Use of Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris isolated from TRFM in manufacturing of functional low-fat cheeses

Abstract: The purpose of this study was to manufacture new functional low‐fat cheeses using Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris strains isolated from TRFM. After 28 d of ripening and storage, the viable populations of lactic acid bacteria (LAB) in the low‐fat cheeses made with L. lactis subsp. cremoris TL1 (TL1), L. lactis subsp. cremoris TL4 (TL4), and TRFM still maintained above 10⁸ CFU/g. The low‐fat cheeses made with TL1 and TRFM showed higher moisture contents than the cheeses made with TL4, full‐fat, and low‐fat cheese controls. The low‐fat cheeses made with TL1 and TL4 had higher customer preferential scores similar to full‐fat cheese control in the sensory evaluation. Additionally, the low‐fat cheeses fermented with TL1, TL4, and TRFM for 4 h had higher 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radical‐scavenging and ferrous ion‐chelating abilities than the cheeses fermented with the starters for 8 h, full‐fat, and low‐fat cheese controls. A better angiotensin‐converting enzyme (ACE) inhibition activity was also observed in the low‐fat cheeses made with TL1, TL4, and TRFM than that in the full‐fat and low‐fat cheese controls during ripening and storage period. Practical Application: As health‐conscious consumers continue to seek low‐fat alternatives in their diets, there remain strong interests for the dairy industry to develop low‐fat cheeses to meet the demands. This study clearly demonstrated that the low‐fat cheeses fermented with TL1 for 4 h showed a better overall acceptability and possessed antioxidative abilities and ACE inhibitory activities than other cheeses tested in this study. By improving its flavor and investigating the possible mechanisms of its functionalities in the future, this low‐fat cheese might possibly be commercialized and give a positive impact on cheese consumption in the future.     

ACE-inhibitory activity and gamma-aminobutyric acid content of fermented skim milk by <Emphasis Type="Italic">Lactobacillus helveticus</Emphasis> isolated from Xinjiang koumiss in China

Eighty-one strains of Lactobacillus were isolated from the koumiss collected in Xinjiang, China. The strains were cultivated in skim milk medium, ACE inhibitory activity and GABA concentrations in the culture supernatants were measured. Screening results revealed that ACE inhibitory activity of 16 strains was higher than 50% and two strains produced GABA. The Lactobacillus—ND01 strain produces both the high ACE inhibitory activity and GABA. The sequence of 16S rDNA of the Lactobacillus—ND01 showed 99% homology to L. helveticus. The first identification of the newly isolated Lactobacillus—ND01 strain which produces both high ACE inhibitory activity and GABA revealed differences from reported species in our study. The L. helveticus ND01 was resistant to acidic condition. The results suggest that L. helveticus ND01 showed good potential for application in the management of hypertension.     

Applicability of bacteriocin‐producing Lactobacillus plantarum,Enterococcus faecium and Lactococcus lactis ssp. lactis as adjunct starter in Minas Frescal cheesemaking

The antimicrobial and technological characteristics of three bacteriocinogenic cultures used as adjunct starters in Minas Frescal cheese were investigated. The cheeses were manufactured with 1% commercial lactic starter and 0.5%Lactococcus lactis ssp. lactis ATCC 11454, Lactobacillus plantarum ALC 01 or Enterococcus faecium FAIR‐E 198. The cheeses were then artificially inoculated with Listeria monocytogenes Scott A, Staphylococcus aureus ATCC 27154 and Bacillus cereus K1‐B041 and stored for 21 days at 8°C. The results show that there was no significant difference in the counts of L. monocytogenes and S. aureus between the cheeses made with added bacteriocinogenic cultures and the control cheese. On the other hand, B. cereus exhibited susceptibility to Lb. plantarum ALC 01 and E. faecium FAIR‐E 198 from the seventh day of storage. However, these cultures increased the proteolysis of the Minas Frescal cheese.     

