Use of Cyanobacterium Spirulina (Arthrospira platensis) in Buffalo Feeding: Effect on Mozzarella Cheese Quality.

The high demand for PDO buffalo mozzarella cheese is leading to the use of new strategies for feeding supplementation. Spirulina is acknowledged as a valuable source of protein with antioxidant and immune-modulatory effects in humans and animals. This investigation aimed to examine the effect of Spirulina integration in buffalo diets on mozzarella cheese quality, sensory profile, consumer acceptability, and willingness to pay (WTP). The trial was carried out on two groups of 12 buffaloes that differed in Spirulina integration: 50 g/head/d before calving (1 month) and 100 g/head/d after calving (2 months). Both the bulk milk and mozzarella cheese samples from the two groups did not differ in chemical composition. However, Spirulina inclusion influenced the sensory quality of mozzarella cheese, which resulted it being externally brighter, with a higher butter odour and whey flavour and greater sweetness, bitterness, juiciness, tenderness, oiliness, and buttermilk release than the control. The consumer test showed that information about Spirulina affected consumer liking, causing them to be in favour of the Spirulina group, leading to a higher price for it. In conclusion, Spirulina inclusion in buffalo diets affected the sensory quality of mozzarella cheese. The provision of product information to consumers can be a crucial factor in determining their liking and WTP.

Effects of the Aging Period and Method on the Physicochemical, Microbiological and Rheological Characteristics of Two Cuts of Charolais Beef.

Wet-aging (WA) and dry-aging (DA) methods are usually used in the beef industry to satisfy the consumers' tastes; however, these methods are not suitable for all anatomical cuts. In this study, WA and DA were applied to improve the quality of two cuts of Charolais beef (Longissimus dorsi and Semitendinosus). For 60 days (i.e., 2 days, 15 days, 30 days and 60 days of sampling), a physicochemical, rheological, and microbiological analysis were performed at WA (vacuum packed; temperature of 4 ± 1 °C) and at DA (air velocity of 0.5 m/s; temperature of 1 ± 1 °C; relative humidity of 78 ± 10%) conditions. The results showed that the aging method influenced the aging loss (higher in the DA), cooking loss (higher in the WA), malondialdehyde concentration (higher in the DA) and fatty acid profile (few changes). No differences in the drip loss and color were observed, which decreased after 30 days of aging. The WBSF and TPA test values changed with increasing an aging time showing that the aging improved the tenderness of meat regardless of the aging method. Moreover, the aging method does not influence the microbiological profile. In conclusion, both WA and DA enhanced the quality of the different beef cuts, suggesting that an optimal method-time and aging combination could be pursued to reach the consumers' preferences.

A Morphological and Ultrastructural Study of the Anterior Digestive Tract of Adult Nile Tilapia Oreochromis niloticus.

Among the most-used fish species in aquaculture is the Nile tilapia, due to its rapid growth rate and its adaptation to a wide range of farming conditions. A careful description of the morphology of the digestive tract, particularly the esophagus and stomach, allows a better understanding of the relationship between structure and function. Combining scanning and light microscopy we highlighted the presence of five different zones in the stomach (1: esophagus-gastric lumen passage; 2: descending glandular portion; 3: fundic portion; 4: ascending glandular portion; 5: gastric-pyloric transition portion). Histochemical investigation showed a secretion of carboxylates mucopolysaccharides along the esophagus and sulphated complex carbohydrates in the stomach. These results suggest that mucins play a protective role of the epithelial lining, which is essential for a correct digestive process. Finally, the characterization of the main cellular structures may be inspiring for more advanced studies aiming to decipher the role of specific molecules, such as neuropeptides, involved in the physiological digestive process.

Effects of Feeding and Maturation System on Qualitative Characteristics of Buffalo Meat (Bubalus bubalis).

We aimed to evaluate the effects of post dry ageing (PDA) period on meat colour and rheological characteristics in 16 buffalo bulls fed two different diets: with (FRS) or without (CTL) rye grass. Animals were randomly divided into two feeding groups and slaughtered at 540 ± 4.7 and 533 ± 7.0 kg of live body weight, respectively, for the CTL and FRS group. After five days post-mortem ageing (T0), Semitendinosus muscle (ST) and Longissimus muscle (LD) underwent a prolonged maturation process in a controlled meat chamber for 30 days (ST) and until 60 days (LD). After 30 days (T1), significant changes (p < 0.01) in meat colour (ΔE) in both muscles of the FRS group was recorded, while no significant change was observed in CTL group. The FRS diet had a positive effect on textural properties of ST muscle compared to CTL diet, as well as hardness, chewiness and gumminess. All qualitative characteristics improved in the first period of PDA but, whereas LD showed to keep improving, extending the post-ageing period by further 30 days, the ST becomes un-processable at 60 days. In conclusion, a combined used of fresh feeding and PDA period could enhance both tenderness and colour in animal fed FSR.

