Assessment of the immunomodulatory properties of the probiotic strain Lactobacillus paracasei K5 in vitro and in vivo

Lactobacillus paracasei K5 is a lactic acid bacteria (LAB) strain that has been isolated from dairy products. Previous studies have established its probiotic potential in a series of in vitro tests, including molecular characterization, safety profiling, and tolerability of the gastrointestinal tract conditions. To characterize its beneficial actions on the host, we have shown previously that L. paracasei K5 adheres to Caco-2 cells and exerts anti-proliferative effects through the induction of apoptosis. In the present study, we focused on the immunomodulatory potential of this strain. We employed the dorsal-air-pouch mouse model of inflammation and recorded an eight-fold increase in the recruitment of immune cells in mice treated with the probiotic strain, compared to the control group. Analysis of the exudates revealed significant changes in the expression of pro-inflammatory mediators on site. Treatment of Caco-2 cells with L. paracasei K5 induced significant upregulation of cytokines interleukin-1α (IL-1α), ΙL-1β, IL-6, tumor necrosis factor-alpha (TNF-α), the chemokine C-X-C motif ligand 2 (CXCL2), and the inflammation markers soluble intercellular adhesion molecule (sICAM) and metallopeptidase inhibitor-1 (TIMP-1). Transient induction of the Toll-like receptors (TLRs) 2, 4, 6, and 9 expression levels was recorded by real-time PCR analysis. These results highlight the immunomodulatory potential of this strain and further support its probiotic character

Kefir as a Functional Beverage Gaining Momentum towards Its Health Promoting Attributes

The consumption of fermented foods posing health-promoting attributes is a rising global trend. In this manner, fermented dairy products represent a significant subcategory of functional foods with established positive health benefits. Likewise, kefir—a fermented milk product manufactured from kefir grains—has been reported by many studies to be a probiotic drink with great potential in health promotion. Existing research data link regular kefir consumption with a wide range of health-promoting attributes, and more recent findings support the link between kefir’s probiotic strains and its bio-functional metabolites in the enhancement of the immune system, providing significant antiviral effects. Although it has been consumed for thousands of years, kefir has recently gained popularity in relation to novel biotechnological applications, with different fermentation substrates being tested as non-dairy functional beverages. The present review focuses on the microbiological composition of kefir and highlights novel applications associated with its fermentation capacity. Future prospects relating to kefir’s capacity for disease prevention are also addressed and discussed

Upgrading of Mixed Food Industry Side-Streams by Solid-State Fermentation with P. ostreatus

In the frame of efforts to exploit agroindustrial side-streams and wastes (AISS) for added-value products that are based on single cell protein (SCP), mixed substrates consisting of brewer’s spent grains (BSG), malt spent rootlets (MSR), cheese whey, molasses, orange, and potato pulps, were used for growth of the edible mushroom Pleurotus ostreatus. The substrates were mixed in various combinations, and were used for P. ostreatus growth at various conditions. The substrate, for which the highest sugar consumption, protein increase, and mycelium yield were observed, consisted of 20 mL molasses (4° Baume density), 20 mL potato pulp, 5 mL whey, 5 mL orange pulp, 30 g BSG, and 5 g MSR (at 25 °C and substrate pH 4). The mycelium-enriched product was analyzed for protein, fat, minerals (Ca, Mg, Fe, Cu), and aroma volatile compounds, indicating the potential for use as nutritious supplement for food, feed, or microbiology uses. The product was also autolyzed, freeze-dried, powdered, and analyzed for total ribonucleic acid content, showing the potential for use as a commercial natural food flavor enhancer

Production of a Novel Functional Fruit Beverage Consisting of Cornelian Cherry Juice and Probiotic Bacteria

