Resistance of Microencapsulated <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> LA1 to Processing Treatments and Simulated Gut Conditions

This investigation reports the effect of microencapsulation using sodium alginate and starch on the tolerance of probiotic Lactobacillus acidophilus LA1 to selected processing conditions and simulated gastrointestinal environments. The organism survived better in the protected form at high temperatures (72, 85, and 90 °C) and at high salt concentrations (1%, 1.5%, and 2%). The free cells were completely destroyed at 90 °C whereas the microencapsulated cells reduced by 4.14 log cycles. The log cycle reduction was 5.67 and 2.30, respectively, in free and protected cells when incubated for 3 h with 2% (w/v) NaCl. Homogenization did not affect the viability of the cells but led to the disruption of the protective encapsulating material around the cells. Microencapsulation provided better protection at simulated conditions of gastric pH (1.0, 1.5, and 2.0) and at high bile salt concentrations (1.0%, 1.5%, and 2.0%). The free and protected cells registered 5.47 and 2.16 log cycle reduction, respectively, after 3-h incubation at 2% bile salt (w/v). The release of the microencapsulated organisms in simulated colonic pH required 2.5 h. These studies demonstrated that microencapsulation of probiotic L. acidophilus LA1 in sodium alginate is an effective technique of protection against extreme processing conditions and under simulated gastrointestinal environment.     

Effects of encapsulation on the viability of probiotic strains exposed to lethal conditions

The effect of microencapsulation on the viability of Lactobacillus casei, L. paracasei, L. acidophilus Ki and Bifidobacterium animalis BB‐12 during exposure to lethal conditions (25% NaCl, pH 3.0 and 55–60 °C) was evaluated. Results demonstrated that survival of probiotic strains to the imposed lethal stress conditions was strain dependent. With the exception of exposure to 25% (w/v) NaCl, L. acidophilus Ki (free and encapsulated cells) demonstrated the highest survival rates through exposure to lethal conditions of temperature and pH. For this probiotic strain exposed to heat, microencapsulated cells expressed a higher heat tolerance at 55 °C than free cells. For the other tested bacteria, in general, encapsulation had no positive effect on survival through the tested lethal conditions.     

Storage Stability of Lactobacillus paracasei as Free Cells or Encapsulated in Alginate-Based Microcapsules in Low pH Fruit Juices

The main objective of this research effort was to study whether microencapsulation could be a viable alternative to obtain probiotic orange or peach juices. In order to be considered probiotic food, probiotic bacteria must be present in sufficient viable numbers to promote a benefit to the host. The survival and viability of Lactobacillus paracasei L26 in juices over 50?days of storage at 5°C was assessed, evaluating the potential use of encapsulated cells in alginate microcapsules. L. paracasei L26 demonstrated good viability in both orange and peach juices despite the low pH values of both juices. Microencapsulation in alginate, with or without double coating, revealed to be suitable to protect L. paracasei L26 since viable cells were approximately 9 log cfu/g after 50?days of storage at 5°C. In general, the probiotic fruit juices showed a decrease in pH during storage. Glucose and fructose contents as well as citric acid contents decreased during storage, whereas an increase in formic acid was observed. The outcome of this study points to L. paracasei L26 as having promising potential, especially in an encapsulated form, as functional supplements in fruit juices without dairy ingredients due to their tolerance in an acidic environment over 50?days of storage at 5°C. Further studies are warranted to prove the functionality of juices with encapsulated probiotic strains.     

Spray-Drying of Probiotic Cashew Apple Juice

Data on spray-drying of fruit juices containing probiotic bacteria are scarce. The main challenge is to avoid the viability losses of the microorganism during drying and storage. In the presented study, the dehydration by spray-drying of cashew apple juice containing Lactobacillus casei NRRL B-442, and the influence of the storage temperature (25 and 4 °C) on the viability of L. casei NRRL B-442 and on the physical properties of the powder during 35 days of storage were evaluated. Probiotic cashew apple juice was dehydrated according to the following conditions: inlet temperature of the drying air (120 °C), feed flow rate of juice (0.3 L/h), hot air flow (3.0 m³/min), and pressurized air flow (30 L/min). The outlet temperature was 75 °C. The carriers used were 20 % (w/v) maltodextrin or 10 % (w/v) maltodextrin + 10 % (w/v) gum arabic. Microbial survival rates higher than 90 % were obtained for the powder stored at 4 °C for 35 days (both carriers) and higher than 70 % up to 21 days for the powder obtained using only maltodextrin at 25 °C. Higher yields were obtained only by maltodextrin which was used as carrier (72 %) compared to the yield obtained when the mixture of maltodextrin and gum arabic was applied (60 %). The water activity was kept low (Aw?<?0.30) during the storage, and the characteristic color of the product was maintained.     

