Development of a prebiotic strawberry preparation for the dairy industry

Background. Food industry has been pressed to develop products with reduced sugar and caloric value, with the challenge of keeping rheological and sensory characteristics. Herein we developed a functional strawberry preparation for the dairy industry, by in-situ enzymatic conversion of sucrose into prebiotic fructo-oligosaccharides (FOS). Methodology. Two enzymatic complexes (Pectinex®Ultra SP-L and Viscozyme®L) were applied in the preparation. Operational parameters were optimized to maximize FOS yield: temperature, pH, enzyme:substrate ratio (E/S). Rheological, physicochemical and functional properties (INFOGEST gastrointestinal digestion protocol) were evaluated. Results. At optimal conditions (60 , pH 5.0), Pectinex produced 265±3 g·L1 FOS, yielding 0.581±0.006 gFOS·gin.GF1 after 7 h reaction (E/S:1/40); and Viscozyme produced 295±1 g·L1 FOS, yielding 0.664±0.004 gFOS·gin.GF1 after 5 h (E/S:1/30), both resulting in preparations with 50% (w/w) FOS. The caloric value was reduced 24%, including 80% sucrose reduction. Differences in colour, water activity and ºBrix were not relevant, while consistency and viscosity decreased 70% and pH increased from 4.4 to 4.7. FOS showed resistance to gastrointestinal digestion; only kestose was slightly hydrolysed at intestinal phase. Conclusions. A prebiotic strawberry preparation was successfully produced at lab scale, by in-situ enzymatic conversion of caloric into functional sugars. Next, the process will be scaled-up at industrial level. Background. Food industry has been pressed to develop products with reduced sugar and caloric value, with the challenge of keeping rheological and sensory characteristics. Herein we developed a functional strawberry preparation for the dairy industry, by in-situ enzymatic conversion of sucrose into prebiotic fructo-oligosaccharides (FOS). Methodology. Two enzymatic complexes (Pectinex®Ultra SP-L and Viscozyme®L) were applied in the preparation. Operational parameters were optimized to maximize FOS yield: temperature, pH, enzyme:substrate ratio (E/S). Rheological, physicochemical and functional properties (INFOGEST gastrointestinal digestion protocol) were evaluated. Results. At optimal conditions (60 , pH 5.0), Pectinex produced 265±3 g/L FOS, yielding 0.581±0.006 g(FOS)/g(initial.GF) after 7 h reaction (E/S:1/40); and Viscozyme produced 295±1 g/L FOS, yielding 0.664±0.004 g(FOS)/g(initial.GF) after 5 h (E/S:1/30), both resulting in preparations with 50% (w/w) FOS. The caloric value was reduced 24%, including 80% sucrose reduction. Differences in colour, water activity and ºBrix were not relevant, while consistency and viscosity decreased 70% and pH increased from 4.4 to 4.7. FOS showed resistance to gastrointestinal digestion; only kestose was slightly hydrolysed at intestinal phase. Conclusions. A prebiotic strawberry preparation was successfully produced at lab scale, by in-situ enzymatic conversion of caloric into functional sugars. Next, the process will be scaled-up at industrial level.info:eu-repo/semantics/publishedVersio

Development of a functional prebiotic strawberry preparation by in situ enzymatic conversion of sucrose into fructo-oligosaccharides

