Quantification of viable Brochothrix thermosphacta in cooked shrimp and salmon by real-time PCR

Brochothrix thermosphacta, a Gram-positive bacterium, is considered as the predominant spoilage microbiota of modified atmosphere packing (MAP) shrimp and fish. Traditional methods currently used to detect B. thermosphacta in foods are time-consuming and labour-intensive. The aim of this study was to develop a real-time PCR quantification method combined with a propidium monoazide (PMA) sample treatment step to monitor the population of B. thermosphacta in cooked shrimp and salmon. The specificity of the two primers MO405 and MO404 used to amplify a 70 bp fragment of the 16S rRNA gene was demonstrated by using purified DNA from 30 strains, among 21 bacterial species including 22 reference strains. Using these primers for real-time PCR and in pure culture, a good correlation was obtained between real-time PCR and the conventional plating method. Quantification was linear over 7-log units using artificially inoculated samples. The method performed successfully when tested on naturally contaminated cooked shrimp and fresh salmon, with a minimum threshold of 1.9×102 CFU/g for accurate quantification of B. thermosphacta. The correlation between the B. thermosphacta counts obtained by real-time PCR and plate counts on naturally contaminated shrimp and salmon was high (R2=0.895). Thus, this study presents a rapid tool for producing reliable quantitative data on B. thermosphacta in cooked shrimp and fresh salmon.     

Control of meatborne Listeria monocytogenes and Brochothrix thermosphacta by a bacteriocinogenic Brochothrix campestris ATCC 43754

The effect of a bacteriocinogenic Brochothrix campestris ATCC 43754 upon the growth of Brochothrix thermosphacta and a 4 strain mixture of Listeria monocytogenes was determined in All Purpose Tween (APT) broth and on pork adipose tissue discs at 4 degrees C. Inocula were prepared to give initial numbers of B. campestris of 6-7 log cfu/ml or cm(2) and 3-4 log cfu/ml or cm(2) of B. thermosphacta and L. monocytogenes. Adipose tissue discs were evaluated by a sensory panel to determine the intensity and acceptability of any off-odours produced during the growth of B. campestris. During co-culture in APT broth with B. campestris the growth of B. thermosphacta or L. monocytogenes was 4 log cycles less than growth in its absence. B. campestris showed limited growth on inoculated pork adipose tissue, increasing from initial numbers of about 6 log cfu/cm(2) to a maximum of 7 log cfu/cm(2) within 7d. B. campestris at numbers of 7 log cfu/cm(2) produced slight off-odours but these were not perceived by the panel as unacceptable. When co-inoculated on adipose tissue discs with B. campestris the numbers of B. thermosphacta or L. monocytogenes was limited to about 2-3 log units less than the numbers attained in its absence. B. campestris ATCC 43754 may be useful for meat preservation because it can inhibit B. thermosphacta and L. monocytogenes in situ while producing little change in the sensory properties of the product.     

In vitro synthesis of biogenic amines by Brochothrix thermosphacta isolates from meat and meat products and the influence of other microorganisms

Twenty Brochothrix thermosphacta strains tested for biogenic amines (BAs) production, formed histamine (6.6-16.2 mg/kg) and tyramine (18.7-35.4 mg/kg) but neither putrescine nor cadaverine. Six of the twenty strains were also investigated in respect of their influence on the synthesis of BAs by Escherichia coli, Pseudomonas sp., Proteus mirabilis and Lactobacillus sakei. In pure culture Escherichia coli produced all of the studied amines (histamine, tyramine, putrescine and cadaverine) with a total concentration of 167.7 mg/kg, P. mirabilis produced a total of 56.7 mg/kg histamine, tyramine and cadaverine, while Lactobacillus sakei and Pseudomonas sp. produced histamine and tyramine, totaling 37.9 and 35.2 mg/kg respectively. All B. thermosphacta promoted cadaverine production by Escherichia coli which increased by 12-68%, and some of them contributed to the appearance of this amine among the metabolites of Pseudomonas. The presence of B. thermosphacta decreased the potential ability of P. mirabilis to produce BAs.     

