Danuta Kołożyn-Krajewska

The Effect of LAB as Probiotic Starter Culture and Green Tea Extract Addition on Dry Fermented Pork Loins Quality

The objective of this study was to evaluate the microbiological, physicochemical, and sensory quality of dry fermented pork loin produced with the addition of Lb. rhamnosus LOCK900 probiotic strain, 0.2% glucose, and 1.5% green tea extract. Three loins were prepared: control sample (P0: no additives), sample supplemented with glucose and probiotic strain (P1), and sample with glucose, green tea extract, and probiotic (P2). The samples were analyzed after 21 days of ripening and 180 days of storage. The results indicated that the highest count of LAB was observed both in the samples: with probiotic and with probiotic and green tea extract (7.00 log cfu/g after ripening; 6.00 log cfu/g after storage). The oxidation-reduction potential values were lower in the probiotic loin samples. Probiotic and green tea extract have not caused color changes of study loins during storage. The study demonstrated that an addition of probiotic and green tea extract to dry fermented loins is possible and had no impact on sensory quality after product storage.

Comparison of Antibacterial Activity of Lactobacillus plantarum Strains Isolated from Two Different Kinds of Regional Cheeses from Poland: Oscypek and Korycinski Cheese

Oscypek and korycinski are traditional Polish cheeses, exclusively produced in Tatra and in Podlasie region, respectively, produced from raw, unpasteurized milk. The 29 Lactobacillus plantarum strains were isolated on MRS agar from 12 cheese samples and used as a material for study. The main purpose of the work was to assess the antimicrobial properties and recognition of selected strains for the unique antagonistic activity and preservation role in food. It has been found that the highest antimicrobial activity was observed in the case of L. monocytogenes strains; however, the level of that activity was different depending on the Lb. plantarum strain. Strains from oscypek produced broad spectrum, and a few strains isolated from korycinski cheese produced a narrow spectrum of antimicrobial compounds, other than organic acids and hydrogen peroxide. Moreover, the antagonistic activity shown by Lb. plantarum strains is connected with the source from which a given strain was isolated. Strains isolated from oscypek cheese represented stronger activity against L. monocytogenes, whereas strains isolated from korycinski cheese were more active against E. coli. Strains Lb. plantarum Os13 and Kor14 could be considered as good candidates for protective cultures to extend durability of food products.

Amino acid profile and sensory characteristics of dry fermented pork loins produced with a mixture of probiotic starter cultures

BACKGROUND Proteolysis is a biochemical process in dry-aged meat products where proteins are metabolized and broken down to polypeptides, peptides, and free amino acids. In the literature it is reported that an appropriate choice of probiotic starter culture limits proteolytic changes in dry-fermented meat products. In this study the combined effect of a mixture of probiotic starter cultures on the free amino acid profile, total count of lactic acid bacteria, and the sensory quality of dry-aged pork loins after fermentation and after storing the vacuum-packed samples was evaluated. RESULTS LOCK900 and BB12 probiotic strains were the technologically best two-species mixture of starter cultures for the production of probiotic dry-aged pork loins. They allowed us to obtain products with high and stable bacterial count and acceptable sensory quality, both after 21 days of fermentation and after 2 months of cold storage. Changes in the free amino acid profile and increased intensity of the selected sensory attributes result from a significant share of probiotics in meat proteolysis occurring during fermentation and storage. CONCLUSION The results suggest the relevance of using probiotic bacteria as a two-species starter culture for the production of dry-aged products.

