The Role of Lactic Acid Bacteria in Milk Fermentation

Species of lactic acid bacteria (LAB) represent as potential microorganisms and have been widely applied in food fermentation worldwide. Milk fermentation process has been relied on the activity of LAB, where transformation of milk to good quality of fermented milk products made possible. The presence of LAB in milk fermentation can be either as spontaneous or inoculated starter cultures. Both of them are promising cultures to be explored in fermented milk manufacture. LAB have a role in milk fermentation to produce acid which is important as preservative agents and generating flavour of the products. They also produce exopolysaccharides which are essential as texture formation. Considering the existing reports on several health-promoting properties as well as their generally recognized as safe (GRAS) status of LAB, they can be widely used in the developing of new fermented milk products.

A post-GWAS confirming the genetic effects and functional polymorphisms of AGPAT3 gene on milk fatty acids in dairy cattle

Background: People are paying more attention to the healthy and balanced diet with the improvement of their living standards. Milk fatty acids(FAs) have been reported that they were related to some atherosclerosis and coronary heart diseases in human. In our previous genome-wide association study(GWAS) on milk FAs in dairy cattle, 83 genomewide significant single nucleotide polymorphisms(SNPs) were detected. Among them, two SNPs, ARS-BFGL-NGS-109493 and BTA-56389-no-rs associated with C18 index(P = 0.0459), were located in the upstream of 1-acylglycerol-3-phosphate O-acyltransferase 3(AGPAT3) gene. AGPAT3 is involved in glycerol-lipid, glycerol-phospholipid metabolism and phospholipase D signaling pathways. Hence, it was inferred as a candidate gene for milk FAs. The aim of this study was to further confirm the genetic effects of the AGPAT3 gene on milk FA traits in dairy cattle.Results: Through re-sequencing the complete coding region, and 3000 bp of 5′ and 3′ regulatory regions of the AGPA T3 gene, a total of 17 SNPs were identified, including four in 5′ regulatory region, one in 5′ untranslated region(UTR),three in introns, one in 3′ UTR, and eight in 3′ regulatory region. By the linkage disequilibrium(LD) analysis with Haploview4.1 software, two haplotype blocks were observed that were formed by four and 12 identified SNPs,respectively. Using SAS9.2, we performed single locus-based and haplotype-based association analysis on 24 milk FAs in 1065 Chinese Holstein cows, and discovered that all the SNPs and the haplotype blocks were significantly associated with C6:0, C8:0 and C10:0(P < 0.0001–0.0384). Further, with Genomatix, we predicted that four SNPs in 5′ regulatory region(g.146702957 G > A, g.146704373 A > G, g.146704618 A > G and g.146704699 G > A) changed the transcription factor binding sites(TFBSs) for transcription factors SMARCA3, REX1, VMYB, BRACH, NKX26, ZBED4, SP1, USF1, ARNT and FOXA1. Out of them, two SNPs were validated to impact transcriptional activity by performing luciferase assay that the alleles A of both SNPs, g.146704373 A > G and g.146704618 A > G, increased the transcriptional activities of AGPAT3 promoter compared with alleles G(P = 0.0004).Conclusions: In conclusion, our findings first demonstrated the significant genetic associations of the AGPAT3 gene with milk FAs in dairy cattle, and two potential causal mutations were detected.

The Effect of Dietary Vegetable Oilseeds Supplement on Fatty Acid Profiles in Milk Fat from Lactating Dairy Cows

To determine the effect of dietary supplementation with vegetable oilseeds on the composition of bovine milk fatty acids （FAs）, 40 Holstein dairy cows were used with a complete randomized design. At the beginning of the experiment, the cows were 150±25 day in milk （DIM）. Total duration of the experiment was six weeks. Measurements were made during the last three weeks. Cows in four treatments were fed with a basal diet （CT） or basal diet supplemented with either whole full fat soybean （WFS）, full fat expanded soybean （FPS） or whole full fat soybean with whole cottonseed and full fat expanded soybean （MIX）. The composition of the milk fat was analyzed by gas chromatography. Relative to control, the conjugated linoleic acid （CLA） concentration in milk fat from cows on FPS was significantly increased by 83.88% （P〈 0.05）. The proportions of C12：0 were decreased by 35.7, 35.51, and 38.65% in milk fat from cows on WFS, MIX, and FPS compared with cows on CT. Similar decreases in C 14：0 were 23.83, 24.85, and 31.48% in WFS, MIX, and FPS treatments, respectively. Feeding vegetable oilseeds increased the proportion of healthy FAs （mainly CLA）, whereas decreased the concentratiofi of C12：0 and C14：0. Therefore, milk and dairy products would have higher nutritive and therapeutic value.

