Papers by Stefania Balzan
To study proteomic changes involved in tenderization of bovine Longissimus dorsi four Charolaise ... more To study proteomic changes involved in tenderization of bovine Longissimus dorsi four Charolaise heifers and four Charolaise bull's muscles were sampled at slaughter after early and long ageing (2-4°C for 12 and 26 days respectively). Descriptive sensory evaluation of samples were performed and their tenderness evaluated by Warner-Bratzler shear force test. Protein composition of fresh muscle and of meat aged was analysed by cartesian and polar 2-D electrophoresis. Student's t-test and Ranking-PCA analyses were performed to detect proteomic modulation, and the selected protein spots were identified by nano-HPLC-Chip MS/MS. This research has demonstrated that there are no differences between proteomic patterns of male and females Longissimus dorsi muscle, and that the extension of ageing beyond 12 days, did not brings any concrete advantage in terms of sensory quality. Furthermore, the data presented here demonstrated that meat maturation caused changes of the abundance of proteins involved in metabolic, structural, and stress related processes.
This study aimed at verifying if computer image analysis could represent a good technique to disc... more This study aimed at verifying if computer image analysis could represent a good technique to discriminate between reared and wild European sea bass (Dicentrarchus labrax). Images were acquired from sea bass of known origin (n=47 reared and n=13 wild). Images were taken using a digital camera and standardized procedures and were analysed using ImageJ, an image-processing program. Each fish was described by 7 morphometric, 4 shape and 3 colour descriptors that were automatically measured by the soft- ware. The data resulted normally distributed and were submitted to one way-ANOVA that considered the production system (PS) as fixed effect. Linear discriminant analysis (LDA) was used as clas- sification method to identify sea bass PS. Any morphometric parameters (i.e., area, length) were different between PS, while solidity (0.93 vs 0.91, P<0.01), mean gray value (94.7 vs 76.0, P<0.001) and median gray value (89.9 vs 72.6, P<0.001) were higher in reared if compared to wild sea ...
Il trattamento del latte con ultrasuoni si è dimostrato efficace nel ridurre la presenza di diver... more Il trattamento del latte con ultrasuoni si è dimostrato efficace nel ridurre la presenza di diverse specie microbiche tipiche del latte crudo. In alcuni casi tale trattamento è capace di determinare la riduzione anche fino a 5 log della popolazione microbica. Invece, le informazioni disponibili in merito a un eventuale impatto di tale tecnologia sulle caratteristiche chimiche del latte sono poche. Scopo del lavoro è stato la valutazione dell’effetto degli ultrasuoni (8 combinazioni di tempo e ampiezza d’onda) sulla composizione chimica e i parametri di qualità del latte bovino. L’impiego degli ultrasuoni ha determinato una variazione significativa del profilo lattodinamografico. Si è osservato la diminuzione di k20 e r, l’aumento di a30 oltreché dell’acidità titolabile (°SH) e degli acidi grassi liberi. I primi risultati riguardanti la struttura della frazione caseinica non sembrano invece evidenziare alcun effetto. Tale tecnica sembrerebbe migliorare le caratteristiche di caseifica...
Among new technologies used to improve milk sanitization and shelf life, the treatment with ultra... more Among new technologies used to improve milk sanitization and shelf life, the treatment with ultrasounds showed positive effects on bacterial inactivation. The aim of this study was to evaluate the influence of different sonication parameters on E. coli inactivation and on milk sensory properties. An ultrasonic processor was used at different combinations of amplitude of ultrasonic wave (A: 70 vs. 100%), cycle (C: 0.5 vs. 1) and treatment time (T: 100 vs. 240 s) on UHT milk inoculated with E. coli (ATCC 11775) cells (105 CFU/ml). Before and after each treatment samples were plated in Plate Count Agar (PCA) and in Violet Red Bile Agar (VRB). All treatments were conducted in triplicate. To evaluate the effect of ultrasounds at different values of A (0-100%), C (0.5-1) and T (50-100s) on whole milk sensory properties, a triangle sensory test was carried out. Data were submitted to ANOVA according to a linear model. The increments of A, C and T, resulted in a higher E. coli inactivation ...
RIASSUNTO Nel settore lattiero-caseario sono state studiate tecnologie alternative ai trattamenti... more RIASSUNTO Nel settore lattiero-caseario sono state studiate tecnologie alternative ai trattamenti termici per garantire la salubrità del latte ed un prolungamento della sua shelf life. Tra le diverse tecnologie disponibili, la sonicazione, ovvero il trattamento con ultrasuoni, si è dimostrata efficace nei confronti di diversi microrganismi. In questo studio, si è valutata l’influenza di diversi parametri di sonicazione, quali durata, ampiezza dell’onda e livello di pulsazione, sulle caratteristiche sensoriali del latte e sull’abbattimento della carica microbica. Per il trattamento è stato utilizzato un sonicatore UP 400S (Hielscher USA, Inc., Ringwood, NJ). La sonicazione è stata effettuata in camera di flusso ed in batch. Si è trattato il latte crudo combinando diversi valori di ampiezza dell’onda (da 30 a 100%), pulsazione (0,5 e 1) e durata di sonicazione (da 0,5 a 8 s/ml). Per verificare l’eventuale effetto battericida degli ultrasuoni, è stata effettuata la determinazione della...
