Preliminary Assessment of Visible, Near-Infrared, and Short-Wavelength-Infrared Spectroscopy with a Portable Instrument for the Detection of Staphylococcus aureus Biofilms on Surfaces.

Bacterial biofilms constitute a major source of sanitary problems and economic losses in the food industry. Indeed, biofilm removal may require intense mechanical cleaning procedures or very high concentrations of disinfectants or both, which can be damaging to the environment and human health. This study assessed the efficacy of a technique based on spectroscopy in the visible, near-infrared, and short-wavelength infrared range for the quick detection of biofilms formed on polystyrene by the pathogenic bacterium Staphylococcus aureus. To do that, biofilms corresponding to three S. aureus strains, which differed in biofilm-forming ability and composition of the extracellular matrix, were allowed to develop for 5 or 24 h, representing an active formation stage and mature biofilms, respectively. Spectral analysis of the samples, corresponding to three biological replicates of each condition, was then performed by using a portable device. The results of these experiments showed that partial least-squares discriminant analysis of the spectral profile could discriminate between surfaces containing attached bacterial biomass and noninoculated ones. In this model, the two first principal components accounted for 39 and 19% of the variance and the estimated error rate stabilized after four components. Cross-validation accuracy of this assessment was 100%. This work lays the foundation for subsequent development of a spectroscopy-based protocol that allows biofilm detection on food industrial surfaces.

Objective assessment of knife sharpness over a working day cutting meat.

Knife sharpness is one of multiple factors involved in musculoskeletal disorders in industrial meat cutting. The aim of this study was to objectively evaluate, in real working situations, how knife sharpness changed over a working day cutting meat, and to analyse the impact of sharpening, steeling and meat-cutting activities on these variations. Twenty-two meat-cutting workers from three different companies participated in the study. The methods included measurements of knife sharpness in relation to real work situations and consideration of the way meat-cutting and sharpening operations were organised. Results showed that the type of meat-cutting activities, the steeling strategy adopted by the worker, including the types of tool used, and the overall organisation of the sharpening task all had a significant influence on how knife sharpness evolved over a 2-h period and over an entire working day. To improve MSD prevention, sharpening and steeling operations should not be considered as independent activities, but taken into account as a continuity of working actions. Appropriate assessment of knife sharpness by meat cutters affects how they organise meat-cutting and sharpening tasks.

Quantification of caffeine, trigonelline and nicotinic acid in espresso coffee: the influence of espresso machines and coffee cultivars.

Caffeine, trigonelline and nicotinic acid are important bioactive constituents of coffee. In this work, the combination of different water temperatures and pressures in the settings of the espresso coffee (EC) machine was evaluated, to assess how these factors influence how effectively caffeine, trigonelline and nicotinic acid are extracted from both Arabica and Robusta samples. The proposed analytical method, based on a high performance liquid chromatography (HPLC) system coupled to a variable wavelength detector (VWD), showed good linearity (R²> 0.9985) and good recoveries (71-92%); after validation for three monitored compounds, the method was used to analyze 20 commercial samples. The combination of a temperature of 92 °C and pressure at 7 or 9 bar seems to be the ideal setting for the most efficient extraction of these compounds and consequently for their intake; the compound extracted in the greatest quantity was caffeine, which was in the range of 116.87-199.68 mg in a 25 ml cup of coffee.

High-speed weight estimation of whole herring (Clupea harengus) using 3D machine vision.

UNLABELLED: Weight is an important parameter by which the price of whole herring (Clupea harengus) is determined. Current mechanical weight graders are capable of a high throughput but have a relatively low accuracy. For this reason, there is a need for a more accurate high-speed weight estimation of whole herring. A 3-dimensional (3D) machine vision system was developed for high-speed weight estimation of whole herring. The system uses a 3D laser triangulation system above a conveyor belt moving at a speed of 1000 mm/s. Weight prediction models were developed for several feature sets, and a linear regression model using several 2-dimensional (2D) and 3D features enabled more accurate weight estimation than using 3D volume only. Using the combined 2D and 3D features, the root mean square error of cross-validation was 5.6 g, and the worst-case prediction error, evaluated by cross-validation, was ±14 g, for a sample (n = 179) of fresh whole herring. The proposed system has the potential to enable high-speed and accurate weight estimation of whole herring in the processing plants. PRACTICAL APPLICATION: The 3D machine vision system presented in this article enables high-speed and accurate weight estimation of whole herring, thus enabling an increase in profitability for the pelagic primary processors through a more accurate weight grading.

Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives.

Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives, in the absence or presence of food debris from meat, fish and vegetables and at temperatures of 10, 25 and 37 degrees C was investigated. The pathogen survived best at 10 degrees C, and better at 25 degrees C than at 37 degrees C on both conveyor belt materials. The reduction in the numbers of the pathogen on belt material with antimicrobial additives in the first 6h at 10 degrees C was 0.6 log unit, which was significantly higher (P<0.05) than the reduction of 0.2 log unit on belt material without additives. Reductions were significantly less (P<0.05) in the presence of food residue. At 37 degrees C and 20% relative humidity, large decreases in the numbers of the pathogen on both conveyor belt materials during the first 6h were observed. Under these conditions, there was no obvious effect of the antimicrobial substances. However, at 25 degrees C and 10 degrees C and high humidity (60-75% rh), a rapid decrease in bacterial numbers on the belt material with antimicrobial substances was observed. Apparently the reduction in numbers of L. monocytogenes on belt material with antimicrobial additives was greater than on belt material without additives only when the surfaces were wet. Moreover, the presence of food debris neutralized the effect of the antimicrobials. The results suggest that the antimicrobial additives in conveyor belt material could help to reduce numbers of microorganisms on belts at low temperatures when food residues are absent and belts are not rapidly dried.

A cost and returns evaluation of alternative dairy products to determine capital investment and operational feasibility of a small-scale dairy processing facility.

This study examines the economic feasibility of 50- and 500-cow dairy processing facilities for fluid milk, yogurt, and cheese. Net present value and internal rate of return calculations for projected costs and returns over a 10-yr period indicate that larger yogurt and cheese processing plants offer the most profitable prospects, whereas a smaller yogurt plant would break even. A smaller cheese plant would have insufficient returns to cover the cost of capital, and fluid milk processing at either scale is economically infeasible. Economic success in processing is greatly contingent upon individual business, financial management, and marketing skills.