Conventional Yogurt Research Articles

Quince Powder Increases Antioxidant Activity and Probiotic Survival in Yoghurt.

In recent years, there has been a growing interest in incorporating fruit-based additives into yogurt formulations as a means to improve the functionality of the product. This study aims to produce a functional product by incorporating quince, which is rich in fibre, vitamins, minerals and antioxidant activity, into a yoghurt formulation. The influence of the addition of quince powder (0 (control), 0.5, 1.0 and 1.5 %) on the antioxidant and proteolytic activities and culture viability of probiotic yoghurt was investigated for 28 days. The viable counts of yoghurt bacteria and Bifidobacterium lactis BB-12® were above 8 log CFU/g. Higher viability of all bacteria was obtained in yoghurt fortified with 1.5 % quince powder than those of other samples after 14 days. Probiotic yoghurt with added 1.5 % quince powder had the highest proteolytic activity during the last two weeks of storage, while the highest total phenolic content and (2,2-diphenyl-1-picrylhydrazyl) radical (DPPH˙) scavenging activity were obtained for the same sample throughout the storage period. Quince powder supports the health of the digestive system thanks to its high fibre content, while it is also rich in vitamins, minerals and antioxidant activity. These properties emphasise the importance of using quince powder in yoghurt production. This innovation has the potential to provide consumers with a tasty alternative, while at the same time increasing the intake of health-promoting ingredients. Furthermore, such products offer higher nutritional value than conventional yoghurt, offering consumers with a healthier option. Therefore, the production of yoghurt with quince powder can be considered as an important innovation in the field of nutrition and a practice that contributes to increasing health awareness.

Enhancing probiotic survival and quality of fermented goat milk beverages with bael (Aegle marmelos) fruit pulp

This study aimed to assess the impact of bael fruit pulp on the viability of probiotic Lacticaseibacillus rhamnosus GG (LGG) and some physicochemical properties of bael-goat milk-based beverages during 21 days of refrigerated storage. Bael fruit pulp (BFP) was incorporated into goat milk (GM) at different levels (0 %, 5 %, 10 %, and 20 %), and fermented with LGG combined with conventional yoghurt culture. Products were analyzed at weekly intervals. Fermented GM without bael served as control. Redness (a*), yellowness (b*), chroma, and LGG viability were all significantly increased while pH, lightness (L*), and whiteness were dramatically decreased by the addition of BFP. After 14 days of storage, all fermented milk containing bael exhibited considerably (p < 0.05) greater LGG counts than the control. The product containing 20 % bael had the greatest viability counts (7.01 log CFU/mL) at the end of storage. Throughout the storage period, all of the products—including the control—maintained viable probiotic counts of greater than 6 log CFU/mL. The pH of the products decreased over time but was stabilized by bael. In conclusion, the findings demonstrate that goat milk is a perfect vehicle for LGG, and adding bael may boost the fermented goat milk's probiotic viability, physicochemical qualities, and nutritional value, thus improving its overall quality.

Low-intensity pulsed electric fields pre-treatment on yogurt starter culture: Effects on fermentation time and quality attributes

Low-intensity pulsed electric fields (PEF) were applied to a starter culture mix (Streptococcus thermophilus, Lactobacillus bulgaricus, and partially skimmed milk) before the fermentation stage of natural yogurt. The impact of PEF processing conditions on yogurt fermentation time and quality characteristics was evaluated. PEF parameters were set based on a factorial experimental design; independent variables: electric field strength, pulse-frequency, and pulse-width, were explored, having fermentation time as a response. Most PEF treatments reduced fermentation time by 0.31–0.52 h compared to conventional yogurt processing (CY) (4.70 ± 0.23 h). The shortest time (4.18 ± 0.04 h) resulted from PEF pre-treatment with 8-μs monopolar pulses at 1 kV/cm and 150 Hz during 400 μs. The physicochemical and sensory characteristics of PEF-treated yogurt were similar to those of the CY immediately after processing and during refrigeration storage. Low-intensity PEF could be a promising alternative pre-treatment of yogurt production, reducing fermentation time while maintaining quality attributes of natural yogurt. Industrial relevanceConventional yogurt processing lasts around 4.5–6 h, representing high energy consumption and production costs. The application of pulsed electric fields (PEF) processing to the starter culture before yogurt fermentation represents a potential alternative to diminish production time by stimulating lactic acid bacteria and accelerating fermentation stage. This study demonstrated that low-intensity PEF (1–3 kV/ cm) reduced fermentation time by 0.31–0.52 h without compromising yogurt's quality properties, including physicochemical characteristics and sensory attributes. Obtained results suggest that this technology allows more efficient and sustainable yogurt production methods, positively impacting industry and consumers.

