Yogurt Products Research Articles

Low-lactose yoghurt production using β-galactosidase: An integrated study for the enzyme and its application

Lactose is broken down into easily digested simple sugars, glucose and galactose, by β-galactosidase. A low-cost β-galactosidase was successfully applied to introduce low-lactose yoghurt that is safe, affordable, and local for patients who are lactose intolerant (LI). These dairy products (DP) are already on the market, but they are fairly pricey and taste very different from regular products due to by-products of chemical reactions. LI patients require special DP to avoid the health risks associated with regular products. A concentration of 0.3% Lactobacillus paracasei β-galactosidase produced yoghurt with 2.5 g lactose 100 g−1 yoghurt, suitable for lactose-intolerant patients, allowing them to consume more DP without compromising the product's consistency, colour, or flavour. The enzyme's physicochemical, kinetic, and thermodynamic properties were thoroughly investigated. The chemical, rheological, and sensory properties of the low-lactose yoghurt produced were also assessed. Fresh yoghurt received a sensory evaluation score of 92.67, unchanged after 9 days.

Probiotic Functional Yogurt: Challenges and Opportunities

This article aims to explore the challenges and opportunities inherent in producing probiotic functional yogurt through information on the benefits of consuming this food, emphasizing its nutritional characteristics and importance for health. It explains the advantages of regular consumption, including improved digestion, gastrointestinal health, immunity, and increased absorption of minerals. The discussion focuses on the perspectives within the production of functional probiotic yogurt, with emphasis on microbial dynamics, inhibition of undesirable microorganisms, and strategies to improve the quality of this product. It highlights the challenges in maintaining the viability of probiotics during production and storage, addressing factors such as pH, exposure to oxygen, temperature regulation, and interactions between strains and ingredients. Additionally, it highlights the integration of natural compounds in probiotic functional yogurt and their sensory impacts associated with health benefits. The article is a comprehensive overview that emphasizes the critical factors that influence the fermentation process of functional probiotic yogurt and the fundamental role of probiotic viability for consumer health.

Effect of adding sodium caseinate, whey protein concentrateand milk protein concentrate on the physical, rheological and sensory properties of yogurt produced from goat milk

Yogurt is a widespread fermented dairy product widely consumed worldwide. The present study aimed to examine the impact on the yogurt's made from goat milk's physicochemical, rheological, and sensory aspects by incorporating varying percentages of Sodium Caseinate (SC), whey protein concentrate (WPC), and cow milk protein concentrate (MPC) during production to produce good quality yogurt. Four different treatments weremade and assigned as control treatment C, treatment C1 (SC was added at a percentage of 1% and 2%), treatment C2 (WPC added at a percentage of 1% and 2%), and treatment C3 (MPC added at a percentage of 1% and 2%). Estimates of pH and total acidity were among the physiochemical tests performed. Rheological evaluations includedviscosity, the ability to separate whey spontaneously, and moisture retention. Texture tests included hardness, springiness, and cohesiveness. A sensory evaluation of the produced yogurt was also done. The results showed an approximation in the additional treatments' total acidity and pH ​​values immediately after manufacturing. Compared to the control treatment, the additional treatments decreased the values of spontaneous whey separation and increased the water holding capacity and viscosity. However, the product's texture was enhanced due to the addition of the three protein components, which contributed to its hardness, springiness, and cohesion. There was an improvement in the sensory properties of the addition treatments compared to the control treatment and directly related to the increment in the addition percentage.The yogurt resulting from the addition of (SC, WPC, and MPC) led to the production of good-quality yogurt.

Evaluation of Physicochemical Properties of Yogurt Fortified with Four Verities of Common Bean Whey (Phaseolus vulgaris)

Background: In recent years, the role of novel foods in public health has rapidly grown due to increased life expectancy, rising medication costs and consumers’ focus on obtaining health benefits. Methods: This study evaluates the acid production, microbial growth, physicochemical and textural properties of common bean-fortified yogurt (CBWFY) during 28 days of cold storage. Result: All varieties of CBWFY showed higher acidity and lower pH value, resulting in a higher microbial population after production and during 28-day storage. The color values “a” and “L” did not vary significantly in all samples and remained steady after 28 days, while the “b” value increased. The highest syneresis (14.86%) was found in white bean whey, while the lowest syneresis (1.81%) was observed in kidney bean whey. In terms of texture, the cohesiveness of CBWFY and the control sample decreased, while the hardness, springiness and gumminess improved during cold storage. Remarkably, cranberry bean whey had higher values (cohesiveness, springiness and gumminess) despite the hardness found in white bean whey.

