Search Results (154)

Monitoring pH and acidity during yoghurt fermentation is essential for product quality and process efficiency. Conventional measurement methods, however, are invasive and labour-intensive. This study developed artificial neural network (ANN) models to predict pH and titratable acidity during yoghurt fermentation using CIELAB colour parameters (L, a*, b*). Reconstituted milk powder with 12% total solids was prepared with varying protein levels (4.2–4.8%), inoculum concentrations (1–3%), and fermentation temperatures (36–44 °C). Data were collected every 10 min until pH 4.6 was reached. Forty models were trained for each output variable, using 90% of the data for training and 10% for validation. The first two phases of the fermentation process were clearly distinguishable, lasting between 4.5 and 7 h and exceeding 0.6% lactic acid in all treatments evaluated. The best pH model used two hidden layers with 28 neurons (R² = 0.969; RMSE = 0.007), while the optimal acidity model had four hidden layers with 32 neurons (R² = 0.868; RMSE = 0.002). The strong correlation between colour and physicochemical changes confirms the feasibility of this non-destructive approach. Integrating ANN models and colourimetry offers a practical solution for real-time monitoring, helping improve process control in industrial yoghurt production. Full article

Noncommunicable diseases (NCDs) like diabetes and cancer drive demand for therapeutic functional foods. This study developed freeze-dried fermented camel milk (FCM) with Ajwa date pulp (ADP), evaluating its physical and functional properties, probiotic survival, and potential benefits for diabetes and cancer. To achieve this target, six FCM formulations were prepared using ABT-5 starter culture (containing Lactobacillus acidophilus, Bifidobacterium bifidum, and Streptococcus thermophilus) with or without Lacticaseibacillus rhamnosus B-1937 and ADP (12% or 15%). The samples were freeze-dried, and their functional properties, such as water activity, dispersibility, water absorption capacity, water absorption index, water solubility index, insolubility index, and sedimentation, were assessed. Reconstitution properties such as density, flowability, air content, porosity, loose bulk density, packed bulk density, particle density, carrier index, Hausner ratio, porosity, and density were examined. In addition, color and probiotic survivability under simulated gastrointestinal conditions were analyzed. Also, antidiabetic potential was assessed via α-amylase and α-glucosidase inhibition assays, while cytotoxicity was evaluated using the MTT assay on Caco-2 cells. The results show that ADP supplementation significantly improved dispersibility (up to 72.73% in FCM15D+L). These improvements are attributed to changes in particle size distribution and increased carbohydrate and mineral content, which facilitate powder rehydration and reduce clumping. All FCM variants demonstrated low water activity (0.196–0.226), indicating good potential for shelf stability. The reconstitution properties revealed that FCM powders with ADP had higher bulk and packed densities but lower particle density and porosity than controls. Including ADP reduced interstitial air and increased occluded air within the powders, which may minimize oxidation risks and improve packaging efficiency. ADP incorporation resulted in a significant decrease in lightness (L*) and increases in redness (a*) and yellowness (b*), with greater pigment and phenolic content at higher ADP levels. These changes reflect the natural colorants and browning reactions associated with ADP, leading to a more intense and visually distinct product. Probiotic survivability was higher in ADP-fortified samples, with L. acidophilus and B. bifidum showing resilience in intestinal conditions. The FCM15D+L formulation exhibited potent antidiabetic effects, with IC₅₀ values of 111.43 μg mL⁻¹ for α-amylase and 77.21 μg mL⁻¹ for α-glucosidase activities, though lower than control FCM (8.37 and 10.74 μg mL⁻¹, respectively). Cytotoxicity against Caco-2 cells was most potent in non-ADP samples (IC₅₀: 82.22 μg mL⁻¹ for FCM), suggesting ADP and L. rhamnosus may reduce antiproliferative effects due to proteolytic activity. In conclusion, the study demonstrates that ADP-enriched FCM is a promising functional food with enhanced probiotic viability, antidiabetic potential, and desirable physical properties. This work highlights the potential of camel milk and date synergies in combating some NCDs in vitro, suggesting potential for functional food application. Full article

