Raúl Pérez-Gálvez

Raúl Pérez-Gálvez
University of Granada | UGR · Department of Chemical Engineering

Doctor of Engineering

About

46
Publications
8,998
Reads
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548
Citations
Citations since 2016
18 Research Items
456 Citations
2016201720182019202020212022020406080
2016201720182019202020212022020406080
2016201720182019202020212022020406080
2016201720182019202020212022020406080
Additional affiliations
June 2009 - present
University of Granada
Position
  • Professor (Assistant)
Description
  • Enzymatic hydrolysis of fish materials Bioactivities of fish protein hydrolysates: antihypertensive, antioxidant, anticholesterolemic Membrane ultrafiltration Diet formulation for larvae feeding Simulation and modelization

Publications

Publications (46)
Article
Full-text available
In this work, we evaluated the physical and oxidative stabilities of 5% w/w fish oil-in-water emulsions stabilized with 1%wt Tween20 and containing 2 mg/mL of protein hydrolysates from olive seed (OSM–H), sunflower (SFSM–H), rapeseed (RSM–H) and lupin (LUM–H) meals. To this end, the plant-based substrates were hydrolyzed at a 20% degree of hydrolys...
Article
The secondary structure of whey protein concentrate hydrolysate (WPCH), used as an emulsifier in oil delivery systems, was investigated using Synchrotron Radiation Circular Dichroism (SRCD). The effect of pH on the conformation of peptides in solution and adsorbed at the oil/water interface, as well as the thermal stability of the systems was studi...
Article
Blood is the main by‐product from slaughterhouses bearing high levels of suspended solids (18% w/w) and BOD5 (250 000–375 000 mg O2/L), which makes difficult its handling and disposal. This study proposes the valorisation of blood protein to produce enzymatic hydrolysates rich in haemic iron and antioxidant peptides. Haemic iron presents higher bio...
Article
Full-text available
Inflammation is the response of the immune system to harmful stimuli such as tissue injury, infection or toxic chemicals, which has the aim of eliminating irritants or pathogenic microorganisms and enhancing tissue repair. Uncontrolled long-lasting acute inflammation can gradually progress to chronic, causing a variety of chronic inflammatory disea...
Article
Diabetes prevalence has been rapidly increasing worldwide, and there is a need for searching natural compounds to prevent and treat it. Bioactive peptides derived from insect protein would be an interesting sustainable option. However, the potential of insects such as mealworms (Tenebrio molitor) as source for antidiabetic peptides has not been wid...
Article
Full-text available
The incorporation of lipid ingredients into food matrices presents a main drawback—their susceptibility to oxidation—which is associated with the loss of nutritional properties and the generation of undesirable flavors and odors. Oil-in-water emulsions are able to stabilize and protect lipid compounds from oxidation. Driven by consumers’ demand, th...
Article
The increase of world population has led to the need of searching new protein sources as insects, whose harvesting is economically and environmentally sustainable. This study explores the biological activities (angiotensin-converting enzyme inhibition, antioxidant capacity, and dipeptidyl peptidase IV inhibition) of Tenebrio molitor hydrolysates pr...
Article
Fish meal is commonly employed as protein source in aquaculture diets. The enrichment of this ingredient with fish protein hydrolysates (FPH) and free amino acids has proved to improve larval development and feed assimilation. In this work, we produced tuna head hydrolysates using a sequential enzymatic treatment employing Alcalase and Flavourzyme....
Article
The enzymatic hydrolysis of milk proteins yield final products with improved properties and reduced allergenicity. The degree of hydrolysis (DH) influences both technological (e.g., solubility, water binding capacity) and biological (e.g., angiotensin-converting enzyme (ACE) inhibition, antioxidation) properties of the resulting hydrolysate. Phenom...
Chapter
The vast diversity of marine organisms is a source of enormous potential for obtaining bioactive compounds for use in the food industry. In this context, discards, which are defined as the fraction of the fish catch that is not retained onboard but rejected to the sea due to commercial standards, fishing regulations, or them being nontarget species...
Chapter
This article is focused on the application of pressing for the treatment of fish discards, which are the main by-products from the fishing industry. First, the extraction of fish oil from fish discards by using pressing operations is introduced. Particularly, the influence of cooking and pressing variables on the final oil quality is described. Sec...
Article
Full-text available
First-feeding diets employed in the rearing of meagre (Argyrosomus regius) larvae are based on live preys that are commonly enriched to compensate for their deficiency of essential fatty acids. A feeding trial was conducted on meagre larvae (Argyrosomus regius) fed rotifer (Brachionus plicatilis) and Artemia salina enriched in lipids from an emulsi...
Article
Fish protein hydrolysates (FPH) from horse mackerel were produced by employing an enzyme mixture of subtilisin and trypsin. The antioxidant activity of fish hydrolysates (DPPH scavenging activity, Fe²⁺ chelating activity and Fe³⁺ reducing power) was modelled as a function of the operating conditions for the hydrolysis (i.e. protein concentration, t...
Article
