Focus on the Protein Fraction of Sports Nutrition Supplements

Increasing awareness of balanced diet benefits is boosting the demand for high-protein food and beverages. Sports supplements are often preferred over traditional protein sources to meet the appropriate dietary intake since they are widely available on the market as stable ready-to-eat products. However, the protein components may vary depending on both sources and processing conditions. The protein fraction of five commercial sports supplements was characterized and compared with that of typical industrial ingredients, i.e., whey protein concentrates and isolates and whey powder. The capillary electrophoresis profiles and the amino acid patterns indicated that, in some cases, the protein was extensively glycosylated and the supplemented amino acids did not correspond to those declared on the label by manufacturers. The evaluation by confocal laser scanning microscopy evidenced the presence of large aggregates mainly enforced by covalent crosslinks. The obtained findings suggest that, beside composition figures, provisions regarding sports supplements should also consider quality aspects, and mandatory batch testing of these products would provide more reliable information to sport dieticians.     

Adsorption of octanoic acid at the water/oil interface

Fats are widely present in a large variety of food and represent the main source of energy for the body. In the current study we investigate the behaviour of fatty acids at liquid–liquid interfaces, mimicking some steps of the very complex digestion process. Octanoic acid is used as an example of middle chain fatty acids. For the oil phase we choose sunflower oil as an industrial product and hexane as pure oil.The influence of the fatty acid concentration and the pH of the aqueous phase on the interfacial tension is determined by profile analyse tensiometry (PAT), which allows to examine the way of adsorption and transition of the fatty acids from one phase to the other. Predominantly, the pH affects the dissociation and thereby the strength of the hydrophilic character of the fatty acid. The adsorption behaviour indicates the different interfacial activity of the studied octanoic acid.     

Highly Valuable Polyunsaturated Fatty Acids from Microalgae: Strategies to Improve Their Yields and Their Potential Exploitation in Aquaculture

Microalgae have a great potential for the production of healthy food and feed supplements. Their ability to convert carbon into high-value compounds and to be cultured in large scale without interfering with crop cultivation makes these photosynthetic microorganisms promising for the sustainable production of lipids. In particular, microalgae represent an alternative source of polyunsaturated fatty acids (PUFAs), whose consumption is related to various health benefits for humans and animals. In recent years, several strategies to improve PUFAs’ production in microalgae have been investigated. Such strategies include selecting the best performing species and strains and the optimization of culturing conditions, with special emphasis on the different cultivation systems and the effect of different abiotic factors on PUFAs’ accumulation in microalgae. Moreover, developments and results obtained through the most modern genetic and metabolic engineering techniques are described, focusing on the strategies that lead to an increased lipid production or an altered PUFAs’ profile. Additionally, we provide an overview of biotechnological applications of PUFAs derived from microalgae as safe and sustainable organisms, such as aquafeed and food ingredients, and of the main techniques (and their related issues) for PUFAs’ extraction and purification from microalgal biomass.     

A rapid and automated low resolution NMR method to analyze oil quality in intact oilseeds

Oilseeds with modified fatty acid profiles have been the genetic alternative for high quality vegetable oil for food and biodiesel applications. They can provide stable, functional oils for the food industry, without the hydrogenation process that produces trans-fatty acid, which has been linked to cardiovascular disease. High yield and high quality oilseeds are also necessary for the success of biodiesel programs, as polyunsatured or saturated fatty acid oil produces biofuel with undesirable properties. In this paper, a rapid and automated low resolution NMR method to select intact oilseeds with a modified fatty acid profile is introduced, based on ¹H transverse relaxation time (T₂). The T₂ weighted NMR signal, obtained by a CPMG pulse sequence and processed by chemometric methods was able to determine the oil quality in intact seeds by its fatty composition, cetane number, iodine value and kinematic viscosity with a correlation coefficient r > 0.9. The automated system has the potential to analyze more than 1000 samples per hour and is a powerful tool to speed up the selection of high quality oilseeds for food and biodiesel applications.     