The present study describes the development of a novel functional beverage through the application of probiotic Lactobacillus plantarum ATCC (American Type Culture Collection) 14917 in Cornelian cherry juice fermentation. The probiotic was employed in free and immobilized in a delignified wheat bran carrier (DWB) form. Cornelian cherry juice was fermented for 24 h and then it was stored at 4 °C for 4 weeks. Several parameters were evaluated such as residual sugar, organic acid and alcohol levels, total phenolics content, and cell viability as well as consumers acceptance. Regarding sugar and organic acids analyses, it was proved that the probiotic free or immobilized biocatalyst was effective. The concentration of ethanol was maintained at low levels (0.3–0.9% v/v). The total phenolic content of fermented Cornelian cherry juice with immobilized cells was recorded in higher levels (214–264 mg GAE/100 mL) for all the cold storage time compared to fermented juice with free cells (165–199 mg GAE/100 mL) and non-fermented juice (135–169 mg GAE/100 mL). Immobilized cells retained their viability in higher levels (9.95 log cfu/mL at the 4th week) compared to free cells (7.36 log cfu/mL at the 4th week). No significant sensory differences were observed among the fermented and the non-fermented samples

Advancements in the Use of Fermented Fruit Juices by Lactic Acid Bacteria as Functional Foods: Prospects and Challenges of <i>Lactiplantibacillus</i> (<i>Lpb.</i>) <i>plantarum</i> subsp. <i>plantarum</i> Application

Lactic acid fermentation of fresh fruit juices is a low-cost and sustainable process, that aims to preserve and even enhance the organoleptic and nutritional features of the raw matrices and extend their shelf life. Selected Lactic Acid Bacteria (LAB) were evaluated in the fermentation of various fruit juices, leading in some cases to fruit beverages, with enhanced nutritional and sensorial characteristics. Among LAB, Lactiplantibacillus (Lpb.) plantarum subsp. plantarum strains are quite interesting, regarding their application in the fermentation of a broad range of plant-derived substrates, such as vegetables and fruit juices, since they have genome plasticity and high versatility and flexibility. L. plantarum exhibits a remarkable portfolio of enzymes that make it very important and multi-functional in fruit juice fermentations. Therefore, L. plantarum has the potential for the production of various bioactive compounds, which enhance the nutritional value and the shelf life of the final product. In addition, L. plantarum can positively modify the flavor of fruit juices, leading to higher content of desirable volatile compounds. All these features are sought in the frame of this review, aiming at the potential and challenges of L. plantarum applications in the fermentation of fruit juices

Innovations in Sourdough Bread Making

The application of sourdough is considered to be a key tool for the production of high-quality bread. Several advantages have been presented through the application of sourdough in bread making, such as increased shelf life, improved aromatic profiles and sensory characteristics, increased nutritional value, and health benefits. Technological benefits have also been recorded, such as the successful application of sourdough in gluten-free breads. Likewise, an upsurge of interest in sourdough applications in bread making as well as in other foodstuffs (pasta) has been witnessed in recent years. Many factors are considered important for sourdough preparations; however, the proper selection of the starter cultures is considered the most central. This Special Issue of Fermentation aims to disseminate recent innovative research regarding sourdough bread making, as well as authoritative reviews that compile information from previously published material

The Rendering of Traditional Fermented Foods in Human Diet: Distribution of Health Benefits and Nutritional Benefits

Most fermented foods are based on the cultural preferences of different geographical areas and the heterogeneity of traditions from where they are produced. For instance, many consumers in Asian countries prefer fermented seafood, while consumers in Europe prefer fermented cereal and dairy food products. Even though the food industry has developed various novel techniques in order to produce novel foods (genetic modification, nanotechnology and other processing techniques), traditional foods still represent a significant proportion of the food industry, which has recently appeared to develop further. In addition, the progress in various developed analytical techniques has revealed new knowledge that documents and corroborates certain benefits of traditional foods, mostly regarding their nutritional and health benefits. In this context, the main target of this Special Issue is to deliver new data on how traditional foods exhibit their health-promoting properties and ameliorate the nutritional value of fermented food systems. In addition, the involvement of wild starter culture in the production of traditional foods is a subject area that must be highlighted

Quality Characteristics of Novel Sourdough Breads Made with Functional Lacticaseibacillus paracasei SP5 and Prebiotic Food Matrices