Exclusive D-lactate-isomer production during a reactor-microbiome conversion of lactose-rich waste by controlling pH and temperature

Lactate is among the top-ten-biobased products. It occurs naturally as D- or L-isomer and as a racemic mixture (DL-lactate). Generally, lactate with a high optical purity is more valuable. In searching for suitable renewable feedstocks for lactate production, unutilized organic waste streams are increasingly coming into focus. Here, we investigated acid whey, which is a lactose-rich byproduct of yogurt production, that represents a considerable environmental footprint for the dairy industry. We investigated the steering of the lactate-isomer composition in a continuous and open culture system (HRT = 0.6 d) at different pH values (pH 5.0 vs. pH 6.5) and process temperatures (38°C to 50°C). The process startup was achieved by autoinoculation. At a pH of 5.0 and a temperature of 47°C-50°C, exclusive D-lactate production occurred because of the dominance of Lactobacillus spp. (> 95% of relative abundance). The highest volumetric D-lactate production rate of 722 ± 94.6 mmol C L−1 d−1 (0.90 ± 0.12 g L−1 h−1), yielding 0.93 ± 0.15 mmol C mmol C−1, was achieved at a pH of 5.0 and a temperature of 44°C (n = 18). At a pH of 6.5 and a temperature of 44°C, we found a mixture of DL-lactate (average D-to-L-lactate production rate ratio of 1.69 ± 0.90), which correlated with a high abundance of Streptococcus spp. and Enterococcus spp. However, exclusive L-lactate production could not be achieved. Our results show that for the continuous conversion of lactose-rich dairy waste streams, the pH was a critical process parameter to control the yield of lactate isomers by influencing the composition of the microbiota. In contrast, temperature adjustments allowed the improvement of bioprocess kinetics.

Effect of Milk Origin and Seasonality of Yogurt Acid Whey on Antioxidant Activity before and after In Vitro Gastrointestinal Digestion.

Yogurt acid whey (YAW) is a by-product of Greek strained yogurt production. The disposal of YAW constitutes an environmental problem, and given the increasing demand of Greek yogurt worldwide, its handling is a challenge. However, whey-derived peptides, resulting from microbial fermentation as well as those resulting from further hydrolysis during the digestion process, have been linked to enhanced biological activities. In this study, the antioxidant capacity of 33 samples of YAW obtained from Greek dairy companies of bovine, ovine or caprine origin was investigated using both cell-free and cell-based assays. The YAW samples, their in vitro digestion products (YAW-Ds) and a fraction of the digests (less than 3 kDa; YAW-D-P3) were assessed using four biochemical assays, namely ORAC, ABTS, FRAP and P-FRAP. Our data revealed a higher antioxidant capacity for digested samples compared with undigested samples, with all four methods. ORAC values after in vitro digestion were higher for the ovine samples compared to their bovine (YAW-D and YAW-D-P3) and caprine (YAW-D-P3) counterparts. Furthermore, the YAW-D-P3 fraction derived from samples collected in the summer months exhibited higher ORAC values when compared to the respective fraction from the winter months' samples. The cellular antioxidant activity of ovine YAW-D-P3 was improved in H2O2-treated HT29 cells compared to the control H2O2-treated cells. However, YAW-D-P3 could not trigger either the pathways involving the transcription factors NF-κB or NFE2L2 or the gene expression of SOD1, CAT and HMOX1 in LPS-challenged THP-1-derived macrophages. These results suggest that YAW, and particularly YAW from ovine origin, could be used as a natural source for its antioxidant potential in human and animal nutrition.

Sugar content in yogurts: What information is provided to consumers on the label?

This study focused on the observational and descriptive analysis of yogurt products available in major supermarket chains across Uruguay. A database of 120 yogurts was established using the FLIP-LAC program, facilitating the collection, storage, and analysis of packaging information. The findings revealed a diverse range of yogurts based on fat content, with 18% being whole, 49% low-fat, and 33% non-fat. Significantly, 97% of the yogurts contained sugar or alternative sweeteners, aligning with global trends and highlighting the prevalent use of sweetening agents in dairy products. The study underscored the challenges in assessing sugar intake due to the non-mandatory declaration of sugar content in nutritional labeling. Notably, 3% of yogurts did not contain any sweeteners or sugar. Additionally, 10% of the yogurts displayed an excess sugar warning octagon, indicating sugar content exceeding 26 g per serving. The study emphasized the need for enhanced nutritional education and public policies to empower consumers in making informed dietary choices. Despite regulatory efforts, the absence of mandatory sugar declarations on nutritional labels hinders consumers from tracking and managing their sugar intake effectively. The dataset revealed significant differences in sugar content-based categories on fat content, highlighting potential avenues for industry improvement in producing healthier yogurt options.

