Contribution of mono- and co-culture of Pseudomonas paralactis, Acinetobacter MN21 and Stenotrophomonas maltophilia to the spoilage of chill-stored lamb.

Exploring the contribution of common microorganisms to spoilage is of great significance in inhibiting spoilage in lamb. This work investigated the extent of protein degradation and profile changes of free amino acids (FAAs), free fatty acids (FFAs) and volatile organic compounds (VOCs) in lamb caused by single- and co-culture of the common aerobic spoilage bacteria, P. paralactis, Ac. MN21 and S. maltophilia. Meanwhile, some key VOCs produced by the three bacteria during lamb spoilage were also screened by orthogonal partial least square discriminant analysis and difference value in VOCs content between inoculated groups and sterile group. Lamb inoculated with P. paralactis had the higher total viable counts, pH, total volatile base nitrogen and TCA-soluble peptides than those with the other two bacteria. Some FAAs and FFAs could be uniquely degraded by P. paralactis but not Ac. MN21 and S. maltophilia, such as Arg, Glu, C15:0, C18:0 and C18:1n9t. Co-culture of the three bacteria significantly promoted the overall spoilage, including bacterial growth, proteolysis and lipolysis. Key VOCs produced by P. paralactis were 2, 3-octanedione, those by Ac. MN21 were 1-octanol, octanal, hexanoic acid, 1-pentanol and hexanoic acid methyl ester, and that by S. maltophilia were hexanoic acid. The production of extensive key-VOCs was significantly and negatively correlated with C20:0, C23:0 and C18:ln9t degradation. This study can provide a basis for inhibiting common spoilage bacteria and promoting high-quality processing of fresh lamb.

Metabolomic evolution of the postpartum dairy cow uterus.

High rates of early pregnancy loss are a critical issue in dairy herds, particularly in seasonal, grazing systems. Components of the uterine luminal fluid (ULF), on which the early embryo depends for sustenance and growth, partly determine early pregnancy losses. Here, changes in ULF from early to mid-postpartum in crossbred dairy cows were explored, linking them with divergent embryo development. For this, the uteri of 87 cows at Day 7 of pregnancy at first and third estrus postpartum were flushed to collect ULF. Eighteen metabolites (chiefly organic acids and sugars) significantly varied in abundance across postpartum, indicating a molecular signature of physiological recovery consistent of the upregulation of pyrimidine metabolism and glycerophospholipid metabolism, and downregulation of pentose phosphate and taurine metabolism pathways. Joint pathway analysis of metabolomics data and a previously generated proteomics data set on the same ULF samples suggests key links between postpartum recovery and subsequent successful embryo development. These include upregulation of VEGFA and downregulation of metabolism, NRF2, T-cell receptor, which appear to improve the ULF's capacity of sustaining normal embryo development, and a putative osmo-protectant role of beta-alanine. These relationships should be further investigated to develop tools to detect and reduce early pregnancy loss in dairy cows.

The fourth industrial revolution in the food industry-part II: Emerging food trends.

The food industry has recently been under unprecedented pressure due to major global challenges, such as climate change, exponential increase in world population and urbanization, and the worldwide spread of new diseases and pandemics, such as the COVID-19. The fourth industrial revolution (Industry 4.0) has been gaining momentum since 2015 and has revolutionized the way in which food is produced, transported, stored, perceived, and consumed worldwide, leading to the emergence of new food trends. After reviewing Industry 4.0 technologies (e.g. artificial intelligence, smart sensors, robotics, blockchain, and the Internet of Things) in Part I of this work (Hassoun, Aït-Kaddour, et al. 2022. The fourth industrial revolution in the food industry-Part I: Industry 4.0 technologies. Critical Reviews in Food Science and Nutrition, 1-17.), this complimentary review will focus on emerging food trends (such as fortified and functional foods, additive manufacturing technologies, cultured meat, precision fermentation, and personalized food) and their connection with Industry 4.0 innovations. Implementation of new food trends has been associated with recent advances in Industry 4.0 technologies, enabling a range of new possibilities. The results show several positive food trends that reflect increased awareness of food chain actors of the food-related health and environmental impacts of food systems. Emergence of other food trends and higher consumer interest and engagement in the transition toward sustainable food development and innovative green strategies are expected in the future.