Safety assessment and antimicrobial properties of the lactic acid bacteria strains isolated from polish raw fermented meat products

ABSTRACT Twenty-one strains of the genus Lactobacillus and the genus Pediococcus, isolated from Polish raw fermented meat products, were examined for the potential probiotic properties: resistance to simulated gastric and intestine conditions, safety assessment, and antimicrobial properties. Strains were resistant to gastric enzymes and low pH (3–6 log CFU/mL decrease) and intestinal enzymes and bile salts (1–3 log CFU/mL decrease). Most strains were resistant to gentamycin, streptomycin, vancomycin, tetracycline, ciprofloxacin, and kanamycin. Three of them (Lb. brevis BAL1, BAL10, and KL5) produced β-glucuronidase, which excludes them from qualifying as safe. Seven strains had the ability to produce bacteriocins or bacteriocin-like substances. Overall, strains Lb. brevis SCH6, Pd. pentosaceus BAL6, and KL14 revealed selected superior characteristics (resistance to the gastrointestinal conditions, safety assessment, and antimicrobial properties) as compared to the other LAB strains investigated, which made them a viable bioprotective culture that can be inoculated in raw fermented meat products as starter cultures.

Potential of bacteriocins from lab to improve microbial quality of dry-cured and fermented meat products

Meat and meat products are an important component of the daily diet. Nevertheless, they are perishable goods and are prone to microbial contamination, which leads to an increased risk to the health of consumers as well as economic losses in the meat industry. Fermentation has been used for thousands of years to preserve meat. As a result of extensive biochemical reactions occurring in meat during fermentation and ripening, the condi- tions inhibiting the growth of pathogenic and spoilage bacteria are formed. These changes are catalyzed by endogenous meat enzymes and exogenous enzymes derived from natural contaminating bacteria or starter cultures applied. In dry-cured and fermented meat products they are represented mainly by lactic acid bacte- ria (LAB) that produce a wide range of compounds, such as bacteriocins, directed against other microorgan- isms. The use of bactericidal peptides does not affect the sensory quality of foodstuffs, so that they attract attention as alternative means of preserving the stability and safety of dry-cured products.

Evaluation of Technological Properties and Oxidative Stability of Organic Dry Fermented Probiotic Sausages During Long-Term Storage

Abstract The objective of this work was to study the oxidative stability of organic dry fermented probiotic sausages during long-term storage (6 months). Four test samples were prepared: sample A - control sausage, sample B - with 0.05% addition of sodium ascorbate, sample C - with addition of Lb. casei LOCK 0900 (2x106 CFU/g) probiotic strain, 0.6% of glucose, and 0.05% of sodium ascorbate, and sample D - with 0.05% of sodium ascorbate, probiotics, and 0.6% of lactose. The study covered evaluation of the ripening process (21 d) by evaluating loss in the sausage weight. The pH value, oxidation-reduction potential, TBARS values, acid number, peroxide number, browning index after ripening (0) and after 2nd, 4th, and 6th month of chilling storage were identified. The total colour difference of sausages subjected to 3 h exposure to fluorescent light, texture parameters, and count of lactic acid bacteria (LAB) were identified after ripening (0) and after 6 months of storage. It was observed that an addition of probiotic bacteria and glucose (sample C) contributed to a significant decrease in the pH value and water activity in the sausage directly after ripening and during the entire chilling storage period. In samples with probiotics the option with glucose had a lower (P≤0.05) pH value by ca. 0.5 unit as compared to the sample with lactose. Significantly higher (P≤0.05) values of TBARS were observed in samples with probiotics as compared to control samples. The greatest oxidation stability during the entire chilling storage period was found in the sample with sodium ascorbate. Among samples with probiotic strain, the sample with glucose had the lowest peroxide number value (0.58-3.56 meqO2/kg) and TBARS (1.10-2.08 mg MDA/kg) but also the greatest colour stability during exposure to light. The order of decline in oxidative stability was: sample B > sample C > sample D > sample A.

