Jorge M. A. Saraiva

University of Aveiro | UA · Department of Chemistry

BACKGROUND There is a growing interest in industry to replace synthetic chemicals by natural products with bioactive properties. Aromatic plants are excellent sources of bioactive compounds that can be extracted using several processes. As far as oregano is concerned, studies are lacking addressing the effect of extraction processes in bioactivity...

As of November/December 2016, this highly cited paper received enough citations to place it in the top 1% of the academic field of Agricultural Sciences based on a highly cited threshold for the field and publication year (Data from Essential Science Indicators). AbstractBackground A large amount of wastes and by-products are generated during oliv...

As of November/December 2016, this highly cited paper received enough citations to place it in the top 1% of the academic field of Agricultural Sciences based on a highly cited threshold for the field and publication year (Data from Essential Science Indicators). The aim of this work was to determine the effectiveness of 17 essential oils to inhib...

During the desalting of salted cod, significant textural, histological, and biochemical changes occur. Understanding these changes is crucial for enhancing the preservation and extending the shelf life of desalted cod. This study aimed to investigate the physicochemical quality parameters and enzymatic activities during the desalting process of cod...

In this study, different extraction methods and conditions were used for the extraction of antioxidants from brown macroalgae Fucus spiralis. The extraction methodologies used were ultrasound-assisted extraction (ultrasonic bath and ultrasonic probe), extraction with a vortex, extraction with an Ultra-Turrax® homogenizer, and high-pressure-assisted...

Contact lenses (CLs) constitute an advantageous platform for the topical release of corticosteroids due to their prolonged contact with the eye. However, the lipophilic nature of corticosteroids hampers CLs' ability to release therapeutic amounts. Two approaches to improve loading and release of triamcinolone acetonide (TA) from poly(2-hydroxyethyl...

This study investigated the effects of high-pressure processing (HPP; 600 MPa/15 min) and microbial transglutaminase-catalyzed (MTG; 30 U·g of protein−1) crosslinking on the concentration of dissolved proteins (SOL), free sulfhydryl groups (SH), surface hydrophobicity (H0), and viscosity of pea protein isolates (PPI) at different concentrations (1–...

This study aimed to identify equivalent processing conditions using ultrasound (US), pulsed electric fields (PEF), and high-pressure processing (HPP) for shelf-life extension and to ensure the safety and quality of Reineta Parda apple puree (AP) in comparison to conventional thermal pasteurization (72 °C/15 s, CTP). The processing conditions were s...

In commercially available honey, the application of a heat treatment to prevent spoilage can potentially compromise its beneficial properties and quality, and these effects worsen with extended storage. The high-pressure processing (HPP) of honey is being explored, but its long-term impact on honey quality has not been characterised yet. This study...

The effect of thermal pasteurization (TP, 62.5 °C/30 min—conditions similar to those used in milk banks/hospitals, known as Holder pasteurization) and high-pressure pasteurization (HPP: 400–625 MPa/2.5–30 min) was studied on immunoglobulin (IgG, IgM and IgA) content, lysozyme activity and microbial load of donkey colostrum (in this case, after 40 d...

Contact lenses (CLs) have been suggested as drug delivery platforms capable of increasing the drug residence time on the cornea and therefore its bioavailability. However, when targeting the posterior segment of the eye, the drug released from CLs still encounters the barrier effect of the ocular tissues, which considerably reduces the efficacy of...

The escalating production of processed prickly pear products has led to a substantial rise in waste materials, particularly peel, which is rich in bioactive chemicals and holds the potential for value-added product development. However, the high perishability of these peels imposes effective preservation techniques. So, this work aimed to explore t...

Bone resident cells are constantly subjected to a range of distinct mechanical loadings, which generates a complex microenvironment. In particular, hydrostatic pressure (HP) has a key impact on modulation of cell function and fate determination. Although HP is a constant mechanical stimulus, its role in regulating the osteogenesis process within a...

Dairy cream, a common ingredient in various dishes and food products, is susceptible to rapid microbial growth due to its high water activity (≈0.97) and pH (≈6.7). Thus, it requires proper processing conditions to ensure food safety and extend shelf life. High-pressure processing (HPP) has emerged as a nonthermal food pasteurization method, offeri...

