UF-Feta Cheese Research Articles

Effects of free and encapsulated Siah-e-Samarghandi grape seed extract on the physicochemical, textural, microbial, and sensorial properties of UF-Feta cheese.

The current study was conducted to elucidate the impact of grape seed extract (SE) and microencapsulated seed extract (MSE) addition to UF-Feta cheese. The SE was encapsulated in maize starch, alginate, and canola oil using the emulsion technique. The SE and MSE characteristics were evaluated. The products were subjected to physicochemical (pH, titrable acidity, color, texture, and sensory properties), microbiological analysis (starter count), and lipid oxidation test (proxide, acid degree, and ansidine value) during 60 days of storage. The main phenol component in the SE was catechin (419.04 mg/L), gallic acid (319.63 mg/L), and chlorogenic acid (4.19 ± 0.002 mg/L). The antioxidant value was 157.80 mg/L. The MSE was elliptical in shape with a 24.29 μm diameter. The efficiency of microencapsulation was 53.86%. The addition of SE and MSE had no significant effect on pH and acidity, but lipolysis decreased based on acid degree value (0.7%; p > .05). The increasing trend of peroxide values was 172.54%, 145.68%, and 118.75% for C, SE, and MSE samples, respectively, and 35.68%, 32.28%, and 17.24% for the P-anisidine values during the storage time. Therefore, fat oxidation was reduced in the supplemented cheese. Nevertheless, the supplemented cheese had limited color alterations. The MSE and SE did not affect the survival rates of the starter count. The SE and MSE had a less rigid structure. The hardness (2748.0 g) and chewiness (57.45 mJ) values in SE cheese had the greatest value among the samples. All sensory parameters were lowest in MSE cheese. In short, encapsulation showed suitable properties for SE to apply in UF-Feta cheese.

COMPARISON OF ANTIFUNGAL PROPERTIES OF LACTOBACILLUS RHAMNOSUS AND LACTOBACILLUS REUTERI WITH POTASSIUM SORBATE IN THE IRANIAN UF-FETA CHEESE

This study was aimed to compare antifungal properties of two lactobacilli strains with potassium sorbate in cheese. In this regard, the effect of 10-fold cell-free extract of Lactobacillus rhamnosus РТСС 1637 and Lactobacillus reuteri РТСС 1655 was studied on the growth of mold and yeast in the Iranian UF-Feta Cheese during a 60-day ripening period at 4 ℃. Additionally, the antifungal effect of potassium sorbate (300 and 500 ppm) and mixture of potassium sorbate and cell-free extract of tested bacteria were evaluated. The results showed that yeast and mold growth was occurred in both control and treated chesses, however, after 30 days storage, mold and yeast count was significantly lower in the cell free supernatant-treated UF-Feta cheese in comparison to the control cheese. Addition of potassium sorbate, as expected, significantly reduced mold and yeast growth in UF-Feta cheese during ripening period than control. On the other hand the result showed that mixture of probiotic extract and potassium sorbate had more efficiency in mold and yeast growth reduction than when the sorbate potassium was used alone. The highest fungal growth inhibition was achieved by application of 2 mL cell-free extract of L. reuteri CCTP 1655 along with 500 ppm potassium sorbate. Generally, it could be concluded that cell-free supernatant of tested bacteria has potential for use as bio preservatives in cheese and although studied probiotic extracts are not as effective as sorbate potassium in preventing fungi and yeast growth, they can be useful in reduction of yeast and mold growth.

COMPARISON OF ANTIFUNGAL PROPERTIES OF LACTOBACILLUS RHAMNOSUS AND LACTOBACILLUS REUTERI WITH POTASSIUM SORBATE IN THE IRANIAN UF-FETA CHEESE

