Proteolytic pattern and organic acid profiles of probiotic Cheddar cheese as influenced by probiotic strains of Lactobacillus acidophilus, Lb. paracasei, Lb. casei or Bifidobacterium sp

Probiotic Potential and Application of Indigenous Non-Starter Lactic Acid Bacteria in Ripened Short-Aged Cheese

There are massive sources of lactic acid bacteria (LAB) in traditional dairy products. Some of these indigenous strains could be novel probiotics with applications in human health and supply the growing needs of the probiotic industry. In this work, were analyzed the probiotic and technological properties of three Lactobacilli strains isolated from traditional Brazilian cheeses. In vitro tests showed that the three strains are safe and have probiotic features. They presented antimicrobial activity against pathogenic bacteria, auto-aggregation values around 60%, high biofilm formation properties, and a survivor of more than 65% to simulated acid conditions and more than 100% to bile salts. The three strains were used as adjunct cultures separately in a pilot-scale production of Prato cheese. After 45 days of ripening, the lactobacilli counts in the cheeses were close to 8 Log CFU/g, and was observed a reduction in the lactococci counts (around -3 Log CFU/g) in a strain-dependent manner. Cheese primary and secondary proteolysis were unaffected by the probiotic candidates during the ripening, and the strains showed no lipolytic effect, as no changes in the fatty acid profile of cheeses were observed. Thus, our findings suggest that the three strains evaluated have probiotic properties and have potential as adjunct non-starter lactic acid bacteria (NSLAB) to improve the quality and functionality of short-aged cheeses.

Evaluation of Pediococcus acidilacticiAS185 as an adjunct culture in probiotic cheddar cheese manufacture

A novel probiotic Pediococcus acidilactici AS185, isolated from traditional Chinese fermented foods, was used as an adjunct culture for probiotic cheddar cheese production. The physicochemical composition, textural, free amino acids (FAAs), short-chain fatty acids (SCFAs) profiles, sensory properties, and microbial survival, was evaluated during the 90-day ripening period. The addition of P. acidilactici AS185 did not influence the physicochemical composition of cheddar cheese but significantly decreased the hardness without affecting its textural profile. During ripening, P. acidilactici AS185 was able to grow and promote the generation of FAAs and SCFAs, but did not alter the overall sensory properties; it rather improved the flavor and taste of cheese. In addition, the cheese matrix protected strain P. acidilactici AS185 during transit throughout the simulated gastrointestinal system. These results demonstrated that P. acidilactici AS185 adjunct cultures might be useful for producing high-quality probiotic cheddar cheese.

Protease produced by Lactobacillus brevis enhanced nutritional values of African yam beans and demonstrated improvement in the growth and blood indices of albino rats

This study evaluates the nutritional values of African yam bean hydrolyzed with protease from Lactobacillus brevis and afterward assess its effect on the growth and blood parameters of albino rats. The nutritional compositions of AYB hydrolyzed with partially purified protease from L. brevis were determined by standard chemical methods. The protease-hydrolyzed AYB was thereafter formulated into feeds with different inclusion levels (20, 40 and 60%), which was used to feed albino rats for 27 days. After the feeding trial, the blood of anesthetized albino rats was collected using the cardiac puncture method, and the hematological parameters were determined by standard biochemical methods. The AYB hydrolyzed with partially purified protease had the highest percentage crude protein with a value of 31.2% when compared with boiled, soaked and boiled, and raw sample with the values of 20.9, 20.9 and 19.9%, respectively. The treatment of AYB with purified protease also resulted in an increase of vitamins and some essential amino acids when compared with unhydrolyzed AYB. The group of rats fed with 60% hydrolyzed AYB had the highest percentage average weight gain of approximately 144%, while the values recorded for the groups fed with commercial feed and unhydrolyzed AYB were approximately 86 and 101%, respectively. The hematological analysis revealed that the hemoglobin (Hb) and packed cell volume (PCV) of the group fed with 40% hydrolyzed AYB of 14 g/L and 38% respectively, were significantly higher than the rats fed with commercial feed with values of 10 g/L and 32%, respectively. Thus, enzyme-hydrolyzed AYB might be a suitable alternative to animal protein with good functional properties.