Characterisation,storage viabilit,and application of microspheres with Lactobacillus paracasei obtained by the extrusion technique

The objective of this study was to evaluate the influence of pH, bile salts and different storage conditions at two different temperatures (30 and 4 °C) on the viability of free and microencapsulated Lactobacillus paracasei. Microspheres encapsulating L. paracasei were obtained using an extrusion method. The efficiency was 87.6%, the diameter 70 µm and the zeta potential 7.22 ± 0.05 mV. Encapsulated L. paracasei showed higher resistance to stomach pH and bile salts compared to free cells. Microspheres were evaluated under four different storage conditions: fresh, suspended in a solution with a pH of 4, suspended in saline solution and lyophilised. The lyophilised microspheres presented the highest stability with 89.2% survival rate after six weeks of storage; however, free bacteria in saline solution (0.145 N) presented a 65.3% survival rate. Finally, a new product (a strawberry ice popsicle) with possible functional characteristics was obtained using microencapsulated L. paracasei.     

Probiotic bacteria as adjunct starters: influence of the addition methodology on their survival in a semi-hard Argentinean cheese

Two strains of probiotic bacteria, one of Lactobacillus acidophilus and the other of Lactobacillus paracasei subsp. paracasei, were tested as adjunct cultures in cheese-making experiments, in order to assess their viability during cheese-making and ripening. The adjunct culture was added to cheese-making milk following two different methodologies: as a lyophilized powder dispersed in milk, or within a substrate composed of milk and milk fat. In all cheeses, probiotic bacteria increased a log cycle during cheese-making, and remained almost constant during ripening (60 days), always in higher number than required to meet probiotic standards. Gross composition of the cheeses was not affected by the addition of probiotic bacteria, except for pH value: cheeses with L. acidophilus added within the pre-incubated substrate, had lower pH values and were over acidified and crumbly. Direct addition of the probiotic culture was the methodology with the best performance; however the pre-incubation presented some advantages such as an increased population of lactobacilli in the initial inoculum.     

Storage Stability and Acceptance of Probiotic Beverage from Cashew Apple Juice

The stability of nonfermented cashew apple juice (control) and the fermented juice with Lactobacillus casei NRRL B-442 (sweetened and nonsweetened samples) was investigated along the storage at 4 °C for 42 days. The viability of the probiotic bacteria, sugars, lactic acid, and vitamin C content besides color, antioxidant activity, enzyme activity, and sensory characteristics of probiotic cashew apple juice was evaluated. It was observed that viable cell counts increased in the probiotic cashew apple containing sucrose (8 % w/v) along the storage period. Viable cell counts were always higher than 8.00 Log CFU/ml throughout the storage period. Ascorbic acid loss was higher in the nonfermented juice (40 %) compared to the fermented juice (23 %). The same behavior was observed for antioxidant activity and total polyphenolic compounds content, conferring nutritional benefits to this functional food. Browning reactions and nutritional breakdown caused by enzymes were minimized in the fermented samples during storage. In the fermented sample, higher reduction (>70 %) in the polyphenol oxidase enzyme activity was observed. During storage, the increase in the chroma values from 3.2 to 5.0 indicated that the yellow color became more vivid. Sensory analysis of the fermented cashew apple juice revealed that the product was well-accepted, with acceptance percentages above 80 % for the sweetened juice at the end of the storage period.     

