Microencapsulation of flaxseed oil in pea protein-gum arabic complex coacervates delays lipid digestion in liquid yoghurt.

Flaxseed oil coacervates were produced by complex coacervation using soluble pea protein and gum arabic as shell materials, followed by either spray or electrostatic spray drying and their incorporation to yoghurt. Three yoghurt formulations were prepared: yoghurt with spray-dried microcapsules (Y-SD); with electrospray-dried microcapsules (Y-ES); with the encapsulation ingredients added in free form (Y). The standardised semi-dynamicin vitrodigestion method (INFOGEST) was employed to study the food digestion. The structure was analysed by confocal laser scanning microscopy and particle size distribution. Protein and lipid digestion were monitored by cumulated protein/free NH2 release and cumulated free fatty acids release, respectively. Stable microcapsules were observed during gastric digestion, but there was no significant difference in protein release/hydrolysis among samples until 55 min of gastric digestion. Formulation Y showed less protein release after 74 min (40.46 %) due to the free SPP being available and positively charged at pH 2-4, resulting in interactions with other constituents of the yoghurt, which delayed its release/hydrolysis. The total release of protein and free NH2 by the end of intestinal digestions ranged between 46.56-61.15 % and 0.83-1.57 µmol/g protein, respectively. A higher release of free fatty acids from formulation Y occurred at the end of intestinal digestion, implying that coacervates promoted the delayed release of encapsulated oil. In summary, incorporating protein-polysaccharides-based coacervates in yoghurt enabled the delay of the digestion of encapsulated lipids but accelerated the digestion of protein, suggesting a promising approach for various food applications.

Preparation of liquid yogurt in the presence of pectin and its formation mechanism.

We had previously observed that adding pectin into milk before fermentation inhibited gelation of yogurt but did not affect the pH. Thus, this work aimed to prepare such liquid yogurt and clarify its formation mechanism. It was found that liquid yogurt was obtained in the presence of 0.10%-0.20% pectin. However, at lower or higher pectin concentrations, yogurt was gelled. Confocal laser scanning microscopy analysis demonstrated that 0.10%-0.20% pectin induced milk protein aggregating into separated particles rather than a continuous network, which explained why liquid yogurt was formed. Moreover, adding 0.10%-0.20% pectin into the casein micelle suspension induced aggregation of casein micelles at pH 6.8. After pH decreased to 4.3, casein micelles showed more aggregation but they were still separated particles, which was the same in the corresponding yogurt samples. These results suggested that pectin changed the aggregation mode of casein micelles and induced formation of liquid yogurt.

Cholesterol and Its Oxidation Derivatives Content in Market Dairy Products.

Cholesterol oxidation products (COPs) are contaminants of food of animal origin. Increased levels of these compounds in the human body are associated with an increased risk of many non-communicable diseases. Dairy products are mentioned among the main sources of these compounds in the diet. The objective of this study was to evaluate the contents of cholesterol and its oxidized derivatives in eleven groups of dairy products, willingly consumed in European countries. The levels of COPs were determined by applying the GC-TOF/MS method. In the tested products, cholesterol and its oxidation derivatives, such as 7-ketocholesterol, 7α-hydroxycholesterol, 7ß-hydroxycholesterol, 5,6ß-epoxycholesterol and 5,6α-epoxycholesterol, were determined. The studied dairy products differed in their contents and profiles of oxysterols. The highest contents of COPs were found in cheese with internal mold (13.8 ± 2.5 mg kg-1) and Cheddar (11.7 ± 3.5 mg kg-1), while the lowest levels were detected in yoghurt (0.94 ± 0.30 mg kg-1) and kefir (0.57 ± 0.11 mg kg-1). 7-ketocholesterol and 5,6ß-epoxycholesterol were the dominant oxysterols. The ratio of oxidized derivatives to total cholesterol was on average 1.7%. Our results confirmed that dairy products are an important dietary source of COPs. Their levels should be monitored in dairy products to provide the best health quality.

A unique implementation of Hantzsch reaction for determination of natamycin in Yoghurt: Hyphenated with Box-Behnken-design for optimization.

