Characteristics Of Yogurt Research Articles

The effect of suweg (Amorphophallus paeoniifolius) flour and incubation temperature on characteristics of yogurt with the addition of Bifidobacterium bifidum as probiotic

Yogurt is a product obtained from fermentation of milk using Lactobacillus bulgaricus and Streptococcus thermophillus bacteria or other suitable lactic acid bacteria. Some beneficial health impacts of yogurt with probiotic were modulating the immune system and supporting the gut’s health by stabilizing the composition of good microflora in the gastrointestinal tract. However, it is important to consider the properties of yoghurt which is affected by its ingredients and bacteria. The purpose of this study was to investigate the effect of suweg flour addition and incubation temperatures on the physicochemical and organoleptic properties of yogurt by using Bifidobacterium bifidum as probiotic for milk fermentation. This study was conducted with 2 factors, the incubation temperature (30 °C, 37 °C, 40 °C) and the percentage of suweg flour addition (2%, 4%, 6%). Physicochemical (pH, total acid, protein content, fat content, reducing sugar) and organoleptic analysis (color, aroma, taste, texture, overall) were investigated in this study. The results of the physicochemical properties of yogurt showed that the addition of suweg flour with different incubation temperatures indicated a significant effect on the total acid, protein, and fat content. In addition, organoleptic evaluation of yogurt suggested that the average panellist’s acceptance of the yogurt was on liked-very liked.

Roles of different packaging materials on the quality and shelf life of yogurt

The main functions of food packaging are providing an essential protection from the environment and from chemical and physical challenges. This study evaluated the effect of different packaging material on the chemical, microbiological and sensory characteristics of yogurt during 14 days of storage. To investigate the potential impact of packaging on yogurt quality, five different types of packaging material used including Glass(A), Aluminum(B), non-identified plastic (C), Polypropylene plastic (PP) (D) and mud(E). The tested materials selected based on the highly uses for local yogurt packaging in Kurdistan region. Analyses of samples were carried out at 1st, 7th and 14th days of storage with in the same yogurt process and storage condition. For chemical tests (pH, titratable acidity and dry matter percentage) determined. In all cases, pH values significantly decreased over storage time (ranged from 4.6 to 4.2), whereas titratable acidity (ranged from 0.40% to 1.11%) and dry matter content gradually increased (ranged from 82.30% to 98%). To investigate the microbiological quality of yogurt samples, total viable count was obtained by inoculating the sample on nutrient agar (NA) and potato Dextrose Agar (PDA). During storage the number of isolates obtained varies from one yogurt sample to the other. After 14th days of storage Sample B has the highest bacteria and fungi count at 106 dilutions. For sensory evaluation a total of 12 members (six male and six female) participated and performed sensory analysis during 14 days storage. The result indicated that the yogurt samples did not show any significant difference among sensory properties in the 1st session. The scores of yogurt sample in aluminum container were slightly higher than others in most of the sensory properties in day 14th of storage.

Improving the Probiotics Viability and Quality Characteristics of Yoghurt Enriched with Barley Bran

Results of current study reported that increase in addition of barley bran in yogurt containing bifidobacterium BB-12, L. bulgaricus and S. thermophillus significantly influence the probiotics numbers. Samples fortified with barley bran has more numbers of probiotics as compare to control samples during storage. Correlation between concentration of barley bran and bifidobacterium was optimistic. Maximum numbers of L. bulgaricus and bifidobacterium were found in yogurt containing 1.5% barley bran. Addition of barley bran increased the acidity percentage of yogurt and decreased viscosity value during 3 weeks of storage. Sensory scores of functional yogurt decreased with increased in barley bran. However sensory score of sample with (0.5% barley bran) did not significantly changed from control sample and number of bifidobacterium bacteria in this sample was higher than minimum standard level (log106 CFU/g) of world health organization (WHO). Syneresis value of control sample was significantly reduced with storage period but yogurt sample enriched with different concentration of barley bran were showed minimum decreased in syneresis percentage of yogurt. Barley bran level 1% can be added to yogurt successfully. Barley bran enrichment increased the color parameters of yogurt during storage this may be due to the results of blueness color of barley bran.

