Search Results (39)

Microbial detection in milk is crucial for food safety and quality, as beneficial and harmful microorganisms can affect consumer health and dairy product integrity. Identifying and quantifying these microorganisms helps prevent contamination and spoilage. The study employs advanced molecular techniques to detect and quantify the genomic DNA for the target hydrolytic enzyme coding genes lipA and aprX based on the multi-align sequence conserved region, specific primer pair, and hydrolysis probes designed using the singleplex qPCR and multiplex qPCR. Cultured isolates and artificially contaminated sterilized ultra-high-temperature (UHT) milk were analyzed for their specificity, cross-reactivity, and sensitivity. The finding indicated that strains with lipA and aprX genes were amplified while the other strains were not amplified. This indicated that the designed primer pairs/probes were very specific to the target gene of interest. The specificity of each design primer pair was checked using SYBR Green qPCR using 16 different isolate strains from the milk sample. The quantification specificity of each strain target gene was deemed to be with a mean Ct value for positive pseudomonas strain > 16.98 ± 1.76 (p < 0.0001), non-pseudomonas positive strain ≥ 27.47 ± 1.25 (p < 0.0001), no Ct for the negative control and molecular grade water. The sensitivity limit of detection (LOD) analyzed based on culture broth and milk sample was >10⁵ and >10⁴ in PCR amplification while it was >10⁴ and >10³ in real-time qPCR, respectively. At the same time, the correlation regression coefficient of the standard curve based on the pure culture cell DNA as the DNA concentration serially diluted (20 ng/µL to 0.0002 ng/µL) was obtained in multiplex without interference and cross-reactivity, yielding R² ≥ 0.9908 slope (−3.2591) and intercepting with a value of 37, where the efficiency reached the level of 95–102% sensitivity reached up to 0.0002 ng/µL concentration of DNA, and sensitivity of microbial load was up to 1.2 × 10² CFU/mL. Therefore, multiplex TaqMan qPCR simultaneous amplification was considered the best method developed for the detection of the lipA and aprX genes in a single tube. This will result in developing future simultaneous (three- to four-gene) detection of spoilage psychrotrophic bacteria in raw milk. Full article

The Hungarian Grey (HG) cattle breed was almost extinct after WW2; only 200 cows and six bulls survived. Despite the historical significance of the HG, no comprehensive genomic analysis has been conducted to clarify its genetic diversity and evolutionary history. Previous studies have relied on random or limited pedigree sampling, lacking a fully representative dataset determining genetic and conservation status. Here, the founder sampling of 110 individuals and the analysis of their mitochondrial DNA (mtDNA) sequence variation aim to investigate the phylogenetic placement of the breed using, for the first time, a fully representative sample. All identified haplogroups belong to the taurine T macro-haplogroup, with a predominance of T3 (89.1%), followed by T2 (4.5%), T1 (3.6%), and T1′2′3 (2.7%). The phylogenetic analysis confirms the absence of ancient haplogroups derived from European aurochs, suggesting a purely taurine origin for the HG breed. The high haplotype diversity (Hd = 0.94) and the genetic similarity to other Podolian breeds, particularly Maremmana cattle, indicate a preserved genetic background despite centuries of selective breeding. The lack of intensive crossbreeding practices has maintained the original beef production purpose of the breed, distinguishing it from the crossbred Podolian cattle used for dual-purpose or dairy production. Full article

Emotions evoked by food are an important factor that strongly influences the predictive power of consumer acceptance and consumption behavior when choosing food. The emotion questionnaire is an efficient measurement tool that describes the emotions evoked by different foods on the market. However, there is rarely a list of emotion terms for specific foods, such as the pure dairy products on the market. The aim of this study was to develop an emotion scale to measure emotion responses for pure dairy products and to investigate its application in consumer testing. A total of 1340 Chinese subjects (67% female, 18~45 years old, consumers of pure milk) participated in the study. The study began with the screening and identifying of emotion terms for pure dairy products and developed a proposed pure dairy product Emotion Scale (P-PDPES) with 50 emotion terms. Subsequently, the structure and emotion terms of the P-PDPES were determined using EFA and a final pure dairy product Emotion Scale (PDPES) with 33 emotion terms was obtained. The results showed that the PDPES has good validity and reliability. Moreover, the PDPES was used in a consumer test to describe the emotions towards the commercial pure dairy products. This PDPES discriminated well the emotions evoked by different pure dairy products and also indicated a good relationship between the model factors and the liking scores of milk products. To summarize, PDPES is a suitable measurement tool for assessing the emotions to pure dairy products. Full article

