Dorota Majchrzak

B-vitamin status and concentrations of homocysteine in Austrian omnivores, vegetarians and vegans.

Background: A vegetarian diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases and cancer. However, a vegetarian diet may be deficient in some nutrients. Exclusion of animal products in vegetarian diets may affect the status of certain B-vitamins, and further cause the rise of plasma homocysteine concentration. Objective: The nutritional status of various B-vitamins (B1, B2, B6, B12, folic acid) and the concentration of homocysteine in blood plasma of omnivores (n = 40), vegetarians (n = 36) and vegans (n = 42) in Austria was evaluated. Methods: The evaluation was done using the functional parameters erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamic oxaloacetic transaminase (EGOT) activation coefficients. Enzyme activity was measured photometrically. The quantity of vitamins B1, B2 and B6 in urine and the concentrations of vitamin B6 and homocysteine in plasma were determined by HPLC methods with fluorescence detection. Plasma concentration of vitamin B12 and folic acid were measured with radioimmunoassay. Results: Most of the subjects showed a satisfying vitamin B1 status. Vegans presented a significantly lower mean plasma vitamin B12 concentration than omnivores and vegetarians and deficiency in 2.4% of the volunteers but the highest mean value of plasma folate among the investigated groups. A deficient status of folate was found in 18% of omnivores and in approximately 10% of vegans and vegetarians. The status of riboflavin is considered to be deficient in about 10% of omnivores and vegetarians and in over 30% of vegans. According to the activation coefficient of GOT, approximately one third of all subjects showed vitamin B6 deficiency. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and about 45–50% of the omnivores and vegetarians. Vegan subjects had significantly higher mean plasma homocysteine levels than omnivores. Conclusion: Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B12 and B2 may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma. Pyridoxine status appeared to be independent of the diet.

The Thiamine Status of Adult Humans Depends on Carbohydrate Intake

Thiamine requirements for humans are generally expressed as absolute values per day (mg/d) or in relation to total caloric intake. Limited data are available on the relation between thiamine requirements and the intake of carbohydrates. This study was performed to investigate the influence of stepwise increases of carbohydrate intake on the status of thiamine in healthy volunteers under isocaloric conditions. During an adaptation phase of four days, the carbohydrate intake of twelve healthy volunteers (6 male, 6 female) was 55% of total energy intake. During the subsequent intervention periods, carbohydrate intake was increased to 65% of total energy for four days and to 75% for another four days. Thiamine intake, total energy intake, and physical activity were kept constant throughout the study. HPLC analysis was used to measure thiamine in plasma, urine and feces. Erythrocyte transketolase activity (ETK) was determined enzymatically. During the intervention periods thiamine decreased significantly (p < 0.05) in plasma (from 19.3 +/- 3.3 to 16.4 +/- 4.0 nmol/l) as well as in urine (from 72 +/- 56 to 58 +/- 21 mumol/mol creatinine). ETK and feces content of thiamine remained unchanged. An increase of dietary carbohydrate intake from 55% to 65% and 75%, respectively, of total caloric intake for four days per period at isocaloric conditions causes a decrease of plasma and urine levels of thiamine without affecting enzyme activities.

Influence of probiotic and conventional yoghurt on the status of vitamins B1, B2 and B6 in young healthy women.

