Milk and açaí berry pulp improve sensorial acceptability of kefir-fermented milk beverage / Leite e polpa de açaí aumentam a aceitabilidade sensorial de uma bebida fermentada por kefir

Kefir grains are a symbiotic biomass (yeast and bacteria) commonly used to produce milk probiotic fermented beverages. The aim of this study was to produce a mixed beverage of whole milk and açaí (Euterpe oleracea) berry pulp fermented by two different kefir cultures: one specific for milk and one specific for sugared water, adapted to milk. Based on the fermentation yield, pH and sensory analysis, the culture adapted to milk obtained the best results in a composition (g 100 g-1) of 70 of whole milk and 30 of açaí berry pulp, at room temperature (~25°C), without agitation and fermented for 24 h. The results obtained by this formulation were an increase of 12% in the kefir biomass, 93% of fermentation yield, pH 5.10 and overall sensory acceptance of 7.05.

Kefir é uma biomassa simbiótica (leveduras e bactérias) comumente aplicada na obtenção de bebidas fermentadas probióticas de leite. O objetivo deste trabalho foi produzir uma bebida fermentada mista de leite integral e polpa de açaí (Euterpe oleracea) a partir de duas culturas diferentes de kefir: uma original de leite e outra original de água açucarada e adaptada ao leite. Com base na conversão, pH e análise sensorial, os melhores resultados foram obtidos com a cultura adaptada na composição (g 100 g-1) de 70% de leite e 30% de polpa de açaí, sem controle de temperatura (temperatura ambiente ~25° C) e sem agitação e por 24 h de fermentação. Esta formulação apresentou 12% de aumento da biomassa, 93% de conversão, pH 5,10 e uma aceitação global de 7,05.

Determinación del índice glucémico y la carga glucémica de productos lácteos fermentados en sujetos adultos sanos, sedentarios y deportistas / Determination of the glycemic index and glycemic load of fermented dairy products in sedentary healthy adults and athletes

Introducción: el índice glucémico (IG) y la carga glucémica (CG) de productos lácteos fermentados (PLF) con lactobacilos puede ser una recomendación útil para pacientes diabéticos y para la población en general. Objetivo: el objetivo del estudio fue medir el IG y la CG de PLF con lactobacilos en sujetos sedentarios y deportistas, y evaluar si existe diferencia entre ellos. Métodos: el estudio se realizó en México (DF) de acuerdo con la ISO26642:210 (Organización Internacional de Normalización). Los participantes fueron: 10 sedentarios y 10 deportistas. Los PLF analizados fueron: Soful, Yakult, Gastroprotect, BeneGastro, Bonacult, Lala Bio 4 y leche descremada con sacarosa (LDS) y la cantidad de alimento que ingirieron dependió de ajustar a 25 g los HC en la porción. Resultados: el IG de la mayoría de los PLF fue bajo para ambos grupos de sujetos; en los deportistas los PLF Yakult y Bonacult presentaron los mayores IG y solo el Yakult puede considerarse como de IG medio para este grupo; estos dos PLF presentaron la menor relación de proteína/HC. La LDS, lácteo con los HC no fermentados, presentó un IG alto para ambos grupos. La CG de los PLF se encontró entre 4 a 7,6 y solo Gastroprotect presentó estadísticamente la menor CG, lo que pudo deberse a su bajo IG, aun cuando su tamaño de ración no fue la menor, entre los PLF. Conclusión: en general los valores de IG y CG de los PLF fueron bajos para ambos grupos. Por tanto, su consumo puede recomendarse en forma moderada. El IG y CG entre productos lácteos con azúcares fermentados y con azúcares no fermentados fueron diferentes (AU)

Introduction: Glycemic Index (GI) and glycemic load (GL) of natural dairy products fermented with lactobacilli may be useful for diabetic patients and the general population. Objective: To measure the GI and GL in natural dairy products fermented with lactobacilli in sedentary individuals and athletes, and seeing if there is any difference between them. Methods: The study was conducted in Mexico City (DF) according to the ISO26642:210, with a group of 10 sedentary individuals and 10 athletes. The GI was determined in the following diary drinkable products, all adjusted to contain 25 g of carbohydrates: Soful, Yakult, Gastroprotect, BeneGastro, Bonacult, Lala Bio 4 and Skimmed milk with sucrose (SMS). Results: The GI of most dairy fermented products were low for sedentary and athletes, but in athletes Yakult and Bonacult showed the highest GI and Yakult’s GI can be considered as medium for these group; these two dairy products had the lowest protein/carbohydrates ratio. SMS, which contain unfermented carbohydrates, had the highest GI in both groups. The GL of dairy fermented products was 4 to 7.6 and only Gastroprotect had statistically the lowest GL, it may be due to its low GI, even its serving size was not the least among dairy fermented products. Conclusion: The GI and GL levels were relatively low for all the dairy products considered on each of the groups studied, therefore the moderate consumption of these can be recommended (AU)