Effect of combination of Beta Glucan and Lactobacillus rhamnosus HerizI on white blood cell counts and serum levels of IL-4 and IL-12 in women with breast cancer undergoing chemotherapy: A randomized double-blind placebo-controlled clinical trial

BackgroundAim of this study was the isolation of native probiotic and determine the effect of combination of Beta Glucan and Lactobacillus rhamnosus Heriz I on White Blood Cell Counts and serum levels of IL-4and IL-12 in breast cancer women receiving Chemotherapy. MethodsThis study was randomized double-blind placebo-controlled clinical trial in 30 women with breast cancer. Women in the intervention group received two 10-mg capsules of soluble 1–3,1–6, D-beta glucan and one capsule of Lactobacillus rhamnosus strain Heriz I (2×107 CFU) daily and placebo group received placebo during 21days, interval between two courses of chemotherapy. White blood cells, neuthrophil, lymphocyte and monocyte counts, serum levels of IL-4 and IL-12 were measured before and after the study. ResultsWe isolated Lactobacillus rhamnosus Heriz I from conventional yogurt of Heriz region and registered in NCBI GeneBank. After administration, in both groups white blood cells counts decreased. At the end of study, serum level of IL-4 was decreased in combination group compared to placebo (P=0.005). Also, serum level of IL-12 in combination group increased non-significantly (P=0.066). ConclusionThe findings suggest that combination of Beta Glucan and Lactobacillus rhamnosus Heriz I may be useful as immunomodulary supplements in chemotherapy patients however further studies were needed.

MICROPLASTIC DEBRIS IN YOGURT: OCCURRENCE, CHARACTERIZATION, AND IMPLICATIONS FOR HUMAN HEALTH

The present study aimed to identify and characterize the microplastics (MPs) extracted from conventional and organic yogurt, sold in large hypermarket chains in Romania. In this respect, the morphology and chemical composition of MPs, as well as the health risks generated by their presence in yogurt were important to investigate. In the yogurt samples were identified by optical microscopy a reasonably high number of microparticles (black, blue, red, gray, etc.): ~2236 / kg in conventional yogurt and ~2266 / kg in organic yogurt. The micro-FTIR analysis along with OPUS v.7.5 software’s library revealed their composition. The complexity of the study was not generated only by the analytical methods used to characterize the MPs but also by the isolation process required for this. Therefore, the results revealed the presence of microparticles of cotton, cellulose, wool, raffia, and flax, (considered natural microparticles), but also mixtures with polymers (acrylic, nylon, polyester, cellophane, polyurethane, polyethylene, etc.), considered synthetic microparticles. Based on the above results could be established the correlations and the statistical approach, information that may serve or act as an incentive for milk and dairy product processors to try to find the source of contamination, starting with the raw material, continuing with the processing chain, and ending with the final product.