The effect of ensiled paulownia leaves in a high-forage diet on ruminal fermentation,methane production,fatty acid composition,and milk production performance of dairy cows

Background:The use of industrial by-products rich in bioactive compounds as animal feeds can reduce greenhouse gas production.Paulownia leaves silage(PLS)was supplemented to dairy cows'diet and evaluated in vitro(Exp.1;Rusitec)and in vivo(Exp.2,cannulated lactating dairy cows and Exp.3,non-cannulated lactating dairy cows).The study investigated the PLS effect on ruminal fermentation,microbial populations,methane production and concentration,dry matter intake(DMI),and fatty acid(FA)proportions in ruminal fluid and milk.Results:Several variables of the ruminal fluid were changed in response to the inclusion of PLS.In Exp.1,the p H increased linearly and quadratically,whereas ammonia and total volatile fatty acid(VFA)concentrations increased linearly and cubically.A linear,quadratic,and cubical decrease in methane concentration was observed with increasing dose of the PLS.Exp.2 revealed an increase in ruminal p H and ammonia concentrations,but no changes in total VFA concentration.Inclusion of PLS increased ruminal propionate(at 3 h and 6 h after feeding),isovalerate,and valerate concentrations.Addition of PLS also affected several populations of the analyzed microorganisms.The abundances of protozoa and bacteria were increased,whereas the abundance of archaea were decreased by PLS.Methane production decreased by 11%and 14%in PLS-fed cows compared to the control in Exp.2 and 3,respectively.Exp.3 revealed a reduction in the milk protein and lactose yield in the PLS-fed cows,but no effect on DMI and energy corrected milk yield.Also,the PLS diet affected the ruminal biohydrogenation process with an increased proportions of C18:3 cis-9 cis-12 cis-15,conjugated linoleic acid,C18:1 trans-11 FA,polyunsaturated fatty acids(PUFA),and reduced n6/n3 ratio and saturated fatty acids(SFA)proportion in milk.The relative transcript abundances of the 5 of 6 analyzed genes regulating FA metabolism increased.Conclusions:The dietary PLS replacing the alfalfa silage at 60 g/kg diet can reduce the methane emission and improve milk quality with greater proportions of PUFA,including conjugated linoleic acid,and C18:1 trans-11 along with reduction of SFA.

Simultaneous Determination of Melamine, Ammelide, Ammeline, and Cyanuric Acid in Milk and Milk Products by Gas Chromatography-tandem Mass Spectrometry

Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography- tandem mass spectrometry （GC-MS/MS）. Methods Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile （10：40：50, V/V/V）. After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring （MRM） with 2, 6-Diamino-4-chloropyrimidine （DACP） being used as an internal standard. Results The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the tour compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% （n=6）. The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. Conclusion This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.

Genetic Variants in the ELOVL5 but not ELOVL2 Gene Associated with Polyunsaturated Fatty Acids in Han Chinese Breast Milk

The present study was designed to examine the contributions of the fatty acid elongase （ELOVL） gene polymorphisms to the levels of polyunsaturated fatty acids （PUFAs） in breast milk. Two hundred and nine healthy Han Chinese mothers were included in the study. Carriers of minor alleles of SNPs （rs2397142 and rs9357760） in ELOVL5 were associated with higher levels of linoleic acid （LA）, dihomo-γ-linolenic acid （DGLA）, arachidonic acid （AA）, docosatetraenoic acid （DTA）, docosahexenoic acid （DHA）, while in rs209512 of ELOVL5 the carriers of minor alleles had lower levels of DTA compared to major homozygote alleles （P ranged from 0.004-0.046）, and genetically explained variability ranged from 3.2% for eicosapentaenoic acid （EPA） to 6.0% for LA. Our findings demonstrated that common variation in ELOVL5 gene encoding rate-limiting enzymes in the metabolism of PUFAs contribute to the PUFAs in breast milk.