Effect of Aqueous Extract of the Seaweed Gracilaria domingensis on the Physicochemical, Microbiological, and Textural Features of Fermented Milks.

The effects of the Gracilaria domingensis seaweed aqueous extract in comparison with gelatin on the physicochemical, microbial, and textural characteristics of fermented milks processed with the mixed culture SAB 440 A, composed of Streptococcus thermophilus, Lactobacillus acidophilus, and Bifidobacterium animalis ssp. lactis, were investigated. The addition of G. domingensis aqueous extract did not affect pH, titratable acidity, and microbial viability of fermented milks when compared with the control (with no texture modifier) and the products with added gelatin. Fermented milk with added the seaweed aqueous extract showed firmness, consistency, cohesiveness, and viscosity index at least 10% higher than those observed for the control product (P < 0.05). At 4 h of fermentation, the fermented milks with only G. domingensis extract showed a texture comparable to that observed for products containing only gelatin. At 5 h of fermentation, firmness and consistency increased significantly (P < 0.05) in products with only seaweed extract added, a behavior not observed in products with the full amount of gelatin, probably due to the differences between the interactions of these ingredients with casein during the development of the gel network throughout the acidification of milk. The G. domingensis aqueous extract appears as a promising gelatin alternative to be used as texture modifier in fermented milks and related dairy products.

Peptidomic analysis reveals proteolytic activity of kefir microorganisms on bovine milk proteins.

SCOPE: The microorganisms that make up kefir grains are well known for lactose fermentation, but the extent to which they hydrolyze and consume milk proteins remains poorly understood. Peptidomics technologies were used to examine the proteolytic activity of kefir grains on bovine milk proteins. METHODS AND RESULTS: Gel electrophoresis revealed substantial digestion of milk proteins by kefir grains, with mass spectrometric analysis showing the release of 609 protein fragments and alteration of the abundance of >1500 peptides that derived from 27 milk proteins. Kefir contained 25 peptides identified from the literature as having biological activity, including those with antihypertensive, antimicrobial, immunomodulatory, opioid and anti-oxidative functions. 16S rRNA and shotgun metagenomic sequencing identified the principle taxa in the culture as Lactobacillus species. CONCLUSION: The model kefir sample contained thousands of protein fragments released in part by kefir microorganisms and in part by native milk proteases.

Physico-chemical properties and hypoglycaemic activity of fermented milks prepared with Anemarrhena asphodeloides water extracts.

BACKGROUND: In this research, water extract solutions of Anemarrhena asphodeloides (AA) rhizomes were added to reconstituted milk at 5%, 10% and 15% (v/v) to prepare AA fermented milk (AAFM5, AAFM10 and AAFM15). The AAFM10 was selected for investigation of hypoglycaemic activity. RESULTS: Compared with the control fermented milk, titratable acidity values and water-holding capacities of AA fermented milk were increased to different extents, but syneresis values were reduced. The viable counts of Streptococcus thermophilus, Lactobacillus bulgaricus and Bifidobacterium adolescentis were significantly increased, respectively. The blood sugar level of streptozotocin diabetic mice taking AAFM10 was reduced by 14.4%, and the food intake was decreased. The contents of malondialdehyde, blood urea nitrogen, serum creatinine, triglycerides, total cholesterol, and low-density lipoprotein cholesterol were reduced by different degrees, and insulin and total superoxide dismutase were significantly increased. CONCLUSION: AAFM10 had a significant hypoglycaemic effect and improvement in the complications (such as kidney disease and hyperlipemia) in the mouse model of diabetes.

Bioaccessibility study of plant sterol-enriched fermented milks.