Effects of fermentation conditions on the potential anti‐hypertensive peptides released from yogurt fermented by Lactobacillus helveticus and Flavourzyme®

This study investigates the effects of fermentation conditions on the production of angiotensin‐converting enzyme inhibitory (ACE‐I) peptides in yogurt by Lactobacillus helveticus 881315 (L. helveticus) in the presence or absence of Flavourzyme^®, which is derived from a mould, Aspergillus oryzae and used for protein hydrolysis in various industrial applications. Optimal conditions for peptides with the highest ACE‐I activity were 4% (v/w) inoculum size for 8 h without Flavourzyme^® supplementation, and 1% inoculum size for 12 h when combined with Flavourzyme^®. The yogurt fermented by L. helveticus resulted in IC₅₀ values (concentration of inhibitor required to inhibit 50% of ACE activity under the assayed conditions) of 1.47 ± 0.04 and 16.91 ± 0.25 mg mL^?1 with and without Flavourzyme^® respectively. Seven fractions of ACE‐I peptides from the yogurt incorporated with L. helveticus and Flavourzyme^® were separated using the preparative high‐performance liquid chromatography. Fraction (F3) showed the highest ACE‐I activity with an IC₅₀ of 35.75 ± 5.48 μg mL^?1. This study indicates that yogurt may be a valuable source of ACE‐I peptides, which may explain the outcomes observed in the experimental and clinical studies and foresee the application of fermented milk proteins into functional foods or dietary supplements.     

Effect of seaweed flakes addition on the development of bioactivities in functional Camembert‐type cheese

The effect of adding Palmaria palmata or Saccharina longicruris to Camembert‐type cheese on both the antioxidant capacity (ORAC) and Angiotensin I‐converting enzyme (ACE)‐inhibitory activity has been studied with the aim of developing a functional food. The nutritional composition showed that P. palmata had the highest total protein and carbohydrate contents while S. longicruris demonstrated the highest total fibre and minerals contents. The bioactivities determined in the S. longicruris soluble extract were the highest. Three cheese model curds were studied: cheese control (CC), 2% of P. palmata (C2PP) and 2% of S. longicruris (C2SL). During ripening (20 days), the curd pH of all treatments was significantly similar, as their ORAC values, starting at 0 and reaching 41.28 mmol TE g^?1. The ACE‐inhibitory activity of the three treatments was significantly similar, at day 0 (13.20%) and day 20 (58.27%). The feasibility of including these two seaweeds into Camembert‐type cheeses was validated through the adequate development of bioactivities during ripening supporting promising food applications.     

Influence of adjunct cultures on angiotensin‐converting enzyme (ACE)‐inhibitory activity,organic acid content and peptide profile of kefir

The angiotensin‐converting enzyme (ACE)‐inhibitory activities, peptide profiles and organic acid contents in kefir produced by kefir grains plus lactic acid bacteria as adjunct cultures were determined. All the kefir samples showed almost similar peptide profiles as detected by RP‐HPLC, but quantitative differences were observed during storage. The ACE‐inhibitory activities of different lactic cultures did not exhibit a linear tendency during storage period. After 7 days of storage, there was a significant increase in ACE‐inhibitory activity of the sample fermented with Lactobacillus helveticus. However, a kefir sample containing Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis exhibited a higher ACE‐inhibitory activity (92.23%) compared to the other samples.     

Proteolysis of Hispanico cheese manufactured using lacticin 481-producing Lactococcus lactis ssp. lactis INIA 639

Hispánico cheese was manufactured using lacticin 481-producing Lactococcus lactis ssp. lactis INIA 639, bacteriocin-nonproducing L. lactis ssp. lactis INIA 437, or a combination of both strains, as starter cultures. Lactobacillus helveticus LH 92, a culture of high amino-peptidase activity sensitive to lacticin 481, was added to all vats. Milk inoculation with the bacteriocin producer promoted early lysis of Lb. helveticus cells in cheese. Cell-free aminopeptidase activity in cheese made with the 3 lactic cultures was 1.8 times the level reached in cheese made only with L. lactis strain INIA 437 and Lb. helveticus, after 15 d of ripening. Proteolysis (as estimated by the o-phthaldialdehyde method) in cheese made with the 3 lactic cultures was twice as high, and the level of total free amino acids 2.4 times the level found in cheese made only with L. lactis strain INIA 437 and Lb. helveticus, after 25 d of ripening. Hydrophobic and hydrophilic peptides and their ratio were at the lowest levels in cheese made with the 3 lactic cultures, which received the lowest scores for bitterness and the highest scores for taste quality.     

