Rapid determination of cholesterol in milk and milk products by direct saponification and capillary gas chromatography

Effect of Dietary Eicosapentaenoic and Docosahexaenoic Fatty Acid Supplementation during the Last Month of Gestation on Fatty Acid Metabolism and Oxidative Status in Charolais Cows and Calves

Fatty acids (FAs) are of utmost importance in the peripartal period for the development of the central nervous and immune systems of the newborn. The transport of polyunsaturated fatty acids (PUFAs) through the placenta is considered to be minimal in ruminants. Nevertheless, the cow's FAs are the main source of FAs for the calf during gestation. This research aimed to investigate the influence of low-dose eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation during late gestation on the FA metabolism of cows and their calves. A total of 20 Charolais cows during the last month of their gestation were included in the feeding trial and were divided into a control group (CON) and an experimental group (EPA + DHA). The latter received a supplement in the amount of 100 g/day (9.1 and 7.8 g/cow/day of EPA and DHA, respectively). Supplementation of low-dose EPA and DHA alters colostrum and milk fatty acid composition through the elevation of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) without affecting milk fat and protein concentrations and oxidative status. Plasma composition in cows was significantly altered, while the same effect was not detected in calf plasma. No significant change in mRNA expression was detected for the genes fatty acid synthase (FASN) and acetyl-CoA carboxylase alpha (ACACA).

Caciocavallo Podolico Cheese, a Traditional Agri-Food Product of the Region of Basilicata, Italy: Comparison of the Cheese's Nutritional, Health and Organoleptic Properties at 6 and 12 Months of Ripening, and Its Digital Communication

Traditional agri-food products (TAPs) are closely linked to the peculiarities of the territory of origin and are strategic tools for preserving culture and traditions; nutritional and organoleptic peculiarities also differentiate these products on the market. One such product is Caciocavallo Podolico Lucano (CPL), a stretched curd cheese made exclusively from raw milk from Podolian cows, reared under extensive conditions. The objective of this study was to characterise CPL and evaluate the effects of ripening (6 vs. 12 months) on the quality and organoleptic properties, using the technological "artificial senses" platform, of CPL produced and sold in the region of Basilicata, Italy. Additionally, this study represents the first analysis of cheese-related digital communication and trends online. The study found no significant differences between 6-month- and 12-month-ripened cheese, except for a slight increase in cholesterol levels in the latter. CPL aged for 6 and 12 months is naturally lactose-free, rich in bioactive components, and high in vitamin A and antioxidants and has a low PUFA-n6/n3 ratio. The "artificial sensory profile" was able to discriminate the organoleptic fingerprints of 6-month- and 12-month-ripened cheese. The application of a socio-semiotic methodology enabled us to identify the best drivers to create effective communication for this product. The researchers recommend focusing on creating a certification mark linked to the territory for future protection.

Exploring the Cholesterol-Modifying Abilities of Lactobacilli Cells in Digestive Models and Dairy Products

This study aimed to investigate the ability of lactic acid bacteria to remove cholesterol in simulated gastric and intestinal fluids. The findings showed that the amount of cholesterol removed was dependent on the biomass, viability, and bacterial strain. Some cholesterol binding was stable and not released during gastrointestinal transit. The presence of cholesterol affected the fatty acid profile of bacterial cells, potentially influencing their metabolism and functioning. However, adding cholesterol did not significantly impact the survival of lactic acid bacteria during gastrointestinal transit. Storage time, passage, and bacterial culture type did not show significant effects on cholesterol content in fermented dairy products. Variations in cell survival were observed among lactic acid bacteria strains in simulated gastric and intestinal fluids, depending on the environment. Higher milk protein content was found to be more protective for bacterial cells during gastrointestinal transit than fat content. Future research should aim to better understand the impact of cholesterol on lactic acid bacteria metabolism and identify potential health benefits.

Dynamic stability of cholesterol and desmosterol in human milk from four Asian countries

Cholesterol is one of the functional nutrients in human milk, which is indispensable for infant growth. In this study, the concentration of cholesterol and desmosterol in human milk from four Asian countries (n = 578), including Korea, China, Vietnam, and Pakistan, were investigated. The average cholesterol concentrations of Korea and China were similar ranging between 90.2-91.6 mg/L, but those from Vietnam and Pakistan were higher at 113.8 and 175.7 mg/L, respectively. The relative standard deviations were 31-36%, except for Pakistan (51%), showing a broad distribution of 48 to 612 mg/L. Desmosterol concentrations were similar, ranging between 11.2 and 12.8 mg/L except for Pakistan, which was lower than other countries at 9.4 mg/L. In addition, the cholesterol and desmosterol concentrations during the lactation periods were not significantly different in all four Asian countries. Mothers' BMI did not significantly impact the cholesterol and desmosterol concentration in maternal milk within the same country.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01141-9.

Nutritional and in vitro antioxidant activity analyses of formulated soymilk dessert

Soymilk (SM) is nutritionally nearly equal to milk from cows and is free of cholesterol, gluten, and lactose. This study’s objective was to formulate a cholesterol-free soymilk dessert (SOD) and compare it’s to commercial desserts (CODs). Results indicated that the CODs contain substantial amounts of cholesterol while SOD does not. Soymilk dessert has more protein, and vitamin E than CODs, but less fat and calcium. In addition, the result also highlighted that SOD has higher number of amino acids compared to CODs. The total antioxidant, flavonoids and phenolics content of SOD were significantly higher than CODs. Furthermore, the in vitro antioxidant activity of SOD and CODs by DPPH and ABTS methods revealed that the IC₅₀ of SODs significantly (p < 0.001) lower than CODs, and lower IC₅₀ indicated the higher free radical scavenging power of SODs than CODs. These findings indicated that this non-dairy SOD may provide beneficial protein, as well as minerals, and antioxidants to support the body’s various physiological functions.