The bioaccessibility (BA) of total and individual plant sterols (PS) of four commercial PS-enriched fermented milk beverages (designated as A to D) was evaluated using in vitro gastrointestinal digestion including the formation of mixed micelles. The fat content of the samples ranged from 1.1 to 2.2% (w/w), and PS enrichment was between 1.5 and 2.9% (w/w). ß-Sitosterol, contained in all samples, was higher in samples A and B (around 80% of total PS). The campesterol content was C (22%) > A (7%) > B (5%). Sitostanol was the most abundant in sample D (85%). Stigmasterol was only present in sample C (33%). The greatest BA percentage for total PS corresponded to samples A and B (16-17%), followed by sample D (11%) and sample C (9%). The total BA was not related to the protein, lipid or PS content of the beverages, whereas samples with higher carbohydrates and fiber contents showed lower BA. The BA of the individual PS differed according to the sample considered, and was not related to the PS profile of the sample, thus indicating strong dependency upon the matrix (PS ingredient and other components). Although in vivo studies should be carried out to better assess the functionality of PS in functional foods such as enriched fermented milk beverages, our in vitro study is a useful preliminary contribution to evaluation of the efficacy of these products.

Evaluation of different drying techniques on the nutritional and biofunctional properties of a traditional fermented sheep milk product.

The purpose of this study was to evaluate the effect of solar and freeze drying techniques on the physicochemical, nutritional and biofunctional properties of salted or unsalted Jameed from fermented sheep milk product. The highest yield of Jameed was obtained via the salted-solar drying process. As measured by colorimetry, salted freeze-dried Jameed showed improved consumer characteristics in terms of increased lightness and decreased red and yellow color components. When unsalted Jameed was prepared by solar or freeze drying, additional major peptide bands were detected by SDS-PAGE treatments as compared to the solar or freeze drying of the salted Jameed. Use of salt in the preparation of solar dried Jameed also led to the highest ACE inhibitory activities whereas antioxidant activity was lowest in unsalted solar dried Jameed. The study findings indicate that both greater yield and better overall nutritional and biofunctional properties were associated with solar dried salted Jameed.

Microbiological and physical-chemical characteristics of fermented milk beverages / Características microbiológicas e físico-químicas de bebidas lácteas fermentadas

This study aimed to evaluate some microbiological and physical-chemical characteristics of fermented milk beverages collected at the main supermarkets in Belo Horizonte (MG). 40 samples of the products corresponding to five distinct brands were collected. They were submitted to the following analyses: Most Probable Number (MPN) of total (30ºC) and thermal tolerant coliforms (45ºC), Salmonella spp., coagulase positive Staphylococcus, molds and yeasts, lactic acid bacteria, pH, titratable acidity and contents of moisture, total solids, protein and fat. The analyses were carried out during the last week of shelf life. The microbiological quality of the samples was good and the counts of lactic bacteria were above the minimum established by the official legislation. Streptococcus and Lactobacillus were isolated and identified from the products and Lactobacillus delbrueckii was molecularly identified in three samples. The mean values for the contents of fat and protein, titratable acidity, pH, moisture and total solids ranged from 1.24 to 1.98%; 1.88 to 2.22%; 0.54 to 0.66%; 3.91 to 4.16; 81.18 to 83.25% and 16.75 to 18.82%, respectively. All samples had protein content in agreement with the official legislation.

O objetivo do presente trabalho foi avaliar as características microbiológicas e físico-químicas de bebidas lácteas fermentadas. Foram coletadas 40 amostras de bebidas lácteas fermentadas pertencentes a cinco marcas distintas, em grandes redes de supermercados de Belo Horizonte. Em cada amostra, foram avaliados os seguintes parâmetros: número mais provável de coliformes totais (30ºC), número mais provável de coliformes termotolerantes (45ºC), pesquisa de Salmonella spp., contagem de Staphylococcus coagulase positiva, contagem de bolores e leveduras, contagem total de bactérias lácticas viáveis, umidade, sólidos totais, teor de proteína, teor de gordura, pH e acidez titulável. As análises foram realizadas na última semana do período de validade. As amostras apresentaram qualidade microbiológica satisfatória, bem como contagens totais de bactérias lácticas viáveis superiores ao mínimo estabelecido pela legislação. Streptococcus e Lactobacillus foram identificados em todas as marcas de bebidas lácteas fermentadas analisadas, e em três delas foi possível identificar a espécie Lactobacillus delbrueckii. Os valores médios encontrados para os teores de gordura, proteína, acidez titulável, pH, umidade e sólidos totais variaram de 1,24 a 1,98%, 1,88 a 2,22%, 0,54 a 0,66%, 3,91 a 4,16, 81,18 a 83,25% e 16,75 a 18,82%, respectivamente. Todas as marcas de bebidas lácteas fermentadas apresentaram teor médio de proteína superior ao mínimo preconizado pela legislação.

