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Among the diverse assortment of dairy products, sour cream occupies a leading position in terms of production. Despite the current economic situation, sour cream production increased by 3.4% compared to the previous year. The lack of raw milk, as well as the increased demand for healthy food products have led to the creation of a new group of sour cream products, which are supplemented with non-dairy ingredients - fortifiers. Due to the components of plant origin, it is possible to adjust the properties of the product, to give it a functional orientation. The authors proposed a method for the production of a sour cream product with the addition of wheat flakes and peach puree. The sour cream product was produced according to the traditional technological scheme. A feature of the technology is the introduction of plant components into the fermented product. The choice of the optimal dosage of wheat flakes and peach puree was carried out in accordance with the combination of the taste of the filler and the product, the indicators of the consistency and color of the sour cream product. The optimal dosages of the introduced components have been selected experimentally. An assessment of the quality indicators of the finished product has been carried out. The water-holding capacity of samples of sour cream products has been studied. By the amount of whey, you can judge the ability of dietary fiber to swell. The smaller the volume of whey, the more the dietary fiber absorbs moisture, which has a positive effect on the shelf life of the product. The viscosity was determined on a vibration viscometer in samples of samples with an undisturbed, damaged and restored clot. It was found that the sour cream product has the best moisture-absorbing ability, a fairly thick consistency, and after mixing it well restores the structure. It has been determined that the use of plant materials has a beneficial effect on the quality of the product.

One of the promising directions in the application of the valuable whey protein cluster is production of the whey protein microparticulate. The aim of the study was modification of the whey protein cluster to obtain the whey protein microparticulate and its use in the sour cream production technology. Cheese whey, whey protein microparticulate and sour cream were used as the objects of the research. The microparticulate production technology included purification of cheese whey from casein and fat, ultrafiltration, thermomechanical treatment. The composition of the objects of the research, their physico-chemical properties were determined according to the Russian standards. During investigations, the bifidogenic properties of the microparticulate, its high antioxidant activity, water- and fat-binding capacities as well as emulsifying capacity were confirmed. The data about an effect of the microparticulate on the physico-chemical and biochemical processes in sour cream production are presented. Addition of the microparticulate stimulated lactose fermentation, influenced sour cream consistency increasing product viscosity and reducing syneresis. The recommended dose of the microparticulate in the sour cream composition was 15%. Quality indicators of sour cream corresponded to the requirements of the normative documentation. Addition of the microparticulate imparted more pronounced aroma to the product. Higher content of lactic acid microorganisms was observed in the finished product compared to the control sample. The prebiotic properties of the microparticulate improved viability of starter cultures during storage. Formation of free fatty acids in the experimental sample during storage was more intensive compared to the control, while fat oxidation was less pronounced. The use of the whey protein microparticulate in sour cream production is characterized by many advantages: it allows achieving an increase in the effectiveness of milk processing, facilitates sustainability, production profitability, improves finished product quality.

The object of research is a sour cream product with the addition of phytosterols in terms of the finished product from 0.141 to 1.710g/100g of product. One of the most problematic places when using phytosterols is their extremely low solubility in water and fats. There are several ways to add phytosterols to foods. Direct application is represented by suspensions of phytosterol nanoparticles. To improve the solubility in water, phytosterols are converted into the form of glycosides. To improve the solubility in fats and oils, phytosterols are converted into fatty acid ethers. An important issue in the development of fermented milk products is the effect of phytosterols on the homogeneity of the system, the fermentation process, the final properties of the product. During the study, the introduction of pre-esterified phytosterols as a substitute for milk fat with a melting point of 32–34°C to milk-fat mixtures. Milk-fat mixtures of various compositions were fermented with the study of acidity during fermentation. To study the properties of the system, milk fat was replaced by vegetable fat by 25, 50, and 75%. The content of lactic acid bacteria was determined for the final product and the organoleptic parameters of the product were compared. The results show that when fermenting for 14hours, the required acidity parameters of pH 4.2 to 4.6, titratable acidity of 76 to 79°T were achieved at 12 hours. Phytosterols did not harm the fermentation rate, and after the process did not worsen the taste and appearance of the product. This provides the opportunity to obtain a high-quality sour cream product with additional properties. The process of fermentation of sour cream products with phytosterols corresponds to the parameters of the standard sour cream product and sour cream. This provides advantages such as the ability to integrate a new product into the sour cream and sour cream production system without significant changes in technology and equipment.

The sensory properties and flavor of sour cream are important factors that influence consumer acceptability. The present study aimed to isolate lactic acid bacteria with excellent diacetyl production ability and to optimize the fermentation conditions for sour cream manufacture. Lactococcus lactis ssp. cremoris was isolated as a lactic acid bacterium derived from raw milk. This strain showed the greatest diacetyl production among other strains and was named LRCC5306. Various culture conditions were optimized to improve the diacetyl production of LRCC5306. The highest diacetyl production was found to be at 105.04±2.06 mg/L, when 0.2% citric acid and 0.001% Fe2+ were added and cultured at 20°C for 15 h. Based on the optimal cultivation conditions, sour cream was manufactured using LRCC5306, with a viable count of 1.04×108 CFU/g and a diacetyl concentration of 106.56±1.53 mg/g. The electronic tongue system was used to compare the sensory properties of the sour cream; the fermented product exhibited sweetness and saltiness which was similar to that of an imported commercial product, but with slightly reduced bitterness and a significantly greater degree of sour taste. Therefore, our study shows that if cream is fermented using the LRCC5306, it is possible to produce sour cream with greatly improved sensory attractiveness, resulting in increased acceptance by consumers. Since this sour cream has a higher viable count of lactic acid bacteria, it is also anticipated that it will have a better probiotic effect.

Fucoidan extracted from seaweed, particularly Sargassum angustifolium, is considered asnatural antioxidant agent.The present survey was aimed to assessthe effect of fucoidan extracted from S. angustifolium on oxidative stability of butter produced from sour cream. Fucoidan was extracted from S. angustifolium samples. Prepared fucoidan powdered were weighted in 0.05, 0.1, 0.3, 0.5 percent and added to butter samples. All samples were then kept in the refrigerator up to 60 days. The DPPH radical scavenging effects of extracted fucoidan and also acidic and peroxide values of butter samples were evaluated. Fucoidan (100 µg/mL) had the uppermost DPPH radical scavenging effect (56.46±5.27%), while that of 12.50 µg/mL had the lowermost (34.75±3.26%). Acidic value of butter samples had been increased during the storage period (P

It is known that one of the main causes of spoilage of fats (in particular vegetable fats), as well as products made with their use, is an increase in acid and peroxide numbers. Physicochemical indicators have a significant impact not only on the quality and organoleptic characteristics of the product, but also on its safety. For this purpose, the dependence of the indicators of acid and peroxide numbers of the created blend of vegetable oils in the technologies of milk-containing products during storage has been investigated. The object of research is experimental samples of a three-component blend of vegetable oils and milk fat isolated from milk-containing curd paste and milk-containing sour cream sauce. The subject of research is the dynamics of the growth of acid and peroxide numbers of samples and changes in their organoleptic quality indicators. The obtained data on the kinetics of oxidation of a blend of vegetable oils indicate that the increase in acid and peroxide numbers during the studied shelf life does not differ in intensity. The average threshold for an increase in acid and peroxide numbers is insignificant and amounts to 0.02–0.03mgKOH/h and 0.2–0.21mmol1/2O/kg for 5days. In accordance with the obtained results of the kinetics of oxidation of the released fat of milk-containing curd paste, there is a slight increase in acid and peroxide numbers, namely: at the end of 7days – up to 0.3mgKOH/h and 1.9mmol1/2O/kg, respectively, and in at the end of 10days– up to 0.32mgKOH/h and 2.3mmol1/2O/kg. Based on the obtained results of the kinetics of oxidation of the released fat from the milk-containing sour cream sauce, there is a tendency to a gradual increase in the acid and peroxide numbers with an increase in the oxidation time. It is noted that the maximum values of acidic – 0.3mgKOH/h and peroxide numbers – 2.2mmol1/2O/kg at the end of the shelf life of 21days are reached. According to the results obtained for the organoleptic evaluation of experimental samples of the blend and the released fat from milk-containing products, no significant changes were found during the studied shelf life.

