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1.
Foods ; 12(15)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37569242

RESUMO

Accurate species identification, especially in the fishery sector, is critical for ensuring food safety, consumer protection and to prevent economic losses. In this study, a total of 93 individual frozen-thawed cuttlefish samples from four different species (S. officinalis, S. bertheloti, S. aculeata, and Sepiella inermis) were collected from two wholesale fish plants in Chioggia, Italy. Species identification was carried out by inspection through morphological features using dichotomic keys and then through near-infrared spectroscopy (NIRS) measurements. The NIRS data were collected using a handled-portable spectrophotometer, and the spectral range scanned was from 900-1680 nm. The collected spectra were processed using principal component analysis for unsupervised analysis and a support vector machine for supervised analysis to evaluate the species identification capability. The results showed that NIRS classification had a high overall accuracy of 93% in identifying the cuttlefish species. This finding highlights the robustness and effectiveness of spectral analysis as a tool for species identification, even in complex spatial contexts. The findings emphasize the potential of NIRS as a valuable tool in the field of fishery product authentication, offering a rapid and eco-friendly approach to species identification in the post-processing stages.

2.
Ital J Food Saf ; 12(2): 11103, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37405147

RESUMO

The application of an electrochemical (impedance) tool for monitoring Escherichia coli contamination in shellfish was evaluated after 13 months of observation. The primary aim of the present study was to compare the standard most probable number (MPN) and µ-trac 4200 (log imped/100 g) for the assessment of E. coli contamination (log MPN/100 g) in non-depurated bivalve mollusks (BM) from five sampling areas of the Veneto-Emilian coast (Italy) (118 samples). The secondary aim was to evaluate the correlation between E. coli concentrations in BM and environmental factors on a large data set (690). The methods showed a moderate, positive correlation (0.60 and 0.69 Pearson and Spearman coefficients, respectively; P<0.01) in Ruditapes philippinarum. The McNemar test indicated analogous sample classification between methods, and the impedance method overestimated the most contaminated class (P=0.03; >4,600 MPN/100 g). The results highlighted the suitability of the impedance method for a faster evaluation and routine use especially in clams, while in Mytilus it seemed less effective. Different models built by multivariate permutational variance analysis and multinomial logistic regression selected the suitable environmental features able to predict the E. coli load. Overall, salinity and season affected the E. coli contamination, whereas locally it was mainly influenced by hydrometry and salinity. The application of the impedance method coupled with environmental data analysis could help purification phase management to adhere to legal limits and could represent an advantage for local control authorities to define actions, considering extreme meteorological events' effects as a proactive reaction to climate change.

3.
Ital J Food Saf ; 12(1): 11045, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-37064522

RESUMO

The genus Vibrio includes bacteria with different morphological and metabolic characteristics responsible for different human and animal diseases. An accurate identification is essential to assess the risks in regard to aquatic organisms and consequently to public health. The Multilocus Sequence Analysis (MLSA) scheme developed on the basis of 4 housekeeping genes (gyrB, pyrH, recA and atpA) was applied to identify 92 Vibrio strains isolated from crustaceans in 2011. Concatenated sequences were used for the phylogenetic and population analyses and the results were compared with those from biochemical identification tests. From the phylogenetic analysis, 10 clusters and 4 singletons emerged, whereas the population analysis highlighted 12 subpopulations that were well supported by phylogeny with few exceptions. The retrospective analysis allowed correct re-attribution of isolated species, indicating how, for some pathogens, there may be an overestimation of phenotypic identification (e.g. V. parahaemolyticus). Use of the PubMLST Vibrio database highlighted a possible genetic link between Sequence Type (ST) 529 and ST195 (V. alginolyticus) isolated from a human case in Norway during 2018. In addition to the identification of major risk groups of V. cholerae, V. vulnificus and V. parahaemolyticus, MLSA could be a valid support for species considered a minor risk, such as V. alginolyticus, V. mimicus and V. fluvialis. Due to the increased incidence of vibriosis in Europe, the application of different tools will also have to be considered to investigate the possible epidemiological links of the various species in the perspective of Open Science to protect the consumer.

