Raw Goat Milk Research Articles

Antimicrobial and antioxidant potential of indigenous lactic acid bacteria from raw goat milk and dahi

Antimicrobial and antioxidant potential of indigenous lactic acid bacteria from raw goat milk and dahi

Сравнительная характеристика молока коз разных пород

The article presents data on the study of milk productivity, qualitative composition and properties of milk of goats of local and Czech breeds. Goat milk of the compared groups of animals has high organoleptic, physicochem‑ ical and technological properties and meet the requirements of GOST 32940‑2014 “Raw goat milk. Technical conditions”.

Comparative Study of Aflatoxin M1 Carry-Over from Feed to Raw ‎Milk in Cow, Buffalo, Sheep, and Goats in Different Areas of ‎Baghdad Province

Mycotoxin aflatoxin B1 (AFB1) is a threat to food safety and human health because it is present in animal feed and is metabolized into aflatoxin M1 (AFM1), a more toxic form, during lactation. The aim of this study was to quantify AFM1 concentrations in raw milk of buffalos, cows, sheep, and goats sampled randomly from four regions within Baghdad ‎Province, Iraq, and to compare these levels with the maximum allowable levels set forth by the ‎European Commission (EC), the Iraqi Standard Specification (IQS), and the food and Drug Administration (FDA). The carry-over of AFB1 from feed to AFM1 in milk were also calculated for each of the ‎studied species. A total of 200 random samples, including 50 each from cows, buffaloes, ‎sheep, and goats, were collected from farms located in Zu'afraniya, Nahrawan, Abu Ghraib, and ‎Fedhalia regions. AFM1 and AFB1 concentrations were determined using the ‎enzyme-linked immunosorbent assay (ELISA). Raw milk samples from cows, sheep, buffaloes, and goats were all found to have AFM1 concentrations that were below the limits set by the EC, IQS, and FDA. Animal feed samples, on the other hand, had AFB1 concentrations of 10.08, 5.95, 4.27, and 7.10 ppb for ‎buffaloes, cows, sheep, and goats, respectively. The observed carry-over rates ranged from 0.36% ‎in goats to 0.78% in buffaloes to 0.66% in cows. Multiple factors, including animal species, ‎are considered, and it is determined that a universal carry-over equation cannot be applied to all cases. ‎Therefore, it is essential to regularly monitor AFM1 levels in milk from various animal species in order to ‎lessen potential health risks. Furthermore, the study suggests enhancing agricultural and veterinary ‎practices to better regulate feed quality for dairy animals‎‎‎‎.

INVESTIGATIONS REGARDING THE PRESENCE OF MICROORGANISMS IN THE MILK FOOD PRODUCTS COMMERCIALIZED IN REPUBLIC OF MOLDOVA

"The scientific research reflected in this study constituted the determination of microorganisms in some categories of milk used in human consumption: raw cow milk and raw goat milk, pasteurized milk sold in the store according to the indicators of the total number of germs, microscopy and bacteriology. The recorded results of the number of bacterioscopic microorganisms, microbial colonies after the classification results and milk categories were evaluated, which recorded various microbiological values of a normal bacterial microflora in the milk food product. The bacterioscopic and bacteriological values obtained allow consumers to be safe and use this food product in their consumption."

The Bacteriocin-like Inhibitory Substance Producing Lacticaseibacillus paracasei LPa 12/1 from Raw Goat Milk, a Potential Additive in Dairy Products

Goat milk is gradually becoming the preferred milk by consumers worldwide, including Slovakia. It is also demanded as a functional and/or nutraceutical drink as it is rich in bioactive components. However, another new development is the research into the beneficial autochthonous strains used to enrich goat dairy products. Among individual species, representatives in raw goat milk are also involved in lacticaseibacilli. Bacteriocin-like inhibitory substance-producing Lacticaseibacillus paracasei LPa 12/1 was isolated from raw goat milk. This study focuses on its potential as a new additive in dairy products. No mortality was found when checking the safety of the LPa 12/1 strain using Balb/c mice. The strain reached higher counts in ewe–goat milk yoghurt (up to 6.1 cfu/g log 10) than in cow milk yoghurt (almost 5.0 cfu/g log 10). Cow milk yoghurts remained in more stable consistency after LPa 12/1 supplementation compared with ewe–goat milk yoghurts, although specific organoleptic tests were not performed. However, LPa 12/1 has survived sufficiently in both types of yoghurts. This bacteriocin-like inhibitory substance-producing strain LPa 12/1 in its encapsulated form applied in yoghurts seems suitable to supplement dairy products.

