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Honey is natural sweet substance produced by Apis mellifera, which is consumed as a high nutritive value food. The physicochemical quality criteria of honey are well specified by the European Legislation (EC Directive 2001/110) [1]. The quality properties of honey can be diminished by the influence of heating in the thermal pasteurization of honey [2]. As an alternative to conventional thermal pasteurization, the non-thermal high pressure processing has potential to produce safety food with similar characteristics to the raw unprocessed foods [3]. Therefore, the purpose of this work was to study the effect of three treatments: 1) high pressure (725 MPa for 10 minutes); 2) high pressure with temperature (725 MPa for 10 minutes at temperature of 50 °C); and 3) thermal treatment (75 °C for 5 minutes) on the physicochemical parameters (moisture, pH, electrical conductivity, free acidity, diastase activity and hydroxymethylfurfural content) of a Portuguese heather honey. The results obtained for several physicochemical parameters were significantly different among the samples under the different treatments, for instance, the HMF content. This parameter, widely recognized as indicator of honeys' freshness [4], depends on several factors, such as temperature, time of heating and storage conditions [5]. The value of HMF in the raw honey was 5,5 ± 0,5 mg.kg−1 of honey (EU limit is 40 mg·kg−1), ensuring that it was a fresh product that has not been subjected to heating or inadequate storing conditions. Concerning the treatments, the ANOVA results showed that the amounts of HMF did differ significantly (P-value= 0.0315). The thermal treatment significantly increased the HMF concentration comparing with the raw honey (P-value= 0.0355). The preliminary results did not show significant increase in the HMF content when high pressure processing, with and without temperature, were applied. Further studies should be performed to confirm that high pressure processing has no adverse effect on the honey quality. ; Thanks are due to the University of Aveiro, the Portuguese Fundação para a Ciência e a Tecnologia (FCT), EU, QREN, FEDER and COMPETE for funding the Organic Chemistry Research Unit (project PEst- C/QUI/UI0062/2013) and to the Polytechnic Institute of Bragança. ; info:eu-repo/semantics/publishedVersion

Background Plant proteins possess promising technological-functional properties that can be used for the development of innovative protein systems. Following the global requirements of environmentally friendly politics, green and cost-effective processing technologies, such as ohmic heating and high pressure processing are of great interest. These technologies have demonstrated their potential to modify protein structure and therefore their function, opening interesting possibilities for the design of functional food systems. However, these innovations must also include nutritional and health/wellness aspects, such as the interaction with other food components, and the behavior in the gastrointestinal tract (digestibility and bioavailability). Scope and approach This review addresses the most promising technological-functional attributes of plant proteins, as well as considerations and strategies needed for the development of innovative food systems. New insights will also be provided on how emerging processing technologies such as ohmic heating and high pressure processing can affect the behavior of proteins. The processing effects in proteins structure and in their technological-functional properties and ultimately in the biofunctional and nutritional aspects of foods made therefrom will be critically discussed. Key findings and conclusions Fundamental research regarding the relationship between structural modifications and functionality of more conventional proteins is still required. Furthermore, additional research is necessary on proteins from less studied sources, highlighting those displaying both functional and quality parameters of interest. Emergent processing technologies can help guaranteeing the quality and preservation of foods, as well as act as effective tools to develop technological-functional attributes of food proteins ensuring nutritional and health/wellness aspects. ; This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic ...

12 pages, 3 figures, 3 tables ; The objective of this study was the quality loss inhibition of hake (Merluccius merluccius) during the frozen storage. For it, the effect of a previous high-pressure (HP) treatment (150–450 MPa for 2 min) was analysed throughout a 5-month storage at − 10 °C. Quality changes were monitored by complementary chemical analyses. Inhibition (p 0.05) on the K value, polyene index and formation of peroxides and thiobarbituric acid reactive substances was achieved. Additionally, a multifactor ANOVA test (pressure and frozen storage time effects; i.e. comparison among HP treatments) showed an inhibitory effect (p < 0.015) on DMA and FFA formation, this effect increasing with pressure level applied. This inhibitory effect on the formation of such molecules related to quality loss can be explained on the basis of the damage caused to different kinds of enzymes such as trimethylamine oxide demethylase, lipases and phospholipases, so that their activity during the subsequent frozen storage would decrease. The work here presented provides for the first time information concerning the employment of HP technology to inhibit the DMA, FA and FFA formation during the frozen storage of hake. Further research focussed on commercial frozen conditions (− 18 °C) and including sensory and nutritional aspects is foreseen ; The work was supported by the Consejo Superior de Investigaciones Científicas (CSIC) (Spain) through the Research Project 2017-70E032; by Fundação para a Ciência e a Tecnologia (FCT Portugal), European Union, QRN, FEDER, COMPETE through founding of the Organic Chemistry Research Unit (QOPNA) (project PEst-C/QUI/UI0062/2013; FCOMP-01-0124-FEDER-037296); and by Formula Grant No. 2011-31200-06041 and 2012-31200-06041 from the USDA National Institute of Food and Agriculture ; Peer reviewed