In vitro digestion characteristics of cereal protein concentrates as assessed using a pepsin-pancreatin digestion model.

An alkaline extraction method has been used in many studies to extract total protein from cereal samples. Wheat bran protein concentrate (WBPC), oat bran protein concentrate (OBPC), and barley protein concentrate (BPC) were prepared by alkaline extraction and isoelectric precipitation to study their functional and nutritional properties. The three protein concentrates were hydrolysed by an in vitro pepsin-pancreatin digestion model. Their digestibility (%) and degree of hydrolysis (DH%) were evaluated, and SDS-PAGE electrophoresis was used to illustrate the protein and peptides patterns. The change of the particle sizes and the release of the essential amino acids was followed during the digestion process. The in vitro digestibility of WBPC, OBPC and BPC was 87.4%, 96.1% and 76.9%, respectively. The DH% of protein concentrates were between 50 and 60%. The change of the particle size distribution values Dv(50) was assumed to be related to protein aggregations during the digestion. The protein fractions were identified and the degradation during the digestion and were analysed by SDS-PAGE; the gels of WBPC and OBPC digestion showed virtually complete degradation whereas the intensive bands of undigested protein were presented for BPC. The generation of the free amino acids and short chain peptides were significantly higher at the end of the intestinal digestion compared to the stages of before and after gastric digestion. Higher content of the deficient amino acids such as lysine and threonine were found comparing to the level of deficient amino acids in cereal grains but does not meet the daily recommended intake.

Non-thermal processing has an impact on the digestibility of the muscle proteins.

Muscle proteins undergo several processes before being ready in a final consumable form. All these processes affect the digestibility of muscle proteins and subsequent release of amino acids and peptides during digestion in the human gut. The present review examines the effects of different processing techniques, such as curing, drying, ripening, comminution, aging, and marination on the digestibility of muscle proteins. The review also examines how the source of muscle proteins alters the gastrointestinal protein digestion. Processing techniques affect the structural and functional properties of muscle proteins and can affect their digestibility negatively or positively depending on the processing conditions. Some of these techniques, such as aging and mincing, can induce favorable changes in muscle proteins, such as partial unfolding or exposure of cleavage sites, and increase susceptibility to hydrolysis by digestive enzymes whereas others, such as drying and marination, can induce unfavorable changes, such as severe cross-linking, protein aggregation, oxidation induced changes or increased disulfide (S-S) bond content, thereby decreasing proteolysis. The underlying mechanisms have been discussed in detail and the conclusions drawn in the light of existing knowledge provide information with potential industrial importance.

Proteomic determinants of uterine receptivity for pregnancy in early and mid-postpartum dairy cows†.

Dairy cow subfertility is a worldwide issue arising from multiple factors. It manifests in >30% early pregnancy losses in seasonal pasture-grazed herds, especially when cows are inseminated in the early post-partum period. Most losses occur before implantation, when embryo growth depends on factors present in maternal tract fluids. Here we examined the proteomic composition of early and mid-postpartum uterine luminal fluid (ULF) in crossbred lactating dairy cows to identify molecular determinants of fertility. We also explored changes in ULF from first to third estrus cycles postpartum in individual cows, linking those changes with divergent embryo development. For this, we flushed uteri of 87 cows at Day 7 of pregnancy at first and third estrus postpartum, recovering, and grading their embryos. Out of 1563 proteins detected, 472 had not been previously reported in this fluid, and 408 were predicted to be actively secreted by bioinformatic analysis. The abundance of 18 proteins with roles in immune regulation and metabolic function (e.g. cystatin B, pyruvate kinase M2) was associated with contrasting embryo quality. Matched-paired pathway analysis indicated that, from first to third estrus postpartum, upregulation of metabolic (e.g. creatine and carbohydrate) and immune (e.g. complement regulation, antiviral defense) processes were related to poorer quality embryos in the third estrus cycle postpartum. Conversely, upregulated signal transduction and protein trafficking appeared related to improved embryo quality in third estrus. These results advance the characterization of the molecular environment of bovine ULF and may aid understanding fertility issues in other mammals, including humans.

