Yogurt Processing Research Articles

Phenotypic Differentiation of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus Isolates Found in Yogurt Starter Cultures

The mutualistic relationship between Streptococcus thermophilus (S. thermophilus) and L. delbrueckii subsp. bulgaricus (L. bulgaricus) is responsible for milk coagulation, gel formation, and the flavour of yogurt. Under set-style yogurt processing conditions, the performance of a mixed culture composed of these species depends on key technological parameters such as the capacity for acidification and proteolytic activity. This study aimed to determine the extent of phenotypic diversity by comparing the key traits of acidification and proteolytic activity among isolates found in yogurt starter cultures. Seventy-two isolates from three industrial starter cultures were ranked by either their fast or slow acidification activity (time to reach pH 4.6, 16 h), proteolytic activity, cell envelope proteinase (CEP) activity, redox potential and titratable acidity. The integration of multiple phenotype measures by hierarchical clustering and non-metric dimensional scaling (NMDS) clustered groups of isolates by multifactor similarity. A significant difference (p-value < 0.05) was observed between the clusters regarding redox potential and the proteolytic activity of both S. thermophilus and L. bulgaricus. The integration of multiple phenotypes points to the diversification that may have occurred over repeated culturing of yogurt starter bacteria. The phenotypic diversity may explain the divergence in starter performance and be used to refine the formulation of new starter cultures. Future work will investigate the correlation between the activity of specific enzymes based on the phenotype to explain the separation between the fast and slow acidification of isolates.

Physicochemical properties of yoghurt with the addition of mint leaf powder (Mentha piperita)

Abstract Yoghurt is one of the functional foods that are popular in society that can be made from milk. The use of mint leaves, a natural element that provides benefits without negatively impacting the processing method or the end product, has been a recent advance in yoghurt processing. The physical and chemical characteristics of yoghurt mixed with powdered mint leaf are the focus of this study. This research employed a Completely Randomized Design (CRD) with three treatments: 1) no addition of mint leaf powder; 2) addition of mint leaves at 4.54%; and 3) addition of 9.08% mint leaf powder. Physicochemical tests are pH, viscosity, TAT, and antioxidants. The findings demonstrated that while the addition of mint leaves had no discernible impact on pH, TTA, or viscosity, it had a highly significant (p<0.01) influence on the antioxidant content of yoghurt. Therefore, we can conclude that adding mint leaves enhances the antioxidant value and also increases the quantity of mint leaves added.

Enhancement of the energy and exergy analysis capabilities of the yoghurt process: a case study of the dairy industry

This study provides a comprehensive analysis of the thermal and exergy characteristics of a dairy plant that produces yoghurt. This study aims to perform a comprehensive analysis of the thermal and exergy aspects of a dairy facility that produces yoghurt. This study also seeks to improve the accuracy of the results by evaluating the reliability of the energy and production data. A comprehensive analysis of energy and exergy is utilized to enhance the yoghurt production process. Moreover, the Grassmann-Sankey diagram is employed to produce a map of energy density. The process’s energy and exergy efficiencies were assessed by taking into account the enhancements and alterations made in addition to the existing implementations. Analysis of the yoghurt production process revealed that the total energy input was 113.9 [kW], the total energy output was 72.05 kW as well and the energy efficiency was 63.3%. The exergy input and output for the yoghurt production process were calculated to be 48.95 [kW] and 29.77 [kW], and the exergy efficiency was determined to be 60.8%. This study is expected to promote the growth of livestock and agriculture in the energy sector, and is forecasted to act as a catalyst for future research. This study, which is the first of its kind in the region and is expected to stimulate further research, reveals that improving energy efficiency and conservation in the production of yoghurt products enhances the factory’s overall energy efficiency.

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.

