Silvia Grassi

Beer fermentation: monitoring of process parameters by FT-NIR and multivariate data analysis.

This work investigates the capability of Fourier-Transform near infrared (FT-NIR) spectroscopy to monitor and assess process parameters in beer fermentation at different operative conditions. For this purpose, the fermentation of wort with two different yeast strains and at different temperatures was monitored for nine days by FT-NIR. To correlate the collected spectra with °Brix, pH and biomass, different multivariate data methodologies were applied. Principal component analysis (PCA), partial least squares (PLS) and locally weighted regression (LWR) were used to assess the relationship between FT-NIR spectra and the abovementioned process parameters that define the beer fermentation. The accuracy and robustness of the obtained results clearly show the suitability of FT-NIR spectroscopy, combined with multivariate data analysis, to be used as a quality control tool in the beer fermentation process. FT-NIR spectroscopy, when combined with LWR, demonstrates to be a perfectly suitable quantitative method to be implemented in the production of beer.

Assessment of transduction of Escherichia coli Stx2-encoding phage in dairy process conditions.

In the environment, bacteriophages are regarded as natural vector for the transmission of Shiga-toxin genes among Shiga-toxin Escherichia coli strains. The possibility of transduction has been noticed in intestinal tract of various animals but experimental observations on this phenomenon in food processes are lacking. To investigate the transduction in milk at different temperature profiles and cell concentrations, an experimental plan including two different Stx(2)-phages (ϕGV2412 and ϕL34), induced respectively from E. coli O157:H7 181181/2 and E. coli O157:H7 EC34, and two recipient E. coli strains (CNCTC 6896, WG5) was performed. The donor strains were generated by lysogenization of CNCTC 6896 with ϕGV2412 and ϕL34 respectively. Spectinomycin resistance gene (aadA) was inserted into stx(2) operon in order to select transduced cells. Transductants were never observed at 4°C up to 24 h, whereas after a treatment at 37°C for 2 h and at 25°C for 22 h they were detected in 67% of the trials with a ratio of transduction varying from 1.13 10(-6) to 7.87 10(-8). A treatment at 48°C for 2 h followed by a second step at 25°C for 22 h showed an occurrence of transduction events in only 19% of cases with a ratio of transduction varying from 2.22 10(-7) to 2.67 10(-8). The generation of transductants and the spontaneous induction of phages in milk were not affected by initial or final concentration of the donor or recipient strains. The results show that transduction phenomenon occurs when the cells are metabolically active and it does not take place at low temperatures. Therefore, the maintenance of the chilling chain proved to be a main factor to prevent the spread of Stx-genes in dairy processes.

Monitoring of lactic acid fermentation process using Fourier transform near infrared spectroscopy

The aim of this paper was to evaluate the suitability of Fourier transform near infrared (FT-NIR) spectroscopy, combined with multivariate data analysis, to monitor milk lactic acid fermentation as an indication of possible deviations in quality parameters. Fermentation trials performed with different inocula (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus as single or in mixed cultures) at three incubation temperatures (37°C, 41°C and 45°C) were monitored by FT-NIR spectroscopy. Rheological and conventional quality parameters (microbial counts, pH, titratable acidity, lactose, galactose and lactic acid concentrations) were used as reference values to assess the findings with FT-NIR spectroscopy. Principal component analysis was applied to spectra to uncover molecular modifications. PC1 scores, rheological data and conventional quality parameter values were modelled as a function of fermentation time to designate critical points all along the process. Results showed that FT-NIR spectroscopy is a useful tool for real-time assessment of curd development during fermentation, offering crucial information in agreement with rheology and conventional quality parameters.

Handheld NIR device: A non-targeted approach to assess authenticity of fish fillets and patties

This study evaluates the reliability of a handheld NIR device in distinguishing fillets and patties of Atlantic cod (n = 80) from those of haddock (n = 90), in comparison with a FT-NIR benchtop spectrometer. The authentication issue was faced by Linear Discriminant Analysis (LDA) and Soft Independent Modelling of Class Analogy (SIMCA), pre-treating spectral data with different algorithms, and validating models both internally and externally. The best LDA models gave 100% correct classification in prediction. Sensitivity >65% and specificity >74% in prediction were calculated for the best SIMCA models. No significant differences (P > .05) were found between the two instruments by McNemar test. Thus, the work demonstrated that a handheld NIR device can be a simple, cost-effective, and reliable alternative to benchtop spectrometers in fish fillet and patty authentication. These important findings can help in improving commercial fraud fight, extending the possibility to authenticate fish species also in processed products.

The use of zonisamide for the treatment of psychiatric disorders: A systematic review

Objective Traditional pharmacotherapy has undoubtedly improved the outcome of patients with psychiatric disorders, but partial efficacy or poor tolerability persists in a number of these subjects. Among different compounds, zonisamide has been used to address unmet needs of standard pharmacotherapy. The purpose of the present article is to provide a review about the use of zonisamide for the treatment of psychiatric conditions. Methods A research in the main database sources has been conducted to obtain an overview of the use of zonisamide in psychiatric disorders or associated conditions (obesity and smoking cessation). Results Most available data indicate the possible effectiveness of zonisamide for the treatment of acute phases of bipolar disorder, binge-eating disorder (BED), alcohol misuse, and obesity. A further assessment of the safety and tolerability of zonisamide is made necessary by the fact that, with the exception of BED, for all other disorders at least some data come from studies with combined pharmacological therapies. Conclusions Zonisamide may have some utility, especially as an adjunctive therapy, for the management of acute phases and weight gain in bipolar disorder and for prevention of alcohol misuse. Preliminary evidence indicates zonisamide as a candidate compound for the treatment of BED and obesity. However, open-label design and small sample sizes of most available studies prevent from drawing sound conclusions about the utility of this compound in psychiatry.