Differentiation of intracellular peptidases of starter and adjunct cultures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Selection of starter and adjunct cultures is important to minimize bitterness of Cheddar and Gouda cheeses. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry may be useful for rapid screening of cheese cultures for propensity to produce bitter cheese. The objective of this study was to demonstrate the application of MALDI-TOF for differentiating intracellular peptidase activities of starter and adjunct cultures on β-CN f193-209 under simulated cheese condition. Bovine β-casein was incubated with chymosin in 9.55 g/l citrate buffer (pH 5.4, 40 g/l sodium chloride) at 30°C for 24 h, followed by incubation with cell-free extract (CFE) of starter or adjunct culture. Mixed strains of Lactococcus lactis ssp. lactis and L. lactis ssp. cremoris designated as 56 and 105 were the sources of nonbitter and bitter starter cultures, respectively. Lactobacillus helveticus WSU-19 and W900R represented adjunct cultures having high and low debittering activities, respectively. The degradation pattern of β-CN f193-209 by CFE of WSU-19 indicates general aminopeptidase and endopeptidase activities, while degradation of the peptide by CFE of W900R, 56, and 105 are mainly from endopeptidase activity. The rates of β-CN f193-209 hydrolysis by CFE of WSU-19, W900R, 56, and 105 are 6.90, 0.38, 0.39, and 0.23 mg/l per h, respectively.     

Influence of exopolysaccharide‐producing cultures on the volatile profile and sensory quality of low‐fat Tulum cheese during ripening

The objective of this investigation was to compare the composition and changes in the concentration of volatiles in low‐fat and full‐fat Tulum cheeses during ripening. Tulum cheese was manufactured from low‐ or full‐fat milk using exopolysaccharide (EPS)‐producing or non‐EPS‐producing starter cultures. A total of 82 volatile compounds were identified belonging to the following chemical groups: acids (seven), esters (21), ketones (14), aldehydes (six), alcohols (14) and miscellaneous compounds (20). The relative amounts of acids, alcohols and aldehydes increased in the cheeses made with EPS‐producing cultures during 90 days of ripening. Differences were found in the volatile profile of full‐fat Tulum cheese compared with the low‐fat variant, especially after 90 days of ripening. Exopolysaccharide‐producing cultures changed the volatile profile, and the EPS‐producing cultures including Streptococcus thermophilus + Lactobacillus delbrueckii subsp. bulgaricus + Lactobacillus helveticus (LF‐EPS2) produced cheese with higher levels of methyl ketones and aldehydes than the non‐EPS cultures. In the sensory analysis, full‐fat Tulum cheeses and the cheese produced with the EPS‐producing culture containing Lb. helveticus (LF‐EPS2) were preferred by the expert panel. It was concluded that the use of EPS‐producing starter cultures in the manufacture of low‐fat Tulum cheese had the potential to improve the flavour.     

Microbial dynamics during the ripening of a mixed cow and goat milk cheese manufactured using frozen goat milk curd

To overcome the seasonal shortage of goat milk in mixed milk cheese manufacture, pasteurized goat milk curd and high-pressure-treated raw goat milk curd manufactured in the spring were held at −24°C for 4 mo, thawed, and mixed with fresh cow milk curd for the manufacture of experimental cheeses. Control cheeses were made from a mixture of pasteurized cow and goat milk. The microbiota of experimental and control cheeses was studied using culture-dependent and culture-independent techniques. Bacterial enumeration by classical methods showed lactic acid bacteria to be the dominant population in both control and experimental cheeses. In total, 681 isolates were grouped by partial amplified rDNA restriction analysis (ARDRA) into 4 groups and identified by 16S rRNA gene sequencing as Lactococcus lactis ssp. lactis (563 isolates), Leuconostoc pseudomesenteroides (72 isolates), Lactobacillus spp. (34 isolates), and Lc. lactis ssp. cremoris (12 isolates). Temporal temperature gradient gel electrophoresis (TTGE) analysis of cheese showed (1) the predominance of Lc. lactis in all cheeses; (2) the presence of Leu. pseudomesenteroides population in all cheeses from d 15 onward; (3) the presence of a Lactobacillus plantarum population in control cheese until d 15 and in experimental cheeses throughout the ripening period. Due to the most diverse and complete set of peptidases present in the genus Lactobacillus, the prevalence of this population in experimental cheeses could give rise to differences in cheese flavor between experimental and control cheeses.     