Changes in soymilk during fermentation with kefir culture: oligosaccharides hydrolysis and isoflavone aglycone production.

The objective of this study was to evaluate the changes in oligosaccharides and isoflavone aglycone content in soymilk during fermentation with commercial kefir culture. Soymilk was fermented with kefir culture at 25 °C for 30 h. The counts of lactic acid bacteria, Lactococcus lactis, Leuconostoc sp and yeasts; measurements of pH, acidity, α-galactosidase and ß-glucosidase activity, sugar and isoflavone contents were performed at the intervals of time. In the fermented soymilk, the lactic acid bacteria counts increased from 7.6 log to 9.1 CFU g(-1), pH reached to 4.9 and lactic acid reached 0.34 g 100 g(- 1). The α-galactosidase was produced (0.016 AU g(-1)) with 100% raffinose and 92% stachyose hydrolysis being observed after the depletion of galactose, glucose and sucrose. Kefir culture produced ß-glucosidase (0.0164 AU g(-1)), resulting in 100% bioconversion of glycitin and daidzin and 89% bioconversion of genistin into the corresponding aglycones. The fermented soymilk presented 1.67 µmol g(-1) of daidzein, 0.28 µmol g(-1) of glicitein and 1.67 µmol g (-1) of genistein.

Effect of Safflower Oil on Concentration of Conjugated Linoleic Acid of Kefir Prepared by Low-fat Milk.

BACKGROUND: Conjugated linoleic acid (CLA) is a special fatty acid in dairy products with unique antioxidant and anti-cancerous effects. Kefir, a milk product, comprises normalized homogenized cow's milk, the fructose and lactulose syrup as well as a symbiotic starter which has improved probiotic characteristics. The study was aimed to discuss patents and to examine the effect of different safflower oil concentrations on CLA content of the kefir drink prepared by low-fat milk. MATERIAL AND METHODS: Safflower oil was added at 0.1, 0.3 and 0.5% (V/V) to low-fat cow's milk and six formulations of kefir samples were prepared. The CLA content of the kefir products was measured at pH=6.0 and pH=6.8 by gas chromatography. Acid and bile tolerance of bacterial microenvironment in the products were also determined. RESULTS: Substitution of natural fat content of milk with safflower oil resulted in proportional increase in the CLA contents of kefir in a dose dependent manner. The highest concentration of CLA was found under 0.5% (V/V) of safflower oil at pH 6.0 and temperature of 37 °C. Adding the Safflower oil into milk used for kefir production, increased CLA content from 0.123 (g/100 g) in pure safflower free samples to 0.322 (g/100 g) in samples with 0.5% (V/V) of safflower oil. CONCLUSION: The current study revealed that substitution of safflower oil with natural fat of cow's milk may help the production of kefir samples with remarkable increase in CLA content of final product.

Anti-obesity activity of the water extract of Lactobacillus paracasei subsp. paracasei NTU 101 fermented soy milk products.

The anti-obesity activity of the water extract of soy milk fermented with Lactobacillus paracasei subsp. paracasei NTU 101 (W101) was investigated. A high-fat diet (HFD) was used to induce obesity in rats, and the effects of daily W101 feeding (8 weeks) were observed. The rats fed the HFD and supplemented with low-dose W101 (LW101, 15 mg per kg body weight per day) or high-dose W101 (HW101, 150 mg per kg body weight per day) had significantly reduced final body weight in comparison with that of the HFD group. W101 decreased the formation of lipid plaques in the aorta, reduced the adipocyte cross-sectional area and diameter, and reduced the levels of CCAAT/enhancer-binding protein ß (C/EBPß), peroxisome proliferator associated receptor γ (PPARγ), and C/EBPα. Regarding lipogenesis regulation in adipocytes, W101 suppressed heparin-releasable lipoprotein lipase (HR-LPL) in adipose tissues and inhibited lipid absorption, thereby reducing lipogenesis. Lactobacillus paracasei subsp. paracasei NTU 101-fermented soy milk may be used to develop health foods that prevent obesity.