Lacticaseibacillus paracasei SP5, isolated from kefir, was assessed as a starter culture for sourdough bread making in freeze-dried form, both free (BSP5 bread) and immobilised on wheat bran (BIWB) and on a traditional flour/sour milk food, &lsquo;trahanas&rsquo; (BITR). Physicochemical characteristics, shelf-life, volatilome, phytic acid, and sensory properties of the breads were evaluated. The BITR breads had higher acidity (9.05 &plusmn; 0.14 mL of 0.1 M NaOH/10 g) and organic acid content (g/Kg; 2.90 &plusmn; 0.05 lactic, 1.04 &plusmn; 0.02 acetic), which justifies the better resistance against mould and rope spoilage (&gt;10 days). The highest number of volatiles (35) and at higher concentration (11.14 &mu;g/g) were also found in BITR, which is in line with the sensory (consumer) evaluation regarding flavour. Finally, higher reduction of phytate (an antinutrient) was observed in all L. paracasei SP5 sourdoughs (83.3&ndash;90.7%) compared to the control samples (71.4%). The results support the use of the new strain for good quality sourdough bread

Solid residues of agisultural products and agricultural industies as cell immobilization substrates for use of baker's

Research on the exploitation of agricultural and agro-industrial waste has been intensified over the last years. The prevalent tendency is the transformation of these wastes as fermentation substrates for growth and production of microorganisms, as well as for the production of new foods of high nutritional value and low cost. The use of immobilization method becomes more attractive, because it combines both of them. A large number of reports exists dealing with the exploitation of agro-industrial wastes as substrates for cell immobilization for the production of alcohol, beer and wine. Reports on the use of immobilization method in breadmaking have not been published so far. Likewise the present thesis has focused on the exploitation of solid orange residues, produced as wastes of orange juice factories and of spent grains of breweries in breadmaking. A model immobilized biocatalyst with high nutritional value was prepared, by immobilizing yeast cells in a Greek traditional cereal food called trahanas. This biocatalyst is considered as a new baker’s yeast and presents several advantages. The most important of which is the presence of lactic bacteria and yeasts, the high similarity with flour, which is the basic raw material of bread and its high nutritional value, due to its composition (starch, gluten and milk). Furthermore apple and orange fruits, which are rejected in the landfills, were also tested as fermentation substrates for the production of cellular biomass. In addition experimental observations led to investigation of the promoter effect of orange peel pieces in continuous and batch aerobic fermentations of molasses. At the first part of the experiments a mixture of wheat flour and sour milk was treated according to the method of the traditional Greek fermented food trahanas, and was used as model cereal-based support (starch-gluten-milk matrix) for co-immobilization of lactic acid bacteria and yeast for potential use in food production. Cell immobilization was verified by electron microscopy and by the efficiency of the immobilized biocatalyst for alcoholic and lactic acid fermentation at various temperatures. Fermentation times were low and ethanol production was high and stable, showing good operational stability of the biocatalyst and suitability for commercial applications. Finally, large amounts of lactic acid and volatile by-products were produced at all the studied temperatures, revealing potential application of the proposed biocatalyst in fermented food production or use as food additive, in order to improve nutritional value, flavour formation and preservation time. Additionally, another two biocatalysts were also prepared by immobilizing a commercial Saccharomyces