Thermal processing implications on the digestibility of meat, fish and seafood proteins.

Thermal processing is an inevitable part of the processing and preparation of meat and meat products for human consumption. However, thermal processing techniques, both commercial and domestic, induce modifications in muscle proteins which can have implications for their digestibility. The nutritive value of muscle proteins is closely related to their digestibility in the gastrointestinal tract and is determined by the end products that it presents in the assimilable form (amino acids and small peptides) for the absorption. The present review examines how different thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect the digestibility of muscle proteins in the gastrointestinal tract. By altering the functional and structural properties of muscle proteins, thermal processing has the potential to influence the digestibility negatively or positively, depending on the processing conditions. Thermal processes such as sous-vide can induce favourable changes, such as partial unfolding or exposure of cleavage sites, in muscle proteins and improve their digestibility whereas processes such as stewing and roasting can induce unfavourable changes, such as protein aggregation, severe oxidation, cross linking or increased disulfide (S-S) content and decrease the susceptibility of proteins during gastrointestinal digestion. The review examines how the underlying mechanisms of different processing conditions can be translated into higher or lower protein digestibility in detail. This review expands the current understanding of muscle protein digestion and generates knowledge that will be indispensable for optimizing the digestibility of thermally processed muscle foods for maximum nutritional benefits and optimal meal planning.

Effect of processing technologies on the digestibility of egg proteins.

Egg and egg products are a rich source of highly bioavailable animal proteins. Several processing technologies can affect the structural and functional properties of these proteins differently and can influence their fate inside the gastrointestinal tract. The present review examines some of the processing technologies for improving egg protein digestibility and discusses how different processing conditions affect the digestibility of egg proteins under gastrointestinal digestion environments. To provide up-to-date information, most of the studies included in this review have been published in the last 5 years on different aspects of egg protein digestibility. Digestibility of egg proteins can be improved by employing some processing technologies that are able to improve the susceptibility of egg proteins to gastrointestinal proteases. Processing technologies, such as pulsed electric field, high-pressure, and ultrasound, can induce conformational and microstructural changes that lead to unfolding of the polypeptides and expose active sites for further interactions. These changes can enhance the accessibility of digestive proteases to cleavage sites. Some of these technologies may inactivate some egg proteins that are enzyme inhibitors, such as trypsin inhibitors. The underlying mechanisms of how different technologies mediate the egg protein digestibility have been discussed in detail. The proteolysis patterns and digestibility of the processed egg proteins are not always predictable and depends on the processing conditions. Empirical input is required to tailor the optimization of processing conditions for favorable effects on protein digestibility.

Amino Acid Sequences of Lactoferrin from Red Deer (Cervus elaphus) Milk and Antimicrobial Activity of Its Derived Peptides Lactoferricin and Lactoferrampin.

Although the bioactivities of bovine lactoferrin have been extensively investigated, little is known about deer milk lactoferrin bioactivity and its amino acid sequence. This research investigated the amino acid sequence of deer lactoferrin and the antimicrobial activities of two lactoferrin-encrypted peptides; lactoferricin (Lfcin) and lactoferrampin (Lfampin). Deer lactoferrin was found to have a molecular weight of 77.1 kDa and an isoelectric point of 7.99, which are similar to that of bovine lactoferrin, 78 kDa and pI 7.9. Deer lactoferrin contains 707 amino acids, one amino acid less than bovine lactoferrin, and has 92% homology with bovine lactoferrin. Deer lactoferricin exhibited strong antimicrobial activity against E. coli American Type Culture Collection (ATCC) 25922 and L. acidophilus ATCC 4356. The antimicrobial activities of deer and bovine Lfcin and Lfampin were compared. Based on MIC, deer Lfcin was found to be a more effective inhibitor of L. acidophilus ATCC 4356 than bovine Lfcin, but bovine Lfcin and Lfampin were more effective against E. coli ATCC 25922 than deer Lfcin and Lfampin. The deer Lfcin sequence differed at seven amino acids from bovine Lfcin and this decreased the net positive charge and increased the hydrophobicity. Deer Lfampin contained two differences in amino acid sequence compared to bovine Lfampin which decreased the net positive charge. These amino acid sequence differences likely account for differences in antibacterial activity. Positive charge and hydrophobic residues provide the amphipathic character of these helical peptides, and are considered important for binding of antimicrobial peptides. In silico modelling of deer Lfcin indicated an identical α-helical structure compared to bovine Lfcin.

