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Microbiological Quality of Raw Donkey Milk from Serbia and Its Antibacterial Properties at Pre-Cooling Temperature. Animals (Basel) 2023; 13:ani13030327. [PMID: 36766215 PMCID: PMC9913105 DOI: 10.3390/ani13030327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/13/2023] [Accepted: 01/14/2023] [Indexed: 01/18/2023] Open
Abstract
The aim of this study was to examine the microbiological quality of raw donkey milk of an indigenous Serbian breed as well as the changes in the microbial populations during storage at 4 °C. In addition, antibacterial activity of donkey milk against E. coli, L. monocytogenes and S. aureus at 15 °C as well as the content of the two main antibacterial proteins lysozyme and lactoferrin were investigated. Microbiological examination of 137 individual milk samples collected over a period of 21 months showed good microbiological quality since foodborne pathogens such as Salmonella spp. and L. monocytogenes were not detected in any of the analyzed samples, while the number of E. coli, Enterobacteriaceae, total coliform bacteria, sulfite-reducing Clostridia and aerobic sporogenic bacteria was below the limit of quantification (<1 cfu mL-1). During the six-days storage at 4 °C, total bacterial counts and the counts of lactic acid bacteria remained at the initial level while pathogenic bacteria were not detected. The strongest antibacterial activity of the tested milk was observed against E. coli, while S. aureus was the least sensitive to milk antibacterial compounds. Although further research is needed to fully elucidate the antibacterial mechanism and synergistic activity of different compounds in donkey milk, the high content lysozyme (2.63 ± 0.03 g L-1) and lactoferrin (15.48 mg L-1) observed in tested milk could contribute to its strong antibacterial activity and extension of the storage period during which it can be safely consumed.
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Papademas P, Mousikos P, Aspri M. Valorization of donkey milk: Technology, functionality, and future prospects. JDS COMMUNICATIONS 2022; 3:228-233. [PMID: 36338810 PMCID: PMC9623768 DOI: 10.3168/jdsc.2021-0175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/22/2022] [Indexed: 05/05/2023]
Abstract
Donkey milk has been in the spotlight for the past 2 decades, mainly because of its potential as a functional food that has positive effects on human health. Nevertheless, challenges remain regarding farming practices, milk yield and milk processing, the introduction of minimal technology, and the use of donkey milk to produce dairy products. In this review, we highlight the fact that interdisciplinary research is needed to provide the scientific community with new knowledge on donkey milk, especially through human clinical trials.
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Clawin‐Rädecker I, De Block J, Egger L, Willis C, Da Silva Felicio MT, Messens W. The use of alkaline phosphatase and possible alternative testing to verify pasteurisation of raw milk, colostrum, dairy and colostrum-based products. EFSA J 2021; 19:e06576. [PMID: 33968255 PMCID: PMC8085980 DOI: 10.2903/j.efsa.2021.6576] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pasteurisation of raw milk, colostrum, dairy or colostrum-based products must be achieved using at least 72°C for 15 s, at least 63°C for 30 min or any equivalent combination, such that the alkaline phosphatase (ALP) test immediately after such treatment gives a negative result. For cows' milk, a negative result is when the measured activity is ≤ 350 milliunits of enzyme activity per litre (mU/L) using the ISO standard 11816-1. The use and limitations of an ALP test and possible alternative methods for verifying pasteurisation of those products from other animal species (in particular sheep and goats) were evaluated. The current limitations of ALP testing of bovine products also apply. ALP activity in raw ovine milk appears to be about three times higher and in caprine milk about five times lower than in bovine milk and is highly variable between breeds. It is influenced by season, lactation stage and fat content. Assuming a similar pathogen inactivation rate to cows' milk and based on the available data, there is 95-99% probability (extremely likely) that pasteurised goat milk and pasteurised sheep milk would have an ALP activity below a limit of 300 and 500 mU/L, respectively. The main alternative methods currently used are temperature monitoring using data loggers (which cannot detect other process failures such as cracked or leaking plates) and the enumeration of Enterobacteriaceae (which is not suitable for pasteurisation verification but is relevant for hygiene monitoring). The inactivation of certain enzymes other than ALP may be more suitable for the verification of pasteurisation but requires further study. Secondary products of heat treatment are not suitable as pasteurisation markers due to the high temperatures needed for their production. More research is needed to facilitate a definitive conclusion on the applicability of changes in native whey proteins as pasteurisation markers.