Utilisation of Lacticaseibacillus casei ATCC 393‐derived exopolysaccharide for camel milk yoghurt production and its potential anticancer and hepatoprotective properties

Camel milk yoghurts were created using probiotic lactic acid bacteria (LAB) with exopolysaccharide (EPS) production capabilities. Lacticaseibacillus casei ATCC 393, identified as the most efficient EPS producer, was incorporated into conventional yoghurt culture. We compared the effects of adding L. casei ATCC 393 with EPS powder (SLLP) against lactulose. Evaluations included LAB, yeast, mould, cytotoxicity and IC50 values in the samples. The results demonstrated increased bacterial counts, LAB viability, viscosity, antiproliferative effects and a lower IC50 in SLLP, indicating the potential application of EPS‐producing L. casei ATCC 393 and its derived EPS in the development of functional foods.

Appraisal of Proximate Composition in Tiger Nut Yogurts and Selected Commercially Available Yogurts in Enugu, Enugu State, Nigeria: A Comparative Study

This study evaluated the physicochemical, chemical and microbial compositions of tiger nut and selected conventional yoghurts. During the study proximate, mineral, vitamins, chemical and physicochemical and bacterial analysis were done accordingly. The results of proximate analysisshow that the fat and crude fibre compositions of tiger nut differed significantly (p &lt; 0.05) with the values of conventional yoghurts, while no significant difference (p &gt; 0.05) was observed in the concentration values of ash. Tiger nut yoghurts recorded highest values of 8.39±0.04 mg/l (vitamin C), while Cd, Ni and Pb were below detectable limit in all the yoghurts. The concentration values of Cu in the conventional and tiger nut yoghurts varied significantly (p &lt; 0.5). Tiger nut yoghurt concentration values of polyphenol, total tannin and phytate are significantly different (p &lt; 0.05). Results show that pH, TTA and conductivity values in sample A, B and tiger nut yoghurts are not significantly different (p &gt; 0.05), while it differed significantly (p &lt; 0.05) with reference to viscosity, TSS, TS and magnesium. The microbial cell count of Lactobacillus acidophilus was dependent on innoculum size and number of days. At day 7 conventional yoghurt A, tiger nut yoghurt and conventional yoghurt B recorded the highest loads of TVC (3.8 x 102), TCC (4.33 x 102) and TBC (6.12 x 107), while the highest loads of 3.3 x 105 (TVC), 5.1 x 103 (TCC) and 4.1 x 106 (TBC) are observed in the tiger nut yoghurt, yoghurts A and B at day 14 respectively. The study recommends production and promotion of plant basedyoghurts drink for improvement of healthy and unhealthy individuals.

Development of dairy‐free soybean‐based yoghurt by active dry starter culture from kombucha: an investigation into microencapsulation, curd formation, protein and texture profiles during storage

SummaryIncreasing demand for the production and use of non‐dairy products has resulted from the rapid increase of vegetarian and lactose‐intolerant populations. In this study, non‐dairy yoghurt was developed from soybeans using microencapsulated starter culture consisting of Levilactobacillus brevis and Saccharomyces cerevisiae isolated from kombucha based on spray drying and freeze drying techniques using 20% maltodextrin (MD) and gum Arabic‐maltodextrin mixture (GA‐MD) as carriers. Scanning electron microscopy revealed high integrity and effective microbial protection within the carrier matrices, especially for freeze‐dried samples with L. brevis density being in the range of 6.1–6.4 log CFU/g. During 21‐day storage of microcapsules at 4 °C, L. brevis density decreased to 4.4–5.1 log CFU/g for all carriers while GA‐MD was incapable of preserving its viability at 30 °C. Meanwhile, the soybean‐based yoghurt was produced using these four microcapsules as active dry starter culture for the investigation of warm incubation/curd formation and subsequent refrigeration. Regarding warm incubation, in contrast to conventional yoghurt, there was no drop in pH or total acidity over the first 7–8 h of storage, followed by their sudden decline which led to the curd formation in the next hour at pH and total acidity of 5.42–5.75 and 2.29–3.06 g lactic acid/L respectively. Furthermore, GA‐MD samples exhibited more severe syneresis and surface cracks than MD during refrigeration in which the hardness and gumminess of yoghurt increased over time. Electrophoresis results also confirmed the proteolytic activity of lactic acid bacteria and yeast on β‐conglycinin and glycinin fractions of soy proteins.