In order to obtain high-performing yeast strains from ruminants, it is necessary to select them from species such as beef cattle, dairy cows, goats, and buffalo. A total of 91 isolated yeasts were collected using the standard methods of microbial culture on agar medium followed by streaking on a plate at least three times until pure yeast colonies were formed. The API 20C AUX Kit and sequencing of the D1/D2 domain of the 26S rRNA gene were used to identify the genera Candida spp., namely, C. glabrata (99% identification), C. tropicallis (99%), C. rugosa (98%), and Issatchenkia orientalis (99%). A total of 12 yeast strains (Dc4, 14, 18; Be1, 2, 7; Bu3, 4, 7; and Go10, 16, 19) were chosen for further analyses. The performance criteria included the ability to tolerate pH values between 3.5 and 7.5, total volatile fatty acids (TVFAs, 0, 0.25, 0.5, 1, 2, and 4% of broth medium), anaerobic growth rate, and in vitro gas production efficiency. First, when all strains were grown at pH values between 3.5 and 7.5, Bu3 and Dc18 performed better than the other strains. Second, at a ruminal pH of 6.5 and a TVFA concentration of between 2 and 4% of the broth medium, strain Bu3 was more resistant than the other strains. Under anaerobic conditions, all strains experienced a decline in viable cell counts when compared with those under aerobic conditions. However, compared to strains Dc14, Be1, Be2, Be7, and Bu3, strain Dc18 exhibited more viable cells under anaerobic conditions in broth medium. The response of strain Dc18 did not differ from those of strains Dc4, Bu4, Bu7, or G16. Strains Be7, Bu3, and Dc18 were used for an in vitro fermentation experiment involving incubation for 2, 4, 6, 8, 10, 12, 24, 36, 48, and 72 h. Three ruminal cannulated dairy cows were used as donors of ruminal fluid. The treatments were run in triplicate. The addition of yeast culture had no effect on gas kinetics, gas accumulation, or the ratio of acetic acid and propionic acid, but led to significantly greater butyric acid concentrations at 24 h of incubation. In conclusion, strain Dc18 isolated from dairy cows is suitable for future studies of probiotic yeast development. Full article

Recent consumer demand for non-dairy alternatives has forced many manufacturers to turn their attention to cereal-based non-alcoholic fermented products. In contrast to fermented dairy products, there is no defined and standardized starter culture for manufacturing cereal-based products. Since spontaneous fermentation is rarely suitable for large-scale commercial production, it is not surprising that manufacturers have started to adopt centuries-known dairy starters based on lactic acid bacteria (LABs) for the fermentation of cereals. However, little is known about the fermentation processes of cereals with these starters. In this study, we combined various analytical tools in order to understand how the most common starter cultures of LABs affect the most common types of cereals during fermentation. Specifically, 3% suspensions of rice, oat, and wheat flour were fermented by the pure cultures of 16 LAB strains belonging to five LAB species—Lacticaseibacillus paracasei, Lactobacillus delbrueckii, Lactobacillus helveticus, Streptococcus thermophilus, and Lactococcus lactis. The fermentation process was described in terms of culture growth and changes in the pH, reducing sugars, starch, free proteins, and free phenolic compounds. The organoleptic and rheological features of the obtained fermented products were characterized, and their functional properties, such as their antioxidant capacity and angiotensin-converting enzyme inhibitory activity, were determined. Full article

Crops contamination with aflatoxins (AFs) and zearalenone (ZEA) threaten human and animal health; these mycotoxins are produced by several species of Aspergillus and Fusarium. The objective was to evaluate under field conditions the influence of the wet season on the dissemination of AF- and ZEA-producing fungi via houseflies collected from dairy farms. Ten dairy farms distributed in the semi-arid Central Mexican Plateau were selected. Flies were collected in wet and dry seasons at seven points on each farm using entomological traps. Fungi were isolated from fly carcasses via direct seeding with serial dilutions and wet chamber methods. The production of AFs and ZEA from pure isolates was quantified using indirect competitive ELISA. A total of 693 Aspergillus spp. and 1274 Fusarium spp. isolates were obtained, of which 58.6% produced AFs and 50.0% produced ZEA (491 ± 122; 2521 ± 1295 µg/kg). Houseflies and both fungal genera were invariably present, but compared to the dry season, there was a higher abundance of flies as well as AF- and ZEA-producing fungi in the wet season (p < 0.001; 45.3/231 flies/trap; 8.6/29.6% contaminated flies). These results suggest that rainy-weather conditions on dairy farms increase the spread of AF- and ZEA-producing Aspergillus spp. and Fusarium spp. through houseflies and the incorporation of their mycotoxins into the food chain. Full article