Technology-induced selection towards the spoilage microbiota of artisan-type cooked ham packed under modified atmosphere

The microbiota associated with a highly-perishable Belgian artisan-type cooked ham was analyzed through plating and (GTG)₅-fingerprinting of isolates throughout its processing chain. The raw tumbled meat was characterized by the presence of a versatile microbiota around 4.8 log(cfu g⁻¹), consisting of lactic acid bacteria, staphylococci, Brochothrix thermosphacta, Gram-negative bacteria, and yeasts. Pasteurisation of the ham logs reduced bacterial counts below 2 log(cfu g⁻¹) and subsequent manipulations selected for leuconostocs and carnobacteria. Also, B. thermosphacta and several Enterobacteriaceae were found at this stage. During storage in an intermediate high-care area for 2 days, a selection towards certain Enterobacteriaceae (Hafnia alvei, Enterobacter spp., and Pantoea agglomerans) and lactic acid bacteria (mainly vagococci and Streptococcus parauberis) was observed. B. thermosphacta, Leuconostoc carnosum and carnobacteria were also detected, but only after allowing bacterial outgrowth by incubating the meat logs at 7 °C for four weeks. After a mild post-pasteurisation process and subsequent handling, incubation of the meat logs at 7 °C for four weeks led to outgrowth of Enterobacteriaceae (mainly Enterobacter spp. and Serratia spp.). B. thermosphacta, and lactic acid bacteria (Enterococcus faecalis, Leuc. carnosum, and Carnobacterium maltaromaticum) were also found. After slicing and packaging under modified atmosphere, the microbiota of the refrigerated end-product consisted of leuconostocs, carnobacteria, and B. thermosphacta.     

Development and validation of an extensive growth and growth boundary model for psychrotolerant Lactobacillus spp. in seafood and meat products

A new and extensive growth and growth boundary model for psychrotolerant Lactobacillus spp. was developed and validated for processed and unprocessed products of seafood and meat. The new model was developed by refitting and expanding an existing cardinal parameter model for growth and the growth boundary of lactic acid bacteria (LAB) in processed seafood (O. Mejlholm and P. Dalgaard, J. Food Prot. 70. 2485–2497, 2007). Initially, to estimate values for the maximum specific growth rate at the reference temperature of 25 °C (μ_ref) and the theoretical minimum temperature that prevents growth of psychrotolerant LAB (T_min), the existing LAB model was refitted to data from experiments with seafood and meat products reported not to include nitrite or any of the four organic acids evaluated in the present study. Next, dimensionless terms modelling the antimicrobial effect of nitrite, and acetic, benzoic, citric and sorbic acids on growth of Lactobacillus sakei were added to the refitted model, together with minimum inhibitory concentrations determined for the five environmental parameters. The new model including the effect of 12 environmental parameters, as well as their interactive effects, was successfully validated using 229 growth rates (μ_max values) for psychrotolerant Lactobacillus spp. in seafood and meat products. Average bias and accuracy factor values of 1.08 and 1.27, respectively, were obtained when observed and predicted μ_max values of psychrotolerant Lactobacillus spp. were compared. Thus, on average μ_max values were only overestimated by 8%. The performance of the new model was equally good for seafood and meat products, and the importance of including the effect of acetic, benzoic, citric and sorbic acids and to a lesser extent nitrite in order to accurately predict growth of psychrotolerant Lactobacillus spp. was clearly demonstrated. The new model can be used to predict growth of psychrotolerant Lactobacillus spp. in seafood and meat products e.g. prediction of the time to a critical cell concentration of bacteria is considered useful for establishing the shelf life. In addition, the high number of environmental parameters included in the new model makes it flexible and suitable for product development as the effect of substituting one combination of preservatives with another can be predicted. In general, the performance of the new model was unacceptable for other types of LAB including Carnobacterium spp., Leuconostoc spp. and Weissella spp.     

The effects of thyme (Thymus vulgaris) and rosemary (Rosmarinus officinalis) essential oils on Brochothrix thermosphacta and on the shelf life of beef packaged in high-oxygen modified atmosphere

The objective of the study was to determine the Minimal Inhibitory Concentration (MIC) of thyme (29.4% thymol, 21.6% p-cymene) and rosemary essential oils (27.6% 1,8-cineole, 13.5% limonene, 13.0% β-pinene) against Brochothrix thermosphacta and to establish the feasibility of their use as components of modified atmosphere during beef refrigerated storage. The minimum inhibitory concentration (MIC) of thyme oil against B. thermosphacta is 0.05% and that of rosemary oil 0.5%. The MIC values are independent on strain and temperature of growth, however the bactericidal effects are strain dependent. The addition of any of oil at a concentration equal to 2MIC to the modified atmosphere (80% O₂/20% CO₂) does not significantly influence the microbial quality of meat. At the same time, such a concentration of the essential oils was considerably detrimental to the organoleptic factors.     