Growth Inhibition of Cronobacter sakazakii in Experimentally Contaminated Powdered Infant Formula by Kefir Supernatant.

Kefir is a type of fermented milk containing lactic and acetic acid bacteria and yeast. In this study, we evaluated the antimicrobial activity of kefir supernatant against Cronobacter sakazakii in powdered infant formula (PIF). In a spot-on-lawn test, the growth of 20 C. sakazakii strains, including 10 clinical and 10 food isolates, was completely inhibited in the presence of kefir supernatant. Significant differences in the diameters of inhibition zones were observed upon treatment with kefir compared with the results for Lactobacillus kefiri and Candida kefyr culture supernatants or solutions of lactic and acetic acid and ethyl alcohol in the agar well diffusion test (P < 0.05). The addition of 100 µl of kefir supernatant to 1 ml of nutrient broth completely inhibited the growth of C. sakazakii, as evaluated by spectrophotometry. The antimicrobial activity of kefir supernatant in experimentally contaminated PIF was also tested; we found no viable C. sakazakii cells remaining in PIF rehydrated with 30% kefir supernatant solution for 1 h, demonstrating that the antimicrobial activity of kefir supernatant against C. sakazakii could be applied in real food samples.

Screening of Lactobacillus strains for their ability to produce conjugated linoleic acid in milk and to adhere to the intestinal tract.

Conjugated linoleic acid (CLA) has been shown to provide beneficial effects on health; however, the amount consumed in food is far from that required for the desired effects. Thus, increasing the CLA content in dairy foods through milk fermentation with specific lactic acid bacteria (LAB) offers an interesting alternative. Moreover, some LAB may be able to adhere to the intestinal mucosa and produce CLA through endogenous synthesis. Therefore, the objective of this study was to screen LAB isolates for their ability to produce CLA in skim milk and in simulated gastrointestinal conditions. Additionally, the ability of selected CLA-producing LAB to adhere to the intestinal mucosa in a murine model was assessed. Results showed that of 13 strains of Lactobacillus tested, only 4 were able to produce CLA in skim milk supplemented with linoleic acid (13.44 ± 0.78 to 50.9 ± 0.26 µg/mL). Furthermore, these 4 Lactobacillus strains were able to survive and produce CLA in simulated gastrointestinal conditions and to adhere to the intestinal mucosa of Wistar rats after 7 d of oral inoculation with fluorescently labeled bacteria. Accordingly, these 4 Lactobacillus strains may be used to manufacture fermented dairy foods to increase CLA content, and consumption of these fermented milks may result in CLA produced endogenously by these LAB.

Quality characteristics and plasmin activity of thermosonicated skim milk and cream.

The shelf life of pasteurized milk is limited by heat-stable proteases, which cause gelation and bitter taste upon extended storage of milk. Ultra-high temperature processing inactivates proteases but detrimentally affects milk's sensory quality. An adjunct to pasteurization is desired to extend milk's shelf life while maintaining quality characteristics. In this study, the effects of combined heat and ultrasound (thermosonication) on total plasmin activity and various quality characteristics of skim milk and cream were studied. Thermosonication, at an average power of 115 W (152 µmp-p, where p-p=peak-to-peak amplitude) for 3 min, decreased the total plasmin activity (i.e., plasmin- and plasminogen-derived activity) by nearly 94% in fresh skim milk and cream. Enzyme activity in thermosonicated skim milk samples measured at the end of 30 d was 5- to 10-fold higher than on d 0, but remained stable in thermosonicated cream. Descriptive analysis of odor attributes was conducted for up to 4 wk with 8 trained panelists. No significant differences were observed between the intensities of offensive "eggy" and "rubbery" odor attributes of thermosonicated skim milk and pasteurized commercial skim milk and cream. In addition, lightness (L*) values and viscosity were not adversely affected by thermosonication. Thermosonication decreased the fat globule size in skim milk and cream, and the homogenizing effect increased with treatment time. Thermosonication at average powers of 104 W (133 µmp-p) and 115 W (152 µmp-p) for 1 and 3 min destroyed coliforms and over 99% of the total aerobic bacteria. The total aerobic bacteria counts of thermosonicated skim milk and cream samples were less than 20,000 cfu/mL on d 30. Because thermosonication did not induce off-aromas or viscosity changes but did inactivate microorganisms and protease enzymes, thermosonication may be an appropriate adjunct to pasteurization to extend milk shelf life.