Food industry has been pressed to develop products with reduced sugar and low caloric value, while maintaining unchanged their rheological and physicochemical properties. The development of a strawberry preparation for the dairy industry, with prebiotic functionality, was herein investigated by in situ conversion of its intrinsic sucrose content into prebiotic fructo-oligosaccharides (FOS). Two commercial enzymatic complexes, Viscozyme® L and Pectinex® Ultra SP-L, were evaluated for the synthesis of FOS. Operational parameters such as temperature, pH, and enzyme:substrate ratio (E:S) were optimized to maximize FOS yield. The rheological and physicochemical properties of the obtained strawberry preparation were evaluated. For functional analysis, the resistance of FOS to the harsh conditions of the gastro-intestinal digestion was evaluated by applying the standardized INFOGEST static protocol. At optimal conditions (60 , pH 5.0), Pectinex® produced 265±3 g·L1 FOS, yielding 0.57±0.01 gFOS·gin.GF1 after 7hours reaction (E:S:1:40); and Viscozyme® produced 295±1 g·L1 FOS, yielding 0.66±0.00 gFOS·gin.GF1 after 5 hours (E:S:1:30). The obtained strawberry preparations contained more than 50%(w/w) prebiotic FOS incorporated (DP 35), with 80 % reduction of its sucrose content. The caloric value was therefore reduced by 2631%. FOS showed resistance to gastrointestinal digestion being only slightly hydrolysed (< 10%). Fructo-furanosylnystose was not digested at any phase of the digestion. Although the physicochemical properties of the prebiotic preparations were different from the original one, parameters such as the lower °Brix, water activity, consistency and viscosity, and its different color, may be easily adjusted. Results indicate that in situ synthesis strategies are efficient alternatives in the manufacture of reduced sugar and low-caloric food products with prebiotic potential.This work was supported by the FCT under the scope of the strategic funding of UIDB/04469/2020 unit, by National Funds through the FCT under the project cLabel+ (POCI01-0247-FEDER-046080) co-financed by Compete 2020, Lisbon 2020, Portugal 2020 and the European Union, through the European Regional Development Fund (ERDF) and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. Daniela A. Gonçalves acknowledge the Portuguese Foundation for Science and Technology (FCT) for the PhD Grant (2022.11590.BD). The authors acknowledge Frulact SA for all support concerning the materials and information related to the industry sector.info:eu-repo/semantics/publishedVersio

In-situ enzymatic conversion of sucrose into prebiotic fructooligosaccharides for the development of a functional strawberry preparation

The increased search for reduced-sugar and healthier food products has driven the growth of the functional food market [1]. This opened space for the development of novel functional products. Frulact SA, a partner in this project, is specialized in the development and production of fruit-based preparations, which are mainly utilized in the dairy industry for incorporation in flavored yogurts. Its market is expected to increase at a compound annual growth rate of 6.1% until 2030 [2]. However, despite being rich in nutrients, these preparations have a high amount of caloric added sugar. To reduce this sugar in a strawberry preparation, we herein propose an in-situ enzymatic conversion of its sucrose content into prebiotic fructooligosaccharides (FOS) [3,4]. Two commercial enzymatic complexes were evaluated for the in-situ synthesis of FOS. At optimal conditions (60 °C and pH 5.0), Pectinex® Ultra SP-L yielded 0.57 ± 0.01 gFOS/gini.sucrose after 7 h reaction and Viscozyme® L, 0.66 ± 0.00 gFOS/gini.sucrose after 5 h. The resultant strawberry preparations contained more than 50 % (w/w) of FOS in total carbohydrates. Also, more than 80 % of the original sucrose content was reduced, diminishing its caloric value by 31 %. The data show that consumption of dairy products containing 10 % of the developed prebiotic preparation would result in the ingestion of >2.5 grams of FOS per 100 mL of product. The prebiotic preparation showed also to resist the harsh conditions of the gastrointestinal tract since more than 90 % of FOS were not hydrolyzed during digestion. The conversion of sucrose into FOS changed some physicochemical and textural attributes of the original product (i.e., sweetness, color, viscosity, consistency), yet those can be easily adjusted. The in-situ technological approach here developed shown great potential as an innovative strategy for the development of low-sugar and low-calorie prebiotic food.This work was supported by the FCT under the scope of the strategic funding of UIDB/04469/2020 unit, by National Funds through the FCT under the project cLabel+ (POCI-679 01-0247- FEDER-046080) co-financed by Compete 2020, Lisbon 2020, Portugal 2020 and the European Union, through the European Regional Development Fund (ERDF) and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. Daniela A. Gonçalves acknowledge the Portuguese Foundation for Science and Technology (FCT) for the PhD Grant (2022.11590.BD).info:eu-repo/semantics/publishedVersio

Valorization of toxic cyanobacteria biomass - disruption efficiency assessment and consequent bioproduct availability using different disruption techniques

