Magdalena Rafecas

Fatty acid, tocopherol and sterol content of some hazelnut varieties (Corylus avellana L.) harvested in Oregon (USA)

Abstract We analysed the fatty acid, tocopherol and sterol composition of several hazelnut varieties of different geographical origins harvested in Oregon. Monounsaturated and polyunsaturated fatty acids were the most predominant fatty acids in hazelnut oil extracted from samples. A one-way analysis of variance revealed significant differences for fatty acid content between varieties. Discriminant analysis using individual fatty acids as variables revealed that hazelnut samples were grouped according to their origin. α-Tocopherol, campesterol, stigmasterol, β-sitosterol and Δ 5 -avenasterol were predominant in the unsaponifiable lipid fraction of hazelnut samples. A Kruskall Wallis nonparametric test revealed significant differences between hazelnut varieties for α-tocopherol and sterol content. However, no significant differences were found in relation to geographical origin.

Elaidic acid, vaccenic acid and rumenic acid (c9,t11-CLA) determination in human plasma phospholipids and human milk by fast gas chromatography

An efficient fast gas chromatographic method for simultaneous determination of elaidic acid, vaccenic acid and rumenic acid contents in human plasma phospholipids and human milk was optimized and validated. Two capillary columns, RTX-2330 and SP-2560, both of high polarity but with different dimensions (40 m × 0.18 mm I.D. and 0.10 μm film thickness, and 75 m × 0.18 mm I.D. and 0.14 μm film thickness, respectively), were compared for the separation of these fatty acids within a complete fatty acid profile. Separation with the SP-2560 column gave the best results. In comparison with the commonly used 100 m × 0.25 mm × 0.20 μm columns, this new type of fast column allowed the separation of fatty acid methyl esters with the same resolution but in less time, 32.2 min. In addition, separation of the phospholipid fraction in human plasma samples was optimized by using 96-well extraction plates filled with an aminopropyl phase. Recoveries ranged between 95.8% and 103.7%. Intra-assay and inter-assay precision ranged between 0.76% and 8.87%. Application of this method showed that it is a rapid and reliable method for quick and correct identification and quantification of these fatty acids in routine analysis.

High-throughput analysis of lipid hydroperoxides in edible oils and fats using the fluorescent reagent diphenyl-1-pyrenylphosphine.

A fluorometric method for the determination of hydroperoxides (HP) in edible oils and fats using the reagent diphenyl-1-pyrenylphosphine (DPPP) was developed and validated. Two solvent media containing 100% butanol or a mixture of chloroform/methanol (2:1, v/v) can be used to solubilise lipid samples. Regardless of the solvent used to solubilise the sample, the DPPP method was precise, accurate, sensitive and easy to perform. The HP content of 43 oil and fat samples was determined and the results were compared with those obtained by means of the AOCS Official Method for the determination of peroxide value (PV) and the ferrous oxidation-xylenol orange (FOX) method. The proposed method not only correlates well with the PV and FOX methods, but also presents some advantages such as requiring low sample and solvent amounts and being suitable for high-throughput sample analysis.

Improvement of Weight and Body Composition in a Group of Women through a Weight Management Program Using Food Supplements with or without a Hypocaloric Diet

Overweight is an increasing health problem characterised as a higher than normal body weight due to an abnormal increase in body fat. Body weight adequacy is categorized by using body mass index (BMI), however other parameters such as fat mass (FM), waist circumference (Wci) or waist to hip ratio, are relevant. Ideally, body composition should be calculated initially to evaluate changes during a dietary intervention of weight loss. Hunger experience is another parameter to take into account. The aim of this study was to assess the improvement of weight and body composition through the use of food supplements to control hunger, with and without a hypocaloric diet prescription. 252 women who wanted to lose weight were recruited in the program and splitted into two groups and were monitored for 8 weeks. Anthropometric measures (weight, height, body mass index, fat mass, waist and hip circumference) were taken. The mean age was of 36.84±7.29 and most of them were within overweight or obesity values for BMI, FM, Wci and hip circumference. After 8 weeks, both groups got significant results, achieving not only weight loss but also reduction in body mass index, fat mass, and waist and hip circumferences. However, as expected, improvements were better in FS+diet than in FS group. There is a need to tackle overweight and obesity individually, taking into account the personal characteristics of the patient. Food supplements may be useful to manage hunger and professional individualised assessment is critical to succeed.

Anthropometric Characteristics and other Dietary Aspects of a Group of Spanish Women Looking for Weight Loss and Enrolled in a Weight Management Program

Overweight is a health problem characterised as a higher than normal body weight due to an abnormal increase in body fat. Body weight adequacy is categorised using body mass index (BMI), however other parameters as fat mass (FM), waist circumference or waist to hip ratio, are relevant. Ideally, body composition should be calculated initially to evaluate changes during a dietary intervention for weight loss. Hunger experience is another parameter to take into account in order to succeed. The aim was to investigate and describe the characteristics of women seeking weight loss solutions. We organised an open program for people with body excess who wanted to lose weight. 252 women participated and answered to a dietary interview. Anthropometric measures of weight, height, body mass index, body fat, waist and hip circumference were taken. The mean age was of 36.84±7.29 years, and most of them, about 90%, have followed dietary programs for weight loss throughout their lives. They all wanted to lose weight in a range of 3 to 20 kilograms with a mean value of 11.49±6.01 kilograms. 123 women had a hunger profile of satiating behaviour and 129 a snacking one. The mean BMI was within overweight values, and mean fat mass was within obesity values. Waist and hip circumference were higher than normal in most of the participants and excess body weight perception and attitude were different. There is a need to tackle overweight and obesity individually, taking into account personal consciousness and expectancy, anthropometric measures and hunger experience.