Multi-residue detection of antibiotics in migratory goat milk and human health risk assessment in Western Himalayan region, India

Occurrence of antibiotics in animal sourced foods not only affects economy but also poses potential health risks. The present study aimed to validate simultaneous detection of amoxicillin, penicillin – G and enrofloxacin in raw migratory goat milk (N = 223) by HPLC-DAD and assess human health risks in Western Himalayan region, India. The analytical method was found to be linear (R2 > 0.99), accurate (recoveries > 80 %), precise (RSD < 10 %), and sensitive (CCα, 0.92–1.61 ng/mL) with LOQ values well below the MRLs. Antibiotic residues were detected in 11 (4.9 %) samples, and 9/11 (81.8 %) samples had levels above MRLs. Human health risk assessments based on comparison of estimated daily intakes with acceptable daily intakes of antibiotics revealed that there are no acute health risks to adults and children at current levels of contamination. However, % contribution to ADI for enrofloxacin and penicillin-G were significantly higher in children. Therefore, keeping in view, availability and routine consumption of goat milk especially by families of nomadic pastoralists in Himalayan region, children may be at a greater risk than adults. Hence, the present study highlights the need for monitoring of goat milk for contaminants, and education of nomadic pastoralists to meet food safety standards and for protection of human health.

Lactic acid bacteria from artisanal raw goat milk cheeses: technological properties and antimicrobial potential.

In cheese-making, a starter culture composed of adequately chosen lactic acid bacteria (LAB) may be suitable to ensure the rapid acidification of milk, improve textural and sensory characteristics, and avoid pathogen proliferation. In this work, 232 LAB isolates collected from artisanal goat's raw milk cheeses produced in Portugal were evaluated for their antimicrobial capacity (at 10 and 37°C), as well as their acidifying and proteolytic properties. Among the 232 isolates, at least 98% of those isolated in De Man- Rogosa-Sharpe (MRS) agar presented antagonism against Listeria monocytogenes, Salmonella Typhimurium, or Staphylococcus aureus, whereas less than 28.1% of M17-isolated LAB showed antagonism against these pathogens. M17-isolated LAB displayed better results than MRS ones in terms of acidifying capacity. As for the proteolytic assay, only 2 MRS isolates showed casein hydrolysis capacity. Principal component analyses and molecular characterization of a subset of selected isolates were conducted to identify those with promising capacities and to correlate the identified LAB genera and species with their antimicrobial, acidifying, and/or proteolytic properties. Lactococcus strains were associated with the highest acidifying capacity, whereas Leuconostoc and Lacticaseibacillus strains were more related to antimicrobial capacities. Leuconostoc mesenteroides, Lactococcus lactis, and Lacticaseibacillus paracasei were the predominant organisms found. The results of this work highlight various strains with pathogen inhibition capacity and suitable technological properties to be included in a customized starter culture. In future work, it is necessary to appropriately define the starter culture and implement it in the cheese-making process to evaluate if the in-vitro capacities are observable in a real food system.

Human Health Risk Assessment of Cd, Cu, Pb and Zn through Consumption of Raw goat's Milk in Jijel province (Algeria).