Trends and Possibilities of the Use of Probiotics in Food Production

Abstract This chapter introduces the possibility of using probiotics in food products as well as the trends in modern food technology that are directed towards producing healthy and safe foods. Functional foods are natural or processed foods that contain known biologically active compounds, which when administered in defined quantitative and qualitative amounts, provide a clinically proven health benefit. One example of a functional food is a probiotic. Probiotic products should contain probiotic microorganisms at levels of more than 106 CFU/g (CFU/mL) until the end of their shelf life. This is called the “minimum therapeutic” level. The ability of these products to improve health also depends on the raw material (matrix) used. Food matrices can affect the stability of probiotic microorganisms during passage through the gastrointestinal tract. The media should provide longevity and activity of these microorganisms. The choice of production technology for the manufacture of probiotic foods is dependent on the consistency of the raw material used (e.g., liquid or solid) and on the method of production (e.g., fermented or unfermented). Probiotics have traditionally been delivered to fermented dairy products. Another use of probiotics is in nondairy-fermented foods such as vegetables, fruits, and dry fermented meat products. An alternative embodiment of the modern food technology is to add the microencapsulated probiotic microorganisms to unfermented foods.

Safety of Probiotics

Abstract Probiotics are considered “generally recognized as safe,” and are widely used in the prevention and treatment of several diseases. However, four types of side effects may be connected with probiotics: systemic infections, risk of deleterious metabolic activities, risk of adjuvant side effects and immunomodulation, and risk of gene transfer. The most common adverse effects of probiotics include gastrointestinal disorders, such as diarrhea, nausea, flatulence, dyspepsia, and abdominal pain. Other side effects include respiratory infections, abscesses, allergic reactions, and severe medical conditions, such as sepsis, fungemia, and endocarditis. In recent years, many species of the genera Lactobacillus, Leuconostoc, Pediococcus, Enterococcus, and Bifidobacterium were isolated from various types of infective lesions. Common use of probiotics may increase the risk of side effects. An assessment of the risk connected with intake of edible probiotic products, based on the literary data of documented cases of infections caused by probiotics as well as epidemiological data, has been discussed in the chapter.

Food-Origin Lactic Acid Bacteria May Exhibit Probiotic Properties: Review

One of the most promising areas of development in the human nutritional field over the last two decades has been the use of probiotics and recognition of their role in human health and disease. Lactic acid-producing bacteria are the most commonly used probiotics in foods. It is well known that probiotics have a number of beneficial health effects in humans and animals. They play an important role in the protection of the host against harmful microorganisms and also strengthen the immune system. Some probiotics have also been found to improve feed digestibility and reduce metabolic disorders. They must be safe, acid and bile tolerant, and able to adhere and colonize the intestinal tract. The means by which probiotic bacteria elicit their health effects are not understood fully, but may include competitive exclusion of enteric pathogens, neutralization of dietary carcinogens, production of antimicrobial metabolites, and modulation of mucosal and systemic immune function. So far, lactic acid bacteria isolated only from the human gastrointestinal tract are recommended by the Food and Agriculture Organization (FAO) and World Health Organization (WHO) for use as probiotics by humans. However, more and more studies suggest that strains considered to be probiotics could be isolated from fermented products of animal origin, as well as from non-dairy fermented products. Traditional fermented products are a rich source of microorganisms, some of which may exhibit probiotic properties. They conform to the FAO/WHO recommendation, with one exception; they have not been isolated from human gastrointestinal tract. In light of extensive new scientific evidence, should the possibility of changing the current FAO/WHO requirements for the definition of probiotic bacteria be considered?

Acid contents and the effect of fermentation condition of Kombucha tea beverages on physicochemical, microbiological and sensory properties

ABSTRACT Kombucha is a healthy beverage which is a final result of tea fermentation by adding a starter culture of the acetic acid bacteria and yeasts. The effect of fermentation conditions on physicochemical, microbiological and sensory properties of Kombucha tea beverages was evaluated with emphasis placed on determining sugars and organic acids content, including pro-health glucuronic acid. Fermentation process was conducted for 10 days at 20°C, 25°C and 30°C. The optimal conditions for the fermentation of Kombucha tea beverages were a temperature of 25°C and a period of 10 days which allowed to retrieve a product with good physicochemical, microbiological and sensory quality. The content of glucuronic acid increased during fermentation at all temperatures reaching the highest, on the 10th day of fermentation at 25°C. It was observed that all beverages were a good overall quality, whereas Kombucha fermented at 25°C was assessed as the highest.