Development of a functional Greek sheep yogurt incorporating a probiotic Lacticaseibacillus rhamnosus wild-type strain as adjunct starter culture

Greek yogurt is a fermented dairy product of high nutritional value that can be used as a matrix for the delivery of probiotics. The aim of this study was to develop a new probiotic Greek sheep yogurt with upgraded quality and functional characteristics. To do this, yogurt was manufactured by fermenting pasteurized milk with the commercial starter culture (Streptococcus thermophilus (ST), Lactobacillus bulgaricus (LB)) together with a probiotic Lacticaseibacillus rhamnosus (LR) wild-type strain (probiotic yogurt; PY). As a control, yogurt manufactured with only the starter culture (ST, LB) was used (conventional yogurt; CY) The survival of all three lactic acid bacteria (LAB) species (ST, LB, and LR) was monitored throughout the products’ shelf life (storage at 4 °C for 25 days), and also following exposure to a static in vitro digestion model (SIVDM). The population dynamics of total aerobic plate count (APC), Enterobacteriaceae, yeasts and molds grown in both yogurts were also determined. The total antioxidant activity (AA) of yogurts was comparatively determined using in parallel two different assays, whereas the Folin-Ciocalteu assay was used to determine their total phenolic content (TPC). At each sampling day, yogurts were also evaluated for their pH, titratable acidity (TA) and main sensory characteristics. The population of probiotic LR remained stable during the shelf life (and above 108 CFU/g). Yogurt starters (ST, LB) were not detected following SIVDM, whereas LR (in PY) presented a reduction of about only one log. The AA and TPC of PY were found significantly higher than that of CY (P < 0.05). At the end of storage (25th day), neither pH nor TA differed significantly between the two yogurt types, while no fungal growth was observed in the PY. Consumer sensory analysis did not reveal important differences between the two yogurt types during their shelf life. To sum up, the novel yogurt was able to deliver to consumers a high number of probiotic cells (>108 CFU/g), presented increased antioxidant power, had an expanded shelf life, and maintained its good sensory attributes.

Bio-hydrolysis Study of Lactose in Produced Yoghurt by β-Galactosidase from Lactobacillus fermentum

The present study investigated the physicochemical and biohydrolysis of lactose in conventional and locally produced yoghurt drinks, respectively. Physicochemical properties of the conventional yoghurt in the presence of the locally produced one were: pH 3.0; 4.0, titratable acid 1.14; 1.04, conductivity 2751.54, 2204, viscosity 71.11; 112.14, TDS 1788.5; 1433, TSS 781; 654, TS 3532.54; 2087, Mg 11.06; 34.19, Ca 28.76; 45.21, TOC 155.23; 145.23 and TOM 190.93, 178.63 for yoghurt sample I and II respectively. Lactose concentrations of the respective yoghurts were: 2.12 and 1.79 Mg/ml. β-galactosidase was produced from isolated Lactobacillus sp under submerged fermentation system after 12 days of incubation. 60% ammonium sulphate was found suitable for precipitation of proteins with highest enzyme activity, the precipitate was desalted through reverse osmosis using dialysis bag. Optimum biohydrolysis was achieved after 20 hours of incubation with residual sugar concentration of 0.51 mg/ml while the control experiment had 0.93 mg/ml of the residual sugar. Optimum pH and temperature of hydrolysis were: 5.0 and 70°C respectively. Rate of hydrolysis proceed linearly as the enzyme concentration increases from 0-20% v/v. the present study has shown exclusively the nutritional components of yoghurts drinks commercially sold in the market, it went further to show hope for the metabolic compromised individuals with intolerance to lactose as the enzyme lactase produced from non noscomial organism showed great potentials of hydrolysis.

