Cheese-making Plants Research Articles

Free amino acids and volatile compounds in an ewe’s milk cheese as affected by seasonal and cheese-making plant variations

Analysis of free amino acids (FAAs) and volatile compounds in Roncal cheese throughout the cheesemaking seasons was carried out. The possible relationships between them were studied. Also, the influence of two cheesemaking plants was analysed. Total FAAs was 30–50% higher in cheeses made in summer than in cheeses made in either winter or spring. The main amino acids, which accounted for about 69% of the total FAAs, were Glu (20%), Leu (14%), Val (10%), Lys (9%), Phe (6%), and Pro and Ile (about 5% each). Besides six miscellaneous components, the 64 volatile components identified comprised nine hydrocarbons, 16 alcohols, two sulfur-containing compounds, seven aldehydes, eight ketones, six acids and 10 esters. Season was the first factor affecting the concentration of FAAs, and dairy plant was the principal one influencing the level of volatile compounds. Significant interactions between both factors found for the volatile components made very difficult to correlate their formation with the precursor amino acids.

MONITORING TASTE PANEL EFFICIENCY DURING EVALUATION OF THE SENSORY QUALITY OF RONCAL CHEESE

ABSTRACTA statistical study was performed on the scores awarded by a taste panel over a full Roncal cheese manufacturing season. The panel evaluations were part of a quality control program carried out on that cheese under the auspices of the Appellation of Origin for Roncal cheese by panelists previously trained and qualified as proficient. Analysis of variance and factor analysis were performed to examine variability for the different attributes and the influence of such factors as cheesemaking plant and the manufacturing season and also to monitor panel reliability. The results indicated that the attributes associated with the descriptor “characteristic” had the highest variability; these attributes were characteristic odor, characteristic aroma, characteristic texture, characteristic flavor, and characteristic aftertaste. Cheesemaking plant was the factor that had the greatest effect on variability. Factor analysis and exploratory box plot data analysis were used to detect discrepancies between individual assessors and the rest of the panelists.

The SBR process: an efficient and economic solution for the treatment of wastewater at small cheesemaking dairies in the Jura mountains

The small cheesemaking plants in the Jura Mountains (N.E. France) need self-contained solutions for treating their wastewater. Any solution must suit the characteristics of the effluent produced by these small production units and be simple, robust and financially feasible in regard to both capital and running costs. Given this context, a technique based on an SBR was recommended and the operations of the first treatment plant established on an industrial scale, monitored for the first year, with particular attention paid to operating constraints. The results obtained show that the SBR is, from a technical point of view, perfectly adapted to treating cheese production wastewater, with purification levels at 97.7% for total COD and 99.8% for BOD5. In the course of this study, it has been shown that the SBR process, thanks to its simple design and operation, can easily be run by the cheesemaker who will need to devote a minimum of time to it. Furthermore, with treatment costs of around 2 centimes (0.33 US cent) per litre of milk delivered, the SBR process meets perfectly both the technical and financial conditions for treatment as laid down by the Federation of Cooperatives of the Doubs and Jura départements.

Survey of the Microbiological Quality of Adult Bovine Rennet Extracts

Sixty-nine samples of liquid bovine rennet extract from several cheese-making plants were examined for microbiological quality. Wide differences were observed in the microbiological results, as well as in the pH, which ranged from 4.0 to 6.5, reflecting the manufacturing practices and sanitary conditions. The highest level of contamination was always caused by sporulated bacteria, both aerobic and anaerobic. Coliforms, considered to be enteric indicator bacteria were not detected, although halotolerant bacteria were found.