Despite being rich in starch, over half of acorn production is undervalued. High hydrostatic pressure was used to modify the properties of Q. pyrenaica (0.1 and 460 MPa for 20 min) and Q. robur (0.1 and 333 MPa for 17.4 min) acorn starches to obtain high-valued ingredients. Pressure significantly altered the span distribution and heterogeneity of t...

This study aimed to obtain a betalain-rich extract (BRE) from Opuntia ficus-indica peels and protect them through a holistic approach involving microencapsulation via spray-drying. To enhance the stability of the microencapsulated betalains, an antioxidant-rich extract (ARE) obtained through hydrothermal extraction from the residual material remain...

Nannochloropsis oculata is naturally rich in eicosapentaenoic acid (EPA). To turn this microalga into an economically viable source for commercial applications, extraction efficiency must be achieved. Pursuing this goal, emerging technologies such as high hydrostatic pressure (HHP) and moderate electric fields (MEF) were tested, aiming to increase...

As an alternative to commercial whole egg thermal pasteurization (TP), the sequential combination of moderate pressure (MP) and/or ultrasound (US) pre-treatments prior to a shorter TP was evaluated. The use of US alone or in combination with MP or TP resulted in an inactivation that was far from that of commercial TP. Nevertheless, when these three...

Opuntia ficus-indica fruits are a source of valuable compounds, presenting a high nutritional value and several health benefits. However, due to its low shelf life and increased production, there are considerable post-harvest losses of this cactus fruit. So, ways need to be found to drain the increased production of this fruit that is being wasted....

The interest in high hydrostatic pressure (HHP) is mostly focused on the inactivation of deleterious enzymes, considering the quality-related issues associated with enzymes in foods. However, more recently, HHP has been increasingly studied for several biotechnological applications, including the possibility of carrying out enzyme-catalyzed reactio...

High-pressure processing (HPP) can be used as a nonthermal pasteurization technique to overcome microbial safety issues of the raw ewes’ milk Serra da Estrela cheese without negatively influencing its quality, in particular, the lipid composition partly responsible for Serra da Estrela cheese’s sensorial and textural attributes. The aim of this wor...

Serra da Estrela cheese with a Protected Designation of Origin (PDO) is a traditional cheese that is wrapped in paper without vacuum. High-pressure processing (HPP), which requires vacuum packaging of the cheese, has been used for its cold pasteurization to overcome safety issues. In this study, two packaging systems were studied: non-vacuum grease...

Yoghurt fermented under sub-lethal high pressure (10, 20, 30 and 40 MPa at 43 °C), and afterward placed under refrigeration (4 °C for 23 days) was studied and compared with yoghurt fermented at atmospheric pressure (0.1 MPa). For a deeper analysis, metabolite fingerprinting by nuclear magnetic resonance (NMR), sugars and organic acids assessment by...

As a possible alternative to commercial thermal pasteurization11 Thermal pasteurization (TP) (TP, 60 ºC/3.5 min) of liquid whole egg22 Liquid whole egg (LWE) (LWE), a pasteurization based on the application of pressure pre-treatments (50 – 250 MPa/5 min) before a shorter TP (60 ºC/1.75 min) was investigated. These combined treatments inactivated 3....

This study tested hyperbaric storage (25–150 MPa, for 30 days) at room-temperature (HS/RT, 18–23 °C) in order to control the development of Byssochlamys nivea ascospores in apple juice. In order to mimic commercially pasteurized juice contaminated with ascospores, thermal pasteurization (70 and 80 °C for 30 s) and nonthermal high pressure pasteuriz...

The quality standards for the export of chestnuts generate large quantities of rejected fruits, which require novel processing technologies for their safe industrial utilization. This study aimed to investigate the impact of high-pressure processing (HPP) and hydrothermal treatments (HT) on the physicochemical properties of rejected chestnut starch...

The study of the suitability of two isolation processes to produce cellulose nanofibers (CNFs) from Salicornia ramosissima waste, with potential applicability as a reinforcing agent of polymeric composites was carried out. To separate the cellulose fibrils from the cell wall and obtain CNFs an alkaline treatment was applied followed by a bleaching...