4.
J Microbiol Biol Educ ; 23(1)2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35496709

RESUMO

"WeSocial: Online Learning Community" is a project aiming to provide students with the basic skills in science communication via social media as a useful tool in their future careers and to disseminate the University Department of Comparative Biomedicine and Food Science activities to the general public. The project is based on two main actions: professional training on science communication and social media strategies, and the establishment of an editorial team composed of students supervised by the teaching staff. When the training phase was concluded, official department accounts on Instagram (bca_campus_unipd) and Facebook (BCA_campus_unipd) were opened. Currently, the students' editorial team (SET) oversees publishing a maximum of 3 posts per week, whose content deals with the academic, research, and educational areas of the department seen through the students' eyes. The social media accounts are constantly growing and becoming a "place" for the virtual community of the department. Since students are both "information producers" and the "audience" of the project, they propose and focus on issues particularly important to them. As a result, the department's social media has become a meaningful and relevant experience for students, enhancing their sense of belonging to the departmental and university community life. Moreover, the project is fostering the interaction between students and teaching staff and, thanks to peer communication, is increasing the awareness of department activities especially in the student audience.

5.
Front Vet Sci ; 9: 889612, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35619608

RESUMO

Clay minerals are naturally occurring rock and soil materials primarily composed of fine-grained aluminosilicate minerals, characterized by high hygroscopicity. In animal production, clays are often mixed with feed and, due to their high binding capacity towards organic molecules, used to limit animal absorption of feed contaminants, such as mycotoxins and other toxicants. Binding capacity of clays is not specific and these minerals can form complexes with different compounds, such as nutrients and pharmaceuticals, thus possibly affecting the intestinal absorption of important substances. Indeed, clays cannot be considered a completely inert feed additive, as they can interfere with gastro-intestinal (GI) metabolism, with possible consequences on animal physiology. Moreover, clays may contain impurities, constituted of inorganic micronutrients and/or toxic trace elements, and their ingestion can affect animal health. Furthermore, clays may also have effects on the GI mucosa, possibly modifying nutrient digestibility and animal microbiome. Finally, clays may directly interact with GI cells and, depending on their mineral grain size, shape, superficial charge and hydrophilicity, can elicit an inflammatory response. As in the near future due to climate change the presence of mycotoxins in feedstuffs will probably become a major problem, the use of clays in feedstuff, given their physico-chemical properties, low cost, apparent low toxicity and eco-compatibility, is expected to increase. The present review focuses on the characteristics and properties of clays as feed additives, evidencing pros and cons. Aims of future studies are suggested, evidencing that, in particular, possible interferences of these minerals with animal microbiome, nutrient absorption and drug delivery should be assessed. Finally, the fate of clay particles during their transit within the GI system and their long-term administration/accumulation should be clarified.

6.
Antioxidants (Basel) ; 10(12)2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34943072

RESUMO

This study aims at evaluating the effect of a phenol-rich extract obtained from the concentration and purification of olive mill wastewaters (added at a ratio of 87.5 and 175 mg of phenols/kg meat) on the stability and sensory quality of beef hamburgers packed under modified atmosphere and stored under alternating exposure to fluorescent light at 4 ± 2 °C for 9 days. The hamburgers were sampled at different times (0, 6, and 9 days) and grilled at 200 °C. After 9 days, more than 56% of the added phenols in the raw burgers and more than 20% the grilled ones were retained. The results show that both concentrations of phenolic extract proved to effectively reduce primary and secondary lipid oxidation, as well as cholesterol oxidation products (COPs), during the shelf-life of raw hamburgers. Peroxide value, thiobarbituric acid reactive substances, and total COPs were up to 1.4-, 4.5-, and 8.8-fold lower in phenol-enriched raw hamburgers, respectively, than in the control samples; a similar trend was noted also in phenol-enriched cooked hamburgers (1.3-, 5.7-, and 4-fold lower). The sensory analysis also confirmed the effectiveness of the addition of phenolic extract, resulting in a positive effect on the red color intensity (raw product) and thus reducing browning during storage.