Descriptive Sensory Analysis of Pizza Cheese Made from Mozzarella and Semi-Ripened Cheddar Cheese Under Microwave and Conventional Cooking

The present study used descriptive sensory analysis (DSA) to compare Pizza cheeses prepared from various combinations of fresh Mozzarella and semi-ripened Cheddar cheeses and cooked under conventional and microwave cooking methods. A cheese sensory lexicon was developed, and descriptive sensory profiles of the Pizza cheeses were evaluated using a panel of semi-trained judges (n = 12). The following characteristics, flavor (cheddar, acidic, rancid, bitter, salty, creamy, and moldy), texture (stringiness, stretchability, firmness, and tooth pull), and appearance (meltability, oiliness, edge browning, and surface rupture) of Pizza cheeses were analyzed and compared with control samples. The sensory analysis of Pizza cheeses showed more preference toward a higher level of ripened Cheddar cheese (4 months), which was cooked using the microwave. However, the scores for texture properties were decreased with the addition of the semi-ripened cheese. The scores for stretchability and tooth pull were high in the microwave cooked samples compared with the conventionally cooked samples. The appearance attributes (meltability, oiliness, and edge browning) scores were increased with the increasing of ripened Cheddar cheese content while surface rupture was decreased. Microwave cooked Pizza cheese showed better meltability and oiliness but lower edge browning scores. The results showed that amalgamations of fresh Mozzarella and semi-ripened Cheddar cheese had a significant (p < 0.05) and positive effects on the sensory qualities of Pizza cheeses.

Cheese as a Potential Food Carrier to Deliver Probiotic Microorganisms into the Human Gut: A Review

:

This review presents the industrial manufacture and applications of cheese for the delivery of probiotic microorganisms into the human gut. Initially, important benefits of probiotics and advantageous characteristics of cheese for the delivery of probiotic microorganisms into the human gut in comparison with the other fermented milk products are discussed. Fresh and ripened cheeses are also separately argued followed by discussing queries respecting the viability of probiotic bacteria into these cheeses. Since fresh cheese has been demonstrated as more suitable carriers for probiotic microorganisms, factories are recommended producing it in large quantities.

Bioprospecting for Bioactive Peptide Production by Lactic Acid Bacteria Isolated from Fermented Dairy Food

With rapidly ageing populations, the world is experiencing unsustainable healthcare from chronic diseases such as metabolic, cardiovascular, neurodegenerative, and cancer disorders. Healthy diet and lifestyle might contribute to prevent these diseases and potentially enhance health outcomes in patients during and after therapy. Fermented dairy foods (FDFs) found their origin concurrently with human civilization for increasing milk shelf-life and enhancing sensorial attributes. Although the probiotic concept has been developed more recently, FDFs, such as milks and yoghurt, have been unconsciously associated with health-promoting effects since ancient times. These health benefits rely not only on the occurrence of fermentation-associated live microbes (mainly lactic acid bacteria; LAB), but also on the pro-health molecules (PHMs) mostly derived from microbial conversion of food compounds. Therefore, there is a renaissance of interest toward traditional fermented food as a reservoir of novel microbes producing PHMs, and “hyperfoods” can be tailored to deliver these healthy molecules to humans. In FDFs, the main PHMs are bioactive peptides (BPs) released from milk proteins by microbial proteolysis. BPs display a pattern of biofunctions such as anti-hypertensive, antioxidant, immuno-modulatory, and anti-microbial activities. Here, we summarized the BPs most frequently encountered in dairy food and their biological activities; we reviewed the main studies exploring the potential of dairy microbiota to release BPs; and delineated the main effectors of the proteolytic LAB systems responsible for BPs release.

Extracellular Proteolytic Activity and Amino Acid Production by Lactic Acid Bacteria Isolated from Malaysian Foods

Amino acids (AAs) are vital elements for growth, reproduction, and maintenance of organisms. Current technology uses genetically engineered microorganisms for AAs production, which has urged the search for a safer food-grade AA producer strain. The extracellular proteolytic activities of lactic acid bacteria (LAB) can be a vital tool to hydrolyze extracellular protein molecules into free AAs, thereby exhibiting great potential for functional AA production. In this study, eight LAB isolated from Malaysian foods were determined for their extracellular proteolytic activities and their capability of producing AAs. All studied LAB exhibited versatile extracellular proteolytic activities from acidic to alkaline pH conditions. In comparison, Pediococcus pentosaceus UP-2 exhibited the highest ability to produce 15 AAs extracellularly, including aspartate, lysine, methionine, threonine, isoleucine, glutamate, proline, alanine, valine, leucine, tryptophan, tyrosine, serine, glycine, and cystine, followed by Pediococcus pentosaceus UL-2, Pediococcus acidilactici UB-6, and Pediococcus acidilactici UP-1 with 11 to 12 different AAs production detected extracellularly. Pediococcus pentosaceus UL-6 demonstrated the highest increment of proline production at 24 h of incubation. However, Pediococcus acidilactici UL-3 and Lactobacillus plantarum I-UL4 exhibited the greatest requirement for AA. The results of this study showed that different LAB possess different extracellular proteolytic activities and potentials as extracellular AA producers.

