Presence of biogenic amines in a traditional salted Italian cheese

Asino cheese is a traditional Italian cheese ripened in a special dilute brine (salmuerie), mixed with whey, milk and milk cream. The aim of this work was to ascertain whether this processing technology can influence amine production. The study demonstrated that biogenic amine content increased gradually in the Asino cheese during the soaking phase in brine. Moreover, the biogenic amine content of the salmuerie was very high and the salmuerie and the Asino cheese had a similar relative profile in amine content. These results suggested that the biogenic amines migrate from the brine into the cheese as a result of the concentration differential existing between the two systems.     

INFLUENCE OF DIFFERENT CASINGS ON SALAMI PRODUCED WITH MEAT FROM BUFFALO AND PODOLIAN CATTLE

ABSTRACT

The effect of different casings on the quality of new types of salami from buffalo and Podolian young bull meat was investigated. To this aim, three casings were used: a natural casing (NC), a modified natural casing (MNC) and a synthetic casing (SC). Their effects on processed meat were analyzed by evaluating salami quality at the end of the ripening time. Nutritional properties, microbial loads, pH, color parameters, texture and sensory properties were assessed. Moreover, the mechanical properties of the casings were measured. Results highlighted that both meat were suitable to produce salami; better results in terms of saturated and polyunsaturated fatty acids were recorded with Podolian meat. The NC and the SC exerted similar mechanical properties, very different from those of the MNC. The superior properties of the NC in terms of texture and color characteristics conferred to the fermented sausages could allow suggesting this casing as the most recommended solution to package unusual salami.

PRACTICAL APPLICATIONS

The increasing consumer interest in products with high energetic and nutritional value, authentic, tasty, rich in protein and low in lipid and cholesterol content gives rise to promote consumption of alternative meat to pork. Therefore, the influence of different casings on salami produced by boneless buffalo and young bull could be of crucial importance for industry that cares about consumer satisfaction.     

Characterisation and evolution of grape polyphenol profiles of Vitis vinifera L. cv. Tannat during ripening and vinification

Background and Aims: Changes in different polyphenol families during grape ripening and vinification were determined in Tannat grapes. This was done to establish a polyphenol profile for Tannat grapes during ripening and for young wines. Methods and Results: We demonstrated, by high‐performance liquid chromatography with diode array detection and mass spectrometry (HPLC‐DAD‐MS) analysis, that the content of flavan‐3‐ols in Tannat seeds was higher than that reported for a large number of other grape varieties analysed. Forty per cent of the total flavan‐3‐ols in seeds were galloylated compounds, whereas the flavan‐3‐ol profile in skins was characterised by the absence of galloylated forms. Prodelphinidins in skins ranged between 30 and 35% with very low values for epigallocatechin. Epicatechin gallate was not detected in Tannat wine and galloylated forms represented a low percentage of total flavan‐3‐ols. Tannat grapes had very high concentrations of anthocyanins in skins with levels increasing during ripening. Eleven phenolic acids were identified in Tannat grape skins and wines, but only gallic and protocatechuic acids were found in the seeds. Conclusions: Tannat wines were shown to have one of the highest levels of phenolic compounds reported for vinifera grape varieties. The profiles for different polyphenol families present in Tannat grapes (skins and seeds) and wines were determined. Significance of the Study: The results presented will help to better understand the phenolic winemaking potential of this variety and its functional properties within food chemistry.     

High-gain feedback in non-linear control systems†

High-gain state and output feedback are investigated for non-linear control systems with a single additive input by using singular perturbation techniques.

Classical approximation results (Tihonov-like theorems) in singular perturbation theory are extended to non-linear control systems by defining a composite additive control strategy, a control-dependent fast equilibrium manifold and non-linear change of coordinates.

Those tools and an appropriate change of coordinates show that high-gain state feedback and variable structure control systems can be equivalently used for approximate non-linearity compensation in feedback-linearizable systems.

Next the effect of high-gain output feedback is shown to be related to the strong invertibility property and the relative order of invertibility. For strongly invertible systems the slow reduced subsystem coincides with the dynamics of the inverse system when zero input is applied and with the unobservable dynamics when a certain input-output feedback-linearizable transformation is applied.     

Caffeine Inhibition of Ochratoxin A Production

The effect of caffeine and theobromine on growth and ochratoxin A production by Aspergillus ochraceus was determined using microbiological medium. Caffeine produced a small decrease in growth, while reducing ochratoxin production as much as 98%. Theobromine had relatively little effect on growth or ochratoxin production. Screening of caffeine for its effect on the growth of a number of Aspergillus and Penicillium species indicated that caffeine may have biological activity against a variety of mycotoxigenic molds.     

Occurrence and characterization of Staphylococcus aureus isolated from raw milk for cheesemaking

Fifty-four samples of raw milk for cheesemaking were tested for the presence of Staphylococcus aureus . Multiplex polymerase chain reactions were performed to identify presumptive isolates and the presence of enterotoxin-coding genes sea-see . The strains were tested for antibiotic resistance. Eighty strains were identified as S. aureus and 31 of these carried one or more enterotoxin genes ( sea-see ). Resistance to eritromycin, penicillin and ampicillin was widespread among isolates . Staphylococcus aureus in raw milk for cheesemaking may constitute a risk with respect to staphylococcal food poisoning from raw milk products.     

Direct approach to almost disturbance and almost input-output decoupling

A direct solution to the almost input-output and disturbance decoupling problem is given. The approach is based on a new canonical form for linear systems—which is obtained in a fully constructive way—together with some elementary approximation results. The solution is given in the form of an explicit feedback law, parameterized by a scalar ε. By letting ε go to zero, the accuracy of the resulting approximate solution can be improved to any desired degree.     

Use of Landsat and Seasat data as a tool in kinematic analysis

Abstract

Brittle and plastic deformations of the Tunisian Atlas were studied using Landsat data, Seasat synthetic aperture radar (SAR) data and field surveys. Locations of structural stations were guided by detailed analysis of images and computer compatible tapes (CCTs). Digital processing and enlargements at scales of 1:100 000 and 1:200 000 allowed the recognition of several fault displacements and strata dips, followed by field checks. This paper presents an original and complete structural map of the Tunisian Atlas for the first time, showing the en échelon pattern of the major folds and the numerous fault systems.The kinematic evolution of the Tunisian Atlas is shown through the integration of remotelysensed, microtectonic and focal mechanism data. Circular folds, Riedel shears, reverse and tear faults in the Northern Atlas and asymmetrical folds and strikeslip and reverse faults in the Southern Atlas are framed in a new model involving wrench tectonic and induced transpression. Four principal deformational phases, developed from the Palaeogene to the Holocene, have been recognized and discussed. Finally, stress field evolution is presented and compared with plate tectonic knowledge of the Western Mediterranean Basin. The usefulness of remotely-sensed data for this kind of work, with special reference to arid regions, is stressed in this study.     

Do not forget the breakdowns and the maintenance operations in FMS design problems!

The increase in the number of flexible manufacturing systems is nowadays one of the main trends in the mechanical industry. Because of the complexity of such systems, careful studies are required to make the appropriate design choices in order to avoid an economical disaster. The queueing network theory provides adequate tools to deal with these problems.

Most of the analytical models neglect the breakdowns and the maintenance operations which disturb the smooth working of the factory.

This paper presents an easy way of modelling these perturbations so that they can be taken into account when evaluating the performances of an FMS (production rate, machine utilization,...). A comparison between the analytical results and the ones obtained by simulation demonstrates the accuracy of the proposed modelling technique.