Traditional Dairy Products Research Articles

Supplementation of tomato pomace in lassi (a traditional Indian dairy product)and its effects on physico-chemical, functional attributes and shelf-life of lassi

Utilization of agriculture waste as food additives increased significantly due to their potential health and nutritional attributes. Tomato crop is widely grown across the globe and generates large amount of waste in the form of tomato pomace during the processing of tomato. Dried tomato pomace has a higher shelf-life and easier for food fortification. Lassi is a traditional Indian dairy product consumed as a refreshing beverage during summer. Considering the various health and nutritional benefits of tomato pomace present study was undertaken to supplement tomato pomace in lassi. Tomato pomace powder (TPP) was prepared by tray drying at 55-60 °C for 16-18hrs. Pomace had 16.70% protein, 57.53% crude fibre, and 49.80%2, 2 diphenyl-1-picryl hydroxyl (DPPH) inhibition activity, 311.7mg gallic acid equivalents (GAE)/100g total phenolic content(TPC). Supplementation of tomato pomace was done at different rates of 0.5, 1.0, 1.5, and 2.0% (w/v) of milk during the heating of milk. 1% tomato pomace added lassi had a better sensory score and physico-chemical properties with an overall acceptability score of 7.5. In, addition 1 % tomato pomace lassi had 2.53% fat,2.67% protein, 18.81% total solids, 0.66% ash, 21.81% DPPH inhibition antioxidant activity and 12.37 mg GAE/100 g. Tomato pomace powder added lassi was found stable up to 12 days of storage study while the control sample (without tomato pomace)was unacceptable after 9 days of storage. Lassi supplemented with tomato pomace rich in fibre and antioxidant activity. Utilization of tomato pomace in lassi fortification can be better alternative for tomato processor as lassi consumed very large segment of population.

Exploring the Probiotic Potential and Safety of a Locally Sourced Lactobacillus fermentum Strain Isolated from Dahi, a Traditional Dairy Product

Exploring the Probiotic Potential and Safety of a Locally Sourced Lactobacillus fermentum Strain Isolated from Dahi, a Traditional Dairy Product

Vegan alternative for fermented milk products: Preparation and some properties

Rice is relatively easy to digest by humans, and the presence of starch provides the organism with slow energy. In addition, the absence of lactose makes it possible to provide a complete diet for people suffering from allergies or individual intolerance to cow’s milk components. Therefore, the creation of analogues to traditional dairy and fermented milk products is a timely and in-demand task. The use of biotechnology methods allows not only to obtain a product with original organoleptic characteristics, but also to enrich it with metabolites of lactic acid bacteria, to give pre- and probiotic properties. The issues of obtaining fermented rice base (FRB) as a basis for alternative vegan products have been studied. It is shown that with the ratio of solid and liquid phases in the rice base – 1:2, respectively, favourable conditions were created for the development of lactic acid bacteria. It was found that additional treatment (partial enzymatic hydrolysis at a temperature of 40 ± 2 °C for 60 minutes) mixtures before fermentation improves the adaptation of the microbiota to this substrate. In addition, the taste of the rice base improves: a pronounced sweetness appears, the flour flavour disappears, the consistency becomes more viscous. The process of fermentation (for 12 hours at a temperature of 38-40 °C) of rice base was studied, the dynamics of acid accumulation depending on the introduced cultures of lactic acid bacteria was studied. The expediency of applying pectin (1% and 2% by weight) is shown to regulate the consistency of the FRB. The FRB samples received a high sensory evaluation.

