Application of Bifidobacteria as Starter Culture in Whole Wheat Sourdough Breadmaking

Optimizing Lactic Acid Bacteria Proportions in Sourdough to Enhance Antifungal Activity and Quality of Partially and Fully Baked Bread

The organic acids produced by lactic acid bacteria (LAB) during the fermentation of sourdoughs have the ability to reduce the growth of different molds. However, this ability depends on the LAB used. For this reason, in this study, the proportions of different LAB were optimized to obtain aqueous extracts (AEs) from sourdough to reduce fungal growth in vitro, control the acetic acid concentration, and obtain a specific lactic to acetic acid ratio. In addition, the optimized mixtures were used to formulate partially baked bread (PBB) and evaluate the mold growth and bread quality during refrigerated storage. Using a simplex-lattice mixture design, various combinations of Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Lactobacillus acidophilus were evaluated for their ability to produce organic acids and inhibit mold growth. The mixture containing only Lpb. plantarum significantly reduced the growth rates and extended the lag time of Penicillium chrysogenum and P. corylophilum compared with the control. The AEs' pH values ranged from 3.50 to 3.04. Organic acid analysis revealed that using Lpb. plantarum yielded higher acetic acid concentrations than when using mixed LAB. This suggests that LAB-specific interactions significantly influence organic acid production during fermentation. The reduced radial growth rates and extended lag times for both molds compared to the control confirmed the antifungal properties of the AEs from the sourdoughs. Statistical analyses of the mixture design using polynomial models demonstrated a good fit for the analyzed responses. Two optimized LAB mixtures were identified that maximized mold lag time, targeted the desired acetic acid concentration, and balanced the lactic to acetic acid ratio. The addition of sourdough with optimized LAB mixtures to PBB resulted in a longer shelf life (21 days) and adequately maintained product quality characteristics during storage. PBB was subjected to complete baking and sensory evaluation. The overall acceptability was slightly higher in the control without sourdough (7.50), followed by bread formulated with the optimized sourdoughs (ranging from 6.78 to 7.10), but the difference was not statistically significant (p > 0.05). The sensory analysis results indicated that the optimization was used to successfully formulate a sourdough bread with a sensory profile closely resembling that of a nonsupplemented one. The designed LAB mixtures can effectively enhance sourdough bread's antifungal properties and quality, providing a promising approach for extending bread shelf life while maintaining desirable sensory attributes.

Biodiversity and biotechnological properties of lactic acid bacteria isolated from traditional Moroccan sourdoughs

The present study aimed at characterizing lactic acid bacteria (LAB) strains isolated from traditional sourdoughs collected in different regions of Morocco. Isolated strains were firstly identified using Gram staining and catalase reaction test. Presumptive LAB strains were then checked for various phenotypical properties including growth at 45 °C, resistance to NaCl, enzyme production, acidification capacity, diacetyl and exopolysaccharide (EPS) production, and antifungal activity. Finally, selected LAB strains were identified using 16S rDNA sequencing. Results showed that 32.1% of the isolates were thermophilic (45 °C) and 83.9% were resistant to NaCl (6.5%). Moreover, 51.7 and 37.5% were able to produce diacetyl and EPS, respectively. Regarding enzyme production, 55.3 and 7.1% of the isolates showed lipolytic and proteolytic activities, respectively. Low pH values (3.37-3.76) were obtained after 24 h of incubation of LAB strains in de Man, Rogosa and Sharpe (MRS) broth. Antifungal activity test against Aspergillus flavus, Aspergillus niger and Penicillium spp. showed an inhibition rate up to 50%. Bacterial DNA sequencing showed that LAB isolates belong to seven species, chiefly Levilactobacillus brevis, Lentilactobacillus parabuchneri, Lactiplantibacillus plantarum, Pediococcus pentosaceus, Enterococcus hirae, Bifidobacterium pseudocatenulatum, and Companilactobacillus paralimentarius. These findings, for the first time in Moroccan sourdoughs, indicate that the isolated LAB strains have good multifunctional properties and could be suitable as good starters for sourdough bread production under controlled conditions.