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Optimization of UV-C Processing of Donkey Milk: An Alternative to Pasteurization? Animals (Basel) 2020; 11:ani11010042. [PMID: 33379250 PMCID: PMC7824723 DOI: 10.3390/ani11010042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/14/2020] [Accepted: 12/17/2020] [Indexed: 11/16/2022] Open
Abstract
The effect of UV-C light technology on the inactivation of six foodborne pathogens inoculated in raw donkey milk was evaluated. Fresh raw donkey milk was artificially inoculated with the following foodborne pathogens-L. inoccua (NCTC 11288), S. aureus (NCTC 6571), B. cereus (NCTC 7464), Cronobacter sakazakii (NCTC 11467), E. coli (NCTC 9001), Salmonella enteritidis (NCTC 6676)-and then treated with UV-C doses of up to 1300 J/L. L. innocua was the most UV-C-resistant of the bacteria tested, requiring 1100 J/L for complete inactivation, while the rest of the bacteria tested was destructed in the range of 200-600 J/L. Results obtained from this study indicate that UV-C light technology has the potential to be used as a non-thermal processing method for the reduction of spoilage bacteria and foodborne pathogens that can be present in raw donkey milk.
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Papademas P, Kamilari E, Aspri M, Anagnostopoulos DA, Mousikos P, Kamilaris A, Tsaltas D. Investigation of donkey milk bacterial diversity by 16S rDNA high-throughput sequencing on a Cyprus donkey farm. J Dairy Sci 2020; 104:167-178. [PMID: 33162091 DOI: 10.3168/jds.2020-19242] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022]
Abstract
The interest in milk originating from donkeys is growing worldwide due to its claimed functional and nutritional properties, especially for sensitive population groups, such as infants with cow milk protein allergy. The current study aimed to assess the microbiological quality of donkey milk produced in a donkey farm in Cyprus using culture-based and high-throughput sequencing techniques. The culture-based microbiological analysis showed very low microbial counts, whereas important food-borne pathogens were not detected in any sample. In addition, high-throughput sequencing was applied to characterize the bacterial communities of donkey milk samples. Donkey milk mostly composed of gram-negative Proteobacteria, including Sphingomonas, Pseudomonas, Mesorhizobium, and Acinetobacter; lactic acid bacteria, including Lactobacillus and Streptococcus; the endospores forming Clostridium; and the environmental genera Flavobacterium and Ralstonia, detected in lower relative abundances. The results of the study support existing findings that donkey milk contains mostly gram-negative bacteria. Moreover, it raises questions regarding the contribution of (1) antimicrobial agents (i.e., lysozyme, peptides) in shaping the microbial communities and (2) bacterial microbiota to the functional value of donkey milk.
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Affiliation(s)
- P Papademas
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3036, Cyprus.
| | - E Kamilari
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3036, Cyprus
| | - M Aspri
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3036, Cyprus
| | - D A Anagnostopoulos
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3036, Cyprus
| | - P Mousikos
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3036, Cyprus
| | - A Kamilaris
- Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS), University of Twente, Enschede, 7522 NB, the Netherlands; Research Centre on Interactive Media, Smart Systems and Emerging Technologies-RISE, Nicosia 1066, Cyprus
| | - D Tsaltas
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3036, Cyprus.
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Luoyizha W, Wu X, Zhang M, Guo X, Li H, Liao X. Compared analysis of microbial diversity in donkey milk from Xinjiang and Shandong of China through High-throughput sequencing. Food Res Int 2020; 137:109684. [PMID: 33233260 DOI: 10.1016/j.foodres.2020.109684] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/18/2020] [Accepted: 09/06/2020] [Indexed: 12/26/2022]
Abstract
Donkey milk has received increasing attention from consumers and dairy industry because of its nutritional value, health benefits, and proximity to human milk. Microbial diversity in donkey milk has a great impact on its quality and safety, however, microbiota in donkey milk from the major donkey-breeding regions of China have not been well documented. In this study, bacterial communities in donkey milk from Yopurga County in Western China (XJ), and Dong'e County in Eastern China (SD) were determined using high-throughput sequencing. Major phyla identified in the two donkey milk groups consistently included Acinetobacter, Proteobacteria, Firmicutes, and Bacteroidetes but with very different abundance for each phylum. Prevelence of genera was found to be diverse between the two groups, with Macrococcus and Acinetobacter dominating in the XJ samples while Streptococcus, Pseudoclavibacter, and Pseudomonas being the most abundant ones in the XJ samples. Alpha diversity analysis showed that there was significant difference in richness between the two sample groups but no difference in bacterial community diversity or coverage. The presence of possible harmful bacteria and lactic acid bacteria in donkey milk in this study provides the microbial profiles of pathogens and spoilage bacteria that need to be controlled and proposes possible utilization of beneficial microbial resources for the future.