Effect of low-protein diets in heavy pigs on dry-cured ham quality characteristics

The present work aimed at evaluating if heavy pig low-protein diets balanced for amino acid (AA) profile affect the quality characteristics of dry cured hams. To the aim, 40 hams obtained by Italian Duroc×Italian Large White pigs fed three different dietary crude protein and indispensable AA levels were compared with those obtained by a conventional Parma ham Protected Designation of Origin diet (C). No physico-chemical (aw, pH), chemical (gross composition, NaCl, lipid peroxidation, non-protein nitrogen, total volatile bases) or sensory characteristics of hams were systematically affected by the administered diet, animal sex or their interaction with the exception of total and subcutaneous fat (the latter measured by an image analysis procedure). Considering gilts, low-protein diets resulted in samples with higher fat content and subcutaneous fat thickness with respect to hams obtained with C diet. In conclusion, low protein diets in the finishing phase of pig breeding could reduce the environmental impact due to nitrogen excretion without significantly affecting ham quality.

Sex Steroids and Major Psychoses: Which Role for DHEA-S and Progesterone?

Objective: Endocrine pathways seem to play a role in the etiology of major psychoses. The identification of biomarkers associated with psychotic symptoms in schizophrenia (SKZ) and mood disorders would allow the identification of high-risk subjects for delusions and hallucinations. The aim of this study was to evaluate dehydroepiandrosterone sulfate (DHEA-S) and progesterone plasma levels in drug-free patients with major psychoses and their relation with the diagnosis and history of psychotic symptoms. Methods: Eighty-nine consecutive drug-free male inpatients with SKZ or mood disorders were recruited, and DHEA-S and progesterone plasma levels were measured. The groups, divided according to pathological/normal-range hormone levels, were compared in terms of clinical variables using χ2 tests with Bonferronis corrections or multivariate analyses of variance. The same analyses were performed for groups divided according to the presence/absence of lifetime psychotic symptoms. Binary logistic regression analysis was performed using hormone levels as independent variables and history of lifetime psychotic symptoms as a dependent one. Results: A higher number of patients with abnormal DHEA-S levels was found to have a family history of major depressive disorder (p < 0.05). Higher DHEA-S levels (F = 8.31; p = 0.005) were found in patients with a history of psychotic symptoms. In addition, binary logistic regression confirmed that DHEA-S levels were associated with a higher probability of lifetime psychotic symptoms (p = 0.037). Conclusions: Our results confirm previous data about the role of endocrine factors in the etiology of major psychoses. A high DHEA-S level might be a risk factor for psychotic symptoms. Studies with larger samples are needed to confirm these data.

Cognitive correlates of neuroimaging abnormalities in the onset of schizophrenia: A case report

Increasing evidence shows that cognitive impairment and brain abnormalities can appear early in the first episodes of schizophrenia, but it is currently debated how brain changes can correlate with clinical presentation of schizophrenic patients. Of note, this report describes the case of a young schizophrenic male presenting parietal magnetic resonance/positron emission tomography abnormalities and cognitive impairment, documented by specific neuropsychological tests. In our knowledge only few studies have investigated if neuropsychological abnormalities could be concomitant with both structural and functional neuroimaging. This case shows that impairment in specific cognitive domains is associated with structural/functional brain abnormalities in the corresponding brain areas (frontal and parietal lobes), supporting the hypothesis of disconnectivity, involving a failure to integrate anatomical and functional pathways. Future research would define the role of cognitive impairment and neurodegeneration in psychiatric nosography and, in particular, their role in the early phases of illness and long-term outcome of schizophrenic patients.

Near infrared and mid infrared spectroscopy in oenology: determination of main components involved in malolactic transformation

Introduction T here are two main fermentations associated with the winemaking process. The first is an alcoholic fermentation conducted by yeasts while the second is a secondary fermentation, called malolactic fermentation (MLF) performed by lactic acid bacteria (LAB) specifically from the genera Oenococcus, Lactobacillus and Pediococcus. MLF is a biotransformation usually defined as the conversion of malic acid to lactic acid and CO2, that contributes to deacidification, microbial stability and modification of the aroma profile. Winemakers usually rely on spontaneous MLF arising from indigenous LAB occurring on grape surfaces, grape must together with the cellar environment, including barrels and winery equipment. For this reason spontaneous MLF is often unpredictable. Commonly it occurs after completion of alcoholic fermentation, when the wine conditions are favourable for the growth of lactic acid bacteria but it may start after long delays. Even with the use of commercial starter cultures, complete and successful MLF is not always guaranteed, especially under difficult wine conditions (i.e. low pH, high ethanol and SO2 concentrations). 1