Effect of pre-treatment on the generation of dipeptidyl peptidase-IV- and prolyl endopeptidase-inhibitory hydrolysates from bovine lung

peer-reviewedThe aim of this work was to study the effect of two different pre-treatments, high temperature (100 °C, 5 min) and high pressure (600 MPa, 3 min), on the potential of the enzymes papain, collagenase and Alcalase® to generate bioactive hydrolysates containing dipeptidyl peptidase-IV- (DPP-IV; EC 3.4.14.5) and prolyl endopeptidase- (PEP; EC 3.4.21.26) inhibitory peptides from bovine lung. Both pre-treatments resulted in an increase in the degree of hydrolysis over a 24 h period (P < 0.001) and significantly increased the DPP-IV- and PEP-inhibitory activities of the generated hydrolysates (P < 0.001). Generated hydrolysates included an Alcalase hydrolysate of pressure-treated bovine lung, which was the most active, and showed DPP-IV and PEP half-maximal inhibitory concentration (IC50) values of 1.43 ± 0.06 and 3.62 ± 0.07 mg/ mL, respectively. The major peptides contained in this hydrolysate were determined by liquid chromatography-tandem mass spectrometry, and results demonstrated that bovine lung is a good substrate for the release of bioactive peptides when proper pre-treatment and enzymatic treatment are applied

Online tools to support teaching and training activities in chemical engineering: enzymatic proteolysis

The practical teaching or training of enzymatic proteolysis can prove challenging because of the lengthy duration of the process, the complexity of identifying short amino acid sequences, the high cost of the enzymes, and the need to use very specific equipment. There are several freely-available online tools that, despite being employed by scientists to help identify bioactive peptides, are not commonly used for teaching and training activities. This work summarises the most common protein and peptide databases along with other tools that allow one to simulate enzymatic hydrolysis of a given protein and to study the structure, physicochemical properties, bioactivity, toxicity, allergenicity, and even the bitterness of the resulting peptides. Overall, in silico tools can be used during the teaching and training of chemical engineers as innovative alternatives to conventional laboratory work and theoretical classes

Bioaccessibility of polyphenols and antioxidant capacity of fresh or minimally processed modern or traditional lettuce (Lactuca sativa L.) varieties

Modern city lifestyle is characterized by an increased demand for fresh or minimally processed foods. Lettuce (Lactuca sativa L.), mainly iceberg lettuce, is the main vegetable used during the manufacture of fresh-cut salads. The current study evaluated the phenolic content and antioxidant activity of ten fresh and minimally processed lettuce varieties. The phenolic content of selected lettuce samples varied significantly among varieties. Although a higher phenolic content was observed in modern lettuce varieties, when compared to the traditional ones (except for the landrace Francès 219/855), the antioxidant capacity of modern and traditional lettuce varieties was similar. Minimal processing followed by storage for a 7-day period led to an increased phenolic content in varieties Rutilaï RZ, Abago RZ, Maravilla LS044, Francès 219/855, Negre borratger 386/935, and D’hivern LS008, supporting the hypothesis that wounding can induce the accumulation of phenolic compounds in lettuce leaves. For example, the total phenolic content of Francès 219/855 after processing and storage increased from 8.3 to 11.3 mg/100 g (p < 0.05). Accumulation of phenolic compounds after minimal processing was not observed in all the studied samples, suggesting that this effect could be matrix-dependant. The amount of bioaccessible polyphenols was higher after minimal processing and storage. Indeed, the amount of bioaccessible polyphenols after a simulated gastrointestinal digestion of fresh or minimally processed Pelikan lettuce was calculated as 32.6 or 43.3 mg/100 g respectively (p < 0.05), suggesting that the increased amount of polyphenols caused by processing and storage can also lead to a higher amount of bioaccessible phenolic compounds.info:eu-repo/semantics/acceptedVersio

Bioactive hydrolysates from bovine blood globulins: Generation, characterisation, and in silico prediction of toxicity and allergenicity

peer-reviewedTwo protein fractions rich in γ-globulins (FI) and α- and β-globulins (FII) were generated from bovine blood and hydrolysed with the enzyme papain. The generated hydrolysates showed in vitro angiotensin-I-converting enzyme (ACE-I), renin, and dipeptidyl peptidase-IV (DPP-IV) inhibitory activities. A total of 626 and 2246 peptides were identified by LC-MS/MS from the 1 kDa fractions of FI and FII, and the potential toxicity and allergenicity of these peptides were assessed in silico using three independent predictive approaches. All of the peptides identified from the bioactive blood protein fractions FI and FII were predicted to be non-toxic. However, 72 peptides from FI and 492 peptides from FII were identified as potential allergens with at least two predictive approaches. Results suggested that papain hydrolysates of FI and FII contain potential allergenic peptides, and those products containing such hydrolysates should be labelled correctly in line with Food and Consumer legislation – Regulation (EU) No.1169/2011

OPTIMIZATION OF A NEW CULTURE MEDIUM FOR THE LARGE-SCALE PRODUCTION OF PROTEIN-RICH ARTHROSPIRA PLATENSIS (OSCILLATORIALES, CYANOPHYCEAE)