The worldwide occurrence of hepatotoxic cyanobacterium Microcystis aeruginosa and accumulation of its toxin microcystin-LR, have been responsible for several human deaths and animal intoxication incidents. In recognition to its toxicity, the World Health Organization and several national governments established guideline values for this toxin in water, which gave rise to an increasing demand for microcystin′s analytical standards. These standards might be useful either as laboratory standards to apply in human and environmental risk assessment or as tools for molecular and cell biology studies. However, their availability is still limited due to constraints found in production and purification processes, which inflate the final price to values as high as 28000 €/mg. As an example of the increasing interest observed over the last years, U.S. Environmental Protection Agency has recently announced that cyanotoxins became part of its list of substances to be studied as a precursor to regulatory action between 2018 and 2020. Consequently, the optimization of this cyanobacterium cultivation and toxin purification techniques is needed to decrease the production cost of such high added-value product. In biotechnological industrial scale processes, the costs associated with downstream processing often represent more than 60 % of the overall expenses. The aim of this work is therefore to provide an insight regarding the development of a costeffective process for obtaining high-quality and affordable microcystin-LR by evaluating the efficiency of three different methodologies (microwave, freeze-thaw cycles and bead mill) on the disruption of M. aeruginosa and consequent availability of bioproducts. For that purpose, several parameters including time, power, and temperature were tested. The best conditions determined for each extraction method were the following: i) 1.5 minutes at 800 W (microwave), ii) three 12- hour cycles at -20 ºC (freeze-thaw cycles), and iii) 7 minutes using 20 % (v/v) of glass beads (bead mill). According to cell counting and intracellular organic matter release determining techniques, freeze-thaw cycles have shown to be the best disruption method presenting an overall efficiency around 97 %

Body fat assessment in international elite soccer referees

Soccer referees are a specific group in the sports population that are receiving increasing attention from sports scientists. A lower fat mass percentage (FM%) is a useful parameter to monitor fitness status and aerobic performance, while being able to evaluate it with a simple and quick field-based method can allow a regular assessment. The aim of this study was to provide a specific profile for referees based on morphological and body composition features while comparing the accuracy of different skinfold-based equations in estimating FM% in a cohort of soccer referees. Forty-three elite international soccer referees (age 38.8 ± 3.6 years), who participated in the 2018 Russian World Cup, underwent body composition assessments with skinfold thickness and dual-energy X-ray absorptiometry (DXA). Six equations used to derive FM% from skinfold thickness were compared with DXA measurements. The percentage of body fat estimated using DXA was 18.2 ± 4.1%, whereas skinfold-based FM% assessed from the six formulas ranged between 11.0% ± 1.7% to 15.6% ± 2.4%. Among the six equations considered, the Faulkner's formula showed the highest correlation with FM% estimated by DXA (r = 0.77; R2 = 0.59 p < 0.001). Additionally, a new skinfold-based equation was developed: FM% = 8.386 + (0.478 × iliac crest skinfold) + (0.395 × abdominal skinfold, r = 0.78; R2 = 0.61; standard error of the estimate (SEE) = 2.62 %; p < 0.001). Due to these findings, national and international federations will now be able to perform regular body composition assessments using skinfold measurements. (c) 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

Numerical modelling of the punching behaviour of steel fibre reinforced self-compacting concrete flat slabs

Punching shear failure on flat reinforced concrete slabs of residential and commercial buildings is generally avoided by using transversal reinforcement and/or chapiters. The first option requires intense labour, mainly when densely flexural reinforcement exists in the potential punching failure region, with detrimental consequences in terms of costs of this construction solution. The second option has also extra costs due to the necessity of special arrangements of moulds for casting the chapiters. The interference of a chapiter on the flatness of the slab can also be a negative aspect from the architectonic point of view. The use of steel fibre reinforcement can be a solution to avoid both the conventional punching reinforcement and chapiters. Therefore, an experimental program was carried out to assess the potentialities of steel fibre reinforced self-compacting concrete (SFRSCC) for the punching resistance of flat slabs centrically loaded. This experimental program is described, and the main results are presented and analysed. To assess the potentialities of the Reissner-Mindlin FEM-based theory for modelling the behaviour of flat SFRSCC slabs submitted to punching loading configuration, new features were introduced in the out-ofplane shear constitutive law of the SFRSCC. These features are briefly described and the main focus was given on the modelling strategy adopted for simulating the punching tests.Fundação para a Ciência e a Tecnologia (FCT