Influence of milling pH and storage on quality characteristics, mineral and fatty acid profile of buffalo Mozzarella cheese

BACKGROUND

Currently, cheese fat is a major component of human diet due to change in eating habits. It contains a number of health destroying as well as health promoting fatty acids. Bovine milk cheese fatty acid composition is regulating by many factors. These may be breed of animal, animal health condition like mastitis and stage of lactation. It also differs with feed and dietary fat intake and seasons. Many studies demonstrated physicochemical, textural and sensory characteristics of Mozzarella cheese with variation in technological process but no literature found about the fatty acid profile and potential influence of milling pH on the fatty acid composition of buffalo Mozzarella cheese.

METHODS

Buffalo Mozzarella cheeses were manufactured at 5.2, 5.1, 5.0, 4.9 and 4.8 milling pH, vacuum packaged and stored at 4 °C and analyzed for quality characteristics, mineral composition and fatty acid profile on days 1, 45, and 90. Results were analyzed by ANOVA according to complete randomized design.

RESULTS

This study evaluated the effect of milling pH on chemical composition, mineral and fatty acid profile of buffalo Mozzarella cheese. Experimentally induced milling pH differences persisted and significantly affected chemical composition during first day of manufacturing but have no effect on fatty acid profile of cheese. However, storage effects significantly on chemical composition and fatty acid profile of cheese. Decreasing milling pH from 5.2-4.9 resulted in decrease in moisture content of cheese. As a result of changes in milling pH, all the cheeses experienced a significant loss in protein content. In contrast to protein content, fat content of cheese increases with decreasing milling pH. Ash contents of cheese decreased with decreasing milling pH. The level of calcium decreases from 77.82 mg/g to 69.1 mg/g with decreasing milling pH while there is no clear trend observed for potassium and sodium during change in milling pH. Saturated fatty acids presented higher concentrations reaching values of about 71.38 g/100 g throughout storage while monounsaturated fatty acids decreases with storage from 26.72 to 22.06 g/100 g. On the other hand, total polyunsaturated fatty acids exhibited lower concentrations than total monounsaturated fatty acids reaching values of 3.2 g/100 g and its value also decreased with ripening and reached to 1.6 g/100 g. Concentration of C18:1 t10-11 was observed 1.89% in freshly prepared cheese. Milling pH did not influence C18:1 t10-11 concentration but storage days significantly (p < 0.05) decreased its concentration.

CONCLUSION

In modern era, Mozzarella cheese is major source of dietary fatty acids. The study demonstrated that Mozzarella cheese is a rich source of saturated fatty acids that has detrimental effect on health but it is also observed that it is also a major source of essential fatty acids that has beneficial impact on health. It is concluded that technological conditions like milling pH minimally influence cheese fatty acid profile but after manufacturing treatments and conditions like packaging and storage greatly influence fatty acid profile of cheese. It was concluded that cheese may get oxidized if it is packed in inappropriate packaging material that have reduced air barrier resistance. Moreover, cheese storage under light may also become oxidized which is also harmful for health.

Effects of Apricot Fibre on the Physicochemical Characteristics, the Sensory Properties and Bacterial Viability of Nonfat Probiotic Yoghurts

In this study, the physical, chemical, rheological, and microbiological characteristics and the sensory properties of nonfat probiotic yoghurt produced at two different concentrations of apricot fibre (1% and 2%, w/v) and three different types of probiotic culture (Lactobacillus (L.) acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12), and their mixtures) were investigated. As the fibre content increased, the rheological, structural, and sensory properties of probiotic yoghurt were negatively affected, while counts of L. delbrueckii subsp. bulgaricus, L. acidophilus LA-5, and Bifidobacterium BB-12 increased. When all the results were evaluated, the best results were obtained by using L. acidophilus LA-5 as probiotic culture and adding 1% (w/v) apricot fibre.