Effect of Flavourzyme® on Angiotensin‐Converting Enzyme Inhibitory Peptides Formed in Skim Milk and Whey Protein Concentrate during Fermentation by Lactobacillus helveticus

Angiotensin‐converting enzyme inhibitory (ACE‐I) activity as affected by Lactobacillus helveticus strains (881315, 881188, 880474, and 880953), and supplementation with a proteolytic enzyme was studied. Reconstituted skim milk (12% RSM) or whey protein concentrate (4% WPC), with and without Flavourzyme^® (0.14% w/w), were fermented with 4 different L. helveticus strains at 37 °C for 0, 4, 8, and 12 h. Proteolytic and in vitro ACE‐I activities, and growth were significantly affected (P < 0.05) by strains, media, and with enzyme supplementation. RSM supported higher growth and produced higher proteolysis and ACE‐I compared to WPC without enzyme supplementation. The strains L. helveticus 881315 and 881188 were able to increase ACE‐I to >80% after 8 h of fermentation when combined with Flavourzyme^® in RSM compared to the same strains without enzyme supplementation. Supplementation of media by Flavourzyme^® was beneficial in increasing ACE‐I peptides in both media. The best media to release more ACE‐I peptides was RSM with enzyme supplementation. The L. helveticus 881315 outperformed all strains as indicated by highest proteolytic and ACE‐I activities.     

The effects of incorporating wild‐type strains of Lactococcus lactis into Turkish white‐brined cheese (Beyaz peynir) on the fatty acid and volatile content

The development of free fatty acids (FFA) and volatile flavour compounds in the Turkish white‐brined cheese Beyaz peynir made by using three wild strains of Lactococcus lactis subsp. lactis was investigated over 90 days. Results showed that production of both FFA and flavour compounds in the control (PK1) and experimental cheeses (MBLL9, MBLL23 and MBL27) was strain dependent. The hydrolysis of milk fat was more evident in the cheese made using Lc. lactis subsp. lactis MBL27. Considering the production of fat breakdown compounds and acidification activities of the strains MBLL23 and MBL27, the combination of these strains could be proposed for the production of white‐brined cheese.     

Effects of Wild-Type Starter Culture (Artisanal Strains) on Volatile Profile of Urfa Cheese Made from Ewe Milk

In the present study, the development of volatile flavor compounds in sheep’s milk Urfa cheese made by using three different combinations of wild-type strains including Lactococcus lactis subsp. lactis 1B4, Lactococcus garvieae IMAU 50157, Enterococcus faecium ATCC 19434, Enterococcus durans IMAU 60200, and Enterococcus faecalis KLDSO.034 was investigated over 180 days. Three batches of cheese were made using above strains as follows: Cheese A (strains ATCC 19434+1B4+IMAU 50157); Cheese B (strains IMAU 60200+ATCC 19434+1B4); Cheese C (strains KLDSO.034+ IMAU 60200+ ATCC 19434+1B4+ IMAU 50157). The fourth batch was produced from raw sheep’s milk as control (Cheese D). The volatile compounds were identified using a gas chromatography/mass spectrometry system combined with solid-phase microextraction. In total, 70 volatile compounds were recovered from the cheeses including 10 alcohols (mainly ethanol, 2-methyl-1-propanol, 3-methyl-1-propanol), 20 aldehydes and ketones (mainly 2-pentanone, 2-heptanone), 11 esters (mainly ethyl acetate), 10 acids (mainly acetic acid, 2-hydroxy-4-methyl pentanoic acid), 6 terpenes (mainly α-pinene), and 13 miscellaneous compounds (mainly 3,7-dimethyl-1,6-octadiene). While total aldehydes concentration in the control cheese was higher than those made from combinations of wild-type strains (Cheeses A to C), the concentration of alcohols was lower in the former sample. Regarding other volatile compounds there was no clear differences between the cheeses. Results showed that strain combination A or C (Cheese A or C, respectively) could be employed in the manufacture of Urfa cheese made from pasteurized sheep’s milk. However, to reach a fair judgement on the proper strain combination for Urfa cheese, aroma profile (i.e., active compounds) released by the strains should be laid open in detail.     