7.
Foods ; 10(8)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34441458

RESUMO

An appropriate seafood origin identification is essential for labelling regulation but also economic and ecological issues. Near infrared (NIRS) reflectance spectroscopy was employed to assess the origins of cuttlefish caught from five fishing FAO areas (Adriatic Sea, northeastern and eastern central Atlantic Oceans, and eastern Indian and western central Pacific Oceans). A total of 727 cuttlefishes of the family Sepiidae (Sepia officinalis and Sepiella inermis) were collected with a portable spectrophotometer (902-1680 nm) in a wholesale fish plant. NIR spectra were treated with standard normal variate, detrending, smoothing, and second derivative before performing chemometric approaches. The random forest feature selection procedure was executed to select the most significative wavelengths. The geographical origin classification models were constructed on the most informative bands, applying support vector machine (SVM) and K nearest neighbors algorithms (KNN). The SVM showed the best performance of geographical classification through the hold-out validation according to the overall accuracy (0.92), balanced accuracy (from 0.83 to 1.00), sensitivity (from 0.67 to 1.00), and specificity (from 0.88 to 1.00). Thus, being one of the first studies on cuttlefish traceability using NIRS, the results suggest that this represents a rapid, green, and non-destructive method to support on-site, practical inspection to authenticate geographical origin and to contrast fraudulent activities of cuttlefish mislabeled as local.

8.
Molecules ; 26(14)2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34299582

RESUMO

Olive vegetation water (OVW) is a by-product with a noticeable environmental impact; however, its polyphenols may be reused food and feed manufacture as high-value ingredients with antioxidant/antimicrobial activities. The effect of dietary supplementation with OVW polyphenols on the gut microbiota, carcass and breast quality, shelf life, and lipid oxidation in broiler chickens has been studied. Chicks were fed diets supplemented with crude phenolic concentrate (CPC) obtained from OVW (220 and 440 mg/kg phenols equivalent) until reaching commercial size. Cloacal microbial community (rRNA16S sequencing) was monitored during the growth period. Breasts were submitted to culture-dependent and -independent microbiological analyses during their shelf-life. Composition, fatty acid concentration, and lipid oxidation of raw and cooked thawed breasts were measured. Growth performance and gut microbiota were only slightly affected by the dietary treatments, while animal age influenced the cloacal microbiota. The supplementation was found to reduce the shelf life of breasts due to the growth of spoilers. Chemical composition and lipid oxidation were not affected. The hydroxytyrosol (HT) concentration varied from 178.6 to 292.4 ug/kg in breast muscle at the beginning of the shelf-life period. The identification of HT in meat demonstrates that the absorption and metabolism of these compounds was occurring efficiently in the chickens.


Assuntos
Galinhas , Conservação de Alimentos , Microbioma Gastrointestinal/efeitos dos fármacos , Carne , Olea/química , Polifenóis , Água , Animais , Galinhas/crescimento & desenvolvimento , Galinhas/microbiologia , Polifenóis/química , Polifenóis/farmacologia , Água/química , Água/farmacologia
9.
Int J Food Microbiol ; 334: 108806, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-32805512

RESUMO

Due to its chemical properties, honey does not foster the growth of microorganisms, however it may contain a rich microbial community, including viable, stressed, and not viable microbes. In order to characterize honey microbiota focusing on the difference between products from beekeepers and large retail in the present study a culture-independent approach based on DNA metabarcoding was applied. Honey samples were collected from Local Beekeepers (LB) and Market sales (M) during four years with the aim to investigate the microbiological quality in the honey market. Extraction and amplification of DNA from honey samples showed reduced efficiency with increasing age of honey, with the loss of 50-80% of samples four years old (2014). For this reason, only samples of similar age were compared and the analysis of microbial communities focused on year 2017, for a total of 75 samples. Differences in alpha and beta-diversity were evidenced comparing microbial communities between LB and M samples. In particular, contaminant bacteria dominated the microbiota in M samples while LB samples were enriched in Lactic Acid Bacteria (LAB) that cannot be isolated with culture-dependent approaches.