Capillary electromigration methods for fatty acids determination in vegetable and marine oils: A review

Fatty acids determination is of paramount importance for quality control and suitable labeling of edible oils, required by regulatory agencies in several countries, and fast methods for this determination are worldly desired. This review article aimed to explore the available analytical methods for vegetable and marine oils analyses employing CE, which can be a straightforward and faster alternative than GC methods for fatty acid determination, considering some purposes. CE usually offers the possibility of a rapid analysis with a simple preparation of the sample, without requiring specific columns, which are inherent advantages of the technique. Instrumental conditions and the key points about fatty acids determination employing the technique are highlighted, and the main challenges and perspectives are also approached. Potential use of CE for edible oil analyses has been demonstrated for research and routine, which can be of interest for industries, regulatory agencies, and edible oil researchers. Therefore, we have explored the analytical approaches described in the last decades, intending to spread the interest of CE methods for fatty acid monitoring, label accuracy assessment, and food authenticity evaluation of edible oils.     

Determination of the 1,3- and 2-positional distribution of fatty acids in olive oil triacylglycerols by 13C nuclear magnetic resonance spectroscopy

Linear models were selected from a large data set acquired for Italian olive oil samples by quantitative 13C nuclear magnetic resonance (NMR) spectroscopy with distortionless enhancement by polarization transfer (DEPT). The models were used to determine the composition of the 2 fatty acid pools esterifying the 1,3- and 2-positions of triacylglycerols. The linear models selected proved that the 1,3- and 2-distribution of saturated, oleate, and linoleate chains in olive oil triacylglycerols deviated from the random distribution pattern to an extent that depended on the concentration of the fatty acid in the whole triacylglycerol. To calculate the fatty acid composition of the 1,3- and 2-positions of olive oil triacylglycerols, the equations of the selected linear models were applied to the fatty acid percentages determined by gas chromatography. These data were compared with the values predicted by the computer method (used to determine the theoretical amounts of triacylglycerols), which is based on the 1,3-random-2-random theory of the fatty acid distribution in triacylglycerols. The biggest differences were found in the linoleate chain, which is the chain that deviated the most from a random distribution pattern. The results confirmed that the 1,3-random-2-random distribution theory provides an approximate method for determining the structure of triacylglycerols; however, the linear models calculated by the direct method that applies 13C NMR spectroscopy represent a more precise measurement of the composition of the 2 fatty acid pools esterifying the 1,3- and 2-positions of triacylglycerols.     

Quality Control of Krill Oil by Nuclear Magnetic Resonance (NMR) Spectroscopy: Composition and Detection of Foreign Species

Krill oil is currently among the most highly promoted products in the dietary supplement market, which, due to its high price, can be potentially adulterated with fish species and artificial oil. For a holistic control of krill oil quality, ¹H, ¹³C, and ³¹P nuclear magnetic resonance (NMR) spectroscopies were used. The fatty acid and phospholipid composition as well as secondary ingredients, such as homarine, amino acids, and chitin, were examined. The following phospholipid species were detected: phosphatidylcholine (75–85?mol %), phosphatidylethanolamine (4–7?mol%) and their lyso derivatives 1-lysophosphatidylcholine (1–2?mol%)–2-lysophosphatidylcholine (10–16?mol%) and lysophosphatidylethanolamine (1?mol%). In the -2 position of phospholipids, the content of eicosapentaenoic acid (mean 68.23%; relative standard deviation 2.23%) was twice as high as the content of docosahexaenoic acid (mean 31.77%; relative standard deviation 4.79%). ¹³C NMR spectroscopy was used to distinguish between krill and fish oil-based dietary supplements. The adulteration of krill oil can be detected by fatty acid distribution in the sn-2 triacylglycerol position. The sensitivity of the method is about 10% (w/w) of fish content in blends, which is enough to detect deliberate adulteration. The same methodology can be used to recognize synthetically modified krill oil. The method was successfully applied to 30 commercially available krill and fish oil supplements.     

Convenient TLC for the detection of a herbal ingredient in a food supplement

This study describes a practical and suitable approach to solve a real problem: the analysis of polyherbal products for which some specifications addressing the composition are lacking (e.g. chemical components). It is reported that an analytical procedure to verify the possible presence in a botanical supplement of a plant is not authorised for use in Italy. No reference of chemical standards for the known components of the plant is commercially available. For this reason and because a rapid response was required, more selective chromatographic techniques such as high-performance liquid chromatography, gas chromatography and liquid chromatography-mass spectrometry were excluded and thin layer chromatography was chosen for applying different experimental procedures. The original English label of the product, which is made by a leading US manufacturer and sold online by American and Italian distributors, lists the same herbal ingredients as the Italian label, but with an addition of Eurycoma longifolia Jack, which is not included in the list of plants admitted in supplements compiled by the Italian Ministry of Health. For greater certainty of the result, a high-performance thin layer chromatography method was then applied. On the basis of the results obtained, it was possible to confirm that E. longifolia Jack was not present in the product.     