The spoilage characteristics of Brochothrix thermosphacta and two psychrotolerant Enterobacteriacae in vacuum packed lamb and the comparison between high and low pH cuts

The spoilage potential of Brochothrix thermosphacta, Serratia proteamaculans and Rahnella aquatilis was investigated in vacuum packaged high (5.9 to 6.4) and low (5.4 to 5.8) pH lamb. Vacuum packaged fore shank (m. extensor carpi radialis) and striploins (m. longissimus dorsi) (n = 306) inoculated with ~ 100 CFU of individual bacteria were stored for twelve weeks at temperatures − 1.5, 0, 2 and 7 °C. Spoilage characteristics and bacterial numbers were recorded and analysed in comparison to un-inoculated control samples. All three bacterial species were shown to grow in vacuum packaged lamb of pH values between 5.4 and 6.4, when stored at chilled temperatures (− 1.5 to 7 °C) for up to 84 days. B. thermosphacta and S. proteamaculans caused spoilage to the meat under these conditions whilst R. aquatilis spoiled high pH meat at 7 °C. These results go against previous beef models stipulating that Brochothrix and Enterobacteriacae species cannot grow on or cause spoilage of low pH meat in the absence of oxygen.     

Modelling the survival of starter lactic acid bacteria and Bifidobacterium bifidum in single and simultaneous cultures

The inactivation kinetics at 4 degrees C of Bifidobacterium bifidum, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, cultured alone or consociated in a laboratory medium (modified MRS broth), were modelled through the Weibull model and a second-order polynomial equation. The initial cell number of S. thermophilus and L. delbrueckii subsp. bulgaricus was approximately 6-7log (CFU/ml); the viability loss after 30 days of storage was 2.87 and 1.99log (CFU/l) for L. delbruckii subsp. bulgaricus and S. thermophilus, cultured alone, respectively; whereas the consociation of lactobacilli and streptococci with bifidobacteria reduced viability loss during storage (0.28 and 0.54log CFU/l for lactobacilli and streptococci, respectively). Finally, the consociation of lactobacilli and streptococci with B. bifidum improved their oxygen uptake.     

Preservation of porcine blood quality by means of lactic acid bacteria

The capacity of 12 lactic acid bacteria (LAB) strains to preserve porcine blood during storage was evaluated. A general ability of LAB to prevent blood's hemolysis and to maintain the functional properties of plasma was observed. Two strains, PS99 (Enterococcus raffinosus) and TA43 (Lactobacillus reuteri), were selected for studies at 5°C according to their antibacterial activity in blood stored at 15°C. After 144h at 5°C, lower counts of coliforms, Pseudomonas spp., proteolytic and hemolytic bacteria were obtained in blood containing either PS99 or TA43 as compared to the non-inoculated blood. When inulin (2%) was added to blood, higher inhibition values were obtained and Enterococcus raffinosus (PS99) showed the best abilities for blood preservation. On the basis of these results it seems worthwhile to supplement blood with inulin and to inoculate it with an active LAB strain to avoid undesirable changes during chill storage, especially useful to prevent the effects of a cold-chain breakdown.     

Effect of storage temperature and gas permeability of packaging film on the growth of lactic acid bacteria and Brochothrix thermosphacta in cooked meat emulsions

The effect of gas permeability of packaging film on the growth of lactic acid bacteria and Brochothrix thermosphacta in cooked meat emulsions stored at 0, 8 and 15 °C was investigated. The estimated parameters from Gompertz equation for the assayed temperature–oxygen permeability combinations showed LAB development to be significantly greater than those of B. thermosphacta. The influence of the two sources of variation (oxygen permeability of packaging film and temperature) on the growth parameters of LAB and B. thermosphacta was analysed showing a significant effect (P<0.001) of the temperature on both bacterial population while the film permeability had only a significant influence (P<0.001) on B. thermosphacta growth. Under the conditions of this study the packaging film influenced the maximum counts and growth rates of both organisms. Since the inhibition of B. thermosphacta occurred when the meat product was vacuum-packaged in films possessing high oxygen permeability and the effect of pH was found not to be associated with the growth inhibition, accumulation of hydrogen peroxide produced by LAB may possibly be one of the main factors responsible for B. thermosphacta inhibition. Shelf-life of vacuum-packaged cooked meat emulsions in high oxygen transmission rate films will be guarantied and a temperature abuse will not result in an increase of spoilage by LAB.     

