Tocopherol and tocotrienol content of hazelnut cultivars grown in portugal

Nutrient Composition of Different Hazelnut Cultivars Grown in Germany

Hazelnuts are rarely cultivated in Germany, although they are a valuable source for macro- and micronutrients and can thus contribute to a healthy diet. Near the present, 15 varieties were cultivated in Thuringia, Germany, as a pilot study for further research. The aim of our study was to evaluate the micro- and macronutrient composition of representative, randomly mixed samples of the 15 different hazelnut cultivars. Protein, fat, and fiber contents were determined using established methods. Fatty acids, tocopherols, minerals, trace elements, and ultra-trace elements were analyzed using gas chromatography, high-performance liquid chromatography, and inductively coupled plasma triple quadrupole mass-spectrometry, respectively. We found that the different hazelnut varieties contained valuable amounts of fat, protein, dietary fiber, minerals, trace elements, and α-tocopherol, however, in different quantities. The variations in nutrient composition were independent of growth conditions, which were identical for all hazelnut varieties. Therefore, each hazelnut cultivar has its specific nutrient profile.

Food Targeting: Geographical Origin Determination of Hazelnuts (Corylus avellana) by LC-QqQ-MS/MS-Based Targeted Metabolomics Application

A targeted metabolomics LC-ESI-QqQ-MS application for geographical origin discrimination based on 20 nonpolar key metabolites was developed, validated according to accepted guidelines and used for quantitation via stable isotope labeled internal standards in 202 raw authentic hazelnut samples from six countries (Turkey, Italy, Georgia, Spain, France, and Germany) of harvest years 2014 and 2015. Multivariate statistics were used for detection of significant variations in metabolite levels between countries and, moreover, a prediction model using support vector machine classification (SVM) was calculated yielding 100% training accuracy and 97% cross-validation accuracy, which was subsequently applied to 55 hazelnut samples for the confectionary industry gaining up to 80% correct classifications compared to declared origin. The present method demonstrates the great suitability for targeted metabolomics applications in the geographical origin determination of hazelnuts and their applicability in routine analytics.

Metabolic Profiling in Chinese Cabbage (Brassica rapa L. subsp. pekinensis) Cultivars Reveals that Glucosinolate Content Is Correlated with Carotenoid Content

A total of 38 bioactive compounds, including glucosinolates, carotenoids, tocopherols, sterols, and policosanols, were characterized from nine varieties of Chinese cabbage (Brassica rapa L. subsp. pekinensis) to determine their phytochemical diversity and analyze their abundance relationships. The metabolite profiles were evaluated with principal component analysis (PCA), Pearson correlation analysis, and hierarchical clustering analysis (HCA). PCA and HCA identified two distinct varieties of Chinese cabbage (Cheonsangcheonha and Waldongcheonha) with higher levels of glucosinolates and carotenoids. Pairwise comparisons of the 38 metabolites were calculated using Pearson correlation coefficients. The HCA, which used the correlation coefficients, clustered metabolites that are derived from closely related biochemical pathways. Significant correlations were discovered between chlorophyll and carotenoids. Additionally, aliphatic glucosinolate and carotenoid levels were positively correlated. The Cheonsangcheonha and Waldongcheonha varieties appear to be good candidates for breeding because they have high glucosinolate and carotenoid levels.

Potential of tocotrienols in the prevention and therapy of Alzheimer's disease

Currently there is no cure for Alzheimer's disease (AD); clinical trials are underway to reduce amyloid generation and deposition, a neuropathological hallmark in brains of AD patients. While genetic factors and neuroinflammation contribute significantly to AD pathogenesis, whether increased cholesterol level is a causative factor or a result of AD is equivocal. Prenylation of proteins regulating neuronal functions requires mevalonate-derived farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). The observation that the levels of FPP and GGPP, but not that of cholesterol, are elevated in AD patients is consistent with the finding that statins, competitive inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, reduce FPP and GGPP levels and amyloid β protein production in preclinical studies. Retrospective studies show inverse correlations between incidence of AD and the intake and serum levels of the HMG CoA reductase-suppressive tocotrienols; tocopherols show mixed results. Tocotrienols, but not tocopherols, block the processing and nuclear localization of sterol regulatory element binding protein-2, the transcriptional factor for HMG CoA reductase and FPP synthase, and enhance the degradation of HMG CoA reductase. Consequently, tocotrienols deplete the pool of FPP and GGPP and potentially blunt prenylation-dependent AD pathogenesis. The antiinflammatory activity of tocotrienols further contributes to their protection against AD. The mevalonate- and inflammation-suppressive activities of tocotrienols may represent those of an estimated 23,000 mevalonate-derived plant secondary metabolites called isoprenoids, many of which are neuroprotective. Tocotrienol-containing plant foods and tocotrienol derivatives and formulations with enhanced bioavailability may offer a novel approach in AD prevention and treatment.