Spray-drying microencapsulation using whey protein isolate and nano-crystalline starch for enhancing the survivability and stability of Lactobacillus reuteri TF-7

Decrease of survivability and stability is a major problem affecting probiotic functional food. Thus, in this study, Lactobacillus reuteri TF-7 producing bile salt hydrolase was microencapsulated in whey protein isolate (WPI) or whey protein isolate combined with nano-crystalline starch (WPI-NCS) using the spray-drying technique to enhance the survivability and stability of probiotics under various adverse conditions. Spherical microcapsules were generated with this microencapsulation technique. In addition, the survival of L. reuteri TF-7 loaded in WPI-NCS microcapsules was significantly higher than WPI microcapsules and free cells after exposure to heat, pH, and simulated gastrointestinal conditions. During long-term storage at 4, 25, and 35 °C, WPI-NCS microcapsules could retain both survival and biological activity. These findings suggest that microcapsules fabricated from WPI-NCS provide the most robust efficiency for enhancing the survivability and stability of probiotics, in which their great potentials appropriate to develop as the cholesterol-lowering probiotic supplements.     

Potentially probiotic and synbiotic chocolate mousse

Several studies in recent years have shown the benefits deriving from the ingestion of probiotics, and a large number of products containing lactobacilli and bifidobacteria have been formulated. The purpose of this study was to develop a chocolate mousse to which probiotic and prebiotic ingredients were added, and verify the perspectives of the product with regard to potential for consumer health benefits and sensorial acceptance. Probiotic and synbiotic chocolate mousse supplemented with Lactobacillus paracasei subsp. paracasei LBC 82, solely (P) or together with the prebiotic ingredient inulin (S), were prepared, as well as a control mousse (C). The products were monitored for the population of L. paracasei and contaminants, during storage at 5 °C for up to 28 days, and sensory preference was also tested. Storage trials showed that the viability of the probiotic was retained over 28 days, but the growth of yeasts and moulds might limit the shelf-life of the product. Chocolate mousse was shown to be an excellent vehicle for the delivery of L. paracasei, and the prebiotic ingredient inulin did not interfere in its viability. Moreover, the addition of the probiotic microorganism and of the prebiotic ingredient did not interfere in the sensorial preference of the product.     

Lactic acid bacteria with cholesterol-lowering properties for dairy applications: In vitro and in situ activity

Cholesterol-lowering activity is one of the most promising properties of lactic acid bacteria with probiotic characteristics. In the present study, 58 potentially probiotic lactic acid bacteria were tested for their ability to survive in vitro digestion and reduce cholesterol in a medium containing cholesterol and bile acids. The best-performing strains (Lactobacillus casei VC199, Lactobacillus paracasei ssp. paracasei SE160 and VC213, Lactobacillus plantarum VS166 and VS513, Enterococcus faecium VC223, and Enterococcus lactis BT161) resulted in a 42 to 55% reduction of the cholesterol level in broth and were further tested in cheese manufacture. The cholesterol content in all the cheeses decreased with ripening. All the strains were present in the cheese at levels higher than 10⁷ cfu/g until 60 d of ripening, the highest reductions (up to 23%) being obtained when Lb. paracasei ssp. paracasei VC213 and E. lactis BT161 were added during the cheese-making. The adjunct cultures had no negative effect on the sensory characteristics of the cheese. Thus, these strains with proven in vitro properties are good candidates for novel probiotic-containing formulations and could be used to functionalize foods such as dairy fermented products.     

Survival and activity of 5 probiotic lactobacilli strains in 2 types of flavored fermented milk

The viability of 5 probiotic lactobacilli strains (Lactobacillus acidophilus LA-5, Lactobacillus casei L01, Lactobacillus casei LAFTI L26, Lactobacillus paracasei Lcp37, and Lactobacillus rhamnosus HN001) was assessed in 2 types of probiotic flavored drink based on fermented milk during 21 days of refrigerated storage (5°C). Also, changes in biochemical parameters (pH, titrable acidity, and redox potential) during fermentation as well as the sensory attributes of final product were determined. Among the probiotic strains, L. casei LAFTI L26 exhibited the highest retention of viability during refrigerated storage period, while L. acidophilus LA-5 showed the highest loss of viability during this period. The decline in cell count of probiotic bacteria in strawberry fermented milk was significantly greater compared to peach fermented milk. In an overall approach, peach fermented milk containing L. casei LAFTI L26 was selected as the optimal treatment in this study in both aspects of viability and sensory accpeptibility.     