Effect of a nisin-producing lactococcal starter on the late blowing defect of cheese caused by Clostridium tyrobutyricum

Clostridium tyrobutyricum causes swelling, cracks and off-flavours of cheeses (late blowing defect, LBD) due to butyric acid fermentation. To control this spoilage bacterium, we investigated the use of nisinogenic Lactococcus lactis subsp. lactis INIA 415 as starter in cheeses contaminated with C. tyrobutyricum spores. Control cheese made with spores showed LBD after 14 days of ripening. However, in cheese made with the bacteriocin producer and spores, in which (unlike control cheese) bacteriocin activity was detected throughout ripening, LBD occurred after 21 days. At this stage, level of lactic acid was 1.22-fold higher (P < 0.01) and concentrations of propionic and butyric acids were 2.15- and 2.32-fold, respectively, lower (P < 0.01) in cheese made with the nisin producer than in control cheese, according to the less pronounced spoilage symptoms showed by the former cheese. The bacteriocin producer delayed the appearance of LBD, although it cannot arrest completely C. tyrobutyricum growth.     

Effect of coagulant type and level on the properties of half-salt,half-fat Cheddar cheese made with or without adjunct starter: Improving texture and functionality

The potential of increasing proteolysis as a means of enhancing the texture and heat-induced flow of half-fat, half-salt Cheddar cheese made with control culture (CL, Lactococcus lactis subsp. cremoris/lactis) or adjunct culture (AC, CL + Lactobacillus helveticus) was investigated. Proteolysis was altered by substituting bovine chymosin (BC) with camel chymosin (CC), or by a 2.5-fold increase in level of BC. In cheese with CL-culture, increasing BC led to a large increase in pH and more rapid degradation of α_S1-casein during maturation, and cheese that was less firm after 180 d. In contrast, substitution of BC with CC in cheeses made with CL-culture had an opposite effect. While chymosin type and level had a similar influence on α_S1-casein hydrolysis in the AC-culture cheeses, it did not affect texture or flowability. Grading indicated that cheese made with AC-culture and with a higher level of BC was the most appealing.     

Fate of Listeria monocytogenes in Gouda microcheese: No growth,and substantial inactivation after extended ripening times

This challenge study demonstrates that Listeria monocytogenes does not grow in Gouda cheese: during the first 8 weeks of ripening no growth was observed and between 8 and 52 weeks viable numbers declined significantly in a well-established Gouda microcheese system. Cheese milk was artificially contaminated just prior to addition of the starter culture. Three individual L. monocytogenes strains were used, including strains originating from cheese, a cheese plant environment and a reference strain. During curd formation, viable numbers of L. monocytogenes increased by 0.5 log cfu g⁻¹, resulting from entrapment in the curd. No growth was observed during the first 8 weeks of ripening. A significant decline in the viable numbers of L. monocytogenes was observed in Gouda cheese that was ripened for longer than 8 weeks. Two factors that could possibly control the fate of L. monocytogenes in Gouda cheese were lactic acid and water activity.     

Volatile compounds and aroma of Hispánico cheese manufactured using lacticin 481-producing Lactococcus lactis subsp. lactis INIA 639 as an adjunct culture

Lacticin 481-producing Lactococcus lactis subsp. lactis INIA 639 (BP), bacteriocin-nonproducing L. lactis subsp. lactis INIA 437 (BNP), or a combination of both strains were used as mesophilic cultures for Hispánico cheese manufacture. A Lactobacillus helveticus (LH) culture of high aminopeptidase activity, sensitive to lacticin 481, was used as thermophilic culture. Three batches (BP+LH, BNP+LH, and BNP+BP+LH cheeses) were made in duplicate experiments. Ethanol, 1-propanol, and three ethyl esters reached their highest levels in BP+LH cheese, whereas acetic acid, five ketones, and two alkanes were at their maximum levels in BNP+LH cheese. Higher levels of acetaldehyde and three branched chain aldehydes were found in BNP+BP+LH cheese than in the other two cheeses. Aroma quality and aroma intensity scores were higher for BP+LH and BNP+BP+LH cheeses than for BNP+LH cheese.     