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Affiliation(s)
- Wahafu Luoyizha
- College of Food Science and Nutrition Engineering, China Agricultural University, Beijing 100083, PR China; College of Life Science and Technology, Xinjiang University, Xinjiang 830046, PR China
| | - Xiaomeng Wu
- College of Food Science and Nutrition Engineering, China Agricultural University, Beijing 100083, PR China
| | - Ming Zhang
- Xinjiang Yukunlun Natural Food Engineering Co. Ltd., Xinjiang 8444400, PR China
| | - Xingfeng Guo
- College of Agronomy, Liaocheng University, Shandong 252000, PR China
| | - Hui Li
- Institute of Quality Standard and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
| | - Xiaojun Liao
- College of Food Science and Nutrition Engineering, China Agricultural University, Beijing 100083, PR China
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Faccia M, D’Alessandro AG, Summer A, Hailu Y. Milk Products from Minor Dairy Species: A Review. Animals (Basel) 2020; 10:ani10081260. [PMID: 32722331 PMCID: PMC7460022 DOI: 10.3390/ani10081260] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/13/2020] [Accepted: 07/22/2020] [Indexed: 12/16/2022] Open
Abstract
Milk processing is one of the most ancient food technologies, dating back around 6000 BC. The majority of dairy products are manufactured from cows, buffaloes, goats, and sheep; their production technologies are mostly standardized and have been widely investigated. Milk and dairy products from minor species are less important under the economic point of view, but they play a fundamental social role in many marginal and poor areas. Due to scarce interest of the dairy industry, their technological characteristics and related issues have been investigated less. Recently, the increasing interest toward ethnic foods and food biodiversity is helping these minor products to emerge from the "darkness" in which they have remained for long time. Some of them are increasingly seen as useful for the valorization of marginal areas, while others are recognized as innovative or healthy foods. The present review aims to resume the most recent knowledge about these less-known dairy products. The first part summarizes the main technological properties of equine, camel, and yak milk with a view to processing. The second is a survey on the related dairy products, both the traditional ones that have been manufactured for a long time and those that have been newly developed by food researchers.
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Affiliation(s)
- Michele Faccia
- Department of Soil, Plant and Food Sciences (DiSSPA), University of Bari, Via Amendola 165/A, 70126 Bari, Italy
- Correspondence: ; Tel.: +39-080-544-3012
| | | | - Andrea Summer
- Department of Veterinary Science (DSMV), University of Parma, Via del Taglio 10, 43126 Parma, Italy;
| | - Yonas Hailu
- School of Animal and Range Sciences, Haramaya University, P.O. Box 138, Dire Dawa 3000, Ethiopia;
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Conte F, Panebianco A. Potential Hazards Associated with Raw Donkey Milk Consumption: A Review. INTERNATIONAL JOURNAL OF FOOD SCIENCE 2019; 2019:5782974. [PMID: 31275956 PMCID: PMC6582899 DOI: 10.1155/2019/5782974] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/20/2019] [Accepted: 04/02/2019] [Indexed: 12/02/2022]
Abstract
Donkey milk can be used as a substitute for infants and children who suffer from cow milk proteins intolerance and multiple food hypersensitivity. Up to date, this is one of the main reasons why donkey milk has become a substantial area for reasearch, with an increase over the the last fifteen years. In donkey milk chain, risk analysis should be the object of particular attention because children are the main consumers of this food. In fact, this process is one of the main tool to achieve a high level of protection of human health and life; thus, the most important safety hazards should be monitored in order to attain this goal. This review focuses on the main hazards possibly present in raw donkey milk, including bacteria, fungal toxins, parasites, and chemical pollutants. Literature data have been considered, including some information that is not provided in the international literature. In the authors' opinion, the current scientific knowledge should be improved, with the aim of allowing a suitable risk assessment along the whole donkey milk chain. However, in the meantime, the competent authorithies must carry out more stringent official controls, with particular attention given to the level of primary production. The issue of a traceability system in donkey milk chain should be considered of paramount importance.
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Affiliation(s)
- F. Conte
- Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - A. Panebianco
- Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
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