Endogenous Proteolytic Systems and Meat Tenderness: Influence of Post-Mortem Storage and Processing.

Meat proteolytic systems play a crucial role in meat tenderisation. Understanding the effects of processing technologies and post-mortem storage conditions on these systems is important due to their crucial role in determining the quality characteristics of meat and meat products. It has recently been proposed that tenderisation occurs due to the synergistic action of numerous endogenous proteolytic systems. There is strong evidence suggesting the importance of µ-calpain during the initial post-mortem aging phase, while m-calpain may have a role during long-term aging. The caspase proteolytic system is also a candidate for cell degradation in the initial stages of conversion of muscle to meat. The role of cathepsins, which are found in the lysosomes, in post-mortem aging is controversial. Lysosomes need to be ruptured, through aging, or other forms of processing to release cathepsins into the cytosol for participation in proteolysis. A combination of optimum storage conditions along with suitable processing may accelerate protease activity within meat, which can potentially lead to improved meat tenderness. Processing technologies such as high pressure, ultrasound, and shockwave processing have been reported to disrupt muscle structure, which can facilitate proteolysis and potentially enhance the aging process. This paper reviews the recent literature on the impacts of processing technologies along with post-mortem storage conditions on the activities of endogenous proteases in meat. The information provided in the review may be helpful in selecting optimum post-mortem meat storage and processing conditions to achieve improved muscle tenderness within shorter aging and cooking times.

Lactoferrin Isolation and Hydrolysis from Red Deer (Cervus elaphus) Milk and the Antibacterial Activity of Deer Lactoferrin and Its Hydrolysates.

Lactoferrin (Lf) and other whey proteins have been isolated from red deer milk for the first time using a three-step anion and cation exchange chromatography protocol. The separated deer Lf was subject to in vitro gastric and duodenal digestions to generate peptides. The purity of the deer Lf and its hydrolysis products were analyzed by SDS-PAGE. The antibacterial activity of the deer Lf and its hydrolysates were investigated and was compared to cow counterpart. Gastric and duodenal digested deer Lf had strong bactericidal activity against E. coli ATCC 25922 with minimum inhibition concentration (MIC) of 280 µM and 402 µM, respectively. These results suggest that deer milk contains bioactive whey proteins and can generate bioactive peptides, which can benefit human health by inhibiting food-borne pathogenic bacteria.

Proteomics and metabolomics in cow fertility: a systematic review.

Cow subfertility is a multi-factorial problem in many countries which is only starting to be unravelled. Molecular biology can provide a substantial source of insight into its causes and potential solutions, particularly through large scale, untargeted omics approaches. In this systematic review, we set out to compile, assess and integrate the latest proteomic and metabolomic research on cow reproduction, specifically that on the female reproductive tract and early embryo. We herein report a general improvement in technical standards throughout the temporal span examined; however, significant methodological limitations are also identified. We propose easily actionable avenues for ameliorating these shortcomings and enhancing the reach of this field. Text mining and pathway analysis corroborate the relevance of proteins and metabolites related to the triad oxidative stress-inflammation-disease on reproductive function. We envisage a breakthrough in cattle reproductive molecular research within the next few years as in vivo sample techniques are improved, omics analysis equipment becomes more affordable and widespread, and software tools for single- and multi-omics data processing are further developed. Additional investigation of the impact of local oxidative stress and inflammation on fertility, both at the local and systemic levels, is key towards realising the full potential of this field.

The application of pulsed electric field as a sodium reducing strategy for meat products.

