Search results for "0404 agricultural biotechnology"
showing 10 items of 1115 documents
Characterization of kefir-like beverages produced from vegetable juices
2016
The aim of this work was to develop new non-dairy fermented beverages using vegetable juices as fermentable substrates. Carrot, fennel, melon, onion, tomato and strawberry juices underwent back-slopping fermentations, carried out by water kefir microorganisms. Results indicated that lactic acid bacteria and yeasts were capable of growing in the juices tested. Melon juice registered the highest numbers of microorganisms. Almost all juices underwent a lactic fermentation. After fermentation, there was observance of a decrease of the soluble solid content and an increase of the number of volatile organic compounds. In particular, esters were present in high amounts after the fermentation, espe…
The antioxidant power of horseradish, Armoracia rusticana, underlies antimicrobial and antiradical effects, exerted in vitro
2018
Armoracia rusticana (AR) was tested for antimicrobial and antioxidants power. The compound demonstrated to inhibit fish pathogens such as Vibrio anguillarum, V. harvey, V. alginolyticus, Aeromonas hydrophila, A. salmonicida, Photobacterium damselae subspecie piscicida, Tenacibaculum marinum and Pseudomonas anguilliseptica,. The total phenolic content and the reducing power resulted higher in the water extract of AR, respect to the hydroalcoolic. In vitro test demonstrated that AR significantly protect cells against death, induced by oxidative stress.
Oxidation in wine: Does expertise influence the perception?
2019
International audience; Wines can develop off-odours that depreciate their quality. Among them, oxidation is one of the most prevalent. The main objective of this work was to study the perception of wine oxidation through the categorization of oxidized wines perceived as not-faulty/faulty depending on the expertise of participants. For this purpose, one white wine and one red wine were spiked with three volatile oxidation compounds (acetaldehyde, phenylacetaldehyde and methional) in order to recreate twelve levels of oxidation in a controlled way. Samples were submitted to orthonasal tasting for being categorized by wine experts and novices and coupled to a free description task. Results de…
New challenges and opportunities of food fermentation processes: Application of conventional and innovative techniques.
2019
International audience
A microbiological, physicochemical, and texture study during storage of yoghurt produced under isostatic pressure
2019
Abstract This work aimed to study refrigeration storage (4 °C for 23 days) of yoghurt produced at 43 °C under sub-lethal high pressure, at 10, 20, 30 and 40 MPa, in comparison with the fermentation process at atmospheric pressure (0.1 MPa). Lactic acid bacteria (S. thermophilus and L. bulgaricus, LAB) and quality parameters like pH, titratable acidity, syneresis and colour were evaluated, along with textural analyses to infer how pressure would impact the obtained yoghurt along storage. Higher fermentation pressures resulted in slightly lower LAB loads (a maximum of 1.01 Log (CFU/mL)) and increased the fermentation time (a maximum of 3 h 25 min), syneresis (a maximum of 44%), all for 40 MPa…
Note. Kinetic parameters of Bacillus stearothermophilus spores under isothermal and non-isothermal heating conditions Nota. Parámetros cinéticos del …
1998
Thermobacteriological studies using Bacillus stearotherrnophilus spores were carried out by heating the spores under isothermal and non-isothermal conditions followed by an isothermal period. Ex perimental data obtained after isothermal heating were analyzed using a two-step linear regression procedure and a one-step nonlinear regression method. Results obtained using both analytical tech niques were close, but the 90% interval of confidence for predictions was lower when the one-step nonlinear regression was used. These results indicated the convenience of using the one-step nonlin ear regression method to obtain thermal kinetic parameters for bacterial spores. Also, the parameters obtain…
Antifungal activity of peracetic acid against toxigenic fungal contaminants of maize and barley at the postharvest stage
2021
Abstract Contamination of maize and barley grain during storage by the toxigenic fungi Aspergillus flavus (A. flavus) and Penicillium Verrucosum (P. verrucosum) is both an economic and a public health problem, especially in less industrialized countries. Peracetic acid (PA) is a compound used for the disinfection of food and food contact surfaces. Unlike other disinfectants, it leaves no toxic residues and its decomposition products (CH3COOH, O2 and H2O) are environmentally friendly. In order to apply PA to preserve maize and barley grain during storage, first, the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) against both fungi were determined in a 96-we…
Biopreservation of tomatoes using fermented media by lactic acid bacteria
2020
Abstract Post-harvest spoilage fungi in tomatoes represent an economic loss for industry and consumers. There is currently an increasing demand for novel applications of bio-preservatives as replacers of chemical additives and pesticides in food. In this study, nine lactic acid bacteria strains isolated from tomato and sourdough were screened for antifungal activity in vitro against 33 fungal strains and used as bio-preservatives of tomato inoculated with Penicillium expansum and Aspergillus flavus. The identification of the compounds potentially responsible for the antifungal activity, such as organic acids, phenolic acids and volatile organic compounds (VOCs), were identified and quantifi…
Enzyme inactivation and evaluation of physicochemical properties, sugar and phenolic profile changes in cloudy apple juices after high pressure proce…
2019
The effect of high pressure processing (HPP) (200–600 MPa/5–45°C/1–15 min) on the enzyme activity and some quality parameters of cloudy apple juice during subsequent storage (4°C for 12 weeks) was investigated. Statistical analysis showed that pressure, temperature, and time had a significant effect (p < 0.05) on tissue enzyme activity, decreasing the activity of polyphenol oxidases (PPO) and peroxidases (POD). No significant changes in physicochemical parameters (pH, total soluble solids, sugars, and vitamin C) were observed after HPP treatments. The main polyphenols detected in apple juice were dichydrochalcones, being phloridzin the predominant (48.8 mg/L), and flavanols, with the highes…
Evaluation of microbiological and physico‐chemical parameters of retail ready‐to‐eat mono‐varietal salads
2019
An integrated microbiological and physico-chemical approach was applied to evaluate the decay of mono-varietal ready-to-eat escarole (Cichorium endivia var. latifolium) and red chicory (Cichorium intybus L. var. foliosum Hegi) during refrigeration. Total mesophilic microorganisms, including pseudomonads, and total psychrotrophic microorganisms were detected at high numbers in all samples just after packaging and at the expiry date. The dominant microbial populations analyzed by classical culture-dependent methods belonged to Pseudomonas and yeasts. Illumina sequencing identified Janthinobacterium lividum and Pseudomonas veronii as main species. Regarding the physico-chemical quality between…