Low temperature purification method for the determination of abamectin and ivermectin in edible oils by liquid chromatographytandem mass spectrometry

In this study,a method based on low temperature purification(LTP) coupled with liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for the determination of abamectin(ABA) and ivermectin(IVR) in edible oils.ABA and IVR were extracted using conventional liquid-liquid extraction followed by purification via precipitation of interfering fatty components at low temperature without an additional cleanup step.LTP is simple,easy to use,labour-saving and cost effective,and requires reduced amounts of organic solvent.The linear ranges of ABA and IVR were 5-1000 μg/L using matrix-matched standards.Limits of detection(LOD) and limits of quantification(LOQ)were in the range of 0.1-0.4 μg/kg and 0.3-1.3 μg/kg,respectively.The LOQs were below the strictest maximum residue limits established by Codex Alimentarius Commission.Recoveries at three spiked levels of 10,20 and 100 μg/kg in peanut oil,corn oil,olive oil,soybean oil and lard ranged from 71.1%to119.3%with relative standard deviations of 3.2%-10.3%,which were in agreement with those obtained by the solid phase extraction method.The proposed method was utilized in the analysis of 10 edible oil samples from local market and neither ABA nor IVR was detected.As far as we know,this is the first time that LTP is applied to the determination of avermectins in edible oils.     

Rapid isolation,reliable characterization,and water solubility improvement of polymethoxyflavones from cold‐pressed mandarin essential oil

Polymethoxyflavones possess many biological properties, as lipid‐lowering, hypoglycaemic, anti‐inflammatory, antioxidant, and anticancer activities, therefore, they may be employed as nutraceuticals or therapeutic agents. The scarcity of pure polymethoxyflavones on the market as well as their low water solubility limited in vivo studies and the use of polymethoxyflavones as food or pharmaceutical supplements. Since mandarin peels are a rich source of polymethoxyflavones, tangeretin, nobiletin, sinensetin, tetra‐O‐methyl scutellarein, and heptamethoxyflavone were purified from a nonvolatile residue of a cold‐pressed mandarin essential oil using a multidimensional preparative liquid chromatographic system coupled with a photodiode array detector and a single quadrupole mass spectrometer. A new prototype, consisting of a nano‐liquid chromatography system coupled with an electron ionization mass spectrometer, was used for the characterization of the pure isolated molecules. Finally, due to the collection of highly pure nobiletin and tangeretin, the ability of 2‐hydroxypropyl‐β‐cyclodextrin to enhance the water solubility of both polymethoxyflavones was evaluated by phase solubility studies and Job's plot method.     

Downstream Processing of Therapeutic Peptides by Means of Preparative Liquid Chromatography

The market of biomolecules with therapeutic scopes, including peptides, is continuously expanding. The interest towards this class of pharmaceuticals is stimulated by the broad range of bioactivities that peptides can trigger in the human body. The main production methods to obtain peptides are enzymatic hydrolysis, microbial fermentation, recombinant approach and, especially, chemical synthesis. None of these methods, however, produce exclusively the target product. Other species represent impurities that, for safety and pharmaceutical quality reasons, must be removed. The remarkable production volumes of peptide mixtures have generated a strong interest towards the purification procedures, particularly due to their relevant impact on the manufacturing costs. The purification method of choice is mainly preparative liquid chromatography, because of its flexibility, which allows one to choose case-by-case the experimental conditions that most suitably fit that particular purification problem. Different modes of chromatography that can cover almost every separation case are reviewed in this article. Additionally, an outlook to a very recent continuous chromatographic process (namely Multicolumn Countercurrent Solvent Gradient Purification, MCSGP) and future perspectives regarding purification strategies will be considered at the end of this review.     