High Fiber Cakes from Mediterranean Multipurpose Oilseeds as Protein Sources for Ruminants.

Fifteen oilseed cakes from sunflower, pomegranate, cardoon, tobacco and hemp were characterized with regard to chemical composition, Cornell Net Carbohydrate and Protein System (CNCPS) fractionation, in vitro digestibility of dry matter, neutral detergent fiber, and crude protein. All the cakes presented low moisture, rather variable ether extract contents and medium to high levels of crude protein and neutral detergent fiber. The cakes significantly differed in terms of CNCPS partitioning and in vitro digestibility. Tobacco and hemp cakes presented high contents of slow degradable fractions of crude protein and carbohydrate joined to good post-ruminal protein digestibility. Cardoon cakes presented the highest rumen protein degradability. Based on crude protein content and intestinal digestibility of rumen undegraded protein, cakes of tobacco and hemp showed the better potential as alternative protein supplements for ruminants, while pomegranate appears to be the least suitable for ruminant feeding.

Microbiological, rheological and physical-chemical characteristics of bovine meat subjected to a prolonged ageing period.

The aim of this study was to evaluate the effects of a long ageing period on the microbiological, rheological and physicalchemical characteristics of bovine beef. For the trial n. 3 Marchigiana bovine breed (live weight of 760 kg approximately), slaughtered at 34 months were chosen and the loin muscles were undergone to a prolonged ageing process. The analytical determinations performed were: pH and aw values, texture profile analysis, Warner-Bratzler shear force, colour (CIE L*a*b*), centesimal analysis, total bacterial count, Enterobacteriaceae, Listeria monocytogenes, yeasts and moulds. The results indicate that extended ageing has a negative effect on weight loss but, by the means of the standardization of dry aging parameters, reduce lipid oxidation and improve tenderness.

Effects of dietary supplementation with polyphenols on meat quality in Saanen goat kids.

BACKGROUND: Diet supplementation with polyphenols is a novel strategy to improve meat quality in livestock, by preventing oxidative deterioration of lipids and protein. Polyphenols have beneficial effects on both human and animal health and can be obtained from several sources, such as olive mill wastewaters (OMWW). These are severe environmental pollutants and therefore may be recycled and utilized in other sectors. The aim of this study was to evaluate growth performance, meat characteristics, fatty acid composition, antioxidant status, different forms of myoglobin and malondialdehyde formation in kids who received a diet supplemented with polyphenols obtained from OMWW. Weaned goat kids (n = 18) were divided into two homogenous groups: control (C) group (n = 9) received a fattening standard diet while the other group (n = 9) received the same diet, supplemented with 3.2 mg/day of polyphenols powder extract (PE group). Average daily gain (ADG) was calculated 10 days apart throughout the study. After 78 days, the kids were slaughtered and pH and carcass yield were evaluated. Longissimus thoracis et lumborum muscle was collected and utilized for chemical analysis, meat quality evaluation and oxidative stability. RESULTS: No differences were recorded in ADG, carcass weight, pH and dressing between the two groups. Furthermore a similar meat proximate composition, texture and color was observed. Dietary polyphenols supplementation significantly (P < 0.01) decreased short chains (

Sequence Analysis, Kinetic Constants, and Anion Inhibition Profile of the Nacrein-Like Protein (CgiNAP2X1) from the Pacific Oyster Magallana gigas (Ex-Crassostrea gigas).

The carbonic anhydrase (CA, EC 4.2.1.1) superfamily of metalloenzymes catalyzes the hydration of carbon dioxide to bicarbonate and protons. The catalytically active form of these enzymes incorporates a metal hydroxide derivative, the formation of which is the rate-determining step of catalytic reaction, being affected by the transfer of a proton from a metal-coordinated water molecule to the environment. Here, we report the cloning, expression, and purification of a particular CA, i.e., nacrein-like protein encoded in the genome of the Pacific oyster Magallana gigas (previously known as Crassostrea gigas). Furthermore, the amino acid sequence, kinetic constants, and anion inhibition profile of the recombinant enzyme were investigated for the first time. The new protein, CgiNAP2X1, is highly effective as catalyst for the CO2 hydration reaction, based on the measured kinetic parameters, i.e., kcat = 1.0 × 106 s-1 and kcat/KM = 1.2 × 108 M-1·s-1. CgiNAP2X1 has a putative signal peptide, which probably allows an extracellular localization of the protein. The inhibition data demonstrated that the best anion inhibitors of CgiNAP2X1 were diethyldithiocarbamate, sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid, which showed a micromolar affinity for this enzyme, with KIs in the range of 76-87 µM. These studies may add new information on the physiological role of the molluskan CAs in the biocalcification processes.

