LONGLIFE

The LONGLIFE project involves Irish research partners (Teagasc and UCC) to develop innovative processes for transforming food substrates (milk, Teagasc and cereals, UCC) into fermentates, using novel strains of lactic acid bacteria (LAB) and yeasts to produce value-added fermented liquids and powders, and long-fermented sourdough bread with improved health benefits, improved organoleptic qualities and extended shelf-life. The objective is to deliver new knowledge on the fate and function of food constituents and determinants of bio-accessibility, bioavailability and efficacy of food ingredients to advance fermented functional food design. The aims included identification and characterisation food grade cultures with EPS, polyol antimicrobial and antifungal-producing properties. Bacterial strain screening was completed at both UCC and Teagasc.The LONGLIFE project involves Irish research partners (Teagasc and UCC) to develop innovative processes for transforming food substrates (milk, Teagasc and cereals, UCC) into fermentates, using novel strains of lactic acid bacteria (LAB) and yeasts to produce value-added fermented liquids and powders, and long-fermented sourdough bread with improved health benefits, improved organoleptic qualities and extended shelf-life. The objective is to deliver new knowledge on the fate and function of food constituents and determinants of bio-accessibility, bioavailability and efficacy of food ingredients to advance fermented functional food design. The aims included identification and characterisation food grade cultures with EPS, polyol antimicrobial and antifungal-producing properties. Bacterial strain screening was completed at both UCC and Teagasc.

At Teagasc, yoghurt shelf life studies were carried out with milk from cows fed on indoor diets, and outdoor grass-fed cows. At AgRes, New Zealand, a Teagasc post graduate student undertook application of exo-polysaccharide producing strains in yoghurts to determine their effect on texture. Product prototype development studies continued with the application of antimicrobial, polyol, and EPS producing strains in dairy fermentations, with the aim of producing products with extended shelf life, improved health qualities, and improved texture, respectively. The inclusion of a polyol producing strain aims to investigate if in situ production of mannitol has potential to produce a low calorific, sweetened fermented milk product for the dairy industry.

Using previously isolated bacteriocin (antimicrobial peptide) producers chosen for application within dairy products; a nisin, lacticin 3147, pediocin, and enterocin producer were applied in fermentations with the goal of producing bacteriocin enriched supernatants, which could be concentrated to a powder form and added to pasteurised milk for extended shelf life. Another experiment applied a commercially available additive containing nisin, Nisaplin, to extend the shelf life of pasteurised milk. Nisaplin at a concentration of 5% was found to prevent the growth of milk spoilage organisms to below detectable levels at day 0, 7, and 13 of shelf life. Further experiments examinined the effect of pure nisin A on the shelf life of pasteurised milk. Overall, bacteriocins may be used as an additive to extend the shelf life of pasteurised milk.

Analysis of wheat and oat bran extracts by the Polish Academy of Science (PAS) partner found antioxidant activity, determined using ABTS, FRAP, DPPH, and FRAP methods. Application of super-heated steam increase the antioxidant potential of wheat and oat bran and spent grain. Application of fermentation of wheat bran increase the antioxidant potential of wheat bran. The quantitative descriptive analysis (QDA) is a valuable tool for sensory analysis of fermented food. Fermented sausage salami is a good source of mineral compounds and C18:1 and C18:2 fatty acids. Addition of fermented wheat bran to bread and cookies increase their antioxidant potential.

University of Bologna (UniBo) partner conducted isolation and characterization of bacterial starter cultures that could be employed in salami production process. Salami prototype developed with selected started culture cocktail and 30 mg/kg NaNO2, relevant findings: Significant reduction of 1.5 log CFU/g di Clostridium spp. growth at the end of the ripening; Higher acidification rates, both, at the end of fermentation and at the end of ripening when compared with batches without starters; and acceptable colour intensity. The conclusions from this work were that new salami prototype was developed, which was fermented with new developed starter culture cocktail together with 30 mg/kg NaNO2. These prototype products combine microbiological safety, potential attractive colour for consumers and important reduction of carcinogenic nitrite concentration, thus improving food safety.

Fermented wheat bran ingredients were developed at TNO; The Netherlands that showed improved chemical composition related to higher amounts of soluble fibres and phenolics and in situ EPS production. Concept bakery products were produced with the fermented bran and compared to the commercial references. Biscuit products with fermented bran were developed with 30% sugar reduction and addition of oligosaccharides as sugar substitute showing similar sensory quality. Chemical analysis and in vitro testing confirmed substantial sugar reduction and lower predicted GI. Bread products with fermented bran showed substantial reduction in predicted GI. However, sensory properties of the developed bread product was remarkably different from the commercial reference.

AgResearch, NZ investigated how fermented milk (yogurt) alters digestion in vitro, and whether these responses differ with milk sourced from different species. Using the INFOGEST consensus protocol for simulated in vitro digestion we determined relative differences in the amount of peptides released within milk types, measured by gel filtration chromatography. Differing peptides between yogurt and milk of the same species were further analysed using scheduled precursor lists with LC-MS/MS for identification. Limited proteolysis occurred during fermentation of cow and sheep milk, whereas during in vitro digestion the fermented products broke down into peptides to a greater extent than did the milks. The amount of bioactive peptides identified was higher for yogurts compared to their milk counterparts, particularly peptides with anti-hypertensive properties. Overall these results suggest that fermented dairy products (e.g. yogurt) could bring cardiovascular benefits for consumers.