Screening and Application of Novel Homofermentative Lactic Acid Bacteria Results in Low-FODMAP Whole-Wheat Bread

FODMAPs are fermentable oligo-, di-, monosaccharides, and polyols. The application of homofermentative lactic acid bacteria (LAB) has been investigated as a promising approach for producing low-FODMAP whole-wheat bread. The low-FODMAP diet is recommended to treat irritable bowel syndrome (IBS). Wheat flour is staple to many diets and is a significant source of fructans, which are considered FODMAPs. The reduction of fructans via sourdough fermentation, generally associated with heterofermentative lactic acid bacteria (LAB), often leads to the accumulation of other FODMAPs. A collection of 244 wild-type LAB strains was isolated from different environments and their specific FODMAP utilisation profiles established. Three homofermentative strains were selected for production of whole-wheat sourdough bread. These were Lactiplantibacillus plantarum FST1.7 (FST1.7), Lacticaseibacillus paracasei R3 (R3), and Pediococcus pentosaceus RYE106 (RYE106). Carbohydrate levels in flour, sourdoughs (before and after 48 h fermentation), and resulting breads were analysed via HPAEC-PAD and compared with whole-wheat bread leavened with baker’s yeast. While strain R3 was the most efficient in FODMAP reduction, breads produced with all three test strains had FODMAP content below cut-off levels that would trigger IBS symptoms. Results of this study highlighted the potential of homofermentative LAB in producing low-FODMAP whole-wheat bread.

Bread Biopreservation through the Addition of Lactic Acid Bacteria in Sourdough

Nowadays, the consumer seeks to replace synthetic preservatives with biopreservation methods, such as sourdough in bread. Lactic acid bacteria (LAB) are used as starter cultures in many food products. In this work, commercial yeast bread and sourdough breads were prepared as controls, as well as sourdough breads with L. plantarum 5L1 lyophilized. The impact of L. plantarum 5L1 on the properties of bread was studied. Antifungal compounds and the impact on the protein fraction by the different treatments in doughs and breads were also analyzed. In addition, the biopreservation capacity of the treatments in breads contaminated with fungi was studied and the mycotoxin content was analyzed. The results showed significant differences with respect to the controls in the properties of the bread and a higher total phenolic and lactic acid content in breads with higher amounts of L. plantarum 5L1. In addition, there was a higher content of alcohol and esters. Furthermore, adding this starter culture produced hydrolysis of the 50 kDa band proteins. Finally, the higher concentration of L. plantarum 5L1 delayed fungal growth and reduced the content of AFB1 and AFB2 compared to the control.

Effects of Bifidobacteria Fermentation on Physico-Chemical, Thermal and Structural Properties of Wheat Starch

Lactic acid bacteria have been considered to be a very important species during sourdough fermentation. In order to explore the effects of bifidobacteria fermentation on thermal, physico-chemical and structural properties of wheat starch during dough fermentation, starch granules were separated from the fermented dough at different fermentation times, including 0 h, 2 h, 6 h, 9 h and 12 h. The results showed that the morphology of starch granules was destroyed gradually as the fermentation time increased, which appeared as erosion and rupture. With the increase in fermentation time, the solubility showed a significant increase, which changed from 8.51% (0 h) to 9.80% (12 h), and the swelling power was also increased from 9.31% (0 h) to 10.54% (12 h). As for the gelatinization property, the enthalpy was increased from 6.77 J/g (0 h) to 7.56 J/g (12 h), indicating a more stable thermal property of fermented starch, especially for the longer fermentation. The setback value was decreased with short fermentation time, indicating that the starch with a longer fermentation time was difficult to retrograde. The hardness of the gel texture was decreased significantly from 50.11 g to 38.66 g after fermentation for 12 h. The results show that bifidobacteria fermentation is an effective biological modification method of wheat starch for further applications.

Quality Parameters of Wheat Bread with the Addition of Untreated Cheese Whey

Τhe present study was carried out to evaluate wheat bread of three different flour compositions prepared by replacing water with untreated cheese whey (WCB). Bread prepared with water was taken as the control (CB). All breads were stored at 24 ± 1 °C for up to 6 days. Microbiological, physicochemical, and sensory analyses were determined as a function of storage time. WCB had lower total viable counts (TVC) (3.81 log cfu/g for CB and 2.78 log cfu/g for WCB on day 2 of storage) and showed delayed mold growth by 1 day (day 4 for CB and day 5 for WCB). WCB also had lower pH (5.91 for CB and 5.71 for WCB on day 0), higher titratable acidity values (TTA) (2.5-5.2 mL NaOH/10 g for CB and 4.5-6.8 mL NaOH/ 10 g for WCB), and higher protein content (PC) (PC 7.68% for CB and 8.88% for WCB). WCB was characterized by a more intense flavor, reduced hardness but similar cohesiveness, springiness, and adhesiveness compared to CB. Based primarily on sensory (appearance/mold formation) data, the shelf life of WCB was 4-5 days compared to 3-4 days for CB stored at 24 ± 1 °C. The proposed use of whey in bread preparation contributes decisively to the environmentally friendly management of whey.