This study aims to develop a novel and selective method for the detection of natamycin (E235) in yoghurt. The suggested method adopts an application of Hantzsch reaction to turn on the fluorescence behavior of natamycin (blue fluorescence), allowing its sensitive and selective determination in yoghurt samples without any overlapping at 485 nm. The originality of the research lies in the fact that this application takes place for the first time, also the detection (LOD) and quantification (LOQ) limits were very low (0.02 and 0.06µg mL-1, respectively) with a linear concentration range of 0.1-1.0 µgmL-1. Moreover, the developed method was employed for the detection of E235 in yoghurt sample with a good recoveries (98.80 ± 1.20-99.20 ± 1.15 (%), over a concentration range of 0.5-1.0 µgmL-1, (LOD = 0.04 and LOQ = 0.12 µgmL-1). Furthermore, the specificity and convenient application of our intended method is an attempt to determine E235 in milk anddairy products with easily followable steps.

Combining thermosonication microstress and pineapple peel extract addition to achieve quality and post-acidification control in yogurt fermentation.

This work investigated the effects of the combined use of thermosonication-preconditioned lactic acid bacteria (LAB) with the addition of ultrasound-assisted pineapple peel extracts (UU group) on the post-acidification potential, physicochemical and functional qualities of yogurt products, aimed at achieving prolonged preservation and enhancing functional attributes. Accordingly, the physical-chemical features, adhesion properties, and sensory profiles, acidification kinetics, the contents of major organic acids, and antioxidant activities of the differentially processed yogurts during refrigeration were characterized. Following a 14-day chilled storage process, UU group exhibited acidity levels of 0.5-2 oT lower than the control group and a higher lactose content of 0.07 mg/ml as well as unmodified adhesion potential, indicating that the proposed combination method efficiently inhibited post-acidification and delayed lactose metabolism without leading to significant impairment of the probiotic properties. The results of physicochemical analysis showed no significant changes in viscosity, hardness, and color of yogurt. Furthermore, the total phenolic content of UU-treated samples was 98 µg/mL, 1.78 times higher than that of the control, corresponding with the significantly lower IC50 values of DPPH and ABTS radical scavenging activities of the UU group than those of the control group. Observations by fluorescence inverted microscopy demonstrated the obvious adhesion phenomenon with no significant difference found among differentially prepared yogurts. The results of targeted metabolomics indicated the proposed combination strategy significantly modified the microbial metabolism, leading to the delayed utilization of lactose and the inhibited conversion into glucose during post-fermentation, as well as the decreased lactic acid production and a notable shift towards the formation of relatively weak acids such as succinic acid and citric acid. This study confirmed the feasibility of thermosonication-preconditioned LAB inocula, in combination with the use of natural active components from fruit processing byproducts, to alleviate post-acidification in yogurt and to enhance its antioxidant activities as well as simultaneously maintaining sensory features.

Evaluation of lupine seeds (Lupinus albus L.) neutral extract as a texture improver in low-fat yogurt production.

Aqueous lupine seeds (Lupinus albus L.) extracts were evaluated as a natural fat substitute in low-fat yogurt production. Thus, the chemical composition, particle size, molecular weight, total phenolic (TPC), and total flavonoids (TFC) of the selected extract were estimated. Also, the antimicrobial activity and antioxidant capacity of selected extract were investigated. Yogurt with neutral lupine extract (NeLP) had the highest all sensorial attributes compared to other extracts. Also, the incorporation of NeLP during low-fat yogurt processing increased the solid content, and viscosity, as well as improved the textural profile and sensorial attributes without any negative effect on the yogurt's color. SEM micrographs of NeLP-yogurt microstructure showed a matrix characterized by large fused casein micelles clusters with comparatively lower porosity compared to control yogurt (without NeLP). The chemical composition of NeLP indicated that the major sugar constituents are glucose and galactose with different molar fractions. The molecular weight of NeLP is 460.5 kDa with a particle size of 1519.9 nm. Also, IC50 of NeLP is 0.589 mg/ml, while TPC and TFC are 7.17, and 0.0137 g/100 g sample, respectively. Hence, lupine neutral extract (0.25%) could be used as a fat replacer or texture improver ingredient in such low-fat yogurt which led to improved its characteristics without any negative defect during 7 days at 5 °C.