Acetate is naturally produced in the rumen through feed degradation and fermentation. It serves as a primary energy source for ruminants and as a key substrate for de novo fatty acid synthesis in the mammary gland. The interaction of exogenous acetate with different animal and dietary factors is an area of growing interest, as it may have significant implications for milk fat synthesis. This study aimed to assess the effect of two diet fermentability levels on the short-term response of lactation to acetate supplementation in dairy cows. Eight ruminally cannulated multiparous European Holstein cows were randomly assigned to treatments in a crossover design that tested the effect of diet fermentability, acetate supply, and their interaction. Using corn silage as the only forage source and a constant forage-to-concentrate ratio, high-fermentability (HF) and low-fermentability (LF) diets were formulated. Acetate supply was investigated by infusing ruminally 10 moles of sodium acetate/d (ACE) or an equimolar infusion of control (CON). Therefore, the treatments were as follows: LF + CON; LF + ACE; HF + CON; and HF + ACE. No interactions between acetate and diet fermentability were found on performance variables. Acetate infusion decreased dry matter intake (DMI), milk yield, and milk protein yield and content but did not affect milk fat yield; however, it increased milk fat concentration, and this response tended to be more pronounced in the HF diet. Acetate infusions increased plasma β-hydroxybutyrate in the HF diet, but not in the LF diet, and increased plasma non-esterified fatty acid, which was likely a lipolysis response to reduced DMI and decreased energy balance. This study demonstrates that acetate availability can be a constraint on mammary lipogenesis, even with adequate dietary fiber. Full article

Buffalo milk is a rich source of precursor fatty acids for bioactive compounds and provides an optimal environment for bacterial growth. This study aimed to isolate and select lactic acid bacteria strains with potential to conjugated linoleic acid (CLA) production for technological application in fermented buffalo milk. Fifty-eight strains were isolated from raw milk, kefir, artisanal cheese, kombucha, and jaboticaba juice and tested for CLA biosynthesis. In milk fermentation, selected strains with linoleic acid (LA) conversion rates ranging from 65.66% to 21.86% were L. paraplantarum, L. plantarum, P. pentosaceus, and L. fermentum. The highest viability average values between 11.85 and 11.15 Log CFU/mL were observed after 8 h of fermentation for the L. plantarum, control L. plantarum, and L. fermentum treatments, while it took 10 h of fermentation for L. paraplantarum and P. pentosaceus to reach a stationary phase, with pH stabilizing at 4.60 ± 0.1 after 30 h. Despite L. paraplantarum showing the highest in vitro CLA production (0.99 mg/mL), in buffalo milk, all strains similarly produced c9t11 CLA, with no detectable t11c12 CLA. P. pentosaceus and L. fermentum showed a fatty acid profile with higher PUFA content, especially in CLA and MUFA, related to a lower degree of atherogenicity (IA) and thrombogenicity index (ThI). These findings boost understanding of dairy (raw milk, artisanal cheese, and milk kefir) and non-dairy substrates (kombucha and jaboticaba juice) as reservoirs for functional bacteria and highlight buffalo milk as a matrix for diversification of naturally enriched fermented dairy products. Full article