This study aimed to unleash the potential of indigenous lactic acid bacteria (LAB) originating from traditionally made Serbian goat cheese. Following the isolation and identification of the LAB, the safety aspects of the isolates were evaluated through tests for hemolytic activity and antibiotic sensitivity. The selected isolates were then tested for various technological properties, including growth in methylene blue, proteolytic activity, acidification, curd formation ability in both pure and enriched goat milk, diacetyl production, antagonistic potential against other LAB, and biofilm formation ability. The results indicated that Lactococcus spp., Lacticaseibacillus spp., and Lactiplantibacillus spp. did not exhibit α or β hemolysis, while enterococci displayed α hemolysis. A higher number of isolates demonstrated sensitivity to ampicillin, tetracycline, and streptomycin, while sensitivity to gentamicin and vancomycin was strain-dependent. Based on the evaluation of technological properties, Lacticaseibacillus paracasei M-1 and Lactiplantibacillus plantarum C7-7, C7-8, and C14-5 showed promising characteristics. Additionally, Lactococcus lactis subsp. lactis strains C0-14 and C21-8 emerged as promising candidates with notable technological properties. Notably, certain indigenous strains LAB exhibit promising technological properties and safety profiles. These characteristics make them suitable candidates for use as starter or adjunct cultures in goat’s milk cheese production, potentially enhancing the quality and safety of the cheese as well as hygiene practices among small-scale dairy producers. Full article

Fermentation of pumpkin puree and mature coconut water using water kefir grains is a potential method for producing a novel functional non-dairy-based probiotic drink. In the present study, response surface methodology based on Box–Behnken design (RSM-BBD) was used to optimise fermentation temperature and substrates’ concentrations. The optimised fermentation temperature, pumpkin puree, and brown sugar concentrations of pumpkin-based mature coconut water kefir beverage (PWKC) were 27 °C, 20%, and 10% w/v, respectively. The optimised PWKC (PWKC_opt) obtained an overall acceptability (OA) score of 4.03, with a desirable Lactobacillus count (6.41 Log CFU/mL), 0.68% v/v lactic acid content, 31% of water kefir grains’ biomass growth rate, and fermentation time (to reach pH 4.5) of 4.5 h. The optimized beverage, PWKC_opt, contained 3.26% proteins, 2.75% dietary fibre, 2186.33 mg/L of potassium, 180.67 mg/L phosphorus, and 137.33 mg/L calcium and had a total phenolic content of 89.93 mg GAE/100 mL, flavonoid content of 49.94 mg QE/100 mL, and carotenoid content of 33.24 mg/100 mL, with antioxidant activity (FRAP: 169.17 mM Fe(II)/100 mL, IC₅₀ value of DPPH free radicals scavenging activity: 27.17 mg/mL). Water kefir microorganisms in PWKC_opt remained stable for at least 56 days at 4 °C. Therefore, PWKC_opt might potentially serve as a value-added product, offering a basis for sustainable development within both the coconut and pumpkin industries. Full article

The dairy industry is actively seeking new applications for various types of whey. One promising direction is the development of nutritious ice cream, using a blend of different whey proteins. However, the production of whey ice cream is hindered by the occurrence of quality issues, primarily stemming from a low content of solids, particularly fat and protein. The development of natural components with distinctive technological attributes, such as the ability to bind excess moisture, enhance foaming properties, and replicate the taste of milk fat, is of significant relevance in food science. In this work, we investigated the influence of plant-based structuring ingredients on the viscoelastic characteristics of whey-based ice creams. Notably, mixes such as 0.4% Vianoks C45 + 0.75% oat β-glucan, 0.4% Vianoks C45 + 0.5% yeast β-glucan, and 0.4% Vianoks C45 + 3% whey protein complex + 10% vegetable purée from table beet have been proven to be effective stabilizing compositions. However, attempts to combine the whey protein complex with other types of vegetable purées like zucchini and broccoli did not yield satisfactory results. It has also been found that β-glucan from the yeast Saccharomyces cerevisiae and κ-carrageenan, a component of the Vianoks C45 stabilization system, forms a robust gel within the system. Analysis of the aqueous phase in whey-based ice creams revealed a consistent correlation between water activity, surface tension, and rheological behavior. Finally, the ice creams that exhibited the best viscoelastic characteristics also had the best sensory attributes. Full article