Effect of probiotic incorporation on physicochemical attributes of yogurt during storage and influence on cholesterol assimilation.

This study aimed to evaluate the incorporation effect of probiotic culture (Lactobacillus acidophilus) in buffalo milk yogurt on stability and microbial survival rate during storage. In addition, the influence of probiotic culture on blood lipid profiles was investigated for a period of 6 weeks. Yogurt was prepared with buffalo milk with different probiotic concentrations (0, 100, and 50%) and administered to subjects at 300 g/day. All treatments showed a significant difference (p < 0.05) in acidity and pH during storage for 21 days at refrigeration temperature, while treatment with 100% probiotic culture (G2) was most prominent. Physicochemical analysis demonstrated a maximum pH decline of 0.60 in G2, followed by 0.56 in the mix cultured (G3). However, increasing trend was observed in acidity, with highest increment of 0.89% followed by 0.54% in G2 and G3, respectively. Storage study of total viable count demonstrated the reduction in the enumeration of microbial population owing to the production of organic acids, while L. acidophilus had a high survival rate of 5.25 log 10 CFU/g. Probiotic culture produced significant results in the lipid profile of subjects. Treatments containing probiotic bacteria G2 and G3 showed the lowest total cholesterol (183.57 and 182.85 mg/dL) and low density lipoproteins (LDL) (105.80 106.40 mg/dL), respectively. In terms of high density lipoproteins (HDL), G2 showed a highest increment of 49.82 mg/dL. Results of our study revealed that consumption of probiotic yogurt is beneficial for human health by improvement of blood lipid profiles and reduces cardiovascular patient's percentage around the globe. PRACTICAL APPLICATION: Experimental investigation of the effect of probiotic culture addition on the stability of buffalo milk yogurt. Assessment of the potential of Lactobacillus acidophilus on blood lipid profiles.

Buffalo yogurt fermented with commercial starter and Lactobacillus plantarum originating from breast milk lowered blood pressure in pregnant hypertensive rats.

Nutritional therapy, which may have advantages over medication, is being investigated as a novel treatment for pregnancy-induced hypertension. Several studies have shown that probiotic yogurt supplementation during pregnancy has beneficial effects on maternal and fetal health. In this study, fermented buffalo milk was produced with yogurt culture and Lactobacillus plantarum B, a probiotic isolated from healthy breast milk with high angiotensin-converting enzyme inhibitory activity. The fermentation conditions under which the angiotensin-converting enzyme (ACE) inhibitory activity reached 84.51% were optimized by the response surface method as follows: 2 × 106 cfu/mL of L. plantarum B, yogurt culture 2.5 × 105 cfu/mL, and 8 h at 37°C. The distribution of ACE inhibitory peptides from fermented buffalo milk and fermented cow milk were further analyzed by liquid chromatography-mass spectrometry. By searching according to the structural features of ACE inhibitory peptides, 29 and 11 peptides containing ACE inhibitory peptide features were found in fermented buffalo milk and fermented cow milk, respectively. To investigate the in vivo antihypertensive activity of fermented buffalo milk, 18 pregnant rats were divided into 3 groups (n = 6 in each group) and administered 10 mL of normal saline, yogurt (20 mg/kg), or labetalol hydrochloride (4 mg/kg) daily from the beginning of pregnancy to parturition. To induce hypertension, methyl nitrosoarginine (125 mg/kg) was injected subcutaneously every day from d 15 of pregnancy to the day of delivery. Blood pressure was not significantly changed in the yogurt and labetalol groups after induction of hypertension and was lower compared with the normal saline group, but there was no difference between the yogurt and labetalol groups. This implied that the buffalo yogurt had a preventive and antihypertensive effect in the pregnancy-induced hypertensive rat model. Further studies to determine the mechanism of action, as well as a randomized control trial, are warranted.

Optimizing the Production of Probiotic Yogurt as a New Functional Food for Diabetics with Favorable Sensory Properties Using the Response Surface Methodology.