This study was aimed to compare antifungal properties of two lactobacilli strains with potassium sorbate in cheese. In this regard, the effect of 10-fold cell-free extract of Lactobacillus rhamnosus РТСС 1637 and Lactobacillus reuteri РТСС 1655 was studied on the growth of mold and yeast in the Iranian UF-Feta Cheese during a 60-day ripening period at 4 ℃. Additionally, the antifungal effect of potassium sorbate (300 and 500 ppm) and mixture of potassium sorbate and cell-free extract of tested bacteria were evaluated. The results showed that yeast and mold growth was occurred in both control and treated chesses, however, after 30 days storage, mold and yeast count was significantly lower in the cell free supernatant-treated UF-Feta cheese in comparison to the control cheese. Addition of potassium sorbate, as expected, significantly reduced mold and yeast growth in UF-Feta cheese during ripening period than control. On the other hand the result showed that mixture of probiotic extract and potassium sorbate had more efficiency in mold and yeast growth reduction than when the sorbate potassium was used alone. The highest fungal growth inhibition was achieved by application of 2 mL cell-free extract of L. reuteri CCTP 1655 along with 500 ppm potassium sorbate. Generally, it could be concluded that cell-free supernatant of tested bacteria has potential for use as bio preservatives in cheese and although studied probiotic extracts are not as effective as sorbate potassium in preventing fungi and yeast growth, they can be useful in reduction of yeast and mold growth.

Development and characterization of probiotic UF Feta cheese containing Lactobacillus paracasei microencapsulated by enzyme based gelation method.

In this study probiotic microcapsules with three different shell compositions were produced through enzymatic gelation of skim milk powder by rennet, skim milk powder by transglutaminase and sodium caseinate by transglutaminase. Fabricated microcapsules and free Lactobacillus paracasei cells were incorporated into Iranian UF Feta cheese with different salt levels. Viability of L. paracasei (LAFTI L26), antioxidative capacity, ripening index, titrable acidity, salt content and texture profile analysis (TPA test) parameters including hardness, cohesiveness and stringiness were monitored during 45days of storage time. Rennet based encapsulation was the most efficient method and could keep L. paracasei viable in all cheese samples (> 7log10CFU/g) at the end of storage time. Proteolysis pattern and acidification rate were strongly influenced by shell composition, salt level and storage time. Hardness and stringiness of probiotic cheese samples were influenced by shell composition of microcapsules and storage time but cohesiveness was only dependent on storage time. Therefore, storage time was the only effective factor on free radical scavenging activity of cheese samples.

Effect of enzymatic transglutaminase treatment on textural and sensory properties of low-fat UF-Feta cheese incorporated with whey proteins using response surface optimization.

شواهد علمی نشان داده است که مصرف چربی ارتباط مستقیمی با بیماری های مختلفی از جمله چاقی، دیابت، سفت شدن دیواره رگ ها و فشار خون دارد. به همین دلیل طی سال های اخیر تقاضا برای محصولات کم‌چرب افزایش چشمگیری پیدا کرده است. پنیر به‌عنوان یک فراورده لبنی با ارزش نقش پررنگی در رژیم غذایی جامعه دارد. با این حال این فراورده حاوی مقادیر بالایی از چربی می باشد که سبب ایجاد نگرانی های از جانب مصرف‌کنندگان شده است. در این پژوهش از روش سطح پاسخ به‌منظور مطالعه اثر آنزیم ترانس گلوتامیناز (2-0 واحد به ازای هرگرم پروتئین)، محلول کنسانتره پروتئینی آب پنیر یا WPC (16-0 درصد) و سطوح چربی (10-0 درصد) بر خواص کیفی و بهینه‌سازی فرمولاسیون پنیر فراپالایش کم‌چرب استفاده گردید. نتایج نشان داد که کاهش چربی باعث افزایش معنی‌دار سفتی، ارتجاع‌پذیری و میزان رطوبت می شود اما چسبندگی و امتیاز پذیرش کلی نمونه های پنیر کاهش می یابد. برخلاف WPC، تیمار آنزیمی با ترانس گلوتامیناز سفتی، پیوستگی و ارتجاع‌پذیری را بطور معنی‌داری افزایش داد اما میزان رطوبت و چسبندگی پنیر را کاهش داد. در این میان آنزیم ترانس گلوتامیناز اثر معنی‌داری بر امتیاز کلی ارزیابی حسی نداشت اما خواص حسی نمونه‌های پنیر کم‌چرب با جایگزینی WPC با ناتراوه تا میزان 8% بهبود یافت. نتایج بهینه‌سازی با طرح مرکب مرکزی نشان داد که بهترین نمونه با خواص حسی و بافتی مطلوب زمانی حاصل می‌شود که فرمول پنیر شامل 95/5% چربی، 56/0 واحد آنزیم ترانس گلوتامیناز و 79/8% محلول WPC باشد.