&lt;p&gt;Contamination of the food chain by toxic metals is one of the main concerns for human health. Milk is part of a balanced diet; essential for proper growth, but can also contains hazardous chemicals and contaminants including heavy metals which can be a risk for health. The aim of this study is to estimate the concentration of heavy metals in goat’s milk and to assess infants and children health risks related to milk consumption in Jijel province. Metals, namely Cd, Cu, Pb and Zn were determined by FAAS. In parallel, an online survey was carried out to estimate the daily consumption of milk. Then, non-carcinogenic and carcinogenic health risk values were calculated. The results indicated common to low levels of essential elements (Cu: 0.05 ± 0.001 mg/kg, Zn: 1.87 ± 0.069 mg/kg) in comparison with toxic elements (Cd: 0.018 ± 0.001 mg/kg, Pb: 0.38 ± 0.004 mg/kg). Cadmium content bordered its limit (0.01mg/kg), whereas, lead was higher twenty time the permissible limit. While, daily estimated intake of lead exceeds the limit value (282.35%), target hazard quotient and hazard index of the mixture were below one the safe limit, representing the absence of non-carcinogenic risk. Contrariwise, the carcinogenic risk of Pb and Cd, and their cumulative risk were observed higher than the acceptable limit (Pvalue &amp;lt; 0.001). Based on these results, the consumption of goat’s milk in Jije lprovince seems to be not safe for infants.&lt;/p&gt;&#x0D;

Quantification of cow milk in adulterated goat milk by HPLC-MS/MS using N-acetylglucosamine as a reliable biomarker of cow milk

This study aimed to develop a non-protein-based method for quantify cow milk in adulterated goat milk. The raw cow milk and raw goat milk samples were mixed separately with the same volume of cold acetone and centrifuged to remove their proteins. The supernatants were evaporated, and the residues were derivatized by silylation followed by GC-MS analysis. N-acetylglucosamine was identified as a thermostable non-protein biomarker of cow milk. Its concentration in the raw cow milk (146.7 mg/L) was 32 times higher than that in the raw goat milk. On this basis, a HPLC-MS/MS method using positive-ion electrospray ionization in parallel reaction monitoring mode was developed for quantifying cow milk in adulterated goat milk by determining peak area of the biomarker. The method showed good linearity over cow milk concentrations of 1–100% and could detect as low as 0.3% cow milk in adulterated goat milk. Besides, the method was characterized by a simple sample pretreatment process, rapid detection, high accuracy, and high precision. With this method, a sample could be analyzed in 10 min. The present study demonstrated the feasibility of quantifying cow milk in adulterated goat milk using N-acetylglucosamine as a biomarker of cow milk.

Effect of flower extract of Roselle (Hibiscus sabdariffa L) on microbial quality of raw milk of Etawa goats

Effect of flower extract of Roselle (Hibiscus sabdariffa L) on microbial quality of raw milk of Etawa goats

Dynamic Modelling to Describe the Effect of Plant Extracts and Customised Starter Culture on Staphylococcus aureus Survival in Goat's Raw Milk Soft Cheese.

This study characterises the effect of a customised starter culture (CSC) and plant extracts (lemon balm, sage, and spearmint) on Staphylococcus aureus (SA) and lactic acid bacteria (LAB) kinetics in goat's raw milk soft cheeses. Raw milk cheeses were produced with and without the CSC and plant extracts, and analysed for pH, SA, and LAB counts throughout ripening. The pH change over maturation was described by an empirical decay function. To assess the effect of each bio-preservative on SA, dynamic Bigelow-type models were adjusted, while their effect on LAB was evaluated by classical Huang models and dynamic Huang-Cardinal models. The models showed that the bio-preservatives decreased the time necessary for a one-log reduction but generally affected the cheese pH drop and SA decay rates (logDref = 0.621-1.190 days; controls: 0.796-0.996 days). Spearmint and sage extracts affected the LAB specific growth rate (0.503 and 1.749 ln CFU/g day-1; corresponding controls: 1.421 and 0.806 ln CFU/g day-1), while lemon balm showed no impact (p > 0.05). The Huang-Cardinal models uncovered different optimum specific growth rates of indigenous LAB (1.560-1.705 ln CFU/g day-1) and LAB of cheeses with CSC (0.979-1.198 ln CFU/g day-1). The models produced validate the potential of the tested bio-preservatives to reduce SA, while identifying the impact of such strategies on the fermentation process.