This manuscript aims to report the clinical and laboratory diagnosis of puerperal metritis (PM) in a dairy cow, caused by H. somni as a unique pathogen. The cow showed signs of systemic illness, including a sudden drop in milk production, a rectal temperature of 40.4 °C, tachypnea, dehydration, and completely fluid, brown, and fetid uterine discharge. Pure cultures of H. somni were identified and submitted to the Kirby–Bauer disc diffusion method for antibiotic sensitivity. The study showed that H. somni was resistant to tetracyclines and cephalosporins (Ceftiofur), antibiotics commonly used to treat uterine infections in dairy cows. To the authors’ knowledge, this case describes for the first time PM caused by H. somni as a primary pathogen. Our results should lead to the inclusion of H. somni as a primary pathogen of metritis in laboratory diagnoses on a routine basis, which, in turn, may help to elucidate the incidence of H. somni as a causative agent of uterine infections in cows. If the incidence of H. somni is remarkably high or frequent, researchers could consider the use of commercial vaccines nowadays destined for the prevention of bovine respiratory disease and which could perhaps be effective in the prevention of reproductive pathology caused by H. somni. Full article

Fermented dairy products not only have a long shelf-life but also have beneficial nutritional values. The products are deficient in dietary fiber and certain bioactive compounds. Adding grains to dairy products is a widespread practice to improve the nutritional and economic aspects. In this work, we studied the effect of fermented millet–milk beverages (FMBs) using pearl millet grains and three different dairy by-products (sweet whey, sweet buttermilk, and skimmed milk). A control treatment prepared with water was also manufactured for comparison. Samples were continuously prepared and fermented using a commercial yogurt starter culture (YC-381) containing L. delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and a pure strain of L. paracasei subsp. Paracasei. Four FMBs (water based: WB-FMB, whey based: WHB-FMB, buttermilk based: BMB-FMB, and skimmed milk based: SMB-FMB) were analyzed during cold storage at 4 °C for up to 15 days for chemical, microbiological properties, minerals content, antioxidant properties, glycemic index, and glycemic load on days 1, 8, and 15. The sensory characteristics of the FMBs were also evaluated during cold storage (4 °C/15 days). In general, the progression of acidity was slower in SMB-FMB and WHB-FMB samples during fermentation compared to in the BMB-FMB sample. The longest fermentation time was for the SMB-FBM sample (3 h), while the shortest was for the BMB-FMB sample (1.5 h). Reflecting the good manufacturing practices, all samples were free of coliform, mold, and yeast. No bacterial growth was detected in the WB-FMB sample at days 8 and 15 of storage, while the growth of Lactobacillus spp. and S. thermophilus was significantly higher (9.97 ± 0.01 and 9.48 ± 0.06, respectively) in the BMB-FMB sample compared to in the other three FMBs. The FMBs produced using dairy by-products had more antioxidant properties. All samples were better perceived during sensory evaluation by panelists than the water-based sample, except for the BMB-FMB sample, in which a bitter taste appeared. In the BMB-FMB sample, the proteolytic degree was significantly higher (4.8 ± 0.09) after 3 h of fermentation by about 460% than in the fresh sample. All samples had a low glycemic index and glycemic load. In addition, acidity progression was slower in SMB-FMB and WHB-FMB samples during fermentation and storage compared to the WB-FMB sample. Therefore, it could be recommended that it is more beneficial to prepare fermented millet–milk beverages using dairy by-products and suitable starter cultures under optimal fermentation conditions instead of using water to maximize the nutritional and economic aspects. Full article

The necessity of reducing the greenhouse effect by decreasing the carbon dioxide fingerprint directed the food packaging technology to use biobased raw materials. Alginates, which are derived from brown algae species, are one of the most promising biobased biopolymers for the development of edible active coatings capable of protecting food from oxidation/bacterial spoilage. In this study, sodium alginate, which was plasticized with glycerol and mixed with a biobased thymol/natural halloysite nanohybrid, was used to develop novel edible active coatings. Nanocomposite coatings were also developed in this project by mixing pure halloysite with sodium alginate/glycerol matrix and were used as reference material for comparison reasons. Instrumental analysis indicated a higher compatibility of a thymol/halloysite nanohybrid with a sodium alginate/glycerol matrix compared to pure halloysite with a sodium alginate/glycerol matrix. Increased compatibility resulted in improved tensile properties, water/oxygen barrier properties, and total antioxidant activity. These edible active coatings were applied to traditional Greek spread cheese and showed a reduction in the mesophilic microbial population over one log10 unit (cfu/g) compared to uncoated cheese. Moreover, the reduction in the mesophilic microbial population increased with the increase in halloysite and thymol content, indicating such sodium alginate/glycerol/thymol/halloysite hydrogels as promising edible active coatings for dairy products. Full article