Effect of modified okara insoluble dietary fibre on the quality of yoghurt

The aim of this study was to investigate the potential of adding soya bean dregs insoluble dietary fibre (IDF) modified by jet cavitation combined with cellulase to yoghurt to improve its functional properties (Yoghurt was prepared by adding 10 μL of yoghurt fermenter to 100 mL of milk, fermented to pH 4.5 in a constant temperature incubator at 42 °C, and then stored in a refrigerator at 4 °C after adding IDF separately). The results showed that the modified IDF had a rough structure with high water-holding capacity and sodium cholate adsorption capacity. The addition of modified IDF improved the pH, hardness, and elasticity of the yoghurt. During the entire storage period, the titratable acidity and whey precipitation rate of the modified IDF yoghurt gradually increased, and antioxidant activity gradually decreased, and its titratable acidity, whey precipitation rate, and antioxidant activity had a significant advantage compared with those of the blank group yoghurt. In conclusion, the modified soya bean dregs IDF-added yoghurt prepared by jet cavitation combined with the cellulase method has the potential for sodium cholate adsorption capacity and antioxidant activity, which can confer unique functional properties and improve the pH, texture, and reduce whey precipitation of yoghurt. This study provides a scientific basis for the application of soya bean dregs IDF as a fibre fortifier in yoghurt production and suggests innovative ideas for the design of functional dairy products.

Nutritional and Sensory Evaluation of Yoghurt Incorporated with Unripe False Horn Plantain (Musa paradisiaca var. "apentu").

Unripe plantain (Musa paradisiaca L.) is rich in nutrients including minerals, vitamin C, and carbohydrates particularly resistant starches with prebiotic properties. However, the fruit is challenged with limited utilisation, and this contributes to its high postharvest losses along the production and supply chain. Information is lacking on incorporating plantain (UPF) in functional dairy food product development. In a completely randomized design, the study evaluated the effect of unripe false horn plantain (var. "apentu") flour (UPF) incorporation (w/v), at 0% (control), 2%, 4%, and 6%, on the composition and sensory quality of yoghurt. The results showed that higher UPF percent incorporation resulted in yoghurts having lower moisture and higher total solid values as well as enhanced nutritional values, in terms of protein, zinc, potassium, calcium, and vitamin C (P < 0.05). Mean pH and total titratable acidity values of the yoghurt products were in the ranges of 3.40-3.65 and 1.00-130%, respectively. Conversely, an increase in UPF incorporation generally reduced consumer likeness scores for yoghurt sensory characteristics including appearance, texture, flavour, taste, aftertaste, and overall acceptability. The control AZ product received the highest ratings in all sensory attributes evaluated. Compared with the control AZ, the BX (2% w/w UPF) yoghurt showed better nutritional quality as well as had comparable ratings for the sensory attributes, particularly in terms of appearance, texture, and flavour. Thus, the formulation containing 2% UPF has the best potential for the production of value-added functional yoghurt, which will be acceptable. However, for high acceptability, further research is needed to improve the impact of UPF incorporation on the overall sensory quality of yoghurt. The study suggests that UPF can serve as a potential supplement for improving the value of yoghurt, and this also contributes to reducing postharvest losses of plantain as a key food security resource. Also, the study findings contribute baseline information to guide future research on functional dairy product development with unripe plantain.

