Influence of used frying oil quality and natural tocopherol content on oxidative stability of fried potatoes

Sunflower oil (SO) and high-oleic sunflower oil (HOSO) were used to prepare fried potatoes by either discontinuous or continuous laboratory frying. Fried potatoes that had been fried in oils of differing quality were stored at 60 degrees C for up to 30 d and evaluated for polar compounds, polymers, peroxide value, oil stability index, and alpha-tocopherol content. Results obtained through the various methods applied were consistent and indicated that the length of the induction period could not be explained only on the basis of the degree of unsaturation or polar compound levels in fried potatoes before storage. alpha-Tocopherol content also had a significant influence as potatoes fried in HOSO, with 16% polar compounds and only 10 mg/kg alpha-tocopherol at the starting point of storage, were oxidized more rapidly than potatoes fried in SO with a comparatively higher degradation level, 19% polar compounds, and 100 mg/kg alpha-tocopherol.

Vegetables biofortified with iodine: chemical, agronomic and qualitative aspects of raw and fried potatoes

Iodine is an essential microelement for human health because it is a constituent of the thyroid hormones that regulate growth and development of the organism. Iodine Deficiency Disorders (IDDs) are believed to be one of the commonest preventable human health problems in the world today, according to the World Health Organization: that diseases include endemic goiter, cretinism and fetal abnormalities, among others, and they are caused by lack of iodine in the diet, that is the main source of iodine. Since iodine intake from food is not enough respect to human needs, this can be remedied through dietary diversification, mineral supplementation, food fortification, or increasing the concentration and/or bioavailability of mineral elements in the edible portions of crops through agricultural intervention or genetic selection (biofortification). The introduction of iodized salt is a strategy widely used and accepted to eradicate iodine deficiency, because it is an inexpensive source of stable iodine. Since the intake of salt, though iodized, must still be limited according to the risk of cardiovascular disease, so the increase of iodine content in plants for the production of functional foods is representing a field of study of particular interest and a potential market. In Italy potatoes enriched with iodine are produced by a patented procedure of agronomic biofortification for the fresh market since several years, furthermore they are recently accepted and recommended by Italian Thyroid Association, as an alternative source of iodine. Researches performed during the PhD course intended to characterize this innovative vegetables products, focusing the attention on different aspects, such as chemistry, agriculture, and quality of fresh and fried potatoes. For this purpose, lipid fraction of raw material was firstly investigated, in order to assess whether the presence of iodine in plant metabolism can affect fatty acid or sterol biosynthesis, according to the hypothesis that iodine can be bounded to polyunsaturated fatty acids of cell membranes, protecting them from peroxydation; phytosterols of plant sterol are also studied because their importance in reducing serum cholesterol, especially in potato plant sterols are also involved in synthesis of glycoalkaloid, a family of steroidal toxic secondary metabolites present in plants of the Solanaceae family. To achieve this goal chromatographic analytical techniques were employed to identify and quantify fatty acids and sterols profile of common and iodine enriched row potatoes. Another aim of the project was to evaluate the effects of frying on the quality of iodine-enriched and common potatoes. Since iodine-enriched potatoes are nowadays produced only for the fresh market, preliminary trials of cultivation under controlled environment were carried out to verify if potato varieties suitable for processing were able to absorb and accumulate iodine in the tuber. In a successive phase, these varieties were grown in the field, to evaluate their potential productivity and quality at harvest and after storage. The best potato variety to be destined for processing purposes, was finally subjected to repeated frying cycles; the effects of lipid oxidation on the composition and quality of both potatoes and frying oil bath were evaluated by chromatographic and spectrophotometric analytical techniques. Special attention were paid on volatile compounds of fried potatoes.

Food patterns associated with blood lipids are predictive of coronary heart disease : the Whitehall II study

Analysis of the epidemiological effects of overall dietary patterns offers an alternative approach to the investigation of the role of diet in CHD. We analysed the role of blood lipid-related dietary patterns using a two-step method to confirm the prospective association of dietary pattern with incident CHD. Analysis is based on 7314 participants of the Whitehall II study. Dietary intake was measured using a 127-item FFQ. Reduced rank regression (RRR) was used to derive dietary pattern scores using baseline serum total and HDL-cholesterol, and TAG levels as dependent variables. Cox proportional hazard regression was used to confirm the association between dietary patterns and incident CHD (n 243) over 15 years of follow-up. Increased CHD risk (hazard ratio (HR) for top quartile: 2·01 (95 % CI 1·41, 2·85) adjusted for age, sex, ethnicity and energy misreporting) was observed with a diet characterised by high consumption of white bread, fried potatoes, sugar in tea and coffee, burgers and sausages, soft drinks, and low consumption of French dressing and vegetables. The diet-CHD relationship was attenuated after adjustment for employment grade and health behaviours (HR for top quartile: 1·81; 95 % CI 1·26, 2·62), and further adjustment for blood pressure and BMI (HR for top quartile: 1·57; 95 % CI 1·08, 2·27). Dietary patterns are associated with serum lipids and predict CHD risk after adjustment for confounders. RRR identifies dietary patterns using prior knowledge and focuses on the pathways through which diet may influence disease. The present study adds to the evidence that diet is an important risk factor for CHD.

Nutrient and core and non-core food intake of Australian schoolchildren differs on school days compared to non-school days.

