ORGANIC ACID CONTENTS OF BUFFALO MILK CHEDDAR CHEESE AS INFLUENCED BY ACCELERATED RIPENING AND SODIUM SALT

Effect of fat contents of buttermilk on fatty acid composition, lipolysis, vitamins and sensory properties of cheddar-type cheese

Cheddar-type cheese produced from buttermilk had softer texture than standard cheddar cheese due to lower fat content of buttermilk. Fat is extremely important for the functional characteristics and optimum textural attributes of cheese. The effect of different fat contents of buttermilk on chemical characteristics of cheddar-type cheese is not previously investigated. This investigation was conducted to know the effect of different fat contents of buttermilk on fatty acids composition, organic acids, vitamins, lipolysis and sensory characteristics of cheddar-type cheese. Cheddar-type cheese was produced from buttermilk having 1, 1.75, 2.50 and 3.25% fat contents (control, T1, T2 and T3). Fat content of control, T1, T2 and T3 were 9.81, 16.34, 25.17 and 31.19%. Fatty acids profile was determined on GC-MS, organic acids and vitamin A and E were determined on HPLC. Free fatty acids, peroxide value and cholesterol were determined. Cheddar-style cheese produced from buttermilk (1% fat) showed that it had softer texture and lacking typical cheese flavor. Gas chromatography-mass spectrometry (GC-MS) analysis showed that long-chain unsaturated fatty acids in control, T1, T2 and T3 samples were 45.88, 45.78, 45.90 and 46.19 mg/100 g. High Performance Liquid Chromatography (HPLC) analysis showed that lactic acid, propionic acid, citric acid and acetic acid gradually and steadily increased during the storage interval of 90 days. At the age of 90 days, lactic acid in control, T1, T2 and T3 was 4,789, 5,487, 6,571 and 8,049 ppm, respectively. At the end of ripening duration of 90 days, free fatty acids in control, T1, T2 and T3 were 0.29, 0.31, 0.35 and 0.42% with no difference in peroxide value. Stability of vitamin A after 90 days storage control, T1, T2 and T3 was 87.0, 80.0, 94.0 and 91.0%. Flavor score of cheddar-type cheese produced from butter milk having 1.0, 2.5 and 3.25% fat content was 81, 89 and 91% of total score (9). Hence, it is concluded that cheddar-type cheese can be produced from buttermilk having 2.5 and 3.25% fat contents with acceptable sensory attributes. Application of buttermilk for the production of other cheese varieties should be studied.

Effect of Inulin on Organic Acids and Microstructure of Synbiotic Cheddar-Type Cheese Made from Buffalo Milk

The current study aimed to produce synbiotic cheese, adding inulin and Bifidobacterium animalis subsp. lactis as prebiotics and probiotics, respectively. The physicochemical analysis, minerals and organic acids content, sensory evaluation, and probiotic count of the cheese were performed during the ripening. The significant effect of inulin (p ≤ 0.01) was found during the ripening period, and changes in physiochemical composition, minerals, and organic acid contents were also observed. Scanning electron microscopy (SEM) of the cheese revealed that inulin could improve the cheese structure. Meanwhile, inulin increased the likeliness of the cheese, and its probiotic viability remained above 10⁷ colony forming unit (CFU) per gram during ripening.

Physicochemical and textural characteristics and volatile compounds of semihard goat cheese as affected by starter cultures