Hypolipidemic activity of lactic acid bacteria: Adjunct therapy for potential probiotics

Background

Individuals with hyperlipidemia are two times more likely to develop atherosclerotic cardiovascular disease (ASCVD) as opposed to those with controlled serum total cholesterol (TC) levels. Considering the documented adverse events of the current lipid-lowering medications which ultimately affect patient’s compliance, substantial efforts have been made to develop new therapeutic strategies. Probiotics, on the other hand, are reported to have lipid-lowering activity with the added benefit of being generally well-tolerated making it an appealing adjuvant therapy.

Methods

A total of fifty Lactic acid bacteria (LAB) were isolated from raw milk (human and animal) and dairy products. Isolates demonstrating promising in vitro cholesterol removal capabilities were morphologically and biochemically characterized. Lastly, two bacterial candidates were selected for evaluation of their potential hypolipidemic activity using a laboratory animal model. Statistical differences between the means were analyzed by one-way analysis of variance (ANOVA) followed by Tukey’s post-hoc test. A p-value < 0.05 was considered statistically significant.

Results

Most of the isolates demonstrated an in vitro cholesterol removal activity. The six LAB isolates showing the highest cholesterol removal activity (36.5–55.6%) were morphologically and biochemically identified as Lactobacillus, Pediococcus, and Lactococcus species. The results demonstrated two promising antihyperlipidemic candidates, a Lactococcus lactis ssp. lactis with an in vivo significant reduction of serum triglycerides (TG) levels by 34.3%, and a Pediococcus sp. that was able to significantly reduce both the serum TC and TG levels by 17.3% and 47.0%, respectively, as compared to the diet-induced hyperlipidemic animal group.

Conclusion

This study further supports the growing evidence regarding the antihyperlipidemic activity among probiotics, presenting them as a promising therapeutic approach for the management of hyperlipidemia.

Influence of Murta (Ugni molinae Turcz) Powder on the Frankfurters Quality

Frankfurters are one of the most demanded meat products in the world due to their low cost and good taste. However, they contain up to 30% animal fat, which is negative for the consumer’s health. Moreover, high-fat contents could also decrease frankfurter sensory properties, since it accelerates the rancidity of the products. This fact is highly dependent on the fatty acids composition since the unsaturation promotes oxidative reactions. Currently, strategies have been developed to replace animal fat with vegetable oils or the inclusion of new raw materials. The murta (Ugni molinae Turcz), an endemic plant in Chile, is a specie that contains high levels of flavonoids in its fruits and has a pleasant flavor, as well as a sweet and floral aroma. However, the effect of the addition of these fruits in the formulation of meat products has been scarcely studied. The present study aims to reduce the use of synthetic additives using natural ones (murta powder). Therefore, this research evaluated the influence of the inclusion of murta on the chemical, sensory, and instrumental parameters of traditional frankfurters. Three batches of frankfurters were manufactured: control sausages without additives (T0); samples with chemical antioxidant (T1); and with murta fruit powder (T2). The chemical composition, physicochemical parameters and sensory properties were determined. Frankfurters made with murta (T2) presented middle values in energy, moisture and sodium compared with control. Also, the reformulated sausages (T2) presented the lowest water holding capacity, redness (a*) and yellowness and the highest values of fat and carbohydrates. Regarding fatty acids content, the most important changes were observed in the C18:0 and C14:0 (T2 presented the lowest values) and C18:2n-6 (T2 had the highest values), but minimal differences were observed in the total SFA, MUFA and PUFA content. Cholesterol content from T2 were similar to the control samples, and T1 presented the highest values. Although these differences, both chemical and nutritional quality of all frankfurters manufactured in the present study were very similar among treatments. Finally, according to the sensory analysis, T2 presented better acceptability and sensory characteristics compared with the other treatments (p ≤ 0.05). Therefore, the inclusion of murta in the production of frankfurters could be a strategy to improve the sensory characteristics of this product with minimal changes in chemical and nutritional properties. However, the effect of murta on oxidative stability and frankfurter shelf-life should be studied in depth in future research.

Effect of Dietary Brown Seaweed (Macrocystis pyrifera) Additive on Meat Quality and Nutrient Composition of Fattening Pigs

The objective of this study was to evaluate the effects of dietary brown seaweed (Macrocystis pyrifera) additive (SWA) on meat quality and nutrient composition of commercial fattening pigs. The treatments were: Regular diet with 0% inclusion of SWA (CON); Regular diet with 2% SWA (2%-SWA); Regular diet with 4% SWA (4%-SWA). After slaughtering, five carcasses from each group were selected, and longissimus lumborum (LL) samples were taken for meat quality and chemical composition analysis. Meat quality traits (except redness intensity) were not affected (p > 0.05) by treatments. Samples from the 4%-SWA treatment showed the lowest a value than those from the 2%-SWA and CON treatments (p = 0.05). Meat samples from the 4%-SWA group contained 3.37 and 3.81 mg/100 g more of muscle cholesterol than CON and 2% SWA groups, respectively (p < 0.05). The SWA treatments affected (p ≤ 0.05) the content of ash, Mn, Fe, and Cu. The LL samples from 4%-SWA had the highest content of ash; however, they showed 0.13, 0.45, and 0.23 less mg/100 g of Mn, Fe, and Zn, respectively, compared to samples from CON (p ≤ 0.05). Fatty acids composition and macro minerals content (Na, Mg, and K) did not show variation due to the SWA treatments. Further studies are needed to understand the biological effects of these components on adipogenesis, cholesterol metabolism, and mineral deposition in muscle.