RETRACTED: Enhancing the lipolysis of feta-type cheese made from ultrafiltered cow's milk

Abstract This study was conducted to investigate the effects of adding different levels of commercial pregastric lipase enzyme (calf lipase) on the free fatty acid profile of ultrafiltered Feta type cheese during ripening period. With an increase in added lipase level and ripening period, the main components of cheese including total solids, fat, fat in total solids, salt and salt in total solids did not change significantly but water soluble nitrogen increased. Increasing the added pregastric lipase level resulted in a significant decrease in the percentages of C 4:0 -C 8:0 free fatty acids while that of C 12:0 -C 18:0 and C 18:1 free fatty acids increased. According to sensory analysis of cheese samples, the best samples had the combination of 20, 40 and 60 days of ripening with 6 g/100 kg, 4 g/100 kg and 2 g/100 kg lipase in retentate, respectively. The addition of lipase to cheese milk could be recommended for the acceleration of flavor development and ripening of UF-Feta cheese over a short ripening period.

Sodium benzoate and potassium sorbate preservatives in food stuffs in Iran

A high-performance liquid chromatography method was applied for the determination of the levels of benzoate and sorbate in 400 food samples, including pickled cucumbers, canned tomato pastes, sour cherry jams, soft drinks, fruit juices and dairy products (UF-Feta cheeses, Lighvan cheeses, lactic cheeses, yogurts and doogh). The results showed that 270 (67.5%) of all samples contained benzoate ranging from 11.9 to 288.5 mg kg−1 in lactic cheese and fruit juice, respectively. The levels of sorbate in 98 (24.5%) of the samples were 20.1 to 284.3 mg kg−1 in doogh and fruit juice, respectively. Moreover, benzoate was detected in all dairy products ranging from 11.9 mg kg−1 in lactic cheese to 91.2 mg kg−1 in UF-Feta cheese. A low concentration of benzoate could originate naturally, due to specific biochemical mechanisms during cheese, yogurt and doogh maturation. In conclusion, a minimum level for benzoate in dairy products should be defined in the legislation.

Chemical, proteolysis and sensory attributes, and probiotic microorganisms viability of Iranian ultrafiltered-Feta cheese as a function of inulin concentration and storage temperature

The aim of the present work was to study the effects of inulin addition (0, 1.5 and 3% w/w) and the storage temperature (8 and 12 °C) on the viability of probiotic organisms (Lactobacillus acidophilus la-5 and Bifidobacterium lactis BB-12), chemical composition, proteolysis and sensory characteristics of ultrafiltered (UF)-Feta cheeses over 60 days storage time. Storage time was the most effective factor on dependent variables. Population of both strains remained above 106 cfu/g at the end of storage time and their viability was neither significantly affected by the inulin concentration, nor by the storage temperatures. No significant (P>0.05) differences were observed in sensory scores, syneresis, water soluble nitrogen, trichloroacetic acid soluble nitrogen and other physicochemical properties (except for dry matter) among different cheese samples at different temperatures. The levels of flavour, odour and overall acceptability were significantly increased as storage period progressed. The results suggest UF-Feta cheese is a suitable carrier for L. acidophilus la-5 and B. lactis BB-12 with increased acceptability during storage.

Tracking Bacillus cereus in UF-feta cheese processing line

Three processing lines for the manufacture of feta cheese from ultrafiltered (UF) milk (UF-feta) and manufacturing conditions were evaluated for product contamination, especially for the probable occurrence of Bacillus cereus. Moreover, enterotoxins from B. cereus, i.e., haemolysin and cereolysin (A and B), were analysed in isolates. Samples were collected from raw milk, after the main processing steps and the silo tanks of three UF-cheese plants. B. cereus and aerobic spores were detected at many points along the processing line. The results showed that the raw milk used to manufacture the UF-feta cheese was the main source of contamination with B. cereus. The storage tanks and UF membrane were two major factors leading to an increase in B. cereus during the process. The presence of enterotoxins in isolates also revealed that the risk of food poisoning caused by B. cereus in UF-feta cheese should not be neglected.