Opuntia fruits are recognized for their richness in nutrients and in bioactive compounds, being also highly appreciated by consumers as a juice. Nevertheless, without further processing, prickly pear juices have a short shelf-life, hampering their commercial use. In this work, thermal (TP) and high-pressure (HPP) pasteurization were applied to juic...

The changes in microbiological, physiochemical, and textural properties in fresh cheeses made from either cow or goat milk were observed under hyperbaric storage (HS, 50–100 MPa) at room temperature (RT) and compared with refrigerated storage under normal atmospheric pressure for 60 days. An initial microbial growth inhibition was observed for both...

Egg yolk (EY) thermal pasteurization (TP; 60 °C/3 min) preceded by pressure pre-treatments (50 – 400 MPa/5 min) was evaluated, as an attempt to replace commercial TP (60 °C/6.2 min). These combined treatments inactivated 1.8 to at least 6.1 log10 cycles of Salmonella Senftenberg 775/W, whereas commercial TP achieved 3.3 log10 cycles, probably assoc...

Firstly, fish soup preservation by hyperbaric storage (HS; 25-100 MPa) at room temperature (RT; 20°C) was compared to refrigeration (RF; 4°C) as a way to restrain microbial growth. Additionally, to greater microbial growth restrain, HS at higher pressures (above 75 MPa) revealed also considerable levels of microbial inactivation, leading to study a...

Polyphenol-rich foods protect the cellular systems of the human body from oxidative damage, thereby reducing the risk of chronic diseases such as cardiovascular disease (CVD). We investigated the effect of phenolic-rich apple/berry juice (chokeberry, blueberry, and cranberry) on lipidemic profiles in overweight/obese women. The 6 week single-arm pr...

Honey is a value-added product rich in several types of phenolic compounds, enzymes, and sugars recently explored in biomedical and food applications. Nevertheless, even though it has a low water activity (aW ≈ 0.65) that hinders the development of pathogenic and spoilage microorganisms, it is still prone to contamination by pathogenic microorganis...

Fungi, and their spores, are responsible for the spoilage of several foods and plants and are susceptible to contamination with mycotoxins, which have associated health hazards. In this context, proper methodologies for inactivating such fungi and controlling mycotoxin production are critical. High-pressure processing (HPP) has recently become popu...

The possibility of using a sublethal moderate pressure¹(MP) pre-treatment followed by a shorter and so gentler thermal pasteurization² (TP), (MP-TP), was assessed, as an alternative to commercial egg white³ (EW) TP, by evaluating the lethal efficacy against Salmonella Senftenberg and influence on the functional and physicochemical properties of EW....

In order to study the possible effect of several compressions and decompressions (C/D) cycles performed during hyperbaric storage (HS) in microbial behaviour, raw milk was stored under 75 MPa at room temperature (RT) for 31 days, under three different total C/D cycles conditions, 5, 31 and 93. The different C/D cycles achieved similar microbiologic...

Acorns are an abundant but despised fruit in Portugal. To explore this resource, the effect of different dehusking methods (thermal dehusking and dehusking by drying) on the phenolic contents and antioxidant activity of different acorn species from Peneda-Gerês National Park was studied. Regarding the free phenolics, the phenolic contents and antio...

Raw milk (a highly perishable food) was preserved at variable room temperature (RT) under hyperbaric storage (HS) (50-100 MPa) for 60 days and compared with refrigeration (RF) under atmospheric pressure (AP) on quality, nutritional, and endogenous enzyme activity parameters. Overall, a comparable raw milk preservation outcome was observed between s...

Two highly perishable dairy products (cow’s and goat’s fresh cheese (FC)), were stored under hyperbaric storage at room temperature (HS/RT, 50-100MPa) and compared with RF (4ºC), for 60 days. HS/RT (≥75MPa) lead to a more stable volatile organic and fatty acid profiles, reducing lipid oxidation rate, particularly for cow’s FC, resembling more to FC...

High pressure pasteurised (HPP) milk was stored by hyperbaric storage at room temperature (HS/RT) (50-100 MPa at 20 °C) and compared with refrigeration/(RF), to assess the effect on two pathogens surrogates and a pathogenic, up to 120 days, and on fatty acids, volatile organic compounds (VOCs) and secondary lipid oxidation over 60 days. HS/RT (75-1...