The aim of the study is to assess the content of trans-fatty acids (TFA) present in the sour cream produced in the RA and conduct a dietary exposure assessment. Data on sour cream consumption has been gathered through food frequency questionnaire (FFQ). TFA contents in sour cream samples were determined using the method of gas chromatography. Daily intake of TFA through sour cream consumption has been estimated. TFA daily intake (E %) accounted for 0.03 %, 0.185 % and 0.457 % of total energy intake (kcal) for sour cream consumption Cluster 1, 2 and 3, respectively. It was discovered that TFA daily intake through sour cream consumption does not exceed the recommended threshold value (≤ 1 E %).

The dynamics of changes in organoleptic parameters titrated acidity and moistureretaining capacity of sour cream with a mass fraction of fat of 10% based on normalized cream mixtures of different component composition during storage at a standard temperature (4±2)oC for 40 days was studied. The influence of buttermilk obtained by a continuous method of churning cream in the composition of normalized cream mixtures on the quality indicators and consumer properties of sour cream with a low fat content is determined.

Background. Goat milk differs from cow's milk in terms of higher digestibility, expressive alkalinity, higher buffering capacity and special nutritional properties. Among the wide range of dairy products the leading place is occupied by butter. Research aimed at creating its varieties with moderate calories and high physiological value with attractive organoleptic characteristics that meet the modern concept of healthynutrition is relevant. High-quality butter from goat's milk can be produced only with the use of biotechnological approaches, aiming at enhancing sensorial parameters and increasing the content of fatty acid components. Objective. We aimed to develop the technology of goat's sour cream butter production. Methods. The technological stages of making sour cream butter from goat's milk were developed. Determination of physical, chemical and microbiological parameters of the finished product was carried out in accordance with generally accepted techniques. Results. The developed technology involves fermenting goat's milk sour cream with a bacterial preparation, activated in whey infusions of medicinal herbs. We used the bacterial preparation "KVM-P" containing Lactococcus lactis ssp. lactis biovar. diacetilactis, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, and made ex tempore whey infusions of medicinal herbs: nettle (Urtіca dіoіca), mint (Mentha aquatica) and amaranth (Amaranthus cruentus). Activation of the bacterial preparation "KVM-P" in the infusion of medicinal herbs has reduced the duration of its dissolution to 20–30 minutes instead of 3–4 hours (as envisaged by traditional technology). Enrichment of butter with the components of herbal whey infusions increased the content of dry milk residue of the product, which led to increase in butter yield from every 100 kg of cream up to 0.8 kg. Produced products were analyzed by acid number of fatty phase, content of low molecular weight fatty acids lactic and lactobacillales count. The content of lactobacilli (CFU/g) in the experimental batches of butter was 1.3–2.5 times higher compared to the control sample. The slightly lower number of microbiota in the experimental batch of butter, produced using an infusion of mint leaves, is due to its bacteriostatic effect on microorganisms. During storage of the experimental batches of butter for 30 days at the temperature of 4 °C, the peroxide value was 0.3 mmol/kg ½ O. In control samples of the product, this rate was 2 mmol/kg ½ O, which indicates the increased resistance of the experimental batches of butter to oxidation of fat during storage. Organoleptic parameters of the experimental samples of butter met the requirements of state standards. The taste and smell of goat’s sour cream butter were weak. Conclusions. We developed technology of production of sour cream butter from goat's milk which is based on the use of activated bacterial preparation of herbal whey infusions. This technology significantly reduces the taste and smell of goat fat and prolongs the shelf life.

Modification of dairy products’ fat composition or replacement by other fats are common practices in the industry. Products in which milkfat is partially or wholly substituted by vegetable fats are defined as dairy analogues. This study delivers gap-filling information about sour cream analogues in nutritional aspects, focusing on the fat-related attributes. Analogue sour creams contained 29.6% less saturated fatty acids, 88.4% less cholesterol and 88.7% more mono- and poly-unsaturated fatty acids than the sour creams. Trans fatty acids were present in both products, which could not be linked to artificial hydrogenation in either case. Digestibility of the examined samples might be different, as sour creams had more short and medium chain fatty acids than the analogues. Overall, sour cream analogues, besides serving as an alternative to sour cream, have particular advantages based on their nutritional values.

Lactic acid bacteria (LAB) have an important role in the food industry because they are used in the production of fermented fo ds. To use these microorganisms in the food industry, it is necessary to obtain a high amount of biomass. One of the most important environmental factors in the growth of LAB is pH. Most of LAB species can tolerate a pH below 5.0, however, a suboptimal pH is expected to limit LAB growth. For this reason, the LAB strains Leuconostoc mesenteroides 67-1, Lactobacillus plantarum 60-1, and Streptococcus infantarius 46-3, isolated from sour cream, were grown in culture media under four different intial pH values to determine their optimal growth pH. Growth was assesed via colony-forming unit (CFU/ml) determination. We found that the growth of each LAB was affected by culture medium pH. We determined that the setpoints of pH for Leuconostoc mesenteroides 67-1, Streptococcus infantarius 46-3, and Lactobacillus plantarum 60-1 were of 4.5 (± 0.5), 5.5 (± 0.5), and 6.0 (± 0.5), respectively. We thus conclude that the growth of these LAB strains is pH-dependent (p < 0.05).

Since antiquity people have known about the health benefits of fermented milk products. These products are obtained by lactic acid fermentation using various microorganisms, but primarily Lactobacillus spp. The number of varieties of fermented milk products is large. The most famous are yogurt, kefir, lapper milk, baked yogurt, sour cream. Yogurt is made using sourdough includingStreptococcus thermophilusandLactobacillus bulgaricus. Numerous positive effects of yoghurts are shown, including the antibacterial effect against many pathogenic microorganisms. Yogurt, like other fermented milk products, have a reduced lactose content compared to whole milk, which allows people with lactase deficiency to consume this product. In addition, the protein of fermented milk products is more accessible to enzymes of the gastrointestinal tract and is easier to digest. The hypocholesterolemic effect of yogurt is also shown. Fermented milk products, including yogurt, are recommended for baby food. In particular, the efficacy of drinking yogurt enriched with prebiotics and probiotics is shown for both healthy children and children with functional disorders of the gastrointestinal tract, disorders of the intestinal microflora, whose who is sick often and long, as well as in the acute period of acute respiratory viral infections and at the convalescence stage. Thus, the ideas about the importance of fermented milk products for health and longevity, expressed more than 100 years ago, today have a solid scientific basis and research in this direction continues.