Plant-based dairy substitutes: Current scenario and future prospects

Plant-based dairy substitutes (PBDS) are non-dairy products made from plant ingredients as an alternative to traditional dairy products such as milk, cheese, and yoghurt. These dairy substitutes cater to those with lactose intolerance, dairy allergies, vegans, and those who prefer more sustainable and ethical food options. They provide options for various culinary purposes while reducing reliance on animal-based products. PBDS generally have a low environmental footprint, requiring fewer resources and lower greenhouse gas emissions than dairy farming. Some PBDS are enriched with vitamins and minerals, such as vitamin D and calcium, providing similar nutritional benefits to dairy products. They have advantages over conventional dairy products due to their low glycemic content and hence have better suitability for diabetic patients. Moreover, people with heart ailments or arthritis can also consume PBDS for its hypocholesterolemic and anti-inflammatory properties. They also help in befitting pregnant women, foetus, lactating mothers, infants and elderly people. As plant-based dairy substitutes offer many benefits, selecting products that suit an individual\'s dietary needs and preferences ensures sufficient intake of essential nutrients. Ongoing research and development in the plant-based industry has improved taste and texture, making these substitutes increasingly attractive for routine human consumption.

The heated-induced gelation of soy protein isolate at subunit level: Exploring the impacts of α and α′ subunits on SPI gelation based on natural hybrid breeding varieties

Soy protein isolate (SPI) is widely used in the food industry as a gelling agent due to its high water-holding capacity and gelation. As a key in elucidating the structure-function relationships of SPI, subunit composition can explain many functional properties of soy protein. In this study, to explore the influence of α and α′ subunits on the gel properties of soy protein, the gel strength and water holding capacity of the heat-induced gel with missing subunits were determined. Texture Profile Analysis (TPA) showed that gel strength from large to small was α′-lack > (α and α′)-lack > native > α-lack, and the lack of α′ subunit significantly enhanced ( p < 0.05) the gel strength and water-holding capacity of the resultant gels. In the gel formation process, microstructure observation of the gels revealed that the α′-lacking gel had a more uniform and denser network structure with higher storage modulus, promoting more water molecules to be bound in the gel structure as immobilized water and exhibiting higher thermal stability. Subsequently, the lack of α′ subunit increased the zeta potential, surface hydrophobicity (H 0 ), and fluorescence intensity of the gel. The deletion of the α′ subunit promoted the exposure of hydrophobic groups with more hydrophobic amino acids and promoted the aggregation of the subunits after heat treatment. These changes in the physicochemical properties of the gel affected their heat-induced gelation. In addition, gel solubility results signify that hydrophobic and disulfide bond interactions are the main forces in the gel formation process. Thus, the deletion of the α′ subunit will facilitate the development and application of soy protein products in food processing and improve their gel properties. This study will benefit the application of soy protein at the subunit level in traditional dairy products based on heated-induced gelation. • Soy proteins with α or α′ subunit deficiency showed different gelling properties. • The α′-lack significantly improved the gel strength, water holding capacity. • Gel network prepared from α′-lacking SPI had the densest structure. • α′ subunit-deficient soy protein might be a good candidate for gel production in the food industry.

Extraction and characterization of essential oil of nutmeg (Myristica fragrans) fruit pericarp and utilization as a surface coating material to improve the shelf life of paneer

Paneer is a traditional dairy product of India and is similar to unripened soft cheese. It is used as a raw material for the preparation of a variety of culinary dishes and snacks. Paneer is marble white in appearance, with a firm, cohesive and spongy body and a sweetish-acidic-nutty flavor. But it is highly perishable with a limited shelf- life like other indigenous dairy products. Its shelf life was reported to be only six days under refrigeration, though its freshness is lost within three days. The spoilage of paneer occurs mainly due to the growth of microorganisms, which bring about various physico-chemical changes. In the present study, attempts were made to increase the shelf-life of paneer at refrigerated storage by the application ofnutmeg pericarp essential oil surface coating. The essential oil was prepared from fresh nutmeg fruit flesh by steam distillation method. The physico-chemical and bio functional properties of essential oil were determined. The specific gravity and refractive index of the essential oil were found to be 0.903 and 1.477 respectively. The acid value and total polyphenolic value of essential oil were 3.36 and 4.04 mg GAE/g respectively. The essential oil was also found to have good antimicrobial and antioxidant activity. The shelf life of samples coated with essential oil packaged in LDPE pouches had more shelf life than the control paneer, as the coated paneer kept well for 9 days while the control paneer spoiled after the 6th day of refrigerated storage. The paneer with essential oil coating obtained satisfactory sensory scores.

