Influence of thermal and other manufacturing stresses on retinol isomerization in milk and dairy products

1998 ◽  
Vol 65 (2) ◽  
pp. 253-260 ◽  
Author(s):  
GIANFRANCO PANFILI ◽  
PAMELA MANZI ◽  
LAURA PIZZOFERRATO

An analytical procedure, based upon HPLC, has been used to determine the degree of isomerization of retinol (vitamin A) in various dairy products. In raw milks, which are not subjected to thermal processing, there was no conversion of the predominant all-trans-isomers to cis-isomers in samples from various species. Pasteurized milks with mild heat treatment (high quality milk) had an average 13-cis[ratio ]all-trans ratio of 2·6%, while pasteurized milk treated for 15 s at temperatures ranging from 72 to 76°C had an average ratio of 6·4%. Milk subjected to more severe heat treatments had a higher degree of isomerization (UHT milk, 15·7%; sterilized milk, 33·5%), consistent with increased thermal conversion of the retinol isomers. In pasteurized and UHT cream, the increase in 13-cis-isomer was also a consequence of heat treatment (pasteurized cream, 3·0%; UHT cream, 14·4%). The presence of cis isomers in fermented milk suggests that fermentation processes, directly or indirectly, can induce cis–trans isomerization. In the cheeses analysed, the extent of retinol isomerization ranged from 7·6 to 35·0%. Our results confirm the importance of individual isomers in evaluating the vitamin A status of dairy products.

AGROFOR ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Jagath JAYASINGHE ◽  
Samudra PATHIRANA ◽  
Dhammi DILHANI ◽  
Senevirathne NAVARATHNA ◽  
Manoj SINHAPURA ◽  
...  

Nuwara Eliya district is the leading fresh milk producing area in Sri Lanka. In the district, pesticides are widely applied for intensive cultivation of vegetables which leads to contamination of water and material used to feed cows. Contamination and health risk hazards of organophosphorus pesticide residues in milk and dairy products originated in the district were studied. Identification and quantification of eleven commonly used pesticides in 50 milk samples and 12 dairy product samples were performed using standard analytical methods and GC-MS technique. Results revealed that fresh milk contained residues of Prothiofos (0.0568±0.037 mg/kg), Diazinon (0.0378±0.009 mg/kg), Chlorpyrifos (0.0264±0.004 mg/kg), Profenofos (0.196±0.099 mg/kg), Fipronil (0.1906±0.188 mg/kg), Phenthoate (0.1012±0.110mgkg), Dimethoate (0.1196±0.201 mg/kg) and Tebuconazole (0.062±0.069 mg/kg) at higher levels than the recommended maximum residue levels (MRLs) of the World Health Organization. Sterilized milk (0.0115±0.000 mg/kg) and fermented milk (0.022±0.004 mg/kg) contained higher levels of Profenofos than the MRLs. Higher levels of Fipronil than MRLs were observed in pasteurized milk (0.086±0 mg/kg) and fermented milk (0.014±0.000 mg/kg) samples. Phenthoate at higher levels than MRL was reported in pasteurized milk (0.3645±0.402 mg/kg), sterilized milk (0.1405±0.197 mg/kg) and milk powder (0.0055±0.000 mg/kg). Moreover, Dimethoate content in fermented milk (0.087±0.012 mg/kg) was higher than the MRL. Routine monitoring of the above pollutants in food items including fresh milk and value added milk products is essential to prevent, control and reduce the pollution and to minimize the health risks to consumers.