Probiotic products, in particular bifidus products, are becoming increasingly popular, because of their potential health benefits. Today, there are over 70 bifidus-containing products produced worldwide, including sour cream, buttermilk, yogurt, powdered milk, cookies, and frozen desserts. More than 53 different types of milk products that contain Bifidobacterium spp. are marketed in Japan. The species of Bifidobacterium commonly found in fermented milk and yogurt products include Bif. bifidum, Bif. breve, and Bif. longum. A number of health benefits have been claimed for Bifidobacterium. In order to realize health benefits, the suggested level for Bifidobacterium is >106 viable cells per gram of a product. However, a number of factors have been claimed to affect the viability of Bifidobacterium in fermented milks, including inhibitory substances such as lactic acid produced during fermentation and cold storage, strains used, interaction between species present, final acidity, availability of nutrients, growth promoters and inhibitors, dissolved oxygen, and oxygen permeation through the package. Proper strain selection should be carried out before using these strains in commercial products. The survival and viability of Bifidobacterium could be improved by incorporating peptides or amino acids in fermented milks.

Spore formers are common spoilage-causing microorganisms in dairy products; however, their modes of spoilage (proteolysis, lipolysis, etc.) have not been described in detail for cultured dairy products such as sour cream and yogurt. The objective of the present study was to test the ability of spore-forming strains isolated from dairy environments for their spoilage-causing activities at typical sour cream (24°C) and yogurt (42°C) fermentation temperatures. A total of 25 spore-forming strains were isolated from different sources, including raw milk, pasteurizer balance tank, biofilms formed on heat exchangers, and milk powder. These strains were tested for proteolytic and lipolytic activities and for their ability to degrade phospholipids, common stabilizers (starch, gelatin, xanthan gum, pectin), and exopolysaccharides (EPS) at sour cream and yogurt fermentation temperatures. A higher percentage of positive strains was observed for selected activities at yogurt fermentation temperature compared with sour cream fermentation temperature. Identified proteolytic spore-forming strains, based on a skim milk agar method, were subsequently quantified for their level of proteolysis using non-casein nitrogen (NCN) content and sodium dodecyl sulfate-PAGE (SDS-PAGE). The proteolytic strains that showed the highest levels of proteolysis (highest percentages of NCN content) at 24°C were Bacillus mojavensis BC, Bacillus cereus DBC, Bacillus subtilis DBC, B. mojavensis DBC1, and Paenibacillus polymyxa DBC1. At 42°C the strains with the highest levels of proteolysis (highest percentages of NCN content) were B. subtilis DBC, B. mojavensis BC, B. mojavensis DBC1, B. cereus DBC, and Bacillus licheniformis DBC6. Results of SDS-PAGE demonstrated that proteolytic strains had primarily hydrolyzed β- and κ-CN. A viscometric method was used to evaluate the susceptibility of exopolysaccharides (EPS) to degradation by selected spore formers. This method helped to determine that EPS produced by commercial yogurt and sour cream cultures is susceptible to degradation by spore formers present in dairy environments.

Cross-sectional studies concerning the contamination of milk and milk products by perfluoroalkyl substances (PFASs) are presented and the extent of contamination that may occur in food samples, collected in Poland in 2016 is evaluated; not only milk, cottage cheese, natural yoghurt and butter but also previously untested foods, including kefir, sour cream and Camembert-type cheese. Levels of 7 perfluoroalkyl carboxylic acids (PFCAs) and 3 perfluoroalkane sulfonates (PFSAs) were analysed using the QuEChERS extraction method followed by micro-HPLC-MS/MS. All PFASs were detected with an RSD of lower than 10%. The most commonly detected was perfluorooctanoic acid, followed by perfluorobutanoic acid and perfluorohexane sulfonate, on par with perfluorooctane sulfonate. The largest contributor to the total PFAS concentration in the investigated food samples was perfluorobutanoic acid, and its summary concentration within the group was estimated to be 13.34 ng g−1. The results for 43.4% of samples analysed were greater than LOQ (limit of quantification).

The consumption of sour cream in Russia is growing every year. According to the data obtained from the Federal State Statistics Service and the Federal Customs Service, the production volume of sour cream in Russia in-creased by 5.55% in 2014–2018. However, the production of sour cream remains lower than its consumption. The solu-tion may be in production of sour cream products, which will make it possible to satisfy the demand, while non-dairy components will make the products functional. The authors propose to use fiber as a functional ingredient. The present research featured sour cream, a sour cream product with a 20% fat content, and such components of plant origin as fiber of Vitaminaya Polyana brand, rye fiber, wheat fiber, wheat fiber with licorice, and carrot puree. The authors selected the most optimal formula and composition for sour cream products. Standard research methods were used to study the sensory, physical, chemical, and microbiological indicators of the dairy products. The experiment revealed that 2.5% of fiber in the composition of sour cream product improved its consumer properties while preserving the original taste and smell of the product. Carrot puree was used as a color correcting and flavoring component. Its dosage was determined empirically. The sample of sour cream product with a carrot puree fraction of 5.0% received the highest overall rating. Fortified sourcream was obtained according to the technological scheme of production of sour cream with the addition of non-dairy components at the standardizing stage. The samples of sour cream product with fiber were found to promptly restore its structure and were characterized by an increased viscosity index compared with the control sample. The research resulted in a sour cream product with wheat fiber, licorice, and carrot puree. Samples of sour cream products and sour cream were stored for 20 days at a temperature of 6 ± 2 °C. The study established the optimal shelf life as 14 days.

The aim of the present study was to examine the fatty acid composition and healthy lipids indices in raw milk and dairy products, covering the main stages of production. The fresh cheese, butter, sour cream, and ultra-high temperature treated milk, representing differences in technological approach were chosen for the study. Fatty acids methyl esters were quantified using a gas chromatograph equipped with flame ionization detector and a capillary column SP-2560. No significant influence of the technological process has been identified. The concentrations and profile of fatty acids and healthy lipids indices in final product fat were primarily dependent on the content of the raw milk or cream. The significant difference (P

Maillard reactions occur in dairy products during heat treatment. Furfuryl alcohol (FA) may be found in dairy products as a result of Maillard reactions. The recent posting in California Proposition 65 indicates that FA may be carcinogenic, and for this reason it is crucial to accurately measure FA concentrations in dairy products. The objective of this study was to identify an extraction and quantitation method for FA from dairy products and to determine FA concentrations in milk, dairy powders, and cultured dairy products. Solvent-assisted flavor extraction, solid-phase microextraction, stir bar sorptive extraction with gas chromatography-mass spectrometry and triple quadrupole mass spectrometry were compared for recovery of FA. Internal standards for the quantitation of FA (2-methyl-3-heptanone, furfuryl-d5 alcohol, 2,5-dimethylphenol, 5-methyl-2-furfuryl alcohol, and 5-methyl furfural) were also compared. Subsequently, fluid milk [high temperature, short time (HTST) and ultrapasteurized], whey protein isolates (3 mo–4 yr), whey protein concentrates (3 mo–4 yr), whole milk powders (1 yr), high and low heat skim milk powders (SMP; 0–8 yr), milk protein isolates (3 mo–3 yr), milk protein concentrates (3 mo–3 yr), Cheddar cheese (mild, medium, sharp, and extra sharp), mozzarella cheese (whole and part skim), cottage cheese (nonfat, low fat, and full fat), sour cream (nonfat, low fat, and full fat), traditional yogurt (nonfat, low fat, and full fat), and Greek-style yogurt (nonfat; n = 139 products total) were evaluated. Furfuryl alcohol was extracted from products by headspace solid-phase microextraction followed by gas chromatography-triple quadrupole mass spectrometry using a ZB-5ms column (30 m × 0.25 mm × 0.25 µm; Phenomenex Inc., Torrance, CA). Furfuryl-d5 alcohol was used as an internal standard. Each food was extracted in triplicate. Ultrapasteurized milks had higher levels of FA than HTST milks (122.3 vs. 7.350 µg/kg). Furfuryl alcohol concentrations ranged from 0.634 to 26.55 µg/kg in whey protein isolates, 2.251 to 56.19 µg/kg in whey protein concentrates, 11.99 to 121.9 µg/kg in milk protein isolates, and 8.312 to 49.71 µg/kg in milk protein concentrates, and concentrations increased with powder storage. High heat SMP had higher concentrations of FA than low heat SMP (11.8 vs. 1.36 µg/kg) and concentrations increased with storage time. Concentrations of FA in Cheddar and mozzarella cheese ranged from 2.361 to 110.5 µg/kg and were higher than FA concentrations in cottage cheese or sour cream (0.049–1.017 µg/kg). These results suggest that FA is present at higher levels in dairy products that have been subjected to higher temperatures or have been stored longer. Sour cream and cottage cheese had lower levels of FA. Compared with other studies on food products with reported levels of FA, such as coffee (200–400 µg/g), dairy products have very low levels of FA.