Compositional and textural properties of goat’s milk cheese prepared using dahi (yogurt) as the starter culture

Abstract This study aimed to develop goat’s milk cheese to conserve the major milk constituents. Household dahi (yoghurt) is an inexpensive source of starter cultures that contains several types of microorganism of which most are thermophilic in nature and can be used in the production of goat’s milk cheese. Different concentrations of dahi (0.5%, 1.0%, 1.5%, 2.0% and 2.5%) were used to prepare the cheeses following the standard procedure for cheese manufacturing. The cheeses were analysed for their physicochemical, textural and organoleptic parameters. The highest yield was recorded for T1.0% (17.33%) and the lowest for T2.5% (15.58%). Significant (p < 0.05) differences were found for the pH, acidity and moisture content of the different goat’s milk cheese samples. The moisture content was highest in T0.5% (59.30) and lowest in T2.5% (52.20). The texture profile was significant (p < 0.05) for firmness, adhesiveness, gumminess and chewiness between the treatments. The sensory scores indicated that T1.0% was preferred by the panellists, followed by T1.5% and then the other treatments. It was concluded that goat’s milk cheese could be prepared with good quality characteristics using 1% dahi as the starter culture.

Evaluation of the Potential of Lactobacillus paracasei Adjuncts for Flavor Compounds Development and Diversification in Short-Aged Cheddar Cheese

The non-starter microbiota of Cheddar cheese mostly comprises mesophilic lactobacilli, such as Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Lactobacillus plantarum. These bacteria are recognized for their potential to improve Cheddar cheese flavor when used as adjunct cultures. In this study, three strains of L. paracasei (DPC2071, DPC4206, and DPC4536) were evaluated for their contribution to the enhancement and diversification of flavor in short-aged Cheddar cheese. The strains were selected based on their previously determined genomic diversity, variability in proteolytic enzyme activities and metabolic capability in cheese model systems. The addition of adjunct cultures did not affect the gross composition or levels of lipolysis of the cheeses. The levels of free amino acids (FAA) in cheeses showed a significant increase after 28 days of ripening. However, the concentrations of individual amino acids in the cheeses did not significantly differ except for some amino acids (aspartic acid, threonine, serine, and tryptophan) at Day 14. Volatile profile analysis revealed that the main compounds that differentiated the cheeses were of lipid origin, such as long chain aldehydes, acids, ketones, and lactones. This study demonstrated that the adjunct L. paracasei strains contributed to the development and diversification of compounds related to flavor in short-aged Cheddar cheeses.

Quality improvement of spreadable processed cheese made from ultrafiltered milk retentates using commercial starter cultures

This study was undertaken to evaluate the feasibility of using commercial starter cultures for quality improvement of spreadable processed cheese manufactured from ultrafiltered milk retentates. Compared to control, six samples of ultrafiltered milk retentate were incubated at 25 ℃ with starter cultures CHN-22, FRC-60, and ABT-8. Three samples were incubated for 24 h and the others were incubated for 72 h. Physicochemical, microbiological, and organoleptic characteristics in all treatments during the 90-day cold storage (6 ± 2 ℃) period were determined. The results showed that protein content of all treatments was significantly lower than the control. Utilization of starter cultures in ultrafiltered processed cheese production increased titratable acidity, where titratable acidity of the treatments (PC_22-3, PC_60-3, and PC_8-3) was significantly higher than the other treatments and the control. PC_8-1, PC_60-1, and PC_22-1 treatments were the highest penetrometer readings and with low firmness. All treatments had higher water soluble nitrogen/total nitrogen%, total bacterial viable and lactic acid bacterial counts especially PC_22-3, PC_60-3, and PC_8-3 compared to the control. The results revealed that PC_60-1 and PC_22-3 treatments gained the highest acceptability scores than PC_60-3, PC_22-1, and the control.

