Application of green chemistry principles for extraction of phytolipids and phenolic compounds

2291-2296A new era of functional foods has resulted in increased interest in the omega-3 fatty acids, phenolic compounds, and other phytochemicals for preventing and controlling the development of cancer, cardiovascular and other diseases. The focus of the present research is to evaluate the influence of modern sample preparation technologies for extracting crude fat and phytochemicals from plant matrices utilizing fundamental principles of “green” chemistry. Optimization of extraction procedures using modern technologies significantly reduces the quantity of solvent consumed and waste generated during an extraction process. In addition, automation with modern instrumentation reduces exposure to extraction solvents and their vapour. This paper describes extraction of two classes of phytochemicals of extreme polarities, phytolipids (hydrophobic) and phenolics (hydrophilic). It compares five extraction technologies (Butt-tube, soxtec, pressurized liquid extractor, supercritical fluid extractor and Ankom batch extractor) for extraction of crude fat from three soy samples. In addition, this paper outlines a systematic approach for optimization of an extraction procedure for isolation of phytochemicals from different plant matrices using potentially bioactive phenolic compounds as a model. Applications of modern extraction technologies, in conjunction with optimized extraction procedures, will enable chemists and chemical engineers to considerably reduce the quantity of solvents consumed and waste generated during the extraction of bioactive phytochemicals from different plant matrices

Standardization of DPPH, ABTS and FRAP assays with six reference compounds for estimating antioxidant capacity of the tomato extracts using an ultrasound assisted extraction

Comparative calibrating of the antioxidant power of standard compounds, including gallic acid, catechin, Trolox, α-tocopherol, ascorbic acid and BHT were assessed by DPPH, ABTS and FRAP assays to determine total antioxidant activity of ten varieties of tomato extracts using ultrasound assisted extraction. Similar trends in their scavenging activities were found, resulted in the following rank; gallic acid > catechin > trolox > α-tocopherol > ascorbic acid > BHT. Both lipophilic and hydrophilic parts of the extracts were given in these assays in association with using hexane and 50% (v/v) methanol as their efficient extraction solvents, respectively. Their averaged values of the ascorbic acid equivalent antioxidant capacities (AEAC, µmol ascorbic acid/100g DW) were relatively confined in the same ranges of 1341.8-1834.5, 1334.2-2194.8 and 930.7-1734.7 for DPPH, ABTS and FRAP, respectively. In addition, both contents of total phenolics and ascorbic acid known as major deals of antioxidants were also determined, indicating highly existing constituents of the natural antioxidants.

Standardization of DPPH, ABTS and FRAP assays with six reference compounds for estimating antioxidant capacity of the tomato extracts using an ultrasound assisted extraction

Comparative calibrating of the antioxidant power of standard compounds, including gallic acid, catechin, Trolox, α-tocopherol, ascorbic acid and BHT were assessed by DPPH, ABTS and FRAP assays to determine total antioxidant activity of ten varieties of tomato extracts using ultrasound assisted extraction. Similar trends in their scavenging activities were found, resulted in the following rank; gallic acid > catechin > trolox > α-tocopherol > ascorbic acid > BHT. Both lipophilic and hydrophilic parts of the extracts were given in these assays in association with using hexane and 50% (v/v) methanol as their efficient extraction solvents, respectively. Their averaged values of the ascorbic acid equivalent antioxidant capacities (AEAC, µmol ascorbic acid/100g DW) were relatively confined in the same ranges of 1341.8-1834.5, 1334.2-2194.8 and 930.7-1734.7 for DPPH, ABTS and FRAP, respectively. In addition, both contents of total phenolics and ascorbic acid known as major deals of antioxidants were also determined, indicating highly existing constituents of the natural antioxidants.

Extractability of Curcuminoids Is Enhanced with Milk and Aqueous-Alcohol Mixtures

In this study, we evaluated the extractability of three curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) from turmeric powder in several solvents using high-performance liquid chromatography (HPLC) with the diode-array detection method. These solvents include water, milk (homogenized, 2% reduced fat, low fat, fat free, soy, almond, coconut, and milkadamia), and aqueous ethanols (0%, 4%, 10%, 20%, 30%, 40%, 50%, and 100%). Ambient water was able to extract only 0.55 mg/g of curcuminoids, whereas warm water extracted more than four-fold higher amounts (2.42 mg/g). Almond, coconut, and milkadamia milk were able to extract only small amounts of curcuminoids at ambient temperatures (0.01–0.07 mg/g). The extractability of curcuminoids in these milk types did not improve, even in warm conditions (0.08–0.37 mg/g). Whereas dairy and soy milk extracted 6.76–9.75 mg/g of curcuminoids under ambient conditions, their extractability increased significantly in warm conditions by 30–100% higher (11.7–14.9 mg/g). The solubility of curcuminoids also varied remarkably in different proportions of aqueous-alcohol mixtures. With 4% ethanol, only 1.7 mg/g of curcuminoids were extracted, and the amounts improved with the increase in ethanol content up to 50% (32.2 mg/g), while 100% ethanol extracted a similar amount as 50% ethanol (34.2 mg/g). This study suggests that the extractability of curcuminoids from turmeric will be dependent on the type of diets consumed with the turmeric supplements