This study examines the fermentation performance of featured bacteria (Lactobacillus acidophilus-ATCC-4356, Lactobacillus helveticus-ATCC-15009, Lactobacillus delbrueckii subsp. bulgaricus-ATCC-11842, Lacticaseibacillus casei-ATCC-393, Streptococcus thermophilus-ATCC-19258 (ST), and Bifidobacterium bifidum-ATCC-29521 (BB)) used in fermented dairy products and their impact on product quality. The main focus is on evaluating the metabolic activities, organic acid production, viscosity values, and sensory properties of probiotic strains such as L. acidophilus, L. bulgaricus, L. casei, L. helveticus, B. bifidum, and S. thermophilus. The strains were activated in a sterile milk medium and incubated until they reached a pH of 4.6. Then, pH, microbial enumeration, organic acid, sugar composition, vitamins A, D, E, K1, and K2 (menaquinone-7), and viscosity values were measured in the bacteria. Organic acid, sugar composition, and vitamins A, D, E, K1, and K2 (menaquinone-7) were analyzed with the HPLC method. Additionally, sensory analyses were performed, and volatile compounds were examined. L. casei demonstrated superiority in lactic acid production, while L. helveticus showed high lactose consumption. L. bulgaricus stood out in galactose metabolism. The highest viscosity was observed in products produced by B. bifidum. Differences in viscosity were attributed to exopolysaccharide (EPS) production and acid production capacity. A total of 62 volatile compounds were identified, with the highest levels of aromatic components found in products containing B. bifidum. The most preferred product, based on panel evaluations, was the fermented dairy product produced with L. acidophilus. As for aroma profiles, it was determined that the phenethyl alcohol, 3-methyl-1 butanol, and ethanol compounds are associated with B. bifidum, the hexanoic acid and 2-methylbutanal compounds are associated with the L. acidophilus, the hexanoic acid, 2-methylbutanal, 2-furanmethanol, and acetaldehyde compounds are associated with the L. bulgaricus, and the hexanoic acid, 2-methylbutanal, 2-heptanone, acetoin, and d-limonene are associated with the L. casei. On the other hand, the L. helveticus strain is associated with the hexanoic acid, 2-methylbutanal, and 2-heptanone, and the S. termophilus strain is associated with the hexanoic acid, hexanol, acetoin, 2,3-pentanedione, 1-butanol, and 3-methyl-2-butanone volatile aroma compounds. The determination of fat-soluble vitamins is particularly important for vitamin K1 and vitamin K2. In this study, the bacterial sources of these vitamins were compared for the first time. The menaquinone-7 production by L. helveticus was determined to be the highest at 0.048 µg/mL. The unique metabolic capacities of these prominent cultures have been revealed to play an important role in determining the aroma, organic acid content, viscosity, and overall quality of the products as a whole. Therefore, the findings of this study will provide the right strain selection for a fermented dairy product or a different non-dairy-based fermented product according to the desired functional properties. It also provides a preliminary guide for inoculation in the right ratios as an adjunct culture or co-culture for a desired property. Full article

This review contributes to the knowledge on the complex and adaptive microbial ecosystems within cheese, emphasizing their critical role in determining cheese quality, flavor, and safety. This review synthesizes the current knowledge on the microbial interactions and the dynamics of lactic acid bacteria (LAB), encompassing both starter (SLAB) and non-starter (NSLAB) strains, which are pivotal to the curd fermentation and ripening processes. The adaptability of these microbial consortia to environmental and technological stressors is explored, highlighting their contributions to acidification, proteolysis, and the development of distinctive organoleptic characteristics. Historical and technological perspectives on cheesemaking are also discussed, detailing the impact of milk treatment, starter culture selection, and post-renneting procedures on microbial activity and biochemical transformations. This review underscores the importance of microbial diversity and cooperative interactions in fostering ecosystem resilience and metabolic functionality, and it addresses the challenges in mimicking the technological performance of natural starters using selected cultures. By understanding the ecological roles and interactions of cheese microbiota, this review aims to guide improvements in cheese production practices. Additionally, these insights could spark the development of innovative strategies for microbial community management. Full article