Introduction Among new technologies used to improve milk sanitization and shelf life, the treatme... more Introduction Among new technologies used to improve milk sanitization and shelf life, the treatment with ultrasounds (US) showed positive effects on bacterial inactivation, although it resulted responsible of some changes on milk sensory properties. The aim of this study was to evaluate the influence of different sonication parameters on volatile compounds production. Methods Ten combination of US wave amplitude (A: 70, 100%) and treatment duration (D: 0 (control), 50, 100, 200 and 300s) were applied to raw milk using a 400W ultrasonic processor, mounted with a 22 mm diameter horn. Solid-phase microextraction (SPME) was performed with a 100 µm Polydimethylsiloxane (PDMS) fibre and GC/MS analysis of volatile compounds adsorbed onto the SPME fibre was carried out taking into account spectra from M/Z 29 to M/Z 500. The experiment was replicated twice and three determinations were carried out per replicate. Data were subjected to analysis of variance using the software PAWS Statistic 18...
CyTA - Journal of Food, 2015
Two studies (storage and challenge tests) investigated the microbial shelf life combined with a s... more Two studies (storage and challenge tests) investigated the microbial shelf life combined with a semi-quantitative determination of volatile compounds of cloudy apple juices after power ultrasound (US) treatment. The sublethal injury of spoiler yeasts (Candida parapsilosis and Rhodotorula glutinis) was also evaluated. The maximum effect of sonication was observed 14 days post-treatment in both tests, especially on psychrotrophic count. Sublethal injury occurred only in C. parapsilosis. Microbiological data estimated the shelf life of sonicated juices to be around 21 days. The typical aroma compounds of the raw juices decreased quickly in control samples compared with sonicated ones. The flavor stability provided by US treatment seemed to be maintained for at least the first 14 days of cold storage. The US affected the shelf life of raw apple juices, probably due to yeast sublethal stress; some specific aroma compounds could be used as freshness or treatment markers.
Italian Journal of Food Safety, 2015
The aim of the study was to assess the in vitro effect of phenols extracted from oil vegetation w... more The aim of the study was to assess the in vitro effect of phenols extracted from oil vegetation water (PEOW) on several food-borne strains. Antibacterial activity of PEOW was based on the minimum bactericidal concentration (MBC) on microtitre assay. The taxa tested were: Staphylococcus (n. 5), Listeria (n. 4), Escherichia (n. 2), Salmonella (n. 1), Pseudomonas (n. 3), Lactobacillus (n. 2) and Pediococcus (n. 1). S. aureus and L. monocytogens showed the lowest level of resistance to PEOW (MBC=1.5-3 mg/mL). In contrast, the Gram negative strains (e.g. S. Typhimurium and Pseudomonas spp.) were in some cases unaffected by the tested doses and the MBCs ranged between 6 to 12 mg/mL. Starter cultures were dramatically reduced on growth (e.g. Staphylococcus xylosus; 0.75 mg/mL MBC). The thresholds for pathogenic strains could be considered for further applications of PEOW in food models (e.g. shelf life or challenge test studies).
Innovative Food Science & Emerging Technologies, 2015
ABSTRACT The aim of this study was to evaluate eight ultrasound (US) different combinations of am... more ABSTRACT The aim of this study was to evaluate eight ultrasound (US) different combinations of amplitude (70 and 100%) and duration (50, 100, 200 and 300 s) for their lethal capacity against Escherichia coli, Pseudomonas fluorescens, Staphylococcus aureus and Debaryomyces hansenii, the generation of volatile compounds (VC) and their impact on milk sensorial descriptors. The strongest treatment (100% × 300 s) led to a population reduction of 4.61, 2.75, 2.09 and 0.55 log for D. hansenii, P. fluorescens, E. coli and S. aureus, respectively, but caused milk sensorial deterioration. Four descriptors (metallic, burnt, rubbery and sharp) were correlated with treatment duration. Each of them, using stepwise regression analysis, was found to be associated with one VC (dodecanoic acid, R2 = 0.90; octanoic acid, R2 = 0.82; δ-dodecalactone, R2 = 0.81 and decanoic acid methyl ester, R2 = 0.78) that could be considered as a marker for milk sensorial deterioration caused by US.
Italian Journal of Food Safety, 2011
Italian Journal of Food Safety, 2014
Italian Journal of Food Safety, 2013
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Papers by Stefania Balzan