Identification of lactic acid bacteria involved in the spoilage of pasteurized “foie gras” products

The spoiling microflora of a re-packaged French “foie gras” product was studied. A total of 54 isolates, originating from two different factories, were identified using phenotypical and molecular methods (partial 16S rDNA sequencing). Weissella viridescens was the main species detected in the products from factory 1 (64% of the isolates). These products had a low lactic acid concentration and were considered as non-spoiled. The microflora of factory 2 was dominated mainly by the genus Lactobacillus (95% of the isolates), and the high lactic acid concentration of these products was linked with a strong spoilage. Among the 30 Lactobacillus strains, three species were predominant: Lactobacillus sakei (nine isolates), Lactobacillus coryniformis (eight isolates) and Lactobacillus paraplantarum (five isolates). Challenge tests were performed to confirm the involvement of the Lactobacillus strains in the spoilage of the product. Sterile “foie gras” samples were inoculated with 14 LAB strains from the collection. The most acidifying strains belonged to the species L. sakei, Lactobacillus plantarum and L. paraplantarum. This confirmed the role of the strains from the Lactobacillus genus as the main spoilers of “foie gras” products and will be useful to design new quality protocols and extend the shelf-life of these products.     

Diversity of lactic acid bacteria from Hussuwa, a traditional African fermented sorghum food

The diversity of lactic acid bacteria associated with Hussuwa fermentation, a Sudanese fermented sorghum food, was studied using a polyphasic taxonomical approach. Predominant strains could be well characterised based on a combination of phenotypic tests and genotypic methods such as ARDRA, rep-PCR and RAPD-PCR, as well as 16S rRNA gene sequencing of representative strains. Thus, the majority (128 of 220, 58.3%) of strains exhibited phenotypic properties typical of heterofermentative lactobacilli and of these, 100 strains were characterised more closely using the genotyping methods. The majority (97/100) strains could be characterised as Lactobacillus fermentum strains. Seventy-two of 220 strains (32.7%) showed phenotypic properties that are characteristic of pediococci. Of 41 selected strains investigated by genotyping techniques, 38 (92.7%) could be characterised as Pediococcus acidilactici strains, while three (7.3%) could be characterised as Pediococcus pentosaceus strains. The Hussuwa fermentation thus appears to be dominated by L. fermentum strains and P. acidilactici strains. For this reason, we selected representative and predominant strains as potential starter cultures for Hussuwa fermentation. These strains, L. fermentum strains BFE 2442 and BFE 2282 and P. acidilactici strain BFE 2300, were shown on the basis of RAPD-PCR fingerprinting to predominate in a model fermentation when used as starter cultures inoculated at 1 × 10⁶ CFU/g and to lower the pH of the fermentation to below pH 4.0 within 48 h. These cultures should be studied for further development as starter preparations in pilot scale studies in actual field fermentations.     

An investigation of the bacteriocinogenic potential of lactic acid bacteria associated with wheat (Triticum durum) kernels and non-conventional flours

One hundred and thirty-seven lactic acid bacteria (LAB), previously isolated from wheat (Triticum durum) grains and non-conventional flour samples, were tested for the production of antibacterial substances. A total of 16 strains (5 Enterococcus faecium, 5 Enterococcus mundtii, 4 Pediococcus pentosaceus, 1 Lactobacillus coryniformis and 1 Lactococcus garvieae) were found to inhibit the growth of Listeria innocua. The antibacterial activities were preliminarily investigated for their general behaviour with proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes, after heat treatment, and exposure to different pHs and ethanol concentrations. Bacteriocin-like inhibitory substances (BLIS) were also characterized for their inhibition spectra against non-pathogenic and pathogenic food-associated and human pathogenic bacteria. LAB showing the best characteristics in terms of inhibition spectrum, inhibition activity and mode of action (bactericidal) belonged to the species Ent. mundtii. The high percentage (11.68%) of BLIS-producing strains detected confirmed previous observations that raw materials may harbour higher numbers of bacteriocinogenic LAB than fermented foods.     