Sourdoughs fermented by autochthonous Lactobacillus strains improve the quality of gluten-free bread

Sourdoughs based on fermentation by lactobacilli have the potential to produce gluten-free maize-based bread with acceptable technological and rheological characteristics, nutritional quality, and more prolonged shelf life. Of the 17 treatments compared (with or without sourdough, and involving single and multiple LAB species), treatments 12C (Lactobacillus brevis, L sanfranciscensis + L. plantarum), and 8C (L. brevis + L. paralimentarius) showed the lowest rate of complex modulus, while treatments 11C (L. sanfranciscensis + L. brevis + L. paralimentarius) and 2C (L. brevis) led to the greatest reduction in baking loss. The crumb moisture content of all of the formulations decreased with storage. Breads produced with treatment 2C (L. brevis) had the highest crumb moisture content when freshly baked, while loaves produced with treatment 3C (L. paralimentarius) had the highest crumb moisture content after four days of storage. A sensory evaluation indicated that sourdough-based maize breads were superior to both control and chemically acidified breads. The optimal treatments were to use sourdough seeded with treatment 2C (L. brevis), with treatment 4C (L. plantarum), with treatment 8C (L. brevis + L. paralimentarius), or with treatment 11C (L. sanfranciscensis + L. brevis + L. paralimentarius).

Isolation and Characterization of Lactic Acid Bacteria and Yeasts from Typical Bulgarian Sourdoughs

Traditional sourdoughs in Bulgaria were almost extinct during the centralized food production system. However, a rapidly developing trend of sourdough revival in the country is setting the demand for increased production and use of commercial starter cultures. The selection of strains for such cultures is based on geographical specificity and beneficial technological properties. In this connection, the aim of this study was to isolate, identify and characterize lactic acid bacteria (LAB) and yeasts from typical Bulgarian sourdoughs for the selection of strains for commercial sourdough starter cultures. Twelve samples of typical Bulgarian sourdoughs were collected from different geographical locations. All samples were analyzed for pH, total titratable acidity and dry matter content. Enumeration of LAB and yeast was also carried out. Molecular identification by 16S rDNA sequence analysis was performed for 167 LAB isolates, and 106 yeast strains were identified by ITS1-5.8S-ITS2 rRNA gene partial sequence analysis. The LAB strains were characterized according to their amylolytic and proteolytic activity and acidification capacity, and 11 strains were selected for further testing of their antimicrobial properties. The strains with the most pronounced antibacterial and antifungal activity are listed as recommended candidates for the development of starter cultures for sourdoughs or other food products.

Characterization of Artisanal Spontaneous Sourdough Wheat Bread from Central Greece: Evaluation of Physico-Chemical, Microbiological, and Sensory Properties in Relation to Conventional Yeast Leavened Wheat Bread

In the present study, both yeast leavened bread (YLB) and artisanal sourdough wheat bread (SDB) were prepared. The physico-chemical, microbiological, and sensory properties of breads were monitored as a function of storage time (T = 25 °C). As expected, the titratable acidity (TA) values of SDB were higher than those of YLB. The aroma profile of SDB was similar to that of YLB, including classes of compounds such as alcohols, aldehydes, ketones, esters, organic acids, terpenes, and sulfur compounds; however, the concentrations between the two were different. Aroma deterioration of bread during storage was partly related to the loss of several volatiles. Texture and sensory analysis showed that SDB was harder, less elastic, but richer in aroma and light sour taste than YLB. Mold growth was apparent when the population of yeasts/molds reached approximately 4 log cfu/g. This yeast/mold count was reached on days 4–5 for YLB and day 18 + for SDB. A 16S amplicon meta-barcoding analysis showed that the bacterial profile of SDB was dominated by a single genus, (Lactobacillus). Analysis of the eukaryotic load showed that at the genus level, Saccharomyces and Alternaria were the most abundant genera, independently of the gene sequenced (18S or ITS). Based primarily on mold growth and texture data, which proved to be the most sensitive quality parameters, the shelf life was ca. 4–5 days for YLB and 10 days for SDB.