Background The newly created associations of lactic acid bacteria (LAB) isolated from Armenian dairy products (yoghurt, sour cream and different varieties of cheese), as well as from the gastrointestinal tract of honeybees were screened according to their antifungal and antibacterial activity. Results LAB strains were mixed at equal proportions (1:1) according to mathematical planning of experiments. Antifungal and antibacterial effects of different combinations (associations) were determined in different media, employing well-diffusion and total diffusion into agar methods. A number of fungal and bacterial test-organisms, including pathogenic ones, were used. Pure LAB strain cultures were used as a control. The antifungal effect of the most active strain Lactobacillus rhamnosus MDC 9661 in the associations with other LAB strains was partly decreased. At the same time, some mixed LAB cultures in DeMan, Rogosa and Sharpe (MRS) medium demonstrated significant antibacterial activity against wide spectra of test-organisms only in the case of simultaneous cultivation of LAB strains. On the other hand, in the case of different LAB strains cultivated in MRS with 24-h time break between mix formations by different strains, no inhibitory activity was revealed. But the inhibitory effect of many LAB associations against test-organisms was significantly increased in the case of separated cultivation in milk. Conclusion The inhibitory effect of mixed LAB associations showed stronger dependence on the cultivation media and on the duration of cultivation with respect to each other. The co-cultivation of some strains, like L. rhamnosus MDC 9661, could lead to changed antagonistic activity. Consequently, the results are significant for creation and further investigation of LAB associations, as effective probiotics, and for their probable application in the production of antimicrobial preparations.

Postprandial lipemia is a risk factor for cardiovascular disease. Dairy products differ in nutrient content and food matrix, and little is known about how different dairy products affect postprandial triglyceride (TG) concentrations. We investigated the effect of meals with similar amounts of fat from different dairy products on postprandial TG concentrations over 6 h in healthy adults. A randomized controlled cross-over study was performed on 47 subjects (30% men), with median (25th–75th percentile) age of 32 (25–46) y and body mass index of 23.6 (21.0–25.8) kg/m2. Meals included 1 of butter, cheese, whipped cream, or sour cream, corresponding to 45 g of fat (approximately 60 energy%). Serum concentrations of TGs (primary outcome), and total cholesterol (TC), low density lipoprotein cholesterol (LDL cholesterol), high density lipoprotein cholesterol (HDL cholesterol), insulin, glucose, non-esterified fatty acids, and plasma glucose-dependent insulinotropic polypeptide (secondary outcomes) were measured before the meal and 2, 4, and 6 h postprandially. Incremental AUC (iAUC) was calculated for the responses, and data were analyzed using a linear mixed model. Sour cream induced a 61% larger TG-iAUC0–6 h compared to whipped cream (P

International audience; Background and Objective: Adulteration of dairy products by substitution of milk fat by vegetable oil is common in the Eurasian Economic Union. The objective of the paper is to investigate the potential adulteration of the fat and to test the more convenient methods of detection, i.e., determination of fatty acids or sterols profiles in commercial butter and cream. Materials and Methods: Ten samples of commercial butter and 8 samples of commercial sour cream were collected on the national market of Kazakhstan. The analyses involved the original sour cream and butter without any modification (deep-freezing) and were achieved within the shelf-life period. The fatty acid composition was analyzed by GS-FID and Sterol fractions were analyzed by GS-MS. Statistical analysis was achieved by principal components analysis (PCA), Pearson types, Kruskal-Wallis test. Results: Sixty percent of the butter samples contained traces of phytosterols and one sample contained up to 78% $-sitosterol. In sour cream samples, only three contained 100% cholesterol while two contained more than 60% sitosterol. The detection of fat adulteration by analyzing the fatty acids patterns is convenient in case of massive substitution of milk fat, but a discrete substitution does not modify the fatty acids profiles leading to misinterpretation. Conclusion: The results exhort to give preference to sterol profile determination as an official method to detect fat adulteration in dairy products. This is even more important as the current standard used in Central Asia based on some fatty acids ratios can lead to incorrect conclusions.

This study aimed to compare the effect of different ratios of Streptococcus thermophilus to Lactobacillus bulgaricus (3 : 1, 1 : 1, and 1 : 3) under the various stressful temperatures (37 and 45°C) on the fatty acid profiles quality of Kermanshahi roghan (yogurt by-product) and sour cream to obtain a formula for producing a kind of animal fat healthier than milk and cream. Stresses such as fermentation play an important role in bacterial behavior and consequently in food quality. Our findings presented a significant difference between roghan and sour cream fatty acid levels only at 37°C. Furthermore, starter culture 3 : 1 was the best starter for producing products with a higher quality of fatty acid profile at 37°C, and a 1 : 1 S. thermophilus to L. bulgaricus ratio was optimal at 45°C. It seems that bacteria adapt to harsh growth conditions by changing the fatty acid profiles, and these changes warrant consideration in the production of a kind of animal fat with the best fatty acid profiles. In conclusion, the roghan fatty acid profile is more suitable than sour cream only at 37°C.

Background Fermented cream is a common and widely used dairy product throughout the world. The structure of sour cream with a low (10 to 15%) fat content is determined by the acid gel of milk proteins, while that of sour cream with a high (≥30%) fat content is determined by the gel formed by fat globules coated with protein. Sour cream with a fat content of about 20% has an intermediate gel structure, which is not characterized with high viscosity. To increase the viscosity of the product, as well as to prevent the separation of whey during storage, thickeners and stabilizers (gelatin, various types of starch, etc.) are added. As these decrease the sensorial characteristics of products, new thickeners (elamin, citrus pectin, flax seed flour, banana puree, and fromase milk-clotting enzyme preparation) are used instead. Methods Sour cream was made by separating whole cow's milk, normalization, homogenization, pasteurization and fermenting by mesophilic lactic acid bacteria. Then thickeners were introduced to the clot: elamin, dry banana, flax seed flour in mass fractions of 0.01%, 0.03% and 0.05%, as well as fromase preparation in the same amount. A control batch of sour cream was made without the use of additives. The ripening process lasted from 8 to 9 hours to obtain a dense consistency. The viscosity of the samples was determined using a rotational viscometer, consisting of two coaxial brass cylinders, between which the test liquid was located. The effective viscosity and its dependence on the shear rate γ in research samples as non-Newtonian fluids were determined. Results Sour cream is characterized by the presence of a structure quickly destroyed by external forces at shear rates greater than 10 s-1, so exceeding the given value in the production of sour cream is not rational. The dependences of the rheological parameters of sour cream on the content of the additives elamin, flour from flax seeds and dry banana puree, used as thickeners, showed that the greatest strength of intermolecular bonds and the stability of the studied mixtures can be expected with a share of additives ranging from 0.01 to 0.03% (by mass). At the same time, when the said share exceeds 0.05%, the structure of sour cream is weakened - this is especially characteristic in the case of adding dry banana. Conclusions The research showed that natural thickeners can be chosen to improve the rheological parameters of low fat sour cream without deteriorating its sensorial characteristics. This leads to the conclusion that the studied thickeners can improve the viscosity of sour cream with a low fat content - and dry banana is the best of those studied. Correspondingly, viscous properties are among the principal ones which define customers' perceptions of the product, its low fat content being a possible spoiler of sensorial traits.

