5,590 research outputs found

    Effect of different oleogelators on lipolysis and curcuminoid bioaccessibility upon in vitro digestion of sunflower oil oleogels

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    Sunflower oil enriched with curcuminoid compounds (CUs) was gelled by adding 5% (w/w) saturated monoglycerides (MG), rice bran waxes (RW) or a mixture of \u3b2-sitosterol and \u3b3-oryzanol (PS). The resulting oleogels differed for rheological properties and firmness due to the difference in gel network structure. PS oleogel was the firmest sample followed by RW and MG ones. Upon in vitro digestion, fatty acid release as a function of digestion time was greatly affected by oleogel structure: the extent of lipolysis decreased as oleogel strength increased (PS < RW < MG). On the other hand, the nature of the oleogelator affected CUs bioaccessibility, which was lower in oleogels containing crystalline particles (MG and RW). These findings appear interesting in the attempt to develop oleogels able to control lipid digestion as well as to deliver bioactive molecules in food systems

    Modulation of Extra Virgin Olive Oil Digestibility through Oleogelation

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    Background. Extra virgin olive oil (EVOO) represents a key player in the Mediterranean diet for its health-promoting capacity. Although its use as a functional ingredient would be particularly interesting, the direct addition of EVOO to food is challenging due to its liquid state. EVOO conversion into a solid-like material through by oleogelation could enlarge its possible applications. Methods. EVOO was gelled by adding 10% (w/w) of saturated monoglycerides (MG), rice bran waxes (RW), sunflower waxes (SW) or a β-sitosterol/γ-oryzanol mixture (PS). Oleogels were characterised for their structure and subjected to static in vitro digestion. The fatty acid release and destructuring behavior were assessed. Results. The resulting oleogels differed for rheological properties and firmness due to the differences in gel network structure. PS oleogel was the firmest sample followed by SW, RW and MG ones. During in vitro digestion, the fatty acid release was significantly lower for all oleogels compared to unstructured oil. The different network provided by the four oleogelators not only influenced FA release, but also the intestinal micellar size. Conclusion. Acquired results could open new horizons for EVOO application through oleogelation to obtain novel EVOO-based fat replacers and better deliver the EVOO health functionalities

    Effects of long term feeding diets differing in protein source and pre-slaughter starvation on biometry, qualitative traits and liver IGF-I expression in large rainbow trout

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    The effects of feeding two complete extruded diets differing in protein source (fish meal-FM vs. vegetable proteins-VP) over 30 weeks and subsequent 30 days of starvation on biometry, fillet composition and liver IGF-I mRNA were studied in large rainbow trout. At the end of the feeding period, the dietary protein source little affected major biometry traits, dressing out yields and overall adiposity (P>0.05) but fish given the VP diet resulted in higher content of PUFA n-6 fatty acids in mus- cle (0.46 vs. 0.22 g/100g fillet, P0.05) and of all fatty acids in fillet (P<0.05), except DHA. Liver IGF-I mRNA content was little affected by the test diet and starvation

    Growth performance of sea bass fed increasing levels of pea-wheat protein in diets varying in fish meal quality

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    A 11-week trial was carried out to compare the growth performance of sea bass (D. labrax) fed six isonitrogenous isocaloric diets where protein from two fish meals of different nutritive value was replaced with graded levels (0, 50 or 75%) of a mixture made up by a pea protein concentrate and wheat gluten. Fish meal quality did not affect (P>0.05) weight gain or feed efficiency in fish fed graded levels of plant protein in the diet. Feed intake decreased (P<0.05) as the level of plant protein was increased in the diet but this did not led to impaired growth or feed conversion rate. Protein efficiency and retention were equally improved (P<0.05) only with diets where a poor quality fish meal was substituted by protein rich-plant ingredients. Calculations based on the mass balance of nutrients of sea bass proven the inclusion of a mixture of highly purified plant-protein derivatives in complete diets for the sea bass, to be beneficial in reducing pollution load

    Rheological investigation and simulation of a debris-flow event in the Fella watershed

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    Abstract. To set an approach for the future territorial planning, the Geological Survey of Friuli Venezia Giulia Region, through the researchers of Trieste University, started a program of debris-flow risk analysis using Flo-2D software as tool to delimit the hazardous areas. In the present paper, as a case study, a debris flow, called Fella sx, occurring in a torrent catchment was analyzed. The choice was due to the abundance of information about past events, inundated areas, rain fall, geology and to its representativeness. An initial back-analysis investigation identified a couple of representative rheological parameters. Riverbed samples were collected, sieve analyses were performed and rheological tests were carried out on the fraction finer than 0.063 mm using a rotationally controlled stress rehometer equipped with the serrated parallel plate geometry. The shear dependent behaviour was examined at different concentrations ranging from 33 to 48%, by weight. Viscosity data treatment was performed to determine the most suitable rheological model to provide the best approximation of the debris-flow behaviour. The rheological parameters, derived from experimental data, were used and compared with those obtained through the back-analysis and with the real inundated area. Data obtained through rheological analysis are useful in constructing scenarios of future events where no data for back-analysis are available

    Effect of different biopolymer-based structured systems on the survival of probiotic strains during storage and in vitro digestion

