Burgos-Díaz, C., Gallardo, M., Morales, E., Piornos, J., Marqués, A.M., Rubilar, M. (2016). Utilization of proteins from AluProt-CGNA (a novel protein-rich lupin variety) in the development of oil-in-water (O/W) multilayer emulsion systems. European Journal of Lipid Science. 118;7; 1104-1112.
The formation of multilayered interfaces around oil droplets in oil-in-water (O/W) emulsions provides a novel means of improving the quality and stability of many food products. In this work, a system of O/W emulsions containing lipid droplets stabilized by different ionic biopolymers was developed, and their stability under different environmental stresses was evaluated. The protein isolate from a new lupin variety (AluProt-CGNA) and two polysaccharides—chitosan and xanthan gum—were utilized. AluProt-CGNA protein-stabilized emulsions were unstable to aggregation at pH values around their isoelectric point (pI 4.6) and to all the temperatures and salt concentrations evaluated in this study. However, in the presence of chitosan (0.06 wt%), the droplets showed good stability to aggregation from pH 3 to 6, at 30–90°C and at ≤100 mM NaCl. Adding xanthan gum (0.1 wt%) to the system improved emulsion stability from pH 4 to 7, where no phase separation was observed. This study showed that the stability of O/W emulsions containing protein (AluProt-CGNA)-coated lipid droplets under environmental stresses can be improved by adding certain concentrations of chitosan and xanthan gum. These findings have important implications for the design of encapsulation and delivery systems for lipophilic compounds in the food industries.
Burgos-Díaz C., Piornos, J., Wandersleben, T., Ogura, T., Hernández, X., Rubilar, M. (2016). Emulsifying and foaming properties of different protein fractions obtained from a novel lupin variety AluProt-CGNA® (Lupinus luteus). Journal of Food Science. 81;7; 1699-1706.
The use of vegetable proteins as food ingredient is becoming increasingly important due to their high versatility and environmental acceptability. This work describes a chemical characterization and techno-functional properties (emulsifying and foaming properties) of 3 protein fractions obtained from a protein-rich novel lupin variety, AluProt-CGNA®. This nongenetically modified variety have a great protein content in dehulled seeds (60.6 g protein/100 g, dry matter), which is higher than soybean and other lupin varieties. A simple procedure was utilized to obtain 3 different fractions by using alkali solubilization and isoelectric precipitation. Fractions 1 and 3 were mainly composed of protein and polysaccharides (NNE), whereas fraction 2 was mainly composed by protein (97%, w/w). Fraction 3 presented interesting and potential foaming properties in comparison to the other fractions evaluated in the study. Besides, its solubility, foaming and emulsifying capacity were practically not affected by pH variations. The 3 fractions also presented good emulsion stability, reaching values above a 95%. SDS-PAGE showed that fractions 1 and 2 contained mainly conglutin α, β, and δ, but in different ratios, whereas fraction 3 contained mainly conglutin γ and albumins. The results of this work will provide better understanding for the utilization of each protein fractions as potential ingredients in food industry.
Rubilar, M., Burgos-Díaz, C., Lorenzo J.M. (2016). Chapter 9: Grape Seeds (Vitis Vinifera) and Their Nutritional Value. Grape Seeds: Nutrient Content, Antioxidant Properties and Health Benefits. Nova Science Publishers, Inc. New York, USA. p.p 197-209.
Grape (Vitis vinifera L.) seeds, being a rich source of high-value fatty oil, proteins, phenolic compounds and a wide variety of procyanidins, have received increasing attentions because of their recognised health benefits. Grape seeds are a good source of oil (5.8-16.8%) and protein (7.5-16.7%). Grape seed oil is characterized by lower saturated fatty acid content and higher levels of monounsaturated fatty acids and polyunsaturated fatty acids. Regarding fatty acid profile, linoleic acid (C18:2) is the predominant fatty acid followed by oleic acid (C18:1) and palmitic acid (C16:0). Grape seed oil is also rich in tocopherols, α, β and γ-tocopherols and α and γ-tocotrienols, which are the most powerful natural fat soluble antioxidants, and are invaluable antioxidant sources for human nutrition and healthy diets. Grape seed also presents higher essential amino acid contens (ranged from 19.8 mg/100 g to 48.7 mg/100 g). The results of mineral analysis show that grape seeds contained considerable amount of macro and micro elements. Thus, grape seeds could be used as a food supplement to improve the nutritive value of the human diet.