Soybean hull polysaccharides affect the physicochemical properties and lactic acid bacteria proliferation in plant‐based yogurt

AbstractAs a by‐product of soybean processing, soybean hulls contain soybean hull polysaccharides (SHPS). This study aims to develop a plant‐based yogurt with SHPS addition and assess the consequences of SHPS on the physicochemical properties and growth of lactic acid bacteria (LAB) in yogurts. The study investigated the water holding capacity (WHC), microstructure, rheological properties, texture, pH, organoleptic attributes, volatile compounds, flavor profile, and LAB population. The findings reveal that the addition of SHPS significantly impacted these properties. SHPS improved the physicochemical properties, increased the level of flavor compounds, and improved the organoleptic properties of yogurt. Yogurt with 0.6% SHPS demonstrated superior WHC, texture, rheological properties, and the highest organoleptic evaluation scores. However, when SHPS additions exceeded 0.6%, WHC, texture, and rheological properties of the yogurts decreased. Furthermore, SHPS‐added yogurts contained more LAB compared to yogurt without SHPS. LAB grew better in media with SHPS than in media without glucose. Streptococcus thermophilus grew best among the LAB strains. This study highlights the potential of SHPS in yogurt production and its promising applications in fermented food products.

Sensory drivers of liking, emotions, conceptual and sustainability concepts in plant-based and dairy yoghurts

Replacing animal-based protein food products with plant-based protein products is essential for human health and the environment. For this reason, a number of plant-based (PB) yoghurts have been developed to replace dairy yoghurt. However, many of these products suffer from poor sensory quality. In order to improve the quality of these products, data on the sensory drivers of liking, emotional, and conceptual responses to PB yoghurts, PB alternatives (PB blends, PB/dairy blends) and dairy yoghurts are required. In addition, in order to optimise the design of these products for sustainability-oriented consumers, research is needed on the drivers of consumers’ conceptualisations of sustainability. To provide actionable product development guidance on these issues, multi-attribute research was undertaken in a central location test with New Zealand consumers, using a variety of commercial PB and dairy yoghurts (blind sample presentation) that were expanded in their range of sensory attributes through ingredient modifications, with the goal of quasi-replicating and extending prior research on the sensory drivers of liking, emotions, and conceptualisations of PB yoghurts. Results of the research confirmed previous literature findings on the sensory drivers of liking and non-sensory variables in the PB yoghurt space. Among the salient findings related to sensory drivers are that white and lighter coloured yoghurts with smooth and creamy appearance and mouthfeel, sweet taste, and vanilla or coconut flavours maximise liking and positive emotional responses to yoghurt products. In addition, a number of these and other sensory characteristics elicited specific positive conceptualisations of the yoghurts. Although sustainability conceptualisations were evoked less frequently, the major positive drivers of these conceptualisations were “white colour,” “sweet,” “even/smooth” appearance and texture, “oat-like flavour” and “coconut flavour.” “Dairy flavour” evoked conceptualisations related to “traditional” and “authentic,” but also elicited a number of negative sustainability concepts, such as “resource intensive,” “commercially farmed raw materials” and reduced conceptualisation of “animal friendly.” Other important sensory drivers of liking, emotions and conceptualisations are discussed, providing consumer insights and direction to product developers in their efforts to improve the sensory characteristics, acceptance and consumption of PB and other alternative yoghurt products.

Impact of Storage Conditions of Yogurt Dry Ingredients on the Physicochemical Properties of the Final Product

This study investigated the impact of storage conditions of the ingredients for yogurt production on the rheological and physicochemical characteristics of the final fermented product. The novelty is the application of a special mix of milk protein concentrate and sodium caseinate for yogurt production. Separately exposing the protein mix powder and bacteria culture to 20 °C caused considerable changes in the obtained yogurt stiffness and the incubation times required to produce the gel due to a decrease in bacterial count. Minimal changes in bacteria viability were observed after storage at 5 °C. Lower temperature and shorter storage times increased yogurt firmness, viscosity, and storage modulus, resulting in a smoother and more viscous product. A linear correlation was found between yogurt firmness and water activity. Powders stored at lower temperatures and for shorter times produced yogurt with stronger texture and better water binding. Additionally, yogurt obtained from dry ingredients stored under these conditions required shorter incubation times. Storing the starter culture at 5 °C for at least 8 weeks had no significant effects on the physicochemical properties or incubation time requited to produce the final yogurt. This work highlights the importance of storage conditions of yogurt dry ingredients in maintaining the quality of the final product.

