engleski

ORGANIC CEREAL SPECIES DIVERSITY AND CHARACTERIZATION OF THEIR FERMENTATION AND ANTIMICROBIAL ACTIVITY

In recent years, due to a current focus on “healthy” food and a healthy lifestyle, the market for organic cereals has grown rapidly. Organic farming avoids the use of synthetically compounded fertilizers, pesticides or growth regulators, and prefers crop rotations, crop residues, animal and green manures, mechanical cultivation and biological pest control. Because of that, one can presume that the organic farming preserves biodiversity and that the organic products can be the source of different microbial species suitable for food industry. In this study the species diversity in organically grown wheat, spelt and rye was investigated. Identification was based on mass spectrometry using a Microflex LT ™ MALDI-TOF instrument. Also, fermentative and antimicrobial activities of identified species were determined in order to apply these microorganisms to sourdough fermentation. The fermentation products (lactic, acetic, formic and fenil-lactic acid) were determined by high pressure liquid chromatography, while the antimicrobial activity was determined using an overlay agar method. The results showed that the flour samples had a rich microflora. A total of 16 lactic acid bacteria and Candida crusei were isolated. Wheat flour showed less biodiversity than the rye and spelt flour. The most common genera in the tested flour were Lactobacillus and Enterococcus. Isolated Lactobacillus farciminis, Pediococcus pentosaceus, Leuconostoc citreum and Lactobacillus brevis showed the best fermentation activity. Lactobacillus brevis, Pediococcus pentosaceus, Weissella cibaria and Lactobacillus farciminis showed significant antimicrobial activity against A. niger and Penicillium sp.

Lactobacillus; organic cereals; sourdough; species diversity; spelt

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