Search results for "Biot"

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…

Infection by Endosymbiotic “Male-Killing” Bacteria in Coleoptera

2018

Wolbachia, Rickettsia, Spiroplasma and Cardinium are endosymbiotic and intracellular bacteria known to cause numerous disorders in host reproduction, reflected in their common name “male-killers”. In this study, 297 beetle species from various taxonomic groups were screened with the use of molecular markers for the presence of infection by any of these endosymbionts. Wolbachia was found to be the most common “male-killer” among beetle hosts as it infected approx. 27% of species. Rickettsia, Spiroplasma and Cardinium were much less prevalent as they infected: 8%, 3% and 2%, respectively, of the studied beetle species. This is the first report of Cardinium presence in beetle hosts. Incidences…

Valorisation of Persimmon and Blueberry By-Products to Obtain Functional Powders: in vitro Digestion and Fermentation by Gut Microbiota

2020

[EN] Globalization of fruit and vegetable markets generates overproduction, surpluses, and potentially valuable residues. The valorization of these byproducts constitutes a challenge, to ensure sustainability and reintroduce them into the food chain. This work focuses on blueberry and persimmon residues, rich in polyphenols and carotenoids, to obtain powders with high added value to be used as ingredients in food formulation. These powders have been characterized, and the changes in the bioactive compounds in in vitro gastrointestinal digestion have been evaluated. The results indicated that the type of residue, the drying process, as well as the content and type of fiber determine the rele…

Fast pyrolysis of hot-water-extracted and soda-AQ-delignified okra (Abelmoschus esculentus) and miscanthus (miscanthus x giganteus) stalks by Py-GC/MS

2018

Abstract The thermochemical behavior of various samples of okra ( Abelmoschus esculentus ) and miscanthus ( Miscanthus x giganteus ) stalks (initial, hot-water-extracted, and those from sulfur-free delignification) were studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). In all cases, major GC-amenable condensable products were measured semi-quantitatively and classified into several product groups. The formation of these product groups from different feedstock samples with varying mass portions of their structural constituents (carbohydrates and lignin) was investigated at 500 °C and 700 °C with a residence time of 5 s and 20 s. The main product groups were aliphatic comp…

Effects of almond gum as texture and sensory quality improver in wheat bread

2016

International audience; The aim of this work was to investigate the effect of almond gum as dietary fibre source in enhancing the wheat bread quality. Different amounts of almond gum (2%, 5% and 10% (w/w)) were used in bread formulation. The volume, texture, crust and crumb colour, as well as the sensorial properties, were evaluated and compared to control (without almond gum). The obtained results showed that almond gum addition enhanced significantly the volume of bread. The highest volume was obtained using 2% almond gum concentration with 23.6% increase, compared to control. Using almond gum in bread formulation improved considerably its texture with a notable decrease in hardness by 61…

Gamma Irradiation and Fermentation

2016

This chapter discusses the applications of gamma irradiation technology for food safety, its nutritional implications, and its involvement in fermentation processes. Gamma irradiation has become an alternative technology for food sterilization due to its nonthermal character, thus replacing the conventional heating processes. Several driving forces are propelling the need of γ-irradiation forward for food applications. Besides food preservation, γ-irradiation is taking place for novel applications, especially involving the enhancement of food fermentation processes, by directly irradiating the medium, or generating performant genetically modified strains.

Foreword

2007

Interaction of Oily Water with Floating Porous Ceramic and Immobilized Microorganisms

2018

Oily water was treated with porous ceramic granules and immobilized microorganisms. Floating granules with bulk density of 0.63-0.66 g cm-3were used. The sorption of motor oil was investigated for dry and wetted granules. Respiration experiments showed that microorganisms immobilized on floating ceramic carrier and treated with oily water were influenced by agitation of liquid. The treatment of oily water with low salinity (1-9 g L-1) showed that oil removal efficiency decreased after increasing water salinity. Likewise, oil removal efficiency decreased from 12 to 9% per gram of ceramic carrier after increasing the spill of oil from 9 to 35 g per square meter. Porous granules with immobiliz…