Kefir yeasts enhance probiotic potentials of Lactobacillus paracasei H9: The positive effects of coaggregation between the two strains

This study investigated pure Lactobacillus paracasei H9 tolerance to simulated gastrointestinal juices and adhesion to intestinal mucosa cells without yeasts, with viable yeasts (VY) and with different pretreated yeasts. Three models including gastric secretion tolerance (GST), intestinal juice tolerance (IJT) and sequential gastrointestinal tolerance (SGT) were respectively employed to assay the tolerance of L. paracasei H9, whilst Caco-2 cell line was used to investigate the bacterial adhesion. Particularly, the co-aggregation ability of the two strains at pH values of 2.0, 8.0 and 7.2 was originally carried out to study relations to the bacterial probiotic potentials. Results showed that yeast counts in the range from 3.0 to 5.0 log CFU mL^? 1 could gradually increase the viability of L. paracasei H9 in SGT. The bacterial viability in the three tolerance models and the adherent number to Caco-2 cells were significantly improved with addition of VY (P < 0.05). The L. paracasei H9 with VY in gastric juice at pH 2.0 and intestinal juice at pH 8.0, respectively, exhibited higher aggregation percentage compared with that of single L. paracasei H9 at 37 °C (P < 0.05). The aggregation ability of L. paracasei H9 with VY at pH 7.2, which might contribute to increase the adhesion of the bacteria, also excelled that of L. paracasei H9 (P < 0.05). It is deduced that proteins of the bacterial cell surface and polysaccharides in yeast cell walls play important roles in co-aggregation of the two strains and the microbial adhesion specificity to Caco-2 cells. The co-aggregation of the two strains also contributes to enhancing probiotic potentials of L. paracasei H9.     

Microencapsulation of probiotic cells by means of rennet-gelation of milk proteins

Probiotic cells were microencapsulated in milk protein matrices by means of an enzymatic induced gelation with rennet. Water insoluble, spherical capsules with a volume-based median of 68 ± 5 μm were obtained from a novel developed emulsifying and subsequent internal gelation process. A high encapsulation yield was found due to the encapsulation procedure for Lactobacillus paracasei ssp. paracasei F19 and Bifidobacterium lactis Bb12. After incubation at low pH-values, microencapsulation yielded higher survival rates compared to non-encapsulated probiotic cells. The viable cell numbers of encapsulated Lactobacillus paracasei and Bifidobacterium lactis were 0.8 and 2.8 log units CFU g⁻¹ higher compared to free cells after 90 min incubation at pH 2.5. The improved survival of encapsulated cells can probably be explained by a higher local pH-value within the protein matrix of the capsules caused by the protein buffering capacity, protecting the cells during incubation under simulated gastric conditions at low pH. The study indicates that rennet-induced gelation of skim-milk concentrates for the microencapsulation of probiotic cells can be a suitable alternative to current available technologies, mainly based on ionotrophic gelation of plant-polymer solutions.     

Microencapsulation of Lactobacillus reuteri DSM 17938 Cells Coated in Alginate Beads with Chitosan by Spray Drying to Use as a Probiotic Cell in a Chocolate Soufflé

The main objective of this work was to obtain microencapsulated probiotic cells in order to improve their resistance to heat stress and gastrointestinal conditions. A further aim was to obtain a potentially probiotic chocolate soufflé. Lactobacillus reuteri DSM 17938 cells were microencapsulated by spray drying in alginate matrix and further coated with chitosan. Bacterial survival after exposure to different heat treatments and simulated gastrointestinal conditions were measured to test the microcapsules. They were also dyed by using a LIVE/DEAD^® BacLight? Bacterial Viability Kit and characterized by epifluorescence microscope observation. Furthermore, a potentially chocolate soufflé was prepared using microencapsulated cells. The results indicated that alginate microcapsules did not improve acid tolerance or heat resistance in “in vitro” experiments, while they were able to protect 7% of the Lactobacillus reuteri population during the baking of a chocolate soufflé, compared to a survival rate of 1% of free cells. By contrast, the cells microencapsulated with alginate coated with chitosan showed, compared to free cells, improved acid tolerance, allowing the cell population to remain constant after 3 h in simulated gastric conditions. Moreover, the heat resistance of cells in co-cross-linked microcapsules significantly improved compared to free cells, both in “in vitro” and “in food” experiments. Microencapsulation led to a survival rate of 10% after baking a chocolate soufflé. However, the final level of bacterial cells in the product was too low to consider the chocolate soufflé as a probiotic product.     