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    BACKGROUND: This study aimed to evaluate the protective effect of different biopolymer systems on the viability of two probiotics (Lactobacillus rhamnosus and Streptococcus thermophilus) during storage and in vitro digestion. Methylcellulose (MC), sodium alginate (SA), and whey protein (WP)-based structures were designed and characterized in terms of pH, rheological properties, and visual appearance. RESULTS: The results highlighted that the WP-system ensured probiotic protection during both storage and in vitro digestion. This result was attributed to a combined effect of the physical barrier offered by the protein gel network and whey proteins as a nutrient for microbes. On the other hand, surprisingly, the viscous methylcellulose-based system was able to guarantee good microbial viability during storage. However, this was not confirmed during in vitro digestion. The opposite results were obtained for sodium alginate beads. CONCLUSION: The results suggest that the capacity of a polymeric structure to protect probiotic bacteria is a combination of structural organization and system formulation. \ua9 2020 Society of Chemical Industry

    Modeling the effect of the oxidation status of the ingredient oil on stability and shelf life of low-moisture bakery products: The case study of crackers

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    In packed low-moisture foods such as crackers, oxidation is generally the main cause of quality depletion during storage. It is commonly believed, but scarcely investigated, that product shelf life depends on the oxidative status of the lipid ingredients. In this study, the influence of oxidation degree of the ingredient sunflower oil on cracker oxidative stability and hence shelf life was investigated. To this aim, oil with increasing peroxide values (PVs) (5, 11, and 25 mEqO2/kgoil) was used to prepare crackers. Just after production, crackers presented similar peroxide and rancid odor intensity, probably due to the interactive pathways of oxidative and Maillard reactions. Crackers were packed and analyzed for PV and rancid odor during storage at 20, 40, and 60 \u25e6C. Rancid odor well discriminated cracker oxidative status. Relevant oxidation rates were used to develop a shelf life predictive model based on the peroxide value of the ingredient oil. It was estimated that an oil PV from 5 to 15 mEqO2/kgoil shortens cracker Shelf Life (SL) by 50%, independently of storage temperature. These results demonstrate the critical impact of ingredient quality on product performance on the market

    PRINCIPLES OF APPLIED BIOMECHANICS ON THE RACE WALKERS: IMPROVEMENT IN PERFORMANCE WITH A PLANTAR ORTHOSIS

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    When race walking it is essential to attain and maintain for a period of time the maximal speed with minimal expenditure of energy, in observance of the prescribed standards. To achieve this end, optimizing the physical carriage is indispensable. This may be done in two ways: I) by reducing those force component hat ace employed along directions of application that do no concur with the sense of progression, since they interfere with and disperse part of the energy; and 2) by increasing the vectorial components that have the same direction as the forward movement. The aim of our work was to verify the modifications that are induced by the use of plantar orthoses , as reflected by parameters of biomechanical performance on the race walker: Under standard reference conditions, we studied the kinematics and ground reaction of 10 highly-trained Athletes. With reference to report that confirmed previous study by us and other authors, we verified the modifications induced by the applications of special dynamic plantar orthoses. The ground reaction appeared to be optimized by the use of these orthoses through the following mechanisms: 1) a diminution of the sagittal force components that are opposed to the direction of movemen6 2) a diminution of the transverse edgewise components that are not useful to the progression, and 3) an increase in the reclamation of useful elastic energy stored by the functional unit, the 'musculo-skeletal footwear system”

    Welfare and quality of farmed trout fed high plant protein diets. 1 Growth performance and quality traits

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    AbstractThis study was performed to evaluate the effects of high levels of inclusion of plant protein sources to replace fish meal in rainbow trout (O. mykiss) diets on growth performance and quality characteristics. Two isoproteic (44.8%) and isolipidic (19.6%) extruded diets were fed to eight groups of trout (IBW 106.6g) for 103 days. Diet FM, containing only fish meal as protein source, was used as control treatment and compared to diet PV80, where a plant protein mix (pea protein concentrate and wheat gluten) was included to replace 80% of fish meal protein. Growth performance (FBW: 318.5g; SGR: 1.06%) and feed to gain ratio (0.79) of the fish were not affected by dietary treatment (p>0.05). Dry matter and protein ADCs, measured in vivo after stripping, resulted higher in fish fed the high vegetable protein diet relative to the fish meal one (p<0.05). Trout fed diet PV80 were characterised by higher agility index (2.02 vs 1.72, p<0.05), carcass yield (91.95 vs 91.18%, p<0.05), lower hepatosomatic inde..

    growth performance and stress response of common sole subjected to varying stocking densities and rearing temperatures

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    AbstractEarlier short-term studies have shown productivity of intensively farmed common sole (S. solea) to be closely dependent on rearing density. Irrespective of fish size, elevating crowding conditions led to declining growth rates while the effect of density on mortality remains controversial. To what extent water temperature could affect productivity of growing sole subjected to varying crowding conditions, warrants investigation as very few studies have tried to quantify the effects of this fundamental rearing parameter on growth and survival in this fish species. This is particularly crucial for developing suitable farming protocols in Italy, where common sole may experience a broad range of water temperatures throughout the rearing cycle. The aim of this study was to evaluate productivity and blood cortisol level as a measure of stress response, in growing sole subjected to different stocking densities and temperature conditions. Six hundred juveniles (ind. weight 21.8±1.5g) were randomly allotted..
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