Preveli cheese is Croatian artisanal dried acid-coagulated cheese. The aim of this paper was to study its physicochemical composition and microbiological properties, as well as physicochemical composition and hygienic quality of cheese milk. The results could be used for the improvement of Preveli cheese quality and for getting a mark of Protected Geographical Indication (PGI). The production of 35 batches of Preveli cheese was observed at 18 family farmsteads. Research showed that hygienic quality of milk was partially satisfying, which means that 51.42% and 17.14% of milk samples had total bacterial count and somatic cell counts above the threshold value (>300,00 and >400,000∙mL-1, respectively). According to the content of total solids, Preveli cheese belongs to the group of soft cheeses, while according to the content of fat in total solids it can be categorized as a fat cheese. Due to the non-standardized technological processes, mainly during skimming the milk fat, salting and drying, results of analysis showed notable variability in the physicochemical composition of the Preveli cheese and sour cream. The presence of yeast and moulds were detected in 22.86% of cheese samples as well as coagulase positive staphylococci in 11.43% of cheese samples, which indicated the need of improving the hygiene of the manufacturing processes., Cilj ovog rada bio je utvrditi fizikalno-kemijski sastav i mikrobiološke karakteristike prevelog sira, hrvatskog sušenog kiselinskog sira, te fizikalno-kemijski sastav i higijensku kvalitetu mlijeka za sirenje. Za potrebe istraživanja proizvedeno je 35 uzoraka prevelog sira prikupljenih na 18 obiteljskih gospodarstava. Istraživanja su pokazala da je higijenska kvaliteta mlijeka djelomično zadovoljavajuća, odnosno da 51,42% i 17,14% uzoraka mlijeka imaju ukupan broj bakterija i broj somatskih stanica iznad dopuštenih vrijednosti (> 300,00 i > 400,000∙mL-1). Prema ukupnom sadržaju suhe tvari, preveli sir pripada skupini mekih sireva, a prema sadržaju masti u suhoj tvari može se klasificirati kao masni sir. Zbog nestandardiziranih tehnoloških postupaka, uglavnom tijekom obiranja mliječne masti (vrhnja), soljenja i sušenja, rezultati analize pokazali su značajnu varijabilnost u fizikalno-kemijskom sastavu prevelog sira i vrhnja. Prisutnost kvasaca i plijesni te bakterije Staphylococcus aureus utvrđena je u 22,86% i 11,43% uzoraka sira, što ukazuje na potrebu poboljšanja i održavanja higijenskih uvjeta tijekom procesa proizvodnje.

Lowering of greening formed from oxidized chlorogenic acid (CGA) and amino groups, and favoured at alkaline pH, was investigated using acidic ingredients (sour cream, buttermilk, yoghurt, and honey) in sunflower butter cookies. Cookies with maple syrup added were used as a positive control. Changes in greening intensity, greening reactants (total phenols, CGA, protein), antioxidant capacity, tryptophan and Schiff base fluorescence were measured. Percentage greening, pH and aw of cookies followed the same order: maple syrup > sour cream ≥ buttermilk > yoghurt > honey. pH was positively correlated with greening intensity (r = 0.77) and negatively correlated with CGA (r = −0.96). Total phenolic content, antioxidant capacity, tryptophan and Schiff bases were similar among cookies. The results suggest it is possible to decrease greening by minimizing storage time and using acidic ingredients. Minimal greening with acidic ingredients can extend the application of sunflower butter as a baking ingredient without loss of free radical-scavenging capacity, or higher protein oxidation.

Butter fat undergoes oxidation process, causing a sequence of unfavorable steps changes causing itsdeterioration with inferior sensory properties and decrease in nutritious value. Several factors affect the quality andoxidation process such as storage conditions, acidity of cream and the type of milk fat. The aim of this study was toassess the changes in quality characteristics and oxidation process in both cow`s and buffaloe`s butter made from sweetor sour cream stored at 5 oC compared with traditionally stored at -20 oC. It was found that butter stored at 5 oCincreased the oxidation process expressed as peroxide value, thiobarbaturic acid reactive substances, as well as raisedthe fat acidity and refractive index with higher decreasing rate for iodine values. Butter made from sour creamaccelerated the oxidation process and decreased its quality properties than that made from sweet cream. Generally,cow`s butter had higher oxidation rate than that of buffaloe`s butter.

For forming structural-mechanical properties of sour milk pastes and guaranteeing their stability at storage, it is promising to use non-fried buckwheat in their recipes that allows to raise the food value of products additionally. The aim of the researches was the study of features of the condition of moisture of sour milk pastes, based on sour cream with introducing non-fried buckwheat in the amount 5,0 % of the mixture mass. A sample with modified starch Е 1410 was taken as a control in the amount 1,3 %. The study of the moisture condition was realized by the thermogravimetric method using a derivatograph Q-1500D (Paulik-Erdey) (Hungry). It was established, that the content of adsorptive moisture of the sour milk paste was 34,0 %, whereas in the control – 34,5 %, that confirm the effectiveness of using non-fried buckwheat as a moisture-binding component. Such properties of non-fried buckwheat may be explained by the presence of starch compounds and easily accessible protein in its composition, able to hydration in the process of preparation of a component and to keeping moisture at further storage of a product.

Summary The viscoelastic properties provide guidelines to help give meaning to the observations on food products, to relate them to the way in which their structures behave, and to predict or modify their properties. This study analyses the incidence of varying the initial fat content of goat milk on the rheological properties of prepared sour cream. Storage (G′) and loss modulus (G″), as well as complex viscosity (η*) and loss factor values (tan δ), were determined at different initial fat contents in goat milk (3.75%, 4.00% and 4.25%). The experimental data were adapted to Maxwell model. All the prepared samples of sour cream meet national and international microbiological standards, and the initial fat content of goat milk influenced the viscoelastic behaviour of sour cream. Structures with prevalent elastic (G′) behaviour were found, and the product that was prepared from goat milk with 4.00% fat content showed the highest elastic modules. This sour cream exhibited higher firmness and better adherence when compared to the samples that were obtained from 3.75% and 4.25% fat-content milk. This sample also exhibited the lowest tangent of the phase angle. Sour cream that was prepared from milk with higher fat content (4.00% and 4.25%) exhibited a semi-solid behaviour along the entire temperature range that was studied. On the contrary, rheological properties of sour cream from 3.75% fat-content milk tend to increase at temperatures above 333.15 K. The viscoelastic behaviour of sour cream was successfully explained under Maxwell model, while data from dynamic viscosity (η′) were adapted to Arrhenius model. Microstructure analysis to the sample considered as the best (from milk with 4.00% of initial fat content) showed that the protein network presented a rough, open surface with aggregates and wide spaces.