Fish protein hydrolysates from Mediterranean horse mackerel were produced by using a mixture of two commercial endoproteases (i.e. subtilisin and trypsin) at different levels of substrate concentration (2.5 g L(-1), 5 g L(-1), and 7.5 g L(-1) of protein), temperature (40 °C, 47.5 °C, and 55 °C) and percentage of subtilisin in the enzyme mixture (0%...
Article
Background: Fish discards represent an important underutilization of marine resources. This study evaluated the up-grading of the protein fraction of blue whiting (Micromesistius poutassou) discards by the production of fish protein hydrolysates (FPH) exhibiting functional, antioxidant, angiotensin-I converting enzyme (ACE)-inhibitory and antigeni...
Article
Full-text available
The current application of the zero discards policy in EU fisheries poses economic and logistic problems to fishing vessels, which are obliged to retain and preserve unwanted catches on board. The installation of compaction devices on board can effectively reduce the space requirements and the refrigeration loads to store these materials on board. In...
Article
In enzymatic reactions, the modeling of the degree of hydrolysis (DH) is desirable given its influence on many functional and biological activities. Empirical approaches are preferred to phenomenological ones to model the complexity of enzymatic reactions. Artificial Neuronal Networks (ANN) are able to process large sets of data where no linear rel...
Article
The new EU fisheries regulations state that all catches from pelagic fisheries must be landed from the 1st January 2015 on. Consequently, the development of new techniques for the up-grading of these discards is required. The aim of this work was to study the variations of the lipid profile and nutritional value of the oil extracted from four disca...
Article
The aim of this research was to study the influence of the gastrointestinal digestion on the bioactivity of goat milk protein hydrolysates prepared with subtilisin, trypsin and a combination of these two enzymes. All hydrolysates had excellent angiotensin converting enzyme (ACE) inhibitory activity, antioxidant activity and bile acid-binding capaci...
Article
The aim of this work was to seasonally characterize the nutritional quality of oil extracted from small-spotted catshark (Scyliorhinus canicula) and bogue (Boops boops). The proximate composition, lipid profile and regiodistribution of the fatty acid in the glycerol backbone were analyzed. In addition, three nutritional indexes were calculated (ath...
Article
Fish protein hydrolysates (FPH), produced from the six main discard species from the West Mediterranean Sea (sardine, horse mackerel, axillary seabream, bogue, small-spotted catshark and blue whiting) were tested for their bile acid binding capacity. This capacity is directly linked to the ability to inhibit bile reabsorption in the ileum and there...
Article
Background Amino acid-based fertilisers increase the bioavailability of nitrogen in plants and help withstand stress conditions. Besides, porcine blood protein hydrolysates are able to supply iron, which is involved in chlorophyll synthesis and improves the availability of nutrients in soil. A high degree of hydrolysis (DH) is desirable when produc...
Article
In this work, goat milk proteins were hydrolyzed by different treatments consisting sequential or simultaneous combinations of subtilisin and trypsin. The hydrolysate showing the highest angiotensin converting enzyme (ACE) inhibitory activity was submitted to ultrafiltration in the concentration mode through tubular ceramic membranes of 50 and 15 k...
Article
Full-text available
A global process for the production of goat milk hydrolysates enriched in angiotensin converting enzyme (ACE) inhibitory peptides was proposed. Firstly, the protein fractions (caseins and whey proteins) were separated by ultrafiltration through a 0·14 μm ceramic membrane. The casein fraction obtained in the retentate stream of the above filtration...
Article
The aim of this study was to evaluate the influence of the processing conditions (pretreatment temperature: 5–55 °C, pressure: 60–120 bar and number of pressing stages: 1–3) on the yield and quality (free fatty acids, peroxide value, p-anisidine and Rancimat induction period) of the oil extracted from whole sardine by hydraulic pressing. Experiment...
Article
Full-text available
BACKGROUND Discards are an important fraction of the by-products produced by the fishing industry. As a consequence of their low commercial acceptance, it is necessary to provide added value to these underutilized materials. In this study the lipid fraction of three discarded fish species in the western Mediterranean Sea, namely sardine (Sardina pi...
Article
BACKGROUND. The press juices resulting from a compacting operation on fish by-products were subjected to a depuration treatment in order to reduce their high COD (120 g O included an initial de-particulation step by means of two metallic filter cartridges of 465 µm and 250 µm, followed by a concentration with a 200 nm ultrafiltration ceramic membra...
Article
Five discarded fish species in the Alboran Sea, namely axillary seabream (Pagellus acarne), small-spotted catshark (Scyliorhinus canicula), sardine (Sardina pilchardus), horse mackerel (Trachurus mediterraneus), and bogue (Boops boops) were evaluated as novel sources for the production of omega-3 polyunsaturated fatty acids (PUFAs). The lipid conte...
Chapter
By-products of fish industry can account for up to 50% depending on the industrial process. They contain a high level of lipids: mainly polyunsaturated fatty acids (PUFAs) and a considerable fraction of EPA and DHA. These compounds present benefits for health such as: prevention of diabetes, allergy and some types of cancer, as well as anti-thrombo...