Karakteristik Yoghurt Sinbiotik dengan Penambahan Puree Pisang Mulu Bebe (Musa acuminata) dan Konsentrasi Starter Lactobacillus Bulgaricus yang Berbeda

This study aims to determine the interaction between the different concentrations of starter L. bulgaricus and mulu bebe banana puree on the characteristics of sibiotic yogurt, to determine the effect of different L. bulgaricus.This study aims to determine the interaction between the different concentrations of starter L. bulgaricus and mulu bebe banana puree on the characteristics of synbiotic yogurt, to determine the effect of different L. bulgaricusstarter concentrations on the characteristics of synbiotic yogurt, to determine the effect of different mulu bebe bananas on the characteristics of synbiotic yogurt. This research was conducted in September - January 2021. The test is a chemical test. The purpose of this study was to find out the characteristics of yogurt with the addition of banana puree mulu bebe and different concentrations of L. bulgaricus and look at the interaction influence of each - each treatment of banana puree addition and starter concentration with a fermentation duration of 72 hours. This research is an experimental study using complete randomized design (RAL) factorial, the first factor is the concentration of L. bulgaricus and the second factor of banana puree with 16 levels of perlakua and 3 repeats with each starter concentration L. bulgaricus A1 0, A2 2.5, A3 5, A4 7.5, Puree banana B1 0 ml, B2 2 ml, B3 4 ml, B4 6 ml. If there is a difference in influence between the treatment of each factor, then it is continued with Duncan's test. The observed parameters include: rendemen, pH, water content, ash content, and protein content. The results of this study showed banana puree and L. bulgaricus concentration had a real effect (P<0.05) on rendemen, ash content, protein content. While the water content has no real effect (P>0.05). The interaction between factors A and B in Duncan's advanced test had a significant effect including rendemen, protein levels and ash levels to the characteristics of yogurt.

Effect of Sesame oil and Homogenization Pressure on the Physicochemical, Qualitative and Microbial Characteristics of Yogurt

Effect of Sesame oil and Homogenization Pressure on the Physicochemical, Qualitative and Microbial Characteristics of Yogurt

In vitro digestion of sodium alginate/pectin co-encapsulated Lactobacillus bulgaricus and its application in yogurt bilayer beads

The purpose of this study was to prepare sodium alginate (SA)/pectin (PE) hydrogel microspheres using the extrusion method to encapsulate Lactobacillus bulgaricus. Microscopic observation showed that the beads were spherical with a smooth and uniform surface. For microspheres with a diameter range of 140–156 μm, the encapsulation efficiency reached 85.67%. After simulating saliva, gastric juice, and intestinal juice, the activity of the microcapsules was estimated to be 5.78 × 104 log colony forming unit (CFU)/mL. These data show that the use of SA and PE encapsulated probiotics exhibit enhanced viability. In addition, double-layer beads containing probiotic microspheres and yogurt were prepared, and physical and chemical analysis was performed using scanning electron microscopy, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Texture and sensory property analysis revealed that the beads had good elasticity, chewiness, and high commercial value. Collectively, these findings indicate that SA and PE can be used for the encapsulation, protection, and gastrointestinal delivery of probiotics. Moreover, these microcapsules exhibit good stability in vitro and improve yogurt characteristics by increasing the survival rate of encapsulated probiotics, thus demonstrating their commercial application potential.