The effect of high monacolin K red yeast rice supplement on performance, egg quality, egg yolk cholesterol, plasma lipids and enzyme profile of laying hens

Context Reducing egg cholesterol has been a major goal of many researchers over four decades. Monacolin K, a 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitor, identical to the active ingredient in the prescription statin drug lovastatin, could be a promising feed supplement for layers. Aims To determine the effects of high monacolin K red yeast rice (RYR) supplement on feed intake, egg production, egg cholesterol content, plasma lipid and enzyme metabolites in laying hens. Methods Hyline brown layers were fed RYR supplement at 0, 0.2, 0.4, 0.8 and 1.6% of the diet for 6 weeks. Total and daily feed intake, egg production, egg weights and feed conversion ratio between the RYR treated groups and the control were compiled. Egg cholesterol and egg quality at the 3rd and 6th week of the feeding trial were analysed. Plasma lipids and enzymes were sampled towards the end of the trial. Key results Egg cholesterol were significantly lower (P &lt; 0.05) in the 0.8 and 1.6% RYR supplemented group. Supplementation with 0.8% RYR resulted in 11.16% reduction in egg cholesterol at the 3rd week with no further improvements with longer feeding. There were no significant differences (P &gt; 0.05) in total and daily feed intake, egg production, egg weights and feed conversion ratio (FCR) between the RYR treated and control group. Total plasma cholesterol and triglycerides were significantly lower (P &lt; 0.05) in the 0.8 and 1.6% RYR supplemented group when compared with the control group. RYR supplementation exert no significant differences (P &gt; 0.05) in plasma enzyme levels. Conclusions The present study suggests that RYR supplementation of 0.8% resulted in egg cholesterol reduction by 11.16% with no adverse effects on laying hens. Implications The feeding trial showed that RYR supplement can be used as a feed additive in layer diets to lower egg cholesterol, plasma cholesterol and triglycerides with no adverse effects on layer egg production and plasma enzymes over the feeding period.

Cholesterol, fatty acids profile and the indices of atherogenicity and thrombogenicity of raw lamb and mutton offal

Dietary fats may affect blood lipid levels and the development of cardiovascular diseases. Offal, may contribute to food security in marginalised communities and information on the contribution to dietary fat intake is needed to inform dietary guidelines and recommendations and consumers. This study aimed to describe the fatty acid profile, cholesterol content and indexes of lipid quality. The fatty acid profile and cholesterol were determined by gas chromatography coupled with flame ionisation detection (GC-FID). To evaluate lipid quality the indices of atherogenicity (IA) and thrombogenicity (IT) were calculated. Offal products can contribute beneficial fatty acids to the diet, not only in terms of essential fatty acids such as linoleic (C18:2n-6) and alpha linolenic (C18:3n-3) acids, but also the polyunsaturated fatty acids, arachidonic (C20:4n-6) and eicosapentaenoic (C20:5n3) acids. The offal studied in the present work showed a P/S ratio of 0.04-0.12 and the n-6/n-3 ratio varied between 3.9 and 12.5.

Assimilation of Cholesterol by Monascus purpureus

Monascus purpureus, a filamentous fungus known for its fermentation of red yeast rice, produces the metabolite monacolin K used in statin drugs to inhibit cholesterol biosynthesis. In this study, we show that active cultures of M. purpureus CBS 109.07, independent of secondary metabolites, use the mechanism of cholesterol assimilation to lower cholesterol in vitro. We describe collection, extraction, and gas chromatography-flame ionized detection (GC-FID) methods to quantify the levels of cholesterol remaining after incubation of M. purpureus CBS 109.07 with exogenous cholesterol. Our findings demonstrate that active growing M. purpureus CBS 109.07 can assimilate cholesterol, removing 36.38% of cholesterol after 48 h of incubation at 37 °C. The removal of cholesterol by resting or dead M. purpureus CBS 109.07 was not significant, with cholesterol reduction ranging from 2.75-9.27% throughout a 72 h incubation. Cholesterol was also not shown to be catabolized as a carbon source. Resting cultures transferred from buffer to growth media were able to reactivate, and increases in cholesterol assimilation and growth were observed. In growing and resting phases at 24 and 72 h, the production of the mycotoxin citrinin was quantified via high-performance liquid chromatography-ultraviolet (HPLC-UV) and found to be below the limit of detection. The results indicate that M. purpureus CBS 109.07 can reduce cholesterol content in vitro and may have a potential application in probiotics.