Natural approach of using nisin and its nanoform as food bio-preservatives against methicillin resistant Staphylococcus aureus and E.coli O157:H7 in yoghurt

BackgroundNatural antimicrobial agents such as nisin were used to control the growth of foodborne pathogens in dairy products. The current study aimed to examine the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against methicillin resistant Staphylococcus aureus (MRSA) and E.coli O157:H7 during the manufacturing and storage of yoghurt. Nisin NPs were prepared using new, natural, and safe nano-precipitation method by acetic acid. The prepared NPs were characterized using zeta-sizer and transmission electron microscopy (TEM). In addition, the cytotoxicity of nisin NPs on vero cells was assessed using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined using agar well-diffusion method. Further, fresh buffalo’s milk was inoculated with MRSA or E.coli O157:H7 (1 × 106 CFU/ml) with the addition of either nisin or nisin NPs, and then the inoculated milk was used for yoghurt making. The organoleptic properties, pH and bacterial load of the obtained yoghurt were evaluated during storage in comparison to control group.ResultsThe obtained results showed a strong antibacterial activity of nisin NPs (0.125 mg/mL) against MRSA and E.coli O157:H7 in comparison with control and pure nisin groups. Notably, complete eradication of MRSA and E.coli O157:H7 was observed in yoghurt formulated with nisin NPs after 24 h and 5th day of storage, respectively. The shelf life of yoghurt inoculated with nisin nanoparticles was extended than those manufactured without addition of such nanoparticles.ConclusionsOverall, the present study indicated that the addition of nisin NPs during processing of yoghurt could be a useful tool for food preservation against MRSA and E.coli O157:H7 in dairy industry.

The optimisation of processing and storage conditions of lyophilised purslane‐fortified yoghurts by central composite design

The objectives of this study were to manufacture lyophilised purslane‐fortified yoghurts in order to improve the functional properties of yoghurt and to optimise processing and storage conditions of fortified yoghurts. A central composite design was created by considering the storage time (5–12 days), lyophilised purslane concentration (0.25–0.5%) and starter culture ratio (1–3%) as factors. The fortified yoghurts were supplemented by phenolics (up to 36.94 mg gallic acid equivalent per kg) and linoleic acid (3.15–11.31%). The optimal fortified yoghurt processing and storage parameters were determined to be 0.55% lyophilised purslane, 3.41% starter culture ratios and 5 days of storage at 4°C.

Effect of Red Ginger (Zingiber officinale Rubrum) Extract on Chemical and Microbiological Characteristic of Goat Milk Yoghurt

Goat’s milk consumption (9.6 litre/capita/year) by Indonesian is still lower than cow’s milk consumption (11.8 6 litre/capita/year). One of the causes is because the goaty flavour in goat’s milk. Yoghurt is increasingly in demand, especially for people with lactose intolerance. Yoghurt is preffered because of its probiotics. Innovation in adding red ginger extract in goat milk yoghurt processing is expected can increase public interest in goat’s milk consumption. Besides being able to decrease the goaty flavour, red ginger extract could have more health benefits because of its bioactive contents. This study analysed fermentation time’s effect on the chemical and microbiological characteristics goat’s milk yoghurt (YSK) and goat’s milk yoghurt with red ginger extract (YSK EJM). This study is designed with Randomized Group Design (RGD). The first factor (A) is a different type of yoghurt, namely A1=goat's milk yoghurt without added red ginger extract and A2=goat's milk yoghurt with red ginger extract. The second factor (B) is the fermentation time (P1= 0 hours, P2= 6 hours, P3= 12 hours, P4= 18 hours, and P5= 24 hours. Data were obtained by two replications and two repititions. Ph and total titrated acid between YSK and YSK EJM were significantly different (p<0.05) after 12 hours fermentation. Total Lactic Acid Bacteria (LAB) for the two variations were different after 18 hours fermentation. Total LAB reached 106 CFU/ml for 12 hours fermentation and continuesly increased for 24 hours fermentation, YSK (5.32 x 107 CFU/ml) and YSK EJM (2.83 x 107 CFU/ml).

Set yoghurt processing with eggs as milk replacements, and improvement of texture, rheology, and microstructure by formulation design and optimisation

Eggs are suitable for the processing of set yoghurt as milk replacements, but there is no yoghurt mainly made from eggs. In the present work, production formula was designed and optimised for high-quality egg-based yoghurt processing by improving water holding capacity, aroma, texture, and taste using single factor experiment and D-optimal mixture design. Results showed that with optimised formula (whole liquid egg, 100 g; water, 180 g; sucrose, 30.89 g; diacetyl tartaric acid ester of mono(di)glycerides, 0.28 g; gelatine, 0.112 g; gellan gum, 0.14 g; and β-cyclodextrin, 0.56 g), the product showed high sensory evaluation score, fine viscosity, as well as preferable hardness and suitable fracturability. SDS-PAGE electrophoretogram indicated that the proteins in egg-based yoghurt was degraded during fermentation, which might have contributed to the improvement of gel structure and taste. Based on the SEM images, the prepared egg-based yoghurt had smoother, stronger, and more compact gel network microstructure when compared with milk-based yoghurt.