Microencapsulated Lactobacillus rhamnosus GG in whey protein and resistant starch matrices: Probiotic survival in fruit juice

This study compared the survival of spray dried microencapsulated Lactobacillus rhamnosus GG (LGG) added into apple juice or citrate buffer (pH 3.5) and stored at 4 or 25 °C over a 5-week period. The LGG was encapsulated in matrices comprising (i) whey protein isolate (WPI) alone, (ii) WPI in combination with a physically-modified resistant starch (RS) at various ratios (4:1, 1:1 and 1:4), or (iii) RS alone. All microencapsulated LGG formulations containing WPI alone or WPI in combination with RS provided better protection to LGG in apple juice or citrate buffer compared to the formulation containing RS alone. We suggest that the protection afforded by formulations containing WPI alone or in combination with RS is due to the ability of WPI to create a buffered microenvironment within the hydrated colloid particle surrounding the embedded LGG, thus isolating the bacteria from the stresses of the low pH external environment.     

Effect of buckwheat flour and oat bran on growth and cell viability of the probiotic strains Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their combination SYNBIO®, in synbiotic fermented milk

Fermented foods have a great significance since they provide and preserve large quantities of nutritious foods in a wide diversity of flavors, aromas and texture, which enrich the human diet. Originally fermented milks were developed as a means of preserving nutrients and are the most representatives of the category. The first aim of this study was to screen the effect of buckwheat flour and oat bran as prebiotics on the production of probiotic fiber-enriched fermented milks, by investigating the kinetics of acidification of buckwheat flour- and oat bran-supplemented milk fermented by Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their 1:1 combination named SYNBIO®. The probiotic strains viability, pH and sensory characteristics of the fermented fiber-enriched milk products, stored at 4 °C for 28 days were also monitored. The results showed that supplementation of whole milk with the tested probiotic strains and the two vegetable substrates results in a significant faster lowering of the pH. Also, the stability of L. rhamnosus IMC 501®, L. paracasei IMC 502® and SYNBIO® during storage at 4 °C for 28 days in buckwheat flour- and oat bran-supplemented samples was remarkably enhanced. The second aim of the study was to develop a new synbiotic product using the best combination of probiotics and prebiotics by promoting better growth and survival and be acceptable to the consumers with high concentration of probiotic strain. This new product was used to conduct a human feeding trial to validate the fermented milk as a carrier for transporting bacterial cells into the human gastrointestinal tract. The probiotic strains were recovered from fecal samples in 40 out of 40 volunteers fed for 4 weeks one portion per day of synbiotic fermented milk carrying about 10⁹ viable cells.     

Effects of Gellan-Based Edible Coating on the Quality of Fresh-Cut Pineapple During Cold Storage

The effects of gellan-based [gellan gum 0.56 % (w/v), glycerol 0.89 % (w/v) and sunflower oil 0.025 % (w/v)] edible coating on the respiration rate, physico-chemical properties and microbiological and sensory quality of fresh-cut pineapple during 16 days of storage (5?±?1 °C, 85?±?10 % RH) were evaluated. Uncoated fresh-cut pineapple was stored under the same condition and served as the control. For cross-linking reaction which was necessary for gel formation of gellan gum, a 2 % (w/v) calcium chloride solution that contained 1 % (w/v) ascorbic acid and 1 % (w/v) citric acid (as antibrowning agents) was used. The results obtained show that the respiration rate and weight loss of gellan-based coated samples were significantly (p?<?0.05) lower than those of the uncoated samples during 16 days of storage at 5 °C. In addition, coated samples significantly (p?<?0.05) maintained the firmness and colour of fresh-cut pineapple during low-temperature storage as compared to uncoated samples. The results obtained in this study also indicate that pH, titratable acidity and total soluble solids of coated and uncoated samples showed little changes during 16 days of storage at 5 °C. Gellan-based formulation did not show any antimicrobial effect, and no significant (p?>?0.05) differences were found among total plate counts and yeast and mould counts for coated and uncoated samples. Total plate counts and yeast and mould counts for coated and uncoated samples reached 10⁶ CFU/g (limit of shelf life acceptance for fruit-based products recommended by the Institute of Food Science and Technology in the UK) after 12 days of storage at 5 °C. In addition, the scores for all sensory characteristics at day 12 were significantly (p?<?0.05) higher in coated samples as compared to control. Therefore, the results obtained in this study indicate that gellan-based edible coating formulation has the potential to maintain the quality of fresh-cut pineapple during low-temperature storage for about 12 days.     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