Microbiological Biodiversity of Regional Cow, Goat and Ewe Milk Cheeses Produced in Poland and Antibiotic Resistance of Lactic Acid Bacteria Isolated from Them.

(1) Unique sensory values of traditional and regional dairy products made them more and more popular among consumers. Lactic acid bacteria naturally occurring in these products can express antibiotic resistance and be a reservoir of antibiotic resistance genes (ARG) in the environment. The aim of the study was to characterize the microbial diversity of twenty regional cheeses produced from non-pasteurized cow, goat and ewe milk, and investigate the phenotypic and genotypic antibiotic resistance (AR) of lactic acid bacteria isolated from these products. (2) Conventional microbiological methods were applied for the enumeration of lactic acid bacteria (lactobacilli and lactococci) and their isolation, and for the enumeration of Enterococcus, Staphylococcus, Enterobacteriaceae and spores. The disc diffusion method was applied for phenotypic AR. The PCR-based methods were used for strain identification, microbiological diversity of cheeses (PCR-DGGE), and for AR gene detection. (3) Among 79 LAB isolates the most frequent species were L. plantarum (n = 18), Leuc. lactis (n = 17), Lc. lactis (n = 11), Leuc. mesenteroides (n = 9) and L. pentosus (n = 8). Additionally, by using the PCR-DGGE method, DNA of L. casei was found in nine products. Lactobacilli (5.63-8.46 log cfu/g) and lactococci (6.15-8.41 log cfu/g) predominated over Enterococcus (max. 4.89 log cfu/g), Staphylococcus (max. 4.18 log cfu/g), and Enterobacteriaceae (mostly up to 4.88 log cfu/g). Analysis of phenotypic resistance to tetracycline (30 µg), erythromycin (15 µg), and chloramphenicol (30 µg) showed that 29% of LAB isolates were resistant to one antibiotic, 8%-to two, and 12%-to all tested antibiotics. Antibiotic resistance genes (AGR) for tetracycline (tet(M), tet(L), tet(W)), erythromycin (erm(B)) and chloramphenicol (cat-TC) were detected in 30 (38%), 29 (36.7%) and 33 (43.4%) LAB isolates, respectively. Among 31 LAB isolates phenotypically susceptible to all tested antibiotics, only 5 (16%) had no ARGs. (4) The results obtained in our work shed light on the potential threat posed by the widespread presence of ARGs in LAB present in regional cheeses.

The occurrence of antibiotic-resistant enteric bacteria in Selected Nigerian traditional dairy products.

Wara and nono are popular dairy products in Nigeria, rich in nutrients, highly exposed to microbial contaminants during processing and sale and support microbial growth. To investigate occurrence and antibiotic resistance pattern of enteric bacterial pathogens in dairy products. Dairy products were serially diluted and cultured on Eosin Methylene Blue agar, Salmonella-Shigella agar, McConkey agar and nutrient agar at 37°C for 24 h. Characterisation and identification of isolates with API 20E kit (Biomereux, France). Antibiotic susceptibility was with agar disc diffusion. Polyvalent O and H antisera for Salmonella serotyping. Salmonella enterica serovar Enteritidis, Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Typhi, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae and Serratia marcescens, were identified. Dominant enteric bacterium detected was E. coli followed by Salmonella spp. Serratia marcescens was the least occurring. The isolates were most resistant to trimethoprim-sulfamethoxazole (96.7%), amoxicillin (83.3%), augmentin (83.3%), chloramphenicol (66.7%), streptomycin (50%). They were resistant to ≥ 4 (multiple) antibiotics, E. coli 8, Salmonella spp. 7, Serratia marcescens 6 and Klebsiella spp. and Enterobacter spp. 4 each. The presence of enteric bacterial pathogens in wara and nono and their resistance to multiple antibiotics was reported in this study.