Formation of volatile compounds in kefir made of goat and sheep milk with high polyunsaturated fatty acid content.

This article explored the formation of volatile compounds during the production of kefir from goat and sheep milks with high polyunsaturated fatty acids (PUFA) as a result of feeding animals forage supplemented with maize dried distillers grains with solubles (DDGS). The increased PUFA content of the goat and sheep milks resulted in significant changes to the fermentation process. In particular, apart from an increase in the time taken to ferment sheep milk, fermentation yielded less 2,3-butanedione. The highest quantities of this compound were assayed in kefir produced from goat milk with an increased content of PUFA. An increase of PUFA significantly elevated ethanal synthesis during lactose-alcohol fermentation of sheep milk. Neither the origin of milk (sheep or goat) nor the level of PUFA had any statistical effect on the amount of ethanal assayed during the fermentation of milk and within the finished product. The proportion of l(+)-lactic acid was higher in kefirs produced using goat milk compared with sheep milk and did not depend on the content of PUFA in milk fat. The content of PUFA had a significant effect on the aroma profile of the resulting kefirs. An increase in PUFA content resulted in the loss of whey aroma in goat milk kefirs and the animal odor in sheep milk kefirs, and a creamy aroma became more prevalent in kefirs made from sheep milk.

The composition and functional properties of whey protein concentrates produced from buttermilk are comparable with those of whey protein concentrates produced from skimmed milk.

The demand for whey protein is increasing in the food industry. Traditionally, whey protein concentrates (WPC) and isolates are produced from cheese whey. At present, microfiltration (MF) enables the utilization of whey from skim milk (SM) through milk protein fractionation. This study demonstrates that buttermilk (BM) can be a potential source for the production of a WPC with a comparable composition and functional properties to a WPC obtained by MF of SM. Through the production of WPC powder and a casein- and phospholipid (PL)-rich fraction by the MF of BM, sweet BM may be used in a more optimal and economical way. Sweet cream BM from industrial churning was skimmed before MF with 0.2-µm ceramic membranes at 55 to 58°C. The fractionations of BM and SM were performed under the same conditions using the same process, and the whey protein fractions from BM and SM were concentrated by ultrafiltration and diafiltration. The ultrafiltration and diafiltration was performed at 50°C using pasteurized tap water and a membrane with a 20-kDa cut-off to retain as little lactose as possible in the final WPC powders. The ultrafiltrates were subsequently spray dried, and their functional properties and chemical compositions were compared. The amounts of whey protein and PL in the WPC powder from BM (BMWPC) were comparable to the amounts found in the WPC from SM (SMWPC); however, the composition of the PL classes differed. The BMWPC contained less total protein, casein, and lactose compared with SMWPC, as well as higher contents of fat and citric acid. No difference in protein solubility was observed at pH values of 4.6 and 7.0, and the overrun was the same for BMWPC and SMWPC; however, the BMWPC made less stable foam than SMWPC.

Effect of fermented milk product containing lactotripeptides and plant sterol esters on haemodynamics in subjects with the metabolic syndrome--a randomised, double-blind, placebo-controlled study.

We investigated the effects of fermented milk product containing isoleucine-proline-proline, valine-proline-proline and plant sterol esters (Pse) on plasma lipids, blood pressure (BP) and its determinants systemic vascular resistance and cardiac output. In a randomised, double-blind, placebo-controlled study, 104 subjects with the metabolic syndrome (MetS) were allocated to three groups in order to receive fermented milk product containing (1) 5 mg/d lactotripeptides (LTP) and 2 g/d plant sterols; (2) 25 mg/d LTP and 2 g/d plant sterols; (3) placebo for 12 weeks. Plasma lipids and home BP were monitored. Haemodynamics were examined in a laboratory using radial pulse wave analysis and whole-body impedance cardiography in the supine position and during orthostatic challenge. There were no differences between the effects of the two treatments and placebo on the measurements of BP at home or on BP, systemic vascular resistance index and cardiac index in the laboratory, neither in the supine nor in the upright position. The changes in plasma LDL-cholesterol concentration were - 0.1 (95% CI - 0.3, 0.1 and - 0.3, 0.0) mmol/l in the 5 and 25 mg/d LTP groups, respectively, and +0.1 (95% CI - 0.1, 0.3) mmol/l during placebo (P= 0.024). Both at baseline and at week 12, the increase in systemic vascular resistance during head-up tilt was lower in the 25 mg/d LTP group than in the 5 mg/d LTP group (P< 0.01), showing persistent differences in cardiovascular regulation between these groups. In subjects with the MetS, intake of LTP and Pse in fermented milk product showed a lipid-lowering effect of borderline significance, while no antihypertensive effect was observed at home or in the laboratory.