Physicochemical profile, amino acid, and flavors of probiotic yogurt with the addition of nano ZnO food grade

Yogurt is a functional food produced through milk fermentation by yogurt bacteria. The addition of Lactiplantibacillus plantarum IIA-1A5 in the fermentation of yogurt yielding a yogurt probiotic has been shown to exhibit some functional properties. The effects of adding ZnO on the overall properties of the yogurt are unknown. This study aimed to investigate the effect of ZnO nanoparticles on the characteristics of conventional yogurt and yogurt probiotics. Four sets of yogurts were prepared: conventional yogurt, yogurt with added ZnO, yogurt probiotic, and yogurt probiotic with added ZnO. Most of the physicochemical properties of all yogurts were found to be comparable, except for fat and solid non-fat contents. The addition of ZnO increased the total lactic acid bacteria (LAB) in the yogurt, but it apparently inhibited L. plantarum IIA-1A5 as indicated by a lower LAB population in the yogurt probiotic with added ZnO compared with the yogurt probiotic without ZnO. However, the combination of L. plantarum IIA-1A5 and ZnO in yogurt significantly enhanced the DPPH inhibition activity. Additionally, the positive effects of ZnO were also observed on the total amino acid content, which significantly modulate the flavor compounds. This indicates that, overall, ZnO contributed to the better characteristics of yogurts.

Effect of probiotic yogurt consumption on glycemic control and lipid profile in patients with type 2 diabetes mellitus: A randomized controlled trial

Type 2 diabetes mellitus (T2DM) is a common endocrine disease. Altered gut microbiota (Dysbiosis) is closely associated with development of T2DM. Growing body of evidence hypothesized that probiotics intake may be useful for patients with T2DM. We investigated the effect of probiotic yogurt consumption on glycemic control and lipid profile in patients with T2DM. In this 12-week randomized controlled clinical trial, seventy-two patients with T2DM were randomly assigned to the intervention group (IG) that received 200g/d probiotic yogurt containing 4.65×106CFU/g Lactobacillus acidophilus and Bifidobacterium lactis) or placebo group (PG) that received 200g/d conventional yogurt. We found no difference between two groups in fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-c) and low density lipoprotein-cholesterol (LDL-c) after intervention. After adjusting for baseline values of covariate, a significant reduction in HbA1c (mean change:-0.76±1.3 vs.-0.15±1.3; P=0.01), TC (mean change:-10.61±27.8 vs.-2.97±35.0; P=0.02) and LDL-c (mean change:-8.62±21.7 vs. 0.02±25.8; P=0.004) was observed in the IG compared to the PG. In addition, a non-significant trend to reduction was observed in term of FPG (mean change:-19.61±29.1 vs.-4.19±24.2; P=0.13). TG and HDL-c remained unchanged. Probiotic yogurt consumption may be useful for patients with T2DM. More well-designed clinical trials with longer intervention duration are required. Registered on 30 July 2022at Iranian Registry of Clinical Trials (IRCT20220226054125N1) with URL: https://www.irct.ir/trial/62304.

Studies on Addition of Four o'Clock Flowers (Mirabilis jalapa) Extract on Physiochemical, Microbiological and Sensory Analysis Properties of Yoghurt

Background: Milk and other dairy products are the most stable which contains of minerals, vitamins and carbohydratese for all social groups and all age people. The additives of plants are multifunctional use in the dairy industry. Wild plants have the good property of vitamins, minerals, and some other biologically active substances. Because of these compounds, digestion has been improved. Materials and Methods: This study was done in the food technology and nutrition department, School of Agriculture, Lovely Professional University, Phagwara, Punjab. Mirabilis Jalapa flowers have been gotten from Phagwara model town. The flowers collected at the evening, then were dried at the oven, and the second procedure is making powder of the flowers. Milk was collected from the local market then heat it and pasteurized for 5 minutes at 95 centigrade, cooling at 45 centigrade. Findings: We observed that Mirabilis Jalapa flower extracts were not commonly integrated into the raw milk components. Various extract concentrations, ranging 0%, 2%, 4%, 6%, 8%, and 10%, respectivly, were incorporated into raw milk, with a 5% lactobacillus culture, omitting the use of a control sample. After 24-hour fermentation period, the acidity levels of the samples ranged from 1.05% for the control to 1.45% for the 10% fortified yogurt. Over time, the pH values of the different extract concentrations exhibited a gradual decline. Moreover, with various concentrations of Mirabilis Jalapa extracts exhibited extended shelf lives, with durations of 24 days, 28 days, 32 days, and 34 days for extract concentrations of 2%, 4%, 6%, 8%, and 10%, respectively. Conclusion: The experimental findings show that the fortified yogurt with Mirabilis Jalapa’s extract shelf life extended, adding more extracts means extending shelf life, whereas conventional yogurt exhibited a comparatively shorter shelf life of 23 days.

