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61.
Josep Rubert Kamila Hurkova Milena Stranska Jana Hajslova 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(4):605-613
Tiger nuts and tiger nut milk are well-known Valencian products, and step-by-step these tubers and the tuber-based beverage are becoming more and more relevant products in international markets. However, the increasing demand and success of Valencian tiger nuts did not allow protected designation of origin (PDO) tuber to supply the domestic and international markets. Therefore, the verification of the geographical origin is highly required. In this research, the main objective was to combine an advance analytical method and chemometrics tools in order to decipher the geographical origin of 45 tiger nut samples from (i) ‘Xufa de València’ PDO and (ii) African samples. The analytical method, based on solid-liquid extraction followed by ultra-high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-HRMS) metabolomics approach, highlighted sensitivity and wide linear dynamic range in order to simultaneously analyse polar and non-polar metabolites. After data processing, a pronounced sample clustering according to the geographical origin was clearly observed using unsupervised models, and supervised models revealed that tiger nuts lipidome was associated with the geographical origin. As a result, African samples highlighted an overexpression of phospholipids, such as phosphatidylethanolamine 34:1, and triacylgricerols crosslinked to environmental stress and alteration of membrane lipid compositions. 相似文献
62.
Daniela Campaniello Antonio Bevilacqua Barbara Speranza Milena Sinigaglia Maria Rosaria Corbo 《Food and Bioprocess Technology》2018,11(6):1139-1148
The topic of this paper is the investigation of the antibacterial effect of ultrasound (US) towards Salmonella enterica in a rice beverage. The beverage was inoculated at different levels (8 and 5 log CFU/mL) and US-treated; then, a challenge test under refrigeration was carried out. The maximum net power of the equipment was 130 W; the treatment was carried out at 40–100% of the net power, for 2–10 min; the pulse was set to 2–10 s. For both the inoculum levels, power and time were the most important factors for the antimicrobial effect towards S. enterica. The combinations resulting in the highest inactivation of the pathogen were tested during the challenge test at 4 °C, and in some combinations, S. enterica remained below the detection limit for 13 days. 相似文献
63.
Antonio Bevilacqua Leonardo Petruzzi Barbara Speranza Daniela Campaniello Milena Sinigaglia Maria Rosaria Corbo 《International Journal of Food Science & Technology》2018,53(5):1262-1268
The main topic of this study was to study how cell surface hydrophobicity (CSH) could change in response to pH, temperature and inulin; Lactobacillus acidophilus La‐5 was used as a model microorganism. pH, temperature, inulin and incubation time (exposure to prebiotic or incubation at pH 4.0 and 9.0) were combined through a full factorial design and a Central Composite Design; the results were analysed using a multifactorial anova (first step) and a stepwise regression (second step). Temperature and pH significantly affected CSH: an increase in the temperature determined a significant increase in CSH, whereas the correlation pH vs. CSH was negative, as an increase in pH caused a significant decrease in CSH. Inulin played a significant role, but its effect could be influenced by temperature, pH and exposure time. This study is the first approach on the effects of some environmental factors on CSH and suggests that the culturing conditions and/or the exposure to some prebiotics could modify it with positive or negative effects. 相似文献
64.
65.
Marilù Decimo Stefano Morandi Tiziana Silvetti Milena Brasca 《Journal of food science》2014,79(10):M2081-M2090
Eighty psychrotrophic bacterial strains, isolated from different northwest Italian bulk tank milks destined for Grana Padano cheese production, were identified by 16S rRNA gene amplification and partial sequence analysis of the rpoB gene. Pseudomonas spp. were the most commonly occurring contaminants, P. fluorescens being the predominant isolated species, along with Enterobacteriaceae, primarily Serratia marcescens. RAPD‐PCR was used to study genetic variability and distinguish closely related strains; a high degree of genetic heterogeneity among the strains was highlighted. All the strains were characterized for their ability to produce proteases, lipases and lecithinases at different temperatures (7, 22, and 30 °C). Forty‐one of the psychrotrophic strains were positive for all the enzymatic activities. The highest number of positive strains for all the incubation temperatures was found for lipolytic activity (59), followed by proteolytic (31) and lecithinase (28) activities, and the enzymatic traits varied among the Pseudomonas and Enterobacteriaceae strains. The proteolytic psychrotrophic strains were screened for the presence of the aprX gene, coding for a heat‐resistant metalloprotease in Pseudomonas spp. The aprX gene was detected in 19 of 63 Pseudomonas strains, and was widespread in the P. fluorescens strains (14/19). 相似文献
66.