This study aimed to optimize the processing of probiotic yogurt supplemented with cumin essential oil (CEO), vitamin C, D3 (Vit D), and reduction of fermentation time using response surface methodology as a new functional food for diabetics with desirable sensory properties. The central composite design (CCD) was used to analyze the effect of these independent variables on the growth of the Lactobacillus plantarum A7 (LA7), starter culture, and overall acceptability. Differences between treatments were analyzed. The data were evaluated by analysis of variance at the significance level of 0.05. The effective concentration of CEO and fermentation time had the significant effect on the Lactobacillus plantarum A7 (LA7) number. Variance analysis and three-dimensional graphs show that almost the only effective factor on the overall acceptability of probiotic yogurt containing essential oil and vitamin D3 was CEO. According to the obtained data from the analysis, the optimal amount of independent variables for probiotic yogurt formulation such as CEO, D3, and fermentation time was 0.02% (v/v), 400 IU, and 9 h, respectively. This functional product can be considered an efficient food to reduce or eliminate the complications of diabetes.

Metataxonomic Sequencing to Assess Microbial Safety of Buffalo Yogurts in Amasra Region.

Interest in the "microbiota" of dairy products and studies on this subject is increasing day by day. In this study, homemade buffalo yogurt was collected from five different local producers in Amasra province, and their microbiota was evaluated by next-generation sequencing. Salmonella enterica was found in all yogurts (1.2-3.17%). Klebsiella pneumoniae was found to be 1.12% and 5.15% in two of the samples. Staphylococcus aureus was found to be 3.17% in only a single sample. The presence of these potentially pathogenic bacteria suggests that more attention should be paid to hygiene rules during homemade production, processing, and distribution of these products being offered for sale in public markets. These yogurt products can potentially carry risks of contamination and should be periodically checked by the relevant authorities.

Machine learning based classification of yogurt aroma types with flavoromics.

Traditional sensory evaluation, relying on human assessors, is vulnerable to subjective error and lacks automation. Nonetheless, the complexity of human sensation makes it challenging to develop a computational method in place of human sensory evaluation. To tackle this challenge, this study constructed logistic regression classification models that could predict yogurt aroma types based on aroma-active compound concentrations with high classification accuracy (AUC ROC > 0.8). Furthermore, indicator compounds discovered from feature importance analysis of classification models led to the derivation of classification criteria of yogurt aroma types. Through constructing and analyzing machine learning models on yogurt aroma types, this study provides an automated pipeline to monitor sensory properties of yogurts.

A comparison of the quality of plain yogurt and its analog made from coconut flesh extract.

The aim of this study was to compare the quality of plain yogurt made from cow milk (n = 10) and its plant-based analog made from coconut flesh extract (n = 14). Coconut yogurt alternatives were divided into 2 experimental groups based on differences in their color, which were noted after the packages had been opened. The first group included products with a typical white color (n = 8), and the second group comprised products with a grayish pink color (n = 6) that developed as a result of oxidative processes. In comparison with its plant-based analog, plain yogurt was characterized by higher values of lightness (L*), yellowness (b*) and chroma (C*), higher titratable acidity, a higher content of retinol and α-tocopherol, higher nutritional value of fat, and lower values of water-holding capacity (WHC) and redness (a*). Plain yogurt had lower volatile acidity than its plant-based analog with a grayish pink color. A comparison of yogurt analogs with different colors revealed that the product with a grayish pink color was characterized by a lower value of L*, and higher values of a*, b*, C*, and pH. An analysis of its fatty acid profile demonstrated that it also had a higher proportion of C14:0 and C18:1 cis-9; higher total monounsaturated fatty acids content; a lower proportion of C10:0, C12:0, and C18:2; a lower total content of polyunsaturated fatty acids (PUFA) and essential fatty acids; and a lower ratio of PUFA to saturated fatty acids. The yogurt analog with a grayish pink color had a lower total content of tocopherol isoforms than the remaining products. The yogurt analog with a white color had the highest WHC and γ-tocopherol content. Consumers should be aware of the fact that coconut yogurt alternatives may have nonstandard quality attributes. The differences between such products and yogurt made from cow milk should be explicitly communicated to consumers so that they could make informed purchasing decisions.