Challenges in enriching milk fat with polyunsaturated fatty acids

Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and influence fatty acid profile with longer chain polyunsaturated fatty acids have proven challenging. Several barriers prevent easy transfer of dietary polyunsaturated fatty acids to milk fat including rumen biohydrogenation and fatty acid esterification. The potential for cellular uptake and differences in fatty acid incorporation into milk fat might also have an effect, though this has received less research effort. Given physiological impediments to enriching milk fat with polyunsaturated fatty acids, manipulating the genome of the cow might provide a greater increase than diet alone, but this too may be challenged by the physiology of the cow.

Feeding Polyunsaturated Supplements to Grazing Dairy Cows Improve the Healthy Value of Milk Fatty Acids

The objective of the experiment was to improve the healthy value of milk fatty acids (FA) by feeding sunflower oil (SO) or sunflower seed (SS) combined or not with fish oil (FO) to grazing dairy cows. Four Holstein cows (515 ± 80 kg liveweight) in late lactation (230 days postpartum) fitted with ruminal cannulae were allotted to a 4 × 4 Latin square design with factorial arrangement of treatments: SS = 1.9 kg dry matter (DM)/cow/d of SS;SO = 0.8 kg/cow/d of SO;SS-FO = SS + 0.24 kg/cow/d FO and SO-FO = SO + 0.24 kg/FO. Cows grazed a high quality pasture offered at 11 kg DM/cow/day. After the afternoon milking cows also received 5.6 kg DM/cow of corn silage and during each milking time cracked corn grain (1.3 kg DM/cow) mixed with a mineral-vitamin premix was fed. Oils and SS were introduced via ruminal cannulae and SS was fed roughly grounded. Milk yield tended (p 12:0, 51% for C14:0 and 29% for C16:0. Atherogenicity index (AI) of milk was reduced particularly in SS-FO. Basal concentration of cis-9, trans-11 C18:2 (CLA) in milk was 1.39 g/100g FA and increased (p < 0.05) by 144% across treatments without differences between SS or SO. Feeding FO increased (p < 0.05) milk contents of CLA (2.86 to 3.92 g/100g FA) and linolenic acid. Comparing SO or SS with or without FO showed no changes for neutral detergent fiber (NDF) and crude protein (CP) degradation of pasture. Polyunsaturated fatty acid (PUFA) fed to grazing dairy cows had a marked effect on milk FA profile putatively enhancing its healthy value.

The effects of step-wise improvement of forage combination in total mixed rations on fatty acid profile in the rumen and milk of Holstein cows

Five lactating Holstein cows in a 5×5 Latin square experiment were fed five high-concentrate total mixed rations(TMRs) to investigate the effects of step-wise improvement of forage combination on ruminal and milk fatty acid profiles. The ratio of concentrate to forage was fixed as 61:39, and the step-wise improvement of forage combination was applied as: TMR1, a ration containing corn stover; TMR2, a ration containing corn stover and ensiled corn stover; TMR3, a ration containing ensiled corn stover and Chinese wild ryegrass hay(Leymus chinensis); TMR4, a ration containing the ryegrass hay and whole corn silage; TMR5, a ration containing the ryegrass hay, whole corn silage and alfalfa hay. The TMRs were offered to the cows twice daily at 0700 and 1900 h. The entire experiment was completed in five periods, and each period lasted for 18 days. Diurnal samples of rumen fluids were collected at 0100, 0700, 1300 and 1900 h(day 16); 0300, 0900, 1500 and 2100 h(day 17); and 0500, 1100, 1700 and 2300 h(day 18). The step-wise improvement of forage combination increased energy and crude protein contents and decreased fibre content. As a result, the step-wise improvement of forage combination increased dry matter intake and milk yield(P<0.05). The step-wise improvement increased dietary content of linolenic acid(C18:3 n-3), but did not alter dietary proportions of palmitic acid(C16:0), stearic acid(C18:0), oleic acid(C18:1 cis-9), linoleic acid(C18:2 n-6) and arachidic acid(C20:0). In response to the forage combination, ruminal concentration of C16:0, C18:2 n-6 and C18:3 n-3 linearly increased against their dietary intakes(P<0.10). The step-wise improvement increased milk contents of C10:0, C12:0, C14:0, C16:0, C18:2 n-6 and C18:3 n-3(P<0.10) and decreased milk contents of C18:0 and C18:1 cis-9(P<0.05). Milk yields of C16:0, C18:1 cis-9, C18:2 n-6 and C18:3 n-3 were linearly increased by the increase of these fatty acids in the rumen(R2≥0.79, P<0.05), and milk yields of C18:2 n-6 and C18:3 n-3 were also positively correlated with dietary intake of these fatty acids(R2≥0.85, P<0.05). The step-wise improvement increased the transfer efficiencies from feed to milk for C18:2 n-6 from 11.8 to 14.2% and for C18:3 n-3 from 19.1 to 22.3%. In a brief, along with the step-wise improvement of forage combination, more dietary linoleic and linolenic acids might escape microbial hydrogenation in the rumen and consequently accumulated in milk fat though these fatty acids were present in low concentrations in ruminal fluids. The step-wise improvement of forage combinations could be recommended as a dietary strategy to increase the transfer efficiency of linoleic and linolenic acids from feed to milk.