The use of ultra-filtered lactic acid whey retentate was investigated for the making of sour cream. The utilization of lactic acid whey is limited due to its special properties, so the logical utilization way is to use it in fermented products. First, we concentrated lactic acid whey collected from cottage cheese making by ultrafiltration (UF), then UF Whey Retentate (UFWR) was added (by 2, 5, and 10%) into fat standardized cream for sour cream making. We investigated the texture and sensory properties of the sour cream samples compared with the industrial products. Generally, we can state that the use of small portion of UF whey retentate did not result noticeable changes and did not reduce the sensory value of sour creams. Higher UF whey retentate addition improved some texture properties of experimental samples, but the summarized evaluation of UFWR addition was not unequivocal. Control samples showed better results. Based on our results, the sample, which contained 5% UF whey retentate, had good texture and acceptable sensory properties. Furthermore, more than 5% UF lactic acid whey retentate (coming from our own ultrafiltration process) resulted remarkably worse sensory properties than the other samples. Further investigation is needed to find the optimal composition and sensory properties of UFWR. Furthermore, we have to perform technological investigation to reach a higher concentration factor using pre-treatment of whey and to avoid the precipitation of whey proteins during the high temperature pasteurization of cream, cream mixed with UFWR or diafiltered whey retentate. We guess that the use of one-stage diafiltration would already decrease the unfavourable sensory properties of lactic acid whey retentate.

Organochlorine insecticides residues (α–HCH, β-HCH, Lindane, HCB, Aldrin, Heptachlor, Chlordane, total DDT, Endrin and Methoxychlor) were analyzed in 75 samples of raw milk, sour cream and cooking butter-collected from Beni-Suef Governorate- using gas chromatography with electron capture detector (GC-ECD). The results indicated that all the examined samples were accepted except three butter samples showed residue levels exceeded the Maximum Residues Levels (MRLs).

The method of solution of the problem of polyunsaturated fatty acids (PUFA) lack in milk products is offered in the work. It is offered to create the milk-containing products (sour cream product) with adjusted fatty acid composition. The possibility of replacement of the mass part of milk fat (50 %) by the blend of natural vegetable oils was studied. For the solution of this problem the program within MatLab mathematical package was elaborated. The recommended fatty acids (FA) ratio [3] is selected as optimization parameter. The optimized blend was created using the elaborated program. The data, received by mathematical calculations, were experimentally proved using the method of gas-liquid chromatography [7]. On the based of the results, received at the studies, it can be stated, that 50 % replacement of mass part of fat (m.p.f.) in milk products (sour cream product) by elaborated blend, allows partially adjust its FA composition.

Peel Plate™ EC is a low-profile plastic, 47 mm culture dish with an adhesive top that contains a dried medium with Gram-negative selective agents and with enzyme substrate indicators for β-galactosidase (coliform) and β-glucuronidase (Escherichia coli). The method provides a conventional quantitative coliform (red) and E. coli (blue/purple/black) count with simple rehydration and incubation for 24 ± 2 h at 35 ± 1°C, while providing a total coliform result, sum of E. coli, and coliform without color differential in dairy products at 32 ± 1°C for 24 ± 2 h. Dairy matrixes claimed and supported with total coliform data are whole milk, skim milk, chocolate milk (2% fat), heavy cream (35% fat), pasteurized whole goat milk, ultra-high-temperature pasteurized milk, powdered milk, lactose-reduced milk, strawberry milk, shredded cheddar cheese, raw cow milk, raw goat milk, raw sheep milk, sour cream, condensed milk, eggnog, vanilla ice cream, condensed whey, yogurt, and cottage cheese. Matrixes claimed for E. coli and total coliform detection are raw ground beef, mixed cellulose 0.45 μm filtered bottled water, environmental sponge of stainless steel, raw ground turkey, dry dog food, liquid whole pasteurized eggs, milk chocolate, leafy green (mixed greens) rinse/flume water, irrigation water, poultry carcass rinse, and large animal carcass sponge. The method has been independently evaluated for total coliform in whole milk, skim milk, chocolate milk, and heavy cream. The method was also independently evaluated for E. coli and coliform in ground beef, filtered bottled water, and sponge rinse from stainless steel surfaces. In inclusivity and exclusivity studies, the method detected 57 of 58 different strains of coliform and E. coli at 32 ± 1°C and 35 ± 1°C in and excluded 31 of 32 different noncoliform strains consisting of Gram-negative and Gram-positive bacteria. In the matrix study, each matrix was assessed separately at each contamination level in comparison to an appropriate reference method. Colony counts were determined for each level and then log10 transformed. The transformed data were evaluated for repeatability, log-mean comparison between methods with 95% confidence interval, and r2. A 95% confidence interval range of −0.5 to 0.5 on the mean difference was used as the acceptance criterion to establish significant statistical difference between methods. The evaluations demonstrate that the Peel Plate EC method provides no statistical differences across most of the matrixes. The coliform r2 values were greater than 0.9 except in the case of skim milk (r2 = 0.77 and 0.69), sheep milk (0.84), and chocolate (0.81). In the case of skim milk, the three highest concentrations were significantly biased low compared with the reference method, whereas in the case of chocolate, the highest concentration was significantly biased high. The E. coli r2 values were greater than 0.9 except in the case of hog rinse (0.89), flume water (0.82), and chocolate (0.77). The lower values were generally from only a 1 log difference between highest and lowest concentrations except in the case of chocolate, in which the highest concentration was biased high compared with the reference method. Within-method repeatability of Peel Plate EC was similar to the reference method, with relative SDs generally less than 5% when log10 means were ≥1.5. QC data support that the Peel Plate EC is stable for 1 year when refrigerated. Incubation temperature ranges, 30–36°C, and times, 22–26 and 48 h for yogurt, were not significantly different in paired t-test comparison. The method is selective without the need for confirmation, although confirmation of coliform and E. coli was performed as part of the validation work.

Monitoring the quality and safety of food products is still considered a topical issue. The evaluation of values of the results of sampling of alimentary raw materials and food products in previous 5 years has shown that the maximum number of obtained results of sampling lies within the following intervals: less than 0,001 mg/kg for cadmium, less than 0,01 mg/kg for lead, less than 0,02 mg/kg for arsenic. To consider values of results of sampling of alimentary raw materials and food products for content of such toxic elements as cadmium, arsenic, and lead we have revealed the results of studies of sampling of 2 groups of products, namely the group ‘Milk and Diary Products’ and the group ‘Bakery and Confectionery Products’. The evaluation of results of sampling for content of arsenic in the concentration interval of less than 0,02 mg/kg and 0,02–0,05 mg/kg allows to determine the prevalence the group ‘Milk and Diary Products’ which comprises 61,7 and 32,6% of the total number of sampling. In the concentration interval of 0,05–0,10 mg/kg and 0,1–1,0 mg.kg we can highlight the prevalence of the group ‘Bakery and Confectionery Products’ which comprises 11,6 and 6,1% of the total number of sampling respectively. Evaluation of the results of sampling for content of lead in the concentration interval less than 0,01 mg/kg allows to determine the prevalence of the group ‘Milk and Dairy Products including Butter and Sour Cream’ which comprises 83,5% of the total number of sampling. In the concentration intervals of 0,01–0,03 mg/kg, 0,03–0,05 mg/kg, 0,05–0,10 mg/kg, 0,1–1,0 mg/kg the group ‘Bakery and Confectionery Products’ prevails which comprises 15,2; 6,3; 4,4; 3,2% of the total number of sampling respectively. The evaluation of results of sampling for content of cadmium in the concentration interval of less than 0,001 mg/kg allows to determine prevalence of the group ‘Bakery and Confectionery Products’ which comprises 73,5% of the total number of sampling. In the concentration intervals of 0,001–0,005 mg/kg, 0,005–0,010 mg/kg the group ‘Milk and Diary Products’ prevails which comprises 41,3 and 14,8% of the total number of sampling respectively. In the concentration intervals of 0,01–0,05 mg/kg the group ‘Bakery and Confectionery Products’ prevails which comprises 12,6% of the total number of sampling. The content of cadmium, lead, and arsenic in all the samples of food raw materials and food products does not exceed the maximum permissible concentrations which allows to make a conclusion about the low level of the delivery of these toxic elements in the human body orally with food.