Assuntos
Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Mel/microbiologia , Microbiota , Bactérias/classificação , Bactérias/genética , Código de Barras de DNA Taxonômico , DNA Bacteriano/genética , DNA Fúngico/genética , Microbiologia de Alimentos , Fungos/classificação , Fungos/genética , Itália , Lactobacillales/classificação , Lactobacillales/genética , Lactobacillales/isolamento & purificação , Microbiota/genética
10.
Food Sci Nutr ; 8(5): 2299-2306, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32405387

RESUMO

Honeybush (Cyclopia subternata Vogel) is an indigenous South African shrub enjoyed as hot brewed tea. "Unfermented" honeybush is also a potential antioxidant bioactive extract for foodstuffs due to its polyphenol content. The effect of "unfermented" honeybush extract (Hob; 0.5%) was evaluated in typical Italian salami and compared with nitrate (Nit; 100 mg/kg) and a control (Ctl; without nitrate or honeybush). After 35 days of ripening, Hob had a higher (p < .01) water activity (0.928), compared with Ctl (0.923) and Nit (0.924). Final pH (5.35-5.24) was not affected by treatments. Lower lipid oxidation was observed in Hob and Nit treatments (p < .001) compared with Ctl. Internal color and odor intensity were similar among treatments. Salami with honeybush extract had less spontaneous outer surface mold growth whereas the Ctl showed intermediate growth (p < .05). Honeybush extract seems a promising natural ingredient with antioxidant action.

11.
J Food Sci Technol ; 56(10): 4437-4447, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31686675

RESUMO

Few works to date have reported the application of near-infrared spectroscopy (NIRS) for the characterization and authentication of cephalopods. This study investigated the feasibility of a portable NIRS instrument for the non-destructive freshness evaluation of fresh (F) and frozen-thawed (FT) cuttlefish (Sepia officinalis). Samples were examined by chemical, microbiological and sensorial analyses, during 13 days of conservation at 3 °C. The spectral data were collected on lateral mantle of cuttlefish, and different partial least squares discriminant analyses (PLS-DA) were applied for classification purposes. The interpretation of spectra was also investigated by applying the specific water coordinates, using aquaphotomics. Few significant differences in the wet chemistry and microbiological data were detected between F and FT during storage. The quality index method and microbiological analyses suggested similar behavior between F and FT samples until to near 9 days of shelf life. PLS-DA models with the spectral range 900-1650 nm achieved a classification precision of 0.91 between F and FT, while the performances for the prediction of storage days were less effective. The results of aquaphotomics plotted in aquagrams were suitable for the interpretation of the main physicochemical changes of cuttlefish throughout the shelf life. The water coordinates suggested a different molecular conformation of water species in the FT than F samples, with more free water molecules and a lower amount of bound species and the water solvation shell, respectively.

12.
Food Microbiol ; 76: 296-303, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166154

RESUMO

Edible insects are increasing in popularity as a trendy new food item in many countries worldwide. However, little information is available regarding the associated foodborne pathogens, in particular, the spore-forming bacteria that may be present in these processed foods. In this study, mealworms, crickets, mole crickets and silkworms that are widely available online were investigated for microbial quality traits. Whereas water activity and pH results revealed a stable product, microbiota characterisation highlighted wide variability among the analysed insect species. Among the microbial targets considered in this study, total viable count, total aerobic spores and Bacillus cereus count were the most suitable for describing the food safety and microbial quality of these products. Endospore-forming bacteria ascribed to the B. cereus group were identified with genetic methods and putative virulence patterns. Three major clusters were delineated according to the phylogenetic analysis of the B. cereus group: B. cereus, B. thuringiensis and B. cytotoxicus, with virulence patterns particular to the enterotoxin genes found in each cluster. This work represents a first step in the hazard identification of B. cereus group bacteria isolated from edible insects. The presented results should also be considered with respect to domestic handling and rehydration of such products prior to consumption.