Effects of lactic acid bacteria-fermented formula milk supplementation on ileal microbiota,transcriptomic profile,and mucosal immunity in weaned piglets

Background:Lactic acid bacteria(LAB)participating in milk fermentation naturally release and enrich the fermented dairy product with a broad range of bioactive metabolites,which has numerous roles in the intestinal health-promot-ing of the consumer.However,information is lacking regarding the application prospect of LAB fermented milk in the animal industry.This study investigated the effects of lactic acid bacteria-fermented formula milk(LFM)on the growth performance,intestinal immunity,microbiota composition,and transcriptomic responses in weaned piglets.A total of 24 male weaned piglets were randomly divided into the control(CON)and LFM groups.Each group consisted of 6 replicates(cages)with 2 piglets per cage.Each piglet in the LFM group were supplemented with 80 mL LFM three times a day,while the CON group was treated with the same amount of drinking water.Results:LFM significantly increased the average daily gain of piglets over the entire 14 d(P<0.01)and the average daily feed intake from 7 to 14 d(P<0.05).Compared to the CON group,ileal goblet cell count,villus-crypt ratio,sIgA,and lactate concentrations in the LFM group were significantly increased(P<0.05).Transcriptomic analysis of ileal mucosa identified 487 differentially expressed genes(DEGs)between two groups.Especially,DEGs involved in the intestinal immune network for IgA production pathways,such as polymeric immunoglobulin receptor(PIGR),were significantly up-regulated(P<0.01)by LFM supplementation.Moreover,trefoil factor 2(TFF2)in the LFM group,one of the DEGs involved in the secretory function of goblet cells,was also significantly up-regulated(P<0.01).Sequenc-ing of the 16S rRNA gene of microbiota demonstrated that LFM led to selective enrichment of lactate-producing and short-chain fatty acid(SCFA)-producing bacteria in the ileum,such as an increase in the relative abundance of Entero-coccus(P=0.09)and Acetitomaculum(P<0.05).Conclusions:LFM can improve intestinal health and immune tolerance,thus enhancing the growth performance of weaned piglets.The changes in microbiota and metabolites induced by LFM might mediate the regulation of the secretory function of goblet cells.

Improving the Quality of Milk Fatty Acid in Dairy Cows Supplemented with Soybean Oil and DHA-Micro Algae in a Confined Production System

The objective was to reduce saturated fatty acids (SFA) and increase conjugated linoleic acid (CLA, cis-9, trans-11 C18:2), α-linolenic (cis-9, cis-12, cis-15 C18:3) and docosahexaenoic (DHA, C22:6) contents in milk from confined dairy cows in order to promote a healthier option. The work was carried out in a commercial farm (Talar) located in Laguna del Sauce, Maldonado (Uruguay). Twenty four cows were assigned to one of two treatments (12 cows per treatment) over a 6 weeks experimental period. Treatments consisted in a control total mixed ration (C-TMR) without supplementary lipids (L) or the same TMR with the addition of 0.144 kg/cow·day of algae and 0.72 kg/cow·day of soybean oil (L-TMR). Chemical composition of the TMR (44.27% DM) averaged 15.94% for crude protein (CP), 38.20% neutral detergent fiber (NDF), 20.36% acid detergent fiber (ADF), 5.56% fat, 5.30% ash and 28.6% nonstructural carbohydrate (NSCH) with 1.81 Mcal/kg of net energy for lactation (NEL). After 39 days of feeding, individual milk samples were collected during three consecutive days. From the total milk collected, 20 ml were immediately used for chemical composition (Milko Scan) and 80 ml for analysis for milk FA profile. From week 3 onwards, milk production (kg/cow·day) resulted higher (P P P = 0.43) on milk protein content (C-TMR = 3.20;L-TMR = 3.07 g/100g). Milk lactose (C-TMR = 4.86, L-TMR = 4.69 g/100g) and urea nitrogen contents (C-TMR = 21.18, L-TMR = 17.33 g/100g) tended (P cow·day, P 12:0 to C16:0 FA averaging 45.19 in C-TMR and 34.74 g/100g in L-TMR (P P 18:1 trans-9) (0.23) and C18:1 trans-10 (0.44) FA increased (P trans-11 C18:1, VA) increased from 1.08 in C-TMR to 2.56 g/100g of FA in L-TMR (P cis-9, trans-11 C18:2) increased (127%) from 0.62 in C-TMR to 1.41 g/100g FA in L-TMR milk. Content of α-linolenic acid resulted 20% higher (P P cis-9 C18:1) resulted higher (P α-linolenic).

