58 research outputs found

    Microbiological quality of filled pasta in relation to the nature of heat treatment.

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    The microbial population present in 49 samples of Italian industrially processed filled pasta was characterized and its changes during refrigerated storage were evaluated. The most frequently isolated species belonged to the genus Bacillus. No pathogenic organisms were isolated from the processed industrial pasta. As a consequence of the diversity of composition and thermal treatment a wide variability was observed (from less than 3 days to more than 1 month) in the shelf life at 4 degrees C of the industrial "fresh filled pasta." However, the results obtained suggested that the shelf life of the processed products depend not only on the number of surviving cells but also on the textural or microstructural changes induced by the heat treatment. Challenge tests using Staphylococcus aureus showed that even pasteurization values (P 70(10), expressed as an equivalent process time, in minutes, necessary to obtain at 70 degrees C the same lethal effect as during the actual process) not exceeding 2 were able to remarkably reduce the cell load of this organism. Subsequent growth of the surviving S. aureus cells occurred only at temperatures > 7 degrees C, particularly when the water activity (aw) values were higher than 0.97

    Volatile compounds produced in wine by Colombian wildSaccharomyces cerevisiae strains

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    Some tropicalSaccharomyces cerevisiae strains, isolated fromChampus, a traditional Colombian low alcoholic fermented beverage, were characterised in order to select yeasts for aroma improvement in wine. H2S production, volatile acidity, β-glucosidase activity, higher alcoholesters and terpenes production were evaluated in this study. These tropical strains were characterised by a considerable production of ethyl hexanoate, 2-phenylethanol, 2-phenylethyl acetate, and geraniol, detected by SPME-GC-MS. Odor activity values were calculated to analyse the effects of yeasts strains on wine aroma, resulting in six distinctive wine groups, as evidenced by discriminant analysis. These results suggest thatSaccharomyces strains isolated fromChampus can be an important source for new tropical yeast biotypes with potential winemaking applications, producing a wide range of aroma compounds

    A survey of Saccharomyces populations associated with wine fermentations from the Apulia region (South Italy)

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    The aim of this paper was to investigate the genetic and phenotypic characteristics of yeasts isolated from samples of grape musts collected from four different areas of Apulia region. The 68 yeast isolates were identified asSaccharomyces cerevisiae by PCR-RFLP of 5.8S-ITS region of the rRNA gene. Individual isolates were differentiated by RAPD-PCR and AFLP. The following oenological traits were studied: fermentation power, resistance to cycloheximide, alcohol and SO2, formation of SO2 and H2S, β-glucosidase activity, and production of biogenic amines and secondary compounds. Many phenotypes were common to several yeasts isolated from the four different areas, such as high SO2 resistance and fermentation power. In addition, someS. cerevisiae isolates showed a β-glucosidase activity and others had a high resistance to cycloheximide. All the strains formed biogenic amines. Solid Phase Microextraction was used to determine secondary compounds produced in wine by the single yeast cultures

    Chitosan Coating Enriched With Ruta graveolens L. Essential Oil Reduces Postharvest Anthracnose of Papaya

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    Anthracnose of papaya (Carica papaya L.) caused by the fungus Colletotrichum spp. is one of the most economically important postharvest diseases. Coating with chitosan (CS) and Ruta graveolens essential oil (REO) might represent a novel eco-friendly method to prevent postharvest anthracnose infection. These compounds show both antimicrobial and eliciting activities, although the molecular mechanisms in papaya have not been investigated to date. In this study, the effectiveness of CS and REO alone and combined (CS-REO) on postharvest anthracnose of papaya fruit during storage were investigated, along with the expression of selected genes involved in plant defense mechanisms. Anthracnose incidence was reduced with CS, REO, and CS-REO emulsions after 9 days storage at 25◦C, by 8, 21, and 37%, respectively, with disease severity reduced by 22, 29, and 44%, respectively. Thus, McKinney’s decay index was reduced by 22, 30, and 44%, respectively. A protocol based on reverse transcription quantitative real-time PCR (RT-qPCR) was validated for 17 papaya target genes linked to signaling pathways that regulate plant defense, pathogenesis-related protein, cell walldegrading enzymes, oxidative stress, abiotic stress, and the phenylpropanoid pathway. CS induced gene upregulation mainly at 6 h posttreatment (hpt) and 48 hpt, while REO induced the highest upregulation at 0.5 hpt, which then decreased over time. Furthermore, CS-REO treatment delayed gene upregulation by REO alone, from 0.5 to 6 hpt, and kept that longer over time. This study suggests that CS stabilizes the volatile and/or hydrophobic substances of highly reactive essential oils. The additive effects of CS and REO were able to reduce postharvest decay and affect gene expression in papaya frui