Sampling protocol for the determination of nutrients and contaminants in fish and other seafood - The EAF-Nansen Programme

Seafood plays a central role in global food and nutrition security. However, there is a lack of data on the concentration of nutrients and contaminants in fish and other seafood, especially in low- and middle-income countries. In order to assess the potential risks and benefits associated with seafood intake, reliable and up-to-date food composition data is crucial. The quality of food composition data is affected by several factors, such as sampling protocols and the suitability and quality of the methods applied for sample preparation and analysis. In this paper, we describe the sampling methodology and protocols related to the sampling of fish and other seafood and the corresponding analytical methods used to analyse the nutrient and contaminant content of such species. For nutrients, the determination of protein, fat, ash, energy, fatty acids, cholesterol, and amino acids is described, in addition to analyses for determination of the vitamin and mineral content in fish and other seafood. For contaminants, analyses for the determination of organic pollutants and microplastics are described. The methodology described in this paper is used for sampling data through scientific surveys in low- and middle-income countries with research vessel Dr. Fridtjof Nansen under the EAF-Nansen Programme. The Programme aims to improve knowledge on the nutritional composition of fish and ensure the fish is safe to consume.•

In this paper, we describe the sampling protocols used for sampling fish and other seafood during scientific surveys under the EAF-Nansen Programme.

•

This paper describes the methodology and quality control for analysing nutrients and contaminants in fish and other seafood.

The Comparison of Nutritional Value of Human Milk with Other Mammals' Milk

(1) Background: The variation in the concentration of different components found in milk depends on mammalian species, genetic, physiological, nutritional factors, and environmental conditions. Here, we analyse, for the first time, the content of different components (cholesterol concentration and fatty acids composition as well as the overall fat and mineral content determined using the same analytical methods) in milk of different mammal species. (2) Methods: The samples (n = 52) of human, cow, sheep, goat and mare milk were analyzed in triplicate for: cholesterol concentration, fatty acids profile and fat and mineral content (calcium, magnesium, sodium, potassium, iron, zinc). (3) Results: The highest fat content was reported in sheep milk (7.10 ± 3.21 g/dL). The highest cholesterol concentration was observed in bovine (20.58 ± 4.21 mg/dL) and sheep milk (17.07 ± 1.18 mg/dL). The saturated fatty acids were the lowest in human milk (46.60 ± 7.88% of total fatty acids). Goat milk had the highest zinc (0.69 ± 0.17 mg/dL), magnesium (17.30 ± 2.70 mg/dL) and potassium (183.60 ± 17.20 mg/dL) content. Sheep milk had the highest sodium (52.10 ± 3.20 mg/dL) and calcium (181.70 ± 17.20 mg/dL) concentration values. (4) Conclusions: The differences in nutritional value of milk could be perceived as a milk profile marker, helping to choose the best food for human nutrition.

The comparison of HPLC and spectrophotometric method for cholesterol determination

The present study was carried out to compare two different analytical methods (HPLC and spectrophotometric) for determination of cholesterol content in milk while cholesterol in food is important not only for the nutritional value setting of foods but also due to the validation of a fast, reliable and economical method for studying the possible mechanism of its reduction. Spectrophotometric determination of cholesterol content was based on the Liebermann-Burchard (LB) reaction among cholesterol, ethyl acetate, acetic anhydride, plus concentrated H2SO4 and measuring absorbance of formed color at 625 nm. HPLC method was performed by column chromatography on reverse phase C18 with DAD detection at 205 nm. The methods were applied to the milk sample. The achieved LOD and LOQ for HPLC were 2.13 mg.kg-1 and 6.45 mg.kg-1, respectively, while for spectrophotometric method were 12.55 and 38.04 mg.kg-1. The difference between cholesterol content determined by both methods was statistically insignificant at p <0.05. Therefore, it can be concluded that both methods are suitable for determination of cholesterol content in milk, however, HPLC method exhibited higher sensitivity and lower limits of detection or quantification, respectively.

Targeted genotyping to identify potential functional variants associated with cholesterol content in bovine milk

High blood cholesterol concentration, mainly caused by high dietary cholesterol, is a potential risk factor for human health. Dairy products are important sources of human dietary cholesterol intake. Therefore, monitoring bovine milk cholesterol concentration is important for human health benefit. Genetic selection for improvement of cow milk cholesterol content requires understanding of the genetics of milk cholesterol. For this purpose, we performed analyses of additive and dominance effects of 126 potentially functional SNPs within 43 candidate genes with milk cholesterol content [expressed as mg of cholesterol in 100 g of fat (CHL_fat) or in 100 mg of milk (CHL_milk)]. The additive and dominance effects of SNPs rs380643365 in AGPAT1 (P = 0.04) and rs134357240 in SOAT1 (P = 0.035) genes associated significantly with CHL_fat. Moreover, five (rs109326954 and rs523413537 in DGAT1, rs109376747 in LDLR, rs42781651 in FAM198B and rs109967779 in ACAT2) and four (rs137347384 in RBM19, rs109376747 in LDLR, rs42016945 in PPARG and rs110862179 in SCAP) SNPs were significantly associated with CHL_milk (P < 0.05) based on additive and dominance effect analyses respectively. Rs109326954 and rs523413537 in DGAT1 explained a considerable portion of the phenotypic variance of CHL_milk (7.54 and 6.84% respectively), and might be useful in selection programs for reduced milk cholesterol content. Several significantly associated SNPs were in genes (such as ACAT2 and LDLR) involved in cholesterol metabolism in the liver or cholesterol transport, suggesting multiple mechanisms regulating milk cholesterol content. Nine and seven SNPs identified by additive or dominance effect analyses associated significantly with milk yield and fat yield respectively. Further analyses are required to better understand the consequences of these variants and their potential use in genomic selection of the studied traits.

