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This research effort aimed at isolating and phenotypically characterizing lactic acid bacteria (LAB) isolates from a spontaneous rye sourdough manufactured following traditional protocols, as well as at evaluating their antimicrobial and antifungal properties as key features for future industrial applications. Thirteen LAB strains of potential industrial interest were isolated and identified to species-level via PCR. Most of the sourdough isolates showed versatile carbohydrate metabolisms. The Leuconostoc mesenteroides No. 242 and Lactobacillus brevis No. 173 demonstrated to be gas producers; thus, revealing their heterofermenter or facultative homofermenter features. Viable counts higher than 7.0 log10 (CFU/mL) were observed for Lactobacillus paracasei No. 244, Lactobacillus casei No. 210, L. brevis No. 173, Lactobacillus farraginis No. 206, Pediococcus pentosaceus No. 183, Lactobacillus uvarum No. 245 and Lactobacillus plantarum No. 135 strains, after exposure at pH 2.5 for 2 h. Moreover, L. plantarum No. 122, L. casei No. 210, Lactobacillus curvatus No. 51, L. paracasei No. 244, and L. coryniformins No. 71 showed growth inhibition properties against all the tested fifteen pathogenic strains. Finally, all LAB isolates showed antifungal activities against Aspergillus nidulans, Penicillium funiculosum, and Fusarium poae. These results unveiled the exceptionality of spontaneous sourdough as a source of LAB with effective potential to be considered in the design of novel commercial microbial single/mixed starter cultures, intended for application in a wide range of agri-food industries, where the antimicrobial and antifungal properties are often sought and necessary. In addition, metabolites therefrom may also be considered as important functional and bioactive compounds with high potential to be employed in food and feed, as well as cosmetic and pharmaceutical applications.

BACKGROUND By‐products from berries/fruits (B/F) and the dairy industry (DI) are an important environmental issue in many countries. In the present study, the concept of an improvement of the antimicrobial activity of lactic acid bacteria (LAB) in combination with B/F (raspberries, blackcurrants, apples, rowanberries) and DI by‐products was analysed. Antimicrobial activities of the B/F by‐products and LAB (13 LAB strains were estimated against 15 pathogenic strains) were evaluated, with whey substrate being used for the selected and the highest antimicrobial activities showing LAB cultivation. RESULTS The broadest spectrum of pathogenic bacteria inhibition was shown by lyophilised blackcurrant and apple by‐products, which inhibited 13 and 12 pathogenic strains of the 15 strains analysed, respectively. The strongest inhibition of the tested pathogens were shown by the Lactobacillus uvarum LUHS245 and Lactobacillus casei LUHS210 and, for the abovementioned LAB biomass preparation, whey enriched with 2.5 g 100 g−1 glucose, 2.0 g 100 g−1 yeast extract and 0.5 g 100 g−1 saccharose is a suitable and sustainable substrate. The B/F by‐product's antimicrobial activity can be enhanced in combination with the LUHS245 and LUHS210 strains. CONCLUSION LAB, B/F and DI by‐products can be used for preparation of antimicrobial products because the combination of compounds from different origins showed higher antimicrobial properties. © 2019 Society of Chemical Industry

SSF improved lupin and soya bean protein digestibility. BLIS-producing LAB in lupin and soya bean medium produced a mixture of D- and L-lactic acid with a major excess of the latter isomer. Most toxic histamine and tyramine in fermented lupin and soya bean were found at levels lower those causing adverse health effects. Selection of biogenic amines non-producing bacteria is essential in the food industry to avoid the risk of amine formation.

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Summary The aim of this study was to develop antimicrobial properties of gummy candies based on bovine colostrum (BC), essential oils (EOs), lactic acid bacteria (LAB) strains and their combinations. In addition, the heteropolysaccharide (agar), as a multifunctional polymer, was used for the antimicrobial candies preparation. The antimicrobial activities of BC, EOs (C. reticulata L., Eugenia caryophyllata, C. paradisi L., Thymus vulgaris), LAB strains (Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244) and their combinations against pathogenic bacteria (Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Salmonella enterica, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans) were investigated. The highest antimicrobial activities were demonstrated by Thymus vulgaris and Eugenia caryophyllata EOs and their emulsions (12%), and the best formulation of components for antimicrobial gummy candies production would incorporate the BC fermented with L. paracasei LUHS244 in combination with Thymus vulgaris or Eugenia caryophyllata EOs, which inhibited growth of all the tested pathogenic microorganisms (except Pseudomonas aeruginosa). Gummy candies formula consisting of the fermented BC (up to 3%) and thyme EO (up to 0.2%) with mandarin or grapefruit EOs (up to 0.2%) for taste‐masking, allowed obtaining good texture and high overall acceptability products containing desirable antimicrobials, thus antimicrobial gummy candies could be consumer preferred form of nutraceuticals.

The present research study aims to prepare prototypes of beverages from milk permeate (MP) using fermentation with 10 different strains of lactic acid bacteria (LAB) showing antimicrobial properties (L. uvarum LUHS245, L. casei LUHS210, L. curvatus LUHS51, L. plantarum LUHS135, P. acidilactici LUHS29, L. plantarum LUHS122, L. coryniformins LUHS71, L. paracasei LUHS244, P. pentosaceus LUHS183, L. faraginis LUHS206) and MP with (AppMP) or without (MP) the addition of 8% (w/w) apple by-products (App). Two groups of prototypes of beverages were prepared: fermented MP and fermented MP with App (AppMP). Acidity parameters, LAB viable counts, lactose and galactooligosaccharides (GOSs) content, antimicrobial properties against 15 pathogenic and opportunistic bacterial strains, overall acceptability and emotions induced of the final fermented beverages for consumers were evaluated. Results showed that all LAB grew well in MP and LAB strain exhibited a significant (p ≤ 0.05) influence on galactobiose and galactotriose synthesis in the fermentable MP substrate. The highest total content of GOS (26.80 mg/100 mL) was found in MPLUHS29 fermented beverage. In addition, MPLUHS245, MPLUHS210 and AppMPLUHS71 fermented beverages showed high antimicrobial activity, inhibiting 13 out of 15 tested microbial pathogens. The overall acceptability of AppMP fermented beverages was 26.8% higher when compared with fermented beverages without App (MP), and the most intensive “happy” emotion was induced by MPLUHS71, MPLUHS24, MPLUHS183 and MPLUHS206 samples. Finally, very promising results were also attained by the bioconversion of MP with selected LAB and App addition into the prototypes of antimicrobial beverages enriched with GOS.

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