The flavor of fresh, raw milk is considered to be the key to maintaining the quality of dairy products, and is very crucial in affecting a consumer’s choice. To better understand the differences in flavor of fresh milk between feeding patterns, we conducted the following study. Twelve Holstein cows reared in pure grazing mode and twelve reared intensively in medium to large farms were selected from the Xinjiang Uygur Autonomous Regions at the same time, and the flavor of their raw milk was analyzed. Aroma profiles and taste attributes were assessed by electronic nose and electronic tongue, respectively, and volatile flavor compounds were characterized and quantified by Headspace-Solid Phase Microextraction/Gas Chromatography-Mass Spectrometry. Thirteen volatile compounds were identified in the indoor feeding pattern and 12 in the grazing; most of them overlapped. W1S, W2S and W5S were the main contributing sensors of the electronic nose for the overall assessment of the aroma profile. Raw milk from grazing had more intense astringency, bitterness, sourness and richness in taste compared to indoor feeding. Different dietary conditions may contribute to a variety of aroma profiles. Oxime-, methoxy-phenyl-, octadecanoic acid, furfural and dodecanoic acid were the key volatile flavor compounds of grazing. Meanwhile, raw milk from indoor feeding patterns was unique in 2-nonanone, heptanoic acid and n-decanoic acid. All three detection techniques were valid and feasible for differentiating raw milk in both feeding patterns, and the compounds were significantly correlated with the key sensors by correlation analysis. This study is promising for the future use of metabolic sources of volatile organic compounds to track and monitor animal feeding systems. Full article

Human norovirus and hepatitis viruses (hepatitis A (HAV) and hepatitis E (HEV)) are leading causes of foodborne disease worldwide. Among the various food products, different types of dairy products can be implicated in viral foodborne outbreaks and contamination can occur at different stages, such as preparation, contact with contaminated equipment or via other foods. The aim of this study was to characterise a proteinase K method adapted from the ISO 15216 method for the detection of HAV, HEV and norovirus in artificially contaminated dairy products, based on the recent international standard of ISO 16140-4. Results showed that the recovery yields obtained from pure RNA in dairy products ranged from 5.76% to 76.40% for HAV, from 35.09% to 100.00% for HEV, from 25.09% to 100.00% for norovirus GI and from 47.83% to 100.00% for norovirus GII. The process control MNV-1 was detected in all RNA extracts, with recovery yields between 36.83% and 100.00%. The limit of detection (LOD) of the method was between 184 and 642 genome copies/mL (or/g) for the LOD₅₀ and 802 and 2800 genome copies/mL or/g for the LOD₉₅ according to the virus analysed. This method proved to be suitable for detecting viruses in dairy products for routine diagnostic needs. Full article

The microencapsulated mixture of organic acids and pure botanicals (OA/PB) has never been evaluated in goats. The aim of this study was to extend the analysis to mid–late lactating dairy goats, evaluating the effects of OA/PB supplementation on the metabolic status, milk bacteriological and composition characteristics, and milk yield. Eighty mid–late lactating Saanen goats were randomly assigned to two groups: one group was fed the basal total balanced ration (TMR) (CRT; n = 40) and the other was fed a diet that was TMR supplemented with 10 g/head of OA/PB (TRT; n = 40) for 54 days during the summer period. The temperature–humidity index (THI) was recorded hourly. On days T0, T27, and T54, the milk yield was recorded, and blood and milk samples were collected during the morning milking. A linear mixed model was used, considering the fixed effects: diet, time, and their interaction. The THI data (mean ± SD: 73.5 ± 3.83) show that the goats did not endure heat stress. The blood parameters fell within the normal range, confirming that their metabolic status was not negatively influenced by OA/PB supplementation. OA/PB increased the milk fat content (p = 0.04) and milk coagulation index (p = 0.03), which are effects that are looked on as favorable by the dairy industry in relation to cheese production. Full article