Enhancing the functionality of plant-based Yogurt: Integration of lycopene through dual-stage fermentation of soymilk.

Well-defined compositional assemblies of plant-based yogurt are of fast-growing awareness for world population concerning environmental sustainability, economic burdens and health risks. Soybean is an attractive candidate for plant yogurt, suffering from poor flavor, limited nutrition, and undesired allergens to offer healthy-functional segments. Herein, we deciphered a novel lycopene-soy yogurt by efficient two-stage fermentation of engineered B. subtilis and LAB. The fortified sogurt was ensured with redundant lycopene of 22.67 ± 2.95 mg/g DCW by engineered B. subtilis and enriched soy isoflavone from synergistic effects of engineered B. subtilis and LAB, possessing strong antioxidant capacity for upgrading functionality. Moreover, the desired pH, accelerated protein hydrolysis, enhanced amino acid availability, and expected sensory attributes cooperatively conferred lycopene-soy yogurt as healthy functional food. High potential is firstly ascribed to sequential dual culture of engineered B. subtilis and LAB in lycopene-soy yogurt, in which flavorful, hypoallergenic and antioxidative ingredients enabled functionalities for plant-based yogurt.

Metabolic Evaluation of Lupin-Enriched Yogurt by Nuclear Magnetic Resonance Metabolomics.

Untargeted nuclear magnetic resonance (NMR) metabolomics was used to evaluate compositional changes during yogurt fermentation upon lupin enrichment compared to traditional conditions. Lupin significantly changed the sample metabolic profile and its time course dynamics, seemingly delaying microbial action. The levels of organic and amino acids were significantly altered, along with those of some sugars, nucleotides, and choline compounds. Lupin seemed to favor acetate and formate synthesis, compared to that of citrate and fumarate; a higher formate levels may suggest increased levels of Streptococcus thermophilus action, compared toLactobacillus bulgaricus. Lupin-yogurt was poorer in hippurate, lactose (and hence lactate), galactose, glucose-1-phosphate, and galactose-1-phosphate, containing higher orotate levels (possibly related to increased uridine derivatives), among other differences. Trigonelline was confirmed as a lupin marker, possibly together with glutamate and histidine. Other metabolite trajectories remained unchanged upon lupin addition, unveiling unaffected underlying processes. These results demonstrate the usefulness of untargeted NMR metabolomics to understand/develop new foodstuffs and their production processes, highlighting the identity of a variety of bioactive metabolites with importance for human health.

Investigation of some quality properties of yogurt made from cow and sheep milk fortified with folic acid (B9 ), biotin (B7 ), and vitamin D3.

BACKGROUND: The aim of this study was to investigate the effects on some physicochemical properties and starter cultures of yogurts enriched with vitamins at different concentrations during storage. For this purpose, yogurt was produced by adding the vitamins folic acid (B9 ), biotin (B7 ), and vitamin D3 in different concentrations to sheep and cow milk and stored at 4 °C. Physicochemical analyses and microbiological analyses were performed for each group of yogurt on days 0, 7, 14, and 21. RESULTS: There was no significant difference (P > 0.05) between the groups in pH and titration acidity (%) during storage. It was determined that in the yogurts produced from sheep milk, the groups enriched with vitamins had a higher number of L. bulgaricus than the control group on the 7th day of storage. Moreover, the groups containing vitamin D3 exhibited a higher Lactobacillus bulgaricus count on the 21st day of storage. The highest L. bulgaricus counts on the 7th day in yogurts produced from cow's milk were observed in groups containing 0.5 mL of vitamin B9 and B7 . No mold or yeast growth was observed during storage in any of the yogurt groups made from cow and sheep milk. CONCLUSION: In conclusion, it was determined that the enrichment of yogurt with vitamins B7 , B9 , and D3 did not adversely affect the quality of the yogurt; rather, it improved. We recommend that yogurt enriched with micronutrients be studied economically, and mass production should be initiated by yogurt companies as soon as possible. © 2023 Society of Chemical Industry.

