MICROBIOLOGICAL EVOLUTION OF DACIA SAUSAGE, A DRY CURED ROMANIAN SAUSAGE

Selected starter cultures were used to produce the traditional Romanian dry cured sausage, Dacia. A control sausage was produced without starter culture (sausage A), one with L. sakei CECT 5964 and S. equorum SA25 (sausage B) and one with L. sakei CECT 5964, S. equorum SA25 and L. acidophilus CECT 903 (sausage C). Samples from each batch of sausages were taken at 0 (mix before stuffing), and after 2, 4, 7, 14, 21 and 28 days of ripening. Counts of total aerobic mesophilic flora, lactic acid bacteria, salt tolerant flora, and Enterobacteriaceae and some physical-chemical parameters (moisture, NaCl, pH and aw values) were determined. High microbial counts (log CFU) were observed with values at the end of ripening period: for lactic acid bacteria 9.77 (A), 11.47 (B) and 11.19 (C); for total aerobic mesophilic flora 9.89 (A), 11.38 (B) and 11.30 (C); for salt tolerant flora 4.45 (A), 5.31 (B) and 5.27 (C). The starter cultures had a significant inhibitory effect on Enterobacteriaceae counts (log CFU), values at the end of ripening period being 1.32 (A), 0.33 (B) and not detected (C). A significant decrease in the pH values is observed until the seventh day of ripening, showing a slight, but progressive increase after the 14th day of ripening. Results show that the production and ripening process in a pilot scale chamber under controlled conditions contributes in obtaining safe and homogeneous products

Thermally driven interactions between β-lactoglobulin and retinol acetate investigated by fluorescence spectroscopy and molecular modeling methods

International audienceAbstractWhey proteins have important functional properties as it can bind a wide range of bioactive molecules. In this study, the complexation of β-lactoglobulin with retinol at alkaline pH was investigated. The fluorescence spectroscopy was used to determine the temperature dependent behavior of the β-lactoglobulin-retinol acetate (βLG-RET) ensemble. The pattern of protein unfolding in the temperature range of 25–85 °C was followed mainly considering the exposure of tryptophan (Trp) residues. The βLG-RET complex appeared rather stable in the 25–60 °C range, while further increase of the temperature caused partial unfolding. The anisotropy measurements indicated a more flexible conformation at temperature increase up to 80 °C. In addition, the in silico approach was used to complement the experimental results. Important changes in the interaction surface were observed after performing molecular dynamics simulations. The temperature increase caused important rearrangements of the amino acids of the EF loop involved in the interaction with the retinol molecule, which got twisted. These atomic level events induced a significant increase of the affinity between βLG and retinol. This study offers useful information on the potential use of βLG as a carrier for biologically active compounds in order to obtain food products with desired functionalities

Influence of spice and wine based marinades on bovine Biceps femoris muscle tenderness

Fresh beef slices were marinated by immersion in marinades based on dry red wine, lime-tree honey, salt, spices and seasoning plants as thyme (Thymus vulgaris), marjoram (Majorana hortensis), garlic (Allium sativum) and horseradish (Armoracia rusticana). Control samples were prepared without marinating treatment but packed and stored in the same conditions as marinated samples. After marination, meat pieces were packed under vacuum and stored at 4°C for 12 days. The combined effects of spices and marination on beef tenderness were evaluated by monitoring pH evolution, the protein and collagen degree of hydrolysis and tenderness. Experimental data indicated that marination weaken beef meat structure, producing improvement of functional properties of adult beef. Marinades use lead for an increase in the protein nitrogen fraction, free amino acids and hydroxyproline contents in boiled beef cuts. A significant increase in tenderness by hardness measurement was observed in the samples marinated and boiled, as compared with the control.Key words: Acidic marination, beef meat, marinating time, meat hardness, pH

Volatile compounds analysis of Dacia sausage, a traditional Romanian dry cured sausage

Three batches of Dacia sausage were produced as follows: one without starter culture and two with a mix of starter cultures. Volatiles were extracted by a purgeand- trap method and analyzed by gas chromatographic/mass spectrometry. Approximately 43 compounds were identified. The substances identified belong to: aldehydes, alcohols, ketones, hydrocarbons, esters, acids, furans. Results indicated that the most abundant class of chemical substances in flavor at the end of the ripening process was esters, followed by aldehydes, hydrocarbures and terpenes. This could only indicate the high microbial esterification activity that took place in the batches. It was possible to differentiate between the three sausages applying a discriminant analysis