Screening for Cholesterol-Lowering Probiotics from Lactic Acid Bacteria Isolated from Corn Silage Based on Three Hypothesized Pathways

A total of 85 strains of lactic acid bacteria were isolated from corn silage in this study and analyzed in vitro for their cholesterol removal, NPC1L1 protein down-regulation and bile salt deconjugation ability, respectively. Nineteen strains were selected for further analysis for their probiotic potential. Finally, 3 strains showing better probiotic potential were evaluated for their cholesterol-lowering activity in hamsters. The strains showing the greater cholesterol removal and NPC1L1 protein down-regulation activity had no significant effects on serum and hepatic cholesterol levels in hamsters (p > 0.05). However, Lactobacillus plantarum CAAS 18008 (1 × 10⁹ CFU/d) showing the greater bile salt deconjugation ability significantly reduced serum low-density lipoprotein cholesterol, total cholesterol, and hepatic total cholesterol levels by 28.8%, 21.7%, and 30.9%, respectively (p < 0.05). The cholesterol-lowering mechanism was attributed to its bile salt hydrolase activity, which enhanced daily fecal bile acid excretion levels and thereby accelerated new bile acid synthesis from cholesterol in liver. This study demonstrated that the strains showing greater cholesterol removal and NPC1L1 protein down-regulation activity in vitro hardly reveal cholesterol-lowering activity in vivo, whereas the strains showing greater bile salt deconjugation ability in vitro has large potential to decrease serum cholesterol levels in vivo.

An energy-protein feed additive containing different sources of fat improves feed intake and milk performance of dairy cows in mid-lactation

This research paper addresses the hypothesis that calcium salts combined with whole linseed and heat-treated rapeseed cake in one feed additive may efficiently stimulate the productivity of dairy cows and have a positive effect on the functional (health-promoting) properties of milk fat. The article proposes the composition of such an additive (EFA) and evaluates its nutritional effect in the diet of mid-lactation dairy cows. Forty multiparous Polish Holstein-Friesian (PHF) dairy cows were allocated to one of four treatments (10 cows/treatment) and fed a TMR diet without EFA or with EFA in the amount of 1, 2 or 3 kg/d per head for a 63-d-period. Individual intake of dry matter (DMI) and nutrients was determined, as was milk yield and composition, including fatty acid profile, fat soluble vitamins, cholesterol and phospholipids (PLs). Irrespective of the treatment group, cows fed diets with EFA had higher (P &lt; 0.05) DMI, milk yield and milk vitamin D3 and K2 concentration but lower (P &lt; 0.01) milk protein, fat and cholesterol contents. The additive did not affect the milk concentrations of β-carotene or vitamin A or E. The PLs content was correlated with fat concentration in the milk and decreased as the level of EFA in the diet increased. An increase in phosphatidylcholine in total PLs was accompanied by a reduction in the proportion of sphingomyelin (P &lt; 0.05). The use of EFA increased the proportion of polyunsaturated fatty acids (PUFA) in the total fatty acids in the milk. The addition of EFA in the amount of 3 kg increased the proportion of PUFA by 77% (P &lt; 0.05). In conclusion, the use of an energy-protein feed additive (EFA) increases feed intake and milk yield in cows and alters milk fat composition, improving its functional properties. Higher milk production compensates for the decrease in solids concentration in the milk, which has no effect on their daily yield.

Genetic parameters of milk cholesterol content in Holstein cattle

This study aimed to estimate heritability for milk cholesterol (CHL) and genetic correlations between milk CHL and other production traits (test-day milk, fat, and protein yields, fat and protein percentages, and somatic cell score). Milk CHL content was determined by gas chromatography and expressed as mg of CHL in 100 g of fat (CHL_fat) or in 100 mg of milk (CHL_milk). Univariate models were used to estimate variances and heritability, whereas bivariate models were used to compute correlations using data from 1793 cows. The average concentrations (standard deviation) of CHL_fat and CHL_milk were 275.63 (75) mg and 11.16 (3.63) mg, respectively. Milk CHL content was significantly affected by days in milk and herd (P < 0.05), but not by parity, regardless of the scale of expression. Heritability estimates for CHL_fat and CHL_milk were 0.06 ± 0.04 and 0.17 ± 0.06, respectively. Phenotypic and genetic correlations between CHL_fat and CHL_milk were 0.82 and 0.44 ± 0.24, respectively. CHL_fat had nonsignificant genetic correlations with all production traits, whereas CHL_milk had significant (P < 0.05) genetic correlations with milk yield (−0.47), fat yield (0.51), protein percentage (0.56), and fat percentage (0.88). This is the first study to estimate genetic parameters for milk CHL content. Further studies are required to assess the possibility of genetically selecting cows with lower milk CHL content.

Lactic acid bacteria with cholesterol-lowering properties for dairy applications: In vitro and in situ activity

Cholesterol-lowering activity is one of the most promising properties of lactic acid bacteria with probiotic characteristics. In the present study, 58 potentially probiotic lactic acid bacteria were tested for their ability to survive in vitro digestion and reduce cholesterol in a medium containing cholesterol and bile acids. The best-performing strains (Lactobacillus casei VC199, Lactobacillus paracasei ssp. paracasei SE160 and VC213, Lactobacillus plantarum VS166 and VS513, Enterococcus faecium VC223, and Enterococcus lactis BT161) resulted in a 42 to 55% reduction of the cholesterol level in broth and were further tested in cheese manufacture. The cholesterol content in all the cheeses decreased with ripening. All the strains were present in the cheese at levels higher than 10⁷ cfu/g until 60 d of ripening, the highest reductions (up to 23%) being obtained when Lb. paracasei ssp. paracasei VC213 and E. lactis BT161 were added during the cheese-making. The adjunct cultures had no negative effect on the sensory characteristics of the cheese. Thus, these strains with proven in vitro properties are good candidates for novel probiotic-containing formulations and could be used to functionalize foods such as dairy fermented products.