Labra. R., Rock, J.A., Álvarez, I. (2016), Identifying the key factors of growth in natural resource-driven countries. A look from the knowledge-based economy, Ensayos sobre Política Económica. 34;79; 78-89.
The effect of natural resources (NR) on growth has been a topic widely discussed in the economics literature. The evidence shows a predominant negative impact of this, but this can be neutralized if countries adopt a more knowledge-intensive industrial structure. This paper seeks to explore the key factors for growth in natural resource-driven countries under a knowledge economy perspective, providing new evidence that corroborates how a development path based on NR is plausible when some conditions are present. Performing cluster and panel data analyses, our findings reveal the essential role of openness and Foreign direct investment (FDI) to access foreign technologies as key driving factors. Meanwhile, the case of Chile confirms the importance of intangibles for a country’s growth, and demonstrates that a weak innovation capability can become a serious blockage for sustained progress despite the successful advance in other dimensions.
Burgos-Díaz, C., Wandersleben, T., Marqués, A.M., Rubilar, M. (2016) Multilayer emulsions stabilized by vegetable proteins and polysaccharides. Current Opinion in Colloid & Interface Science. 25; 51-57.
There is great interest in the food, cosmetic and pharmaceutical industry in the use of proteins and polysaccharides as natural hydrocolloids to create novel emulsion systems with improved stability and functionality. For example, the electrostatic interaction between proteins and polysaccharides may be used to form oil-in-water (O/W) emulsions with multilayered interfacial membranes around oil droplets or multilayer emulsions. This type of emulsions have been developed using the layer-by-layer (LbL) technique, which consists of direct adsorption of an oppositely charged polyelectrolyte layer (e.g. polysaccharides) on a primary layer of ionic emulsifiers (e.g. proteins). The polymeric structure and electrical charge of proteins make them a special class of compounds very suitable for its utilization in the LbL technique. In recent years, the utilization of proteins as emulsifiers in food and pharmaceutical industry has been turning towards plants as a preferred alternative to animal-based sources. This article reviews the current understanding of the utilization of different vegetable proteins as emulsifier in order to stabilize O/W multilayer emulsion systems. Additionally, it highlights some potential applications of the multilayer emulsion technology in the industry, for improving the stability of emulsions to environmental stresses and for developing controlled or triggered release systems.
Piornos, J.A., Burgos-Díaz, C., Morales, E., Rubilar, M., Acevedo, F. (2016). Highly efficient encapsulation of linseed oil into alginate/lupin protein beads: Optimization of the emulsion formulation. Food Hydrocolloids 63; 139-148.
Encapsulation of linseed oil into high oil content alginate beads has appeared as a potential solution to delay oxidation of this highly unsaturated oil. Additionally, the use of vegetable protein as emulsifier is used in order to enhance the stability of the emulsion and thus the encapsulation efficiency (EE). The aim of this work was to optimize the emulsion formulation in order to maximize EE in dried beads. The effect of alginate (X1: 10–45 g/L) and lupin protein concentrations (X2: 10–50 g/L) in the aqueous phase and oil/water ratio (X3: 15–60 mL/100 mL) on EE, as well as on the oil content, was evaluated by a central composite experimental design (23). The mathematical model showed a great dependence of the studied variables and EE, demonstrating that high alginate and protein concentrations were desirable. By using the optimal formulation, spherical beads of approximately 1.80 mm were obtained. Actual EE (98.30%) for optimal oven dried beads was found to be close to the predicted value (100.88%). Moreover, the optimal beads contained 66.37% of linseed oil, being the most successfully delivered in in vitrodigestive conditions. The stability of encapsulated oil against heat treatments (50–75 °C, 24 h) was higher than free linseed oil, demonstrating the effectiveness of the encapsulating system. Based on the results obtained, the encapsulating system used in this study is suitable for unstable oils for food or nutraceutical purposes.