    Bioactive compounds and techno-functional properties of high-fiber co-products of the cacao agro-industrial chain

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    The cacao shell (CS) and cacao pod husk (CPH), two of the most promising high-fiber co-products of the cacao agro-industrial chain, were evaluated to determine their potential incorporation into food products. This research determined bioactive compounds and techno-functional properties of CS and CPH, and was evaluated the enzymatic inactivation by thermal treatments in CPH. We found that CS is rich in protein, lipids, dietary fiber (48.1 ± 0.3 g 100 gdw−1), and antioxidant molecules such as epicatechin (1.10 ± 0.02 mg g−1) and isoquercetin (1.04 ± 0.09 mg g−1). Moreover, in CS a positive effect of hydration mechanism occur; in fact, it was observed a reduction of Lightness (L∗) value and a remarkable color difference (ΔE∗,18.8 ± 0.7) (CIEL∗a∗b∗ color space), between hydrated and dry CS samples; so, it could be used as a potential natural colorant in foods. CPH resulted equally rich in dietary fiber (35.3–37.4%) and flavonoids (2.9 ± 0.1 mg RE g−1); in this co-product, the rapid enzymatic inactivation by thermal treatments was essential to obtain the highest antioxidant activity and polyphenols content; regarding the techno-functional properties, it was found that CPH flour had high hydration capacity, so CPH can use it as a replacement for emulsifiers or water holding additives while incorporating the fiber and abundantly found antioxidants

    Ghanaian Cocoa (Theobroma cacao L.) Bean Shells Coproducts: Effect of Particle Size on Chemical Composition, Bioactive Compound Content and Antioxidant Activity

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    The worldwide cocoa bean shell (CBS) generation is estimated at around 900,000 tons. In their composition, this coproduct showed several bioactive compounds like methylxanthines or polyphenolic compounds. Thus, the aim of this work was to investigate the effects of different particle sizes on the chemical composition, physico-chemical, bioactive compounds content, and antioxidant properties of flours obtained from cocoa (Theobroma cacao L.) bean shells. The flours obtained from CBS with different particle sizes had high content of dietary fiber (61.18–65.58 g/100 g). The polyphenolic profile identified seven compounds being epicatechin and catechin (values ranged 4.56–6.33 and 2.11–4.56 mg/g, respectively) as the most abundant compounds. Additionally, the methylxanthines theobromine and caffeine were quantified with values ranging from 7.12 to 12.77 and 4.02 to 6.13 mg/g, respectively. For the fatty acid profile, the principal compounds identified were oleic, stearic and palmitic acids. CBS had antioxidant capacity with all methods assayed. For DPPH, ABTS and FRAP assays values ranged between 2.35–5.53, 3.39–11.55, and 3.84–7.62 mg Trolox equivalents/g sample, respectively. This study suggests that cocoa bean shells may constitute a valuable coproduct for the food industry due to its high content in valuable bioactive compounds

    Cacao Pod Husk Flour as an Ingredient for Reformulating Frankfurters: Effects on Quality Properties