Today, cheese is valued because of its high nutritional value and unique characteristics. Improving the texture and flavor of cheese by selecting suitable starter cultures is an important way to promote the development of cheese industry. The effect of starter cultures on the physicochemical and textural properties and volatile compounds during the ripening of semihard goat cheese were investigated in this work. Different starter cultures-mesophilic (M) and thermophilic starters (T), Lactobacillus plantarum ssp. plantarum ATCC 14917 (Lp), a mix of the M and T starters (M1), and mix of the M, T, and Lp starters (M2)-were used in the production of the goat cheeses. Volatile compounds were determined by a solid-phase microextraction/gas chromatography-mass spectrometric (SPME/GC-MS) method. The results showed that the moisture content of cheeses produced with the 5 kinds of starter cultures decreased after maturation, whereas ash content increased. The pH values of goat cheeses decreased first and then increased during maturity, and the pH value of M2 cheese was the lowest among the cheeses. The hardness and chewiness of the cheeses increased with increasing maturity, whereas cohesiveness, springiness, and resilience showed the opposite tendency. The 60-d-old cheese made with Lp had the highest chewiness, cohesiveness, springiness, and resilience, whereas the 60-d-old cheese made with M2 had the highest hardness. A total of 53 volatile components were identified by SPME/GC-MS, and carboxylic acids, alcohols, ketones, and esters were the 4 major contributors to the characteristic flavors of the cheeses. Volatile components and their contents differed greatly among the produced cheeses. The M2 cheese contained the highest relative content of the main volatile compounds (90.10%), especially butanoic acid and acetoin. Through a comprehensive comparison of the results, we concluded that M2 cheese had a dense texture and milky flavor, and M2 is a potential starter culture candidate for the production of goat cheese.

Lipolysis and antioxidant properties of cow and buffalo cheddar cheese in accelerated ripening

BACKGROUND

Buffalo milk is the second largest source of milk on the globe, it is highly suitable for the preparation of mozzarella cheese, however, it is not suitable for the preparation of cheddar cheese due to high buffering capacity, low acid development, excessive syneresis, lower lipolysis that lead to lower sensory score. Accelerated ripening can enhance lipolysis and improve sensory characteristics of cheddar cheese. Lipolysis and antioxidant capacity of buffalo cheddar cheese in conventional ripening is not previously studied. Optimization of ripening conditions can lead to better utilization of buffalo milk in cheese industry.

METHODS

Effect of accelerated ripening on lipolysis and antioxidant properties of cow and buffalo cheddar cheese were investigated. Cheddar cheese prepared from standardized (3.5% fat) cow and buffalo milk was subjected to conventional and accelerated ripening (4 °C and 12 °C) for a period of 120 days. Fatty acid profile, organic acids, free fatty acids, cholesterol, antioxidant activity and sensory characteristics were studied at 0, 40, 80 and 120 days of ripening.

RESULTS

Fatty acid profile of cow and buffalo cheddar in conventional (120 days old) and accelerated ripening were different from each other (p < 0.05). Free fatty acids in 120 days old buffalo and control cheddar, in accelerated ripening were 0.55% and 0.62%. After accelerated ripening, cholesterol in buffalo and control cheddars were 16 and 72 mg/100 g. After accelerated ripening, concentrations of formic, pyruvic, lactic, acetic and citric acids in buffalo cheddar cheese were, 922, 136, 19,200, 468 and 2845 ppm. At the end of accelerated ripening (120 days), concentrations of formic, pyruvic, lactic, acetic and citric acids in cow cheddar cheese were 578, 95, 9600, 347 and 1015 ppm. Total antioxidant capacity of control cow and buffalo cheddar in accelerated ripening was 77.26 and 88.30%. Colour, flavour and texture score of rapid ripened 80 and 120 days old buffalo cheddar was not different from cow cheddar.

CONCLUSIONS

Results of this investigations showed that flavour profile buffalo cheddar subjected to accelerate ripening was similar to cow cheddar cheese. Accelerated ripening can be used for better utilization of buffalo milk in cheddar cheese industry.

Impact of vitamin E and selenium on antioxidant capacity and lipid oxidation of cheddar cheese in accelerated ripening

Background

Ripening of cheddar cheese is a time taking process, duration of the ripening may be as long as one year. Long ripening time is a big hindrance in the popularity of cheese in developing countries. Further, energy resources in these countries are either insufficient or very expensive. Therefore, those methods of cheese ripening should be discovered which can significantly reduce the ripening time without compromising the quality characteristics of cheddar cheese. In accelerated ripening, cheese is usually ripened at higher temperature than traditional ripening temperatures. Ripening of cheddar cheese at high temperature with the addition of vitamin E and selenium is not previously studied. This investigation aimed to study the antioxidant activity of selenium and vitamin E in accelerated ripening using cheddar cheese as an oxidation substrate.

