Determination of para-synephrine and meta-synephrine positional isomers in bitter orange-containing dietary supplements by LC/UV and LC/MS/MS

Dietary supplements that contain bitter orange (Citrus aurantium) fruit as an integrated component have rapidly replaced ephedra-containing dietary supplements for use as weight loss products. However, the safety of bitter orange-containing supplements has been questioned because synephrine, an adrenergic alkaloid and a key component of bitter orange fruit, has potential adverse health effects. Conflicting reports have stated that synephrine exists as the para (p) and/or meta (m) positional isomers in some bitter orange-containing supplements and this is problematic because the p- and m-isomers have distinctly different pharmacological and metabolic activities. Two liquid chromatographic (LC) methods have been developed for the baseline separation and quantitation of p- and m-synephrine in bitter orange-containing supplements. An isocratic LC method that utilizes ultraviolet (UV) absorbance detection and a gradient LC method that utilizes tandem mass spectrometry (MS/MS) detection were optimized for separation of the isomers within a run time of 25 min. Terbutaline was utilized as an internal standard compound in both LC methods. The LC/UV and LC/MS/MS methods demonstrated limits of quantitation (LOQs) for synephrine of ≈30 ng (on-column) and ≈0.02 ng (on-column), respectively, and each method exhibited analytical linearity over three orders of magnitude. Both LC methods were used to evaluate the synephrine levels in a limited selection of commercially available bitter orange-containing supplements. Significantly, m-synephrine was not detected in any of the tested dietary supplements.     

Integrated mass spectrometry approach to profile proanthocyanidins occurring in food supplements: Analysis of Potentilla erecta L. rhizomes

Potentilla erecta (L.) is known for the high concentration of proanthocyanidin oligomers (PAs) in its underground parts. The use of its preparations as food supplements and the lack of chemical–analytical studies concerning with an efficient chromatographic separation procedure for these compounds led us to develop a strategy to profile PAs occurring in this species.     

Dietary supplements and human health: For better or for worse?

Encouraged by the potential health benefits of higher dietary intake of substances with beneficial properties, the use of supplements containing these compounds has increased steadily over recent years. The effects of several of these, many of which are antioxidants, have been supported by data obtained in vitro, in animal models, and often by human studies as well. However, as carefully controlled human supplementation trials have been conducted, questions about the efficacy and safety of these supplements have emerged. In this Educational Paper, three different supplements were selected for consideration of the benefits and risks currently associated with their intake. The selected supplements include β-carotene, selenium, and genistein. The use of each is discussed in the context of preclinical and clinical data that provide evidence for both their use in reducing disease incidence and the possible liabilities that accompany their enhanced consumption. Variables that may influence their impact, such as lifestyle habits, baseline nutritional levels, and genetic makeup are considered and the application of these issues to broader classes of supplements is discussed.     

Valorization of wild strawberry-tree fruits (Arbutus unedo L.) through nutritional assessment and natural production data

Arbutus wild berries have been traditionally collected and appreciated in the Mediterranean region, although it is actually considered an underutilized fruit-tree species. Increasing the scarce knowledge about its nutritional composition and natural production may interest a broad range of scholars, such as ethnobotanists, chemists, nutritionists and anthropologists. The present study aims to provide original data on the nutritional value and the biomass production of wild strawberry-tree fruits, studying the variation of these characteristics in fruits harvested in different years, from two different Spanish areas.Macro and micronutrient composition of mature Arbutus unedo fruits have been analyzed, with particular attention to the content of some bioactive compounds (fiber, vitamin C as ascorbic and dehydroascorbic acids, total phenolics, carotenoids, including lycopene) and the organic acids profile. The contribution to recommended dietary allowances (RDAs) of this exotic fruit has also been calculated. Fruit crop volume per tree has been estimated as well in the wild strawberry-tree populations surveyed to provide a general framework for discussing the agronomic potential of the species.A wide variability in the nutrient composition of strawberry-tree fruits was found which shows that the analysis of many different samples from different origins and seasons are required to provide average reliable data about the chemical composition of wild fruits. From the results obtained, strawberry-tree fruits can be considered a very good source of health promoting compounds as vitamin C and dietary fiber (202.6 mg/100 g and 42.6% minimum contribution to RDAs, respectively). They are also rich in total available carbohydrates, sugars, potassium and secondary metabolites, such as phenolic compounds, being poor in lipids and Na. These results, together with its high production may help to reinforce its consumption, as an alternative to the fruits available in the market or a source of bioactive compounds for dietary supplements or functional foods.     