Microbial communities and main features of labneh Ambaris, a traditional Lebanese fermented goat milk product

Labneh Ambaris is a traditional Lebanese dairy product typically made using goat milk in special earthenware jars. Its production is characterized by the regular additions of milk and coarse salt, all while draining the whey throughout a process that lasts for a minimum of 2 mo. In this study, 20 samples of labneh Ambaris, all produced by spontaneous fermentation, were studied. They were collected at the end of fermentation from different regions in Lebanon. Physicochemical and sensory properties were studied and microbial diversity was analyzed using culture-dependent and independent techniques. The V3-V4 region of the 16S rRNA gene and the ITS2 region were sequenced by DNA metabarcoding analyses for the identification of bacteria and yeast communities, respectively. Out of 160 bacterial and 36 fungal taxa, 117 different bacterial species and 24 fungal species were identified among all labneh Ambaris samples studied. The remaining ones were multi-affiliated and could not be identified at the species level. Lactobacillus was the dominant bacterial genus, followed by Lentilactobacillus, Lactiplantibacillus, Lacticaseibacillus, and Lactococcus genera, whereas Geotrichum and Pichia were the dominant fungal genera. The 20 samples tested had varying levels of salt, protein, and fat contents, but they were all highly acidic (mostly having a pH < 4). According to the sensory scores generated by classical descriptive analysis, all samples were described as having basic similar characteristics such as goat smell and flavor, but they could be differentiated based on various intensities within the same descriptors like salty and acidic. This work could be considered as a base toward obtaining a quality label for labneh Ambaris.

Traditional Fermented Dairy Products in Southern Mediterranean Countries: From Tradition to Innovation

Fermented dairy products have been essential elements in the diet of Southern Mediterranean countries for centuries. This review aims to provide an overview of the traditional fermented products in Southern Mediterranean countries, with a focus on fermented dairy products, and to discuss innovative strategies to make improved versions of these traditional products. A large variety of fermented dairy products were reviewed, showing high diversity, depending on the used raw materials, starter cultures, and preparation procedures. Traditionally, dairy products were fermented using spontaneous fermentation, back-slopping, and/or the addition of rennet. Compared with commercial products, traditional products are characterized by peculiar organoleptic features owing to the indigenous microflora. The main limitation of traditional products is preservation as most products were consumed fresh. In addition to drying, brine or oil was used to extend the product shelf life but resulted in high salt/fat products. Several studies suggested alternative ingredients/processing to make revised products with new flavors, improved nutritional quality, and a longer shelf life. There is still plenty of room for more research to obtain a better understanding of the indigenous microflora and on quality improvement and standardization to reach a wider market.

Microbial diversity of milk ghee in southern Gansu and its effect on the formation of ghee flavor compounds.

Ghee is a traditional Tibetan dairy product with high-fat content, low yield, plasticity, caseation, and rich nutrition. In this study, we analyzed the diversity of microbial communities in yak milk and ghee samples at high and low altitudes, especially the Lactobacillus genus, and further used metabolomic techniques to compare the differences in metabolites in yak ghee at different altitudes. The results showed that the increase in altitude had a significant and generally inhibitory effect on the microbial community diversity in milk ghee, and yak milk at high altitude was abundant in nutrients, which could antagonize the negative impact of increased altitude. Using non-targeted metabolomics, we infer the composition of flavor compounds in ghee: nine kinds of carboxylic acids, 11 kinds of esters, six kinds of ketones, two kinds of alcohols, and four kinds of alkene compounds, among which the key flavor compounds are dl-2-(acetylamino)-3-phenylephrine acid, 1-(4-methoxyphenyl)-2-propanone, sebacic acid, Lysope 18:1, and uracil 1-beta-d-arabinofuranoside. These flavor substances are found in Lactococcus, Lactobacillus, and Streptococcus. With the participation of Lactobacillus, it is synthesized through biosynthesis of alkaloids derived from ornithine, lysine, and nicotine acid and glyoxylate and decarboxylate metabolism, among which Lactococcus plays a key role. In this study, a variety of lactic acid bacteria related to ghee fermentation were screened out, revealing the composition of volatile flavor compounds in Gannan yak milk ghee in the Qinghai-Tibet Plateau and providing a reference for further key volatile flavor compounds and the formation mechanism of flavor compounds.