The growing demand for sustainable food systems has led to significant advancements in developing alternatives to animal-derived products. Dairy products are an important dietary source of proteins and fats; however, their production raises environmental concerns, including greenhouse gas emissions, extensive land and water usage, and biodiversity loss. Therefore, there is a need to develop sustainable, scalable solutions that will enable the production of quality replacements for animal-based foods with reduced environmental impacts. Recognizing that replacing animal-based products from a single source is currently not feasible; there is a need for high-quality sources of ingredients that can be combined to mimic the holistic product. In recent years, plant-based dairy alternatives have gained traction; however, their inability to replicate the sensorial experience of real milk—attributed largely to the unique composition and structure of milk fat—remains a key limitation. Cow’s milk fat has distinctive characteristics, including a complex fatty acid profile, which is rich in short- and medium-chain saturated fatty acids with specific positional distribution. These characteristics of cow’s milk play a role in delivering the aroma, texture, and mouthfeel of dairy products. Recent efforts have focused on leveraging precision fermentation and cellular agriculture to mimic these properties. This review explores the unique lipid composition of ruminant milk, the biosynthesis of milk fats, and the challenges of replicating these features in non-mammalian systems. Emphasis is placed on short-chain fatty acids and chain-termination mechanisms in fatty acid synthesis. By integrating insights from diverse biological systems, we aim to contribute to a deeper understanding of the complex processes related to milk fat synthesis. Full article

Lactococcus lactis T-21 is a lactic acid bacterium isolated from wild cranberries in Japan that demonstrates significant immunomodulatory properties and has been incorporated into commercial health products. However, probiogenomic analyses specific to T-21 have remained largely unexplored. This study performed a thorough genomic characterisation of T-21 and evaluated its safety in initial clinical trials. Genomic analysis revealed substantial genetic diversity and metabolic capabilities, including enhanced fermentative potential demonstrated by its ability to metabolise a wide range of plant-derived carbohydrates, and genetic determinants associated with exopolysaccharide biosynthesis and nisin production, distinguishing T-21 from domesticated dairy strains. These attributes, reflective of its wild plant origin, may contribute to its metabolic versatility and unique probiotic functionalities. A preliminary clinical trial assessing the safety of T-21-fermented milk in healthy Japanese adults indicated no significant adverse outcomes, corroborating its safety for human consumption. Together, these findings support the feasibility of utilising non-dairy, wild plant-origin strains in dairy fermentation processes as probiotics. This study expands our understanding of the genomic basis for T-21’s probiotic potential and lays the groundwork for further investigations into its functional mechanisms and potential applications in promoting human health. Full article

Bioethanol is a renewable, environmentally-friendly biofuel conventionally produced through the alcoholic fermentation of sugary or starch-rich substrates by microorganisms, commonly Yeast Saccharomyces cerevisiae. Intermediates of industrial wheat flour wet milling processing to starch, such as A-starch and B-starch milk, are cost-effective, abundant, and non-seasonal feedstocks for bioethanol production. This study evaluates the bioethanol production from wheat A-starch and B-starch milk and mixtures of these two substrates in different ratios (1:3, 1:1, and 3:1) using two cold hydrolysis procedures at 65 °C: (i) simultaneous liquefaction and saccharification (SLS) followed by fermentation, and (ii) liquefaction by alpha-amylase followed by simultaneous saccharification and fermentation (SSF). The results demonstrated that SSF and SLS are equally efficient procedures for reaching a high ethanol yield of 53 g per 100 g of starch and 93% of starch conversion to ethanol for all investigated substrates. Lower levels of non-starch components in A-starch milk, which typically contribute to volatile by-product formation, allowed clear distillate profiles in terms of and lower content of aldehydes, methanol, and volatile acidity, enhancing ethanol distillate purity compared to B-starch milk. Mixing high-quality A-starch milk with low-cost B-starch milk enables higher ethanol yield, improved distillate quality, and energy savings for efficient industrial-scale applications. Full article