Genome wide association study identifies novel potential candidate genes for bovine milk cholesterol content

This study aimed to identify single nucleotide polymorphisms (SNPs) associated with milk cholesterol (CHL) content via a genome wide association study (GWAS). Milk CHL content was determined by gas chromatography and expressed as mg of CHL in 100 g of fat (CHL_fat) or in 100 mg of milk (CHL_milk). GWAS was performed with 1,183 cows and 40,196 SNPs using a univariate linear mixed model. Two and 20 SNPs were significantly associated with CHL_fat and CHL_milk, respectively. The important regions for CHL_fat and CHL_milk were at 41.9 Mb on chromosome (BTA) 17 and 1.6-3.2 Mb on BTA 14, respectively. DGAT1, PTPN1, INSIG1, HEXIM1, SDS, and HTR5A genes, also known to be associated with human plasma CHL phenotypes, were identified as potential candidate genes for bovine milk CHL. Additional new potential candidate genes for milk CHL were RXFP1, FAM198B, TMEM144, CXXC4, MAML2 and CDH13. Enrichment analyses suggested that identified candidate genes participated in cell-cell signaling processes and are key members in tight junction, focal adhesion, Notch signaling and glycerolipid metabolism pathways. Furthermore, identified transcription factors such as PPARD, LXR, and NOTCH1 might be important in the regulation of bovine milk CHL content. The expression of several positional candidate genes (such as DGAT1, INSIG1 and FAM198B) and their correlation with milk CHL content were further confirmed with RNA sequence data from mammary gland tissues. This is the first GWAS on bovine milk CHL. The identified markers and candidate genes need further validation in a larger cohort for use in the selection of cows with desired milk CHL content.

Sensory quality of milk fat with low cholesterol content fractioned by molecular distillation

BACKGROUND

Anhydrous milk fat (AMF) is a valuable ingredient in several industries, but its cholesterol content is a disadvantage because it is associated with several diseases. The objective of this study was to remove the largest possible amount of cholesterol from AMF by molecular distillation and to analyze the sensory properties of the obtained product. AMF was subjected to various molecular distillation arrangements.

RESULTS

The first set of experiments involved molecular distillations performed over a range of evaporation temperatures. Then, according to the outcome of the first set of experiments, a second set of experiments was carried out in order to study the effect of the feeding flow rate. Finally, the number of distillation stages was modified.

CONCLUSION

The best results were obtained in a three-stage arrangement, in which ∼60% of cholesterol was removed with a 30.48% distillate yield. The sensory properties of this distillation cut were also the most similar to those of the untreated milk fat. © 2018 Society of Chemical Industry.

Effect of fortification of milk with omega-3 fatty acids, phytosterols and soluble fibre on the sensory, physicochemical and microbiological properties of milk

BACKGROUND

The effect of the addition of flaxseed oil (FO), phytosterols (PS) and polydextrose (PDX) on the physicochemical and sensory properties of milk was investigated, as they are known to impart health benefits.

RESULTS

For incorporating PS, a hydrophobic substance, FO and milk fat (MF) as an oil source, an emulsifier (DATEM) and PDX solution as an aqueous medium were used for the preparation of emulsion. Three emulsion formulations A (8 g PS, 8 g FO, 20 g PDX, 6 g MF), B (10 g PS, 10 g FO, 20 g PDX, 4 g MF) and C (12 g PS, 12 g FO, 20 g PDX, 2 g MF) were prepared and added individually to milk at a level of 50 g kg^-1 . Based on sensory evaluation, formulation B was selected for fortification of milk. The fortified milk kept well at refrigerated temperature for 1 week, and changes in sensory, physicochemical and microbiological properties were comparable to those of control milk. The level of fortificants did not decrease in the milk after 1 week of storage.

CONCLUSION

An emulsion containing FO, PS and PDX could successfully serve as a potential delivery system for enhancing the nutritional and therapeutic potential of milk. © 2017 Society of Chemical Industry.

Quality attributes of dahi prepared from milk fortified with omega-3 fatty acids, phytosterols and polydetxrose

In the present study, dahi prepared using milk fortified with omega-3 fatty acids (flaxseed oil), phytosterols and soluble fibre (polydextrose) through an oil-in-water emulsion was evaluated for the physico-chemical and sensory quality. The levels of fortificants in fortified dahi were also estimated. Fortification process did not affect the degree of fermentation in terms of pH and acidity. Sensory scores of fortified and control dahi did not differ significantly. Fortified dahi had lower viscosity, firmness and consistency, and higher water holding capacity (WHC) compared to control; however, significant differences were not observed in firmness and consistency values. Storage study indicated that pH, acidity, %WHC, firmness and consistency values and lactic acid bacterial counts did not differ significantly throughout storage period in both the dahi samples and recorded good sensory acceptability during storage. Fortified dahi provides 282.53 mg, 415.92 mg and 1.019 g of α-linolenic acid, total phytosterols and polydextrose, respectively per 100 g of product. Moreover, no loss in the initial content of ALA, phytosterols and polydextrose had occurred after 8 days of storage period. The present study suggests the feasibility of adding flaxseed oil, phytosterols and polydextrose as functional ingredients in the form of water soluble emulsion to milk, which could be converted to dahi with acceptable properties and enhanced nutritional and therapeutic potency.