The effect of high-temperature heat treatment and homogenization on the microstructure of set yogurt curd networks.

Set yogurt's physical characteristics are greatly affected by the homogenization and heat treatment processes. In our previous study, set yogurt treated at 130°C and with the fat particle size reduced to ≤0.6 µm had equivalent curd strength, less syneresis and smoother texture than yogurt treated at 95°C. When investigating the mechanisms underlying yogurt's physical properties, it is important to evaluate the yogurt's microstructure. We conducted electron microscopy evaluations to investigate the mechanisms of changes in yogurt's physical properties caused by 130°C heat treatment and by a reduction in the fat globule size. We prepared yogurt mixtures by combining heat treatment at 95 and 130°C and homogenization pressure at 10 + 5 and 35 + 5 MPa and then fermented the mixtures in a common yogurt starter. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for the structural observations. Fine particles were observed on the surface of the casein micelles of the yogurt treated at 95°C, and the coalescence density between micelles was high. The surface of the yogurt treated at 130°C had few fine particles, and the coalescence density between micelles was low. The yogurt treated at 130°C with 35 + 5 MPa homogenization had low coalescence density between casein micelles, but smaller-particle-size fat globules increased the network density. Approximately 30% of the fat globules were estimated to be incorporated into the yogurt networks compared to the volume of casein micelles. We speculate that 130°C heat treatment alters the structure of whey protein on the surface of casein micelles and interferes with network formation, but reducing the size of fat globules reinforces the network as a pseudoprotein.

Characterization of Portulaca oleracea Whole Plant: Evaluating Antioxidant, Anticancer, Antibacterial, and Antiviral Activities and Application as Quality Enhancer in Yogurt.

Purslane (Portulaca oleracea L.) is rich in phenolic compounds, protein, and iron. This study aims to produce functional yogurt with enhanced antioxidant, anticancer, antiviral, and antimicrobial properties by including safe purslane extract in yogurt formulation; the yogurt was preserved for 30 days at 4 °C, and then biochemical fluctuations were monitored. The purslane extract (PuE) had high phenolic compounds and flavonoids of 250 and 56 mg/mL, respectively. Therefore, PuE had considerable antioxidant activity, which scavenged 93% of DPPH˙, inhibited the viability of MCF-7, HCT, and HeLa cell lines by 84, 82, and 80%, respectively, and inhibited 82% of the interaction between the binding between Spike and ACE2 compared to a SARS-CoV-2 inhibitor test kit. PuE (20-40 µg/mL) inhibited the growth of tested pathogenic bacteria and Candida strains, these strains isolated from spoild yogurt and identified at gene level by PCR. Caffeic acid glucoside and catechin were the main phenolic compounds in the HPLC profile, while the main flavor compound was carvone and limonene, representing 71% of total volatile compounds (VOCs). PuE was added to rats' diets at three levels (50, 150, and 250 µg/g) compared to butylated hydroxyanisole (BHA). The body weight of the rats fed the PuE diet (250 µg/g) increased 13% more than the control. Dietary PuE in rats' diets lowered the levels of low-density lipoprotein (LDL) levels by 72% and increased the levels of high-density lipoprotein (HDL) by 36%. Additionally, liver parameters in rats fed PuE (150 µg/g) decreased aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA) levels by 50, 43, and 25%, respectively, while TP, TA, and GSH were increased by 20, 50, and 40%, respectively, compared to BHA. Additionally, PuE acts as a kidney protector by lowering creatinine and urea. PuE was added to yogurt at three concentrations (50, 150, and 250 µg/g) and preserved for 30 days compared to the control. The yogurt's pH reduced during storage while acidity, TSS, and fat content increased. Adding PuE increased the yogurt's water-holding capacity, so syneresis decreased and viscosity increased, which was attributed to enhancing the texture properties (firmness, consistency, and adhesiveness). MDA decreased in PuE yogurt because of the antioxidant properties gained by PuE. Additionally, color parameters L and b were enhanced by PuE additions and sensorial traits, i.e., color, flavor, sugary taste, and texture were enhanced by purslane extract compared to the control yogurt. Concerning the microbial content in the yogurt, the lactic acid bacteria (LAB) count was maintained as a control. Adding PuE at concentrations of 50, 150, and 250 µg/g to the yogurt formulation can enhance the quality of yogurt.