Graduate Student Literature Review: Labeling challenges of plant-based dairy-like products for consumers and dairy manufacturers

The global market for plant-based products is increasing at a faster rate than the market for traditional dairy products. Current regulations provide standards for those traditional dairy products but lack the same regulations for similar plant-based products. Resulting from this difference in regulation is consumer confusion over the differences between the 2 types of products. The purpose of this review paper was to understand how the differences between traditional dairy and plant-based dairy-like products could affect litigation by consumer and dairy manufacturers against potential misleading labeling. A review of the available literature found 4 relevant articles for analysis. Consumers and manufacturers can pursue claims against potentially misleading product labeling but must provide sufficient evidence to prove deception or injury. Past litigation against plant-based products for being misleading has ruled in favor of the plant-based defendants. These rulings were based on the notion that reasonable consumers would not be misled. Consumer and manufacturing advocates for dairy products should focus more resources on the education of consumers rather than litigation if the goal is to promote dairy products. Long-term regulatory changes could be made through the Defending Against Imitations and Replacements of Yogurt, Milk, and Cheese to Promote Regular Intake of Dairy Everyday Act, which is currently under legislative review.

Artisanal Household Milk Pasteurization Is Not a Determining Factor in Structuring the Microbial Communities of Labneh Ambaris: A Pilot Study.

Labneh Ambaris is a traditional Lebanese dairy product traditionally made using raw goat's milk in earthenware jars, but recently the use of artisanally pasteurized milk was introduced for safety reasons. In this study, 12 samples of labneh Ambaris were studied, six made using raw goat's milk and six others using artisanally pasteurized goat's milk. These samples were collected during fermentation and their microbial compositions were analyzed. The 16S V3-V4 and the ITS2 regions of the rDNA were sequenced by DNA metabarcoding analyses for the identification and comparison of bacterial and fungal communities, respectively. The samples had high microbial diversity but differences in samples microbiota were unrelated to whether or not milk was pasteurized. The samples were consequently clustered on the basis of their dominant bacterial or fungal species, regardless of the milk used. Concerning bacterial communities, samples were clustered into 3 groups, one with a higher abundance of Lactobacillus helveticus, another with Lactobacillus kefiranofaciens as the dominant bacterial species, and the third with Lentilactobacillus sp. as the most abundant species. Species belonging to the Enterobacteriaceae family were detected in higher abundance in all raw milk samples than in artisanally pasteurized milk samples. As for fungal communities, the samples were clustered into two groups, one dominated by Geotrichum candidum and the other by Pichia kudriavzevii.

Production of kurut (kurt) using probiotic Lacticaseibacillus rhamnosus GG strain in combination with a yeast isolated from Kazakhstan kurut

Kuruts are traditional acid-coagulated fermented dairy products in semisolid or dried form. The present study used probiotic Lacticaseibacillus rhamnosus GG (LGG) and Cryptococcus laurentii yeast, a kurut isolate, to make mixed-fermentation kurut. In addition, kurut was fermented with L. rhamnosus GG as starter. Kurut was also fermented with kefir grains representing a traditional way to initiate the fermentation. The viability of probiotic L. rhamnosus GG strain and physicochemical properties of semisolid kurut products were monitored during storage over 22 days at 4°C. The tested probiotic strain showed viability higher than 7 log CFU/mL in both mixed-fermentation and single-strain-fermentation kurut during storage at 4°C. When prepared with probiotic bacteria, the syneresis values of mixed-fermentation kurut were lower (p &amp;gt; 0.05) than single-strain-fermentation kurut. The flavor and overall acceptability scores for kurut prepared using the combination of probiotic LGG and C. laurentii yeast as starter culture were higher than for the other samples at 11 days of storage (p &amp;gt; 0.05). Taking the above into consideration, probiotic kuruts obtained by milk fermentation inoculated with co-culture of L. rhamnosus GG and C. laurentii yeast could be potential probiotic products to be produced in the dairy industry.