Assuntos
Bacillus/isolamento & purificação , Dieta , Inocuidade dos Alimentos , Insetos/microbiologia , Animais , Bacillus/genética , Bacillus cereus/isolamento & purificação , Contagem de Colônia Microbiana/métodos , Qualidade de Produtos para o Consumidor , Enterotoxinas/genética , Microbiologia de Alimentos/métodos , Humanos , Filogenia , Esporos Bacterianos/genética , Esporos Bacterianos/isolamento & purificação , Virulência
13.
Ital J Food Saf ; 7(1): 6928, 2018 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-29732328

RESUMO

Near infrared spectroscopy (NIRs) and ultraviolet visible spectroscopy (UV-vis) have been investigated as rapid techniques to characterize foodborne bacteria through the analysis of the spectra of whole cells or microbial suspensions. The use of spectra collected from broth cultures could be used as a fingerprint for strain classification using a combined polyphasic approach. The aim of this study was to evaluate the feasibility of NIRs and UV-vis for the characterization of blue strains belonging to the Pseudomonas fluorescens group. The bacteria were isolated from different food matrices, including some spoiled samples (blue discoloration). Eightyone strains previously identified at the species level were grown in Minimal Bacterial Medium broth under standard conditions at 22°C. Two biological replicates were centrifuged in order to separate the bacterial cells from the extracellular products. Six aliquots per strain were analyzed on a small ring cup in transflectance mode (680-2500 nm, gap 2 nm). A subset of 39 strains was evaluated by UV-vis to determine changes in the spectral characteristics at 48 and 72 hours. Several chemometric approaches were tested to assess the performance of NIRs and UVvis. According to the variable importance in projection (VIP), the 1892-2020 nm spectral region showed the highest level of discrimination between blue strains and others. Additional information was provided in the 680-886 and 1454-1768 nm regions (aromatic C-H bonds) and in the 2036-2134 nm region (fatty acids). Changes in UV-vis spectral data (at 48 and 72 hours) appear to indicate the presence of phenazine and catecholic compounds in extracellular products.

14.
Ital J Food Saf ; 7(1): 6967, 2018 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-29732331

RESUMO

Processing of alpine milk in malga farms is carried out under conditions that can favor contamination by coliforms, coagulase-positive staphylococci, or pathogens such as Listeria monocytogenes. With the aim to improve the hygienic characteristics and safety of cheese produced in four malga farms the use of lyophilized Natural Milk Culture prepared with selected strains was tested.. Two cheesemaking tests were carried out in the same day always starting from the same milk: in the first case following the malga recipe that uses either Natural Whey Culture or without the addition of a starter, in the second one using a Natural Milk Culture. Cheesemaking were carried out in four malga farms located in the west area of Trentino region within the same week. For hygienic and safety evaluation, aerobic colony count, coagulase-positive staphylococci, Escherichia coli, staphylococcal toxins, Listeria monocytogenes, and Salmonella spp, pH and aw were determined in raw milk from evening and morning milking, curd in vat, curd after extraction and two months-ripened cheese. Pathogens or toxins, high values of coagulase- positive staphylococci and E. coli were not found in cheese samples. However, in the curd coagulase-positive staphylococci reached values almost of 5 Log CFU/g in the two malga without starter cultures. The use of Natural Milk Culture reduced E. coli counts. In addition, DNA was extracted from cheese samples and from Natural Milk Culture and the composition of the microbial community determined by Next Generation Sequencing method. The determination of cheese microbial communities demonstrated that the use of Natural Milk Culture exerted different effects in the different malga, in any case preserving bacterial biodiversity.

15.
Foodborne Pathog Dis ; 14(8): 454-464, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28514180

RESUMO

BACKGROUND: Vibrio parahaemolyticus is an emerging foodborne pathogen in the Mediterranean, usually associated with shellfish consumption. The increase in the number of outbreaks in Europe is primarily associated with the global warming of the ocean that has a great impact on the spread and genetic selection of waterborne pathogens. The primary role of Italy in Europe's mollusk production, together with the fact that cases of infections with V. parahaemolyticus are not always notified to the European community, highlighted the necessity of acquiring new information about the epidemiological involvement of shellfish products. OBJECTIVE: The aim of the study was to provide useful insights into the first steps of the Risk Assessment associated with V. parahaemolyticus through the molecular characterization of isolates from commercialized mollusks. MATERIALS AND METHODS: A total of 102 strains identified as V. parahaemolyticus were investigated as part of a larger sampling (1-year survey) from several shellfish species collected from the Venice lagoon and the North Adriatic sea. All strains were characterized by multilocus sequence typing and tested for the presence of virulence genes (trh and tdh). The study of sampling/environmental factors and epidemiological analyses was performed to describe the behaviors of the different genetic populations. RESULTS: The population structure analysis highlighted three genetic clusters that could be subject to temperature selection during cold (≤15°C) and warm (>16°C) seasons. Moreover, other factors, such as molluscan species (clams/mussels), probably played a role in the distribution of genetic clusters. Although few strains carried the virulence factors (n = 6 trh+), epidemiological links with clinical isolates and a local dissemination of some sequence types were underlined. CONCLUSION: This work provides a useful background on the genotype spread as a first step in the Hazard Identification in light of future climate changes.


