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

Optimisation of the pH and boiling conditions needed to obtain improved foaming and emulsifying properties of chickpea aquafaba using a response surface methodology

Chickpea cooking water, also known as aquafaba, generated in our homes is generally discarded as waste. However, this valuable resource contains high quantities of proteins with excellent technofunctional properties. The current paper aimed at optimising the pH and the cooking conditions needed to improve the foaming and emulsifying capacity of aquafaba, as well as the stability of the generated foams and emulsions using a response surface methodology. In general, lowering the pH of the aquafaba using lemon juice and decreasing the chickpea:water ratio during boiling resulted in increased functional properties. The validation tests carried out confirmed the overall adequacy of the response surface models in predicting the functionality of the aquafaba. Moreover, the chickpea cooking water obtained using the optimised conditions was used to develop meringues and mayonnaises, which were compared to those obtained using egg proteins.info:eu-repo/semantics/acceptedVersio

Bioaccessibility, physicochemical, sensorial, and nutritional characteristics of bread containing broccoli co‐products

The effects of the inclusion of industrial broccoli co‐products namely stalks and leaves into bread on physicochemical and nutritional properties were evaluated. Incorporation of powdered broccoli co‐products at a concentration of 2% (w/w) into bread formulations resulted in decreased weight and specific volumes when compared to the control (p < 0.05). Broccoli‐containing breads showed an increased green hue and a higher crust and crumb color intensity (p < 0.05). Incorporation of broccoli co‐products into bread formulations significantly increased the total phenolic content and antioxidant capacity of the breads (p < 0.05). The overall acceptance and appearance of the breads were not affected by broccoli incorporation. The phenolic content and antioxidant capacity of the three formulations increased after the gastric and intestinal phases of digestion when compared to the initial stage, measured from a methanol:water extract (p < 0.05). Results obtained herein could open novel commercial opportunities for food processors and reduce the amount of food discarded as waste.This work was supported by the CERCA Programme of Generalitat de Catalunya. T. Lafarga is in receipt of Juan de la Cierva contract awarded by the Spanish Ministry of Economy and Competitiveness (FJCI-2016-29541). I. Aguiló-Aguayo thanks the Spanish Ministry of Economy and Competitiveness and the European Social Fund for the Postdoctoral Senior Grant Ramon y Cajal (RYC-2016-19949). Authors thank Congelados de Navarra S.A.U (Navarra, Spain) for kindly providing broccoli processing co-products

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

Bioaccessibility and antioxidant activity of phenolic compounds in cooked pulses

The aim of this study was to evaluate the bioaccessibility of polyphenols and antioxidant activity in cooked pulses and to study the effect of cooking on their total phenolic content (TPC) and antioxidant capacity. Cooked faba beans showed the highest TPC, followed by soybeans and lentils or peas. TPC ranged from 10.4 ± 0.2 to 52.9 ± 0.3 mg/100 g and was positively correlated with antioxidant activity. Cooking resulted in increased TPC and antioxidant activity of the methanolic extracts, caused by cell disruption and improved extraction of polyphenols. Although polyphenols were lost in the cooking water, boiled legumes had more polyphenols than those resulting cooking broths. In vitro gastrointestinal digestion resulted in increased TPC and antioxidant capacity of the extracts. Soybeans showed the highest amount of bioaccessible polyphenols. The release of phenolics from cooked legumes was mainly achieved during the intestinal phase. Literature data may underestimate the TPC and antioxidant capacity of pulses.info:eu-repo/semantics/acceptedVersio

Effect of ultrasound processing on the bioaccessibility of phenolic compounds and antioxidant capacity of selected vegetables

Ultrasound processing can result in cell wall disruption, facilitating the release of the cellular content. Therefore, we hypothesized that sonication of vegetables could be used as a pre-treatment to increase the bioaccessibility of phenolic and antioxidant compounds. Overall, sonication (40 kHz, 250 W, 4 °C, 20 min) did not affect the main physicochemical parameters of tomato, lettuce, zucchini, and green and red pepper (p < 0.05). The polyphenolic content and antioxidant activity of digestive enzymatic extracts was higher than that of water:methanol extracts (p < 0.05). In addition, sonication resulted in increased bioaccessibility of phenolic compounds in lettuce and green pepper (p < 0.05), while no effect was observed for tomato, red pepper, and zucchini samples suggesting a matrix-dependent effect. The amount of phenolic compounds and antioxidants released by vegetables during a simulated gastrointestinal digestion may be higher than the one that can be expected from measurements in usual aqueous-organic extracts.info:eu-repo/semantics/acceptedVersio