Development of prebiotic yogurt with addition of green-banana biomass (Musa spp.).

This study evaluated the technological viability of yogurt with the addition of green-banana biomass (Musa spp.) considering the resistant starch (BBV) as a potential prebiotic ingredient and texture agent. Four yogurt formulations were prepared: control; 3% BBV; 5% BBV; and 10% BBV. They were subjected to analysis of resistant starch, lactose, fat, total dry extract, defatted dry extract, moisture, ash, proteins, pH and titratable acidity; syneresis analysis, instrumental texture and instrumental color. All four formulations met the requirements of the identity and quality regulation for fermented milks regarding the physicochemical and microbiological parameters. In the instrumental color analysis, in all treatments with added BBV, darkening was observed after 21 days, with a reduction of a* coordinate and an increase of b* coordinate. In the instrumental texture analysis, the yogurt in the Control treatment had the highest firmness (0.430 N) at 21 days among these treatments. Among the treatments with added BBV, the yogurt with 5% added BBV showed the best results for increasing the viability of lactic bacteria. It was found that yogurt with added BBV is a promising alternative in the elaboration of functional dairy products, adding value to the banana production chain by reducing the green fruit waste.

Physiochemical and Microbial Analysis of Tibetan Yak Milk Yogurt in Comparison to Locally Available Yogurt.

Yak yogurt, which is rich in microorganisms, is a naturally fermented dairy product prepared with ancient and modern techniques by Chinese herdsmen in the Qinghai-Tibet Plateau. The objective of this research was to assess the impact of Lactobacillus bulgaricus and Streptococcus thermophilus starter cultures on the quality and shelf life of yak yogurt, as well as the genetic stability across multiple generations, in comparison to commercially available plain yogurt and peach oat flavor yogurt. Following that, the samples were evenly divided into four treatment groups denoted as T1 (treatment 1), T2, T3, and T4, with each group employing a distinct source of yogurt formulation. T1 included L. bulgaricus, T2 comprised S. thermophilus, T3 consisted of plain yogurt, and T4 represented peach oat yogurt flavor. The findings indicate that T1 yogurt consistently presents a lower pH and higher acidity compared to the other three yogurt types throughout the entire generation process. Moreover, the fat content in all generations of the four yogurt types exceeds the national standard of 3.1 g/100 g, while the total solid content shows a tendency to stabilize across generations. The protein content varies significantly among each generation, with T1 and T4 yogurt indicating higher levels compared to the T2 and T3 yogurt groups. In terms of overall quality, T1 and T4 yogurt are superior to T2 and T3 yogurt, with T1 yogurt being the highest in quality among all groups. The findings revealed that the inclusion of L. bulgaricus led to enhanced flavor, texture, and genetic stability in yak yogurt. This study will serve as a valuable source of data, support, and methodology for the development and screening of compound starters to be utilized in milk fermentation in future research and applications.

Small molecule linoleic acid inhibiting whey syneresis via interact with milk proteins in the fermentation of set yogurt fortified with c9,t11-conjugated linoleic acid.

The study aimed to investigate the impact of fermentation conditions on c9,t11-conjugated linoleic acid (CLA) synthesis by Lactobacillus casei, as well as its effects on whey syneresis, water holding capacity (WHC), and texture characteristics of set yogurt. The amount of whey syneresis decreased about 30% with the adding of 0.1% linoleic acid (LA). The interaction between LA and casein (CS), ß-lactoglobulin (ß-Lg) and bovine serum albumin (BSA) was observed by UV-Vis absorption spectroscopy, 3D fluorescence spectroscopy and CD spectroscopy. It found that LA changed the microenvironment and polarity around amino acids, as well as the conformation of the three milk proteins. Scanning electron microscope (SEM) analysis revealed that the addition of LA resulted in a more uniform and compact microstructure of the set yogurt. It indicates that LA can promote the crosslink of milk proteins, which may be the reason for the reduction of whey syneresis in set yogurt.