Effect of temperature on the spoilage rate of whole, unprocessed crabs: Carcinus maenas, Necora puber and Cancer pagurus

Shelf life of whole, initially live, crabs depended primarily on the storage conditions and the time at which death occurred. Large differences in the time that individual crab species survived particular storage conditions resulted in wide variations in shelf-life. Bacterial spoilage of Carcinus maenas, Necora puber and Cancer pagurus, measured using aerobic plate counts, indicated that on ice at 4 degrees C whole unprocessed crabs had a shelf life approximately 9-11 days, at 4 degrees C approximately 13-29 days, in simulated supermarket conditions of sale approximately 5-7 days and at 20 degrees C approximately 2-16 days. Storage of whole unprocessed crabs chilled at 4 degrees C considerably extended shelf life compared to crabs stored on ice. Live crabs stored on ice died within 24h, most likely due to thermal shock and their early death was responsible for their more rapid increase in bacterial numbers compared to crabs stored at 4 degrees C. No growth of bacteria occurred in the flesh of live crabs stored at 4 degrees C for between 128 and 504 h. Crab flesh quality deteriorated prior to maximum shelf-life (defined as the time at which bacterial load reached log 5 cfu/g crabmeat) in some instances. The best compromise between high crabmeat yield and long shelf-life is likely to be to transport crabs at 4 degrees C live to market where they could be stored live at 4 degrees C without spoilage for 2 weeks before placed on ice at 4 degrees C, with a potential maximum shelf life of approximately 24 days.     

Isolation and characterization of a nisin-like bacteriocin produced by a Lactococcus lactis strain isolated from charqui,a Brazilian fermented,salted and dried meat product

A Lactococcus lactis subsp. lactis strain (L. lactis 69) capable to produce a heat-stable bacteriocin was isolated from charqui, a Brazilian fermented, salted and sun-dried meat product. The bacteriocin inhibited, in vitro, Listeria monocytogenes, Staphylococcus aureus, several lactic acid bacteria isolated from foods and spoilage halotolerant bacteria isolated from charqui. The activity of the bacteriocin was not affected by pH (2.0–10.0), heating (100 °C), and chemical agents (1% w/v). Treatment of growing cells of L. monocytogenes ScottA with the cell-free supernatant of L. lactis 69 resulted in complete cell inactivation. L. lactis 69 harbored the gene for the production of a nisin-like bacteriocin, and the amino acid sequence of the active peptide was identical to sequences previously described for nisin Z. However, differences were observed regarding the leader peptide. Besides, the isolate was able to survive and produce bacteriocins in culture medium with NaCl content up to 20%, evidencing a potential application as an additional hurdle in the preservation of charqui.     

Comparative evaluation of bacterial cellulose (nata) as a cryoprotectant and carrier support during the freeze drying process of probiotic lactic acid bacteria

Nata or bacterial cellulose produced by Acetobacter xylinum was compared for its cryoprotective and carrier support potential for probiotic lactic acid bacteria against other established cryoprotectants like 10% skim milk, calcium alginate encapsulation or 0.85% physiological saline and distilled water. Individual lactic acid bacteria were grown in MRS broth in the presence of nata cubes or the bacterial suspension mixed with either powdered bacterial cellulose (PBC), 10% skim milk, saline or distilled water and freeze dried. These freeze dried cells were stored at temperatures of either 30 °C or 4 °C and periodically checked for viability. The freeze dried cells on carrier supports were directly used to prepare fermented milks to establish the activity of these cultures. Scanning electron microscopy was employed to visualize the support matrix with the attached lactic acid bacteria. The freeze drying process resulted in a 3.0 log cycle reduction in the colony forming units as compared to the original cell suspension in the case of all the lactic acid bacteria. The growth of lactic acid bacteria in the presence of bacterial cellulose (nata) offers a convenient and easy method to preserve bacteria for short durations and use it as a support to carry out other fermentation processes.     