cerevisiae strain (baker’s yeast) on orange peel pieces and brewer’s spent grains respectively, for use in alcoholic fermentation and potential use in fermented food applications. Cell immobilization was verified by electron microscopy and by the efficiency of the immobilized biocatalysts for alcoholic fermentation. In the case of orange peel pieces various carbohydrate substrates were used (molasses, raisin extracts) besides glucose, at various temperatures. Fermentation times in all cases were low and ethanol productivities were high, showing good operational stability of the biocatalysts and suitability for commercial applications. Respectable amounts of volatile by-products were produced at all the studied temperatures, revealing potential application of the proposed biocatalysts in fermented food applications. The second part of the experiments dealt with production of cellular biomass. At first, diluted orange and apple pulps were used for biomass production. The microorganisms that were used were baker’s yeast cells and kefir culture. The results were compared with those, resulting from aerobic fermentations of molasses, which is the classic substrate for the production of baker’s yeast in industry. The results were of great significance. Higher biomass yields, biomass concentrations and biomass productivities were achieved in all the cases of using fruits compared to molasses. Orange pulp gave higher biomass productivities compared to the apple pulp. On the other hand, apple pulp gave higher biomass yields. Using orange pulp with addition of baker’s yeast cells, the biomass productivity was almost double in comparison to molasses. In the case of apple pulp with baker’s yeast cells, the biomass yield was double than that using of molasses. In all the above experiments the use of baker’s yeast cells gave better results than those of the kefir culture. Furthermore improvements of growth rate and productivity in biomass production using orange peel as promoter were observed in batch aerobic fermentation. Daily biomass productivity and biomass yield respectively were found higher in batch aerobic fermentation in the presence of orange peel as promoter. A novel bioreactor for continuous aerobic fermentation of molasses was used and the suitability for baker’s yeast production using orange peel as promoter was proved. The continuous bioreactor was operated for 12 days, stored for 20 days at 10oC and operated again for another 13 days without any diminution of biomass productivity. The third part of the experiments focused in breadmaking by using the aforementioned biocatalysts. For comparison purposes, bread was also made by free cells of baker’s yeast. In addition, kefir culture was used immobilized in the solid orange residues and spent brewery grains. The leavening activity of the immobilized biocatalysts and kefir grains in lean dough and their efficiency to produce bread of good quality, in terms of loaf volume, flavour, texture and shelf life, was evaluated. The best rising was obtained in the case of kefir grains and of immobilized yeast cells on trahana. Two methods were used for breadmaking, the direct method and the traditional sourdough method. The results proved, that the breads prepared with the direct method from immobilized cells, had almost the same qualitative and quantitative characteristics with those of commercial bread, with the exception of immobilized yeast cells and kefir in spent grains. The above results were confirmed by sensory evaluations and analyses of volatile compounds with SPME-GC-MS. Immobilized trahanas and kefir culture gave the more satisfactory results. The breads that were prepared with the sourdough method had superior quality, as it appeared also from sensory evaluations, that were carried out. They had better texture, flavour and gave more volatile compounds compared to all breads that were prepared with the direct