Investigation of the presence of some antibiotics in Raw Goat milk collected from Ankara, Kırıkkale and Çankırı provinces

Antibiotics used in food producing-animals may cause residual problems in food in terms of public health. This situation can lead to serious problems in terms of human health. Raw milk is one of the foods that are likely to contain antibiotics, even in trace amounts. This study aimed to determine the residue levels of commonly used antibiotics of raw goat's milk samples offered for sale in Ankara, Çankırı and Kırıkkale. One active ingredient was selected from the five most commonly used antibiotic groups in animals and it determined the residue levels of these substances in milk. For this purpose, within one year and in two different periods, 150 raw goat milks analyzed in terms of antibiotics using HPLC method. The values for enrofloxacin, sulfamethoxazole, tylosin, penicillin G and oxytetracycline were 7.9, 9.7, 11.5, 5.4 and 7.3 minutes for retention times, 1.47, 0.8; 7.51; 2.69 and 8.89 µg/L for limit of detection (LOD) and 4.47, 2.44, 22.78, 8.16 and 26.96 µg/L for limit of quantification (LOQ), respectively. No antibiotic residues were detected in the goat milk samples. It is predicted that the higher resistance of goats to diseases compared to other milk-producing animals, and therefore the lower use of antibiotics in these animals, leads to this result. The findings obtained as a result of this study are valuable in terms of public health. It is important that no antibiotic residues are found in the analyzes.

Molecular surveillance of Toxoplasma gondii in raw milk and Artisan cheese of sheep, goat, cow and water buffalo origin

This study is aimed at investigating the molecular prevalence of Toxoplasma gondii in raw milk and cheese of different animal species (sheep, goat, cow and water buffalo) in Kayseri Province, Türkiye, to provide a preliminary assessment for contamination risk. A total of 200 milk and cheese samples were analysed by real‐time PCR. Toxoplasma gondii DNA was detected in two (8%) ewes and one (4%) goat raw milk sample, while none of the cheese samples were positive. These results indicated that the presence of T. gondii DNA in raw milk samples sold in Kayseri Province might be a risk factor for public health.

The influence of grazing and indoor systems on goat milk, brined cheese and whey quality

This study aimed to investigate whether diet and different goat production systems affect the quality of milk, white-brined cheese and whey. It also aimed to determine the suitability of goat's milk for the production of white-brined cheese. The physicochemical composition and hygienic quality of raw goat's milk were studied, as well as the fatty acid profile and nutritional indices of milk and white-brined cheese. Traditional white-brined cheeses were produced from bulk goat milk from two farms in three samples. The results confirmed that different husbandry systems and diets influence the physicochemical composition of goat milk and cheese and their fatty acid profile. Milk and cheese from grazing goats contained significantly more (p&lt;0.05) fat, protein, total solids and a higher percentage of cheese yield. Nutritional indices were also more favourable, with a lower atherogenic (AI) and thrombogenic (TI) index and a higher health-promoting index (HHP) and hypocholesterolemic/hypercholesterolemic ratio (HH). Goat grazing contributed to a higher content of n-3 fatty acids in milk and cheese and thus to a lower n-6/n-3 ratio. Cheese-making efficiency and protein recovery in the curd (%REC) was better with pasture milk, whereas fat recovery was better with milk from housed goats. Consumers rated the unripened white cheeses from both production systems the highest. In addition, the production of white cheese with brine results in good quality whey with significant health benefits. Natural pasture provides significantly more benefits to goats than confinement, especially in the early stages of use. This contributes to the high nutritional value of goat's milk, cheese and whey.