Quantitation Free Fatty Acid in Perilla Seed Oil by Capillary Gas Chromatography Combined with Column Chromatography

Perilla frutescens is a member of the Lamiaceae family. It is he first group material which are identified as both medicine and food by Health Ministry of China. Recently the high content of α-linolenic in the seed of Perilla had aroused many scientists attention. Perilla seed oil is plant oil sources of the curative and edible value, which contains high content of α-linolenic(more than 50%). The α-linolenic which is a polyunsaturated fatty acid, however, is very easy to be degradation. The product of rancidity and oxidation changes the quality of oil and some degradation products are harmful to human health.     

Lipase-catalyzed production of short-chain acids terpenyl esters of interest to the food industry

The production of low molecular weight esters as flavor compounds by biotechnological processes has a potential interest for the food industry. The use of natural available substrates and enzymes is an essential part of the process design, because the products may obtain natural label. In this study, direct esterification of citronellol and geraniol with short-chain fatty acids catalyzed by free lipase from Mucor miehei was performed with high yields in n-hexane. The effects of the acid:alcohol ratio on the bioconversion rate of increasing chain length esters was investigated. To reach the optimum yield, substrates and enzyme concentration were determined. The inhibiting effects of acid are strongly attenuated by reducing the quantity of acid and increasing the amount of enzyme in media following the optimum values. Improvements have been made to increase the ester purity. The consumption of excess substrate by adding calculated amounts of acid gives a 10% yield enhancement, and leads to 100% pure terpenyl esters. The first steps to a scale-up application were attempted using a reactor that allowed us to produce ester quantities up to 100 cm³. Separation and purification of the products were treated with success, underlining the lipase stability and efficiency under the conditions of this study. The ability to recover the enzyme, and reusing it in bioconversions, plays a major role in reducing the cost of the overall process.     

Solid-State Fermentation of <Emphasis Type="Italic">Mortierella isabellina</Emphasis> for Lipid Production from Soybean Hull

Soybean hull, generated from soybean processing, is a lignocellulosic material with limited industrial applications and little market value. This research is exploring a new application of soybean hull to be converted to fungal lipids for biodiesel production through solid-state fermentation. Mortierella isabellina was selected as the oil producer because of its high lipid content at low C/N ratio. Several cultivation factors were investigated, including moisture content, inoculums size, fungal spore age, and nutrient supplements, in an attempt to enhance the lipid production of the solid-state fermentation process. The results showed that lipid production with the increase of the moisture content and the spore age, while decreased as the size of inoculums increased. Nutrients addition (KH₂PO₄ 1.2 mg and MgSO₄ 0.6 mg/g soybean hull) improved the lipid production. The total final lipid reached 47.9 mg lipid from 1 g soybean hull after the conversion, 3.3-fold higher than initial lipid reserve in the soybean hull. The fatty acid profile analysis indicated that fatty acid content consisted of 30.0% of total lipid, and 80.4% of total fatty acid was C16 and C18. Therefore, lipid production from soybean hull is a possible option to enable soybean hull as a new resource for biodiesel production and to enhance the overall oil production from soybeans.     

The highly efficient purification capacity of rGO-zeolite composites for aged oil in transformer machines

This research attempts to develop an effective oil purification material composite comprised of reduced Graphene Oxide (rGO) and zeolite nanoparticles. The resultant composites have a high specific surface area (310–420 m²/g) and an appropriate average pore size (1.9–4 nm) for transformer oil purification applications. The oil purification capability of the rGO-zeolite composite was evaluated using a static adsorption test. The findings show that as-synthesised materials provide better acidity, breakdown voltage, viscosity, and color than the commercial zeolite material, ZSM-5, and other purification materials reported in the literature. Additionally, according to the purification results, the rGO-zeolite composite shows a better purification behaviour than the composite made of rGO and ZnO nanoparticles in the previous work. Furthermore, compared to virgin oil, the quality of refined oil in this work is practically identical. This result may be explained by the unique properties of the rGO-zeolite composite, such as its high BET specific surface area and the appropriate average pore size for aged oil purification. Furthermore, the homogeneous distribution of zeolite nanoparticles on the rGO flake may increase the residence period for the purification process, improving the purification efficiency of the rGO-zeolite composite.     