Citrus paradisi and Citrus sinensis flavonoids: Their influence in the defence mechanism against Penicillium digitatum

Citrus peel is rich in flavanone glycosides and polymethoxyflavones. In view of their importance for industrial application as well as for their pharmacological properties, their content was analyzed in the mature fruits of several Citrus paradisi (grapefruit) and Citrus sinensis (orange) varieties, with a view to select the most interesting for isolation. The results shows that the Star Ruby grapefruit and the Sanguinelli orange stand out for their high contents of naringin and hesperidin, respectively. The presence of the polymethoxyflavones nobiletin, heptamethoxyflavone and tangeretin, could be ascertained in all the grapefruit varieties analysed. Higher polymethoxyflavone levels were recorded in orange, with Valencia Late showing the greatest nobiletin, sinensetin and tangeretin contents and Navelate the highest heptamethoxyflavone levels. An in vitro study revealed that these compounds acted as antifungal agents against Penicillium digitatum, the polymethoxyflavones being more active than the flavanones in this respect. The possible participation of these phenolic compounds in the defence mechanism of Citrus against P. digitatum is discussed.     

Survey of the fatty acid composition of retail milk in the United States including regional and seasonal variations

Consumers are increasingly aware that food components have the potential to influence human health maintenance and disease prevention, and dietary fatty acids (FA) have been of special interest. It has been 25 years since the last survey of US milk FA composition, and during this interval substantial changes in dairy rations have occurred, including increased use of total mixed rations and byproduct feeds as well as the routine use of lipid and FA supplements. Furthermore, analytical procedures have improved allowing greater detail in the routine analysis of FA, especially trans FA. Our objective was to survey US milk fat and determine its FA composition. We obtained samples of fluid milk from 56 milk processing plants across the US every 3 mo for one year to capture seasonal and geographical variations. Processing plants were selected based on the criteria that they represented 50% or more of the fluid milk produced in that area. An overall summary of the milk fat analysis indicated that saturated fatty acids comprised 63.7% of total milk FA with palmitic and stearic acids representing the majority (44.1 and 18.3% of total saturated fatty acids, respectively). Unsaturated fatty acids were 33.2% of total milk FA with oleic acid predominating (71.0% of total unsaturated fatty acids). These values are comparable to those of the previous survey in 1984, considering differences in analytical techniques. Trans FA represented 3.2% of total FA, with vaccenic acid being the major trans isomer (46.5% of total trans FA). Cis-9, trans-11 18:2 conjugated linoleic acid represented 0.55% total milk FA, and the major n-3 FA (linolenic acid, 18:3) composed 0.38%. Analyses for seasonal and regional effects indicated statistical differences for some FA, but these were minor from an overall human nutrition perspective as the FA profile for all samples were numerically similar. Overall, the present study provides a valuable database for current FA composition of US fluid milk, and results demonstrate that the milk fatty acid profile is remarkably consistent across geographic regions and seasons from the perspective of human dietary intake of milk fat.     

An overview of consumer attitudes and beliefs about plant food supplements

The use of dietary supplements is increasing globally and this includes the use of plant food supplements (PFS). A variety of factors may be influencing this increased consumption including the increasing number of older people in society, mistrust in conventional medicine and the perception that natural is healthy. Consumer studies in this area are limited, with a focus on dietary supplements in general, and complicated by the use of certain plant food supplements as herbal medicines. Research indicates that higher use of dietary supplements has been associated with being female, being more educated, having a higher income, being white and being older, however the drivers for consumption of supplements are complex, being influenced by both demographic and health-related factors. The aim of this paper is to provide an overview of current knowledge about the users and the determinants of usage of plant food supplements. With growing consumption of these products, the need for effective risk-benefit assessment becomes ever more important and an insight into who uses these types of products and why is an important starting point for any future science-based decisions made by policy makers, PFS manufacturers and ultimately by consumers themselves.     

Assessing nutritional quality of milk-based sport supplements as determined by furosine

Milk proteins have a strong position in the sport nutrition markets, such as sport supplements for highly trained athletes, apart from bodybuilders. Furosine, a well-known index for the availability of lysine and subsequently of the extent of the Maillard reaction, was evaluated in different common ingredients used for formulation, as well in commercial sport supplements. Furosine content ranged from 2.8 to 1125.7 mg/100 g protein in commercial sport supplements being usually lower in samples containing mainly whey protein isolates or casein, as compared with whey protein concentrates. It is estimated that 0.1–36.7% of the lysine content is not available in this type of products. The use of high quality ingredients for the manufacture of sport supplements reveals important, since it could be the major source of protein intake of certain group of consumers in high or moderate training regime. Furosine is an appropriate indicator to estimate the nutritional quality of sport supplements. A reference value of 70 mg furosine/100 g protein content in dried sport supplements could be set up for controlling the quality of milk-based ingredients used in the formulation. Samples with higher levels are suspected of use of low quality milk-based ingredients or inappropriate storage conditions.     