This study investigated the potential of pulsed electric field (PEF) as a sodium-reduction strategy for processed meat. Beef jerky was used as a model and prepared using different levels of NaCl, viz. 2.0% (control), 1.2% (T1) and 1.2% along with PEF processing (T2). A significant (p < 0.05) effect of PEF was observed on shear force (N) and toughness (N/mm s) of the products, which was also reflected in sensory scores. No effects for PEF were observed on colour, yield (%) and oxidative and microbial stability. PEF-treated samples (T2) had significantly (p < 0.05) lower sodium content than the control, however, the sensory scores were comparable (p > 0.05) with control and >84% of the panellists preferred T2 samples over T1 for saltiness. Results suggest that PEF treatment improved saltiness by influencing the salt diffusion and sodium delivery that led to better perception during chewing. PEF could be a novel method to produce healthier reduced-sodium meat products.

Sous-vide cooking improves the quality and in-vitro digestibility of Semitendinosus from culled dairy cows.

Effect of sous-vide processing was evaluated on in-vitro simulated protein digestion, myofibrillar protein profile, lipid oxidation and physicochemical properties of cold-boned beef Semitendinosus. Sous-vide processed [T1, 60 °C (4.5 h); T2, 60 °C (10 h)] samples along with control beef (cooked at 80 °C until a core temperature of 75 °C was attained) were subjected to in-vitro simulated gastrointestinal protein digestion. Samples collected at 0, 30 and 60 min of gastric digestion and 120 and 180 min of intestinal digestion were analysed for protein profile (SDS-PAGE), protein digestibility (%), soluble protein (%), free amino acid analysis and mineral profile. A significant (P < 0.05) decrease was observed in shear force (N) and cooking loss (%) of sous-vide processed samples in comparison to control whereas a significant (P < 0.05) increase was observed in colour (L*, a*, b*). A significant (P < 0.05) increase was also observed in protein digestibility (%), soluble protein (%) and release of free amino acids and minerals from sous-vide processed samples during in-vitro digestion. By modifying the protein profile of the meat, sous-vide processing had a positive influence on in-vitro digestion kinetics that led to a greater and faster digestion of proteins during simulated digestion.

Pulsed electric field: A new way to improve digestibility of cooked beef.

The effect of pulsed electric field (PEF) on in-vitro simulated gastrointestinal protein digestion of cooked beef Semimembranosus was elucidated. PEF treated (T1, 10 kV, 20 Hz, 20 µs) samples along with control were cooked (core temperature of 75 °C) and subjected to in-vitro simulated gastrointestinal digestion. Samples were analysed for protein digestibility (%), protein profile (SDS-PAGE), soluble protein (%), free amino acid analysis and mineral profile. PEF treatment led to significantly higher (P < .05) values for protein digestibility (%) and soluble protein (%). No significant (P > .05) effect of PEF was recorded on the release of free amino acids and various minerals during gastrointestinal digestion. PEF treatment modified the protein profile of the meat digests and had a positive impact on in-vitro digestion kinetics causing greater and faster digestion of proteins during in-vitro gastrointestinal simulation.

Pulsed electric field: Effect on in-vitro simulated gastrointestinal protein digestion of deer Longissimus dorsi.

The effect of pulsed electric field (PEF) on in-vitro simulated gastrointestinal protein digestion of cold-boned deer Longissimus dorsi was elucidated. PEF treated samples viz. T1 (2.5 kV, 50 Hz) and T2 (10 kV, 90 Hz) along with a control were subjected to in-vitro simulated gastrointestinal protein digestion. Samples were collected after 0, 30, and 60 min of gastric digestion and 120 and 180 min of intestinal digestion. A significant (P < 0.05) increase was observed in the protein digestibility and soluble protein (%) of PEF treated samples, highlighting a positive influence of PEF processing on the digestion process. Higher concentrations of almost all the free amino acids were observed for the PEF treated samples. No significant effect of PEF was observed on the release of various minerals. PEF may be utilized for the development of novel muscle foods with improved protein digestibility.

Pulsed electric field operates enzymatically by causing early activation of calpains in beef during ageing.