Overall the diets of Australian schoolchildren are suboptimal, but differences in nutrient and food intake on school versus non-school days have not been assessed. The aim of this study was to examine differences in nutrient and core and non-core food intake on school days versus non-school days in Australian schoolchildren aged 6-16 years. Cross-sectional analysis of the 2007 Australian Children's Nutrition and Physical Activity Survey. Dietary intake was assessed via one 24-h dietary recall. A school day was defined as Monday-Friday, a non-school day included Saturday, Sunday and public/school holidays. Independent t-tests and χ(2) tests were used to assess differences in continuous and categorical variables, respectively. Multiple linear and logistic regression was used to adjust for confounders. Forty-eight per cent of recalls were completed on a non-school day. On non-school days primary schoolchildren aged 6-11 years (n = 1334) and secondary schoolchildren aged 12-16 years (n = 1362) had significantly higher absolute intakes of sugars, total fat and saturated fat (all P < 0.05). In addition the energy density of foods consumed was greater (P < 0.001), but there was no difference in the energy density of fluids. The sodium density of the diet did not differ across day types. On non-school days, total core food intake was ~30% higher and children were more likely to consume sugar-sweetened beverages, fried potatoes and take-away pizzas and burgers (all P < 0.05). Important differences in the intake of sugar, total fat, and saturated fat and noncore foods exist on non-school days compared to school days in Australian schoolchildren. To improve the diets of schoolchildren there is scope for strategies that target non-school day eating practices.

Influência dos tipos de óleos e tempos de fritura na perda de umidade e absorção de óleo em batatas fritas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expression patterns of vascular-specific promoters RolC and Sh in transgenic potatoes and their use in engineering PLRV-resistant plants

The expression patterns of GUS fusion constructs driven by the Agrobacterium rhizogenes RolC and the maize Sh (Shrunken: sucrose synthase-1) promoters were examined in transgenic potatoes (cv. Atlantic). RolC drove high-level gene expression in phloem tissue, bundle sheath cells and vascular parenchyma, but not in xylem or non-vascular tissues. Sh expression was exclusively confined to phloem tissue. Potato leafroll luteovirus (PLRV) replicates only in phloem tissues, and we show that when RolC is used to drive expression of the PLRV coat protein gene, virus-resistant lines can be obtained. In contrast, no significant resistance was observed when the Sh promoter was used.

Are lemons really hot potatoes?

We model the hazard rate for car ownership spells. Our model allows us to distinguish among different types of adverse selection effects by observing the type of unobserved heterogeneity across owners of the same car. Our empirical results strongly suggest that there is a lemons effect because there is significant unobserved heterogeneity. However, they also suggest that the lemons effect is caused by the first owner rather than the manufacturer. Had the manufacturer created the lemon, the unobserved heterogeneity would be positively correlated over all owners of a given car. Instead we observe a negative correlation between the unobserved heterogeneity term for the first owner and the unobserved heterogeneity term for subsequent owners. © 2008 Elsevier B.V. All rights reserved.

Carrying coal and loading potatoes; Juedische Winterhilfe der Juedische Gemeinde; Berlin Jewish Institutions

"88000 Ztr. Kohlen im Werte von 120000 Mark"

Yellow (Perca flavescens) and Eurasian (P. fluviatilis) perch distinguished in fried fish samples by DNA analysis

DNA techniques are increasingly used as diagnostic tools in many fields and venues. In particular, a relatively new application is its use as a check for proper advertisement in markets and on restaurant menus. The identification of fish from markets and restaurants is a growing problem because economic practices often render it cost-effective to substitute one species for another. DNA sequences that are diagnostic for many commercially important fishes are now documented on public databases, such as the National Center for Biotechnology Information’s (NCBI) GenBank.1 It is now possible for most genetics laboratories to identify the species from which a tissue sample was taken without sequencing all the possible taxa it might represent.

Comparison of flavor compounds of potato chips fried in palmolein and silicone fluid

The importance of the frying oil as a heat-transfer medium and as a source of flavor precursors for the formation of potato chip flavor was investigated. Potato slices were fried in palmolein or silicone fluid, and the volatile flavor compounds of the resulting chips were isolated onto Tenax and analyzed by gas chromatography-mass spectrometry. Although the heat-transfer coefficients of the oils did not differ significantly, their temperature profiles during frying were different, probably due to greater turbulence on placing potato slices in palmolein, leading to more efficient heat transfer. Levels of Strecker aldehydes and sulfides in chips fried in the two media were not significantly different, but levels of pyrazines were significantly higher in palmolein-fried chips. Amounts of 2,4-decadienal were also significantly higher in palmolein-fried chips, but there was no significant difference in hexanal levels between the samples.

Formation of Strecker aldehydes and pyrazines in a fried potato model system

Sugars and amino acids were removed from potato slices by soaking in water and ethanol. They were then infused with various combinations of sugars (glucose and/or fructose) and amino acids (asparagine, glutamine, leucine, isoleucine, phenylalanine, and/or methionine) and fried. Volatile compounds were trapped onto Tenax prior to gas chromatography-mass spectrometry. Relative amounts of compounds (relative to the internal standard) and relative yields (per mole of amino acid infused into the slices) were determined. Amounts of 10 pyrazines, 4 Strecker aldehydes, and 4 other compounds were monitored. Relative amounts and relative yields of compounds varied according to the composition of the system. For the single amino acid-glucose systems, leucine gave the highest relative amount and relative yield of its Strecker aldehyde. Asparagine and phenylalanine gave the highest total relative amount and total relative Yield, respectively, of pyrazines. In the system containing all of the amino acids and glucose, the relative amount of 3-methylbutanal was higher, whereas the amounts of the other monitored Strecker aldehydes were lower. Most of the relative amounts of individual pyrazines were lower compared to the glucose-asparagine system, whereas the total relative yield of pyrazines was lower, compared to all of the single amino acid-glucose mixtures. Addition of fructose to the mixed amino acid-glucose model system generated Strecker aldehydes and pyrazines in ratios that were more similar to those of untreated potato chips than to those from the same system but without fructose. Both the sugars and the amino acids present in potato are crucial to the development of flavor compounds in fried potato slices.