Cholesterol, phytosterol, and tocopherol content of food products and animal tissues

Concentrations of Retinol and α-Tocopherol in Tissue Samples From Anna's Hummingbirds (Calypte anna)

Retinol (vitamin A) and α-tocopherol (vitamin E) concentrations were measured in tissue samples (liver, heart, pectoral muscle, and brain) from Anna's Hummingbirds (Calypte anna). Hummingbirds were after-hatch year birds that were sourced from various rehabilitation centers throughout California. Tissues samples were analyzed using high-performance liquid chromatography (HPLC). Minimum, maximum, mean, standard deviation (SD), and median ppm concentrations were calculated for each vitamin and tissue sample type. A novel analytical method was developed to analyze small mass tissue samples, with the smallest sample mass being 0.05 g for which analysis can be performed. Mean ± standard deviation (SD) concentrations of retinol in hummingbird livers, hearts, and pectoral muscle samples were 269.0 ± 216.9 ppm, 1.8 ± 2.2 ppm, and 0.3 ± 0.1 ppm, respectively. Mean ± SD α-tocopherol concentrations were 6.9 ± 4.6 ppm, 5.5 ± 4.0 ppm, 3.7 ± 2.2 ppm, and 9.1 ± 3.2 ppm for liver, heart, pectoral muscle, and brain samples, respectively. Vitamin concentrations from varying tissue types were compared to determine which were best associated with liver concentrations, the most commonly analyzed tissue for these vitamins. For both retinol and α-tocopherol, heart samples were most strongly associated with the liver samples. The results of this study provide baseline retinol and α-tocopherol concentrations in different tissue types from Anna's hummingbirds. These baseline values may be utilized in conservation efforts to avoid hypervitaminosis and hypovitaminosis of rehabilitated and/or captive hummingbirds by providing guidelines for nutritional targets which could be assessed on post-mortem examinations. Post-mortem examination of birds and measurement of vitamin concentrations in tissues may allow for dietary changes that aid captive hummingbirds.

Occurrence of tocopheryl fatty acid esters in vegetables and their non-digestibility by artificial digestion juices

Tocopheryl fatty acid esters (TFAE) consist of tocopherols esterified to fatty acids, but only little is known about this substance class. In this study, twelve vegetable groups were screened on TFAE and contents of (free) tocopherols and TFAE were determined in red bell pepper, red chili pepper, cucumber and walnut (n = 5, respectively). Intact TFAE were separated by solid phase extraction from free tocopherols and analyzed by GC/MS. Highest TFAE values were determined in chili pepper (4.0–16 mg/100 g fresh weight, FW) and walnut (4.1–12 mg/100 g FW), followed by bell pepper (1.3–1.5 mg/100 g FW) and cucumber (0.06–0.2 mg/100 g FW). Contribution of TFAE to the total tocopherol content ranged from 7–84%. Neither the treatment with artificial digestion juices nor exposure to sunlight showed degradation of TFAE. This substance class might represent a hitherto overlooked storage form for free tocopherols in plants as they occur to be more stable. But as the ester bond in medium chain TFAE seems not to be fissile in the human body, they might not contribute in the same way as free tocopherols to the vitamin E activity of vegetables and might have to be determined separately.

Final report of the amended safety assessment of PEG-5, -10, -16, -25, -30, and -40 soy sterol