An Empirical Study on Microbial Load and Acidity in Raw Milk Produced in Malayer and Nahavand Cities, Iran 2012

Milk is very susceptible for growth and development of many microorganisms because it is rich in nutrients and has suitable condition. Thus, it is very vital to respect sanitary conditions at all stages of production and transport of raw milk. The objective of the present investigation was to determine the total bacterial, and acidity in raw milk from milk collection centers in Malayer and Nahavand cities. 52 milk samples were collected from 13 centers in summer 2012 and were analyzed according to standard methods. None of the raw milk samples under investigation, had superior or grade 1 quality. Only 7.7% of the samples were classified as raw milk with grade 2 quality and 92.3% were non-standard. The mean of microbial total count in base was 3.8 × 107 CFU/ml and average acidity in the samples was 0.163. The city of Tochqhaz and Aliabade-Damagh has the lowest and the highest microbial total count. In general the result of this study showed unsatisfactory conditions of milk in the milk collection centers of the Malayer and Nahavand cities.

Increasing Conjugated Linoleic Acid Content in Milk and Cheese after Supplementing a Blend of Crude Soybean Oil Sediment Combined with Fish Oil to Grazing Dairy Cows

The aim of the work was to improve the healthy value of milk and cheese fatty acids (FA) by feeding a mix of crude soybean oil sediment (CSOS) combined with fish oil (FO) to grazing dairy cows. The CSOS is a by-product commonly discarded after oil extraction containing 3.3% moisture, 6% total ash and 70.7% oil, locally available, comparatively economic and easy to mix with other feed ingredients. The experiment lasted 55 days from September 30th to November 23th 2018 and was carried out at the dairy farm “Gacef” provider of milk to the dairy industrial plant “Capilla Del Señor” (CDS) located at the Villa María City, Córdoba Province, Argentine. A herd of 80 multiparous Holstein cows producing 24 kg-1 milk·cow-1·day-1 was used. The cows grazed an alfalfa and an oat pasture that represented about 47% of total dry matter (DM) intake supplemented at 8.5 kg DM·cow-1·day-1 with a total mixed ration (TMR) composed (DM basis) by cracked corn grain (35.18%), whole plant corn silage (31.98%), pelletized soyben meal (17.99%), the CSOS supplement (13.85%) and FO (0.99%). The TMR was supplied by halves after each milking time in groupal feeders yielding 1.4 kg·cow-1·day-1 of the CSOS and 0.1 kg·cow-1·day-1 of FO. Before the start of lipid supplementation, milk samples (5) were obtained from the farm-tank representing the standar or reference milk (Ref-Milk). After 21 days of supplementary lipid supply, additional milk samples (5) were obtained representing the modified milk (Mod-Milk). Milk samples were analyzed for chemical composition and milk FA profile. At each time, sufficient quantities of both (Ref- and Mod-Milk) were collected for manufacturing six types of cheeses. The results were analyzed through the Student-T test for independent observations. Oil supplementation did not modify (P > 0.05) the chemical composition of milk. Concentration of butyric acid (C4:0) in milk was not affected (P < 0.858). Concentration of total saturated FA (SFAs) in Ref-Milk averaged 58.83 g 100 g-1 FA and was decreased to 49.67 g 100 g-1 FA in Mod-Milk (P < 0.0001). Monounsaturated FA (MUFAs) increased (P < 0.001) from 32.03 g 100 g-1 FA in Ref-Milk to 38.13 g 100 g-1 FA in Mod-Milk (+19.07%) whereas polyunsaturated FA (PUFAs) increased (+36.1%) from 4.71 to 6.41 (P < 0.004). The Mod-Milk showed a significant (P < 0.002) reduction (-15.3% or 5.9 g 100 g-1 FA) for the total concentration of the potentially atherogenic fraction of milk FA (C12:0 to C16:0). The atherogenic index (AI) also decreased (P < 0.012) from 1.98 in Ref-Milk to 1.42 in Mod-Milk (-28.4%). Concentration of vaccenic acid (VA, trans-11 C18:1) in Mod-Milk averaged 7.77 g 100 g-1 FA which represented a 162 % increase (P < 0.0001) over that observed in Ref-Milk (2.95 g 100 g-1). Concentration of conjugated linoleic acid (CLA, cis-9, trans-11 C18:2) in Ref-Milk averaged 1.47 g 100 g-1 FA and showed an important increase (P < 0.002) in the Mod-Milk (3.86 g 100 g-1 FA, +163%). The omega 6/3 ratio resulted lower (P < 0.012) in the Ref-Milk (2.28) compared to the Mod-Milk (2.83). Milk and cheese FA composition were highly correlated (R2 = 0.99, P < 0.0001). The Mod-Cheeses showed similar results in AI, total concentration of SFAs, MUFAs and PUFAs compared to the milk of origin. Differences in FA composition between the cheeses made with the Ref- and Mod-Milk were equivalent to those described for milks. It is concluded that supplementation with a blend of CSOS supplement and FO was an effective way to improve the healthy value of dairy products by reducing contents of SFAs, atherogenic FAs and the atherogenicity index with a concomitant increase in VA and CLA. Modifications induced in the Mod-Milk were recovered in the Mod-Cheeses. The results obtained may help to reduce saturated fat intake and fight or prevent incidence of non-communicable, cardiovascular and chronic diseases.