Assuntos
Bivalves/microbiologia , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Frutos do Mar , Vibrioses/microbiologia , Vibrio parahaemolyticus/classificação , Animais , Técnicas de Tipagem Bacteriana , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Itália , Tipagem de Sequências Multilocus , Filogenia , Saúde Pública , Estações do Ano , Vibrioses/epidemiologia , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/isolamento & purificação , Virulência , Fatores de Virulência
16.
Ital J Food Saf ; 6(1): 6183, 2017 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-28462202

RESUMO

Food packaging frequently reports the terms natural, 100% natural or similar. Often these indications induce consumers to purchase those products that are considered healthier and fresher. The overall goal of this study was to assess what teen consumers perceive to be genuine and natural foods. A questionnaire was distributed to the students of some high schools (lyceum, technical and professional institutes). It was completed by 349 females and 314 males, with an average age of 17.6 years. Respondents are quite interested in the information on recipes, diet, beauty and food safety; websites were important information retrieval tools. Genuine food is defined mainly as fruits and vegetables, home-made and salubrious, with less or without fat and that is good for health. Meanwhile, natural is demarcated primarily by the absence of additives and manipulation or treatments (negative impact). Also fruits and vegetables and organic production are associated to natural. The existence of a natural food preference is well described and the presence on food label may cause a wrong perception of healthfulness.

17.
Ital J Food Saf ; 6(1): 6184, 2017 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-28462203

RESUMO

Challenge tests are a clear opportunity for manufacturers interested in the evaluation of their management system with the aim to reduce the spread of foodborne pathogens. This is a main concern especially in ready-to-eat food in relation to the risk associated with Listeria monocytogenes. For small and medium-scale food industry the manufacturing practices and products formulation are characterised by a wider variability and poor repeatability. The use of ad hoc challenge test and the comparison among different processing systems are strongly required. This paper reports a preliminary comparison among different challenge tests (n=12) commissioned by three manufacturers of raw-fermented salami during a period of three years (2013-2016). The challenge tests were designed to evaluate the growth potential (δ) of L. monocytogenes during the whole processing period of the salami. The doughs were prepared according to different formulations: the simplest formulation was represented by the use of salt, potassium nitrate, black pepper and starter cultures, while the most composited formulations also included the use of sugars and ascorbic acid in addition to nitrite salt. All the processing steps were conducted within an experimental laboratory dedicated for the processing of meat. After stuffing, the salami were dried and ripened under temperature and relative humidity control. The sugar inclusion can be considered as a protective factor, while the drying step at high temperature (above 20°C) was associated with higher δ values (δ>0.5 log10 cfu/g). The addition of starter cultures, and the subsequent acidification highlighted the importance of pH as the parameter able to affect the L. monocytogenes growth.