method. The best sourdoughs were those prepared by immobilized cells in trahana and by kefir culture. The breads that were made were better in quality and nutritional value and presented higher preservation times in terms of staling and molding. In conclusion, the immobilized cells, as well as kefir culture proved to be successful biocatalysts in breadmaking. Likewise, the development and exploitation of substrates, such as the solid orange residues and spent brewery grains for the production of novel baker’s yeast, could solve the enormous ecological problems, caused by their rejection in the environment.Οι έρευνες για την εκμετάλλευση γεωργικών και αγροτοβιομηχανικών απορριμμάτων έχουν ενταθεί τα τελευταία χρόνια. Η τάση, που επικρατεί είναι η χρήση αυτών των απορριμμάτων ως υποστρωμάτων ζύμωσης για ανάπτυξη και παραγωγή μικροοργανισμών, καθώς και για παραγωγή νέων τροφίμων υψηλής προστιθέμενης αξίας και χαμηλού κόστους. Η χρήση της μεθόδου της ακινητοποίησης είναι πολύ ελκυστική, επειδή συνδυάζει και τα δύο. Πολλές αναφορές υπάρχουν για την εκμετάλλευση απορριμμάτων σαν υποστρώματα ακινητοποίησης για την παραγωγή αλκοόλης, μπύρας και κρασιού. Aναφορές για χρήση της μεθόδου ακινητοποίησης στην παρασκευή άρτου δεν υφίστανται στην βιβλιογραφία. Για το λόγο αυτό, η παρούσα διατριβή επικεντρώθηκε στην εκμετάλλευση των στερεών του πορτοκαλιού, που προέρχονται από τα απορρίμματα των εργοστασίων χυμοποίησης και των στερεών απορριμμάτων ζυθοποιίας στην παρασκευή άρτου. Συγχρόνως παρασκευάστηκε πρωτότυπος ακινητοποιημένος βιοκαταλύτης υψηλής διατροφικής αξίας, με ακινητοποίηση κυττάρων σε τραχανά, για.να χρησιμοποιηθεί ως νέα ζύμη αρτοποιίας. Ο βιοκαταλύτης αυτός παρουσιάζει πολλά πλεονεκτήματα. Τα σημαντικότερα εκ των οποίων, είναι η παρουσία γαλακτικών βακτηρίων και ζυμών, η μεγάλη διατροφική συγγένεια με το αλεύρι, που είναι η βασική πρώτη ύλη στην παρασκευή άρτου, καθώς και η υψηλή διατροφική του αξία, επειδή αποτελείται από άμυλο, γλουτένη και γάλα. Παράλληλα, εξετάστηκαν τα μήλα και τα πορτοκάλια, τα οποία απορρίπτονται στις χωματερές, σαν νέα υποστρώματα στην αερόβια παραγωγή κυτταρικής βιομάζας. Τέλος μελετήθηκε η επίδραση των στερεών πορτοκαλιού στις κινητικές παραμέτρους των αερόβιων ζυμώσεων μελάσας για παραγωγής ζύμης αρτοποιίας σε συνεχές και ασυνεχές σύστημα. Σε πρώτη φάση έγινε η παρασκευή νέου πρωτότυπου βιοκαταλύτη από ξυνισμένο γάλα και αλεύρι, σύμφωνα με την μέθοδο παρασκευής του παραδοσιακού τραχανά. Ο παραπάνω βιοκαταλύτης ήταν ακινητοποιημένος με ζύμη αρτοποιίας που προστέθηκε κατά την διαδικασία της ακινητοποίησης, αλλά και με γαλακτικά βακτήρια, που φέρει ο ίδιος προερχόμενα από το ξυνισμένο γάλα που παρασκευάστηκε. Η ακινητοποίηση αποδείχθηκε μέσω φωτογραφιών ηλεκτρονικού μικροσκοπίου και μέσω επαναλαμβανόμενων παρτίδων αλκοολικής και γαλακτικής ζύμωσης. Οι χρόνοι ζύμωσης ήταν μικροί και η παραγωγικότητα αλκοόλης σχετικά υψηλή και σταθερή σε όλες τις θερμοκρασίες ζύμωσης. Ο νέος βιοκαταλύτης παρουσίασε ικανοποιητική λειτουργική σταθερότητα και παρήγαγε σημαντικές ποσότητες γαλακτικού οξέος και πτητικών παραπροϊόντων σε όλες τις παρτίδες ζύμωσης. Τα παραπάνω απέδειξαν την καταλληλότητά του στην παραγωγή ζυμώσιμων τροφίμων, καθώς και στην πιθανή χρήση του ως πρόσθετο για την αύξηση της διατροφικής αξίας, του αρώματος και του χρόνου συντήρησης των τροφίμων. Επιπρόσθετα δύο ακόμα βιοκαταλύτες παρασκευάστηκαν με ακινητοποίηση κυττάρων ζύμης αρτοποιίας σε στερεά του πορτοκαλιού και σε στερεά απορρίμματα ζυθοποιίας αντίστοιχα και εξετάστηκε η απόδοσή τους στην αλκοολική ζύμωση. Η ακινητοποίηση των κυττάρων αποδείχθηκε μέσω φωτογραφιών ηλεκτρονικού μικροσκοπίου και από επαναλαμβανόμενες παρτίδες ζύμωσης συνθετικού θρεπτικού μέσου γλυκόζης. Στην περίπτωση χρήσης των ακινητοποιημένων κυττάρων σε στερεά του πορτοκαλιού μελετήθηκε επιπλέον η ζύμωση μελάσας και εκχυλίσματος σταφίδας. Όλα τα συστήματα των ακινητοποιημένων βιοκαταλυτών παρουσίασαν