A pilot study: consumer acceptability of Polish style cooked sausages containing house cricket flour

There is a growing interest on insects as food in Western countries. Currently, EU legislation limits the use of insects as food, however, new regulation coming to force in 2018 will clarify the situation. In the ScenoProt project funded by Strategic Research Council of Finnish Academy insects are considered as potential protein source for human consumption, and therefore, some food technological properties of insects are studied in the project. Scientific research has proven mealworm larvae and silkworm pupae originated protein fraction equal to meat protein in emulsion sausages. Generally, it is also of interest how unfractionated, chitin containing insect flour would affect the sensory properties of sausages. The objective of the present study was to investigate the consumer attitudes to Polish style sausages containing unfractionated house cricket (Acheta domesticus) flour. Lean and fatty meat was purchased from local supplier, and three different sets of smoked and cooked sausages were made. The basic recipe contained pork, water, house cricket flour, nitrite salt, and spices. Salt content of sausages was approx. 1.8%. In the first set 1/5, and in the second and third set approx. 1/6 of lean meat was replaced with house cricket flour. The fat content was approx. 12% in the first and 19–20% in the second and third set of sausages. The third set included ordinary Polish style sausage as a reference. Cooking loss of the sausages was acceptable, below 10%. Odor, texture and taste were evaluated by ordinary consumers (n=26) for the first, by media people (n=34) for the second, and by representatives of food industry (n=17) for the third set. Because of potential allergic reaction in shellfish sensitive people, the consumers were informed about the contents of the sausages. Consumer willingness to eat sausages again was recorded for the first and second set and free comments were collected for all the sets. The evaluation scale had five points (1=extremely negative, 5=extremely positive).Only in the first set the evaluations on odor, texture, and taste of the sausages averaged lower than 3. Even the willingness to eat sausages again was approx. 3. This may reflect the interest of the consumers towards food containing insects in general. The increased fat content in the second and third sets of sausages may be one factor responsible for increase in the valuation of the sensory parameters as Finnish consumers are used to the fat content of around 20 % in cooked sausages. In the third set the control sausages showed slightly higher acceptance for texture than the house cricket sausages. In free comments, dryness, dark colour, floury texture, and liver flavor were most often mentioned. In conclusion, consumers may accept non-fractionated house cricket flour as a sausage ingredient but its strong flavor may limit the level of inclusion or lead towards stronger, masking, spicing in the house cricket sausages

Specific Lhc Proteins Are Bound to PSI or PSII Supercomplexes in the Diatom Thalassiosira pseudonana

Despite the ecological relevance of diatoms, many aspects of their photosynthetic machinery remain poorly understood. Diatoms differ from the green lineage of oxygenic organisms by their photosynthetic pigments and light-harvesting complex (Lhc) proteins, the latter of which are also called fucoxanthin-chlorophyll proteins (FCP). These are composed of three groups of proteins: Lhcf as the main group, Lhcr that are PSI associated, and Lhcx that are involved in photoprotection. The FCP complexes are assembled in trimers and higher oligomers. Several studies have investigated the biochemical properties of purified FCP complexes, but limited knowledge is available about their interaction with the photosystem cores. In this study, isolation of stable supercomplexes from the centric diatom Thalassiosira pseudonana was achieved. To preserve in vivo structure, the separation of thylakoid complexes was performed by native PAGE and sucrose density centrifugation. Different subpopulations of PSI and PSII supercomplexes were isolated and their subunits identified. Analysis of Lhc antenna composition identified Lhc(s) specific for either PSI (Lhcr 1, 3, 4, 7, 10-14, and Lhcf10) or PSII (Lhcf 1-7, 11, and Lhcr2). Lhcx6_1 was reproducibly found in PSII supercomplexes, whereas its association with PSI was unclear. No evidence was found for the interaction between photosystems and higher oligomeric FCPs, comprising Lhcf8 as the main component. Although the subunit composition of the PSII supercomplexes in comparison with that of the trimeric FCP complexes indicated a close mutual association, the higher oligomeric pool is only weakly associated with the photosystems, albeit its abundance in the thylakoid membrane

Monipuolisuus lautasella on monipuolisuutta pellolla

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CRK2 enhances salt tolerance in Arabidopsis thaliana by regulating endocytosis and callose deposition in connection with PLDα1

Peer reviewe

Gel-based proteomic map of Arabidopsis thaliana root plastids and mitochondria

Background Non-photosynthetic plastids of plants are known to be involved in a range of metabolic and biosynthetic reactions, even if they have been difficult to study due to their small size and lack of color. The morphology of root plastids is heterogeneous and also the plastid size, density and subcellular distribution varies depending on the cell type and developmental stage, and therefore the functional features have remained obscure. Although the root plastid proteome is likely to reveal specific functional features,Arabidopsis thalianaroot plastid proteome has not been studied to date. Results In the present study, we separated Arabidopsis root protein fraction enriched with plastids and mitochondria by 2D-PAGE and identified 84 plastid-targeted and 77 mitochondrion-targeted proteins using LC-MS/MS. The most prevalent root plastid protein categories represented amino acid biosynthesis, carbohydrate metabolism and lipid biosynthesis pathways, while the enzymes involved in starch and sucrose metabolism were not detected. Mitochondrion-targeted proteins were classified mainly into the energetics category. Conclusions This is the first study presenting gel-based map ofArabidopsis thalianaroot plastid and mitochondrial proteome. Our findings suggest that Arabidopsis root plastids have broad biosynthetic capacity, and that they do not play a major role in a long-term storage of carbohydrates. The proteomic map provides a tool for further studies to compare changes in the proteome, e.g. in response to environmental cues, and emphasizes the role of root plastids in nitrogen and sulfur metabolism as well as in amino acid and fatty acid biosynthesis. The results enable taking a first step towards an integrated view of root plastid/mitochondrial proteome and metabolic functions inArabidopsis thalianaroots