Response surface optimization of thermo-sonication conditions and taro mucilage concentrations for the preparation of soy yogurt

The present study embarked on developing soy yogurt utilizing soybean and taro mucilage. Box-Behnken Design (BBD) of Response Surface Methodology (RSM) was executed to optimize the ingredient and thermo-sonication conditions such as temperature (A: 40–60 °C), time (B: 5–15 min), and mucilage concentrations (0.1–0.3 g/100 mL) on the responses such as pH, acidity, syneresis, water holding capacity, viscosity, texture profile (firmness, adhesiveness, gumminess), and overall acceptability. The analyses showed that the soy yogurts have a titratable acidity (0.73 ± 0.43 % - 0.85 ± 0.58 %), pH (4.7 ± 0.40–4.93 ± 0.68), total soluble solid (26 ± 3.2 °Brix - 42.2 ± 4 °Brix), syneresis (26 ± 3.2 % - 39.98 ± 3.7 %), water holding capacity (36.33 ± 4.91 % - 55.7 ± 2.27 %), viscosity (1367.3 ± 2.98 mPa s - 2306.13 ± 3.21 mPa s), whitening index (76.1 ± 3.22–82.33 ± 2.18), firmness (14 ± 5 g - 26 ± 2 g), cohesiveness (13 ± 3.74 g s - 23.2 ± 2.88 g s), gumminess (0.7 ± 0.01 g - 1.8 ± 0.03 g), and overall acceptability (3.96 ± 0.16–4.54 ± 0.32). From the variance analysis, the R2 of eleven response variables is more than 0.85, which indicates the model explained a high proportion of variability. At 60 °C thermo-sonication temperature, 13 min thermo-sonication time, and 0.3 g/100 mL mucilage concentration, the optimal conditions recorded for 0.780 ± 0.21 % (titratable acidity), 4.701 ± 0.51 (pH), 10.986 ± 0.76 °Brix (total soluble solid), 27.886 ± 0.49 % (syneresis), 54.687 ± 0.38 % (water holding capacity), 1810.541 ± 5.75 mPa s (viscosity), 23.126 ± 0.45 (firmness), 16.945 ± 0.21 (cohesiveness), 1.485 ± 0.48 (gumminess), 81.764 ± 0.32 (whitening index), and 4.365 ± 0.42 (overall acceptability). Furthermore, the developed models' actual response and predicted values correlated with each other as the Residual Standard Error (RSE) values were ≤5 %. This suggests that our model can reliably guide the selection of optimal parameters for any combination of factors. Ultimately, the insights garnered from this study hold promise for the large-scale production of taro mucilage-based soy yogurt, offering a versatile and nutritious addition to the repertoire of dairy alternatives.

Investigating the impact of exopolysaccharides on yogurt network mechanics and syneresis through quantitative microstructural analysis

Exopolysaccharides produced by lactic acid bacteria are widely used to improve the sensory properties of yogurt. The relation between the physical properties of the microbial exopolysaccharides and the structural and rheological properties of the yogurt are incompletely understood to date. To address this knowledge gap, we studied how two distinct exopolysaccharides influence the microstructure, rheological properties, and syneresis of yogurt. The effect of a negatively charged, capsular exopolysaccharide produced by Streptococcus thermophilus and a neutral, non-capsular exopolysaccharide produced by Lactococcus lactis were investigated. Using quantitative microstructural analysis, we examined yogurt samples prepared with either the capsular or the non-capsular exopolysaccharide, and with mixtures of the two. Confocal laser scanning microscopy and stimulated emission depletion microscopy were employed to visualize the microstructures, revealing differences in pore size distribution, protein domain size, and casein interconnectivity that were not apparent through visual inspection alone. Additionally, variations in rheological properties were observed among the different yogurt types. In the yogurt fermented with both bacterial strains, we observed a combined impact of the two exopolysaccharide types on relevant microstructural and rheological properties. The negatively charged capsular exopolysaccharide enhanced casein interconnectivity and gel stiffness, while the neutral non-capsular exopolysaccharide led to thicker protein domains, an abundance of small pores, and a lower loss tangent. These factors collectively hindered syneresis, resulting in improved structural integrity. Our study not only provides valuable insights into the influence of different exopolysaccharides on yogurt properties, but also presents the first demonstration and quantification of the effect of multiple types of exopolysaccharides on casein interconnectivity. These findings offer guidance for the production of yogurts with customized microstructure, rheological properties, and resistance to syneresis.

