Anna Maija Lampi

Changes in chemical composition of pumpkin seeds during the roasting process for production of pumpkin seed oil. (Part 1: non-volatile compounds)

Abstract Pumpkin seed oil is a common salad oil in Austria. It is not only of interest because of its typical taste but also because of its potential in curing prostate disease. Besides the fatty acids, the micronutrients, which comprise vitamin E, phytosterols and lignans, are of special interest. Since the seeds are roasted before pressing of the oil, changes occur in the composition of the fatty acids and micronutrients. The oxidation-sensitive linoleic acid decreases from 54.6 to 54.2% whereas the concentrations of the vitamin E isomers show a decrease during the first 40 min of about 30% followed by an increase during the last 20 min to about the same level as at the beginning of the roasting process. The concentrations of α-tocopherol and γ-tocopherol in the fresh dried seeds are 37.5 and 383 μg/g, respectively. The concentration of the tocotrienols is about one third of the corresponding tocopherols. The initial concentration of the total sterols (1710 μg/g) increases to 1930 μg/g. The increases of the sterols and vitamin E during the roasting process could be attributed to the changes of the seed meal, since at the end of the roasting the oil emerges from the seeds resulting in altered chemical behaviour of the extraction process. Secoisolariciresinol, which is only detectable at the beginning with a concentration of 3.8 μg/g, is destroyed after 20 min.

Estimation of plant sterol and cholesterol intake in Finland: quality of new values and their effect on intake

The Finnish national food composition database Fineli was updated with recent analytical values for plant sterols (PS) (sitosterol, campesterol, stigmasterol, avenasterol, brassicasterols and stanols) and cholesterol. The quality of the new analytical data was assessed. The aims of the present study were: (1) to compare the effect of old and new database values on PS and cholesterol intakes based on average per capita food consumption data; (2) to estimate the current intake and major sources of these compounds in various population groups according to the national FINDIET 1997 survey data. The intake of total PS was 305 mg/d for men and 237 mg/d for women. The respective intakes for cholesterol were 284 mg/d and 201 mg/d. Women had a higher density of PS in their diets than men, whereas the cholesterol density in the diets did not differ between genders. Cereals, margarine, vegetables and vegetable oils were the main food sources of PS. Meat, meat products and eggs were the main sources of cholesterol. A 9 % greater PS intake estimate was obtained with the new PS database compared with the old PS database, probably due to minor methodological differences between the new and old analyses. Notable changes in analytical methods suggest a lower value (-19 %) for cholesterol intake calculated from the new database compared with the old one. We conclude that researchers can have confidence in the new values for PS and cholesterol, because systematic evaluation of the new analytical values showed them to be of high quality.

The HEALTHGRAIN Wheat Diversity Screen: Effects of Genotype and Environment on Phytochemicals and Dietary Fiber Components

Analysis of the contents of bioactive components (tocols, sterols, alkylresorcinols, folates, phenolic acids, and fiber components) in 26 wheat cultivars grown in six site x year combinations showed that the extent of variation due to variety and environment differed significantly between components. The total contents of tocols, sterols, and arabinoxylan fiber were highly heritable and hence an appropriate target for plant breeding. However, significant correlations between the contents of bioactive components and environmental factors (precipitation and temperature) during grain development also occurred, with even highly heritable components differing in amount between grain samples grown in different years on different sites.

Effects of Genotype and Environment on the Content and Composition of Phytochemicals and Dietary Fiber Components in Rye in the HEALTHGRAIN Diversity Screen

The effects of genotype and environment on the content of bioactive components in rye were determined with four varieties being grown on one site for three years and on three additional sites in the third year and a fourth variety being included in all trials except year 1. Clear differences were observed in the extent to which the contents of dietary fiber components (arabinoxylan, beta-glucan, total dietary fiber) and phytochemicals (folates, alkylresorcinols, sterols, tocols, phenolic acids) varied between varieties and between the same varieties grown in different sites (United Kingdom, France, Hungary, Poland) and years (2005-2007 in Hungary), with sterols being the most stable and phenolic acids the least. However, no single variety could be selected as having the highest overall level of bioactive components or as being more stable in comparison across environments.

Contents of dietary fibre components and their relation to associated bioactive components in whole grain wheat samples from the HEALTHGRAIN diversity screen

A large and diverse material collection of whole grain wheat samples (n=129) was analysed for total dietary fibre (TDF) content and composition, including fructan (11.5-15.5%). Correlations between the dietary fibre components, associated bioactive components (e.g. tocols, sterols, phenolic acids and folates) and agronomic properties previously determined on the same samples were found with multivariate analysis (PCA). Samples from the same countries had similar characteristics. The first PC described variation in components concentrated in the starchy endosperm (e.g. starch, β-glucan and fructan) and the dietary fibre components concentrated in the bran (e.g. TDF, arabinoxylan and cellulose). The second PC described the variation in kernel weight and other bran components such as alkylresorcinols, tocols and sterols. Interestingly, there was no correlation among these different groups of bran components, which reflected their concentration in different bran tissues. The results are of importance for plant breeders who wish to develop varieties with health-promoting effects.

Dihydrovitamin K1 in oils and margarines

Abstract In the present study the vitamin K1 and 2′,3′-dihydrovitamin K1 contents of several crude vegetable oils, partially hydrogenated oils used as raw materials in the margarine industry and margarines were analysed with a high-performance liquid chromatographic (HPLC) method. Prior to quantification by reverse-phase HPLC with an electrochemical (EC) detector, hexane extracts of samples were purified by straight-phase semipreparative HPLC. Menaquinone-4 (MK-4) was used as an internal standard. All hydrogenated oils (rapeseed, soybean and mixture of rapeseed and palm) contained considerable amounts of 2′,3′-dihydrovitamin K1, which accounted for approximately 60% of the sum of 2′,3′-dihydrovitamin K1 and vitamin K1; however, among the margarines analysed 2′,3′-dihydrovitamin K1 was found only in hard margarines meant for the baking industry. The proportion of 2′,3′-dihydrovitamin K1 in these products was 25% of the total. The appearance of 2′,3′-dihydrovitamin K1 among the samples analysed correlated with that of trans fatty acids. During recent years the Finnish margarine industry has focused on reducing the amount of trans fatty acids in soft margarines. It was concluded that because of these changes in the manufacturing process, 2′,3′-dihydrovitamin K1 plays no significant role in vitamin K nutrition in Finland.