Milk protein production by a more environmentally sustainable process : bipolar membrane electrodialysis coupled with ultrafiltration

The increased demand for food production to nourish the rapidly growing human population raises serious sustainability issues for the food sector. Indeed, conventional food production lines involve processes having a significant environmental burden. Hence, the present study aims to demonstrate an environmentally sustainable process of food production. The milk protein was chosen as a model food ingredient due to its exceptional role in the human diet. The proposed innovative process of milk protein production includes bipolar membrane electrodialysis coupled with ultrafiltration (EDBM-UF). The crucial problem during the EDBM-UF of milk, such as different types of membrane fouling, was successfully solved. Moreover, the life cycle assessment of the novel EDBM-UF protein production process was carried out and compared to a conventional acid/base process. Additionally, a sensitivity test of electricity supply at different geographical locations of the world was performed since electricity is the main energy source for the EDBM-UF process and it could be derived from different sources (renewable and non-renewable). The assessment results demonstrate that the proposed electromembrane process has significant environmental benefits compared to the conventional process using chemicals independently from the electricity supply mix from all considered geographical locations. Thus, EDBM-UF could become a prospective industrial technology taking into account environmental concerns and promoting the development of healthy human society

Inhibitory effects of commercial and enriched green tea extracts on the growth of Brochothrix thermosphacta, Pseudomonas putida and Escherichia coli

The major catechin found in green tea, called epigallocatechin gallate (EGCG), have been reported to have antimicrobial properties. In this study, we examined in vitro the antimicrobial effects of a commercial green tea extract sold in a capsule form, and two prepared green tea extracts enriched in catechins against Brochothrix thermosphacta, Pseudomonsas putida and Escherichia coli which have been associated with meat spoilage. The antimicrobial activity of the different tea extracts was evaluated by Spot-On-Lawn and Well Diffusion assays and the Minimum Inhibitory Concentration (MIC) was also determined in Brain Heart Infusion broth. The three methods used showed an inhibition of Brochothrix thermosphacta, whereas the inhibition of Pseudomonas putida and Escherichia coli was only detected with the MIC assay. The determination of the MIC in broth culture appeared to be the most reliable method to determine the inhibitory activity of catechin compounds

Phospholipid r ecovery from sweet whey and whey protein concentrate: Use of electrodialysis with bipolar membrane combined with a dilution factor as an ecoefficient method

Electrodialysis with bipolar membrane (EDBM) is promising to recover phospholipids (PLs) from sweet whey and whey protein concentrate (WPC), as it promotes lipoprotein complex formation following a decrease in pH and ionic strength. The aim of this work was to study the impact of dilution factor (without dilution, with a 2X, 4X and 6X dilution) after EDBM on the process performances. For both products, a 4X dilution, which cor- responds to a decrease in ionic strength of 81.4 ± 1.5 % for sweet whey and 79.4 ± 0.4 % for WPC, seemed sufficient to maximize lipoprotein complex formation as a plateau was reached in the defatting rates. Further- more, it was demonstrated that the process could be used to recover PLs. Higher PL contents were found in the precipitates recovered from sweet whey combined with a dilution: highest contents in total PLs for WPC (7.45 ± 0.49 and 8.00 ± 0.49 g/100g with a 4X-6X dilution) were not different from the lowest content for sweet whey (7.50 ± 1.18 g/100 g without dilution). For both products, the main PLs recovered were phos- phatidylethanolamine and phosphatidylserine, which respectively represented between 42.0 ± 1.7 and 51.6 ± 2.3 % and 30.1 ± 2.2 to 38.7 ± 0.8 % of total PLs. Furthermore, considering their high ecoefficiency scores, sweet whey combined with a 2X or 4X dilution are the most promising conditions

Towards water, sodium chloride and natural organic matter recovery from ion exchange spent brine

ABSTRACT: Despite the tremendous success of the application of anion exchange resins (IX) in natural organic matter (NOM) removal over conventional removal methods, the considerable amount of brine spent during its regeneration cycle makes its sustainability questionable. This polluting saline stream can be challenging to manage and costly to discharge. Alternatively, and with the recent shift in perception of resource recovery, the produced spent brine can no longer be seen as a polluting waste but as an unconventional source of water, minerals and nutrients. In this research, for the first time, we evaluated the effectiveness of an integrated monovalent selective electrodialysis (MSED) and direct contact membrane distillation (DCMD) system in IX spent brine desalination and resource recovery. Of particular interest were the effects of operating time on the characteristics of the monovalent permselective ion exchange membranes, the impact of the DCMD stack configuration on minimizing heat loss to the ambient environment and the efficacy of the recovered NaCl in the regenerating cycle of the exhausted IXs. Our findings demonstrated that although the recovered NaCl from the stand-alone MSED can restore nearly 60% ion exchange capacity of the exhausted IXs, coupling MSED with DCMD led to minimizing the consumption of fresh NaCl (in the IX regeneration cycle) significantly, the potential application of NOM in agriculture and diminishing the risk of the IX spent brine disposal. In addition, the initial characteristics of the ion permselective membranes were maintained after 24 h of MSED and the transmembrane flux was increased when the feed/hot compartment (in the DCMD stack) was encapsulated on two outer ends with coolant/permeate compartments as a result of less heat loss to the ambient environment

Molecular phylogeny and timing of diversification in Alpine Rhithrogena (Ephemeroptera: Heptageniidae).

