scholarly journals Low and High-Intensity Ultrasound in Dairy Products: Applications and Effects on Physicochemical and Microbiological Quality

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1688
Author(s):  
América Chávez-Martínez ◽  
Raúl Alberto Reyes-Villagrana ◽  
Ana Luisa Rentería-Monterrubio ◽  
Rogelio Sánchez-Vega ◽  
Juan Manuel Tirado-Gallegos ◽  
...  

Milk and dairy products have a major role in human nutrition, as they contribute essential nutrients for child development. The nutritional properties of dairy products are maintained despite applying traditional processing techniques. Nowadays, so-called emerging technologies have also been implemented for food manufacture and preservation purposes. Low- and high-intensity ultrasounds are among these technologies. Low-intensity ultrasounds have been used to determine, analyze and characterize the physical characteristics of foods, while high-intensity ultrasounds are applied to accelerate particular biological, physical and chemical processes during food product handling and transformation. The objective of this review is to explain the phenomenology of ultrasounds and to detail the differences between low and high-intensity ultrasounds, as well as to present the advantages and disadvantages of each one in terms of the processing, quality and preservation of milk and dairy products. Additionally, it reviews the rheological, physicochemical and microbiological applications in dairy products, such as raw milk, cream, yogurt, butter, ice cream and cheese. Finally, it explains some methodologies for the generation of emulsions, homogenates, crystallization, etc. Currently, low and high-intensity ultrasounds are an active field of study, and they might be promising tools in the dairy industry.

2014 ◽  
Vol 77 (2) ◽  
pp. 299-307 ◽  
Author(s):  
OLIVIER KAMANA ◽  
SIELE CEUPPENS ◽  
LIESBETH JACXSENS ◽  
ANASTASE KIMONYO ◽  
MIEKE UYTTENDAELE

Milk is a valuable and nutritious food product that can partially fulfill the rising food demand of the growing African population. The microbiological status of milk and derived products was assessed throughout the milk and dairy chain in Rwanda by enumeration of the total mesophilic count, coliforms, and Staphylococcus aureus and detection of Salmonella and Listeria monocytogenes. The quality of raw milk was satisfactory for the majority of samples, but 5.2% contained Salmonella. At the processing level, the total mesophilic count and coliform numbers indicated ineffective heat treatment during pasteurization or postpasteurization contamination. Increasing bacterial counts were observed along the retail chain and could be attributed to insufficient temperature control during storage. Milk and dairy products sold in milk shops were of poor and variable microbiological quality in comparison with the pasteurized milk sold in supermarkets. In particular, the microbiological load and pathogen prevalence in cheese were unacceptably high.


Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.


2015 ◽  
Vol 143 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Anka Popovic-Vranjes ◽  
Milka Popovic ◽  
Marija Jevtic

Contrary to the safe practices of milk pasteurization or sterilization, which effectively reduce foodborne outbreaks incidence associated with raw milk and dairy products use, outbreaks caused by such products continue to occur. Despite this fact, a worldwide movement advocating for the rights of raw milk and cheese selling and consumption, due to their specific nutritive characteristics, has strengthened significantly in recent years. Traditional agricultural manufacturers from Serbia still sell products related to thermally unprocessed milk, such as cottage cheese and raw cream. In AP Vojvodina during the period of 1981-2010 a total of 179 foodborne outbreaks were reported, where the incriminated cause of the outbreak were milk or diary. In 126 (70.39%) outbreaks, totaling 2276 sick individuals and one casualty, it was confirmed that the incriminated food was from the group of dairy products. In 48 instances (26.82%), bacteriological tests confirmed that milk and dairy products were excluded as the outbreak causes, while in another 5 (2.79%) outbreaks, microbiological analysis of food failed to confirm any relation to the actual epidemiological instances. In some cases, bacteriological testing of incriminated foods was not possible. In the cases of outbreaks associated with the consumption of milk and dairy products, traditional raw milk products were cited as being used. Consumption of unpasteurized milk and cheese represents public health threat. National and international rules ensuring use of safe products for human consumption have to set rules of trade of thermally processed milk and products on the market.