ικανοποιητικά αποτελέσματα στις ζυμώσεις, με υψηλές τιμές σε μετατροπή και παραγωγικότητα σε αιθανόλη, καθώς και αποδεκτά ποσοστά πτητικών παραπροϊόντων. Αναφορικά με τις κινητικές παραμέτρους των ζυμώσεων, καλύτερος φορέας ακινητοποίησης αποδείχθηκαν τα στερεά του πορτοκαλιού. Η δεύτερη φάση της διατριβής εστιάσθηκε στην παραγωγή κυτταρικής βιομάζας. Αρχικά εξετάστηκαν αραιωμένοι πολτοί πορτοκαλιού και μήλου για παραγωγή κυτταρικής βιομάζας. Οι μικροοργανισμοί, που χρησιμοποιήθηκαν ήταν κύτταρα ζύμης αρτοποιίας και kefir. Τα αποτελέσματα συγκρίθηκαν με αυτά, που προέκυψαν από αερόβιες ζυμώσεις μελάσας, που είναι το κλασσικό υπόστρωμα για την βιομηχανική παραγωγή ζύμης αρτοποιίας. Τα αποτελέσματα κρίθηκαν ικανοποιητικά. Συγκεκριμένα, μεγαλύτερες συγκεντρώσεις, αποδόσεις και παραγωγικότητες βιομάζας επιτεύχθηκαν στην περίπτωση χρήσης των φρούτων σε σύγκριση με την μελάσα. Ο πολτός πορτοκαλιού έδωσε υψηλότερες παραγωγικότητες βιομάζας από το μήλο. Από την άλλη μεριά ο πολτός μήλου έδωσε το υψηλότερες αποδόσεις βιομάζας. Συγκεκριμένα, στην περίπτωση χρήσης του πολτού πορτοκαλιού με προσθήκη ζύμης αρτοποιίας, η παραγωγικότητα βιομάζας ήταν σχεδόν διπλάσια από αυτήν, που έδωσε η χρήση της μελάσας. Όταν χρησιμοποιήθηκε πολτός μήλου με ζύμη αρτοποιίας η απόδοση βιομάζας ήταν περίπου διπλάσια συγκριτικά με τη μελάσα. Σε όλες τις περιπτώσεις, η χρήση ζύμης αρτοποιίας έδωσε καλύτερα αποτελέσματα από το kefir. Παράλληλα, από πειραματικές παρατηρήσεις προέκυψε, ότι σε αερόβιες ζυμώσεις μελάσας παρουσία στερεών του πορτοκαλιού, παρατηρήθηκε αύξηση της τελικής συγκέντρωσης, της παραγωγικότητας και της απόδοσης βιομάζας, καθώς και του εκατοστιαίου ποσοστού μετατροπής. Επιπλέον τα στερεά του πορτοκαλιού δοκιμάστηκαν ως προωθητές σε συνεχή ζύμωση μελάσας για παραγωγή ζύμης αρτοποιίας. Ο βιοαντιδραστήρας λειτούργησε για 12 ημέρες, αποθηκεύτηκε στους 100C και επαναλειτούργησε για άλλες 13 ημέρες, χωρίς μείωση της παραγωγικότητας της βιομάζας. Το τρίτο μέρος της διατριβής εστιάζεται στην παρασκευή άρτων από τους προαναφερθέντες βιοκαταλύτες, αλλά και από ελεύθερα κύτταρα ζύμης αρτοποιίας. Επιπρόσθετα χρησιμοποιήθηκε kefir, καθώς και ακινητοποιημένα κύτταρα kefir σε στερεά του πορτοκαλιού και σε στερεά απορρίμματα ζυθοποιίας. Αξιολογήθηκε η διογκωτική ικανότητα και η αποδοτικότητα των βιοκαταλυτών στην παραγωγή άρτου καλής ποιότητας, αναφορικά με τον όγκο, το άρωμα, την υφή και τον χρόνο συντήρησης. Οι άρτοι παρασκευάστηκαν με την άμεση μέθοδο και τη μέθοδο του προζυμιού. Τα αποτελέσματα έδειξαν, ότι οι άρτοι, που παρασκευάστηκαν με την άμεση μέθοδο από ακινητοποιημένα κύτταρα είχαν περίπου τα ίδια ποιοτικά χαρακτηριστικά με αυτά του εμπορικού άρτου, με εξαίρεση την περίπτωση των ακινητοποιημένων κύτταρων ζύμης αρτοποιίας και kefir σε στερεά απορρίμματα ζυθοποιίας. Τα αποτελέσματα αυτά επιβεβαιώθηκαν από οργανοληπτικούς ελέγχους και με ανάλυση των πτητικών ενώσεων των άρτων με SPME-GC-MS. Ο ακινητοποιημένος τραχανάς και το ελεύθερο kefir έδωσαν τα πιο ικανοποιητικά αποτελέσματα. Οι άρτοι, που παρασκευάστηκαν με την μέθοδο του προζυμιού ήταν ανώτερης ποιότητας, όπως φάνηκε και από τους οργανοληπτικούς ελέγχους, που διεξάχθηκαν, είχαν καλύτερη υφή, γεύση και έδωσαν περισσότερες πτητικές ενώσεις από όλους τους άρτους, που παρασκευάστηκαν με την άμεση μέθοδο. Τα προζύμια, που είχαν παρασκευαστεί από ακινητοποιημένα κύτταρα σε τραχανά και από kefir έδωσαν τους ποιοτικότερους άρτους με τους μεγαλύτερους χρόνους συντήρησης. Συμπερασματικά, τα ακινητοποιημένα κύτταρα ζύμης αρτοποιίας σε τραχανά και τα ακινητοποιημένα κύτταρα ζύμης αρτοποιίας και kefir σε στερεά πορτοκαλιού αντίστοιχα, καθώς και το kefir εξετάστηκαν επιτυχημένα στην παραγωγή άρτου. Παράλληλα αξιοποιώντας υποστρώματα, όπως τα στερεά πορτοκαλιού και τα στερεά απορρίμματα ζυθοποιίας για παρασκευή νέων ζυμών αρτοποιίας, δίνεται συγχρόνως λύση στα τεράστια οικολογικά προβλήματα, που προκαλεί η απόρριψή τους στο περιβάλλον