Cloning, expression and purification of the α-carbonic anhydrase from the mantle of the Mediterranean mussel, Mytilus galloprovincialis.

We cloned, expressed, purified, and determined the kinetic constants of the recombinant α-carbonic anhydrase (rec-MgaCA) identified in the mantle tissue of the bivalve Mediterranean mussel, Mytilus galloprovincialis. In metazoans, the α-CA family is largely represented and plays a pivotal role in the deposition of calcium carbonate biominerals. Our results demonstrated that rec-MgaCA was a monomer with an apparent molecular weight of about 32 kDa. Moreover, the determined kinetic parameters for the CO2 hydration reaction were kcat = 4.2 × 105 s-1 and kcat/Km of 3.5 × 107 M-1 ×s-1. Curiously, the rec-MgaCA showed a very similar kinetic and acetazolamide inhibition features when compared to those of the native enzyme (MgaCA), which has a molecular weight of 50 kDa. Analysing the SDS-PAGE, the protonography, and the kinetic analysis performed on the native and recombinant enzyme, we hypothesised that probably the native MgaCA is a multidomain protein with a single CA domain at the N-terminus of the protein. This hypothesis is corroborated by the existence in mollusks of multidomain proteins with a hydratase activity. Among these proteins, nacrein is an example of α-CA multidomain proteins characterised by a single CA domain at the N-terminus part of the entire protein.

Production and covalent immobilisation of the recombinant bacterial carbonic anhydrase (SspCA) onto magnetic nanoparticles.

Carbonic anhydrases (CAs; EC 4.2.1.1) are metalloenzymes with a pivotal potential role in the biomimetic CO2 capture process (CCP) because these biocatalysts catalyse the simple but physiologically crucial reaction of carbon dioxide hydration to bicarbonate and protons in all life kingdoms. The CAs are among the fastest known enzymes, with kcat values of up to 106 s-1 for some members of the superfamily, providing thus advantages when compared with other CCP methods, as they are specific for CO2. Thermostable CAs might be used in CCP technology because of their ability to perform catalysis in operatively hard conditions, typical of the industrial processes. Moreover, the improvement of the enzyme stability and its reuse are important for lowering the costs. These aspects can be overcome by immobilising the enzyme on a specific support. We report in this article that the recombinant thermostable SspCA (α-CA) from the thermophilic bacterium Sulfurihydrogenibium yellowstonense can been heterologously produced by a high-density fermentation of Escherichia coli cultures, and covalently immobilised onto the surface of magnetic Fe3O4 nanoparticles (MNP) via carbodiimide activation reactions. Our results demonstrate that using a benchtop bioprocess station and strategies for optimising the bacterial growth, it is possible to produce at low cost a large amount SspCA. Furthermore, the enzyme stability and storage greatly increased through the immobilisation, as SspCA bound to MNP could be recovered from the reaction mixture by simply using a magnet or an electromagnetic field, due to the strong ferromagnetic properties of Fe3O4.

Biochemical characterization of the native α-carbonic anhydrase purified from the mantle of the Mediterranean mussel, Mytilus galloprovincialis.

A α-carbonic anhydrase (CA, EC 4.2.1.1) has been purified and characterized biochemically from the mollusk Mytilus galloprovincialis. As in most mollusks, this α-CA is involved in the biomineralization processes leading to the precipitation of calcium carbonate in the mussel shell. The new enzyme had a molecular weight of 50 kDa, which is roughly two times higher than that of a monomeric α-class enzyme. Thus, Mytilus galloprovincialis α-CA is either a dimer, or similar to the Tridacna gigas CA described earlier, may have two different CA domains in its polypeptide chain. The Mytilus galloprovincialis α-CA sequence contained the three His residues acting as zinc ligands and the gate-keeper residues present in all α-CAs (Glu106-Thr199), but had a Lys in position 64 and not a His as proton shuttling residue, being thus similar to the human isoform hCA III. This probably explains the relatively low catalytic activity of Mytilus galloprovincialis α-CA, with the following kinetic parameters for the CO2 hydration reaction: kcat = 4.1 × 105 s-1 and kcat/Km of 3.6 × 107 M-1 × s-1. The enzyme activity was poorly inhibited by the sulfonamide acetazolamide, with a KI of 380 nM. This study is one of the few describing in detail the biochemical characterization of a molluskan CA and may be useful for understanding in detail the phylogeny of these enzymes, their role in biocalcification processes and their potential use in the biomimetic capture of the CO2.