2014 ◽  
Vol 38 (2) ◽  
pp. 9-16
Author(s):  
Najim Hadi Najim

     Milk and dairy products are fundamental components in the human diet and may be the principle way for entrance of Aflatoxin M1 (AFM1) in to the human body. All milk and dairy products samples were tested for the occurrence of AFM1 by the competitive ELISA technique. Out of 32 bovine raw milk samples that were collected from eight villages around Baghdad province, 32 samples (100 %) were contaminated with AFM1 ranging from 0.15 to 86.96ng/kg with mean value of 42.37±26.07 ng/kg, of which 17 samples were contaminated with concentrations < 50 ng/kg and 15 samples exceeded the maximum acceptable level of AFM1 in milk (50 ng/kg) imposed by the European legislation. The raw milk samples belonged to animals fed with composite and stored fodder as in Althahab Alabiadh, Radhwaniya and Fadhaliya villages had higher significantly AFM1 concentrations over all the other five villages (Grazing feed). All 32 (100%) locally produced soft white cheese samples analyzed were contaminated with AFM1 ranging from 31.84 to 89.44 ng/kg with the mean value of 59.92±17.03 ng/kg. Out of 32 locally produced yoghurt samples analyzed, 32 samples (100%) were contaminated with AFM1 ranging from 0.16 to 42.74 ng/kg with the mean value of 16.92±11.55 ng/kg. Thirty samples (100%) of the examined 30 imported UHT milk samples that were collected from different commercial companies in the province of Baghdad presented significantly  high contamination level with AFM1 that were found to range from 0.18 to 85.66 ng/kg.


1993 ◽  
Vol 56 (3) ◽  
pp. 256-259 ◽  
Author(s):  
A. EL MARRAKCHI ◽  
A. HAMAMA ◽  
F. EL OTHMANI

Examination of 227 samples of milk and dairy products for Listeria monocytogenes showed that raw milk and some Moroccan traditionally made dairy products such as Iben and raib (fermented milks) and jben (fresh cheese) were contaminated with this pathogen. L. monocytogenes was the only Listeria species isolated except in one case in which it was associated with Listeria innocua. Pasteurized milk, fresh cream, and fresh and ripened cheeses (industrially made) were free from L. monocytogenes.


2015 ◽  
Vol 7 ◽  
pp. 169-177 ◽  
Author(s):  
Azar Asadollahi Dehkordi ◽  
Elahe Tajbakhsh ◽  
Forough Tajbakhsh ◽  
Faham Khamesipour ◽  
Manouchehr Momeni Shahraki ◽  
...  

1980 ◽  
Vol 43 (7) ◽  
pp. 536-537 ◽  
Author(s):  
T. A. EL-BASSIONY

A total of 163 samples of milk and milk products (including raw milk, Damietta and Kareish cheese, hard and processed cheese, yogurt, butter and ice cream) were collected from Assiut City markets. Clostridium perfringens was detected in 45.5, 20, 30, 14.3, 20, 10, 50 and 20% of the examined samples, respectively, using SPS agar. With TSN agar, the organism was isolated from 72.7, 20, 30, 28.6, 50, 10, 50, and 30% of the samples, respectively. The mean value of the C. perfringens count using SPS agar was 53.6/ml, 40/g, 60/g, 14.3/g, 30/g, 1.4/g, 25/g and 8/ml of raw milk, Damietta and Kareish cheese, hard and processed cheese, yogurt, butter and ice cream samples, respectively, while the mean values of C. perfringens counts obtained with TSN agar were 76.4/ml, 170/g, 140/g, 42.9/g, 590/g, 2.9/g, 172.9/g, and 109/ml of examined samples, respectively. Milk and dairy products, if improperly handled, provide a means for transmission of C. perfringens to the consumer.


2013 ◽  
Vol 411-414 ◽  
pp. 2417-2422
Author(s):  
Yao Li Zhang ◽  
Jing Chen ◽  
Xin Zhong

Now, along with the improvement of people's living standard, more and more people quality safety problems of dairy products by the attention. Milk quality index basically has sensory indexes and physiochemical index, microbiological quality and harmful material residues and pollutants quantity four aspects. Regarding the enterprise, it wants to produce milk, besides should assured teaches defend in production of various indexes; outside the control of raw also cannot be ignored. The key points to control of raw comparison of raw index are to ensure effective method.In recent years, as environmental pollution increasingly heavier, antibiotics, making the wrong use already slowly pollution to harmful material variety of dairy products, in the milk antibiotic and heavy metal content has become the focus of people are indexes. First, in this paper introduces dairy products can exist of antibiotic types and the detection method, then to mercury as example, the paper introduces the current national state currently can several methods of determination of mercury, through the practical consideration, find a relatively simple, efficient, feasibility big test methods.


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