Author(s):  
LA Rumyantseva ◽  
OV Vetrova ◽  
AV Istomin

Introduction. The article presents data on the role of milk and dairy products, including fermented milk products, in the human diet and reflects their important role in providing the body with proteins having a high essential amino acid content. In addition to all health benefits of milk, fermented dairy products have dietary and medicinal properties while their digestibility is higher than that of milk. Objective. To demonstrate the role of fermented milk products in human nutrition and benefits of fermented milk products enriched with probiotic microorganisms for preventive nutrition in the microbiocenosis of the gastrointestinal tract. Materials and methods. The article presents an analytical review of literary sources on the role of milk and dairy products, including fermented milk products, in human nutrition and provides information on the per capita production and consumption of milk and dairy products in the Russian Federation. It also addresses the problem of dysbiosis since fermented dairy technology can pose a serious microbiological risk related to favorable conditions for the growth of extraneous microorganisms coming from raw materials, starter cultures, and equipment during the production process. The absence of stringent quality standards for fermented milk products contributes to manufacturing of various counterfeit foods. Results. The article outlines the main provisions of the expert hygienic assessment of specialized food products for preventive nutrition for the purpose of their state registration on the example of fermented milk bioproducts, defines criteria for assessing the quality and safety of specialized products for dietary nutrition and requirements for technical documentation on these products, and provides the list of necessary documents for expert examination of hygiene and safety of specialized products for therapeutic and preventive nutrition. Conclusion. The permission to use novel fermented milk products as preventive nutrition foods shall be based on results of предassessing their compliance with the requirements of technical regulations of the Customs Union and the Eurasian Economic Union on the quality and safety of products and their raw materials, packaging and labeling.


1938 ◽  
Vol 9 (1) ◽  
pp. 17-21 ◽  
Author(s):  
A. E. Gillam ◽  
K. M. Henry ◽  
S. K. Kon ◽  
P. White

1. The vitamin A and carotene content of raw milk have been compared with that of milk from the same bulk after it had been commercially sterilized.2. For this purpose the fat was obtained by ether extraction from eleven samples of raw milk and from eleven corresponding samples of sterilized milk. As the sterilized milk had been previously homogenized it was not possible to churn it.3. The vitamin A and carotene content was estimated by colorimetric (Lovibond tintometer) and by spectrophotometric tests.3. The vitamin A and carotene content was estimated by colorimetric (Lovibond tintometer) and by spectrophotometric tests.4. The results showed that the efiect of the heat treatment was negligible, neither method demonstrating a loss in vitamin A, while for carotene only the colorimetric method indicated a loss of about 2 %.5. The vitamin A and carotene contents of sterilized milk were not decreased after storage for several weeks in a cool dark place.


2020 ◽  
pp. 20-23
Author(s):  
Olena LIAKHOVSKA

The dairy industry is one of the important components of the food industry in Ukraine. Significant dynamic and structural changes in the procurement, processing and foreign trade of milk and dairy products have been observed in recent years. Further prospects for the development of the dairy industry are formed under the influence of a decrease in agricultural harvesting of milk, a decrease in the volume of deep processing of milk (production of butter and cheese), changes in foreign trade. It is important to study the current state of the dairy industry and identify trends in its further development. The tendencies of milk procurement by agricultural enterprises and households of Ukraine are investigated. Over the years milk production in agriculture has been dynamically diminishing, with a shift to entrepreneurial forms of dairy farming. It has been noted that the decrease in milk production volume in recent years has influenced the dynamics of industrial production of dairy products. In particular, in recent years the production of cheese and butter has decreased significantly, and milk production has been characterized by unstable trends. The general characteristics of Ukraine's foreign trade in milk and dairy products are presented. In recent years, the value of the export-to-import ratio has been positive for most dairy products. Over the last year (2018), exports of butter, condensed milk and cream, condensed milk and cream and whey prevailed in Ukraine. At the same time, they imported more cheese and butter, fermented or fermented milk and cream. The main part of the exported dairy products was export of butter and milk and cream condensed, imported mainly cheese. It is established that the main problem of the dairy industry today is the low level of milk production. Therefore, financial and investment processes should be stimulated to build farms and increase livestock production at enterprises to offset losses from reduced milk production by households. At the same time, it is necessary to encourage deep processing of milk, in particular the production of butter (main export product) and cheese (to avoid import dependence).


2019 ◽  
Vol 122 (2) ◽  
pp. 172-185 ◽  
Author(s):  
Olivia L. van der Reijden ◽  
Valeria Galetti ◽  
Isabelle Herter-Aeberli ◽  
Michael B. Zimmermann ◽  
Christophe Zeder ◽  
...  

