Flavourzyme ®) were similarly tested. Cheese with the higher level of squid AP contained more soluble N, amino acids, and Cheddar flavor after 1 mo, but it developed defects in texture and bitterness as ripening progressed. Cheese with less squid AP did not differ from the control with respect to all ripening indices over 3-mo storage. Ripening Cheddar contains cysteine protease inhibitor(s) that inhibit low levels of squid AP but not Neutrase ® and Flavourzyme ®.     

Development of a Rat Model to Test the Nutritional Equivalency of Traditional vs Fabricated Foods: Cheddar Cheese vs Fabricated Cheddar Cheese

Based on the Food & Drug Administration's proposed 1978 standards for “nutritional equivalency,” we have developed a biological assay designed to test the “nutritional equivalency” of traditional vs fabricated foods using cheddar cheese and fabricated cheddar cheese as examples. Diets were formulated that lacked the FDA proposed vitamin and mineral requirements (riboflavin, vitamins B-12 and A, calcium, phosphorus, zinc) for cheese substitutes. By adding traditional or fabricated cheddar cheese to such diets, we were able to compare the overall presence and bioavailability of the vitamins/minerals required for nutritional equivalency. Throughout the 28 day test, the fabricated cheddar cheese did not support the growth of male Sprague-Dawley rats as well as cheddar cheese did.     

Effect of Added Lactobacilli on Composition and Texture of Cheddar Cheese During Accelerated Maturation

The evolution of cheese composition and texture was studied in maturing Cheddar cheese supplemented with live cells and cell homogenates of Lactobacillus casei-casei L2A in order to accelerate maturation. The pH was significantly modified by the lactic acid of the bacterial additives. The Theological properties showed the same general pattern of evolution in experimental as in control cheeses. The process we developed has led to a good-quality matured cheese with 40% increase in flavor intensity compared to control cheeses.     

Nutritional Evaluation of Cheese Spread Powder

A study on the nutritional evaluation of processed cheddar cheese and cheese spread powder made from it, was undertaken. Levels of all constituents, except phosphorus and moisture contents, were significantly higher in cheese spray-dried powder as compared to processed cheese. Biological evaluation of the products showed that a Modified Protein Efficiency Ratio (PER_D), Net Protein Utilization (NPU), and Digestibility Coefficient (DC) and also regeneration of certain organs, in protein depleted albino rats fed diets based on processed cheese and spray-dired powder made from it, were identical.     

Salt Diffusion in Cheddar Cheese

Salt changes in Cheddar cheese made intentionally with poor salt distribution and in model systems have been determined. Salt equilibrium was not attained within blocks of Cheddar cheese during 24 wk ripening. Diffusion of salt from milled salted curd into unsalted curd in a model system likewise was very slow with a steep salt gradient still existing after 56 d.In contrast, salt diffusion in 2 × 2 × 6-cm pieces of Cheddar curd was rapid with equilibration in about 48 h. Also, salt diffusion into unsalted discs (7.4 diameter by 2 cm thick) of curd from salted discs of curd was rapid.Brine salting of Cheddar cheese showed that the diffusion coefficient was directly related to moisture content and was consistent with those obtained in other cheeses.Reasons for a slow rate of salt equilibration in nonbrine-salted Cheddar cheese are proposed.     

Cheddar Cheese from Water Reconstituted Retentates

Reconstituted creamed retentates of ultrafiltration were converted to ripened cheese by Cheddar manufacturing principles. Initially, the fresh cheeses resembled normal Cheddar but during ripening were transformed into Gouda-Swiss types with pH rising rapidly from 5.2 to approximately 6.0.Cheese composition was affected by amount of full fat retentate in reconstituted mixtures. As total milk solids increased in reconstituted retentates, cheese moisture decreased and cheese volume rose to high yields. Cheese yield efficiency showed 1.21 to 1.32 kg cheese per kg total solids. Rennet curd of higher total solids retentates formed more rapidly than normal, and curds were harder. Whey from retentate reconstituted cheeses showed relatively low ash and fat even from cheeses made with high retentate. Soluble protein in 2-mo-old cheeses held at 10° C was lower in cheese from retentates of high solids.     