Influence of adjunct use and cheese microenvironment on nonstarter bacteria in reduced-fat cheddar-type cheese

This study investigated population dynamics of starter, adjunct, and nonstarter lactic acid bacteria (NSLAB) in reduced-fat Cheddar and Colby cheese made with or without a Lactobacillus casei adjunct. Duplicate vats of cheese were manufactured and ripened at 7 degrees C. Bacterial populations were monitored periodically by plate counts and by DNA fingerprinting of cheese isolates with the random amplified polymorphic DNA technique. Isolates that displayed a unique DNA fingerprint were identified to the species level by partial nucleotide sequence analysis of the 16S rRNA gene. Nonstarter biota in both cheese types changed over time, but populations in the Colby cheese showed a greater degree of species heterogeneity. The addition of the L. casei adjunct to cheese milk at 10(4) cfu/ml did not completely suppress "wild" NSLAB populations, but it did appear to reduce nonstarter species and strain diversity in Colby and young Cheddar cheese. Nonetheless, nonstarter populations in all 6-mo-old cheeses were dominated by wild L. casei. Interestingly, the dominant strains of L. casei in each 6-mo-old cheese appeared to be affected more by adjunct treatment and not cheese variety.     

Antimicrobial activity of lactic acid bacteria against Listeria monocytogenes on frankfurters formulated with and without lactate/diacetate

Contamination by Listeria monocytogenes has been a constant public health threat for the ready-to-eat (RTE) meat industry due to the potential for high mortalities from listeriosis. Lactic acid bacteria (LAB) have shown protective action against various pathogenic bacteria. The aim of this study was to evaluate the antilisterial activity of a combination of three LAB strains (Lactiguard®) on L. monocytogenes. The combination of the LAB was inhibitory to L. monocytogenes inoculated onto frankfurters not containing lactate/diacetate after 8 weeks of refrigerated storage (0.6 log reduction compared to L. monocytogenes only control), and when a cell free extract (CFS) of the LAB was added with LAB even more inhibition was obtained (1.2 log reduction compared with L. monocytogenes only). In frankfurters containing lactate/diacetate the LAB and the LAB plus CFS were more effective in reducing growth of L. monocytogenes after 8 weeks of refrigerated storage (2 and 3.3 log reductions respectively).     

Identification of subdominant sourdough lactic acid bacteria and their evolution during laboratory-scale fermentations

Presumptive lactic acid bacterial cocci were found in six sourdoughs (out of 20) from the Abruzzo region (central Italy) and subjected to phenotypic and genotypic characterization. A total of 21 isolates, recognized as seven strains by randomly amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR) typing, were identified by a polyphasic approach, consisting of 16S rRNA gene sequencing, multiplex PCR assays and physiological features, as Enterococcus faecium and Pediococcus pentosaceus. Four strains belonging to those species and previously isolated from wheat kernels were inoculated in sterile flour to verify their capacity to grow in sourdough environment. Doughs with several dual bacterial combinations, including Lactobacillus sanfranciscensis, were propagated for 11 days and pH measurements and bacterial counts were carried out.     

Heat shock effects on the viability of Cronobacter sakazakii during the dehydration,fermentation, and storage of lactic cultured milk products

In the present study, the viability of heat-shocked and non-shocked Cronobacter sakazakii, a foodborne pathogen, after drying and during the fermentation as well as storage of lactic cultured milk was evaluated. It was found that heat shock increased the viability of C. sakazakii. The pure culture of C. sakazakii, regardless of heat shock, grew rapidly in skim milk with a viable population of ca. 8.59–8.70 log cfu/ml after ca. 48 h of cultivation. Thereafter, the viable population of C. sakazakii remained stable. While in the mix culture with Streptococcus thermophilus or Lactobacillus bulgaricus, a marked reduction in the viable population of C. sakazakii was noted after 24 h of cultivation in skim milk. Nevertheless, at the end of fermentation, the heat-shocked C. sakazakii had a viable population of 5.93–6.01 log cfu/ml, which is significantly higher (P < 0.05) than that of non-shocked cells of 4.96–4.99 log cfu/ml. While the presence of C. sakazakii did not affect the growth of lactic acid bacteria in skim milk. Additionally, heat shock was found to enhance the survival of C. sakazakii after freeze-drying or spray-drying and during the storage of the lactic fermented milk products (pH 4.3) at 5 °C for 48 h.