Salt Reduction in a Model High‐Salt Akawi Cheese: Effects on Bacterial Activity,pH, Moisture,Potential Bioactive Peptides,Amino Acids,and Growth of Human Colon Cells

This study evaluated the effects of sodium chloride reduction and its substitution with potassium chloride on Akawi cheese during storage for 30 d at 4 °C. Survival of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum) and starter bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), angiotensin‐converting enzyme‐inhibitory and antioxidant activities, and concentrations of standard amino acids as affected by storage in different brine solutions (10% NaCl, 7.5% NaCl, 7.5% NaCl+KCl [1:1], 5% NaCl, and 5% NaCl+KCl [1:1]) were investigated. Furthermore, viability of human colon cells and human colon cancer cells as affected by the extract showing improved peptide profiles, highest release of amino acids and antioxidant activity (that is, from cheese brined in 7.5% NaCl+KCl) was evaluated. Significant increase was observed in survival of probiotic bacteria in cheeses with low salt after 30 d. Calcium content decreased slightly during storage in all cheeses brined in various solutions. Further, no significant changes were observed in ACE‐inhibitory activity and antioxidant activity of cheeses during storage. Interestingly, concentrations of 4 essential amino acids (phenylalanine, tryptophan, valine, and leucine) increased significantly during storage in brine solutions containing 7.5% total salt. Low concentration of cheese extract (100 μg/mL) significantly improved the growth of normal human colon cells, and reduced the growth of human colon cancer cells. Overall, the study revealed that cheese extracts from reduced‐NaCl brine improved the growth of human colon cells, and the release of essential amino acids, but did not affect the activities of potential bioactive peptides.     

Characterization of the angiotensin-converting enzyme inhibitory activity of fermented milks produced with Lactobacillus casei

Our study assayed angiotensin-converting enzyme (ACE) inhibitory activity and fermentation characteristics of 41 food-originated Lactobacillus casei strains in fermented milk production. Twenty-two of the tested strains produced fermented milks with a high ACE inhibitory activity of over 60%. Two strains (IMAU10408 and IMAU20411) expressing the highest ACE inhibitory activity were selected for further characterization. The heat stability (pasteurization at 63°C for 30 min, 75°C for 25 s, and 85°C for 20 s) and resistance to gastrointestinal proteases (pepsin, trypsinase, and sequential pepsin/trypsinase treatments) of the ACE inhibitory activity in the fermented milks produced with IMAU10408 and IMAU20411 were determined. Interestingly, such activity increased significantly after the heat or protease treatment. Because of the shorter milk coagulation time of L. casei IMAU20411 (vs. IMAU10408), it was selected for optimization experiments for ACE inhibitory activity production. Our results show that fermentation temperature of 37°C, inoculum density of 1 × 10⁶ cfu/g, and fermentation time of 12 h were optimal for maximizing ACE inhibitory activity. Finally, the metabolite profiles of L. casei IMAU20411 after 2 and 42 h of milk fermentation were analyzed by ultra-HPLC electron spray ionization coupled with time-of-flight mass spectrometry. Nine differential abundant metabolites were identified, and 2 of them showed a strong and positive correlation with fermented milk ACE inhibitory activity. To conclude, we have identified a novel ACE inhibitory L. casei strain, which has potential for use as a probiotic in fermented milk production.     

Angiotensin I converting enzyme (ACE) inhibitory activity and antihypertensive effect of fermented milk

Milk was fermented with a total of 25 lactic acid bacteria to assay in vitro inhibitory activity towards angiotensin I converting enzyme (ACE). The tested strains belonged to Lactobacillus acidophilus, Lactobacillus casei, Lacobacillus helveticus, Lactobacillus jensenii, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactococcus lactis ssp. lactis, Lactococcus. raffinolactis and Leuconostoc mesenteroides ssp. cremoris. The ACE inhibitory potencies of theses strains varied and seven of them showing the highest ACE inhibitory activity were selected for further studies. The development of ACE inhibitory activity during fermentation correlated with degree of hydrolysis. Modification of fermentation conditions or pH control did not affect the ACE inhibitory activity. ACE inhibitory compounds from Lb. jensenii fermented milk were isolated by reversed phase HPLC and identified by MS-analysis and amino acid sequencing. The active compounds were peptides from β-casein. The milk fermented with Lb. jensenii caused a transient reduction of blood pressure in spontaneously hypertensive rats.