Development and Critical Quality Characterization of Functional UF-Feta Cheese by Incorporating Probiotic Bacteria

The addition effect of probiotic bacteria (Lactobacillus acidophilus la-5 and Bifidobacterium lactis BB-12) as single and mixed cultures on the physicochemical, proteolysis and sensory characteristics of Iranian UF-Feta cheese (IUFC) during 60 days of storage at 8C was investigated. Viability of these microorganisms was also determined. The results indicated that the probiotics population remained above 10 6 cfu/g at the storage end. The viability was not significantly affected by co-culturing. The addition of probiotic adjuncts did not exert significant effect on the proteolysis (water-soluble nitrogen and trichloroacetic acid-soluble nitrogen indices), syneresis, pH and other physicochemical properties. The presence of B. lactis BB-12 in the cheese caused a significant increase (P < 0.05) in flavor and overall acceptability. However, the cheese containing both probiotic strains were preferred over the other manufactured cheese. IUFC is a suitable carrier of L. acidophilus la-5 and B. lactis BB12 with an increased flavor and overall acceptability.

Influence of Resistant Starch and Exopolysaccharide-Producing Streptococcus thermophilus on Viability of Lactic Acid Bacteria in low fat UF Feta Cheese during Ripening

Influence of Resistant Starch and Exopolysaccharide-Producing Streptococcus thermophilus on Viability of Lactic Acid Bacteria in low fat UF Feta Cheese during Ripening

Optimization of Operational Parameters to Fortify Iranian UF-Feta Cheese with Fish Oil Using Response Surface Methodology

This study optimized the production formulation for fortifying Iranian UF-feta cheese with fish oil. The effects of the formulation parameters of cheese fat (8, 12, 16%), fish oil (0.4, 0.8, 1.2%), whey protein concentrate (0.54, 1.08, 1.62%), cumin (0, 0.25, 0.5%) and storage time (0, 30 and 60 days) on the pH, nonfat milk solids, acidity, fat, protein, texture hardness, peroxide value and sensory properties were determined using response surface methodology. The optimum conditions were determined to be 8% cheese fat, 0.4% fish oil, 0.72% whey protein concentrate, 0.5% cumin and 30 days of storage time. Practical Application Iranian UF-feta cheese made from bovine milk is manufactured in modern dairy plants from ultrafiltered and pasteurized milk with mesophilic starter cultures and commercial microbial rennet. The main characteristics of this cheese are about 35% (w/w) total solids, 6% protein content (w/w), 16% fat content and a maximum pH of 5.2. Substitution of milk fat with a combination of oleic acid and fish oil is a good nutritional strategy to reduce the intake of saturated fatty acids in favor of healthier fatty acids.

Effects of storage time on compositional, micro-structural, rheological and sensory properties of low fat Iranian UF-Feta cheese fortified with fish oil or fish oil powder.

The fish oil (FO), and fish oil powder (FOP) at 10% of recommended daily intake (RDI) were used to make two types of fortified feta cheeses. The physicochemical, rheological and sensory properties of ripened samples at 0, 30, and 60th days of cold store (5°C) showed that the FO samples had a faster pH reduction, higher MSNF (milk solid non-fat) increase (p < 0.05) and more pores formation. Storage (G') and loss (G") moduli for both samples decreased until the 30th day of cold storage and then increased until the end of the storage time but both of them were higher for FOP samples. The index of secondary lipid oxidation or thiobarbituric acid reactive substances (TBARS) of FO was lower than FOP samples. Although the polyunsaturated fatty acids of both samples were much higher than common feta cheese, their degradation in FO was less than FOP samples after storage. The sensory scores of FO were significantly higher than FOP sample (P < 0.05), and it obtained up to 70% of overall acceptability after 30 and 60days storage for its better hardness, texture and flavor.

Optimization of UF-Feta cheese preparation, enriched by peppermint extract.

Strong antioxidant activity, antimicrobial, antiviral, antitumor, and some antiallergenic potential actions have been reported in peppermint. For daily acceptance of the benefits of this plant, UF-Feta cheese, enriched by whole peppermint extract, was prepared with different levels of Peppermint Extract (PE) (220-660μg/g cheese), starter (1.3-2.7g/100Kg retentate), rennet (1.3-2.5g/100Kg retentate), and Ripening Time (RT) (10-50days). Simultaneous effects of the considered variables were also investigated on Water-soluble Phenolic Content (WSPC), Antioxidant Activity (AOA), and Sensory Score (SS) by means of Response surface methodology. The results showed that although rennet concentration had a little positive effect on WSPC, its effect on AOA was significantly negative. It was determined that PE had a crucial role in acceptance of cheese samples and showed a negative effect on SS. More maturation of produced cheese samples effectively increased AOA. It was found that for producing cheese with maximum SS and AOA, the optimum values of variables should be applied as follows: PE, 227μg/g cheese; starter, 2.7g/100Kg retentate; rennet, 1.3g/100Kg retentate; RT, 41.7days.