Probiotic Limosilactobacillus fermentum GR-3 ameliorates human hyperuricemia via degrading and promoting excretion of uric acid

SummaryProbiotics have demonstrated the potential to ameliorate hyperuricemia in animals, but their effectiveness and mechanism of action in humans has been understudied. A randomized, double-blinded, controlled research was conducted with 120 volunteers, who consume either a probiotic yogurt containing a UA-degrading strain Limosilactobacillus fermentum GR-3 or a conventional yogurt for 2 months, to investigate probiotic yogurt helped decrease uric acid levels in the at-risk human population. Serum UA levels showed that the probiotic yogurt caused a significant decrease than the consumption of conventional yogurt (26.2% ± 2.3% vs. 8.6% ± 1.1%), and contributed to the UA excretion in the feces and urine (7.4% ± 2.1% and 13.8% ± 3.4%, respectively, 1.9% ± 1.1% and 5.1% ± 2.2%, respectively). Metabolomics and microbial community analysis showed a positive correlation with enhanced anti-inflammation of the host. Our findings suggest an effective and economical therapeutic adjuvant in treating hyperuricemia.

Human supplementation with Pediococcus acidilactici GR-1 decreases heavy metals levels through modifying the gut microbiota and metabolome

Exposure to heavy metals (HMs) is a threat to human health. Although probiotics can detoxify HMs in animals, their effectiveness and mechanism of action in humans have not been studied well. Therefore, we conducted this randomized, double-blind, controlled trial on 152 occupational workers from the metal industry, an at-risk human population, to explore the effectiveness of probiotic yogurt in reducing HM levels. Participants were randomly assigned to two groups: one consumed probiotic yogurt containing the HM-resistant strain Pediococcus acidilactici GR-1 and the other consumed conventional yogurt for 12 weeks. Analysis of metal contents in the blood revealed that the consumption of probiotic yogurt resulted in a higher and faster decrease in copper (34.45%) and nickel (38.34%) levels in the blood than the consumption of conventional yogurt (16.41% and 27.57%, respectively). Metagenomic and metabolomic studies identified a close correlation between gut microbiota (GM) and host metabolism. Significantly enriched members of Blautia and Bifidobacterium correlated positively with the antioxidant capacities of GM and host. Further murine experiments confirmed the essential role of GM and protective effect of GR-1 on the antioxidative role of the intestine against copper. Thus, the use of probiotic yogurt may be an effective and affordable approach for combating toxic metal exposure through the protection of indigenous GM in humans.ClinicalTrials.gov identifier: ChiCTR2100053222

Effect of whey and soy proteins fortification on the textural and rheological properties of value-added yogurts