Study of the effect of different fermenting microorganisms on the Se, Cu, Cr, and Mn contents in fermented goat and cow milks.

The aim of this study was to determine the Se, Cu, Cr, and Mn concentrations of different types of goat- and cow-milk fermented products and evaluate the influence of fermenting bacteria (classical fermenting starters and a probiotic strain) on these concentrations. Atomic absorption spectrometry with hydride generation was used to measure Se and electrothermal atomization to measure Cu, Cr and Mn. Analytical parameters determined in the fermented milks demonstrated that the procedures used were adequate for Se, Cu, Cr, and Mn analyses. Se levels were significantly lower in fermented goat milk products than in fermented cow milk products (p<0.05). Se, Cu, Cr, and Mn levels did not differ as a function of the fermenting bacteria used in commercial fermented goat or cow milks or in the lab-produced goat yoghurt. Given the Se, and Cr intakes for healthy adults, goat and cow yogurts may be important dietary sources.

In vitro digestibility of goat milk and kefir with a new standardised static digestion method (INFOGEST cost action) and bioactivities of the resultant peptides.

The hydrolysis degrees of goat milk and kefir during simulated gastrointestinal digestion and some bioactivities of the resulting peptides after fermentation and digestion were studied. A static in vitro digestion method by the COST FA1005 Action INFOGEST was used and goat milk and kefir were partially hydrolyzed during the gastric phase and had above 80% hydrolysis after duodenal digestion. There were no differences between the digestibility of goat milk and kefir (p > 0.05). Goat milk and kefir displayed about 7-fold antioxidant activity after digestion (p < 0.05). Fermentation showed no effect on the calcium-binding capacity of the samples (p > 0.05), however, after in vitro digestion calcium-binding capacity of the goat milk and kefir increased 2 and 5 fold, respectively (p < 0.05). Digested goat milk and kefir showed a higher dose-dependent inhibitory effect on α-amylase compared to undigested samples (p < 0.05). α-Glucosidase inhibitory activities and in vitro bile acid-binding capacities of the samples were not determined at the studied concentrations.

Characterization of angiotensin-converting enzyme inhibitory activity of fermented milk produced by Lactobacillus helveticus.

Hypertension affects up to 30% of the adult population in most countries. It is a known risk factor for cardiovascular diseases, including coronary heart disease, peripheral artery disease, and stroke. Owing to the increased health awareness of consumers, the application of angiotensin-converting enzyme (ACE)-inhibitory peptides produced by Lactobacillushelveticus to prevent or control high blood pressure has drawn wide attention. A total of 59 L. helveticus strains were isolated from traditional fermented dairy products and the ACE-inhibitory activity of the fermented milks produced with the isolated microorganisms was assayed. The ACE-inhibitory activity of 38 L. helveticus strains was more than 50%, and 3 strains (IMAU80872, IMAU80852, and IMAU80851) expressing the highest ACE-inhibitory activity were selected for further studies. Particularly, the gastrointestinal protease tolerance and thermostability of the ACE-inhibitory activity in the fermented milks were assessed. Based on these 2 criteria, IMAU80872 was found to be superior over the other 2 strains. Furthermore, IMAU80872 exhibited a high in vitro ACE-inhibitory activity at the following fermentation conditions: fermentation temperature at 40°C, inoculation concentration of 1×10(6) cfu/mL, and fermentation for 18h. Finally, by using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry analysis, we observed changes of the metabolome along the milk fermentation process of IMAU80872. Furthermore, 6 peptides were identified, which might have ACE-inhibitory activity. In conclusion, we identified a novel ACE-inhibitory L. helveticus strain suitable for the production of fermented milk or other functional dairy products.