The Evaluation of Date Palm Pomace on the Physical Qualities and Acceptance of Yogurt

Date fruit is a globally important commodity that plays a significant role in the economic and political lives of date-growing areas. The date palm has phases of ripening as hababauk, kimri, khalal, rutab, and tamer. Sugar, protein, fat, minerals, ash, pectin, crude fiber, polyphenols and water, the primary components of dates. Products made from date palms include semi-finished and ready-to-use date items as well as products made from date pomace, juice, syrup, spread, and pomace. In the processing of yogurt, date palm pomace powder with concentrations of 10, 20 and 30% was applied. Date palm pomace powder has been shown to improve the chemical properties of yogurt (mineral content, pH, titrable acidity, total solids, ash, fat, protein content, and vitamin C), viscosity and syneresis. Comparisons between sample yogurts supplemented with various amounts of date palm pomace yogurt and plain yogurt were performed (control). The yogurt’s total sugar, protein, fiber, vitamin C, and mineral contents were improved by adding date palm pomace at varied quantities (10, 20 and 30%). Yogurt’s pH and lipid content were significantly lower with the addition of date palm powder. Yogurt that had date palm pomace added to it had greater viscosity and less product syneresis than control yogurt. Additionally, so that we could effectively utilize the date palm byproduct, we produced enriched, one of which was dairy, which is high in dietary fiber, minerals and antioxidants, all of which serve to mitigate the harmful effects of dairy.

Encapsulating capacity of ultra-high-pressure homogenization (UHPH): Replacement of milk fat by vegetable oils using buttermilk as a functional ingredient in yogurt processing

This study investigated the characteristics of yogurts produced by substituting dairy fat with polyunsaturated fatty acids (PUFA)-rich oils encapsulated with buttermilk (BM) in spray-dried emulsions (SDE). Two homogenization methods, conventional (CH) and ultra-high-pressure homogenization (UHPH), were compared to obtain the emulsions for spray drying. Recombined milks (RMs) were formulated using two different concentrations (4 g/100 g and 6 g/100 g) of SDE, followed by fermentation. Yogurt characteristics were evaluated during cold storage using various parameters, including coagulation properties, texture and rheology, microstructure, physicochemical characteristics (color, pH, total acidity, and water holding capacity), oxidative stability, main fatty acid profile, microbial assessment, and sensory evaluation. During cold storage, several parameters significantly influenced the yogurt characteristics. The CH yogurts exhibited higher textural parameters (firmness and consistency) and viscoelastic parameters (G′ and G'') compared to the UHPH yogurts at the same SDE concentration. However, UHPH yogurts generally showed better water holding capacity (WHC) values. UHPH yogurts also demonstrated superior stability to oxidation and higher PUFA content. The observed differences between the CH and UHPH treatments can be attributed to the structuring of fat-protein-BM into colloidal particles based on the homogenization system employed in this study. Neither of the homogenization systems nor the SDE content impacted yogurt flavor.

Comparative quality analysis and economic feasibility of solar assisted yogurt processing unit for decentralized dairy value chain

Due to the lack of farm-gate milk processing facilities, dairy farmers have to sell raw milk, resulting in economic and quality compromises. The study compared the quality of yogurt processed in solar assisted yogurt processing unit with the existing milk value chain and its techno-economic feasibility. For this, an investigation of the experiment was executed where four different milk processing approaches were compared. The quality attributes for processed milk like fat (5.283%), solid-not-fat (9.0833%), salts (0.6833%), protein (3.8%), lactose (4.1%), total solids (14.383%), pH (6.87), density (1.031 kg/L) and freezing point (− 0.532 °C) were found within the standardized ranges. Similarly, for the case of yogurt, these attributes were found as fat (5.5%), solid-not-fat (8.683%), acidity (0.93%), lactose (4.73%), total solids (14.183%), pH (4.3433), density (1.039 kg/L) syneresis (9.87 mL/100 g), S. thermophilus count range (10.18–10.30 log cfu/mL) and L. bulgaricus count range (10.26–10.34 log cfu/mL). Moreover, no detection of coliform count in solar-processed yogurt, endorsed the current idea to perform three processes of heating, fermentation, and cooling in a single unit. Based on the energy sources utilized, the payback period was calculated to be 1.3–9 years with an expected lifespan of 15 years while in terms of product profit, the payback period was predicted to be 1.78 years. The processing cost per liter of milk for yogurt production was calculated to be 0.0189 USD. Considering CO2 emission savings, it is anticipated that a solar-powered yogurt processing unit can generate 107.73 MWh of useful energy during its operating life with zero CO2 emission.