Lacticaseibacillus casei 01 improves the sensory characteristics in goat milk yogurt added with xique-xique (Pilosocereus gounellei) jam through changes in volatiles concentration

This study aimed to evaluate the impact of adding Lacticaseibacillus casei (0.2 g/L) and xique-xique jam (10 g/100 g) to goat milk yogurt during storage (1, 14, and 28 days). The yogurts were characterized regarding sugar profiles, organic acids, volatile compounds, and sensory attributes using Preferred Attribute Elicitation (PAE) methodology. Three formulations were prepared: (CY) control (with sucrose), (XY) with xique-xique jam, and (PY) with xique-xique jam and L. casei. Results showed that XY exhibited higher sugar content, but organic acid and volatile compound profiles were similar to CY. PY showed lower sugar content (galactose and glucose), higher organic acid content (lactic acid and propionic acid), and higher volatile compounds concentration. It presented improved sensory characteristics, with higher herbaceous aroma and flavor, dairy aroma, sweet aroma and taste, and typical aroma and flavor. Furthermore, it had a lower goat aroma and flavor and cheese aroma. There was an increase in some volatile compounds in CY and XY during storage, while PY had a peak at 14 days. Results suggest that probiotic addition may improve the volatilomic, fermentation profile, and sensory characteristics of yogurts added with xique-xique jam. Furthermore, PAE could be used to characterize the aroma and flavor attributes.

PENGARUH PENAMBAHAN SUSU WHEY BUBUK TERHADAP TOTAL PADATAN TERLARUT DAN KARAKTERISTIK YOGHURT YANG DIHASILKAN

Yoghurt is a product of milk diversification that utilizes milk preservation technology by means of fermentation. Yogurt is a fermented beverage with the addition of Streptococcus thermophillus and Lactobacillus bulgaricus inoculum.The purpose of the study was to determine the effect of increasing the concentration of milk whey powder on the characteristics of yogurt, while the aim was to determine the right concentration of milk whey powder to produce yogurt with good characteristics. The research will be carried out from January to Maret 2021 in Laboratory Food Technology at the Faculty of Agriculture Ma’soem University. The design used in this experiment was a Randomized Block Design consisting of 6 (six) treatments and carried out 4 (four) replications. Treatment A: Addition of Concentration of Milk Whey Powder 5.75%, Treatment B: Addition of Concentration of Milk Whey Powder 6.00% , Treatment Addition of Concentration of Milk Whey Powder 6.25%, Treatment D: Addition of Concentration of Milk Whey Powder 6.50%, Treatment E: Addition of Concentration of Milk Whey Powder 6.75 % , Treatment F: Addition of Concentration of Milk Whey Powder 7.00%.Observations of experimental results have included chemical analysis of total dissolved solids, microbiological analysis of coliforms, and organoleptic analysis of the level of preference for texture, aroma and taste of the resulting yogurt. The results showed that the addition of milk whey powder concentration of 6.50% (D) resulted in a good total dissolved solids of 14.50%. In organoleptic testing of 25 panelists, the level of preference for texture: 3.9 , aroma: 4.45 and taste: 4.73 to the characteristics of the resulting Yoghurt. The results of microbiological testing expressed in Coliform <10. The yogurt from this experiment has also met the quality requirements of SNI 01-2891-1992.

Co-Fermentation by Lactobacillus brevis B7 Improves the Antioxidant and Immunomodulatory Activities of Hydroponic Ginseng-Fortified Yogurt.

The development of convenient and accessible health-functional foods has become an area of increased interest in recent years. Probiotics, ginseng, and yogurts have been recognized as representative nutraceutical products. To improve the functionality of yogurts, co-fermentation was performed during yogurt preparation. Four kinds of yogurt were prepared using a combination of probiotic Lactobacillus brevis B7 and hydroponic ginseng based on plain yogurt. The fundamental characteristics of yogurts, including pH, titratable acidity, microbial counts, color, and physicochemical properties, were determined. To assess functionality, four different antioxidant assays and real-time PCR analysis using RAW 264.7 cells were performed. Finally, sensory evaluation was conducted to evaluate customer preference. Hydroponic ginseng supplementation influenced pH, solid content, lightness, and yellowness. However, probiotic supplementation did not affect most factors except pH. In functionality analysis, the yogurt co-fermented with probiotics and ginseng showed the highest antioxidant activity and gene expression levels of the immune-related factors TNF-α and iNOS in RAW 264.7 cells. Although ginseng supplementation received poor acceptance because of its color and flavor, these attempts were considered beneficial despite the risk. Overall, co-fermentation within a short yogurt preparation time presented the potential for improvement of functionality. These findings suggest a range of feasibility for the development of attractive nutraceutical products.