Lipidomic and Antioxidant Response to Grape Seed, Corn and Coconut Oils in Healthy Wistar Rats

Specialty oils differ in fatty acid, phytosterol and antioxidant content, impacting their benefits for cardiovascular health. The lipid (fatty acid, phytosterol) and antioxidant (total phenolics, radical scavenging capacity) profiles of grapeseed (GSO), corn (CO) and coconut (CNO) oils and their physiological (triacylglycerides, total and HDL-cholesterol and antioxidant capacity (FRAP) in serum and fatty acid and phytosterol hepatic deposition) and genomic (HL, LCAT, ApoA-1 and SR-BP1 mRNA hepatic levels) responses after their sub-chronic intake (10% diet for 28 days) was examined in healthy albino rats. Fatty acid, phytosterol and antioxidant profiles differed between oils (p ≤ 0.01). Serum and hepatic triacylglycerides and total cholesterol increased (p ≤ 0.01); serum HDL-Cholesterol decreased (p < 0.05); but serum FRAP did not differ (p > 0.05) in CNO-fed rats as compared to CO or GSO groups. Hepatic phytosterol deposition was higher (+2.2 mg/g; p ≤ 0.001) in CO- than GSO-fed rats, but their fatty acid deposition was similar. All but ApoA-1 mRNA level increased in GSO-fed rats as compared to other groups (p ≤ 0.01). Hepatic fatty acid handling, but not antioxidant response, nor hepatic phytosterol deposition, could be related to a more efficient reverse-cholesterol transport in GSO-fed rats as compared to CO or CNO.

Purification and characterisation of the extracellular cholesterol oxidase enzyme from Enterococcus hirae

BACKGROUND

Recently many efforts are being carried out to reduce cholesterol in foods. Out of the 50 selected isolates that were tested using the agar well diffusion method to assess their ability to decompose cholesterol, 24 bacterial isolates were screened based on their cholesterol-decomposition ability in liquid media.

RESULTS

The bacterial isolate that displayed the highest cholesterol oxidase activity was identified as Enterococcus hirae. The maximal growth and cholesterol decomposition were achieved with a 1-day incubation under static conditions at 37 °C in cholesterol basal medium adjusted to pH 7 supplemented with 1 g/l cholesterol as the substrate, no additional carbon or nitrogen sources and 0.5 % CaSO4. The cholesterol oxidase enzyme (ChoX) produced by E. hirae was extracted at an (NH4)2SO4 saturation level of 80 % and purified with 79 % yield, resulting in 2.3-fold purification. The molecular weight of (ChoX) was 60 kDa. The optimal conditions required for the maximal activity of the purified COD enzyme produced by E. hirae were 30 min, 40 °C, pH 7.8, substrate concentration of 1 g/l and 200 ppm of MgCl2. The enzyme maintained approximately 36 % and 58.5 % of its activity after 18 days of storage at 4-8 °C. Also, the enzyme loss its activity by gradual thermal treatment, but it maintained 58.5 % of its activity at 95 °C for 2 hr.

CONCLUSIONS

E. hirae Mil-31 isolated from milk had a great capacity to decompose cholesterol in basal medium supplemented with cholesterol under its optimal growth conditions. Decomposition process of cholesterol by this strain results from its production of cholesterol oxidase enzyme (ChoX). The highest specific enzyme activity and highest purification fold of purified enzyme were achieved after using Sephadex G-100.

Influence of stage of lactation and year season on composition of mares' colostrum and milk and method and time of storage on vitamin C content in mares' milk

BACKGROUND

Mares' milk is becoming increasingly popular in Western Europe. This study was thus aimed at investigating the impact of stage of lactation and season on chemical composition, somatic cell count and some physicochemical parameters of mares' colostrum and milk, and at developing a method for the determination of vitamin C (ascorbic acid) in mares' milk and to determine its content in fresh and stored milk.

RESULTS

The analysis conducted showed an effect of the stage of lactation on contents of selected chemical components and physicochemical parameters of mares' milk. In successive lactation periods levels of fat, cholesterol, energy value, citric acid and titratable acidity decreased, whereas levels of lactose and vitamin C, as well as the freezing point, increased. Analysis showed that milk produced in autumn (September, October, November) had a higher freezing point and lower concentrations of total solids, protein, fat, cholesterol, citric acid and energy value in comparison to milk produced in summer (June, July, August). Mares' milk was characterised by low somatic cell count throughout lactation. In terms of vitamin C stability the most advantageous method of milk storage was 6-month storage of lyophilised milk.

CONCLUSION

In general, the results confirmed that mares' milk is a raw material with a unique chemical composition different from that produced by other farm animals.