Valorization of Lactic Acid Fermentation of Pomegranate Juice by an Acid Tolerant and Potentially Probiotic LAB Isolated from Kefir Grains

The present study describes the application of an acid tolerant and potentially probiotic L. paracasei SP3 strain, recently isolated from kefir grains, in the production of a novel functional beverage based on the fermentation of pomegranate juice. The fermentation ability of the novel strain was assessed during pomegranate juice fermentations at 30 &deg;C for 24 h and storage at 4 &deg;C for 4 weeks. Various parameters were assessed such as residual sugar, organic acid and alcohol levels, total phenolics content, antioxidant activity, astringency, cell viability, and consumer acceptance. Residual sugar was decreased by approximately 25%, while respectable amounts of lactic acid were determined (4.8 g/L) on the 28th day of storage, proving that the novel strain was effective at lactic acid fermentation. The concentration of ethanol was maintained at low levels (0.3&ndash;0.4 % v/v) and low levels of acetic acid were detected (0.6 g/L). The viability of L. paracasei SP3 cells retained high levels (&gt;7 log cfu/mL), even by the 4th week. The total phenolic content (123.7&ndash;201.1 mg GAE/100 mL) and antioxidant activity (124.5&ndash;148.5 mgTE/100 mL) of fermented pomegranate juice were recorded at higher levels for all of the studied time periods compared to the non-fermented juice. The employment of the novel strain led to a significant reduction in the levels of hydrolysable tannins (42%) in the juice, reducing its astringency. The latter was further proven through sensorial tests, which reflected the amelioration of the sensorial features of the final product. It should be underlined that fruit juices as well as pomegranate juice comprised a very harsh food matrix for microorganisms to survive and ferment. Likewise, the L. paracasei SP3 strain showed a significant potential, because it was applied as a free culture, without the application of microencapsulation methods that are usually employed in these fermentations, leading to a product with possible functional properties and a high nutritive value