Determination of the Fatty Acid Profile of Breast Milk from Nursing Mothers in Bungoma County, Kenya

The fatty acid profile in breast milk of nursing mothers who participated in a Cohort for Vitamin A (COVA) study at the fourth and ninth month of lactation was investigated. Breast milk samples were collected by manual expression and stored at - 20°C until analysis. The fat was extracted from the milk and methylated using the American Oil Chemists’ Society (AOCS) Official Methods with modifications. The separation, identification and quantification of the fatty acid methyl esters was performed by gas chromatography coupled with mass spectrometry (GC-MS). Fat contents of human milk increased significantly between the fourth and ninth month of lactation 0.38 and 1.21 mg·mL-1 respectively;P 0.05) than the average percent of the total unsaturated FAs (48.93%). Similarly, at the 9th month the percentage average of the total saturated fatty acids (15.18%) was significantly lower (P < 0.05) than the average percent of the total unsaturated FAs (31.05%). The results obtained in this study demonstrated that the fat content in breast milk significantly increased in the 9th compared to the 4th month of lactation. The fatty profile was also significantly different with the omega 6 being the dominant at the 9th month compared with the omega - 9 being dominant at the 4th month of lactation.

Characterization of Antibacterial Activity and Potential as Probiotic of Lactic Acid Bacteria Isolated from Goat＇s Milk in Algeria

Lactic acid bacteria （LAB） were isolated from goat＇s milk in different north west region of Algeria. A total of 233 isolates were identified as LAB. However, only 11 strains showed excellent inhibition zones on agar when Salmonella lyphimorium ATCC 13311 was used as an indicator for preliminary detection of antagonistic activity. After elimination of inhibition due to acid and H202, Staphylococcus aureus ATCC 25923 was used for secondary screening for antagonistic activity of these 11 strains. It was found that only 9 strains exhibited a good inhibition zones on agar, and all of them could inhibit E. coli ATCC 25921 and Pseudomonas aeruginosa ATCC 27853 as the third and the forth indicators respectively. Lactococcus lactis subsp, cremoris, Lactobacillus casei subsp, casei, Lactobacillus casei subsp, rhamnosus, Streptococcus salivarius subsp, thermophilus and Lactococcus lactis biovar. diacetylactis were the strains that have a good antibacterial activity, survive in the gastrointestinal conditions and were sensible to the majority of the antibiotics. All isolated strains tolerate pH = 2 and high bile salt concentration.