Numerical simulation of the punching shear behaviour of self-compacting fibre reinforced flat slabs

This paper presents the numerical simulations of the punching behaviour of centrally loaded steel fibre reinforced self-compacting concrete (SFRSCC) flat slabs. Eight half scaled slabs reinforced with different content of hooked-end steel fibres (0, 60, 75 and 90 kg/m3) and concrete strengths of 50 and 70 MPa were tested and numerically modelled. Moreover, a total of 54 three-point bending tests were carried out to assess the post-cracking flexural tensile strength. All the slabs had a relatively high conventional flexural reinforcement in order to promote the occurrence of punching failure mode. Neither of the slabs had any type of specific shear reinforcement rather than the contribution of the steel fibres. The numerical simulations were performed according to the Reissner-Mindlin theory under the finite element method framework. Regarding the classic formulation of the Reissner-Mindlin theory, in order to simulate the progressive damage induced by cracking, the shell element is discretized into layers, being assumed a plane stress state in each layer. The numerical results are, then, compared with the experimental ones and it is possible to notice that they accurately predict the experimental force-deflection relationship. The type of failure observed experimentally was also predicted in the numerical simulations.This work is supported by FEDER funds through the Operational Program for Competitiveness Factors - COMPETE and National Funds through FCT - Portuguese Foundation for Science and Technology under the project “SlabSys – HFRC – Flat slabs for multi-storey buildings using hybrid reinforced self-compacting concrete: an innovative structural system” PTDC/ECM/120394/2010

Correlação entre ensaios com câmara termográfica e resistógrafo na avaliação da integridade de vigas antigas de madeira

Este trabalho de investigação pretende dar um contributo no campo das técnicas não destrutivas de inspecção e de diagnóstico de vigas antigas de madeira. Para o efeito, correlacionou-se os resultados obtidos através do uso do resistógrafo e da termografia no estudo de uma viga recolhida num edifício de habitação unifamiliar que foi sujeito a um processo de remodelação. Verificou-se que poderá haver uma cerca correlação entre ensaios. Contudo, também se recomenda a realização de um número mais expressivo de ensaios de amostras para ser possível apresentar uma conclusão mais fidedigna. A relevância desta possível correlação prende-se com o facto de poder haver uma alternância na realização destes ensaios consoante os condicionalismos do cenário de obra

Methodology for phytoplankton taxonomic group identification towards the development of a lab-on-a-chip

This paper presents the absorbance and fluorescence optical properties of various phytoplankton species, looking to achieve an accurate method to detect and identify a number of phytoplankton taxonomic groups. The methodology to select the excitation and detection wavelengths that results in superior identification of phytoplankton is reported. The macroscopic analyses and the implemented methodology are the base for designing a lab-on-a-chip device for a phytoplankton group identification, based on cell analysis with multi-wavelength lighting excitation, aiming for a cheap and portable platform. With such methodology in a lab-on-a-chip device, the analysis of the phytoplankton cells’ optical properties, e.g., fluorescence, diffraction, absorption and reflection, will be possible. This device will offer, in the future, a platform for continuous, autonomous and in situ underwater measurements, in opposition to the conventional methodology. A proof-of-concept device with LED light excitation at 450 nm and a detection photodiode at 680 nm was fabricated. This device was able to quantify the concentration of the phytoplankton chlorophyll a. A lock-in amplifier electronic circuit was developed and integrated in a portable and low-cost sensor, featuring continuous, autonomous and in situ underwater measurements. This device has a detection limit of 0.01 µ/L of chlorophyll a, in a range up to 300 µg/L, with a linear voltage output with chlorophyll concentration.European Regional Development Fund (ERDF) through the Interreg VA Spain-Portugal (POCTEP) 2014–2020 Program under grant agreement 0591_FOODSENS_1_E, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020, and by project NORTE-08-5369-FSE-000039 co-founded by the European Social Fund FSE and through National funds NORTE 2020 and Regional Operacional Programa of North 2014/2020. The University of Vigo work was funded by a Xunta de Galicia grant to the Biological Oceanography Research Group (Consolidación e estruturación de unidades). This output reflects only the views of the authors, and the program authorities cannot be held responsible for any use that may be made of the information contained therei