M: Food Microbiology & Safety Improved Sauerkraut Production with Probiotic Strain Lactobacillus plantarum L4 and Leuconostoc mesenteroides LMG 7954 Jasna Beganovi´ c, Andreja Leboˇ s Pavunc, Kreˇ simir Gjuraˇ ci´ c, Marina ˇ Spoljarec, Jagoda ˇ Suˇ skovi´ c, and Blaˇ zenka Kos Abstract: Probiotic strain Lactobacillus plantarum L4 and strain Leuconostoc mesenteroides LMG 7954 were applied for the controlled fermentation of cabbage heads. The parameters of the controlled and spontaneous fermentations, including antimicrobial effect of cabbage brines obtained at the end of both fermentations, were monitored. To check out the influence of starter culture strains, 10 randomly chosen lactic acid bacteria, isolated at the end of controlled cabbage heads fermentation were identified by API 50CHL test, and the presence of the probiotic culture was confirmed by Pulsed Field Gel Electrophoresis. The starter cultures applied for cabbage heads fermentation allowed lowering of NaCl concentrations from 4.0% to 2.5% (w/v), considerably accelerated fermentation process by 14 d, and improved the product quality. The produced sauerkraut heads are considered probiotic product as viable probiotic cells count in final product was higher than 10 6 colony-forming units (CFU) per gram of product. Keywords: controlled fermentation, Lactobacillus plantarum, Leuconostoc mesenteroides, probiotics, sauerkraut Practical Application: The results of this research could be applied in the production of fermented cabbage heads with added functional (probiotic) value and with lower NaCl concentration with expected shortened fermentation time. This could not only be of economic but also of ecological importance. Introduction Modern consumers are showing continuously a remarkable interest in functional foods with health-promoting properties. Nowadays, developments in functional food are mostly associ- ated with probiotics (Leroy and DeVuyst 2004). Most of probiotic microorganisms are characterized from lactic acid bacteria (LAB) species that are traditionally applied in fermented dairy prod- ucts, but are also being increasingly introduced into drinks and fermented vegetables as functional starter cultures (Shah 2001; Mattila- Sandholm and others 2002; Yoon and others 2006; Kos and others 2008; Leboˇ s and others 2008). Functional starter cul- tures are defined as starters that possess at least one inherent, func- tional property, aimed at improving the quality of the end product (De Vuyst 2000). Cabbage is a cruciferous vegetable, rich in minerals, vitamin C, dietary fibers, and phytochemicals (Yoon and others 2006). The most common among cabbage products is sauerkraut, usually pro- duced by spontaneous fermentation. Fermentation involves many physical and chemical changes and a rapid turnover of LAB species that influence the quality of the product. The dominant species, present in the fermentation, shift within 1 wk from less acid- MS 20100825 Submitted 7/23/2010, Accepted 12/3/2010. Authors Beganovi´ c, Pavunc, ˇ Suˇ skovi´ c, and Kos are with Dept. of Biochemical Engineering, Faculty of Food Technology and Biotechnology, Univ. of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia. Author Gjuraˇ ci´ c is with Yeast Molecular Genetics, ICGEB, AREA Science Park, Padricano 99, 34012 Trieste, Italy. Author ˇ Spoljarec is with Prehrana Inc., Ulica Biˇ skupeˇ cka 56, 42 000 Varaˇ zdin, Croatia. Direct inquiries to author Kos (E-mail: bkos@pbf.hr). tolerant heterolactic to more acid-tolerant homolactic fermenting LAB species (Fleming and others 1995). However, the quality of sauerkraut produced by spontaneous fermentation strongly varies depending on substrate and natural microbial population. Salt con- centration and fermentation temperature can also affect the growth of the naturally present microorganisms and the sensory properties of the sauerkraut (Wiander and Ryhanen 2005; Pe´ nas and oth- ers 2010). Thus, an application of well characterized functional starter cultures could minimize quality variation and allow func- tional food production. Recent researches have shown potential benefits of using starter cultures in low-salt sauerkraut fermenta- tions (Wiander and Ryhanen 2005; Johanningsmeier and others 2007). In the fermentation of cabbage heads, the added salt con- centrations must be much higher (4% NaCl) than in shredded cabbage fermentation (1.5% NaCl). Tolonen and others (2002) compared shredded cabbage inoculated with a mixed culture of Leuconostoc mesenteroides and Pediococcus dextrinicus with shredded cabbage fermented without a starter culture using a mixture of different salts and observed a more rapid decline in pH and the completion of fermentation with added starter culture. In this research, 2 starter cultures were applied for sauerkraut heads fermentation: Ln. mesenteroides LMG 7954, originally iso- lated from sauerkraut, important for the 1st phase of the fermenta- tion, and Lactobacillus plantarum L4, which is the most acid-tolerant species, important for the 2nd phase of fermentation. In sponta- neous sauerkraut fermentation, Ln. mesenteroides initiates the fer- mentation, followed by growth of other LAB, mainly Lb. brevis, P. pentosaceus, and Lb. plantarum species, among which Lb. plantarum is responsible for the 2nd phase of fermentation and high acidity of the produced sauerkraut. Lb. brevis produces a harsh vinegar-like C  2011 Institute of Food Technologists R  M124 Journal of Food Science  Vol. 76, Nr. 2, 2011 doi: 10.1111/j.1750-3841.2010.02030.x Further reproduction without permission is prohibited