PEGs Soy Sterol are polyethylene glycol (PEG) derivatives of soybean oil sterols used in a variety of cosmetic formulations as surfactants and emulsifying agents, skin-conditioning agents, and cleansing and solubilizing agents. When the safety of these ingredients were first reviewed, the available data were insufficient to support safety. New data have since been received and the safety of these ingredients in cosmetics has been substantiated. Current concentration of use ranges from a low of 0.05% in makeup preparations to 2% in moisturizers and several other products. PEGs Soy Sterol are produced by the reaction of the soy sterol hydroxyl with ethylene oxide. In general, ethoxylated fatty acids can contain 1,4-dioxane as a byproduct of ethoxylation. The soy sterols include campesterol, stigmasterol, and beta-sitosterol. The distribution of sterols found in oils derived from common plants is similar, with beta-sitosterol comprising a major component. Impurities include sterol hydrocarbons and cholesterol (4% to 6%) and triterpine alcohols, keto-steroids, and other steroid-like substances (4% to 6%). No pesticide residues were detected. PEGS: Because PEGs are an underlying structure in PEGs Soy Sterols, the previous assessment of PEGs was considered. It is generally recognized that the PEG monomer, ethylene glycol, and certain of its monoalkyl ethers are reproductive and developmental toxins. Given the methods of manufacture of PEGs Soy Sterol, there is no likelihood of ethylene glycol or its alkyl ethers being present. Also, the soybean oil sterol ethers in this ingredient are chemically different from the ethylene glycol alkyl ethers of concern. PEGs are not carcinogenic, although sensitization and nephrotoxicity were observed in burn patients treated with a PEG-based cream. No evidence of systemic toxicity or sensitization was found in studies with intact skin. Plant Phytosterols: Intestinal absorption of ingested plant phytosterols is on the order of 5%, with 95% of the material entering the colon. Absorbed plant phytosterols are transported to the blood. Although there are some data suggesting that sulfates of beta-sitosterol can act as abortifacients in rats and rabbits, other studies of well-characterized plant phytosterols and phytosterol esters demonstrated no effect in an estrogen-binding study, a recombinant yeast assay for estrogen or estrogen-like activity, or a juvenile rat uterotrophic assay for estrogen or estrogen-like activity. In a two-generation reproduction study using rats, plant phytosterol esters in the diet had no effect on any parameter of reproduction or fertility. Subcutaneous injections of beta-sitosterol did reduce sperm concentrations and fertility in rats. Sitosterol inhibited tumor promoting activity of 12-O-tetradecanoylphorbol-13-acetate (TPA) in mice after initiation with 7,12-dimethylbenz[a]anthracene (DMBA), and reduced the tumors produced by N-methylnitrosourea in rats. Phytosterols were not genotoxic in several bacterial, mammalian, and in vitro assay systems. Phytosterols decreased epithelial cell proliferation in the colon of mice and rats, and were cytotoxic for human epidermoid carcinoma of the nasopharynx. PEGs Soy Sterols: The acute oral LD50 in rats of PEG-5-25 Soy Sterol was >10 g/kg. The acute dermal LD50 of a liquid eyeliner containing 2%PEG-5 Soy Sterol was >2 g/kg in rabbits. PEG-5-25 Soy Sterol was not a primary irritant in rabbits when applied undiluted. Undiluted PEG-5 Soy Sterol did not cause sensitization in guinea pigs. PEGs Soy Sterol did not produce ocular toxicity in rabbits. PEG-5 Soy Sterol was negative in the Ames mutagenicity test, with or without metabolic activation. PEG-5 Soy Sterol, at concentrations up to 2%in formulation, did not cause dermal or ocular irritation, dermal sensitization, or photosensitization in clinical studies. Because of the possible presence of 1,4-dioxane reaction product and unreacted ethylene oxide residues, it was considered necessary to use appropriate procedures to remove these from PEGs Soy Sterol before blending them into cosmetic formulations. Based on the systemic toxicity and sensitization seen with PEGs applied to damaged skin, it was recommended that PEGs Soy Sterol should not be used in cosmetic products applied to damaged skin. Although no dermal absorption data were available, oral studies demonstrate that phytosterols and phytosterol esters are not significantly absorbed and do not result in significant systemic exposure. Some small amounts did appear in the ovaries, however. This raises a concern about the potential presence of free phytosterols and beta-Sitosterol, which could have antiestrogenic, antiprogestational, gonadotrophic, antigonadotrophic, and antiandrogenic effects in PEG sterols. These concerns are alleviated by the extensive data showing that well-defined phytosterols and phytosterol esters are not estrogenic and do not pose a hazard to reproduction. Likewise, the absence of impurities in plant phytosterols and phytosterol esters and extensive data demonstrating the absence of any genotoxicity in bacterial and mammalian systems mitigate against the possibility of any carcinogenic effect with those same well-characterized materials. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that the PEGs Soy Sterol are safe as used in cosmetic products.

Nutritional and metabolic studies of distillable fractions from fresh and thermally oxidized corn oil and olive oil

A semisynthetic diet containing 15% by weight of dietary fat was fed to six groups of male wistar rats for 28 days. Two groups received the distillable fraction of fresh corn oil (DCO) or fresh olive oil (DOO), two groups the distallable fractions of the thermally oxidized fats (OCO,OOO), and two groups received the respective fresh fats as controls (FCO, FOO). Substantial changes in the fatty acid composition occurred in the fats upon thermal oxidation. Only the rats that received OOO showed overt symptoms of heated fat toxicity. This was reflected in the histological scores of these animals with the liver sustaining the most numerous and severe lesions. Tissue fatty acid changes of any significance were confined largely to the polar liver lipid of the rats that were fed OCO or OOO. The results of this study would suggest that the relatively greater toxicity of OOO, compared to OCO, may in part be due to the high oleic:linoleic acid ratio of the fresh olive oil and in part to a higher tocopherol content of the corn oil.

Summary of available data for cholesterol in foods and methods for its determination

A search of the literature has been conducted on the cholesterol content of foods and on the methods for its determination. The amount of cholesterol in food is important because of its possible relationship to the onset of atherosclerosis in humans. Cholesterol is present primarily in foods of animal origin. The main sources in the American diet are eggs, poultry, dairy products, fish and seafood, and meat products. Only a few samples of these products have been analyzed. In many cases there is a wide range in cholesterol values for samples analyzed. Much of the research was conducted many years ago. The most commonly used methods were gravimetric or colorimetric. In many cases the samples investigated were not adequately described. Cholesterol was often determined without isolating it from interfering materials. Although some of the cholesterol values reported in the literature appear to be reasonably accurate, there is an urgent need for reinvestigation of the cholesterol content of foods using more recently developed methods of analysis.

Quantitative changes in some unsaponifiable components of soya bean oil due to refining

The effects were studied of the processes of degumming, neutralisation, bleaching and deodorisation on the content and composition of the various fractions of unsaponifiables in soya bean oil. The effect of each of the various technological steps on the decrement of the investigated unsaponifiables in the processed oils was different. When compared with the crude oil, the refined soya bean oil contained less tocopherols (by 31 to 47%), sterols (by 25 to 32%) and squalene (by 15 to 37%). No significant differences were observed in the compositions of the sterol and tocopherol fractions of the crude and refined soya bean oils.

Reduction of blood cholesterol in man

Dietary cholesterol contributes to the development and maintenance of hypercholesteremia in man. Intake of sitosterol prevents cholesterol resorption. This results in lowering of blood cholesterols to a basal endogenous level. Upon cessation of sitosterol intake hemocholesterols return to the original level. Excess supply of plant sterol was required in clinical experiments because the material used contained but 75 to 80 per cent of sitosterol and because of the large amount of endogenous cholesterol which has to be inactivated by the sitosterol, besides exogenous cholesterol.