Bee Bread Boosts Probiotic Yoghurt: Unveiling the Impact on Physiochemical, Microbiological, and Sensory Attributes

This study aimed to investigate the effects of bee bread on some parameters in probiotic yoghurt production. The bee bread composition contained the elements B, Ca, Fe, K, Mg, Na, P, and Zn. The analysis of sugar composition revealed the presence of fructose, glucose, and sucrose. The organic acid and phenolic substance content were assessed. The following values were obtained: oxalic acid (1.26 mg/g), malic acid (7.79 mg/g), ascorbic acid (0.91 mg/g), citric acid (2.73 mg/g), p-coumaric acid (15.3 µg/g) and kaempferol (5,562.4 µg/g). The study determined the tocopherol content, specifically alpha (7.09 µg/g), beta (0.4 µg/g), gamma (0.77 µg/g), and delta (0.31 µg/g). A total of 55 distinct components were identified while analyzing the volatile and aroma profiles. This study found that the IC50 value of bee bread was 1.414 mg/mL. Bee bread did not affect physicochemical parameters such as pH, acidity, dry matter, ash, milk fat, and water holding capacity (P&gt;0.05) but affected protein and syneresis (P

Utilization of pomegranate and black grape seed by-products in yogurt production: Effects on phenolic compounds and antioxidant activity.

The present study investigated the potential utilization of pomegranate and black grape seed by-products of the food industry in yogurt production. Specifically, we examined the effect of polyphenols on antioxidants in yogurts produced using two different starter cultures: classical yogurt culture (Lactobacillus delbrueckii subsp. bulgaricus + Streptococcus thermophilus) and yogurt culture supplemented with L. casei. Various parameters, including pH, acidity, viscosity, fat content, protein content, dry matter content, color, microbiological properties, and sensory attributes, were analyzed in the yogurt products. The present findings indicate that incorporating pomegranate and grape seed powder and using different starter cultures significantly affected the yogurt's phenolic content and antioxidant activity. Furthermore, we observed decreased phenolic content and antioxidant activity during the 21-day storage period. Interestingly, yogurts produced with pomegranate seed powder and L. casei culture exhibited higher antioxidant activity than the other samples. Importantly, none of the yogurts containing pomegranate and grape seed powders had microbial counts below 107 cfu/g for L. delbrueckii subsp. bulgaricus, S. thermophilus, and L. casei, indicating no adverse effects on probiotic properties. Sensory evaluation revealed that the yogurt product prepared with grape seed powder and a combination of yogurt culture (L. delbrueckii subsp. bulgaricus + Streptococcus thermophilus) and L. casei was particularly well-received. In conclusion, the functional properties of grape seed powder and pomegranate seed powder make them suitable natural ingredients for enhancing the antioxidant activity of yogurt. The study highlights the potential of utilizing these by-products to develop yogurt products with added health benefits.

Segmenting, Targeting, and Positioning of Yogurt Products From the Perspective of Islamic Marketing

This study aims to explore the concept of Islamic marketing strategy and its potential role in developing halal trade and contributing towards the achievement of Sustainable Development Goals (SDGs). The research method use qualitative method, a literature review is conducted to examine Islamic marketing from a marketing strategy perspective, building on the STP framework and outlining its implications. The findings suggest that Sharia-compliant marketing can serve as an effective strategy for businesses to attract customers using halal marketing tactics in their Segmentation, Targeting, and Positioning approaches. This approach enables the business world to avoid being perceived as solely profit-driven and instead embrace social responsibility. The proposed framework can be utilized by businesses to segment the Muslim market given the cultural dissimilarities in interpreting Islam and halal. This way, companies can not only comprehend the diverse segments within Islamic interpretation, but also devise an appropriate marketing mix to cater to consumer requirements. The study's findings can be applied to Muslim marketers while using the Segmenting, Targeting, Positioning framework. Furthermore, it offers qualitative guidance for non-Muslim marketers and scholars, resolving various marketing-related concerns.

Study of the Physiochemical and Sensory Properties of Therapeutic Low-Cholesterol Yoghurt Fortified with Zinc Nanoparticles