Effect of the Addition of Whole and Milled Flaxseed on the Quality Characteristics of Yogurt.

The present study aimed to analyze the effect of the addition of whole and milled flaxseed on the quality characteristics of yogurt. In the first stage of the research, the optimal dose of flaxseed was determined. In the second stage of the research, it was assessed whether the selected qualities of yogurt were affected by the form of flaxseed (whole or milled) and the time of addition (before or after fermentation). The yogurts obtained were stored at 5 °C for 21 days, and the changes in active acidity, apparent viscosity, syneresis, and the number of yogurt bacteria were determined. The results of the second stage of the study were subjected to two-way analysis of variance (ANOVA) (p < 0.05). The study showed that the addition of milled flaxseed to yogurts in the amount of 1% was optimal. Time and form of flaxseed supplementation significantly influenced the changes in active acidity, apparent viscosity, and syneresis in the tested yogurts. The addition of flaxseed did not significantly change the content of yogurt bacteria. The results indicate that to achieve increased apparent viscosity and reduced syneresis, it is more advantageous to use milled flaxseed rather than whole flaxseed.

Effect of a microencapsulated synbiotic product on microbiology, microstructure, textural and rheological properties of stirred yogurt

In this study, synbiotic microcapsules composed of Lactobacillus paracasei (Lacticaseibacillus paracasei) and lactitol were added into milk to prepare probiotic stirred yogurt. The number of lactic acid bacteria, pH, water holding capacity (WHC), texture, rheological properties and microstructure were measured during 4 °C storage to evaluate the characteristics of yogurt. Yogurt containg microcapsules had an increase in the number of lactic acid bacteria and a lower post-acidification when compared to the yogurt containg free cells of L. paracasei during storage. Addition of microcapsules resulted in a product, which observed a higher WHC, cohesiveness and rheological properties. Scanning electron microscope observed that the addition of microcapsules reduced the casein aggregates and pores of the yogurt, leading to a tighter microstructure. In general, the addition of encapsulated L. paracasei could improve the texture performance of yogurt. However, in addition to the increase of probiotics, there was no significant difference between the yogurt with probiotics and synbiotic microcapsules.

CHARACTERISTICS OF THE YOGURT BEING INCUBATED IN GREEN COCONUT SHELL (Cocos nucifera L. var. viridis Hassk)

&#x0D; &#x0D; &#x0D; The study aims to identify characteristics of the yogurt being incubated in green coconut shell (Cocos nucifera L. var. viridis Hassk). It was conducted in March 2020 at the Laboratory of Animal Product Technology and Mic- robiology Faculty of Animal Science, Udayana University. This studies used a Complete Random Design (CDR) with three treatments and five replications. The three treatments were incubated in a jar container (control) (P0), incubated in green coconut shell nonflesh (P1) and incubated in green coconut shell with flesh (P2). The variables observed were lactoce level, fat level, protein level and pH value. The results of this study have shown that yogurt’s characteristic indicated lactose and protein levels was not significantly different (P&gt;0,05) in all treatments, but P2 fat levels was higher significantly (P&lt;0,05) different than P1 and P0. pH values was not significantly different (P&gt;0,05) with P1 and significantly different (P&lt;0,05) with P0. Conclusing in this study that the characteristics of yogurt incubated in green coconut shell getting good results at lactose level 2,32,42%; fat level 10,60-12,50%; pro- tein level 4,80-4,90%; and value pH 4,14-4,24%.&#x0D; &#x0D; &#x0D;

The impact of storage on the sensory, viscosity and chemical characteristics of yogurt fortified with oat β-glucan