Potential of the microalgae Nannochloropsis and Tetraselmis for being used as innovative ingredients in baked goods

The potential use of the microalgae species Tetraselmis and Nannochloropsis was investigated for the production of functional breads and crackers. Optimum flour substitution levels were 2.5% for baked crackers and 1.0 or 2.0% for breads containing Nannochloropsis or Tetraselmis, respectively. No major differences were observed in the physicochemical properties of the end products besides an expected darker and greener colour. Microalgae incorporation led to increased phenolic content and in vitro antioxidant capacity in both matrices. For example, the total phenolic content of crackers increased from 24.6 ± 1.5 mg/100 g in the control to 32.4 ± 0.4 or 34.2 ± 1.0 mg/100 g in crackers containing Tetraselmis or Nannochloropsis, respectively. The amount of bioaccessible polyphenols after a simulated gastrointestinal digestion was also higher in microalgae-containing goods than in the controls. Sensory evaluation showed that microalgae-containing products were competitive with the controls with the added advantage of having an improved nutritional value and a "trendy" ingredient. Moreover, microalgae-containing products showed an increased emission of some volatile compounds such as p-cymene and (Z)-2-heptenal, which are responsible for fresh, citrus, terpenic, woody, and spicy or fatty, oily, and fruity odours, respectively.This work was supported by the CERCA Programme of Generalitat de Catalunya. T. Lafarga (FJCI-2016-29541) and I. Aguiló-Aguayo (RYC-2016-19949) thank the Spanish Ministry of Economy, Industry, and Competitiveness. All authors thank Fundación Cajamar (Almería, Spain) for kindly providing with the microalgal biomass

Production of Scenedesmus almeriensis Using Pilot-Scale Raceway Reactors Located inside a Greenhouse

The microalga S. almeriensis was produced in spring and summer using 80 m2 raceway reactors located inside a greenhouse in Almería, Spain. This microalga was selected because it is a fast-growing and robust strain with potential applications in the production of functional foods and feeds or as a high-value agricultural biostimulant. Overall, the biomass productivity obtained in summer was 24.9 ± 0.9 g·m−2·day−1. This value was higher than that obtained in spring, with an average value of 21.4 ± 1.3 g·m−2·day−1 (p < 0.05). The Fv/Fm value of the cultures at the stationary phase was comparable and around 0.6, which is the optimum of this strain. No major differences in the macromolecular composition of the biomass were observed between seasons, with an average protein, lipid, ash, and carbohydrate content of 37.9, 4.6, 10.8, and 46.7%, respectively. The data reported herein were used to validate a previously described model. The differences between the experimental and the predicted biomass productivities were below 5% in spring and 8% in summer, although a larger dataset is needed to validate the model. Overall, results supported the robustness of the selected strain and its utilisation in different industrial sectors

Effect of microalgae incorporation on the physicochemical, nutritional, and sensorial properties of an innovative broccoli soup

The aim of this paper was to develop broccoli soups enriched in Spirulina sp., Chlorella sp., or Tetraselmis sp., at concentrations ranging from 0.5 to 2.0% (w/v), and to assess the effect of microalgae incorporation on their quality and acceptance. Incorporation of freeze-dried microalgae biomass into the broccoli soup resulted in lower L* values, especially after incorporation of Spirulina sp. and Chlorella sp. Microalgae incorporation also led to an increased content of polyphenols and to a higher antioxidant capacity. Microalgae-containing soups showed a higher amount of bioaccessible polyphenols, calculated after a simulated gastrointestinal digestion (ranging between 32.9 ± 1.1 and 45.6 ± 0.5 mg/100 mL). The acceptability index of soups formulated using lower microalgae concentrations was over 70% suggesting that the soups would be well accepted. Indeed, the purchase intention of the soups containing microalgae at 0.5% (w/v) ranged between 3.4 and 4.1 (assessed using a 5-point hedonic scale).info:eu-repo/semantics/acceptedVersio