Microwave-Vacuum Drying of Lactic Acid Bacteria: Influence of Process Parameters on Survival and Acidification Activity

Freeze drying is one important step in downstream processing of probiotics and starter cultures production and requires a long duration of the drying step, which, therefore, often is the overall production bottleneck. Microwave accelerated vacuum drying already showed promising results in terms of product quality for various food products. However, poor information on drying microorganisms by microwaves is available. The aim of this work was to set up a suitable microwave-vacuum drying process for the conservation of lactic acid bacteria and to investigate the optimum process parameters to achieve dried cultures with high survival and activity. The probiotic Lactobacillus paracasei ssp. paracasei F19 was used as model strain. The influence of the process parameters chamber pressure (7–30 mbar), specific microwave power input (1–5 W/g), and maximum product temperature (30–45 °C) on the main quality parameters survival rate, metabolic activity, and water activity of the dried samples were analyzed. Continuous energy input was shown to act detrimentally to the cells due to extreme temperature rise in the second drying stage. Proper temperature regulation could be obtained by pulsed microwave input according to a maximum set temperature. Intermediate microwave power between 3 and 4 W/g, the lowest tested pressure level of 7 mbar and low product temperatures of 30–35 °C, resulted in the highest survival and activity of the bacterial cells. With these results, it could be shown that microwave-vacuum drying appears as a promising alternative drying technique for the preservation of starter and probiotic cultures.     

The Microstructure and Physicochemical Properties of Probiotic Buffalo Yoghurt During Fermentation and Storage: a Comparison with Bovine Yoghurt

The physicochemical and rheological properties of yoghurt made from unstandardised unhomogenised buffalo milk were investigated during fermentation and 28 days of storage and compared to the properties of yoghurt made from homogenised fortified bovine milk. A number of differences observed in the gel network can be linked to differences in milk composition. The microstructure of buffalo yoghurt, as assessed by confocal laser scanning microscopy (CLSM) and cryo scanning electron microscopy (cryo-SEM), was interrupted by large fat globules and featured more serum pores. These fat globules have a lower surface area and bind less protein than the homogenised fat globules in bovine milk. These microstructural differences likely lead to the higher syneresis observed for buffalo yoghurt with an increase from 17.4 % (w/w) to 19.7 % (w/w) in the weight of whey generated at days 1 and 28 of the storage. The higher concentration of total calcium in buffalo milk resulted in the release of more ionic calcium during fermentation. Gelation was also slower but the strength of the two gels was similar due to similar protein and total solids concentrations. Buffalo yoghurt was more viscous, less able to recover from deformation and less Newtonian than bovine yoghurt with a thixotropy of 3,035 Pa.s^?1 measured for buffalo yoghurt at the end of the storage, at least four times higher than the thixotropy of bovine yoghurt. While the titratable acidity, lactose consumption and changes in organic acid concentrations were similar, differences were recorded in the viability of probiotic bacteria with a lower viability of Lactobacillus acidophilus of 5.17 log (CFU/g) recorded for buffalo yoghurt at day 28 of the storage. Our results show that factors other than the total solids content and protein concentration of milk affect the structural properties of yoghurt. They also illustrate the physicochemical reasons why buffalo and bovine yoghurt are reported to have different sensory properties and provide insight into how compositional changes can be used to alter the microstructure and properties of dairy products.