Dietary Fibers and Protective Lactobacilli Drive Burrata Cheese Microbiome

This study was aimed at improving the functional attributes and shelf life of burrata cheese by using protective lactobacilli (Lactobacillus plantarum LPAL and Lactobacillus rhamnosus LRB), fructooligosaccharides, and inulin. Six burrata cheeses were made using (i) the traditional protocol (control), (ii) the addition of 0.5% fructooligosaccharides and inulin (DF cheese), (iii) protective lactobacilli in milk alone (PL cheese), (iv) protective lactobacilli in milk and governing liquid (2PL cheese), (v) protective lactobacilli in milk and dietary fibers (DF_PL cheese), and (vi) protective lactobacilli in milk and governing liquid and dietary fibers (DF_2PL cheese). As expected, DF, DF_PL, and DF_2PL cheeses showed 1.5% of total fibers. Burrata cheeses produced by adding protective lactobacilli only in milk (PL and DF_PL cheeses) showed the lowest acidification during cheese making and storage. Lactic and acetic acids and ethanol were found at the lowest concentrations in these samples. Analyses of cultivable microbiota and the microbiome showed that protective lactobacilli reduced the house microbiota components (e.g., Streptococcus thermophilus, Lactococcus lactis, and Leuconostoc lactis) during cheese making and storage. Protective lactobacilli slowed the growth of staphylococci, coliforms, and Pseudomonas spp., especially in early storage. According to the different microbiome assemblies, burrata samples differed in peptide profiles and the levels of free amino acids. As shown by a sensory analysis, the addition of protective lactobacilli in milk improved the flavor and increased the shelf life of burrata cheese. In comparison to cheeses made using protective cultures only in milk, the shelf lives of those containing cultures also in the governing liquid were not further prolonged and they received lower acceptability scores by the panelists.IMPORTANCE This study provides more in-depth knowledge of the microbiome of burrata cheese and the set-up for a novel biotechnology using prebiotic dietary fibers and protective probiotic Lactobacillus plantarum LPAL and Lactobacillus rhamnosus LRB in milk. The biotechnology proposed in this study should be considered a useful tool to improve the functional value of burrata cheese. The use of protective lactobacilli in milk enhanced the flavor formation and shelf life of burrata cheese.

Antioxidant potential of buffalo and cow milk Cheddar cheeses to tackle human colon adenocarcinoma (Caco-2) cells

Objective

The aim of present study was to assess the anti-oxidant potential of water-soluble peptides (WSPs) extract derived from buffalo and cow milk Cheddar cheeses at different stages of ripening.

Methods

The antioxidant potential of WSPs extract was assessed through 2,2’-azinobis-3-ethylbenzothiazoline-6sulfonic acid (ABTS)-radical scavenging activity. In addition, impact of WSPs extract on cell viability and production of reactive oxygen species (ROS) in human colon adenocarcinoma Caco-2 (tert-butylhydroperoxide-induced) cell lines was also evaluated.

Results

The ABTS-radical scavenging activity increased progressively with ripening period and dose-dependently in both cheeses. However, peptide extract from buffalo milk Cheddar cheese demonstrated relatively higher activity due to higher contents of water-soluble nitrogen. Intracellular ROS production in Caco-2 cells decreased significantly (p<0.05) till 150th day of cheese ripening and remained constant thereafter. Additionally, dose-dependent response of WSPs extract on antioxidant activity was noticed in the Caco-2 cell line.

Conclusion

On the basis of current in vitro study, the Cheddar cheese WSPs extract can protect intestinal epithelium against oxidative stress due to their antioxidant activity.

Effect of Monascus sp. as an adjunct starter on physicochemical properties and proteolysis in semi-hard cheeses during ripening

Two kinds of semi-hard cheeses, with Monascus purpureus and without M. purpureus, were manufactured, and effects of M. purpureus on physicochemical properties and proteolysis were evaluated during 36 days of ripening. Addition of M. purpureus changed the microbial survival and showed no significant effect on physicochemical properties of the cheeses, including dry matter and pH. Regardless on the rind or in the core, the indices of proteolysis had no significant difference (p>0.05), whereas there were significant differences of total free amino acid (FAA) and individual FAA between cheeses; this indicated that M. purpureus had no significant effect on the primary proteolysis, but affected the content and ratio of individual FAAs during maturation. Electrophoretic analysis showed strong degradation of αs1-casein in the core and on the rind of cheeses, while β-casein was highly degraded on the rind but less in the core. Thus, Monascus spp. might have a potential application in the manufacture of cheeses.

Physicochemical, microbiological and spoilage analysis of probiotic processed cheese analogues with reduced emulsifying salts during refrigerated storage

Microbial quality of low-salt processed cheeses supplemented with Bacillus coagulans spores (10(7)-10(8) CFU/g) relying on their physicochemical characteristics during 60 day-cold storage was evaluated. A reduction in moisture content, water activity and pH value and a significant enhancement in proteolytic index of control and probiotic samples were obtained by prolonging storage time. Survival rate of the probiotic cells significantly decreased up to day 30, while total count of the viable cells increased by increasing storage time. A 20 and 67 % increase in total counts of coliforms and mold-yeast of the control sample were respectively observed after 60 days of cold storage. A considerable decrease in the total counts of coliforms and mold-yeast was also found in the processed cheeses containing probiotic supplement. According to the macroscopic and sensory assessment, off-odors and off-flavors in the control sample were diagnosed after day 1 of cold-storage. Noticeably, the resistance to spoilage was more prominent in samples containing the probiotic cells.