A study was conducted to elucidate the impact of pulsed electric field (PEF) on the activity of calpains, proteolytic activity of desmin and troponin-T and physicochemical properties of beef Biceps femoris during ageing. The meat samples (meat blocks) were subjected to two PEF treatments; T1 (5 kV, 90 Hz, 0.38 kV/cm) and T2 (10 kV, 20 Hz, 0.61 kV/cm) and a non-treated control was run in parallel. The samples were vacuum packaged and aged for 1, 7 and 14 days at 4 ±â€¯1 °C. This study reports for the first time the impact of PEF-processing on the calpain activity in beef. Early post-mortem activation of calpain 2 was observed in PEF-treated samples. An increase in the calpain activity and proteolysis of desmin and troponin-T was observed. No significant effect of PEF was observed on the shear force of tough muscles from culled dairy animals during the entire ageing period.

Current and future prospects for the use of pulsed electric field in the meat industry.

Pulsed electric field (PEF) is a novel non-thermal technology that has recently attracted the attention of meat scientists and technologists due to its ability to modify membrane structure and enhance mass transfer. Several studies have confirmed the potential of pulsed electric field for improving meat tenderness in both pre-rigor and post-rigor muscles during aging. However, there is a high degree of variability between studies and the underlying mechanisms are not clearly understood. While some studies have suggested physical disruption as the main cause of PEF induced tenderness, enzymatic nature of the tenderization seems to be the most plausible mechanism. Several studies have suggested the potential of PEF to mediate the tenderization process due to its membrane altering properties causing early release of calcium ions and early activation of the calpain proteases. However, experimental research is yet to confirm this postulation. Recent studies have also reported increased post-mortem proteolysis in PEF treated muscles during aging. PEF has also been reported to accelerate curing, enhance drying and reduce the numbers of both pathogens and spoilage organisms in meat, although that demands intense processing conditions. While tenderization, meat safety and accelerated curing appears to be the areas where PEF could provide attractive options in meat processing, further research is required before the application of PEF becomes a commercial reality in the meat industry. It needs to deal with carcasses which vary biochemically and in composition (muscle, fat, and bones). This review critically evaluates the published reports on the topic with the aim of reaching a clear understanding of the possible applications of PEF in the meat sector in addition to providing some insight on critical issues that need to be addressed for the technology to be a practical option for the meat industry.

Obesity and neurological disorders: Dietary perspective of a global menace.

Obesity is considered a major public health concern throughout the world among children, adolescents, as well as adults and several therapeutic, preventive and dietary interventions are available. In addition to life style changes and medical interventions, significant milestones have been achieved in the past decades in the development of several functional foods and dietary regimens to reduce this menace. Being a multifactorial phenomenon and related to increased fat mass that adversely affects health, obesity has been associated with the development of several other co-morbidities. A great body of research and strong scientific evidence identifies obesity as an important risk factor for onset and progression of several neurological disorders. Obesity induced dyslipidaemia, metabolic dysfunction, and inflammation are attributable to the development of a variety of effects on central nervous system (CNS). Evidence suggests that neurological diseases such as Parkinson's disease and Alzheimer's disease could be initiated by various metabolic changes, related to CNS damage, caused by obesity. These metabolic changes could alter the synaptic plasticity of the neurons and lead to neural death, affecting the normal physiology of CNS. Dietary intervention in combination with exercise can affect the molecular events involved in energy metabolism and synaptic plasticity and are considered effective non-invasive strategy to counteract cognitive and neurological disorders. The present review gives an overview of the obesity and related neurological disorders and the possible dietary interventions.

Tripeptide analogues of MG132 as protease inhibitors.

The 26S proteasome and calpain are linked to a number of important human diseases. Here, we report a series of analogues of the prototypical tripeptide aldehyde inhibitor MG132 that show a unique combination of high activity and selectivity for calpains over proteasome. Tripeptide aldehydes (1-3) with an aromatic P3 substituent show enhanced activity and selectivity against ovine calpain 2 relative to chymotrypsin-like activity of proteasome. Docking studies reveal the key contacts between inhibitors and calpain to confirm the importance of the S3 pocket with respect to selectivity between calpains 1 and 2 and the proteasome.