Oat β-glucan has the potential of a functional additive to yogurt, however, texture analysis and chemical characteristics during storage of yogurt with the addition of this additive require more systematic research, which determines the relevance of the study. The aim of the research work was to analyze the feasibility of enriching yogurt with 0.3% oat β-glucan. A number of methods for obtaining new knowledge in the direction of developing healthy food products were used. It was found that yogurt with the addition of 0.3% oat β-glucan had water-holding capacity. All pH values ranged from 4.18 to 4.28, which are within the normal ranges for set-type yogurts. A higher viscosity of the experimental sample of yogurt compared to the control was established, and the highest values were 58560±2120 cp at 21 days for yogurt with the addition of 0.3% oat β-glucan. The viability of probiotic bacteria in yogurts was examined. During the whole storage period, the content of probiotics decreased, but yogurt with the addition of 0.3% oat β-glucan contained significantly more live probiotic bacteria compared to the control. The viability of probiotic bacteria of 0.3% oat β-glucan yogurt at 14 d (3.18±0.2×107 CFU/mL) was only slightly lower than that of control yogurt at 1 d (3.45±0.3×107 CFU/mL). This fully demonstrates that the addition of 0.3% oat β-glucan has a protective effect on probiotics in yogurt, which will be beneficial for human health. It was found that the addition of 0.3% oat β-glucan led to a decrease in adhesiveness, but an increase in hardness and stickiness during storage. The results of the sensory evaluation showed the highest acceptability values of 86.49 for 21 days of storage of yogurt with the addition of 0.3% oat β-glucan. The practical value of the research work lies in the developed yogurt containing 0.3% oat β-glucan being possibly to use as an innovative healthy dairy product

Probiotic yogurt and cheese from ultrafiltered milk: Sensory quality and viability of free‐living and spray dried Lactiplantibacillus plantarum 564 and Lactiplantibacillus plantarum 299v

The effect of free-living and spray-dried probiotic bacteria, Lactiplantibacillus plantarum 564 and Lactiplantibacillus plantarum 299v, on sensory characteristics of yogurt and cheese made from ultrafiltered (UF) milk, as well as their viability during storage, was investigated. Bacterial counts of free-living and spray-dried probiotic cells in yogurt remained above 7.43 log cfu/ml after 21 days, whereas in UF cheese, cell count was 8.84 log cfu/g after 56 days of storage. Starter bacteria count maintained above 7.6 log cfu/ml for yogurt and 8.5 log cfu/g for UF cheese during storage, while pH values did not significantly differ from control (without probiotic) and probiotic variants. Sensory evaluation showed that probiotic yogurt and UF cheese were evaluated with very high marks. The long-term viability of spray-dried probiotic L. plantarum 564 and L. plantarum 299v in UF cheeses indicates that these products could be successfully used as probiotic carriers. Novelty impact statement Spray drying probiotic cells showed significantly higher viability compare to free-living cells in yogurt. Potential probiotic bacteria Lactiplantibacillus plantarum 564 maintained at high level in ultrafiltered (UF) cheese. Probiotic yogurts and UF cheeses were evaluated with excellent sensory quality.

QUALITY ASSESSMENT OF YOGURT ENRICHED WITH OAT AND CHICKPEA POWDERS AS SOURCE OF DIETARY FIBERS

The aim of this study was to evaluate the effect of addition of oat and chickpea powders on the rheological, physicochemical and sensory characteristics of yogurt. Yogurt was fortified with oat and chickpea powders at ratios of 1, 2 and 3% of each. Yogurt was stored at 5 ±2˚C and analyzed when fresh and after 5, 10 and 15 days of storage. Results showed that:Control yogurt had the lowest total solids (TS), fat, protein,ash and fibers contents compared with fortified yogurt treatments. The TS, fat ,protein, ash and fibers contents of yogurt containing oat and chickpea powders at different concentrations increased gradually by increasing the percentage added, Addition of oat and chickpea powders at different concentrations increased the pH in yogurt. Whereas, titratable acidity decreased with increased fortification ratio. Fortification of yogurt with oat and chickpea powders at different concentrations significantly decreased whey syneresis and increased viscosity compared with control yogurt and this increasing was proportional to the fortification ratio. Addition of oat and chickpea powders at different concentrations significantly increased phenolic contents and antioxidant activity of yogurt treatments and these increments were proportional to the fortification ratio. Yogurt treatments fortified with oat and chickpea powders at different concentrations had the lowest counts of total bacteria, yeast and moulds,Streptococcus salivarius subsp.thermophilus andLactobacillus delbruekii subsp. bulgaricuscounts. Total bacteria, yeast and moulds,Streptococcus salivarius subsp. thermophilus and Lactobacillus delbruekii subsp. bulgaricuscounts decreased with increasing the fortification ratio.Control yogurt had the lowest sensory evaluations values. Addition of oat and chickpea powders improved the organoleptic properties of fortified yogurt; the highest mean value was related to sample containing 3% oat powder.