Identification and characterization of goat milk key flavor compounds and their precursors in electron beam irradiation and pasteurization on raw

The electron beam irradiation causes changes in goat milk flavor, which may arise from complex reactions such as fat oxidation. This study aimed to investigate the effects of electron beam irradiation and pasteurization on thiobarbituric acid reactive substance values and the fatty acid composition in goat milk. The multivariate analysis of aroma compounds in goat milk was performed using electron nose and Gas Chromatography and Mass Spectrometry (GC–MS). The results showed that both conventional heat treatments, including pasteurization and electron beam irradiation, resulted in fat content alteration in goat milk. The degree of fat oxidation was proportional to the irradiation dose, with a significant increase in saturated fatty acid content and a significant decrease in unsaturated fatty acid content after irradiation. The multivariate statistical analysis showed that the difference in flavor between milk treated with a high dose (5 kGy) of radiation and raw goat milk was larger. Further, 2,4-dimethyl-1-heptene, 3-methyl pentane, 3,3,5-trimethyl heptane, 2-pentanone, and 1-octene might be the characteristic substances accounting for the flavor difference between raw goat milk, pasteurized milk, and irradiated milk. C10:0, C12:0, C14:0, C16:1, C17:0, and C18:1n9t fatty acids might be the main precursors for the formation of off-flavors of irradiated milk. The results indicated that pasteurization and electron beam irradiation led to flavor alterations in goat milk, and high doses of irradiation might intensify fat oxidation and produce more flavoring compounds.

Changes in Maillard reaction products, volatile substances and active proteins of goat milk under different heat treatments

Goat milk was heated at 75, 90, 105 and 120 °C for 5, 15 and 30 s and at 137 °C for 4 s to analyse the effect of different heat treatment conditions on Maillard products, active proteins and volatile compounds. The contents of furosine (FRS) and 5-hydroxymethylfurfural (5-HMF) increased with increased heat treatment temperature and time. The 5-HMF and FRS contents in ultra-high temperature sterilised (UHT) goat milk were 1.31 ± 0.03 mg L−1 and 130.22 ± 0.15 mg 100 g−1 protein, respectively. The contents of α-lactalbumin and lactoferrin in UHT goat milk were 81.74 ± 0.67 and 11.49 ± 0.18 mg L−1, respectively. Compared with raw goat milk, acids and esters content decreased and ketones and alcohols content increased during heat treatments. The reduction in octanoic, decanoic and other acids potentially improved odour. These results provide a theoretical basis for the further development of goat milk products.

TBE in Romania

Based on an epidemiological survey, human TBEV neuroinfections may have an endemic emergent course, and natural foci are in full territorial expansion. Identified risk areas are Tulcea district, Transylvania, at the base of the Carpathian Mountains and the Transylvanian Alps. TBE has been a notifiable disease since 1996. Surveillance of TBE is not done at the country level, only regionally in some counties (northern/central/western part, close to Hungary). The passive surveillance system was implemented in 2008. However, there is no regular screening and the relative risk of contracting this disease is unknown. In 1999, an outbreak of TBE in humans was recorded with a total of at least 38 human cases. The probable cause of the outbreak was goat milk and raw goat milk products. Subsequent studies to detect TBEV in ticks in the affected regions resulted in a non -specified number of TBEV isolates, which were described as belonging to the European subtype of TBEV. A publication of the neighboring Republic of Moldova described the existence of the Far-eastern subtype of TBEV just at the border to Romania.

TBE in Bulgaria

First cases of probable tick-borne encephalitis (TBE) were reported in 1961 by Andonov et al. in eastern regions of Bulgaria. Possible TBE cases with the typical two-wave fever, originating from consumption of raw goat milk, were described back in 1953 by Vaptzarov et al. in southern Bulgaria. Investigations in the 1960s were able to isolate 3 tick-borne encephalitis virus (TBEV) strains from Haemaphysalis punctata and 1 from Dermacentor marginatus ticks from goats and sheep in the district of Plovdiv. The antigenic properties of these 4 virus strains were identical to the highly virulent strain “Hypr” of the European subtype of TBEV (TBEV-EU).