A Strategy for Rapid Acquisition of the β-D-Fructofuranosidase Gene through Chemical Synthesis and New Function of Its Encoded Enzyme to Improve Gel Properties during Yogurt Processing.

A chemical gene synthesis strategy was developed in order to obtain β-D-fructofuranosidase, and a novel gene, AlFFase3, was characterized from Aspergillus luchuensis and expressed in Escherichia coli. The recombinant protein was purified, showing a molecular mass of 68.0 kDa on SDS-PAGE, and displaying a specific activity towards sucrose of up to 771.2 U mg-1, indicating its exceptional enzymatic capacity. AlFFase3 exhibited stability between pH 5.5 and 7.5, with maximal activity at pH 6.5 and 40 °C. Impressively, AlFFase3, as a soluble protein, was resistant to digestion by various common proteases, including Flavourzyme, acidic protease, pepsin, neutral protease, Proteinase K, alkaline proteinase, and trypsin. AlFFase3 also demonstrated significant transfructosylation activity, with a yield of various fructooligosaccharides up to 67%, higher than almost all other reports. Furthermore, we demonstrated that the addition of AlFFase3 enhanced the growth of probiotics in yogurt, thereby increasing its nutritional value. AlFFase3 also improved the formation of yogurt gel, reducing the gel formation time and lowering the elasticity while increasing its viscosity, thereby improving the palatability of yogurt and reducing production costs.

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), 400IU, and 9h, respectively. This functional product can be considered an efficient food to reduce or eliminate the complications of diabetes.

The Effect of Using N2 and H2 in Milk on the Physıcochemical and Textural Properties of Yoghurt During Storage

In this study, the influences of nitrogen (N2) and hydrogen (H2) gases on the physicochemical and textural properties of yogurt during storage were investigated.
 The redox potential of the environment has been changed by using N2 and H2 which are natural methods that do not have a toxic effect on milk used in yogurt. In this way, it was determined how these reducing media changed compared to the control yoghurt. Especially H2 has made yogurt more functional with its non-toxic antioxidant feature. Redox potential is the quality parameter that affects the properties of yoghurt. The effects of this parameter on yoghurt have been revealed during storage. It has been determined in this study that quality control can be achieved by determining the effects of this quality parameter in the yoghurt process

Evaluation of the effect of different types of stabilizers and salt on improving the physico-chemical properties of camel milk yoghurt

Camel milk is recognised for its nutritional and medicinal properties. Camels are very resilient can also withstand harsh and hot climatic conditions and produce milk over a long period of time when other livestock succumb. Converting camel milk into yoghurt can increase milk shelf-life ensuring its available during drought enhancing food security. However, processing of camel milk yoghurt is challenging due to weak coagulum which has unacceptably low viscosity. The objective of this study was to evaluate the effect of different stabilisers and salt on viscosity, titratable acidity, pH, water holding capacity and syneresis of camel milk yoghurt. Camel milk was obtained from Anolei women group, Isiolo County and transported to Food Science Laboratories in Meru University of Science and Technology. The milk was assessed for quality through platform tests. Effect of two stabilisers (starch and modified starch) and a salt on yoghurt properties were evaluated. The stabilisers were added in the range of 2- 3% while salt concentration was 0.075%. The fermentation was carried out under controlled conditions in a cheese vat. After fermentation, yoghurt was analysed for the viscosity, water holding capacity, susceptibility to syneresis, tritratable acidity and change in pH over six hours during fermentation and after 7, 14 and 21 days during storage under refrigeration. The pH of yoghurt with modified starch decreased with fermentation period (1-6 hrs) from 5.8 ± 0.2 to 4.3 ± 0.2, while for yoghurt containing starch decreased from 5.8 – 4.0. The water holding capacity increased with increasing stabiliser concentration from 2-3%. The susceptibility to syneresis decreased with increasing stabiliser concentration but increased over the storage period. The viscosity increased with increasing the stabilisers concentration from 2 - 3% during fermentation. At a concentration of 3% modified starch and 0.075% salt resulted in highest viscosity (0.173±0.01 Pa.s) which is similar to that of commercial yoghurt. This study shows that it is possible to manufacture camel milk yoghurt by adding modified starch and salt to achieve similar physico-chemical properties to available commercial yoghurts.