COMPARISON OF THE QUALITY OF THREE TYPES OF YOGURT. THE IMPACT OF TAPIOCA POWDER ON THE CHARACTERISTICS OF YOGURT

This research presents a comparison between three types of yogurt: classic yogurt without addition, yogurt with added skimmed milk powder (the most common yogurt additive) and yogurt with tapioca. The aim of the research is to identify whether there are differences between these three products and what is the impact of tapioca powder on the characteristics of yogurt. Experimental determinations were performed such as: sensory analysis, textural analysis, analysis of physical parameters (acidity, lactose content, syneresis).

Selection of potential probiotics with cholesterol-lowering properties for probiotic yoghurt production.

From 61 lactic acid bacteria (LAB) isolates, three had good cholesterol-lowering properties, with Limosilactobacillus fermentum KUB-D18 having the highest cholesterol assimilation (68.75%) (51 µg/109 CFU). In addition, Lactiplantibacillus pentosus HM04-25 and L. pentosus HM04-3 had the two highest levels of bile salt hydrolase (BSH) activity (22.60 and 21.45 U/mL, respectively). These three strains could resist four antibiotics (aztreonam, vancomycin, teicoplanin, and nalidixic). However, fortunately, they contained no mobile antibiotic resistance genes. To evaluate the influence of probiotic strains in yoghurt production, L. fermentum KUB-D18, L. pentosus HM04-25, or L. pentosus HM04-3 were simultaneously cultured with commercial yoghurt starter (YF-L812) and incubated at 43 °C for 6 h. During yoghurt fermentation, the total bacteria in the yoghurt tended to increase from 7.39 to 8.90 log CFU/mL. The growth rates of two probiotic strains (L. pentosus HM04-25 and L. pentosus HM04-3) were stable at 6.06 to 6.62 log CFU/mL. Only the rate for L. fermentum KUB-D18 increased (to 7.5 log CFU/mL). These three probiotics did not affect the physical characteristics of yoghurt. The total soluble solids, pH, and titratable acidity values of the probiotic yoghurts were similar to the control yoghurt at 30Brix, 4.91, and 0.90%, respectively. The firmness values of the probiotic yoghurts and the control were not significantly different (p > 0.05). Differentiation of the appearance of color, odor, flavor, and texture between the control yoghurt and the probiotic yoghurts was investigated using 56 volunteers and no significant differences were identified. Additionally, sensory evolution revealed that the acceptability of the probiotic yoghurts was higher than for the control (p ≤ 0.05). Therefore, the three probiotic strains with cholesterol-lowering properties had potential in future yoghurt production.