18.
Ital J Food Saf ; 5(2): 5651, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27800444

RESUMO

Phenols are plant metabolites characterised by several interesting bioactive properties such as antioxidant and bactericidal activities. In this study the application of a phenols concentrate (PC) from olive vegetation water to two different fresh products - gilt-head seabream (Sparus aurata) and chicken breast - was described. Products were treated in a bath of PC (22 g/L; chicken breast) or sprayed with two different solutions (L1:0.75 and L2:1.5 mg/mL; seabream) and then stored under refrigeration conditions. The shelf life was monitored through microbiological analyses - quality index method for seabream and a specific sensory index for raw breast. The secondary products of lipid-peroxidation of the chicken breast were determined using the thiobarbituric acid reactive substances (TBARs) test on cooked samples. Multivariate statistical techniques were adopted to investigate the impact of phenols and microbiological data were fitted by DMfit software. In seabream, the levels of PC did not highlight any significant difference on microbiological and sensory features. DMfit models suggested an effect only on H2S producing bacteria with an increased lag phase compared to the control samples (C: 87 h vs L2: 136 h). The results on chicken breast showed that the PC bath clearly modified the growth of Pseudomonas and Enterobacteriaceae. The phenol dipping was effective in limiting lipid-peroxidation (TBARs) after cooking. Treated samples disclosed an increase of shelf life of 2 days. These could be considered as preliminary findings suggesting the use of this concentrate as preservative in some fresh products.

19.
Front Microbiol ; 7: 1272, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27582735

RESUMO

In the past, milk whey was only a by-product of cheese production, but currently, it has a high commercial value for use in the food industries. However, the regulation of whey management (i.e., storage and hygienic properties) has not been updated, and as a consequence, its microbiological quality is very challenging for food safety. The Next Generation Sequencing (NGS) technique was applied to several whey samples used for Ricotta production to evaluate the microbial community composition in depth using both RNA and DNA as templates for NGS library construction. Whey samples demonstrating a high microbial and aerobic spore load contained mostly Firmicutes; although variable, some samples contained a relevant amount of Gammaproteobacteria. Several lots of whey acquired as raw material for Ricotta production presented defective organoleptic properties. To define the volatile compounds in normal and defective whey samples, a headspace gas chromatography/mass spectrometry (GC/MS) analysis was conducted. The statistical analysis demonstrated that different microbial communities resulted from DNA or cDNA library sequencing, and distinguishable microbiota composed the communities contained in the organoleptic-defective whey samples.

20.
Int J Food Microbiol ; 228: 34-43, 2016 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-27088870

RESUMO

The use of phenolic compounds derived from agricultural by-products could be considered as an eco-friendly strategy for food preservation. In this study a purified phenol extract from olive vegetation water (PEOVW) was explored as a potential bioactive ingredient for meat products using Italian fresh sausage as food model. The research was developed in two steps: first, an in vitro delineation of the extract antimicrobial activities was performed, then, the PEOVW was tested in the food model to investigate the possible application in food manufacturing. The in vitro tests showed that PEOVW clearly inhibits the growth of food-borne pathogens such as Listeria monocytogenes and Staphylococcus aureus. The major part of Gram-positive strains was inhibited at the low concentrations (0.375-3mg/mL). In the production of raw sausages, two concentrates of PEOVW (L1: 0.075% and L2: 0.15%) were used taking into account both organoleptic traits and the bactericidal effects. A multivariate statistical approach allowed the definition of the microbial and physicochemical changes of sausages during the shelf life (14days). In general, the inclusion of the L2 concentration reduced the growth of several microbial targets, especially Staphylococcus spp. and LABs (2log10CFU/g reduction), while the increasing the growth of yeasts was observed. The reduction of microbial growth could be involved in the reduced lipolysis of raw sausages supplemented with PEOVW as highlighted by the lower amount of diacylglycerols. Moisture and aw had a significant effect on the variability of microbiological features, while food matrix (the sausages' environment) can mask the effects of PEOVW on other targets (e.g. Pseudomonas). Moreover, the molecular identification of the main representative taxa collected during the experimentation allowed the evaluation of the effects of phenols on the selection of bacteria. Genetic data suggested a possible strain selection based on storage time and the addition of phenol compounds especially on LABs and Staphylococcus spp. The modulation effects on lipolysis and the reduction of several microbial targets in a naturally contaminated product indicates that PEOVW may be useful as an ingredient in fresh sausages for improving food safety and quality.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Produtos da Carne/microbiologia , Olea/química , Fenóis/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Água/química , Animais , Contagem de Colônia Microbiana , Itália , Listeria monocytogenes/crescimento & desenvolvimento , Produtos da Carne/análise , Extratos Vegetais/farmacologia , Staphylococcus aureus/fisiologia , Suínos
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