Calcium Bioavailability from Ripening Cheddar Cheese

Calcium bioavailability to rats was compared from CaCl₂ (28 mM), CaCO₃, fresh milk, milk adjusted to pH 5.35, and Cheddar cheese. The cheese was manufactured from pasteurized bovine milk and all doses were labeled extrinsically with ⁴⁵Ca and ⁴⁷Ca and administered orally to rats. One label (⁴⁵Ca) was added to milk before cheese manufacture and the other (⁴⁷Ca) was added to the cheese 24 h prior to dosing. Calcium bioavailability was determined by: 1) absorption measured by whole body counting, and 2) availability for bone metabolism assessed by bone radioactivity measurements. Calcium absorption averaged 76.8% and was not affected by length of ripening (p>0.05). Absorption from CaCl₂, CaCO₃, fresh milk, milk at pH 5.35, and the cheeses was similar. The two methods gave similar estimates of relative bioavailability. The ratio of ⁴⁷Ca absorption to ⁴⁵Ca absorption for any cheese sample was significantly greater than 1, indicating extrinsic labels added after processing may overestimate Ca absorption from cheese.     

Fat Mimetics in Low-Fat Cheddar Cheese

Cheeses with 60% reduced fat content were prepared with three commercial fat mimetics. Low-fat cheeses without added fat mimetics and full-fat cheeses were prepared as controls. Cheeses were aged 3 months prior to sensory and instrumental evaluation. A low-fat cheese containing one of the fat mimetics received the highest texture scores from dairy judges and consumer panelists (P≤0.05). The low-fat control and another cheese with a fat mimetic received higher flavor scores from the trained dairy judges and consumer panelists than the other cheeses containing fat mimetics (P≤0.05). Low-fat cheeses containing fat mimetics were less rubbery than the low-fat control cheese (P≤0.05).     

Nutritional Evaluation of Typical and Reformulated Italian Cheese

The aim of this work was the nutritional evaluation of reformulated dairy products (caciotta-type cheese) and manufactured either with a low-sodium chloride content (different salting time and/or composition of the brine) or low-fat content (different partially skimmed milks). These cheeses were intended for people on low-energy or low-sodium diets. A comparison was made between these new products and three typical Italian cheeses (Provolone, Taleggio and Pecorino Romano). The nutrient content of the products was determined. Amino acids by chromatographic methods, protein digestibility by an enzymatic method and lysine availability determined spectrophotometrically were shown not to be influenced by the salt reduction. The salt reduction also did not affect vitamin contents (riboflavin, retinols, carotenes and tocopherols) measured by HPLC methods, while the reduced fat contents (310 g kg^-1, 160 g kg^-1 and 87 g kg^-1) led to significant decreases in concentrations of fat-soluble vitamins (38% for tocopherols and 7% for total retinols) and a decrease in riboflavin (13%) due to the loss of riboflavin enzymes located on the fat globules (ie xanthine oxidase). Both the typical cheeses and the new formulations represent good sources of calcium and protein. Protein digestibility was affected by the ripening time; in fact, in Pecorino Romano, ripened for 6–9 months it reached 62% in 6 h, whereas in Taleggio and in all caciotta–cheeses it reached only 32–37%. The nutritional profiles of the reformulated caciotta cheese showed that these products could represent a good choice in low-energy and low-sodium diets, but an enrichment of fat-soluble vitamins is advisable in the low-fat products. © 1997 SCI.     