FDF-DB: A Database of Traditional Fermented Dairy Foods and Their Associated Microbiota.

Fermented foods are attracting increasing interest due to their nutritional and health benefits, including a positive impact on gut microbiota exerted by their associated microbes. However, information relative to traditional fermented dairy products, along with their autochthonous microbiota, is still fragmented and poorly standardized. Therefore, our aim was to collect and aggregate data useful for obtaining a comprehensive overview translated in a classical database interface that can be easily handled by users. a preliminary inventory was built up by systematically collecting data from publicly available resources for the creation of a list of traditional dairy foods produced worldwide, including additional metadata useful for stratifying, and collapsing subgroups. we developed the Fermented Dairy Food Database (FDF-DB), a feasible resource comprising 1852 traditional dairy foods (cheeses, fermented milks, and yogurt) for which microbial content and other associated metadata such as geographical indication label, country/region of origin, technological aspects were gathered. FDF-DB is a useful and user-friendly resource where taxonomic information and processing production details converge. This resource will be of great aid for researchers, food industries, stakeholders and any user interested in the identification of technological and microbiological features characterizing traditional fermented dairy products.

Microbial Communities in Home-Made and Commercial Kefir and Their Hypoglycemic Properties

Kefir is a popular traditional fermented dairy product in many countries. It has a complex and symbiotic culture made up of species of the genera Leuconostoc, Lactococcus, and Acetobacter, as well as Lactobacilluskefiranofaciens and Lentilactobacillus kefiri. Though kefir has been commercialized in some countries, people are still traditionally preparing kefir at the household level. Kefir is known to have many nutritious values, where its consistent microbiota has been identified as the main valuable components of the product. Type 2 diabetes mellitus (T2DM) is a common diet-related disease and has been one of the main concerns in the world’s growing population. Kefir has been shown to have promising activities in T2DM, mostly via hypoglycemic properties. This review aims to explain the microbial composition of commercial and home-made kefir and its possible effects on T2DM. Some studies on animal models and human clinical trials have been reviewed to validate the hypoglycemic properties of kefir. Based on animal and human studies, it has been shown that consumption of kefir reduces blood glucose, improves insulin signaling, controls oxidative stress, and decreases progression of diabetic nephropathy. Moreover, probiotic bacteria such as lactic-acid bacteria and Bifidobacterium spp. and their end-metabolites in turn directly or indirectly help in controlling many gut disorders, which are also the main biomarkers in the T2DM condition and its possible treatment.

Screening of lactic acid bacteria strains with urate-lowering effect from fermented dairy products.

Hyperuricemia is a well-known cause of gout and also a risk factor for various comorbidities. Current agents like xanthine oxidase inhibitors prevent hyperuricemia, but usually induce severe side effects. Alternative strategies, such as novel dietary supplementations, are necessary for the management of hyperuricemia. Lactic acid bacteria (LAB) have been used in human diet for a long time with a good safety record. In this study, 345 LAB strains isolated from traditional fermented dairy products were tested for assimilating abilities of guanosine. Two LAB strains, Lacticaseibacillus rhamnosus 1155 (LR1155) and Limosilactobacillus fermentum 2644 (LF2644), showing great capacities of guanosine transformation and degradation were selected. Compared to LR1155, LF2644 showed a better effect with 100.00% transforming rate and 55.10% degrading rate. In an in vivo test, a hyperuricemic rat model was established and the results showed that administration of LR1155 (p<0.01) or LF2644 (p<0.01) prevented the rise of serum uric acid with more than 20% decrease when compared with the hyperuricemia rats. In addition, an increased fecal uric acid level was observed in LF2644 or LR1155 treated rats (LR1155-M p<0.05, others p<0.01). This study proved that LR1155 and LF2644 can be promising candidates of dietary supplements for prevention or improvement of hyperuricemia. PRACTICAL APPLICATION: The LAB strains tested in this study could be considered as good potential probiotic candidates for dietary supplements because of their urate-lowering effects, which provide a novel antihyperuricemic strategy with advantages of safety and sustainability.