Chapter
Fish by-products are an inexpensive and easily available raw material which have been traditionally disposed of or used in animal feed or fertilization, i.e., fish feed, fish oil, organic fertilizers. Driven by the current development in biotechnology, and more specifically in separation and purification processes, many approaches have been propose...
Chapter
Full-text available
Biotechnology advances for marine by-products conversion into products of interest are numerous. In order to give maximum elements of understanding, it is essential to define the framework of this research to understand why and how bioconversion technologies are applicable. It is essential to look beyond the technical and technological advances on...
Article
The operational parameters of the Rancimat method (airflow rate, sample weight and temperature) were studied to determine their effects on the oxidative stability index (OSI) of cod liver oil. To this end, experimental data were firstly fitted to a complete quadratic model and an ANOVA analysis was performed, which concluded that airflow rate and t...
Article
Goat milk protein was hydrolysed with subtilisin and trypsin. As input variables, temperature was assayed in the interval 45-70 °C for subtilisin and 30-55 °C for trypsin, while the enzyme-substrate ratio varied from 1 to 5%. The effect of the input variables on the degree of hydrolysis and ACE-inhibitory activity (output variables) was modelled by...
Book
The shortage of marine resources calls for the implementation of new technological processes for providing a better utilization of waste and by-products from fisheries and fish processing activities. Most of these by-products are currently used as raw materials for animal feed. It is estimated that their utilization in human foodstuffs, nutraceutic...
Book
The shortage of marine resources calls for the implementation of new technological processes for providing a better utilization of waste and by-products from fisheries and fish processing activities. Most of these by-products are currently used as raw materials for animal feed. It is estimated that their utilization in human foodstuffs, nutraceutic...
Article
Full-text available
In this work, sardine fish was processed in a hydraulic press in order to obtain a solid cake and a press juice presenting solid, aqueous, and oil phases. The influence of pressing conditions, such as total pressure (50–350 bar), compression speed (0.935–3.135 cm/min), number of pressing stages (1–5), and time of relaxation between two consecutive...
Article
Full-text available
This paper assesses the performance of three ceramic membranes of average pore size 50 nm, 200 nm and 1.4 μm in the treatment of the press liquor resulting from a compaction operation of sardine by-products. To this end, 2 L of pre-filtered press liquor with an average protein content of 44 g/L were filtered during 3 h through the three membranes a...
Article
Protein from porcine blood meal was hydrolysed with Alcalase to obtain a final revalorised product suitable, for example, to take part in the composition of an organic fertiliser. Three experimental factors of the reaction (pH, temperature and enzyme–substrate ratio) were optimised by means of a statistically designed experiment and response surfac...
Article
Full-text available
A feeding trial was conducted to evaluate the effect of the supplementation of hydrolysates from tuna head on the survival and growth of Penaeus vannamei. To this end, a feeding trial was performed on eleven groups of shrimps of average weight 4.34 g. Every group was distributed into three tanks (30 shrimps per tank of 150 L) and was fed with one o...
Article
The global harvesting of marine products has increased from around 17 million tons in the 1950s to a current average amount of 85 million tons. The Food and Agriculture Organization (FAO) estimates that an annual average of 27 million tons of non-targeted species are caught and thrown back into the sea, what means that near third of the fish volume...
Article
The fish and aquaculture activities produce an important volume of by-products due to discards and processing on board and in land. These residues (fillet cuts, bones, heads, viscera and tails) require to be processed in order to not create a significant environmental problem and to maintain the economical viability of the fisheries sector. The pre...
Chapter
Full-text available
Introduction : A direct consequence of traditional fishing practices is the considerable quantities of wastes and byproducts that are generated. They represent an economical and environmental problem since not all obtained from the sea is adequately used but thrown back into the sea as a waste. With the aim of classifying and quantifying the by-pro...
Article
Fresh sardine (employed as discard model species) was pressed with a hydraulic press in order to obtain a partially dewatered cake (whose volume represents between 55% and 60% of the initial volume of raw material) and a 3-phase press liquor comprising an aqueous fraction, an oil fraction and a variable amount of suspended solids. Pressing conditio...
Article
Full-text available
In the framework of the future application of a zero-discard policy in EU fisheries, this thesis aims to develop and implement an efficient and integral waste management both on board the fishing vessels and in land (fish auctions and fish processing industry). To this end, it proposes a compaction operation able to reduce the volume and the water...

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