Nutritional Evaluation of Cereal–Cheese Whey Mixtures

The chemical composition, amino acid content, PER, and digestibility of dehydrated sweet cheese whey, wheat flour, wheat bran, and lime-treated corn flour (nixtamal, used for making tortillas), as well as of 21 cereal-cheese whey mixtures were determined. The cheese whey was composed of 12% protein and 74% lactose. Diets containing a total of 8% protein were formulated with the cereal-cheese whey mixtures. The 50:50 (% protein) cereal-whey mixtures had the highest adjusted modified PERs, representing an increase over the cereals alone of 324% for the corn flour, 215% for wheat flour, and 177% for wheat flour, and 177% for wheat bran. The 50:50 (% protein) wheat bran mixture had the largest adjusted modified PER at 2.33 ± 0.13 (mean ± SEM) and the 50:50 wheat flour mixture, the smallest at 1.48 ± 0.21. Although the apparent digestibility was reduced from 10–14% for the latter two 50:50 cereal-whey mixtures compared to the cereals alone, this was not reflected in the PER. It was concluded that the nutritive value of all the cereals tested significantly increased with the addition of 155 25% or more (by weight) of dehydrated cheese whey.     

Accelerated Maturation of Cheddar Cheese: Influence of Added Lactobacilli and Commercial Protease on Composition and Texture

The addition of live and heat-shocked Lactobacillus casei-casei L2A and Neutrase© was tested for its ability to accelerate the maturation of Cheddar cheese. An evaluation of physicochemical and rheological properties showed that cheese pH was decreased by bacterial and enzymatic additives, while fracturability and cohesiveness were influenced principally by Neutrase. The integrated process recommended is composed of three parts: first, the addition of live L. casei-casei L2A to control the undesirable microflora, second, heat-shocked cells of the same species at a concentration of 1.0%, and third, Neutrase at a concentration not higher than 1.0 × 10^-5 AU/g of cheese. This process led to a good-quality sharp Cheddar cheese with 60% increase in flavor intensity compared to control cheese.     

儿童型香蕉果肉再制干酪的研制

再制干酪是我国干酪市场中的主要消费品种,但果肉型再制干酪较为少见。开发儿童型果肉干酪可以满足儿童营养需要和喜好,而且对于丰富再制干酪食品的品种、提高干酪中的食用纤维和其它营养素具有重要意义。试验以自制天然干酪、香蕉果浆为主要原料,采用三种工艺流程,通过L_9(3~4)正交试验确定最适工艺流程及最佳配方为:天然干酪,水(45%)、乳化盐(2．5%)、白砂糖(7%)、黄原胶(0．5%)混合融化7min后,加入香蕉果浆(30%),继续混合5min,迅速冷却到4℃。以此工艺制得的香蕉口味再制干酪,不仅可以保持传统再制干酪一定的风味及组织状态,并具有香蕉固有的营养与香味。     

Cheddar Cheese from Ultrafiltered Whole Milk Retentates in Industrial Cheese Making

Transporting whole milk retentates of ultrafiltration to a distant large industrial Cheddar cheese making site resulted in 16 lots of Cheddar cheese from vats containing 2,546 to 16,360 kg of cheese milk. Whole milk retentates concentrated by ultrafiltration to 4.5:1 were added to cheese milks to give mixtures concentrated 1.2:1 and 1.3:1 with approximately 20 and 30% more protein and fat, respectively, than in unsupplemented control whole milks or unsupplemented commercial reference milks.Gross composition of Cheddar cheese made from commercial reference, control, and retentate-supplemented milk generally showed no major differences. Yield increased in cheese made from retentate-supplemented milk. Yield efficiency per kilogram total solids rose in retentate cheese over controls but not among commercial reference, control, and retentate lots based on per kilogram fat or total protein. Milk components were higher in wheys from retentate cheeses, but loss of components per kilogram cheese obtained generally showed lower values in whey from retentate cheese.General quality of retentate Cheddar cheese was equal to that of reference unsupplemented commercial cheese and higher than unsupplemented control Cheddar cheeses. It appears technically feasible to ultrafilter milk at one site, such as the farm, collecting station, or specialized center, and transport it to an industrial site for Cheddar cheese making.