Whole-Genome Sequencing and Comparative Genomic Analysis of Enterococcus spp. Isolated from Dairy Products: Genomic Diversity, Functional Characteristics, and Pathogenic Potential

Enterococci are commensal organisms that have probiotic effects for their hosts and can be used as adjunct cultures in fermented dairy products. The dark side of Enterococci is manifested in E. faecium and E. faecalis, which are the causative agents of nosocomial infections, and thus Enterococci have not been granted a safety status as food additives. In this context, we aimed to assess the safety and functional profile of an Enterococci collection retrieved from traditional dairy products through a high-resolution genomic characterization and comparative genomic analysis. Analysis did not reveal major differences in the main cellular processes of Enterococci. Moreover, a diverse repertoire of resistance and virulence genes was present, though known hallmark pathogenicity factors were either absent or occurred rarely. The abundance of bacteriocins and CRISPR/Cas systems suggested the ability of the isolates to suppress pathogens and evade bacteriophages, respectively. Presence–absence patterns of genes suggested that dairy-originated E. faecium are not associated with pathogenicity factors, while those of human origin are strongly linked with notorious resistance and virulence determinants. Our comparative analysis provided some notable insights regarding the genomic composition of Enterococci in the context of their origin. However, their pathogenic lifestyle is likely to be explained by the interplay of multiple genomic factors.

Development and validation of a multi-residue method for determination of antimicrobial sulfonamides, macrolides and quinolones in Iranian feta cheese by SPE clean-up and LC-MS/MS

A selective and sensitive multi-residue/multi-class ultra-performance liquid chromatography–tandem mass spectrometry method has been validated for simultaneous analysis of 25 antibiotic residues belong to sulfonamides, macrolides, and quinolones groups, as well as griseofulvin and trimethoprim, in Iranian feta cheese samples. Two specific precursor – product ion transitions were acquired per target compound by a positive electrospray ionisation in multiple reaction monitoring mode. Results were obtained as follows: limit of detection (LOD) and limit of quantification (LOQ) were respectively 3.3 ng g−1 and 10 ng g−1 (except for josamycin, LOD: 8.33 and LOQ: 25 ng g−1). Average recovery ranged between 70% and 120% and relative standard deviation of repeatability was lower than 20%. Finally, the method was applied to determination of target analytes in feta cheese samples obtained from the local hypermarkets and traditional dairy product markets in Tehran, Iran.

Occurrence of Cryptosporidium spp. in Traditional Milk and Dairy Products Supplied in Yazd City, Central Iran

Background: Cryptosporidium is one of the most important agents of food-borne diseases with gastrointestinal symptoms such as diarrhea in either livestock or humans. This protozoon can be transmitted to human through consuming contaminated raw milk and dairy products. The present study aimed to detect Cryptosporidium spp. in traditional raw cow milk, cream, and cheese consumed in Yazd city, Central Iran.&#x0D; Methods: Two hundred traditional (unpasteurized) milk and dairy samples were collected from five different regions of the studied area, including 100 traditional cow milk, 50 cow cheese, and 50 cow cream. DNA extraction was performed. Then, molecular detection was performed using the nested Polymerase Chain Reaction technique. Statistical analysis was performed using SPSS version 23.0.&#x0D; Results: The findings of this study showed that 11% samples were contaminated with Cryptosporidium spp., including 4.0% (4/100) milk, 18.0% (9/50) cream, and 18.0% (9/50) cheese (p&lt;0.05). Besides, parasite contamination was 8.8, 12.5, 12.8, 8.3, and 12.8% in the Center, North, East, South, and West of the studied region, respectively (p&gt;0.05).&#x0D; Conclusion: Due to the occurrence of Cryptosporidium spp. in unpasteurized dairy samples in Central Iran, developing and designing control and prevention programs is necessary against this parasite.