Our aim was to develop a novel medium for the large-scale production of protein-rich Arthrospira with potential applications as a biofertilizer. The novel culture medium, termed as FM-II, was formulated using low-cost commercial chemicals and specifically designed to improve protein production. Both Arthrospira platensis and Arthrospira maxima were produced using FM-II and Arnon medium, which was used as a control. Photosynthetic status of the cells, which was checked by measuring chlorophyll fluorescence, biomass dry weight and protein content, was assessed daily. Arthrospira platensis had higher biomass and protein productivities than A. maxima when cultured in both control and FM-II media. Incorporation of varied micronutrients into FM-II formulation did not improve biomass productivity. Maximum biomass dry weight in FM-II and control medium was 2.9 and 2.5 g · L−1, respectively. Total protein content of the biomass ranged between 55% and 65%, suggesting potential for being used in the development of high-value agricultural products. As some nutrients were discarded unused, the initial content of phosphates and bicarbonates was reduced by 75% and 50%, respectively, without affecting the process productivity. Results reported herein could promote the production and utilization of Arthrospira platensis by significantly reducing productions costs and therefore increasing the feasibility of the process

Identification of bioactive peptides from a papain hydrolysate of bovine serum albumin and assessment of an antihypertensive effect in spontaneously hypertensive rats

peer-reviewedInhibition of angiotensin-I-converting enzyme (ACE-I), renin, and dipeptidyl peptidase-IV (DPP-IV) plays a key role in the treatment of hypertension and type-2 diabetes. The aim of this study was to isolate and characterize novel ACE-I, renin, and DPP-IV inhibitory peptides from a papain hydrolysate of bovine serum albumin (BSA). BSA was obtained from whole bovine blood and hydrolyzed with the food-grade enzyme papain. The generated hydrolysate was further purified using ultrafiltration and high performance liquid chromatography (HPLC), and a number of novel bioactive peptides were identified using de novo peptide sequencing. These included SLR, YY, ER, and FR which inhibited the activity of the enzyme ACE-I by half at a concentration of 0.17±0.02, 0.18±0.04, 0.27±0.01, and 0.42±0.02mM, respectively. In addition, the 1kDa fraction of the papain hydrolysate was assessed for antihypertensive activity in vivo using spontaneously hypertensive rats (SHRs) and reduced systolic blood pressure over a 24h period when compared with the control (p<0.001). Results demonstrated the potential of bovine serum albumin as a source of bioactive peptides with health-promoting properties and potential for use as functional food ingredients

Year-long production of Scenedesmus almeriensis in pilot-scale raceway and thin-layer cascade photobioreactors

Biomass of Scenedesmus almeriensis was produced outdoors for 12 months using three different photobioreactor designs. Optimum dilution rates to achieve the highest biomass productivities were 0.2 day-1 for raceways and 0.3 day-1 for thin-layer reactors. Biomass productivities achieved using thin-layer cascade photobioreactors during the months of higher photosynthetic activity reached 30-35 g/m2·day, higher than those obtained using raceways during the same period: 20-25 g/m2·day. Photosynthetic efficiency was lower in spring/summer when compared to autumn/winter, suggesting that a larger share of the solar energy that reaches the culture in spring/summer is not used for microalgal growth. During summer, culture temperature reached 40 °C in thin-layer photobioreactors, which demonstrates the importance of selecting microalgal strains able to resist these conditions. Photoinhibition was not observed at incident irradiances up to 1600 μE/m2·s. However, dissolved oxygen values were especially high in thin-layer photobioreactors during this time of the year. They reached maximum values of 400% and showed an inhibitory effect on microalgal growth

Consumer knowledge and attitudes towards microalgae as food: The case of Spain

Spanish consumers’ knowledge and attitudes towards microalgae as food were assessed using a specific questionnaire - a total of 3,084 Spanish consumers over 18 years old were considered in the current study. Overall, the questionnaire revealed that there is a huge lack of knowledge on basic aspects of microalgae, especially within the youngest respondents (18-24 years old) and for those aged over 65 years old. Approximately 85% of all respondents scored the statement “There is a big lack of information about microalgae” with either 4 or 5 (using a 5-point hedonic scale), demonstrating that microalgae and their potential applications are unknown to the majority of the Spanish population. Spanish consumers consider microalgae as: (i) sustainable and environmentally friendly, (ii) nutritious and healthy, and (iii) safe, which is of key importance for food products. The main reasons that were given for not consuming microalgae were lack of information available on the product and lack of consuming habit. The current study also demonstrated that increasing consumer’s knowledge on microalgae has the potential to increase consumer choice and market shares of microalgae-enriched products. Results reported herein could be extrapolated to other European countries, although perception and attitudes towards food can vary depending on cultural considerations

Bioactive peptides and carbohydrates from seaweed for food applications: Natural occurrence, isolation, purification, and identification

Macroalgae or seaweed are relative un-explored and promising sources of novel molecules for the food industry including peptides and carbohydrates for their use as functional foods and nutraceuticals. Several algae-derived bioactive compounds have shown a wide range of biological activities both in vitro and in vivo, i.e. antihypertensive and antioxidant, that are strongly associated with the chemical structure of the peptides or carbohydrates. Multiple improvements in the purification and analytical tools to characterize these compounds have been reported in recent years, aiming to gain further insight into the complexity of different molecular structures of bioactive peptides and carbohydrates. This paper discusses the variable composition of algae and the opportunities of the use of this biomass to obtain novel functional bioactive peptides and carbohydrates for functional food applications. The main biological activities of the discovered bioactive peptides and carbohydrates together with the analytical procedures used to purify and characterize multiple compounds are also discussed.Spanish Ministry of Science, Innovation, and Universitie