Pathways for the biosynthesis of polyunsaturated fatty acids

A review

Phenolic Acids Composition of Fruit Extracts of Ber (Ziziphus mauritiana L., var. Golo Lemai)

Fruits of Ziziphus mauritiana L. (ber) are consumed in fresh and dried/processed form in many countries across Asia including Pakistan. In the present study, we analyzed the composition of total phenolic acids (free, soluble-bound and insoluble-bound) from ber fruit extracts by applying a pressurized liquid base hydrolysis extraction (PLBHE) using Dionium cells. Nine phenolic acids (protocatechuic, p-hydroxybenzoic, ferulic, chlorogenic, vanillic, caffeic, vanillin, o- and p-coumaric acids) were extracted, separated, and quantified by HPLC-DAD. Identification of phenolic acids was achieved by comparison of retention times, ultraviolet, and mass spectral data with authentic commercial standards. Results showed that p-coumaric acid (3719 ± 22 µg/g) was the predominant phenolic acid extracted from ber samples. In addition, four phenolic acids, namely p-hydroxybenzoic (2187 ± 71 µg/g), vanillin (2128 ± 20 µg/g), ferulic (2629 ± 96 µg/g), and o-coumaric acids (2569 ± 41 µg/g) were obtained in intermediate amounts from dried Ziziphus mauritiana L. fruit. The total phenolic acids content was determined as 18231 ± 306 µg/g dry matter basis (DMB). This study indicates that ber fruit is a good natural source of phenolic acids and that PLBHE can be used for the assay of phenolic acids

Oxidative Stress and Antioxidants—A Critical Review on In Vitro Antioxidant Assays

Antioxidants have been widely studied in the fields of biology, medicine, food, and nutrition sciences. There has been extensive work on developing assays for foods and biological systems. The scientific communities have well-accepted the effectiveness of endogenous antioxidants generated in the body. However, the health efficacy and the possible action of exogenous dietary antioxidants are still questionable. This may be attributed to several factors, including a lack of basic understanding of the interaction of exogenous antioxidants in the body, the lack of agreement of the different antioxidant assays, and the lack of specificity of the assays, which leads to an inability to relate specific dietary antioxidants to health outcomes. Hence, there is significant doubt regarding the relationship between dietary antioxidants to human health. In this review, we documented the variations in the current methodologies, their mechanisms, and the highly varying values for six common food substrates (fruits, vegetables, processed foods, grains, legumes, milk, and dairy-related products). Finally, we discuss the strengths and weaknesses of the antioxidant assays and examine the challenges in correlating the antioxidant activity of foods to human health

Proteomic and genetic analysis of glycinin subunits of sixteen soybean genotypes

We investigated proteomic and genomic profiles of glycinin, a family of major storage proteins in 16 different soybean genotypes consisting of four groups including wild soybean (Glycine soja), unimproved cultivated soybean landraces from Asia (G. max), ancestors of N. American soybean (G. max), and modern soybean (G. max) genotypes. We observed considerable variation in all five glycinin subunits, G1, G2 G3, G4 and G5 using proteomics and genetic analysis. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) analysis showed that the wild genotypes had a range of 25-29 glycinin protein spots that included both acidic and basic polypeptides followed by the ancestors with 24-28, modern cultivars with 24-25, and landraces with 17-23 protein spots. Overall, the wild genotypes have a higher number of protein spots when compared to the other three genotypes. Major variation was observed in acidic polypeptides of G3, G4 and G5 compared to G1 and G2, and minor variation was observed in basic polypeptides of all subunits. Our data indicated that there are major variations of glycinin subunits between wild and cultivated genotypes rather than within the same groups. Based on Southern blot DNA analysis, we observed genetic polymorphisms in group I genes (G1, G2, and G3) between and within the four genotype groups, but not in group II genes (G4 and G5). This is the first study reporting the comparative analysis of glycinin in a diverse set of soybean genotypes using combined proteomic and genetic analysis