STUDY OF PROPERTIES OF YOGHURTS MADE USING VIVO STARTER CULTURES

The article presents the results of experimental studies of qualitative indicators of milk and fermented milk products (yoghurts) made using VIVO starter cultures. VIVO starter cultures contain thermophilic lactic acid bacteria Streptococcus thermophilus, Lactobacillus delbrueckii ssp., Lactobacillus acidophilus and others.&#x0D; The determination of organoleptic and physico-chemical parameters of cow's milk and dairy products based on it was carried out according to generally accepted methods. During the organoleptic evaluation of milk and lactic acid products, the appearance and texture, smell, taste and color of milk were examined. Determination of active acidity was carried out in accordance with GOST 26781. Titratable acidity in degrees Turner was determined according to GOST 3624. The content of fat, protein, dry matter was determined according to GOST 2661: 2010.&#x0D; A study was made of the organoleptic characteristics of yogurts obtained by fermentation by using of VIVO starter cultures. The high activity of VIVO starter cultures was established, the products on the basis of which have a pleasant taste characteristic of these products.&#x0D; The results of physico-chemical analysis of yogurt samples obtained by using of VIVO starter cultures confirmed their compliance with DSTU 4343: 2004.&#x0D; Lactic acid products made with VIVO sourdough are functional products. It is recommended to use yogurts based on VIVO starter cultures to restore intestinal microflora, normalize digestion, strengthen immunity, and reduce the risk of colds and SARS.

Quality characteristics of yogurts fermented with short-chain fatty acid-producing probiotics and their effects on mucin production and probiotic adhesion onto human colon epithelial cells

Probiotics can ferment nondigestible carbohydrates and produce short-chain fatty acids (SCFA; acetate, propionate, and butyrate) in the human colon. In this study, the levels of SCFA were determined in the following yogurts fermented with different combinations of probiotics: (1) cocultures of Streptococcus thermophilus and Lactobacillus bulgaricus (control, C); (2) S. thermophilus, L. bulgaricus, and Bifidobacterium bifidum (C-Bb); (3) S. thermophilus, L. bulgaricus, and Lactobacillus acidophilus (C-La); and (4) S. thermophilus, L. bulgaricus, and Lactobacillus gasseri (C-Lg). Results showed that the acetate levels were significantly higher in C-Bb, C-La, and C-Lg yogurts than in C yogurt. Fermentation and physicochemical characteristics of all yogurts were identical. Treatment of mucus-secreting colon epithelial cells (HT29-MTX) with C-Bb, C-La, and C-Lg yogurt supernatants resulted in an increase in the expression of MUC2 and CDX2 and the production of mucin proteins. The adhesion of probiotics onto HT29-MTX cells increased following treatment with C-Bb, C-La, and C-Lg yogurt supernatants. Our data suggest that a yogurt diet rich in acetate improves the protective function of the intestinal epithelium.

The effect of green tea polyphenols addition on the physicochemical, microbiological and bioactive characteristics of yogurt

PurposeThe purpose of this paper is to evaluate the effect of green tea polyphenols addition on physicochemical, microbiological and bioactive characteristics of yogurt.Design/methodology/approachTwo incorporation methods of polyphenols were evaluated: direct addition or incorporated within protein particles of whey protein concentrate and gelatin. During yogurt’s shelf life, structure characteristics (water holding capacity, textural and rheological parameters), lactic acid bacteria (LAB) viability and polyphenols antioxidant activity were analyzed. Also, polyphenol bioaccesibility afterin vitrodigestion was evaluated.FindingsPolyphenols addition (by the two methods used) did not affect the dynamics of the fermentation process, nor the LAB viability during storage. The color parametera* for the yogurts with the highest polyphenol concentrations showed positive values (tending to red), but not visible to the naked eye. Because of the ability of polyphenols to interact with milk proteins, yogurts with polyphenols presented higher values in firmness and cohesiveness with respect to the control. Additionally, the incorporation of polyphenols in protein particles increased even more these parameters because of the higher protein content of these formulations. After simulated digestion, a high polyphenol bioaccesibility was observed, and the antioxidant activity was retained, which could be explained by the “protector” effect of the milk matrix.Practical implicationsYogurt supplementation with green tea polyphenols is feasible for the development of functional food. However, the use of protein particles would not provide an extra benefit because milk proteins already act as protective molecules of polyphenols.Originality/valueThis study shows not only the physico-chemical implications of including polyphenols in yogurt but also their bioaccesibility after anin vitrodigestion, revealing a suitable manner for delivery of antioxidants in a dairy product like yogurt.