Dominant Lactic Acid Bacteria and Their Antimicrobial Profile from Three Fermented Milk Products from Northern Namibia

The present study focused on the isolation, identification and antimicrobial profile of the dominant lactic acid bacteria from three traditional fermented milk products namely: Omashikwa, Mabisi and Mashini Ghamushikwa from the north-central and north-eastern parts of Namibia. The microbiological and antimicrobial activities of these products fluctuate from one region to another depending on the local indigenous microflora. Omashikwa and Mashini Ghamushikwa fermentation processes involves the addition of Boscia albitrunca root (Omunkuzi) and butter churning. The root contributes to the flavor of the product, increasing the milk fermentation rate and churning. Mabisi is produced by letting the milk to ferment naturally until the water is separated from the whey. The water is then decanted, and the whey is shaken until it is smooth without removal of fat. A total of 180 isolates of Lactic acid bacteria (LAB) were obtained and identified based on their phenotypical characterization. Cell free supernatants (CFS) of the 180 LAB isolates were evaluated for antimicrobial activities against selected food borne pathogens;Escherichia coli ATCC 25,922, Staphylococcus aureus ATCC 25,923, Bacillus cereus ATTC 10,876, Candida famata and Geotrichum klebahnii using the well diffusion assay. Twenty LAB isolates having the highest inhibitory effects were selected for biochemical identification using API 50 kit and these were identified as being;Lactobacillus plantarum (53%), Lactobacillus rhamnosus (29%), Pediococcus pentosaceus (6%), Lactobacillus paracasei ssp. paracasei (6%) and Lactococcus lactic ssp. lactis (6%). Pediococcus pentosaceus showed the highest inhibitory effect on all the indicator strains. This study provides an insight into LAB diversity of unstudied Namibian fermented milk products and reports a potential production of antimicrobial compounds which is significant in the standardization of protective starter cultures which can be used to control fermentation process and shelf life extension of dairy products in Namibia.

Chia (<i>Salvia hispanica</i>L.) Seed Oil Rich in Omega-3 Fatty Acid: A Healthy Alternative for Milk Fat in Ice Milk

Chia seed oil (Salvia hispanica L.) contains polyunsaturated omega-3 fatty acids and natural antioxidants that have many health effects. Consequently, the chief purpose of the present study was the outcome of various attentiveness of chia seed oil on quality and sensory evaluation of ice milk. In treatments T1, T2, T3, and T4, the milk fat was moderately swapped with chia seed oil at 10%, 20%, 30%, and 40%, respectively, and compared with the control treatment (100% milk fat). All treatments were stored at -18°C for 30 days. Samples were analyzed fortnightly and monthly to determine the shelf life during the storage period by acidity and peroxide value. Physicochemical properties of fatty acids, total polyphenols, and total flavonoids of chia seed oil and ice milk samples were determined. Also, the overrun and sensory evaluation of ice milk samples were studied. Results indicated an increase in the absorption of omega-3 fatty acids (linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic “in the samples of” ice milk supplemented with chia seed oil compared with control. Furthermore, there has been an increase in natural antioxidants (total phenolic and total flavonoid contents) levels in the supplemented ice milk samples as compared to control. Furthermore, an increase in the shelf life of the supplemented ice milk samples was also noticed. Generally, fortification of ice milk with chia seed oil increased the concentration of omega-3 fatty acids and also improved the antioxidant properties of ice milk.

Effect of Diet Supplementation with Combinations of Soybean and Linseed Oils on Milk Production and Fatty Acid Profile in Lactating Dairy Ewes

Thirty-six Pampinta ewes were used in a completely randomized design to examine the effectiveness of soybean (SO) and linseed (LO) oils to reduce the concentration of the atherogenic fatty acids (FA) of milk (C12:0 to C16:0) and increase the content of conjugated linoleic (cis-9, trans-11 C18:2) also called rumenic acid (RA) and vaccenic acids (trans-11C18:1, VA). Six ewes per treatment received a Control diet alone (71% alfalfa hay and 29% concentrate) or supplemented (0.24 kg/ewe·day) with pure oils (SO100 or LO100) or their blend at (%) SO75-LO25, SO50-LO50 and SO25-LO75. Milk yield, milk fat content and milk fat secretion were not affected. Milk protein content resulted higher in SO75-LO25, SO50-LO50 and SO25-LO75 without changes in milk protein yield. Total solid content of milk tended (p p p < 0.001) by oils reaching a minimum value of 1.89 in LO100. Feeding polyunsaturated oils at 7% of total dry matter (DM) intake did not affect the productive response of dairy ewes resulting in an effective tool to improve the healthy value of milk fat. The SO50-LO50 blend showed the highest number of healthy changes in milk FA composition.