AbstractThe contribution of milk and dairy products to daily iodine intake is high but variable in many industrialised countries. Factors that affect iodine concentrations in milk and dairy products are only poorly understood. Our aim was to: (1) assess the effect of feed iodine concentration on milk iodine by supplementing five groups of five cows each with one of five dosages from 0–2 mg iodine/kg DM; (2) quantify iodine losses during manufacturing of cheese and yogurt from milk with varying iodine concentrations and assess the effect of cellar-ripening; and (3) systematically measure iodine partitioning during heat treatment and skimming of milk. Milk iodine reached a near-steady state after 3 weeks of feeding. Median milk iodine (17–302 μg/l for 0–2 mg iodine/kg DM) increased linearly with feed iodine (R20·96;P< 0·001). At curd separation, 75–84 % of iodine was lost in whey. Dairy iodine increased linearly with milk iodine (semi-hard cheese:R20·95;P< 0·001; fresh cheese and yogurt:R21·00;P< 0·001), and cellar-ripening had no effect. Heat treatment had no significant effect, whereas skimming increased (P< 0·001) milk iodine concentration by only 1–2 μg/l. Mean daily intake of dairy products by Swiss adults is estimated at 213 g, which would contribute 13–52 % of the adults’ RDA for iodine if cow feed is supplemented with 0·5–2 mg iodine/kg DM. Thus, modulation of feed iodine levels can help achieve desirable iodine concentrations in milk and dairy products, and thereby optimise their contribution to human iodine nutrition to avoid both deficiency and excess.


Author(s):  
P.A. Popov ◽  

The presence of residual amounts of antibiotics in milk and dairy products is an actual problem of the dairy industry. Antibiotics reduce the grade of milk and lead to disorders in the technological processes of milk processing into fermented milk extensions, disrupting microbiological processes of fermentation. Milk and dairy products are important foods for all age groups of the population. Milk has a special role in the functional nutrition of children of pre-school and school ages. However, antibiotics used in treating animals, often come in human food, pose a health risk because these compounds and their metabolites can be contained in milk and dairy products if the application rules were not followed. Rapid testing of the presence of residual amounts of antibiotics in raw milk has become a major challenge for farmers and dairy processors. Conventional analytical methods are either too long to perform, too expensive, or do not allow the quantification of antibiotic residues. One alternative method for determining antibiotics is biochip technology, which is fast, easy to implement and cost-effective. The article provides an overview of recent research by domestic and foreign scientists. Differences in biosensors for detecting antibiotic residues in milk have been determined.


2020 ◽  
Vol 54 (3) ◽  
pp. 105-112
Author(s):  
Momčilo Pavlović ◽  
Nedeljko Radlović ◽  
Karolina Berenji ◽  
Bogdan Arsić ◽  
Željko Rokvić

Lactose is a disaccharide found in milk and dairy products. Children and adults with lactose intolerance are unable to tolerate significant amounts of lactose because of an inadequate amount of the enzyme lactase. The condition occurs in three main types: primary, secondary, and primary adult-type hypolactasia. The use of milk in the diet of these individuals may lead to appearance of the irritable bowel syndrome. In persons with lactose intolerance symptoms include diarrhoea, dominated by abdominal colic, loud peristaltic sounds, increased flatulence and meteorism. A diagnosis of lactose intolerance can usually be made with a careful history, elimination of lactose from the diet, lactose tolerance test, hydrogen breath test and genetic testing. In the absence of appropriate tests in patients with suspected primary adult-type hypolactasia, diagnosis can be made as in patients with food allergy. Treatment is based on the restriction of lactose intake with the use of fermented milk products. However, especially for children, if milk and dairy products are eliminated from the diet, it is important to ensure D vitamin and calcium supplementation.


Author(s):  
Ingrida Košičiarová ◽  
Ľudmila Nagyová ◽  
Mária Holienčinová

Milk and dairy products present an important source of essential nutrients which should be a part of human beings nutrition. While the recommended consumption of milk and dairy products is set at the level of 220 kg/person/year, the current studies show that Slovaks consume only 160 kg/person/year. One of the possibilities how to reverse this negative trend is to raise the Slovak consumers awareness of the positive impacts of yoghurts and fermented milk products on their health, as well as to made from them a so‑called trendy food. The aim of the presented paper was to determine the consumer behaviour in the purchase of yoghurts and fermented milk products produced in Slovak Republic. As the research methods were used the methods of survey and structured questionnaire consisting of 16 closed and 1 opened question (total number of respondents was 1,131 randomly selected respondents from all regions of the Slovak Republic). For a deeper analysis of the obtained results, there were set out six assumptions and ten hypotheses, which were tested with the use of Pearson’s chi‑square test, Fisher’s exact test, Cramer’s contingency coefficient and Phi coefficient. The results of the presented paper show, that despite the fact that almost 77 % of respondents said that they prefer in their purchase yoghurts and fermented milk products produced in the Slovak Republic, only 26.4 % of respondents said that they prefer the local producers of these products; exactly 44 % of respondents said that they always look for the information about the content of fat in the yoghurt they buy; more than 33 % said that they buy yoghurts and fermented milk products marked with the Quality Label “Značka kvality SK”; more than 62 % of respondents said that they purchase yoghurts and fermented milk products produced by ecological farming exclusively and rather and exactly 60.1 % of respondents said they prefer the plastic packages of yoghurts and fermented milk products. Up to the question aimed at determining which flavour consumers actually miss on the market, we have to conclude that these flavours are mostly kiwi, muesli with cranberries, chocolate with mint, coconut and banana.


