Alternative oil extraction methods from Echium plantagineum L. seeds using advanced techniques and green solvents

Combination of natural strategies to improve the oxidative stability of echium seed oil

Echium seed oil is an alternative source of omega 3 fatty acids but it is highly susceptible to oxidation. A combination of three natural strategies was proposed in this study aiming to improve the oxidative stability of echium oil obtained by pressing (PO) or solvent extraction (PSO), kept in the storage condition for 180 days or during the consumption for 30 days. Our results showed that the reduction of temperature was sufficient to keep the oil stable during storage for both samples. During the consumption time, the best stability was achieved by adding a mixture of antioxidants, composed of sinapic (500 ppm), ascorbic (250 ppm), and citric (150 ppm) acids, and/or 20% of high oleic sunflower oil. The combined strategies promoted a 34 to 80% reduction of peroxide value and 0 to 85% reduction of malondialdehyde concentrations in the samples, showing to be a feasible and natural alternative to improve the oxidative stability of echium oil. PRACTICAL APPLICATION: Our study successfully applied an optimized combination of simple and low-cost strategies to enhance the chemical stability of echium seed oil. As the use of echium oil expands around the world, the oil industry and final consumers may benefit from our results to increase the oil shelf-life.

Grape (Vitis vinifera L.) Seed Oil: A Functional Food from the Winemaking Industry

Wine production is an ancient human activity that generates several by-products, which include some constituents known for their potential in health care and for their role in the food or cosmetic industries. Any variety of grape (Vitis vinifera L.) contains nutrients and bioactive compounds available from their juice or solid parts. Grape seed extract has demonstrated many activities in disease prevention, such as antioxidant effects, which make it a potential source of nutraceuticals. Grape seed is a remarkable winery industry by-product due to the bioactivity of its constituents. Methods for recovery of oil from grape seeds have evolved to improve both the quantity and quality of the yield. Both the lipophilic and hydrophilic chemicals present in the oil of V. vinifera L. make this wine by-product a source of natural nutraceuticals. Food and non-food industries are becoming novel targets of oil obtained from grape seeds given its various properties. This review focuses on the advantages of grape seed oil intake in our diet regarding its chemical composition in industries not related to wine production and the economic and environmental impact of oil production.

Enzymatic modification to produce health-promoting lipids from fish oil, algae and other new omega-3 sources: A review

Lipases are a versatile class of enzymes that have aroused great interest in the food and pharmaceutical industries due to their ability to modify and synthesize new lipids for functional foods. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have shown important biological functions promoting human health, especially in the development and maintenance of brain function and vision. Lipases allow selective production of functional lipids enriched in omega-3 PUFAs and are unique enzymatic tools to improve the natural composition of lipids and provide specific bioactivities. This review comprises recent research trends on the enzymatic production of bioactive, structured lipids with improved nutritional characteristics, using new enzymatic processing technologies in combination with novel raw materials, including microalgal lipids and new seed oils high in omega-3 fatty acids. An extensive number of lipase applications in the synthesis of health-promoting lipids enriched in omega-3 fatty acids by enzymatic modification is reviewed, considering the main advances in recent years for production of ethyl esters, 2-monoacylglycerols and structured triglycerides and phospholipids with omega-3 fatty acids, in order to achieve bioactive lipids as new foods and drugs.

Separation and Purification of ω-6 Linoleic Acid from Crude Tall Oil

Crude tall oil (CTO) is the third largest by-product at kraft pulp and paper mills. Due the large presence of value-added fatty and resin acids, CTO has a huge valorization potential as a biobased, readily available, non-food, and low-cost biorefinery feedstock. The objective of this work was to present a method for the isolation of high-value linoleic acid (LA), an omega (ω)-6 essential fatty acid, from CTO using a combination of pretreatment, fractionation, and purification techniques. Following the distillation of CTO to separate the tall oil fatty acids (TOFAs) from CTO, LA was isolated and purified from TOFAs by urea complexation (UC) and low-temperature crystallization (LTC) in the temperature range between −7 and −15 °C. The crystallization yield of LA from CTO in that range was 7.8 w/w at 95.2% purity, with 3.8% w/w of ω-6 γ-linolenic acid (GLA) and 1.0% w/w of ω-3 α-linolenic (ALA) present as contaminants. This is the first report on the isolation of LA from CTO. The approach presented here can be applied to recover other valuable fatty acids. Furthermore, once the targeted fatty acid(s) are isolated, the rest of the TOFAs can be utilized for the production of biodiesel, biobased surfactants, or other valuable bioproducts.

Production of conjugated fatty acids: A review of recent advances

Conjugated fatty acids (CFAs) have received a deal of attention due to the increasing understanding of their beneficial physiological effects, especially the anti-cancer effects and metabolism-regulation activities. However, the production of CFAs is generally difficult. Several challenges are the low CFAs content in natural sources, the difficulty to chemically synthesize target CFA isomers in high purity, and the sensitive characteristics of CFAs. In this article, the current technologies to produce CFAs, including physical, chemical, and biotechnical approaches were summarized, with a focus on the conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs) which are the most common investigated CFAs. CFAs usually demonstrate stronger physiological effects than other non-conjugated fatty acids; however, they are more sensitive to heat and oxidation. Consequently, the quality control throughout the entire production process of CFAs is significant. Special attention was given to the micro- or nano-encapsulation which presented as an emerging technique to improve the bioavailability and storage stability of CFAs. The current applications of CFAs and the potential research directions were also discussed.

