A ready-to-use semi-liquid starter culture for extending the shelf-life of baked products.

OBREGOZO, M; GEREZ, C. L.; TORINO, M.I.; FONT DE VALDEZ, G

Madrid, España

Congreso; 13th ICC Cereal and Bread Congress. Cereals in the 21st century: present and future.; 2008

International Association for Cereal Science and Technology (ICC) y Asociación Española de Técnicos Cerealistas (AETC).

The sourdough-based fermentation technology opens new perspectives for innovative backed products, including the use of specific lactic acid bacteria (LAB) strains as starter culture or as bakery ingredients to improve the quality and/or the shelf-life of baked goods (Lacaze et al., 2007). Fungal bread spoilage is a major detrimental phenomenon in the baking industry, which is overcame by using high concentration of chemical additives. The European Community regulations allow concentration of calcium propionate (CP) in bread manufacture up to 0.3% because of its potential tumorigenic and neurobiological effects (MacFabe et al., 2007). In Argentina, the upper limit for CP is 0.4%. In previous studies, a fermented semi-liquid starter culture (slurry) containing the strain Lactobacillus plantarum CRL778 proved to have antifungal activity and to be effective in packed bread. In this work, a mixed bio-strategy was set down for extending the shelf-life (usually 8-days) of packed bread and eventually for reducing the use of chemical conservatives. Lb. plantarum CRL778 was inoculated (20% v/v) to a mixture of wheat flour, milk, sucrose and tap water. The mixture was fermented under agitation at 37ºC for 12 h. The obtained slurry was used as ingredient (40%) in bread manufacture combined with different concentrations of CP (0.1-0.4%) (SL-bread). Breads elaborated only with CP (CP-bread) were used as standards for comparison. The loaves were backed (180ºC/45 min) and let cooled at room temperature. The bread loaves were surface sprayed with a conidial suspension of Penicillium sp., packed into polyethylene bags, and stored at 25ºC. The packed breads were observed daily for visible mould growth; the shelf life was defined as the time (in days) for moulds to become visible. Three loaves of each bread type were evaluated in two independent assays. The conservation of CP-breads was 4 days (0.1 % CP) and 8 days (0.4% CP). Likewise, the bread shelf life was ca. 5 days with the slurry alone but it could be extended to 17 and 30 days when combining the slurry (40%) and CP (0.3 or 0.4%) respectively. These results are promising for reducing chemical additives without affecting the food quality. References: - Lacaze G, Wick M, Cappelle S: Emerging fermentation technologies: Development of novel sourdoughs. Food Microbiology (2007), 24: 155-160. - MacFabe DF, Cain DP, Rodriguez-Capote K, Franklin AE, Hoffman JE, Boon F, Taylor AR, Kavaliers M, Ossenkopp KP: Neurobiological effects of intraventricular propionic acid in rats: Possible role of short-chain fatty acids on the pathogenesis and characteristics of autism spectrum disorders. Behavioral Brain Research (2007), 176, 149-169.