BACKGROUND: Larvae of the Holarctic mayfly genus Rhithrogena Eaton, 1881 (Ephemeroptera, Heptageniidae) are a diverse and abundant member of stream and river communities and are routinely used as bio-indicators of water quality. Rhithrogena is well diversified in the European Alps, with a number of locally endemic species, and several cryptic species have been recently detected. While several informal species groups are morphologically well defined, a lack of reliable characters for species identification considerably hampers their study. Their relationships, origin, timing of speciation and mechanisms promoting their diversification in the Alps are unknown. RESULTS: Here we present a species-level phylogeny of Rhithrogena in Europe using two mitochondrial and three nuclear gene regions. To improve sampling in a genus with many cryptic species, individuals were selected for analysis according to a recent DNA-based taxonomy rather than traditional nomenclature. A coalescent-based species tree and a reconstruction based on a supermatrix approach supported five of the species groups as monophyletic. A molecular clock, mapped on the most resolved phylogeny and calibrated using published mitochondrial evolution rates for insects, suggested an origin of Alpine Rhithrogena in the Oligocene/Miocene boundary. A diversification analysis that included simulation of missing species indicated a constant speciation rate over time, rather than any pronounced periods of rapid speciation. Ancestral state reconstructions provided evidence for downstream diversification in at least two species groups. CONCLUSIONS: Our species-level analyses of five gene regions provide clearer definitions of species groups within European Rhithrogena. A constant speciation rate over time suggests that the paleoclimatic fluctuations, including the Pleistocene glaciations, did not significantly influence the tempo of diversification of Alpine species. A downstream diversification trend in the hybrida and alpestris species groups supports a previously proposed headwater origin hypothesis for aquatic insects

Essential omega-3 fatty acids tune microglial phagocytosis of synaptic elements in the mouse developing brain

AbstractOmega-3 fatty acids (n-3 PUFAs) are essential for the functional maturation of the brain. Westernization of dietary habits in both developed and developing countries is accompanied by a progressive reduction in dietary intake of n-3 PUFAs. Low maternal intake of n-3 PUFAs has been linked to neurodevelopmental diseases in Humans. However, the n-3 PUFAs deficiency-mediated mechanisms affecting the development of the central nervous system are poorly understood. Active microglial engulfment of synapses regulates brain development. Impaired synaptic pruning is associated with several neurodevelopmental disorders. Here, we identify a molecular mechanism for detrimental effects of low maternal n-3 PUFA intake on hippocampal development in mice. Our results show that maternal dietary n-3 PUFA deficiency increases microglia-mediated phagocytosis of synaptic elements in the rodent developing hippocampus, partly through the activation of 12/15-lipoxygenase (LOX)/12-HETE signaling, altering neuronal morphology and affecting cognitive performance of the offspring. These findings provide a mechanistic insight into neurodevelopmental defects caused by maternal n-3 PUFAs dietary deficiency.Infrastructure de Recherche Translationnelle pour les Biothérapies en NeurosciencesProgram Initiative d’Excellenc

Special Issue “Membrane Technologies for Sustainable Biofood Production Lines”

Population growth and urbanization present serious challenges for the biofood sectors since there will be a 70% increase in the global demand by 2050 [...

Fouling prevention of peptides from a tryptic whey hydrolysate during electromembrane processes by use of monovalent ion permselective membranes

Peptide adsorption occurring on conventional anion- and cation-exchange membranes is one of the main technological locks in electrodialysis (ED) for hydrolysate demineralization. Hence, the peptide fouling of monovalent anion (MAP) and monovalent cation (MCP) permselective membranes was studied and compared to conventional membranes (AMX-SB and CMX-SB). It appeared that the main peptide sequences responsible for fouling were TPEVDDEALEKFDK, VAGTWY and VLVLDTDYK for both anionic membranes; and ALPMHIR and TKIPAVFK for both cationic membranes. However based on the MS-MS results, the fouling was about 97–100% lower for MAP than AMX-SB and 95–100% lower for MCP than CMX-SB. This was explained by the differences in charge sign distribution at the membrane surface. Consequently, monovalent membranes can represent a very interesting opportunity for treatment of hydrolysate solution in electrodialytic processes by practically eliminating peptide fouling. At our knowledge, it was the first time that such a demonstration was done