The objective of this study was to develop whey and soy proteins fortified value-added yogurts based on their textural and rheological properties to meet a high demand to increase protein content of conventional yogurts for many health benefits. Seven yogurts (control, 1, 3 and 5% of whey/soy proteins) were developed by fortifying with whey and soy proteins. The protein fortified yogurts were compared with control (without protein fortification) for their textural and rheological properties. The dynamic viscosity of yogurts was determined, and the shear stress-shear rate relationship was modeled using a power law equation to determine the apparent viscosity and flow behavior of yogurts. There was a significant effect of protein fortification on the textural and rheological properties of yogurts (p < 0.05). The textural properties and viscosities of 1-5% soy protein fortified samples were close or better to control. Textural and rheological properties of the yogurts indicated that up to 5% soy protein could be incorporated for the quality yogurts. whereas only 1-3% whey fortification of yogurt was possible because 5% whey protein created aggregates and syneresis of yogurts. Power law modeling could predict the shear stress and shear rate relationship and apparent viscosity of all yogurts with an accuracy of 80-99% depending on level of protein fortification and protein type. Dynamic viscosity and apparent viscosity of all yogurts decreased with shear rate. Power law (n < 1) showed that all yogurt samples were shear thinning products. The desired viscosity could be obtained using an optimum protein fortification. The study indicated that soy protein could be used as an alternative to whey protein for the improved protein fortified yogurt production.

The impact of combination of solution plasma processing and pulsed electric field on the viability of probiotic bacteria, microbial growth, and structure of yoghurt drink

In this study, the properties of the milk treated with combination of solution plasma (SP) processing and pulsed electric field (PEF) for different periods (5 and 10 min) was investigated. The microbiological, physicochemical, and sensory properties of the probiotic yoghurt drink (Ayran) produced from these milks were determined during storage. PEF was performed at voltage 3500 V, repetition 17,000 Hz, and pulse width 2.58 μs on the raw milk. Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis probiotic cultures were used in production with conventional yoghurt bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. In addition to the probiotic viability, texture and sensory quality in terms of consumer preference were investigated. It was determined that the viscosity and dry matter values of the solution plasma-treated samples were lower compared to the samples produced by heat treatment, and these values decreased further with the increase in plasma application time. It was also found that the maximum increase in L* and b* values of all samples during storage was in the samples treated with plasma for 10 min. The viability of the probiotic bacteria in probiotic Ayran samples were determined to be within the therapeutic level (>6.27 log10 cfu ml−1) with higher scores for sensorial qualifications. Practical applications Consumers’ expectations of more nutritious and microbiologically safe food have enabled the development of new processing technologies. Probiotic fermented milk products are products that provide health benefits in the prevention of gastrointestinal diseases, regulation of metabolism, and stimulation of the immune system. The processing of these dairy products with non-thermal technologies provides advantages in preserving their functional properties.

Sensory and microbiological evaluation of probiotic yoghurt made with different types of probiotic cultures starter Lactobacillus acidophilus LA-5 ® and Bifidobacterium animalis subsp. lactis BB-12®

The incorporation of probiotic bacteria into yoghurt is believed could increase its health benefits such as improving intestinal health, reducing the risk of type 2 diabetes mellitus and more. The objective of this study was to evaluate the sensory and microbiological characteristics of probiotic yoghurt (PY) made with 2 types of starter cultures namely direct vat set (DVS) cultures and heirloom (HC) cultures. Lactobacillus acidophilus LA5 ® and Bifidobacterium animalis subsp. lactis (BB-12® ) used in this study were obtained from Chr. Hansen. Conventional yoghurt (CY) was made with Lactobacillus delbrueckii subsp. bulgaricus (Lb) and Streptococcus thermophilus (St). As much as 2% of starter cultures were added into 10% skimmed milk suspension with 10% of sucrose. Lb:St ratio in CY was 1:1, whereas Lb:St:LA-5:BB-12 ratio in PY was 1:1:2:2. The mixture was incubated at 38°C for 6-8 hrs. Total lactic acid bacteria and bifidobacteria, as well as pH value, were determined at 0, 1st, 2nd, 3rd, 4th week of storage. The sensory properties of yoghurt were evaluated at the 0th week and the 4th week. The results showed that after 4 weeks of storage at 4°C, the total lactic acid bacteria were slightly decreased ranging from 0.26 log CFU/mL (DVS-PY) to 0.79 log CFU/mL (CY), while total bifidobacteria was slightly decreased from 0.40 to 0.58 log CFU/mL. The pH value of CY was significantly decreased after 4 weeks of storage, while the pH values of DVS-PY and HC-PY were not significantly different. The result from the Triangle test revealed that DVS-PY has similar sensory properties with CY whereas HC-PY has less thickness. In general, the sensory properties of CY and PY were slightly decreased after 4 weeks of storage at 4°C. In conclusion, incorporation of probiotic bacteria in yoghurt with DVS starter culture give better microbiological and sensory properties compared to HC starter culture.