Isolation, Characterisation and Evaluation of Antiulcerogenic Potentials of Probiotic Lactic Acid Bacteria Isolated from Fermented Milk and Palm Wine against Ethanol-Induced Gastric Ulcer in Mice

Background: Gastric ulcer is one of the most common gastrointestinal diseases with a worldwide prevalence of about 40% in the developed countries and 80% in Africa. Acid inhibitors, anticholinergics, histamine H2-antagonists and antibiotics are commonly used to treat gastric ulcer. However, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors, anticholinergics and histamine H2-antagonists. Therefore, there is an urgent need for approaches to treat and prevent gastric ulcer. One alternative strategy is the use of probiotic lactic acid bacteria. Aim of the study: This study aimed to isolate and characterised probiotic lactic acid bacteria from palm wine and fermented milk, and to evaluate their antiulcerogenic potentials on ethanol-induced gastric ulcer in mice. Methods: Probiotic lactic acid bacteria were isolated from the fermented milk and palm wine using pour plate technique on MRS agar and identified using the 16S r RNA gene sequencing. For functional properties and selection, acid and bile salt tolerance were evaluated based on viable colony count on MRS agar. Two probiotic lactic acid bacteria were selected for in vivo studies. Fifty-four healthy young adult Balb/c mice were randomly divided into 9 groups of 6 mice each. Gastric ulcer was induced in mice using one oral dose of absolute ethanol (10 mL/kg body weight). The probiotic lactic acid bacteria (F1 and F2) at different doses (MF3 = 9 × 108 CFU/mL, MF6 = 1.8 × 109 CFU/mL and MF9 = 2.7 × 109 CFU/mL) and omeprazole (20 mg/kg) (a reference drug) were orally administrated daily for 14 days before ulcer induction. These mice were sacrificed 1hour after induction and the stomach contents were collected for volume and pH determination. The stomachs were subjected to macroscopic, biochemical and histopathological analysis. Results: Among the isolates obtained, two were considered to have the best acid and bile tolerance capacity (viable count > 7.5 logCFU/ml) and were identified as Limosilactobacillus fermentum strain BB101 (F1) and Lactobacillus casei strain 02 (F2). Oral administration of probiotics Lactic acid bacteria F1 and F2 significantly attenuated gastric ulcer as revealed by significant reduction (P Conclusion: The results of this study revealed that palm wine and fermented milk are sources of potential probiotic lactic acid bacteria, that is lactobacillus fermentum strain BB101 and Lactobacillus casei 02 with excellent bile and acid tolerance capacity. Also, these probiotic lactic acid bacteria exhibit gastroprotective effect on ethanol-induced gastric ulcer via antioxidant, enhance gastric ulcer healing, antacids, and anti-secretary effects.

Assessment of Lipid Quality and Composition of Commercial Infant Milk Formulas in Mexico: Emphasis on Trans Fatty Acid Isomers

Objective: To assess the lipid quality focusing on trans fatty acids (TFA) content of standardized milk formulas marketed in Mexico for infants aged from 0 to 36 months. Material and Methods: A total of 27 infant formulas from eight different leading brands were analyzed. Nine of them belonged to stage 1 (age 12 months). Acquired products were treated by duplicate for extraction of total lipid content with the modified Folch method before their expiration date. Fatty acids were esterified in an alkaline medium followed by an acid-catalyzed esterification. Analysis was performed on a gas chromatograph (5890 Series II;Hewlett-Packard, USA) with a flame ionization detector. Results: Thirty-four fatty acids (C8 to C22) were identified. Most products complied with ESPHAGAN compositional requirements. Only one product exceeded the suggested limit (>3%) for TFA. Long chain polyunsaturated fatty acids (LC-PUFAs) content was consistently meager (≈78%), with low amounts of arachidonic (Conclusion: Most milk formulas complied with ESPHAGAN global recommendations. The content of TFA and LC-PUFAs was scarce in the majority of samples.