Lucilla Iacumin Francesca Cecchini Marisa Manzano Milena Osualdini Daria Boscolo Sandi Orlic Giuseppe Comi 《Food microbiology》2009
Four types of sourdoughs (L, C, B, Q) from artisanal bakeries in Northern Italy were studied using culture-dependent and culture-independent methods. In all samples, the yeast numbers ranged from 160 to 107 cfu/g, and the numbers of lactic acid bacteria (LAB) ranged from 103 to 109 cfu/g. The isolated LAB were sequenced, and a similarity was noted between two samples (C, Q), both in terms of the species that were present and in terms of the percentage of isolates. In these two samples, Lactobacillus plantarum accounted for 73% and 89% of the bacteria, and Lactobacillus brevis represented 27% and 11%. In the third sample (B), however, the dominant LAB isolate was Lb. brevis (73%), while Lb. plantarum accounted for only 27%. The fourth sourdough (L) was completely different from the others. In this sample, the most prominent isolate was Weisella cibaria (56%), followed by Lb. plantarum (36%) and Pediococcus pentosaceus (8%). In three out of four samples (L, C and Q), all of the yeasts isolated were identified as Saccharomyces cerevisiae, yet only Candida humilis (90%) and Candida milleri (10%) were isolated in the fourth sample (B). The microbial ecology of the sourdoughs was also examined with direct methods. The results obtained by culture-independent methods and DGGE analysis underline a partial correspondence between the DNA and RNA analysis. These results demonstrate the importance of using a combined analytical approach to explore the microbial communities of sourdoughs. 相似文献
67.
The effect of a negatively charged polymer, κ-carrageenan, on the aggregation behaviour of whey proteins during heating was studied. Aqueous solutions of whey protein isolate (WPI) at 0.5% were heated in the presence of κ-carrageenan (0.1%) at pH 7.0. This concentration was chosen as optimal in the detection of the intermediate aggregates during chromatographic analysis. The residual unaggregated protein, the intermediate aggregates and the soluble aggregates were all examined as a function of heating time and temperature, using size-exclusion chromatography coupled with light scattering detection. The presence of κ-carrageenan did not affect the aggregation of whey proteins heated at 75 °C; however, a change in the mechanism of aggregation seemed to occur at higher temperatures, and intermediates with higher molecular mass formed at 85 °C. At 90 °C, in the presence of κ-carrageenan, the extent of WPI aggregation was much larger, as soluble aggregates were no longer present and less residual protein was recovered in the unaggregated peak. 相似文献
68.
The effect of the addition of flaxseed gum on the physicochemical properties of whey protein-stabilized (WPI) oil-in-water emulsions at pH 3.5 was investigated. Two different varieties (Emerson and McDuff) were tested at concentrations ranging from 0% to 0.33% (w/v), by measuring droplet size, ζ-potential, phase separation behavior, microstructure and apparent viscosity. With addition of flaxseed gum the ζ-potential of the droplets decreased from around +30 mV to a negative value (−10 mV) at concentrations >0.2%. These results indicated that the negatively charged polysaccharide fraction from flaxseed interacted with the protein adsorbed at the interface. An increase in apparent particle size was also noted with increasing flaxseed concentration, with destabilization becoming visually evident at concentrations higher than 0.1% (w/v). Microscopy, rheological data and size distribution analysis demonstrated for the first time that flaxseed gum interacts with protein-stabilized oil droplets at low pH, causing bridging flocculation. No significant differences were noted between flaxseed gums extracted from the Emerson and McDuff varieties. This research demonstrated that the electrostatic interactions between flaxseed gums and protein-stabilized emulsions need to be controlled when designing novel acidic beverages containing these polysaccharides. 相似文献
69.
Nonthermal Technologies for Fruit and Vegetable Juices and Beverages: Overview and Advances 下载免费PDF全文
Antonio Bevilacqua Leonardo Petruzzi Marianne Perricone Barbara Speranza Daniela Campaniello Milena Sinigaglia Maria Rosaria Corbo 《Comprehensive Reviews in Food Science and Food Safety》2018,17(1):2-62
In recent years, there has been a growing interest in the design of novel nonthermal processing systems that minimally modify sensory, nutritional, and functional properties of fruit and vegetable juices and beverages. The benefits of nonthermal treatments are strongly dependent on the food matrix. Thus, an understanding of the effects that these technologies exert on the properties of juices and beverages is important to design and optimize technological parameters to produce value‐added products. This review covers research on nonthermal electrical treatments, high pressure processing, ultrasound, radiation processing, inert gas treatments, cold plasma, and membrane processing. Advances towards optimization of processing conditions, and combined technologies approaches have been also extensively reviewed. This information could be useful to: (1) manage processing systems and optimize resources; (2) preserve nutritional value and organoleptic properties, and (3) provide processing conditions for validation of these technologies at the industrial scale. 相似文献
70.
The Different Physical and Chemical Composition of Grape Juice and Marc Influence Saccharomyces cerevisiae Strains Distribution During Fermentation 下载免费PDF全文