Physical and chemical properties of cream multistep modes of ripening and fermentations are investigation and their role in the production of sour-cream butter is studied. The process of ripening of cream was carried out multistep, regimes were selected depending on seasonal changes in the composition of milk fat. For raw materials of the autumn-winter period, for the values of iodine number 29.1–34.5, the first stage of ripening was carried out at a temperature of 8°C for 2 hours, the second stage – at 21°C for 7 hours, the third stage – at 13°C for 10 hours. For raw of spring-summer period, for the values of iodine number 34.5–40.1, the first stage of ripening was carried out at 21°C for 6 hours, the second stage – at 13°C for 4 hours, the third stage – at 8°C for 8 hours. It has been established that individual modes of low-temperature cream preparation, taking into account seasonal changes in the composition of milk fat, make it possible to obtain cream before churning almost with the same indexes of effective viscosity. The content of the crystalline phase of milk fat under both temperature regimes was 38.7–40.1%, which is sufficient to obtain of proper consistency sour-cream butter. The content of diacetyl and volatile organic acids more depend on the level of fermentation of cream than on the technological regimes of ripening and seasonality of raw materials. It has been proved that an increase in the fermentation degree of cream promotes an increase in the acidity of plasma and the content of aroma-producing components in the butter, and, accordingly, affects the degree of the sour taste. It is recommended for the production of cultured butter to begin the cream when the acidity of the plasma reaches 60ºT, which ensures the formation of high sensorial characteristic of the finished product.

Traditional sour cream and butter are widely popular fermented dairy products in Russia for their flavor and nutrition, and contain rich microbial biodiversity, particularly in terms of lactic acid bacteria (LAB). However, few studies have described the microbial communities and metabolic character of traditional sour cream and butter. The objective of this study was to determine the bacterial microbiota and metabolic character of eight samples collected from herdsmen in Buryatia, Russia. Using single-molecule real-time (SMRT) sequencing techniques, we identified a total of 294 species and/or subspecies in 169 bacterial genera, belonging to 14 phyla. The dominant phylum was Firmicutes (81.47%) and the dominant genus was Lactococcus (59.28%). There were differences between the bacterial compositions of the sour cream and butter samples. The relative abundances of Lactococcus lactis, Lactococcus raffinolactis, and Acetobacter cibinongensis were significantly higher in sour cream than in butter, and the abundance of Streptococcus thermophilus was significantly lower in sour cream than in butter. Using a pure culture method, 48 strains were isolated and identified to represent seven genera and 15 species and/or subspecies. Among these isolates, Lactococccus lactis subsp. lactis (22.50%) was the dominant LAB species. Ultra-performance liquid chromatography–quadrupole–time of flight mass spectrometry at elevated energy was used in combination with statistical methods to detect metabolite differences between traditional sour cream and butter. A total of 27,822 metabolites were detected in all samples, and Lys-Lys, isohexanal, palmitic acid, Leu-Val, and 2′-deoxycytidine were the most dominant metabolites found in all samples. In addition, 27 significantly different metabolites were detected between the sour cream and butter samples, including short peptides, organic acids, and amino acids. Based on correlation analyses between the most prevalent bacterial species and the main metabolites in sour cream, we conclude that there may be a connection between the dominant LAB species and these metabolites. This study combined omics techniques to analyze the bacterial diversity and metabolic character of traditional sour cream and butter, and we hope that our findings will enrich species resource libraries and provide valuable resources for further research on dairy product flavor.

Mold and yeast contamination constitutes a major problem in food commodities, including dairy products, hence new natural preventive measures are in high demand. The aim of the current study is to identify and characterize novel antifungal peptides produced by lactic acid bacteria (LAB) in sour cream. By the use of a newly developed image-based 96-well plate fungal growth inhibition assay targeting Debaryomyces hansenii, combined with a range of analytical tools comprising HPLC-high-resolution mass spectrometry, ultrahigh-performance liquid chromatography-Triple Quadrupole MS and nuclear magnetic resonance spectroscopy, we successfully identified a new antifungal peptide (DMPIQAFLLY; 1211 Da) in sour cream enriched with two bioprotective LAB strains. This peptide represents a fragment of casein, the most abundant protein in milk. Presumably, the proteolytic activity of these bioprotective strains results in the observed 4-fold higher concentration of the peptide during storage. Both bioprotective strains are able to generate this peptide in concentrations up to 0.4 μM, independently of the sour cream starter culture employed. The peptide attenuates the growth rate of D. hansenii at concentrations ≥35 μM, and results in smaller cells and more compact colonies. Hence, the peptide is likely contributing to the overall preserving effect of the investigated bioprotective LAB strains.

Different strains of lactobacilli isolated from Armenian dairy products (matsoun, sour cream and different types of cheeses), were studied for antifungal activity. Lactobacillus rhamnosus MDC 9661 strain was shown to have inhibitory activity against Penicillium aurantioviolaceum and Mucor plumbeus growth. Bacterial cell-free supernatant didn’t show antifungal activity. The L. rhamnosus antifungal activity was stable to the wide range of pH from 3 to 10. This activity was high after treatment with both low temperature (− 30 °C) and lysozyme and with ultrasound. However, it was sensitive to high temperature from 45 to 80 °C and proteolytic enzymes. The results suggest the proteinaceous nature of L. rhamnosus antifungal activity associated with bacterial cell wall. L. rhamnosus MDC 9661 could be recommended as a starter for production of dairy products, functional food and preserving strain in food production.