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    The cocoa pod husk is considered a source of dietary fiber with a high content of water-soluble pectins, bioactive compounds which should be viewed as a by-product with the potential to be incorporated into food. This study aimed to investigate the effect of adding different cocoa pod husk flour (CPHF) levels as a starch replacement for reformulating frankfurters. Results showed that the addition of 1.5 and 3.0% pod husk proportionally increased the frankfurter's fiber content by 0.49 ± 0.08 and 0.96 ± 0.19 g/100 g, which is acceptable for a product that does not contain fiber. Textural properties and sensory characteristics were affected when substituting the starch with CPHF, either totally or partially, although these samples had higher water content, hardness, and adhesiveness while springiness decreased. Non-adverse effects of nitrite on polyphenolic compounds content were evidenced in samples enriched with CPHF. The incorporation of CPHF did not significantly affect the color parameters (DeltaE < 3). Finally, the panelists indicated a sensation of the unsalted sausage, suggesting that CPHF may have natural mucoadhesion properties. In conclusion, in formulated meat products such as sausages, plant co-products such as cacao pod husks could be a valid new ingredient to improve technological parameters, functional characteristics, and stability

    Bioactive micro-constituents of ackee arilli (Blighia sapida K.D. Koenig)

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    Abstract: Ackee (Blighia sapida K. D. Koenig) is an exotic fruit widely consumed in the Caribbean countries. While there is extensive research on the presence of hypoglycin A, other bioactive compounds have not been studied. We identified and quantified the changes in bioactive molecules (total phenol, ascorbic acid, hypoglycin A, squalene, D: A-Friedooleanan-7-ol, (7.alpha.), and oleic acid), antioxidant potential, and volatile compounds during two stages of ripe. A clear reduction in hypoglycin A, ascorbic acid, and total polyphenols during the maturation process were observed. On the contrary, oleic acid, squalene, and D: A-Friedooleanan-7-ol, (7.alpha.) contents increased about 12, 12, and 13 times, respectively with advancing maturity. These bioactive molecules were positively correlated with radical scavenging (DDPH and ABTS). Solid phase microextraction (SPME) and gas chromatography coupled mass spectrometry (GC/MS) analysis revealed more than 50 compounds with 3-penten-2-one and hexanal as the major compounds in the fully ripe stage. The results suggested that ripe ackee arilli could serve as an appreciable source of natural bioactive micro-constituents

    salmonella enterica control in stick carrots through incorporation of coriander seeds essential oil in sustainable washing treatments

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    Chemical disinfectants represent one of the commonly used practice in minimal processed vegetables food-chain. However, the scarce safety and sustainability of these agents force food industry to move toward more sustainable "green washing solutions". Among the latter, while the application of plant derivates for the control of several pathogens is already well-known, specific information on the potential anti-Salmonella activity of Coriandrum sativum seeds derivates are still limited and were therefore investigated in this study. In detail, Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) of different coriander seed derivates (i.e. essential oil, hydrosol and ethanolic extract) were determined by broth dilution against six Salmonella enterica strains isolated from fresh and minimally processed fruits and vegetables. Only the essential oil (EO) was effective in vitro with strain-dependent results. In addition, when mixed in co-culture, the strains were more sensitive to the essential oil treatment. Chemical investigations allowed to define (s)-(+)-linalool as major compound, and to underline interesting phenolic content with correlated antioxidant capacity. A cocktail of three strains of different serovars was selected and employed for a preliminary in situ trial on stick carrots. The obtained results allowed to establish that the application of coriander seed EO at concentrations of 5 µL mL-1 was able to reduce and contain the growth of the Salmonella cocktail up to 24 hours at 10°C. Good sensory evaluation results were obtained by applying this EO concentration as washing treatment, especially in terms of color parameter. Further studies should be undertaken to emphasize the upstream activity, improving the formulation or exploiting a combined effect with other sanitizers or treatments (e.g. physical treatments). The present study contributes to the knowledge on coriander derivates activity against Salmonella spp. and on the potential application as sustainable washing treatment in removing this pathogen from fresh cut carrots
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