Methods

The ripening of cheddar cheese was performed at 18 °C and to prevent lipid oxidation, vitamin E and selenium were used alone and in combination. The treatments were as: cheddar cheese without any addition of vitamin E and selenium (T1), cheddar cheese added with 100 mg/kg vitamin E (T₂), 200 mg/kg vitamin E (T₃), 800 μg/kg selenium (T₄), 1200 μg/kg selenium (T₅), vitamin E 100 mg/kg + 800 μg/kg selenium (T₆) and vitamin E 200 mg/kg + 1200 μg/kg selenium (T₇). Traditional cheddar cheese ripne ripened at 4-6 °C for 9 months was used as positive control. Cheese samples were ripened at 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 6 and 12 weeks of storage. All these treatments were compared with a cheddar cheese without vitamin E, selenium and ripened at 4 °C or 12 weeks. Vacuum packaged cheddar cheese was ripened 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 4 and 8 weeks of storage period.

Results

Addition of Vitamin E and selenium did not have any effect on moisture, fat and protein content of cheddar cheese. After 6 weeks of ripening, total antioxidant capacity of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese were 29.61%, 44.7%, 53.6%, 42.5%, 41.4%, 64.1%, 85.1% and 25.4%. After 6 weeks of ripening, reducing power of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and SC cheese were 14.7%, 18.1%, 26.3%, 19.2%, 25.3%, 33.4%, 40.3% and 11.6%. After 6 weeks of ripening, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of T₆ and T₇ were 54.2% and 66.9%. While, DPPH free radical scavenging activity of T₁ and standard cheese after 6 weeks of ripening were, 19.1 and 18.5%, respectively. Free fatty acids of vitamin E and selenium supplemented, non-supplemented and standard cheese were not significantly influenced from each other in 0, 6 and 12 weeks old cheddar cheese. Peroxide values of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese after 6 weeks of accelerated ripening were 1.19, 1.05, 0.88, 1.25, 0.29, 0.25, 0.24 and 0.28 (MeqO₂/kg). After 6 weeks of ripening, anisidine value of T₆ and T₇ were 6.55 and 6.14. Conjugated dienes of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese, after 6 weeks of accelerated ripening were 0.61, 0.55, 0.42, 0.77, 0.65, 0.17, 0.15 and 0.19. After 6 weeks of accelerated ripening, concentrations unsaturated fatty acids in T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese decreased by18.19%, 17.45%, 16.82%, 16.19%, 12.71%, 8.48%, 6.92% and 14.71%. After 12 weeks of accelerated ripening, concentration of unsaturated fatty acids in T₁, T₂, T₃, T₄, T₅, T₆ and T₇ and standard cheese decreased by 26.2%, 21.2%, 18.7%, 14.2%, 10.4%, 4.84%, 1.03% and 6.78%. Cheddar cheese samples added with vitamin E, selenium and their combinations produced more organic acids during the ripening period of 12 weeks. After 6 and 12 weeks of ripening, flavor score of T₆ and T₇ was better than standard ripened cheddar cheese.

Conclusions

After 6 weeks of accelerated ripening, sensory characteristics of T₆ and T₇ were similar to cheddar cheese that was ripened at 4 °C for 9 months. Ripening time of cheddar cheese may be reduced to 6 weeks by elevated temperature (18 °C) using vitamin E and selenium as antioxidants at T₆ and T₇ levels.