Biopreservation represents a complementary approach to traditional hurdle technologies for reducing microbial contaminants (pathogens and spoilers) in food. In the dairy industry that is concerned by fungal spoilage, biopreservation can also be an alternative to preservatives currently used (e.g. natamycin, potassium sorbate). The aim of this study was to develop antifungal fermentates derived from two dairy substrates using a sequential approach including an in vitro screening followed by an in situ validation. The in vitro screening of the antifungal activity of fermentates derivating from 430 lactic acid bacteria (LAB) (23 species), 70 propionibacteria (4 species) and 198 fungi (87 species) was performed against four major spoilage fungi (Penicillium commune, Mucor racemosus, Galactomyces geotrichum and Yarrowia lipolytica) using a cheese-mimicking model. The most active fermentates were obtained from Lactobacillus brevis, Lactobacillus buchneri, Lactobacillus casei/paracasei and Lactobacillus plantarum among the tested LAB, Propionibacterium jensenii among propionibacteria, and Mucor lanceolatus among the tested fungi. Then, for the 11 most active fermentates, culture conditions were optimized by varying incubation time and temperature in order to enhance their antifungal activity. Finally, the antifungal activity of 3 fermentates of interest obtained from Lactobacillus rhamnosus CIRM-BIA1952, P. jensenii CIRM-BIA1774 and M. lanceolatus UBOCC-A-109193 were evaluated in real dairy products (sour cream and semi-hard cheese) at a pilot-scale using challenge and durability tests. In parallel, the impact of these ingredients on organoleptic properties of the obtained products was also assessed. In semi-hard cheese, application of the selected fermentates on the cheese surface delayed the growth of spoilage molds for up to 21 days, without any effect on organoleptic properties, P. jensenii CIRM-BIA1774 fermentate being the most active. In sour cream, incorporation of the latter fermentate at 2 or 5% yielded a high antifungal activity but was detrimental to the product organoleptic properties. Determination of the concentration limit, compatible with product acceptability, showed that incorporation of this fermentate at 0.4% prevented growth of fungal contaminants in durability tests but had a more limited effect against M. racemosus and P. commune in challenge tests. To our knowledge, this is the first time that the workflow followed in this study, from in vitro screening using dairy matrix to scale-up in cheese and sour cream, is applied for production of natural ingredients relying on a large microbial diversity in terms of species and strains. This approach allowed obtaining several antifungal fermentates which are promising candidates for dairy products biopreservation.

The purpose of this study was to analyse emulsions for vitamin D3 delivery in yoghurt and sour cream. Oil-in-water emulsions stabilised by whey proteins alone and by whey proteins plus carboxymethylcellulose were used. No change in vitamin D3 added to the yoghurt and sour cream in the form of both emulsions was observed after storage at 7 days in light and 14 days in dark at 4 °C. The results of bioavailability tests, using rats, for vitamin D3 from the fortified emulsions and yoghurt indicated that it is feasible to use stabilised emulsions as delivery systems of vitamin D3 in fortified products.

Aflatoxins are toxic fungal metabolites, which can be found in feed. Aflatoxin M1 (AFM1) is excreted into milk when ruminants ingest aflatoxin B1 contaminated feedstuffs. Due to its carcinogenic potential, contamination of milk and dairy products with AFM1 may pose a risk for consumers. Hence, it is considered a public health concern. In this survey, the level of AFM1 contamination of dairy products marketed in Costa Rica was determined by enzyme-assisted extraction, immunoaffinity clean-up and high-performance liquid chromatography coupled with a fluorescent detector (HPLC-FLD) in fluid milk (n = 70), fresh cheese (n = 70) and sour cream (n = 70) collected at local convenience stores and supermarkets. AFM1 concentrations in milk and fresh cheese ranged from 19 to 629 ng/L and from 31 to 276 ng/L, with mean values of 136 ng/L and 74 ng/L, respectively, whereas none of the sour cream samples analysed tested positive for this aflatoxin. In 30 milk samples, and 10 cheese samples, AFM1 concentrations surpassed threshold concentrations as established by the European Commission. Thus, sour cream and - to a lesser extent - cheese manufacturing seems to reduce the amount of AFM1 present in milk, possibly due to fraction redistribution or microbiological degradation. The survey results reveal improper quality control procedures in the Costa Rican dairy industry. Therefore, a surveillance programme for dairy products in our country is recommended.

Gels formed from milk by renneting or acidification under quiescent conditions may subsequently show syneresis, that is, expel liquid (whey), because the gel (curd) contracts. Under quiescent conditions, a rennet-induced milk gel may lose two-thirds of its volume, and up to 90%, or even more, if external pressure is applied. Often, syneresis is undesired, for example, during storage of products like yogurt, sour cream, cream cheese, or quark; hence, it is useful to know under what conditions syneresis can be (largely) prevented. In making cheese from renneted or acidified milk, syneresis is an essential step. Consequently, it is useful to understand and quantitatively describe syneresis as a function of milk properties and process conditions, particularly when new methods or process steps are introduced in cheesemaking.

Food powders were applied on crackers that had been coated using water, oil, emulsion, sucrose, or hydrocolloid solutions. The hydrocolloids that were used include gellan gum, kappa-carrageenan, methylcellulose, gum karaya, gum tragacanth, gum arabic, guar gum, modified starch, and maltodextrin. Solutions of similar hydrophobicity to the powder gave the greatest adhesion. NaCl, barbecue (BBQ), ranch, and sour cream & onion (SC&O) seasoning showed greatest adhesion with water, cheese powder with an emulsion of 12.5% to 25% oil, and cocoa powder with oil. For NaCl, BBQ, ranch, and SC&O seasoning, hydrocolloids improved the adhesion over using water alone, with gellan gum providing the greatest adhesion. Hydrocolloid structural differences, including the presence or absence of branching, substitution of sugar units, and molecular weight affect water binding and thickening of the hydrocolloid spray that seemed to be significant factors affecting adhesion of powders to the target surface. For cheese powder, hydrocolloids were capable of replacing the oil within an emulsion while improving or maintaining the same level of adhesion, with gum arabic providing the greatest adhesion. For cocoa powder, hydrocolloid solutions were ineffective adhesives due to differences in hydrophilicity that result in insolubility. The effect of hydrocolloid concentration on adhesion was dependent both on the hydrocolloid type and the concentration that is sprayable, with 0.5% being the optimum concentration for most gums. Adhesion using sucrose solutions was determined by particle size and relative hydrophobicity. Increasing sucrose concentration decreased adhesion of smaller particles, but increased adhesion of larger particles. Adhesion of NaCl significantly increased with decreasing NaCl size using oil, water, and sucrose solutions.

The levels of thiamine were compared between different types of milk, fermented milk products and rice milk. The analysed products were mainly from the markets, so vitamin analysis may be a good parameter for the quality of commercial food. Thiamine concentrations were determined by high performance liquid chromatography (HPLC) using a reversed-phase C-18 column with fluorescence detector. The average thiamine contents were 0.46 µg/mL for ultra high temperature (UHT), 0.39 µg/mL for pasteurized and 0.38 µg/mL for chocolate milk. Unprocessed cow milk had average thiamine concentration of 0.47 µg/mL. The highest thiamine content (11.95 µg/mL) was found in rice milk. Sour cream samples had higher concentration of thiamine (0.54 µg/mL) than yogurt (0.45 µg/mL) and sour milk (0.47 µg/mL). In the opened UHT milk packages, which were stored in refrigerator for 10 days, significant thiamine loss was not observed. Investigated products contained appropriate amounts of thiamine and had satisfactory nutritional valu...

Effects of vinegar, oil, and sour cream brines on meat quality of 4 popular cold marinades from herring were investigated in the study. Cover brine type affected the composition and nutritive value of meat as well as the sensory and microbiological quality of marinated herring. Qualitative differences resulted from cover brine penetration into meat, and from diffusion of components from meat to vinegar brine. Compared to oil and sour cream, vinegar brine contributed to increased concentrations of salt and acetic acid, hardness, color brightness of marinades meat and to increased microbial contamination of meat. Furthermore, vinegar caused nitrogen losses to 15%, including valuable products of protein hydrolysis, enzymes, and total volatile bases. The rolling up of fillets reduced diffusion even by 50%. In turn, oil and sour cream were causing mainly a higher fat content and overall sensory evaluation of the marinades.