Optimizing and Comparing Ultrasound- and Microwave-Assisted Extraction Methods Applied to the Extraction of Antioxidant Capsinoids in Peppers

Capsinoids are very similar antioxidant compounds to capsaicinoids, but less irritating, non-pungent and more palatable, and can thus be used in greater concentrations for food applications. To date, three capsinoids (capsiate, dihydrocapsiate, and nordihydrocapsiate) have been isolated from the pepper fruits. Due to its substantial commercial importance, it would be convenient to determine which pepper varieties have a richer content. Ultrasound- (UAE) and microwave- (MAE) assisted extraction have been implemented and analyzed using multivariate statistical methods. Firstly, different solvents were tested individually. The three best solvents were used in a set mixture design, where 42% methanol and 58% ethyl acetate were determined as the optimum combination for UAE, and 100% methanol for MAE. Subsequently, a Box–Behnken experimental design with four variables for both UAE and MAE (time, temperature, pH and sample mass:solvent volume “ratio”) was performed. The sample mass:solvent volume was the most influential variable in UAE; while for MAE no variable was any more influential than the others. Finally, both optimized extraction methods were successfully applied to different varieties of peppers. Besides, to demonstrate the efficiency of both extraction methods, a recovery study was performed. The results prove the potential of both techniques as highly adequate methods for the extraction of capsinoids from peppers.

Assessment of Ultrasound Assisted Extraction as an Alternative Method for the Extraction of Anthocyanins and Total Phenolic Compounds from Maqui Berries (Aristotelia chilensis (Mol.) Stuntz)

Research interest regarding maqui (Aristotelia chilensis) has increased over the last years due to its potential health benefits as one of the most antioxidant-rich berries. Ultrasound-assisted extraction (UAE) is an advanced green, fast, and ecological extraction technique for the production of high quality extracts from natural products, so it has been proposed in this work as an ideal alternative extraction technique for obtaining extracts of high bioactivity from maqui berries. In order to determine the optimal conditions, the extraction variables (percentage of methanol, pH, temperature, ratio “sample mass/volume of solvent”, amplitude, and cycle) were analyzed by a Box-Behnken design, in conjunction with the response surface method. The statistical analysis revealed that the temperature and the percentage of methanol were the most influential variables on the extraction of the total phenolic compounds and total anthocyanins, respectively. The optimal extraction time was determined at 15 min for total phenolic compounds, while it was only 5 min for anthocyanins. The developed methods showed a high precision level with a coefficient of variation of less than 5%. Finally, the new methods were successfully applied to several real samples. Subsequently, the results were compared to those that were obtained in previous experiments by means of microwave assisted extraction (MAE). Similar extraction yields were obtained for phenolic compounds under optimized conditions. However, UAE proved to be slightly more efficient than MAE in the extraction of anthocyanins.

Efficient Semi-Synthesis of Natural δ-( R)-Tocotrienols from a Renewable Vegetal Source

Recent studies have highlighted the biological potential of tocotrienols, a vitamin E subfamily. The major natural sources of tocotrienols are complex mixtures requiring particularly challenging purification processes. The present study describes efficient semi-synthetic strategies toward relevant δ-( R)-tocotrienol derivatives, using as a starting material δ-( R)-garcinoic acid, the major vitamin E derivative isolated from Garcinia kola nuts, a renewable vegetal source.

Effects of lipid extraction on nutritive composition of winged bean (Psophocarpus tetragonolobus), rubber seed (Hevea brasiliensis), and tropical almond (Terminalia catappa)

AIM

This experiment aimed to evaluate the nutritive composition and in vitro rumen fermentability and digestibility of intact and lipid-extracted winged bean, rubber seed, and tropical almond.

MATERIALS AND METHODS

Soybean, winged bean, rubber seed, and tropical almond were subjected to lipid extraction and chemical composition determination. Lipid extraction was performed through solvent extraction by Soxhlet procedure. Non-extracted and extracted samples of these materials were evaluated for in vitro rumen fermentation and digestibility assay using rumen: Buffer mixture. Parameters measured were gas production kinetics, total volatile fatty acid (VFA) concentration, ammonia, in vitro dry matter (IVDMD) and in vitro organic matter digestibility (IVOMD). Data were analyzed by analysis of variance and Duncan's multiple range test.

RESULTS

Soybean, winged bean, rubber seed, and tropical almond contained high amounts of ether extract, i.e., above 20% DM. Crude protein contents of soybean, winged bean, rubber seed, and tropical almond increased by 17.7, 4.7, 55.2, and 126.5% after lipid extraction, respectively. In vitro gas production of intact winged bean was the highest among other materials at various time point intervals (p<0.05), followed by soybean > rubber seed > tropical almond. Extraction of lipid increased in vitro gas production, total VFA concentration, IVDMD, and IVOMD of soybean, winged bean, rubber seed, and tropical almond (p<0.05). After lipid extraction, all feed materials had similar IVDMD and IVOMD values.

CONCLUSION

Lipid extraction improved the nutritional quality of winged bean, rubber seed, and tropical almond.