Nut traits and nutritional composition of hazelnut (Corylus avellana L.) as influenced by zinc fertilization

BACKGROUND

Zinc is an essential element for plants and its deficiency is a widespread problem throughout the world, causing decreased yields and nutritional quality. In this study the effect of zinc fertilization on some nut traits and the nutritional composition of 'Tombul' hazelnut (Corylus avellana L.) variety cultivated in the Black Sea region of Turkey was investigated and the contribution of this nut to human nutrition determined. Trials were carried out at 'Tombul' hazelnut orchards, and zinc fertilizers were applied at 0, 0.2, 0.4, 0.8 and 1.6 kg Zn ha(-1) in three consecutive years.

RESULTS

Significant differences in some nut traits and mineral composition (protein, total oil, ash, kernel percentage, empty and wrinkled nuts, copper, boron, manganese and molybdenum) were observed with zinc fertilizer applications. In terms of daily nutritional element requirements, 100 g of hazelnut provided about 44.74% phosphorus, 13.39% potassium, 19.32% calcium, 37.49% magnesium, 0.19% sodium, 51.63% iron, 25.73% zinc and 14.05% boron of the recommended daily amounts (RDAs), while copper, manganese and molybdenum contents exceeded their RDAs.

CONCLUSION

In order to improve some nut traits and the mineral composition of hazelnut, 0.8 and 1.6 kg Zn ha(-1) fertilizations could be recommended in practice.

Nutritional evaluation and health promoting activities of nuts and seeds cultivated in Greece

Available data suggest that genetic as well as environmental factors may influence nuts and seeds nutrients content. In this context nuts and seeds cultivated in Greece were studied. Macronutrients content was in agreement with that from other areas. Total phenolics content was in the range of 43.0 ± 2.1-1512.7 ± 60.7 mg GAE/100 g for chestnut and walnut, respectively. Thirteen to 22 individual phenolics were identified in the studied species. Oleanolic acid was in the range of 0.10-9.03 mg/100 g. Pumpkin seeds contained the higher squalene content (71.6 mg/100 g). β-Sitosterol predominated in all samples except pumpkin seeds. Tocopherols ranged from 8.9 mg/100 g (chestnut) to 29.3 mg/100 g (almond). Nuts and seeds hydrophilic extracts at quantities corresponding to the estimated daily consumption by the Greeks succeeded in inhibiting LDL oxidation in vitro by increasing lag time 1.1-14.1 times. One serving of nuts or seeds may cover a significant fraction of health promoting microconstituents daily intake.

Tocotrienols, the vitamin E of the 21st century: its potential against cancer and other chronic diseases

Initially discovered in 1938 as a "fertility factor," vitamin E now refers to eight different isoforms that belong to two categories, four saturated analogues (α, β, γ, and δ) called tocopherols and four unsaturated analogues referred to as tocotrienols. While the tocopherols have been investigated extensively, little is known about the tocotrienols. Very limited studies suggest that both the molecular and therapeutic targets of the tocotrienols are distinct from those of the tocopherols. For instance, suppression of inflammatory transcription factor NF-κB, which is closely linked to tumorigenesis and inhibition of HMG-CoA reductase, mammalian DNA polymerases and certain protein tyrosine kinases, is unique to the tocotrienols. This review examines in detail the molecular targets of the tocotrienols and their roles in cancer, bone resorption, diabetes, and cardiovascular and neurological diseases at both preclinical and clinical levels. As disappointment with the therapeutic value of the tocopherols grows, the potential of these novel vitamin E analogues awaits further investigation.

Vitamin E content of foods: Comparison of results obtained from food composition tables and HPLC analysis

BACKGROUND & AIMS

Data on vitamin E content of foods are essential for nutrition research and its application. The aim of this study was to investigate the precision of calculated vitamin E content of prepared meals.

METHODS

The vitamin E content of 69 dishes of a menu cycle sampled at two occasions were calculated using 4 different food composition tables (FCT) and measured by HPLC.

RESULTS

Data were complete for 50-69 dishes. The proportion of dishes with differences between FCTs < or = 20% were 17-100%. Differences between HPLC and the Souci-Fachmann-Kraut table were < or = 20% in 8/46 dishes for alpha- and in 14/46 dishes for gamma-tocopherol. Differences fell in the order of baked > raw > fried/roasted > boiled > mixed prepared foods. The 2 samplings taken 6 months apart showed considerable differences.

CONCLUSIONS

There are substantial differences in calculated/measured vitamin E content of prepared foods: (i) between different FCTs; (ii) between FCTs and HPLC, and (iii) between different seasons. This can be explained by intrinsic variability (breeding, season, country of origin, ripeness, freshness) and food processing, as well as selection of FCTs and should be taken into account when interpreting data of dietary intervention studies.