The effects of hyperbaric storage (HS, 50–100 MPa) at room temperature (RT) on endogenous and inoculated pathogenic surrogate vegetative bacteria (Escherichia coli, Listeria innocua), pathogenic Salmonella enterica and bacterial spores (Bacillus subtilis) were assessed and compared with conventional refrigeration (RF) at atmospheric pressure for 60...

Meat constitutes one the main protein sources worldwide. However, ethical and health concerns have limited its consumption over the last years. To overcome this negative impact, new ingredients from natural sources are being applied to meat products to obtain healthier proteinaceous meat products. Algae is a good source of unsaturated fatty acids,...

The aim of this study was to evaluate the impact of high-pressure processing (HPP) on the long-term storage of chocolate fillings at room temperature, compared with conventional storage at lower temperatures. Dark chocolate fillings were treated at different pressure levels, holding times and stored at 20 ºC for 12 months. Unprocessed batches were...

Biobased and biodegradable plastic mulch film (aka, mulch biofilm) has emerged as a sustainable alternative to conventional plastic mulch films in agriculture, promising to reduce soil contamination with plastic residues through in situ biodegradation. However, current standards certifying biodegradable plastics cannot predict biodegradability in n...

Aurantiochytrium sp. is an emerging alternative source of polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA), and squalene, playing an important role in the phasing out of traditional fish sources for these compounds. Novel lipid extraction techniques with a focus on sustainability and low environmental footprint are being developed fo...

High-pressure processing (HPP) is an emergent technology for nonthermal pasteurization of foods, which here demonstrates the potential to be used by the chestnut industry. This study evaluated HPP as a post-harvest processing technology to control molds and insect larvae proliferation in chestnuts (Castanea sativa Mill.) and improve the fruit's she...

A new nonthermal food pasteurization approach is here presented for the first time, proposed to be called low-pressure long-time (LPLT) pasteurization or moderate pressure pasteurization (MPP) by hyperbaric inactivation (HI). To test this novel pasteurization process on raw milk, MPP by HI was carried out at three different pressure levels (150, 20...

The São Domingos mine is within the Iberian Pyrite Belt, a mining district with large concentrations of polymetallic massive sulfide deposits. Mine waste heaps are considered extreme environments, since they contain high total concentrations of potentially hazardous elements (PHE), which contribute to inhibiting the development of most plants. Auto...

The major concern regarding the bacteriophage (or phage) therapy approach is the regrowth of bacteria after treatment, a consequence of the emergence of phage-resistant mutants. However, this limitation can be overcome by combining different therapies. In this study, the potential of combining phage phT4A with pressure storage (HS) to enhance the c...

Serra da Estrela protected designation of origin (PDO) cheese is manufactured with raw milk from Bordaleira and/or Churra Mondegueira da Serra da Estrela sheep breeds. Several socio-environmental shortcomings have reduced production capacity; hence, treatments that may contribute to its efficient transformation into cheese are welcome. High-pressure...

Microalgae, as a photosynthetic autotrophic organism, contain a variety of bioactive compounds, including lipids, proteins, polysaccharides, which have been applied in food, medicine, and fuel industries, among others. Microalgae are considered a good source of marine lipids due to their high content in unsaturated fatty acid (UFA) and can be used...

The high oil content of nuts and its fatty acid profile with biological proprieties positively affect blood lipids and lipoproteins. Nuts are low in saturated and high in unsaturated fatty acids (MUFA and PUFA) and are rich sources of other essential nutrients. Vegetable oils extraction is usually done through conventional methods like Soxhlet, col...

High-pressure processing (HPP) is one of the most successful nonthermal technologies that have been commercialized in the food processing industry in recent years. It involves the usage of high-pressure (usually between 450 and 600 MPa in the food industry) to achieve pasteurization effects. HPP has been commonly applied to prolong the shelf life o...

Consumer awareness for healthier and more natural foods is increasing, promoting fruit and vegetable consumption, leading to a considerable increase of food by-products, with several environmental concerns associated. Because fruits and vegetables are rich in bioactive compounds, their by-products can be interesting sources of phenolic compounds, a...