Effect of Short Fermentation Times with Lactobacillus paracasei in Rheological, Physical and Chemical Composition Parameters in Cassava Dough and Biscuits

Dough fermentation with lactic acid bacteria has been extensively studied due to the associated health benefits and its effects on physical and rheology parameters in dough and bread. However, most of the studies rely on long fermentation times. The aim of this study is to evaluate the effect of short fermentation times (0 to 8 h) with Lactobacillus paracasei in rheology, physical and chemical properties on cassava dough and biscuits. Both storage modulus and loss modulus decreased as the fermentation times increased, down to 54,206.67 ± 13,348 and 17,453.89 ± 3691 Pa, respectively. Fermentation with L. paracasei influenced biscuit’s hardness and chemical properties, and gas cell sizes were increased notably. These results suggest that short fermentation times could be used to improve dough’s rheological characteristics.

Effect of fermentation and dry roasting on the nutritional quality and sensory attributes of quinoa

BACKGROUND

Quinoa is a pseudocereal with relatively high content of proteins and minerals that also contains mineral inhibitors such as phytate. The aim of the present study was to evaluate lactic acid fermentation and dry roasting on the nutritional quality and sensory attributes of quinoa. Various processes were evaluated, and quinoa grains were dry-roasted, milled, and fermented, either with or without the addition of wheat phytase or activated quinoa phytase (added as back-slop starter), for 10 hr. In other processes, raw quinoa flour was fermented for 10 hr or 4 hr and dry-roasted. Hedonic sensory evaluation was then performed to evaluate the acceptability of the fermented flours prepared as porridges.

RESULTS

The combined dry roasting and fermentation processes significantly (p < .05) degraded phytate between 30% and 73% from initial content. The most effective process was fermentation of raw quinoa flour followed by dry roasting, which improved the estimated zinc and iron bioavailability. Particularly, estimated zinc bioavailability improved from low (Phy:Zn 25.4, Phy·Zn:Ca 295) to moderate (Phy:Zn 7.14, Phy·Zn:Ca 81.5). Phytate degradation was mainly attributed to the activation of endogenous phytase during fermentation. Dry roasting was effective in improving the sensory attributes of the fermented quinoa flour. Porridge made with raw quinoa flour fermented for 4 hr and dry-roasted was more favorable to overall acceptability than that which was fermented for 10 hr and dry-roasted.

CONCLUSION

Fermentation of quinoa flour for 4 hr followed by dry roasting was successful in improving both nutritional and sensory attributes of the final product.

Fermentation of pseudocereals quinoa, canihua, and amaranth to improve mineral accessibility through degradation of phytate

BACKGROUND

Pseudocereals are nutrient-rich grains with high mineral content but also phytate content. Phytate is a mineral absorption inhibitor. The study's aim was to evaluate phytate degradation during spontaneous fermentation and during Lactobacillus plantarum 299v® fermentation of quinoa, canihua, and amaranth grains and flours. It also aimed to evaluate the accessibility of iron, zinc, and calcium and to estimate their bioavailability before and after the fermentation of flours with starter culture. Lactic acid, pH, phytate, and mineral content were analyzed during fermentation.

RESULTS

Higher phytate degradation was found during the fermentation of flours (64-93%) than during that of grains (12-51%). Results suggest that phytate degradation was mainly due to endogenous phytase activity in different pseudocereals rather than the phytase produced by added microorganisms. The addition of Lactobacillus plantarum 299v® resulted in a higher level of lactic acid (76.8-82.4 g kg^-1 DM) during fermentation, and a relatively quicker reduction in pH to 4 than in spontaneous fermentation. Mineral accessibility was increased (1.7-4.6-fold) and phytate : mineral molar ratios were reduced (1.5-4.2-fold) in agreement with phytate degradation (1.8-4.2-fold) in fermented flours. The reduced molar ratios were still above the threshold value for the improved estimated mineral bioavailability of mainly iron.