Encapsulation techniques play a crucial role in enhancing the stability and viability of probiotics in functional foods. This study investigates the efficacy of calcium–alginate encapsulation, combined with hydrocolloids such as carrageenan, agar, and gelatin, in improving the survival of Lactobacillus rhamnosus GG (LGG) and stabilizing the total phenolic content (TPC) in fermented black goji berry beverages. The results revealed that 1.5% alginate encapsulation, combined with 1% carrageenan, agar, or gelatin and 5% calcium, significantly enhanced the LGG viability and increased the TPC content in the fermented black goji berry beads when compared to calcium–alginate encapsulation alone. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the successful incorporation and interaction of hydrocolloids within the encapsulation matrix. Among the formulations, calcium–alginate–gelatin beads exhibited the highest LGG survival rates after simulated gastric and intestinal digestion. Notably, calcium–alginate beads containing carrageenan preserved LGG viability during simulated gastric and intestinal conditions when co-digested with all tested milk types (high carbohydrate, high protein, and high fat). Co-ingestion with these milk types further improved TPC retention in all bead formulations, as the macronutrients in milk provided protective effects, stabilizing the encapsulated polyphenols and minimizing their degradation during simulated gastric and intestinal digestion. This study highlights the potential of calcium–alginate encapsulation, integrated with hydrocolloids such as carrageenan, agar, or gelatin, to improve probiotic viability and polyphenol stability, offering promising applications for enhancing the functional properties of non-dairy fermented beverages. Full article

This study discusses the properties of mare milk as a potential food matrix to produce functional dairy products. The aim of this study was to investigate the effects of cold storage on the viability of microflora in fermented and unfermented mare’s milk, containing live monocultures of probiotic bacteria, during storage at low temperatures. Three fermented beverages were produced, differentiated by the bacterial flora used for production (Lactobacillus acidophilus LA-5 and Bifidobacterium animalis subsp. lactis BB-12), as well as one unfermented beverage (using 40% commercial kumis and 7% LA-5). The unfermented beverage was mare’s milk supplemented with a BB-12 monoculture, which was chilled immediately after adding the inoculum. The population of BB-12 remained above 6 log CFU/g until the 21st day of storage at 5 ± 1 °C, while for LA-5, it remained viable only up to 14 days of storage. The BB-12 population was high and stable for 21 days in both fermented and unfermented beverages. The results confirm the good quality of the final product (appropriate pH and high population of individual bacterial strains); not only are appropriate culture conditions important, but the use of suitable probiotic bacteria and the optimization of the starter concentrations should also be considered. There is considerable potential for further research and future commercialization of mare’s dairy products, such as yogurt and potentially other dairy products. Full article

Background: Cow’s milk represents an important protein source. Here, especially casein proteins are important components, which might be a promising source of alternative protein production by microbial expression systems. Nevertheless, caseins are difficult-to-produce proteins, making heterologous production challenging. However, the potential of genome-reduced Bacillus subtilis was applied for the recombinant production of bovine α_S1-casein protein. Methods: A plasmid-based gene expression system was established in B. subtilis allowing the production of his-tagged codon-optimized bovine α_S1-casein. Upscaling in a fed-batch bioreactor system for high cell-density fermentation processes allowed for efficient recombinant α_S1-casein production. After increasing the molecular abundance of the recombinant α_S1-casein protein using immobilized metal affinity chromatography, zeta potential and particle size distribution were determined in comparison to native bovine α_S1-casein. Results: Non-sporulating B. subtilis strain BMV9 and genome-reduced B. subtilis strain IIG-Bs-20-5-1 were applied for recombinant α_S1-casein production. Casein was detectable only in the insoluble protein fraction of the genome-reduced B. subtilis strain. Subsequent high cell-density fed-batch bioreactor cultivations using strain IIG-Bs-20-5-1 resulted in a volumetric casein titer of 56.9 mg/L and a yield of 1.6 mg_casein/g_CDW after reducing the B. subtilis protein content. Comparative analyses of zeta potential and particle size between pre-cleaned recombinant and native α_S1-casein showed pH-mediated differences in aggregation behavior. Conclusions: The study demonstrates the potential of B. subtilis for the recombinant production of bovine α_S1-casein and underlines the potential of genome reduction for the bioproduction of difficult-to-produce proteins. Full article