Genetic and chemical diversity of Eleutherococcus senticosus and molecular identification of Siberian ginseng by PCR-RFLP analysis based on chloroplast trnK intron sequence

Siberian ginseng (SG), the rhizome and root of Eleutherococcus senticosus, has been used as a tonic and anti-fatigue agent in northeastern Asia from ancient time. In recent years, SG has been becoming fairly popular as dietary supplements and health foods worldwide. In order to establish a convenient and sensitive method for authentication, chloroplast trnK intron sequences of 6 Eleutherococcus species were determined and compared. Genetic polymorphism, representing by 14 types of trnK intron sequence, in E. senticosus was observed. However, characteristic nucleotide markers stable within this species enabled clear discrimination of it from other congeners. A PCR-RFLP method was further developed, which was demonstrated to be efficient for authentication of crude drugs as well as health foods. Quantitative evaluation of three main bioactive constituents indicated chemical diversity in E. senticosus collected from northeast China and the results suggested good producing areas of SG. The chemical data clearly revealed that E. sessliflorus was unsuitable to be used as SG.     

Antioxidative effect of compounds isolated from Globularia alypum L. structure-activity relationship

The antioxidant activity of the Globularia alypum phytochemicals were evaluated for their capacity to scavenge the 1,1-diphenyl-2-dipicrylhydrazyl (DPPH°) free radical and some structure-activity relationships were obtained. Assay guided fractionation led to the isolation of syringin, four phenylethanoids, four flavonoids and six iridoids as the main constituents of the extract and their antioxidant activity was determined. The obtained results showed that the activity towards the DPPH° free radical was mainly due to the flavonoid and phenyl ethanoid constituents which were most active free radical scavengers than iridoids. Among the tested flavonoids, 6-hydroxyluteolin glycosides showed the strongest activity, suggesting that the presence of the 6-hydroxyl group was a favourable structural feature of flavonoids with regard to DPPH° scavenging effect. The isolated phenylethanoid glycosides all showed potent antioxidant activity and their capacity to scavenge free DPPH° radical was greater than BHT. Their high antioxidant activity could be attributed to the caffeoyl moieties contained in them, while iridoids showed moderate free radical scavenging activity. The obtained results demonstrated that some of the isolated compounds play an important role for the antioxidant activity of G. alypum and give a scientific basis to the use of this plant in traditional medicine. The hydromethanolic extract of G. alypum could thus be considered as a source of potential antioxidants and will promote the reasonable usage of this plant in food technology and processing as well as for medical use.     

Antibacterial activity produced by Enterococcus spp. isolated from an artisanal Mexican dairy product,Cotija cheese

Several Enterococci were isolated from Cotija cheese, which is a Mexican farmhouse-made product prepared from whole raw milk. No thermal step, neither starter cultures, are used in its manufacturing process. From the isolated strains two were outstanding for their extracellular lytic activity against Staphylococcus aureus, and were identified by 16S rDNA sequencing as Enterococcus faecalis and Enterococcus faecium, respectively. They also showed bacteriolytic activity against other pathogenic bacteria, such as Yersinia enterocolitica, Salmonella enterica Typhimurium and Pseudomonas aeruginosa, as demonstrated by agar diffusion tests. By zymography it was shown that they produced proteins with bacteriolytic activity with molecular masses of 95 and 81 kDa, respectively. Protein identification by LC/ESI–MS/MS showed that they correspond to different enzymes with peptidoglycan hydrolase (PGH) activity of N-acetylglucosaminidase. Two of them were considered as putative enzymes and had not been studied before. Concentrated protein preparations from both strains showed lytic activity on S. aureus growth in liquid culture, as well. Considering that the PGHs studied are produced by lactic bacteria isolated from a dairy product and their spectrum of bacterial inhibition, these enzymes have a potential use in food preservation.     