Application Of Genetic Technology And Fruit Extracts To Improve Yogurt

Yogurt is a ubiquitous daily drink in our life, which is popular among the public because of its unique flavor and taste. Lactobacillus in yogurt is a symbiotic bacterium in human body, it promotes human health, and as probiotics is widely used in food processing industry and plays an important part in the processing and production of yogurt. Now, people's living standards are gradually improving and the pursuit of a healthy and happy life, it is particularly important to develop lactobacillus, which is more in line with the needs of human health and has more excellent traits, to improve the quality such as flavor improvement, taste enhancement and growth shelf life of yogurt. Yogurt quality is generally improved by adding some fruit / plant extract to the yogurt and mixing fermentation by lactic acid bacteria, resulting in a large improvement in flavor, taste, production time, and shelf life. Such as chitosan, bacteriocins, CMC (carboxymethylcellulose) can extend shelf life and Lotus / lily bulb powder thereby further increasing free amino acids, citric acid and free fatty acids concentrations in yogurt. And mouth feel by inducing protein-protein interactions to further increase the viscosity of yogurt; The inclusion of both grape seed extract and banana peel extract in yogurt substantially increases the post shelf life of yogurt so that nutrients are not easily lost. Moreover, mutagenesis breeding and CRISPR-Cas9 technology can obtain mutant strains with acid tolerance and weak H+-ATPase activity to avoid post-acidification.

Energy and Exergy Based Thermal Analysis of a Solar Assisted Yogurt Processing Unit

Energy and exergy based thermal analysis was conducted for a solar assisted yogurt processing unit capable of performing required heating and cooling processes in a single container. The system consisted of a round-shaped fermentation chamber connected with a hot water storage tank coupled with an evacuated tube collector and a pillow plate at the bottom of the chamber for cooling through a PV-operated refrigeration unit. Experiments were conducted using three different volumes of cow’s raw milk (30, 40, and 50 L). Energy analysis showed that 40% of the total energy was consumed during the heating process of raw milk in all cases, with an overall heat transfer efficiency of more than 80%. The specific product energy was calculated to be lower (485 kJ/kg) for the higher volume of milk (50 L). The exergy losses in the compressor of the refrigeration unit were calculated almost constant (1.0037 kW), while the exergy recovered during the refrigeration process was found in the range of 0.48–4.54 kJ/kg, 1.35–3.96 kJ/kg, and 0.84–6.18 kJ/kg for 50, 40, and 30 L of batches, respectively. Out of the total available power (2218 W) at the evacuated tube collector, 69.70% of energy was available for milk heating. The study is useful for designing optimization based on the distribution of energy and losses at various system components.

Development and Experimental Study of Smart Solar Assisted Yogurt Processing Unit for Decentralized Dairy Value Chain

Yogurt production at the farm level is important for adding value to milk. In this study, a solar-assisted yogurt processing unit capable of performing the three processes of heating, fermentation, and cooling in a single unit was developed. It consisted of a circular chamber surrounded by a coil for heating by a solar vacuum tube collector and a pillow plate for cooling by a solar PV-powered chiller unit. Experiments were performed using 50, 40 and 30 L of raw milk under a constant water circulation rate of 50 L per minute for heating followed by a cooling process under 36, 18 and 6 rpm of stirrer speeds. The heat absorption rates of the milk were 5.48–0.31, 4.75–0.16 and 4.14–0.24 kW, and the heat removal rates from water ranged from 6.28–0.49, 5.58–0.49 and 4.88–0.69 kW for 50, 40 and 30 L of milk volume, respectively. The overall heat transfer efficiency was above 80% during the heating process. A stirring speed of 18 rpm was found to be optimal in terms of cooling speed and consistency of the yogurt. The total energy consumed was calculated to be 6.732, 5.559 and 4.207 kWh for a 50, 40 and 30 L batch capacity, respectively. The study offers a sustainable energy solution for the decentralized processing of raw milk, particularly in remote areas of the developing countries where access to electricity is limited.