CONCLUSION

Fermentation proved to be effective for degrading phytate in pseudocereal flours, but less so in grains. Fermentation with Lactobacillus plantarum 299v® improved mineral accessibility and estimated bioavailability in flours. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Lactobacillus-fermented sourdoughs improve the quality of gluten-free bread made from pearl millet flour

The study investigated the effect of sourdough made from combinations of four Lactobacillus spp. on the physicochemical properties, consumer acceptability, and shelf life of bread made from pearl millet flour. Fermentation based on both single and multiple species reduced the pH of the dough and increased its titratable acidity and H₂O₂ content. The addition of sourdough increased the elasticity and reduced the stiffness of the pearl millet dough. Sourdough fermented with L. brevis had the greatest effect on loaf height, specific volume, porosity, and moisture content. During storage, the moisture content of the bread crumb decreased, but that of their crust increased. Sourdough-based loaves retained their moisture better than conventional loaves and the sourdough suppressed the development of mold for a longer period. An organoleptic assessment showed that the sourdough-based bread was more palatable than either conventional or chemically acidified ones. The tissue softness, chewiness, and flavor of the pearl millet bread decreased during storage. The use of sourdough based on either L. brevis, L. paralimentarius, or L. brevis + L. paralimentarius is recommended to produce high-quality pearl millet-based bread.

Application of Lactobacillus as Adjunct Cultures in Wheat Dough Fermentation

The purpose of this study was to evaluate the potential use of Lactobacillus from traditional Chinese sourdoughs of different regions as original adjunct cultures in the steamed bread making process. The effects of Lactobacillus on dough and steamed bread were evaluated. Some differences were obtained in the parameters of fermented dough (organic acid content, rheofermentative parameters, pH, and total titratable acidity [TTA]) and steamed bread (hardness, specific volume, organic acid content, shape, color, pH, TTA and sensory score) made with five different Lactobacillus strains (Pediococcus pentosaceus, Lactobacillus fermentum, Weissella confusa, Lactobacillus crustorum, and Pediococcus acidilactici). Steamed bread made with P. pentosaceus showed a significant increase in specific volume (from 2.19 to 2.41) and a decrease in hardness (from 3,158 g to 2,301 g). Dough leavened by L. fermentum showed significantly higher amounts of lactic acid and acetic acid than dough inoculated with W. confusa, which had values similar to those of the control. The dough fermented by P. pentosaceus exhibited the most gas production (1,811 mL), which is an important index of streamed bread quality. Our research provides a reference for making steamed bread with Lactobacillus. PRACTICAL APPLICATION: Probiotic Lactobacillus is widely used to produce fermenting foods and has been used in bread processing to improve the quality and characteristics of bread. Steamed bread is one of the most popular fermented foods in northern China. However, there is little information about the application of Lactobacillus in Chinese steamed bread. This study explored the potential use of Lactobacillus to improve the characteristics and quality of steamed bread.

Potential functional bakery products as delivery systems for prebiotics and probiotics health enhancers

Several health benefits have been associated to probiotics and prebiotics, most of these are involved in the regulation of the host's gut microbiome. Their incorporation to diverse food products has been done to develop potential functional foods. In the case of bakery products, their incorporation has been seen to improve several technological parameters such as volume, specific volume, texture along with sensorial parameters such as flavor and aroma. Scientific literature in this topic has been divided in three main research branches: nutrition, physical quality and sensory analyzes, however, studies rarely cover all of them. Due to the harsh thermal stress during baking, sourdough technology along with microencapsulation of probiotics, has been studied as an alternative to enhance its nutritional values and increase cell viability, though in few occasions. The potential functional baked goods have maintained acceptable physical characteristics and sensorial acceptability, while in some cases an improvement is seen due to the effect of probiotics and prebiotics. The results obtained from several studies done, have shown the viability of developing functional bakery products by applying prebiotics or probiotics. This could be used as an encouragement for more research to be done in this topic.