Characteristics of the epidemic process of Lyme borreliosis in the Sverdlovsk district over a 20-year period

Relevance. The Sverdlovsk district is a tense natural focus for Lyme borreliosis (LB) with a constantly recorded incidence that exceeds these indicators in the Russian Federation and the Ural Federal region several times. LB is registered on 56 of 59 administrative territories of the district. Currently, the count of LB in the Russian Federation includes both infections caused by Borrelia burgdorferi sensu lato group Borrelia and infections caused by Borrelia miyamotoi sensu lato group Borrelia.Aim. To characterize the epidemic process of LB in the territory of the Sverdlovsk district over a 20-year period (2002–2021).Materials and methods. The paper uses data from federal and regional statistical observations, reporting materials of the Department of Rospotrebnadzor in the Sverdlovsk district for 2002–2021, methods of statistical analysis.Results and discussion. During the follow–up period (2002–2021), the incidence rate of BL in the Sverdlovsk district exceeded the average long-term level in the Russian Federation by almost 3 times, and in the Ural Federal region – by 1.8 times. Among the mechanisms and ways of transmission of LB pathogens, the vector-borne mechanism dominated (84.5%), the share of the unidentified pathway was 15.4%, alimentary (when using raw goat's milk) – 0.1%. The duration of the epidemic season for LB in the district was 10 months (from March to December) with a peak incidence in June. Cases of LB were registered among people of different ages, with a predominance in the group of 60 years and older (39.1%). An analysis of the distribution of people with LB by social composition showed that pensioners prevailed among them – 36.3%, officials made up 27.8%, unemployed – 14.1%. Among the cases, a high proportion of schoolchildren and children under 7 years old were noted. It was found that erythematous and non-erythematous forms of LB are registered in the district, with a predominance of erythematous (64.5%). The main etiological agent of the erythematous form is Borrelia garinii, while the non-erythematous form is Borrelia miyamotoi and B. garinii. In the general structure of morbidity, the number of cases of LB is largely determined by the city inhabitants (92.9%). There were no fatal outcomes in LB in the territory of the district during the studied period.Conclusions. Due to the lack of vaccination of LB worldwide, the only strategy to reduce the incidence of LB is non-specific prevention and timely diagnosis of the disease, including data from epidemiological history, clinical and laboratory diagnostics. The long-term clinical and epidemiological and laboratory studies conducted by us in the Sverdlovsk district allowed us to characterize the main manifestations of the epidemic process of LB and to improve the diagnosis of the disease.

Tracking microbial quality, safety and environmental contamination sources in artisanal goat cheesemaking factories

A harmonised microbiological survey was performed in two artisanal factories of raw goat milk cheeses (A and B) located in the Andalusian region (Spain). A total of 165 different control points or samples (raw materials, final products, food-contact surfaces [FCS], and air) were examined as microbial and pathogen sources of contamination of artisanal goat raw milk cheeses. For raw milk samples analysed from both producers, the concentrations of aerobic-mesophilic bacteria (AMB), total coliforms, coagulase-positive Staphylococcus spp. (CPS), lactic-acid bacteria (LAB) and moulds and yeasts ranged between 3.48 and 8.59, 2.45–5.48, 3.42–4.81, 4.99–8.59 and 3.35–6.85 log cfu/mL respectively. For the same microbial groups, the analysis of raw milk cheeses revealed concentrations ranging from 7.82 to 8.88, 2.00–6.82, 2.00–5.28, 8.11–9.57 and 2.00–5.76 log cfu/g, respectively. Although the raw material analysed from producer A presented higher microbial loads and between-batch variability, it was B the producer with the most loaded final products. Regarding the microbial air quality, the fermentation area, storage room, milk reception and packaging room were the most AMB loaded places, while the ripening chamber was the area with higher fungal loads in bioareosol from both producers. Conveyor belts, cutting machine, storage boxes and brine tank were highlighted as the most contaminated FCS evaluated. Staphylococcus aureus was the only pathogen detected within the set of 51 isolates from samples as revealed by MALDI-TOF and molecular PCR, with a prevalence of 12.5% for samples from the producer B. The public health risk attributed to the consumption of artisanal goat cheese should not be neglected, and may consider the whole cheesemaking processing chain, from microbiological quality of raw milk to the ready-to-eat final product, especially concerning the presence of S. aureus.