Chemical Compositions of Egg Yolks and Egg Quality of Laying Hens Fed Prebiotic, Probiotic, and Synbiotic Diets

A 16-wk feeding experiment was conducted to investigate the effects of a prebiotic, isomaltooligosaccharide (IMO), a probiotic, PrimaLac®, and their combination as a synbiotic on the chemical compositions of egg yolks and the egg quality of laying hens. One hundred and sixty 16-wk-old Hisex Brown pullets were randomly assigned to 4 dietary treatments: (i) basal diet (control), (ii) basal diet + 1% IMO (PRE), (iii) basal diet + 0.1% PrimaLac® (PRO), and (iv) basal diet + 1% IMO + 0.1% PrimaLac® (SYN). PRE, PRO, or SYN supplementation not only significantly (P < 0.05) decreased the egg yolk cholesterol (24- and 28-wk-old) and total saturated fatty acids (SFA; 28-, 32-, and 36-wk-old), but also significantly (P < 0.05) increased total unsaturated fatty acids (UFA; 28-, 32-, and 36-wk-old), total omega 6 and polyunsaturated fatty acids (PUFA), including linoleic and alpha-linolenic acid levels in the eggs (28-wk-old). However, the total lipids, carotenoids, and tocopherols in the egg yolks were similar among all dietary treatments in the 24-, 28-, 32-, and 36-wk-old hens. Egg quality (Haugh unit, relative weights of the albumen and yolk, specific gravity, shell thickness, and yolk color) was not affected by PRE, PRO, or SYN supplementation. The results indicate that supplementations with IMO and PrimaLac® alone or in combination as a synbiotic might be useful for improving the cholesterol content and modifying the fatty acid compositions of egg yolk without affecting the quality of eggs from laying hens between 24 and 36 wk of age.

Alternative to decrease cholesterol in sheep milk cheeses

The presence of cholesterol in foods is of nutritional interest because high levels of this molecule in human plasma are associated with an increasing risk of cardiovascular disease and nowadays consumers are demanding healthier products. The goal of this experiment was to diminish the cholesterol content of Manchego, the most popular Spanish cheese manufactured from ewes milk. For this purpose three bulk milks coming from dairy ewe fed with 0 (Control), 3 and 6% of linseed supplement on their diet were used. Nine cheeses (3 per bulk milk) were manufactured and ripened for 3 months. Cholesterol of ewes milk cheese from 6% to 12% linseed supplemented diets decreased by 9.6% and 16.1% respectively, therefore supplying a healthier profile. In a second experiment, different sources of unsaturated fatty acids (rich in oleic, linoleic and α-linolenic acids) were supplemented to dairy ewes and no significant differences were found on cheese cholesterol levels.

Effect of dietary extruded linseed, verbascoside and vitamin E supplements on yield and quality of milk in Lacaune ewes

Milk yield and milk qualitative parameters were evaluated in Lacaune ewes on a diet supplemented with extruded linseed, verbascoside and vitamin E. A 98 d-trial was conducted on 44 ewes and started 40±2 d post partum. The animals were divided into four homogeneous groups of eleven animals each; one control group (CON) without extruded linseed and dietary supplements, and the diet of the other three experimental groups was enhanced with extruded linseed (L group), extruded linseed-verbascoside (LVB group), and extruded linseed-verbascoside-vitamin E (LVBE group). All animals individually received an isoenergetic diet, consisting of 700 g concentrated feed and meadow hay ad libitum. Body weight, body condition score, milk yield and milk qualitative parameters were assessed. LVB and LVBE groups resulted in a significant improvement (P<0·05) in milk yield due to the verbascoside supplementation. The extruded linseed supplementation L, LVB and LVBE groups produced a milk fat increase and a better milk fatty acid profile in terms of a higher monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) content and a reduced saturated fatty acid (SFA) content, a lower n-6/n-3 ratio and atherogenic and thrombogenic index. The dietary verbascoside supplementation in the LVB and LVBE group resulted in a better milk quality due to the low cholesterol level and higher vitamin A and E contents, in addition to an increased oxidative stability highlighted by the lower thiobarbituric acid reactive substances (TBARS) level. Thus, the addition of extruded linseed and verbascoside supplements improved milk yield and quality both from a chemical and nutritive point of view.

Comparison of Physicochemical and Sensory Properties between Cholesterol-removed Gouda Cheese and Gouda Cheese during Ripening

This study was performed to compare physicochemical and sensory properties of cholesterol-removed Gouda cheese (CRGC) and Gouda cheese made in the laboratory during ripening. Composition, short-chain free fatty acids (SCFFA), texture, color, and sensory properties were measured. In chemical composition analyses, moistures were significantly different between control cheeses (42.86%) and sample cheese (48.32%) (p<0.05). But fat and protein in the control and the sample were 32.77, 22.45 and 31.35, 20.39%, respectively, and were not significantly different (p>0.05). The amount of cholesterol in control was 82.52 mg/100 g and the percentage of cholesterol removal was 90.7%. SCFFA increased gradually during ripening and its level of CRGC increased and significantly different from that of control (p<0.05). The texture, hardness, gumminess, and chewiness were significantly increased, but cohesiveness and springiness were not increased in both cheeses during ripening periods (p>0.05). In comparison of the control and sample cheeses, hardness, and springiness were not significantly different, but cohesiveness, gumminess, and chewiness were different (p<0.05). In color measurement, all color values were not different between CRGC and control (p>0.05). However, L* value decreased, while a* and b* values tended to increase significantly (p<0.05). In sensory properties, appearance, aroma, flavor and taste, and texture were significantly increased except buttery and nutty in aroma and sweetness in taste in both cheeses, and were not significantly different between the control and sample cheeses during ripening (p>0.05). Therefore, this study suggests that the quality of cholesterol-removed Gouda cheese is not different from the control cheese.