تاثیر کاهش درصد چربی و مقدار کلرید کلسیم بر ویژگی های حسی و بافتی پنیر فتای فراپالایش حاصل از پودر ناتراوه اولترافیلتراسیون شیر

There is overwhelming scientific evidence that saturation fat consumption increases the risk of both coronary and cancer disease. As a result, fat reduction in UF-Feta cheese (≈ 45% fat in dry matter content) is favorable but unfortunately has some negative effects on the quality of cheese. In this research, the effect of different levels of retentate fat (0, 2, 6, 10, 14 and 18%) and CaCl2 (0 and 0.02%) on sensory (texture, taste, odor, total acceptance) and mechanical texture (texture profile analysis and penetration parameters) characteristics of UF-Feta cheese made from retentate powder was studied. The completely randomized design with two factors was used for production and data analyzing. The results of sensory test showed that cheese sample containing 10% fat retentate and 0.02% CaCl2 had highest texture score with significant difference. Therefore, the panelists were preferred taste and odor of full-fat samples and the maximum total acceptance was belonged to cheese sample made from 14% fat retentate. In texture profile analysis, fat reduction was resulted in significant decrease in gumminess, chewiness, adhesiveness, springiness and compression work but cohesiveness of samples didn’t have any significant differences. In penetration test, hardness, apparent modulus of elasticity, adhesiveness force, adhesiveness and penetration force were decreased with fat reduction. As a result, addition of 0.02% CaCl2 to retentate was increased generally the texture profile analysis and penetration parameters. Keywords: CaCl2, Cheese, Fat reduction, Feta, Texture

Accelerated Ripening of UF Feta-Cheese by Using Freeze-Shocked Culture of Lactobacillus helveticus or Barley Extract

Accelerated Ripening of UF Feta-Cheese by Using Freeze-Shocked Culture of Lactobacillus helveticus or Barley Extract

Changes in the rheological properties of Iranian UF-Feta cheese during ripening

The frequency sweep test was used to evaluate storage modulus (G′), loss modulus (G′′) and loss tangent [tan ( δ)] of Iranian UF-Feta cheese during ripening period (3, 20, 40 and 60 days). With development of ripening, storage and loss moduli increased at varying rates. The rate of increase in G′ was greater than that in G′′ resulting in a reduction in tan ( δ). That is, storage modulus was dominant to loss modulus and as a result the elasticity nature was greater than the viscous nature of cheese samples. Due to the disruption of fat globules and proteolysis, protein matrix rearranged and formed a more compact texture containing aggregates of casein. Ripening did not influence the pH level and also the concentrations of dry matter, fat, salt, and total nitrogen in dry matter. However, water soluble nitrogen increased significantly ( P < 0.05).

Bovine milk procathepsin D: Presence and activity in heated milk and in extracts of rennet-free UF-Feta cheese

Abstract Milk samples were heat-treated at 72, 85 and 99°C for 15 or 60 s, and the effect on the stability of the milk acid proteinase zymogen procathepsin D was studied by combining immunoblotting using antibodies directed against bovine cathepsin D and its propeptide and by measuring residual procathepsin D-derived activity. Approximately half of the procathepsin D-derived activity detected in milk serum remained after heat treatment at 72°C/15 s or 72°C/60 s, while heat treatment at increased temperature further reduced the detectable activity. In accordance, immunoreactive procathepsin D was detected in serum from milk heated at 72°C/15 s and 72°C/60 s, while very low amounts of immunoreactivity were observed after treatment at higher temperatures. Contrary to the decrease in milk serum, the amount of procathepsin D antigen associated with casein micelles slightly increased with the temperature of the heat treatment, but still the measurable proteolytic activity derived from procathepsin D in the casein micelle samples decreased with temperature treatment. Moreover, the presence of procathepsin D and derived proteolytic activity was demonstrated in rennet free UF-Feta cheese. These results correlated with the finding of α s1 -I and para- κ -caseins in rennet free cheese. This is the first demonstration of procathepsin D in cheese, and of activity derived from indigenous procathepsin D in milk contributing to the proteolysis process in UF-products.