Antioxidant activities of Sechium edule (Jacq.) Swartz extracts

The antioxidant activities (AA) of Sechium edule extracts were tested by three established in vitro methods, namely reducing power, β-carotene linoleate model and 1,1- diphenyl-2 picrylhydrazyl (DPPH) radical-scavenging. Leaf ethanolic extracts and leaf and seed water extracts showed strong inhibitory activity by β-carotene bleaching (AA values of 90%). Furthermore, these extracts exerted hydrogen-donating ability in the presence of DDPH stable radical (IC₅₀ 2 μg/ml). These extracts also showed strong reducing power by the potassium ferricyanide reduction method. Leaf and seed extracts may be exploited as biopreservatives in food applications as well as for health supplements or functional food, to aleviate oxidative stress.     

Wax Esters of n -3 Polyunsaturated Fatty Acids: A New Stable Formulation as a Potential Food Supplement. 1 — Digestion and Absorption in Rats

Fish oils (FO) and their ethyl ester derivatives (EE) are proposed as rich sources of n -3 polyunsaturated fatty acids (PUFA), in view of their nutritional and therapeutic effects. However, they have drawbacks due to their high degree of susceptibility to oxidation, both during manufacturing and in living organisms. We prepared wax esters (WE) by transesterification of stoichiometric amounts of ethyl esters enriched with n -3 PUFA and long-chain alcohols (18-22 carbon atoms). They are waxy solids, with melting points from 30 to 52 °C, depending on the degree of unsaturation in the acidic and alcoholic moieties of the molecules. We studied their bioavailability in comparison with commercially available products, namely EE and FO, using an animal model (rat). WE have a low degree of susceptibility to oxidation and a high degree of enzymatic hydrolysis in vitro. After an oral load, rats hydrolyse and absorb WE to a greater extent than EE, resulting in significant enrichment of n -3 PUFA in plasma triglycerides. After dietary supplementation with WE (0.15 g/d/rat) for 4 weeks, n -3 PUFA in plasma phospholipid were comparable to those of rats receiving diets supplemented with FO and EE in equimolar concentrations of n -3 PUFA. Body weight, lipid profile and intestinal transit were not affected by 4 weeks' treatment with WE. These formulations offer a potential advantage as food supplements over products in current use, on account of their greater stability.     

Lipase production by solid fermentation of soybean meal with different supplements

The aim of this work was to study the production of extracellular lipases by solid state fermentation in soybean meal with different supplements. Lipase production by two microorganisms, screened by their potential for lipase production, was followed in terms of hydrolytic activity at different pH values(4, 7 and 9). The supplementation of the medium with urea and soybean oil significantly increased the enzyme production for all studied pH and microorganisms. Microorganism Penicillium P58 and P74 showed the possibility of production of different lipases with alkaline and acidic characteristics. In soybean meal supplemented with urea and soybean oil, this microorganism yielded 139.2 and 140.7U lipase/g of dry substrate in 48 h of fermentation, in alkaline and acidic conditions, respectively. Different behavior was observed when the enzyme extract was evaluated in neutral conditions, which yielded 180.0U lipase/g in 72 h. A new promising lipase producer strain was testedon soybean meal with different supplements. The strain produced a lipase with high activities by solid state fermentation of soybean meal supplemented with urea and soybean oil.     

Effect of cell immobilization on heat-induced sublethal injury of Escherichia coli, Salmonella Typhimurium and Listeria innocua

The occurrence of sublethally injured cells in foods poses major public health concerns and is an essential aspect when assessing the microbial response to food preservation strategies, yet there is limited research dealing with its specific implications for mild heating. All available studies so far have been performed in broths colonized by planktonic cells, although their susceptibility to lethal agents has often been reported to be markedly different to the stress tolerance of cell colonies developed in solid foods. In this work, the effect of planktonic and colony growth, as well as the influence of colony density on sublethal injury induced by mild heating of Escherichia coli, Salmonella Typhimurium and Listeria innocua were assessed in food model systems. Detection of injured survivors relied on their inability to form visible colonies on salt-based selective media, which do not affect the growth of healthy cells. Sublethal injury (SI) increased rapidly with shorter exposure times and afterwards, decreased progressively, suggesting a mechanism of cumulative damage triggering lethal instead of SI. Cell arrangement affected the degree of SI, higher values being generally found for gelified systems, although the effect of colony density depended on the target microorganism. This information is essential for optimizing the design of food safety assurance systems.     

New tools to assess toxicity, bioaccessibility and uptake of chemical contaminants in meat and seafood

Meat and seafood chemical contaminants can be very dangerous for human health. The way in which food chemical contaminants are currently controlled is not optimal as the food cooking, processing and eating habits are generally not considered by authorities. The current review discusses the available information related to the toxicity of the most relevant meat and seafood chemical contaminants, their bioaccessibility after cooking or processing, and the implications for human health. In addition, the current in vivo toxicity and alternative tests carried out for testing the effects of food chemical contaminants are illustrated, as well as new detection tools. The use of non-carcinogenic functional cell models, of alternative animal models like zebrafish embryos, and a toxicogenomic approach seem to be the most promising strategy for the toxicity assessment of food chemical contaminants.     