Stress responses in probiotic Lactobacillus casei

Survival in harsh environments is critical to both the industrial performance of lactic acid bacteria (LAB) and their competitiveness in complex microbial ecologies. Among the LAB, members of the Lactobacillus casei group have industrial applications as acid-producing starter cultures for milk fermentations and as specialty cultures for the intensification and acceleration of flavor development in certain bacterial-ripened cheese varieties. They are amongst the most common organisms in the gastrointestinal (GI) tract of humans and other animals, and have the potential to function as probiotics. Whether used in industrial or probiotic applications, environmental stresses will affect the physiological status and properties of cells, including altering their functionality and biochemistry. Understanding the mechanisms of how LAB cope with different environments is of great biotechnological importance, from both a fundamental and applied perspective: hence, interaction between these strains and their environment has gained increased interest in recent years. This paper presents an overview of the important features of stress responses in Lb. casei, and related proteomic or gene expression patterns that may improve their use as starter cultures and probiotics.

High resolution melting analysis (HRM) as a new tool for the identification of species belonging to the Lactobacillus casei group and comparison with species-specific PCRs and multiplex PCR

The correct identification and characterisation of bacteria is essential for several reasons: the classification of lactic acid bacteria (LAB) has changed significantly over the years, and it is important to distinguish and define them correctly, according to the current nomenclature, avoiding problems in the interpretation of literature, as well as mislabelling when probiotic are used in food products. In this study, species-specific PCR and HRM (high-resolution melting) analysis were developed to identify strains belonging to the Lactobacillus casei group and to classify them into L. casei, Lactobacillus paracasei and Lactobacillus rhamnosus. HRM analysis confirmed to be a potent, simple, fast and economic tool for microbial identification. In particular, 201 strains, collected from International collections and attributed to the L. casei group, were examined using these techniques and the results were compared with consolidated molecular methods, already published. Seven of the tested strains don't belong to the L. casei group. Among the remaining 194 strains, 6 showed inconsistent results, leaving identification undetermined. All the applied techniques were congruent for the identification of the vast majority of the tested strains (188). Notably, for 46 of the strains, the identification differed from the previous attribution.

Development of a potential probiotic fresh cheese using two Lactobacillus salivarius strains isolated from human milk

Cheeses have been proposed as a good alternative to other fermented milk products for the delivery of probiotic bacteria to the consumer. The objective of this study was to assess the survival of two Lactobacillus salivarius strains (CECT5713 and PS2) isolated from human milk during production and storage of fresh cheese for 28 days at 4°C. The effect of such strains on the volatile compounds profile, texture, and other sensorial properties, including an overall consumer acceptance, was also investigated. Both L. salivarius strains remained viable in the cheeses throughout the storage period and a significant reduction in their viable counts was only observed after 21 days. Globally, the addition of the L. salivarius strains did not change significantly neither the chemical composition of the cheese nor texture parameters after the storage period, although cheeses manufactured with L. salivarius CECT5713 presented significantly higher values of hardness. A total of 59 volatile compounds were identified in the headspace of experimental cheeses, and some L. salivarius-associated differences could be identified. All cheeses presented good results of acceptance after the sensory evaluation. Consequently, our results indicated that fresh cheese can be a good vehicle for the two L. salivarius strains analyzed in this study.

Bioactivity of probiotic whey cheese: characterization of the content of peptides and organic acids

BACKGROUND

Probiotic whey cheeses have been produced for several years. It is recognized that several bacterium-mediated metabolic activities contribute differently to the final sensory and nutritional profiles of dairy products. Hence the metabolic activity of probiotic strains in a whey cheese and their contribution to the bioactivity of such matrices were investigated here, including in particular Bifidobacterium animalis, Lactobacillus acidophilus and Lactobacillus casei.

RESULTS

Both L. casei and B. animalis produce lactic and acetic acids, whereas L. acidophilus produce mainly lactic acid; these metabolites may be considered bioprotection factors. Water-soluble extracts (WSE) obtained from these cheese matrices were subjected to ultrafiltration through a 3 kDa cut-off membrane, and the eluted peptides were resolved by high-performance liquid chromatography. Different qualitative and quantitative profiles were obtained, depending on the strain. WSE were further assayed for their ability to inhibit angiotensin-converting enzyme; the <3 kDa fraction exhibited higher activities in the case of L. casei and B. animalis than the control and L. acidophilus.

CONCLUSION

Whey cheeses with higher nutritional value were those inoculated with L. casei.