Honey is a natural sweet substance produced by Apis mellifera, which has great potential to serve as a natural food antioxidant. The physicochemical quality criteria of honey are well specified by the European Legislation (EC Directive 2001/110). The quality properties of honey can be diminished by the influence of heating. As an alternative to the conventional thermal pasteurization, nonthermal high pressure processing (HPP) has potential to produce safe food with similar characteristics to the raw unprocessed foods. The aim of this study was to investigate the effect of HPP (725 MPa for 10 minutes) and HPP with temperature (725 MPa for 10 minutes at 50 °C) on physicochemical properties (moisture, pH, electrical conductivity, free acidity, diastase activity and hydroxymethylfurfural content) of a heather honey in comparison with thermal treatment (75 °C for 5 minutes) and unprocessed honey. The effect of storage (6 months) in processed and unprocessed samples was also investigated. The results showed significant differences in some physicochemical parameters, for instance, the hydroxymethylfurfural content, an indicator of honeys' freshness that depends on several factors, such as temperature, time of heating and storage conditions. An electronic tongue (ET) with lipidic membranes was used to evaluate the differences between all honey groups. A linear discriminant analysis to the ET results showed that the processed and unprocessed honey samples at day 0 (when treatments were applied) and after the storage have matrix differences that allows a complete separation of groups. The correlation between physicochemical and electronic tongue data showed the advantages of this data fusion. ; info:eu-repo/semantics/publishedVersion

7 páginas, 4 tablas, 3 figuras ; In this work, we studied the effect of high-pressure processing (HPP) pre-treatments (150, 300 and 450 MPa for 0, 2.5 and 5 min) on key enzyme activities in Atlantic mackerel (Scomber scombrus) during frozen storage (3 months of accelerated storage, − 10 °C). Except for a minor decrease from treatment at 450 MPa, no substantial effect on acid phosphatase activity was observed. In contrast, cathepsins B and D and lipase were affected by HPP and frozen storage. Increasing the pressure reduced cathepsin B and lipase activities. Generally, increasing the holding time at 150 MPa increased the activity of cathepsin B and lipase (except at month 1), while increasing the holding time at 300 MPa reduced the lipase activity, and no effect was observed at 450 MPa. Overall, cathepsin D activity increased with frozen storage time and for treatments at 300 MPa but decreased at 450 MPa. This work provides novel information of HPP pre-treatments application, lowering enzyme activity during frozen storage of Atlantic mackerel ; The financial support of the Xunta de Galicia (Spain project no. 10TAL402001PR, 2010–2012) and of Research Unit 62/94 QOPNA, along with the European Union, QREN, FEDER and COMPETE (project no. Pest-C/QUI/UI0062/2013; FCOMP-01-0124-FEDER-037296) is gratefully acknowledged. This work was supported also by formula grant nos. 2011-31200-06041 and 2012-31200-06041 from the USDA National Institute of Food and Agriculture ; Peer reviewed

6 páginas, 4 figuras ; We determined high pressure processing (HPP) effects on the activities of cathepsins B and D in the muscles of mackerel (Scomber scombrus) and horse mackerel (Trachurus trachurus). In mackerel, the cathepsin B activity decrease reached 40% at 450 MPa while in horse mackerel, low and intermediate pressures (150 and 300 MPa) caused an activity increase (30%) but at 450 MPa a decrease of up to 60%. In both species, cathepsin D activity increased after a 300 MPa treatment (up to 2-fold for mackerel and 60% for horse mackerel) and decreased on a 450 MPa treatment. The activity increase is probably due to HPP damage of lysosome releasing enzymes into the fish muscle. Based on the HPP effects on the activities of cathepsins B and D, 450 MPa may be used to reduce the proteolytic activity of cathepsin B prior to chilled or frozen storage of these fish species ; Supported by the Xunta de Galicia, Spain Project 10TAL402001PR, 2010-2012, and FCT (Portugal), European Union, QREN, FEDER and COMPETE thorough QOPNA research unit, Project PEst-C/QUI/UI0062/2013; FCOMP-01-0124-FEDER-037296. Also supported by he USDA National Institute of Food and Agriculture, Grants No. 2011-31200-06041 and 2012-31200-06041 ; Peer reviewed

We determined high pressure processing (HPP) effects on the activities of cathepsins B and D in the muscles of mackerel (Scomber scombrus) and horse mackerel (Trachurus trachurus). In mackerel, the cathepsin B activity decrease reached 40% at 450 MPa while in horse mackerel, low and intermediate pressures (150 and 300 MPa) caused an activity increase (30%) but at 450 MPa a decrease of up to 60%. In both species, cathepsin D activity increased after a 300 MPa treatment (up to 2-fold for mackerel and 60% for horse mackerel) and decreased on a 450 MPa treatment. The activity increase is probably due to HPP damage of lysosome releasing enzymes into the fish muscle. Based on the HPP effects on the activities of cathepsins B and D, 450 MPa may be used to reduce the proteolytic activity of cathepsin B prior to chilled or frozen storage of these fish species ; Supported by the Xunta de Galicia, Spain Project 10TAL402001PR, 2010-2012, and FCT (Portugal), European Union, QREN, FEDER and COMPETE thorough QOPNA research unit, Project PEst-C/QUI/UI0062/2013; FCOMP-01-0124-FEDER-037296. Also supported by he USDA National Institute of Food and Agriculture, Grants No. 2011-31200-06041 and 2012-31200-06041 ; SI