Author(s):  
L. Y. Musiy ◽  
O. Y. Tsisaryk ◽  
I. M. Slyvka

The purpose of the work was to develop recipes and technology of smoothies with high nutritional value by enrichment with fruit and vegetable filler. Experimental studies of organoleptic, physicochemical and microbiological parameters of the strip were conducted in the laboratory of the Department of Milk and Dairy Products Technology. In the first stage, a new product was developed using different ratios of milk and fruit-vegetable base (banana and pumpkin puree in different proportions) and chia seeds. For research, 4 formulations of the strip were developed: control – milk base 75 %, fruit puree – 10 %, pumpkin puree – 10 %, chia seeds – 5 %; sample № 1 – milk base 60 %, fruit puree – 15 %, pumpkin puree – 15 %, chia seeds – 10 %; sample № 2 – milk base 50 %, fruit puree – 20 %, pumpkin puree – 20 %, chia seeds – 10 %; sample № 3 – milk base 40 %, fruit puree – 20 %, pumpkin puree – 20 %, chia seeds – 20 %. Yogurt was used as a milk base. Yogurt was made by tank method. Bacterial preparation of direct application of FD DVS ABY-3 was added to the mixture cooled to a temperature of (37 ± 1) ºС. The increase in titrated and active acidity was monitored during fermentation. The titratable acidity was determined according to GOST 3624-92 “Milk and dairy products. Titrometric methods for determining acidity. Measurements of active acidity were performed using an electronic pH meter “Muttler Toledo MP220”. The vegetable base was prepared as follows: the pumpkin after washing and cleaning was rubbed on a fine grater, then crushed with a blender to obtain a more homogenized mass. Heat treatment of the crushed mass was performed in a water bath at a temperature of +74 ºC for 25 min. The banana was washed, peeled and crushed with a blender to obtain a homogeneous mass. Heat treatment of the crushed mass was performed in a water bath at a temperature of +74 ºC for 25 min. Chia seeds were cleaned of damaged specimens, dust, dirt and other impurities, washed with water for 10 minutes. at a temperature of 20 °C. Chia seeds were mixed with yogurt in a ratio of 1 : 10 at a temperature of 37 °C. Left to swell for 30 min. Then the estimated amount was made to the bulk. Organoleptic and physicochemical parameters according to DSTU 4343:2004 “Yogurts. General technical conditions”. The microbiological parameters of the product were studied according to DSTU IDF 117B:2003 “Yogurt. Determination of the number of characteristic microorganisms. The method of counting colonies at a temperature of 37 °C”. The introduction of chia seeds affected the energy value of the product. The highest energy value is calculated for the sample using 20 % of chia seeds – 110 kcal. The lowest energy value for control is 70.6 kcal, in which the share of milk base prevails. The introduction of chia seeds in the product reduces the number of lactic acid bacteria in the test samples of the smoothies, which in particular correlates with the titrated acidity of the product. When examining the presence of pathogenic microflora in the samples of the strip, it was found that all samples met the requirements for microbiological safety. The number of viable cells of Escherichia coli and bifidobacteria gives the product probiotic properties. According to the results of organoleptic parameters, the best shelf life for the strip is 14 days. All samples of the strip after 14 days had a sour taste and smell and a slight serum. The lowest value of titratable acidity for 14 days of storage was in the sample when using more chia seeds – 20 %. At 21 days of storage in all samples of the strip, the titrated acidity was higher than the allowable value. To expand the range of dairy products with high nutritional value and heroic properties, it is recommended to use in the technology of the strip 50 % milk base (yogurt), 20 % banana puree, 20 % pumpkin puree and 10 % chia seeds.


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