The objective of this research is to develop a yoghurt enriched with B-cyclodextrin-based nano-coated, uncoated, and low-cholesterol additives. The objective of this study is to assess the impact of fortification on the physicochemical and sensory characteristics of yoghurt. This will be achieved by fortifying raw milk with varying concentrations of nano-zinc., which are 15, 7.5, 3.75 mg / 100 mL The treatments T4, T3, and T2 are denoted as such,, along with the treatment. of yogurt fortified with zinc nanoparticles, which is not coated, represents the treatment T1 and the control treatment, denoted as C, involved the production of yoghurt using milk as the primary ingredient. that was not fortified with zinc nanoparticles. Chemical, physical and rheological tests were conducted in addition to sensory the evaluation will be conducted promptly following the completion of manufacturing and subsequent storage at a controlled temperature range of (1 ± 5) degrees Celsius for a duration of 21 days. The findings indicated that there were no statistically significant disparities in the levels of fat, protein and ash. As for the values of moisture and carbohydrates there were notable disparities observed between the control treatment and the remaining treatments. The total acidity and pH values exhibited minimal variation across all yoghurt treatments. Yogurt treatments fortified with nano-encapsulated zinc were characterized by lower values in ADV and pV. The addition of zinc to yoghurt resulted in enhancements in rheological properties, specifically in terms of spontaneous whey perfusion and viscosity. The experimental group achieved higher scores and demonstrated superior performance in all sensory characteristics when compared to the control treatment, denoted as treatment C.

Identification of Previously Unrecorded Bacills, Serratia, and Mucor Strains Isolated from Yogurt

(1) Background: Foodborne illnesses are recognized as a significant threat to public health and the economy in both developed and developing nations. The safety of foods containing microorganisms has consequently become a major worldwide concern. One of the most frequent causes of food deterioration in the world is microbial contamination. (2) Methods: Yogurt containers that were bought commercially in Riyadh, Saudi Arabia during their validity period contained four different species of bacteria and one type of fungus. Using nutritional agar and Czapek-Dox agar medium, the bacteria and fungi were isolated. The isolates of the fungi and bacteria were identified using a scanning microscope. The isolates were further identified and classified for molecular evolutionary analyses using the 16S rRNA and ITS sequences from the bacteria and fungi, respectively, in conjunction with the universal primers 27F, 1492R, ITS1F, and ITS4R. (3) Results: A total of 131 separate strains were identified from 12 yogurt samples based on their phenotypic characteristics. In total, 79 isolates (60.3%) consisted of Serratia marcescens, Bacillus subtilis, and Mucor circinelloides, with 52 isolates (39.7%) being Bacillus cereus. While the cells of Bacillus and Serratia are shaped like rods, the sporangia of Mucor are large, round, and black. Each strain was identified by its accession number, which were as follows: MK590996.1: B. cereus; MK591144.1: B. subtilis; MK591002.1 and MK591014.1: S. marcescens; and MK559692.1: M. circinelloides. The maximum identification was found to be between 98.64 and 100% when BLAST was used to compare the sequences to the NCBI GeneBank database. (4) Conclusions: Genus and species identification was performed using the similarity score values. Yogurt products containing high concentrations (39.7%) of Bacillus cereus isolates carry a significant risk of health hazards due to the potential for spreading pathogenic bacteria to humans.

Can Dawul Kurundu (Neolitsea involucrate) leaf extract be used as a plant-based stabilizer in set yoghurt production?

The incorporation of plant-derived stabilizers in food processing and preservation has gained considerable industrial interest. The leaf extract of Neolitsea involucrate, Dawul Kurundu (DK), has proven to be a potent plant-derived stabilizing agent in the food industry. However, the potential of utilizing DK leaf extract in the dairy industry has not yet been proven. Thus, the feasibility of incorporating DK leaf extract in set yoghurt production by assessing its physicochemical, sensory, proximate composition, minerals (calcium and phosphorous), and microbial (Escherichia coli, yeast, and mold) quality parameters during storage at 4°C up to 21 days was assessed. DK leaf aqueous extracts of 0.4% w/v (T2), 0.6% w/v (T3), and 0.8% w/v (T4) were used for testing with the control sample, 0.6% gelatin (T1). Compared to T1, there were no differences in color, taste, texture, and mouthfeel in all DK leaf extract-incorporated yoghurts, demonstrating the suitability of using DK leaf extract to replace the gelatin. A decreasing pattern of pH value was observed during 21 days of the storage period in all treatments, whereas total titratable acidity increased significantly with time. Furthermore, the lowest syneresis value was obtained by T4, demonstrating ideal stabilizing properties at higher incorporation levels. The proximate, mineral, and microbial compositions of all treatments showed no significant difference compared to the control. Therefore, overall results revealed that the 0.8% w/v level of DK leaf extract incorporation (T4) could be used as a potent stabilizer in set yoghurt production by allowing the possibility of replacing the gelatin without compromising its organoleptic properties. Improved and efficient methods for extracting the DK leaf extracts by focusing on their potential functional and health effects should be further examined.