Changes in cardiac proteome and metabolome following exposure to the PAHs retene and fluoranthene and their mixture in developing rainbow trout alevins

Exposure to polycyclic aromatic hydrocarbons (PAHs) is known to affect developing organisms. Utilization of different omics-based technologies and approaches could therefore provide a base for the discovery of novel mechanisms of PAH induced development of toxicity. To this aim, we investigated how exposure towards two PAHs with different toxicity mechanisms: retene (an aryl hydrocarbon receptor 2 (Ahr2) agonist), and fluoranthene (a weak Ahr2 agonist and cytochrome P450 inhibitor (Cyp1a)), either alone or as a mixture, affected the cardiac proteome and metabolome in newly hatched rainbow trout alevins (Oncorhynchus mykiss). In total, we identified 65 and 82 differently expressed proteins (DEPs) across all treatments compared to control (DMSO) after 7 and 14 days of exposure. Exposure to fluoranthene altered the expression of 11 and 19 proteins, retene 29 and 23, while the mixture affected 44 and 82 DEPs by Days 7 and 14, respectively. In contrast, only 5 significantly affected metabolites were identified. Pathway over-representation analysis identified exposure-specific activation of phase II metabolic processes, which were accompanied with exposure-specific body burden profiles. The proteomic data highlights that exposure to the mixture increased oxidative stress, altered iron metabolism and impaired coagulation capacity. Additionally, depletion of several mini-chromosome maintenance components, in combination with depletion of several intermediate filaments and microtubules, among alevins exposed to the mixture, suggests compromised cellular integrity and reduced rate of mitosis, whereby affecting heart growth and development. Furthermore, the combination of proteomic and metabolomic data indicates altered energy metabolism, as per amino acid catabolism among mixture exposed alevins; plausibly compensatory mechanisms as to counteract reduced absorption and consumption of yolk. When considered as a whole, proteomic and metabolomic data, in relation to apical effects on the whole organism, provides additional insight into PAH toxicity and the effects of exposure on heart structure and molecular processes.</p

The L1TD1 Protein Interactome Reveals the Importance of Post-transcriptional Regulation in Human Pluripotency

Peer reviewe

Hypoxia reveals a new function of Foxn1 in the keratinocyte antioxidant defense system

Skin exposed to environmental threats, including injuries and oxidative stress, develops an efficient but not fully recognized system of repair and antioxidant protection. Here, using mass spectrometry analysis (LC–MS/MS), followed by in vitro and in vivo experiments, we provided evidence that Foxn1 in keratinocytes regulates elements of the electron transport chain and participates in the thioredoxin system (Txn2, Txnrd3, and Srxn1) induction, particularly in a hypoxic environment. We first showed that Foxn1 in keratinocytes upregulates glutathione thioredoxin reductase 3 (Txnrd3) protein expression, and high levels of Txnrd3 mRNA were detected in injured skin of Foxn1+/+ mice. We also showed that Foxn1 strongly downregulated the Ccn2 protein expression, participating in epidermal reconstruction after injury. An in vitro assay revealed that Foxn1 controls keratinocyte migration, stimulating it under normoxia and suppressing it under hypoxia. Keratinocytes overexpressing Foxn1 and exposed to hypoxia displayed a reduced ability to promote angiogenesis by downregulating Vegfa expression. In conclusion, this study showed a new mechanism in which Foxn1, along with hypoxia, participates in the activation of antioxidant defense and controls the functional properties of keratinocytes. </p

Orphan G protein-coupled receptor GPRC5A modulates integrin β1-mediated epithelial cell adhesion

G-Protein Coupled Receptor (GPCR), Class C, Group 5, Member A (GPRC5A) has been implicated in several malignancies. The underlying mechanisms, however, remain poorly understood. Using a panel of human cell lines, we demonstrate that CRISPR/Cas9-mediated knockout and RNAi-mediated depletion of GPRC5A impairs cell adhesion to integrin substrates: collagens I and IV, fibronectin, as well as to extracellular matrix proteins derived from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma (Matrigel). Consistent with the phenotype, knock-out of GPRC5A correlated with a reduced integrin β1 (ITGB1) protein expression, impaired phosphorylation of the focal adhesion kinase (FAK), and lower activity of small GTPases RhoA and Rac1. Furthermore, we provide the first evidence for a direct interaction between GPRC5A and a receptor tyrosine kinase EphA2, an upstream regulator of FAK, although its contribution to the observed adhesion phenotype is unclear. Our findings reveal an unprecedented role for GPRC5A in regulation of the ITGB1-mediated cell adhesion and it's downstream signaling, thus indicating a potential novel role for GPRC5A in human epithelial cancers.</p

Data-Independent Acquisition Mass Spectrometry in Metaproteomics of Gut Microbiota—Implementation and Computational Analysis

Metagenomic approaches focus on taxonomy or gene annotation but lack power in defining functionality of gut microbiota. Therefore, metaproteomics approaches have been introduced to overcome this limitation. However, the common metaproteomics approach uses data-dependent acquisition mass spectrometry, which is known to have limited reproducibility when analyzing samples with complex microbial composition. In this work, we provide a proof-of-concept for data-independent acquisition (DIA) metaproteomics. To this end, we analyze metaproteomes using DIA mass spectrometry and introduce an open-source data analysis software package diatools, which enables accurate and consistent quantification of DIA metaproteomics data. We demonstrate the feasibility of our approach in gut microbiota metaproteomics using laboratory assembled microbial mixtures as well as human fecal samples. </p