The majority of non-dairy starter cultures on the market are originally isolated from milk and therefore do not provide the most optimal fermentation for plant matrices. Developing plant-derived starter cultures is essential for creating high-quality, tasty dairy alternatives. This study aims to isolate and characterize bacterial strains with the potential to be used as non-dairy starters from plant sources via backslopping evolution. A natural consortium of macerated plants was inoculated into two oat and two pea commercial drinks and backslopped for seventeen cycles to evolve the bacterial consortium at 25 °C, 34 °C, and 42 °C. The results showed that the initial natural consortium contained less than 1% lactic acid bacteria, and after the seventeenth cycle, lactic acid bacteria dominated in all investigated consortia. Oat Od1-25 and Od2-42 and pea Pd1-34 and Pd1-42 samples were selected for strain isolation based on amplicon-based metagenetic analysis of 16S rRNA gene sequencing and sensory properties. The strain isolation was performed using an out-plating technique, and colonies were identified by MALDI-TOF mass spectrometry. Altogether, eleven lactic acid bacteria species of plant origin were obtained. The strains belonged to the Leuconostoc, Enterococcus, Lactobacillus, and Lactococcus genera. Full article

This study investigated the effects of three different single-strain probiotics Lactiplantibacillus plantarum XD117, Lacticaseibacillus paracasei LC-37, and Lacticaseibacillus rhamnosus LGG, on the quality of hempseed fermented milk. The main findings were that adding probiotics increased the inhibition rate of α-glucosidase and pancreatic lipase in hempseed fermented milk significantly. Non-targeted metabolomic correlation analysis results confirmed that 14 substances, including three flavonoids, six amino acids and their derivatives, and five short peptides, were positively correlated with the hypoglycemic and hypolipidemic activities of hempseed fermented milk. Furthermore, a total of 59 volatile flavor compounds were identified, including aldehydes, alcohols, ketones, acids, and esters, and the role mapping of different probiotic communities was provided. These results can guide the development of hempseed fermented milk with unique flavor, rich probiotic content, and significant functional characteristics. Full article

Labneh is a popular fermented dairy product, which contemporarily has diversified into a varied range of styles, formulated with the inclusion of multiple additives, and is sourced across the globe. This has driven labneh’s emergence as a complex product with varying textural and rheological characteristics. The lack of scientific literature about labneh products available in the United Arab Emirates (UAE) market and their characterization has prompted this study. A detailed UAE market analysis of labneh for label, formulation, nutrition, and price variability was conducted. Surveyed labneh products were categorized as unpackaged, multinational company (MNC), small and medium enterprise (SME), and specialty products. They differed in manufacturing, such as acid ± enzyme coagulation with/without post-fermentation heat treatment, and contained various stabilizers, emulsifiers, preservatives, and processing aids. Interestingly, almost equal proportions, 64.7% and 67%, of MNC and SME labneh contained additives, respectively. All MNC labneh were post-heat-treated, in contrast to only 7% of SME labneh. Organic labneh and non-bovine milk-based labneh are not yet widely available. The second part of the study involved the physicochemical characterization of a select number of packaged labneh that were categorized in accordance with fat content as high-fat (17–18%), full-fat (7.1–8%), and lite-fat (3.5–4.5%). High-fat labneh showed a significantly higher complex viscosity, complex modulus, hardness, adhesiveness, stringiness, and fracturability, followed by lite-fat labneh compared to full-fat labneh, especially when it contained pectin. Full-fat labneh with added gums (and starch) and high-fat labneh with gums showed a significantly lower complex modulus compared to their respective control labneh. This study highlights the variety of commercial labneh products available and differences in their formulation, manufacturing, and composition, and provides specific dependencies of materials with their physicochemical characteristics. Full article