Expression of bifidobacterial phytases in Lactobacillus casei and their application in a food model of whole-grain sourdough bread

Phytases are enzymes capable of sequentially dephosphorylating phytic acid to products of lower chelating capacity and higher solubility, abolishing its inhibitory effect on intestinal mineral absorption. Genetic constructions were made for expressing two phytases from bifidobacteria in Lactobacillus casei under the control of a nisin-inducible promoter. L. casei was able of producing, exporting and anchoring to the cell wall the phytase of Bifidobacterium pseudocatenulatum. The phytase from Bifidobacterium longum spp. infantis was also produced, although at low levels. L. casei expressing any of these phytases completely degraded phytic acid (2mM) to lower myo-inositol phosphates when grown in MRS medium. Owing to the general absence of phytase activity in lactobacilli and to the high phytate content of whole grains, the constructed L. casei strains were applied as starter in a bread making process using whole-grain flour. L. casei developed in sourdoughs by fermenting the existing carbohydrates giving place to an acidification. In this food model system the contribution of L. casei strains expressing phytases to phytate hydrolysis was low, and the phytate degradation was mainly produced by activation of the cereal endogenous phytase as a consequence of the drop in pH. This work shows the capacity of lactobacilli to be modified in order to produce enzymes with relevance in food technology processes. The ability of these strains in reducing the phytate content in fermented food products must be evaluated in further models.

Utilization of a maltotetraose-producing amylase as a whole wheat bread improver: dough rheology and baking performance

A maltotetraose-producing enzyme (G4-amylase) was utilized to improve the baking performance of whole-grain wheat flour. Whole-grain bread dough prepared with G4-amylase showed reduced water absorption and increased development time, while the dough stability was not affected. Also, the G4-amylase-treated samples exhibited lower Mixolab torque values than the control upon heating and cooling. Rheological measurements showed the decreased ratio of Rmax /E and increased tan δ, clearly demonstrating that the viscous characteristics of whole-grain bread dough became dominant with increasing levels of G4-amylase. The use of G4-amylase produced whole-grain wheat breads with a variety of maltooligosaccharides, primarily maltotetraose that positively contributed to the bread volume (1.2-fold higher than the control). Moreover, G4-amylase delayed the crumb firming of whole-grain wheat bread during a 7-d storage period, showing that it can function as an antiretrogradation agent to enhance the quality attributes of whole-grain wheat bread.

Application of bifidobacterial phytases in infant cereals: effect on phytate contents and mineral dialyzability

Phytase activity was recently described in probiotic bifidobacterial strains, opening the possibilities for their use in foods, due to the generally regarded as safe/qualified presumption of safety status of these bacteria. Two raw materials for infant cereals (multicereal and gluten-free) were examined by measuring the myo-inositol phosphates content and the in vitro Ca, Fe, and Zn availability after a dephytinization process with purified phytases from Bifidobacterium longum spp. infantis and Bifidobacterium pseudocatenulatum. Treatment with both enzymes reduced the contents of phytate as compared to control samples (untreated or treated with fungal phytase) and led to increased levels of myo-inositol triphosphate. Dephytinization followed by an in vitro model of intestinal digestion increased the solubility of Zn. However, phytase treatment did not increase significantly the mineral dialyzability as compared to untreated samples. This is the first example of the application of purified bifidobacterial phytases in food processing and shows the potential of these enzymes to be used in products for human consumption.

Novel phytases from Bifidobacterium pseudocatenulatum ATCC 27919 and Bifidobacterium longum subsp. infantis ATCC 15697

Two novel phytases have been characterized from Bifidobacterium pseudocatenulatum and Bifidobacterium longum subsp. infantis. The enzymes belong to a new subclass within the histidine acid phytases, are highly specific for the hydrolysis of phytate, and render myo-inositol triphosphate as the final hydrolysis product. They represent the first phytases characterized from this group of probiotic microorganisms, opening the possibilities for their use in the processing of high-phytate-content foods.

Assessment of iron bioavailability in whole wheat bread by addition of phytase-producing bifidobacteria

In this study, the influence of phytase-producing Bifidobacterium strains during the breadmaking process (direct or indirect) on final bread Fe dialyzability and ferritin formation in Caco-2 cell as a measure of cell Fe uptake was assessed. The addition of bifidobacteria significantly reduced the InsP(6) + InsP(5) concentrations compared to control samples. Fe-dialyzable contents for samples with bifidobacteria were increased 2.3-5.6-fold, and dialyzability was improved by 2.6-8.6% compared to controls. However, this was not reflected in an increase of Fe uptake by Caco-2 cells as was predicted by the phytate/Fe molar ratios. The results demonstrated the usefulness of phytase-producing bifidobacteria to reduce phytate during the breadmaking process and to increase Fe accessibility, although the effects appeared to be still insufficient to improve Fe bioavailability in Caco-2 cells. Further refinement of the use of phytase-producing bifidobacterial strains and/or breadmaking technological processes is deserved for improving Fe uptake.