Effects of 12-week, non-energy-restricted dietary intervention with conventional yogurt οn appetite hormone responses of type 2 diabetic patients.

Hunger‐reducing effects and beneficial changes in gastrointestinal hormones have been reported, in overweight/obese individuals consuming dairy while yogurt takes pride of place due to its unique structure and composition. Although the contribution of yogurt to metabolic regulation has received growing attention, the research studies which examine its role on appetite are limited, especially regarding type 2 diabetes mellitus (T2DM) patients. The aim of the present study was to investigate the effects of non‐fat, conventional yogurt consumption on appetite hormone responses of T2DM patients following a non‐energy‐restricted diet. Overweight subjects participated in a 12‐week dietary intervention including 2 meals/day (2 × 200 g) of yogurt. At the beginning and the end of the intervention, a mixed meal tolerance test assessing the postprandial response of glucose, insulin, ghrelin, glucagon‐like peptide‐1 (GLP‐1), and peptide‐YY (PYY) was performed. Subjective appetite ratings were also evaluated. Area under the curve for glucose, insulin, ghrelin, GLP‐1, and PYY responses did not differ after the 12‐week intervention with yogurt (p > .05) as well as for subjective appetite ratings (p > .05). No significant differences were indicated at specific time points in any of the examined parameters. Regular consumption of non‐fat, conventional yogurt for 12‐week duration does not affect appetite hormone responses in overweight patients with T2DM following a non‐energy‐restricted diet.

Use of encapsulated Bifidobacterium animalis subsp. lactis through extrusion or emulsification for the production of probiotic yogurt

AbstractIn this study, the methods of extrusion and emulsification were applied for the encapsulation of Bifidobacterium animalis subsp. Lactis before its incorporation into yogurt products, aiming to increase its viability during storage. Alginate based encapsulating blends containing 2% w/v sodium alginate and 11% v/v glycerol (AG) or 1% carrageenan (AC), and/or 2% w/v inulin, were applied for the encapsulation of probiotic bacteria. The produced beads were examined in order to determine the encapsulation yield and were also tested on milk fermentation along with conventional starter culture for yogurt production. The evolution of the fermentation was recorded through pH monitoring and the final products were evaluated regarding their rheological and texture characteristics, as well as their probiotic bacterial load during storage. It was concluded that the emulsification method led to higher encapsulation yield (95.4–97.6%) compared to the extrusion method (76.6–85.8%). The probiotic culture contributed to milk fermentation into yogurt, as it required less time to complete fermentation compared to samples containing only conventional culture. The encapsulation of probiotic bacteria was proved efficient in protecting their viability even after 30 days of storage (up to 6.9 log cfu/g). Thus, the incorporation of encapsulated probiotic bacteria improved in total the yogurt products and ensured the viability of probiotic bacteria till the end of storage.Practical ApplicationsThe encapsulation of probiotic bacteria is an innovative approach for their protection and the ensuring of their viability during food processing and storage, as well as during consumption. The methods of extrusion and emulsification are feasible and affordable in industrial scale. The current study provides an integrated approach of their application in yogurt production, without restricting the utilization of the produced encapsulated bacteria for the development of other probiotic products. The incorporation of encapsulated probiotic bacteria along with the conventional culture led to shorter fermentation times, and superior final products in comparison to conventional yogurt products. The final products had improved rheological and texture characteristics, whereas the viability of the probiotic bacteria remained at satisfactory levels till the end of storage.