Physicochemical properties, sensory characteristics, and antioxidant activity of the goat milk yogurt probiotic Pediococcus acidilactici BK01 on the addition of red ginger (Zingiber officinale var. rubrum rhizoma).

Background and Aim:Yogurt contains beneficial probiotics. Addition of red ginger to yogurt as an antioxidant source becomes a way to improve the flavor and functional properties of yogurt. This study aimed to examine yogurt processing and the effect of adding red ginger (Zingiber officinale var. rubrum rhizoma), as an antioxidant source, on Pediococcus acidilactici BK01. It sought to observe the physicochemical and sensory qualities during storage (4°C).Materials and Methods:Goat milk was obtained from local farmers in Lubuk Minturun, Padang, West Sumatra, Indonesia. The yogurt was divided into two factors. Factor A was supplemented with red ginger in various concentrations: A (0% – as control), B (1%), C (2%), and D (3%). On the other hand, Factor B was subjected to variations in storage time: A (1 day), B (15 days), and C (30 days). Each treatment was conducted in triplicate. Physicochemical properties (pH, titratable acidity [TTA], and proximate analysis), sensory characteristics, and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were measured using the standard tests. The data were analyzed through analyzing multivariate (analysis of variance) supported by Duncan’s multiple range test.Results:The addition of red ginger juice increased the antioxidant activity, TTA, and water holding capacity (WHC) (p<0.05), while syneresis was significantly decreased; however, it had no effect on the total lactic acid bacteria. At the end of this research (day 30), the yogurt was still suitable for consumption, with the following composition: Antioxidant activity 48.39%, pH 4.3, TTA 1.716, water content 80%, protein 3%, fat 3%, syneresis 28%, WHC 63%, and total lactic acid bacteria 89×108 colony-forming units/mL. Furthermore, yogurt supplemented with red ginger changed its color into red blush.Conclusion:Yogurt red ginger juice is recommended as a functional drink, as it contains probiotics P. acidilactici BK01 and antioxidants to support human health. The addition of up to 3% ginger juice and a storage period of 30 days are still favored by the panelists and meet the quality standard of yogurt. We have not conducted the study on active compounds so, further research could be conducted on the components of the active compounds found in red ginger yogurt.

POTENTIAL OF USING SACCHAROMYCES BOULARDII TO PRODUCE FERMENTED MILK PRODUCTS

The analysis of the literature allows us to characterise the potential of the new probiotic yeast strain S. boulardii. The paper describes the long period of formation of fundamental knowledge and introduction of some technological methods into the production of different fermented milks products. Besides the historical aspect, the microbiological diversity of fermented milks products is considered, and the technological differences in manufacturing them are shown. It is known that yoghurt is one of the most famous fermented milk products. This dairy product has been very popular for years due to its taste characteristics and ease of manufacture. With the accumulation of knowledge about probiotics and the yoghurt production technology, there has appeared a tendency to further enrichment of the product with certain probiotics, prebiotics, and minerals. Today, yoghurt manufacturing actively uses the method of enriching the finished product with probiotics. This allows creating a qualitatively new functional food product that not only has nutritional value for the consumer, but also produces a certain positive effect on intestinal microbes and thus on the consumer’s health. Bacteria are known to be the main probiotics, but the recent discovery of the probiotic properties of certain genera and species of yeast opens up new prospects of their use, both in the pharmaceutical industry and in creating functional foods. The recently discovered yeast strain S. boulardii, phylogenetically related to S. cerevisiae, has many therapeutic effects and significant advantages over bacterial probiotics, in particular, it is resistant to antibiotics. S. boulardii is a probiotic strain that can be used to enrich yoghurt. The physiological properties of the strain and therapeutic properties of the products of its metabolism along with the technological parameters of yoghurt processing make a combination of the probiotic and this beneficial fermented milk very promising. It has been determined that to produce enriched yoghurt, it is possible to use both a lyophilised culture of S. boulardii and a microencapsulated one. On analysing the economic aspect, especially the sale of yoghurts and the further tendency towards an increase in its consumption, we can say that the introduction of S. boulardii as an enrichment strain is a promising issue of current importance.