Adulteration of Dietary Supplements by the Illegal Addition of Synthetic Drugs: A Review

In the last few years, the consumption of dietary supplements, especially those having plants as ingredients, has been increasing due to the common idea that they are natural products posing no risks to human health. In the European Union and the United States, dietary supplements are legally considered as foods/special category of foods, thus are not being submitted to any safety assessment prior to their commercialization. Among the issues that can affect safety, adulteration by the illegal addition of pharmaceutical substances or their analogs is of major concern since unscrupulous producers can falsify these products to provide for quick effects and to increase sales. This review discusses the various classes of synthetic drugs most frequently described as being illegally added to dietary supplements marketed for weight loss, muscle building/sport performance and sexual performance enhancement. Information regarding regulation and consumption is also presented. Finally, several conventional and advanced analytical techniques used to detect and identify different adulterants in dietary supplements and therefore also in foods, with particular emphasis on plant food supplements, are critically described. This review demonstrates that dietary supplement adulteration is an emerging food safety problem and that an effective control by food regulatory authorities is needed to safeguard consumers.     

Determination of the content of wax esters in some sea foods and their molecular composition. A comparison with ω-3 enriched wax esters

Wax esters enriched in ω-3 fatty acids have been recently shown to be readily absorbed by rats after dietary supplementation. Wax esters are less prone to oxidation and can be better formulated than liquid ω-3 derivatives. All these characteristics suggest a possible use of wax esters enriched in ω-3 as food supplements. However, some naturally occurring wax esters are defined as scarcely digestible (jojoba oil, spermaceti). On the other hand, wax esters have been found in several sources of marine origin, which can enter normal foodstuff. In order to better understand the digestibility of wax esters, we have analysed some foods from marine sources. The content of triglycerides and wax esters of the foods has been determined. Moreover, wax esters have been analysed for their composition in alcohols and fatty acids. Wax esters have been shown to be a part of the neutral lipid extract of the foods analysed. Their content, if compared with the content in triglycerides, shows striking differences. In the case of two botargo preparations, it has been shown that wax esters are more than 90% of the total neutral lipid extract. The content of fatty acids and alcohols found in the foods analysed is consistent with published data.     

Açaí (Euterpe oleraceae) ‘BRS Pará’: A tropical fruit source of antioxidant dietary fiber and high antioxidant capacity oil

This article reports a study of the concentrations of dietary fiber (DF) and antioxidant capacity in fruits (pulp and oil) of a new açaí (Euterpe oleraceae) cultivar—‘BRS-Pará’, with a view to determine the possibility of using it as a source of antioxidants in functional foods or dietary supplements. Results show that ‘BRS-Pará’ açaí fruits has a high content of DF (71% dry matter) and oil (20.82%) as well as a high antioxidant capacity in both defatted matter and oil. ‘BRS-Pará’ Açaí fruits can be considered as an excellent source of antioxidant dietary fiber. Antioxidant capacity of açaí ‘BRS-Pará’ oil by DPPH assay was higher (EC₅₀ = 646.3 g/g DPPH) than extra virgin olive oil (EC₅₀ = 2057.27 g/g DPPH). These features provide açaí ‘BRS-Pará’ fruits with considerable potential for nutritional and health applications.     

Comparative evaluation of some oenological properties in wine strains of Candida stellata, Candida zemplinina, Saccharomyces uvarum and Saccharomyces cerevisiae

Due to the recent changes in yeast taxonomy, a novel wine-related species Candida zemplinina as well as a “reinstated” species Saccharomyces uvarum have been accepted in addition to Candida stellata, Saccharomyces bayanus and Saccharomyces cerevisiae, and the use of the different taxon names has been inconsistent in the literature of food microbiology. The aim of this work is to make an exact comparison of genetically identified strains of these species, under oenological conditions. Dynamics and some important products of alcoholic fermentation were investigated in laboratory fermentations. The results show that C. zemplinina and C. stellata are similar in their strong fructophilic character. C. stellata produces more glycerol and fare more ethanol, which is comparable with that produced by S. uvarum. Strains of the latter species differed from S. cerevisiae mainly in low acetic acid production and lower ethanol yield. Revision of the oenological traits of these yeasts provides new data for consideration in the control of fermentation, with special regard to botrytized sweet wines, where they are frequently found in mixed population.