The application of reporter gene assays for the detection of endocrine disruptors in sport supplements

The increasing availability and use of sports supplements is of concern as highlighted by a number of studies reporting endocrine disruptor contamination in such products. The health food supplement market, including sport supplements, is growing across the Developed World. Therefore, the need to ensure the quality and safety of sport supplements for the consumer is essential. The development and validation of two reporter gene assays coupled with solid phase sample preparation enabling the detection of estrogenic and androgenic constituents in sport supplements is reported. Both assays were shown to be of high sensitivity with the estrogen and androgen reporter gene assays having an EC(50) of 0.01 ng mL(-1) and 0.16 ng mL(-1) respectively. The developed assays were applied in a survey of 63 sport supplements samples obtained across the Island of Ireland with an additional seven reference samples previously investigated using LC-MS/MS. Androgen and estrogen bio-activity was found in 71% of the investigated samples. Bio-activity profiling was further broken down into agonists, partial agonists and antagonists. Supplements (13) with the strongest estrogenic bio-activity were chosen for further investigation. LC-MS/MS analysis of these samples determined the presence of phytoestrogens in seven of them. Supplements (38) with androgen bio-activity were also selected for further investigation. Androgen agonist bio-activity was detected in 12 supplements, antagonistic bio-activity was detected in 16 and partial antagonistic bio-activity was detected in 10. A further group of supplements (7) did not present androgenic bio-activity when tested alone but enhanced the androgenic agonist bio-activity of dihydrotestosterone when combined. The developed assays offer advantages in detection of known, unknown and low-level mixtures of endocrine disruptors over existing analytical screening techniques. For the detection and identification of constituent hormonally active compounds the combination of biological and physio-chemical techniques is optimal.     

复热食用植物油结构变化的红外吸收光谱分析

利用衰减全反射(ATR)傅立叶红外光谱(FTIRS)法对市售优质品牌的8种植物油(转基因豆油、非转基因豆油、葵花籽油、花生油、玉米油、红花籽油、调和油、橄榄油)未加热及反复高温加热后的红外二阶导数光谱进行比较,发现复热食用油在反复高温加热下会使不饱和脂肪酸亚油酸、亚麻酸的含量降低,饱和脂肪酸棕榈酸和硬脂酸的含量增加;顺式脂肪酸的含量下降,反式脂肪酸的含量明显增加。确定以二阶导数光谱中3 009、988、966 cm-13处特征吸收峰的峰高判定是否为反复加热用油。此方法样品用量少、分析速度快,可从整体上了解油品的质量及成分,并可作为市场复热食用油的快速筛查方法,也可为地沟油检测方法的建立提供理论依据。     

Intra-Laboratory Validation of Alpha-Galactosidase Activity Measurement in Dietary Supplements

Introduction: Alpha-galactosidase (α-Gal) is an enzyme responsible for the hydrolyzation of glycolipids and glycoprotein commonly found in dietary sources. More than 20% of the general population suffers from abdominal pain or discomfort caused by intestinal gas and by indigested or partially digested food residuals. Therefore, α-Gal is used in dietary supplements to reduce intestinal gases and help complex food digestion. Marketed enzyme-containing dietary supplements must be produced in accordance with the Food and Drug Administration (FDA) regulations for Current Good Manufacturing Practice (cGMPs). Aim: in this work we illustrated the process used to develop and validate a spectrophotometric enzymatic assay for α-Gal activity quantification in dietary supplements. Methods: The validation workflow included an initial statistical-phase optimization of materials, reagents, and conditions, and subsequently a comparative study with another fluorimetric assay. A final validation of method performance in terms of specificity, linearity, accuracy, intermediate-precision repeatability, and system precision was then executed. Results and conclusions: The proven method achieved good performance in the quantitative determination of α-Gal activity in commercial food supplements in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals (ICH) guidelines and is suitable as a rapid in-house quality control test.     

Thermal and quality evaluation of vegetable oils used in ruminant feed

Dairies add fat supplements to the diets of small ruminants to increase energy production and consequently the production and quality nutritional and sensorial of the milk. This study investigated the thermal and oxidative stability of babassu, castor, faveleira, and sesame oils by TG/DTA and PDSC. The profile of the fatty oils studied was determined by GC–MS as well as physicochemical characteristics. The thermogravimetric profile of the oils indicated that mass loss was caused by the decomposition or volatility of the triacylglycerides. Faveleira and sesame oils showed a high percentage of polyunsaturated fatty acids, especially C18:2. From a nutritional standpoint, unsaturated oils are more suitable supplements for animals because they promote biochemical changes beneficial to human health.