Invited review: Bioactive compounds produced during cheese ripening and health effects associated with aged cheese consumption

Traditionally, cheese is manufactured by converting fluid milk to a semisolid mass through the use of a coagulating agent, such as rennet, acid, heat plus acid, or a combination thereof. Cheese can vary widely in its characteristics, including color, aroma, texture, flavor, and firmness, which can generally be attributed to the production technology, source of the milk, moisture content, and length of aging, in addition to the presence of specific molds, yeast, and bacteria. Among the most important bacteria, lactic acid bacteria (LAB) play a critical role during the cheese-making process. In general, LAB contain cell-envelope proteinases that contribute to the proteolysis of cheese proteins, breaking them down into oligopeptides that can be subsequently taken up by cells via specific peptide transport systems or further degraded into shorter peptides and amino acids through the collaborative action of various intracellular peptidases. Such peptides, amino acids, and their derivatives contribute to the development of texture and flavor in the final cheese. In vitro and in vivo assays have demonstrated that specific sequences of released peptides exhibit biological properties including antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, and analgesic/opioid activity, in addition to angiotensin-converting enzyme inhibition and antiproliferative activity. Some LAB also produce functional lipids (e.g., conjugated linoleic acid) with anti-inflammatory and anticarcinogenic activity, synthesize vitamins and antimicrobial peptides (bacteriocins), or release γ-aminobutyric acid, a nonprotein amino acid that participates in physiological functions, such as neurotransmission and hypotension induction, with diuretic effects. This review provides an overview of the main bioactive components present or released during the ripening process of different types of cheese.

The effect of sodium reduction with and without potassium chloride on the survival of Listeria monocytogenes in Cheddar cheese

Sodium chloride (NaCl) in cheese contributes to flavor and texture directly and by its effect on microbial and enzymatic activity. The salt-to-moisture ratio (S/M) is used to gauge if conditions for producing good-quality cheese have been met. Reductions in salt that deviate from the ideal S/M range could result in changing culture acidification profiles during cheese making. Lactococcus lactis ssp. lactis or Lc. lactis ssp. cremoris are both used as cultures in Cheddar cheese manufacture, but Lc. lactis ssp. lactis has a higher salt and pH tolerance than Lc. lactis ssp. cremoris. Both salt and pH are used to control growth and survival of Listeria monocytogenes and salts such as KCl are commonly used to replace the effects of NaCl in food when NaCl is reduced. The objectives of this project were to determine the effects of sodium reduction, KCl use, and the subspecies of Lc. lactis used on L. monocytogenes survival in stirred-curd Cheddar cheese. Cheese was manufactured with either Lc. lactis ssp. lactis or Lc. lactis ssp. cremoris. At the salting step, curd was divided and salted with a concentration targeted to produce a final cheese with 600 mg of sodium/100 g (control), 25% reduced sodium (450 mg of sodium/100 g; both with and without KCl), and low sodium (53% sodium reduction or 280 mg of sodium/100 g; both with and without KCl). Potassium chloride was added on a molar equivalent to the NaCl it replaced to maintain an equivalent S/M. Cheese was inoculated with a 5-strain cocktail of L. monocytogenes at different times during aging to simulate postprocessing contamination, and counts were monitored over 27 or 50 d, depending on incubation temperature (12 or 5 °C, respectively). In cheese inoculated with 4 log₁₀ cfu of L. monocytogenes/g 2 wk after manufacture, viable counts declined by more than 3 log₁₀ cfu/g in all treatments over 60 d. When inoculated with 5 log₁₀ cfu/g at 3mo of cheese age, L. monocytogenes counts in Cheddar cheese were also reduced during storage, but by less than 1.5 log10 cfu/g after 50 d. However, cheese with a 50% reduction in sodium without KCl had higher counts than full-sodium cheese at the end of 50 d of incubation at 4 °C when inoculated at 3 mo. When inoculated at 8 mo postmanufacture, this trend was only observed in 50% reduced sodium with KCl, for cheese manufactured with both cultures. This enhanced survival for 50% reduced-sodium cheese was not seen when a higher incubation temperature (12 °C) was used when cheese was inoculated at 3 mo of age and monitored for 27 d (no difference in treatments was observed at this incubation temperature). In the event of postprocessing contamination during later stages of ripening, L. monocytogenes was capable of survival in Cheddar cheese regardless of which culture was used, whether or not sodium had been reduced by as much as 50% from standard concentrations, or if KCl had been added to maintain the effective S/M of full-sodium Cheddar cheese.