Background: In vitro studies indicate that yoghurt bacteria are able to generate several water-soluble vitamins and therefore yoghurt could be a good source of these micronutrients. However, whether lactobacilli or other viable bacteria release the synthesized vitamins or utilize vitamins from their surroundings is a matter of debate. This study was carried out to investigate whether probiotic and traditional yoghurt bacteria are able to influence the status of different B vitamins (B1, B2, B6) in young healthy women. Methods: In this investigation, female volunteers consumed 100 g/day of probiotic (n = 17) or conventional yoghurt (n = 16) for 2 weeks (T1–T2) and 200 g/day for another 2 weeks (T2–T3). A wash-out phase lasting 2 weeks followed. Plasma and urine concentrations of thiamine (vitamin B1), riboflavin (B2) and pyridoxine (B6) were analyzed using HPLC. The functional parameters, i.e. the erythrocyte transketolase (α-ETK) expressed as TPP (thiamine pyrophosphate) effect, erythrocyte glutathione reductase (α-EGR) and glutamic oxaloacetic transaminase (α-EGOT) were determined photometrically. Results: The plasma levels of vitamin B1 increased significantly in both the probiotic (p < 0.001) and the control group (p < 0.01) when consuming 200 g yoghurt/day (T2–T3) and decreased to the baseline levels after the wash-out phase (T3–T4). Urinary excretion of thiamine and the TPP effect did not significantly change in either the probiotic or the control group during the period of daily yoghurt consumption (T1–T3). The plasma concentration of flavin adenine dinucleotide (FAD) decreased significantly (p < 0.001) after consuming 100 g yoghurt/day (T1–T2) while plasma concentrations of flavin mononucleotide (FMN) (probiotic: p < 0.01, control: p < 0.001) and free riboflavin increased significantly (probiotic: p < 0.01, control: p < 0.001). Afterwards, the levels of these parameters remained unchanged to the end of the study in both tested groups. The urinary excretion of riboflavin and α-EGR remained unaffected throughout the study in both the probiotic and the control group. The average status of vitamin B6, evaluated by its plasma level, urinary excretion and α-EGOT was unaffected by daily intake of 100 g (T1–T2) and 200 g yoghurt (T2–T3), respectively, for 4 weeks (T1–T3). Conclusion: The results of the present study indicate that daily consumption of 200 g of both, probiotic and conventional yoghurt for 2 weeks can contribute to the total intake of vitamin B1 and B2 reflected by increased levels of plasma thiamine and free riboflavin in healthy women. The diminished plasma FAD and increased FMN concentrations, observed during the period of daily yoghurt consumption in both groups, may be the result of enhanced immune function and an oxidant/antioxidant imbalance, caused by the daily intake of lactic acid bacteria. Since the long term status parameters of all three investigated vitamins (B1, B2, B6) remained unaffected during the investigation the changes in plasma concentrations seem more likely the result of regular yoghurt consumption as a fermented dairy product, rather than of the specific intake of probiotic bacteria.

Changes in sensory quality characteristics of coffee during storage

How long can roasted coffee beans be stored, without reducing the typical coffee flavor which is mainly responsible for consumers’ enjoyment? In Austria, most coffee packages have a best-before date between 12 and 24 months, but it is not regulated by law. Therefore, there is the need to evaluate changes in sensory qualities of coffee beverages prepared from stored coffee beans. For preparation of the coffee beverages, the paper filter method was used. In the quantitative descriptive analysis (QDA) 10 trained assessors evaluated the intensity of 30 coffee attributes after roasting at the 9th and 18th month of storage, respectively. The sensory evaluation results showed reduction in the sensory qualities of coffee beverages after 9 months storage of roasted coffee beans. The positive associated odor and flavor attributes decreased in their intensity, whereas the negative associated odor and flavor attributes increased significantly (P < 0.05). After 18 months of storage, the rancid odor and flavor which indicate oxidation processes were even considerably perceivable. Consequently, we can assume that changes in sensory quality characteristics of roasted and vacuum-packed coffee beans during storage are possible.

Phylloquinone (vitamin K1) content of commercially-available baby food products

Abstract The contents of phylloquinone (vitamin K1) were investigated in two batches of 62 commercially available baby food products, by HPLC. They comprised vegetable products for babies from 5, 8 and 12 months and fruit and cereal products of three different brands. Vitamin K1 was detected in all analyzed products. In vegetable products for babies from 5 months, the mean content of phylloquinone ranged from 30 to 100 μg/100 g, except for ‘Samples with spinach’, which provided 700 μg vitamin K1/100 g on average. Vegetable products for babies from 8 months and from 12 months showed similar values. In the group of fruit and cereal products, the contents of phylloquinone were lower and varied between 10 and 20 μg/100 g only, except for ‘Various cereals’ (46 μg/100 g). The analyzed baby food products are a very good source of phylloquinone and are therefore excellent as a supplement to breast milk.

Influence of a Probiotic Yoghurt on the Status of Vitamins B1, B2 and B6 in the Healthy Adult Human

Background/Aims: The main reason for this study was to determine whether yoghurt bacteria, being rich in some water-soluble vitamins, release them or utilize vitamins from their surroundings. Our study was trying to determine for the first time, if the viable bacteria of probiotic yoghurt are able to influence the parameters of the B-vitamin (B1, B2, B6) status of the healthy adult human. Methods: The test yoghurt was commercially available probiotic yoghurt prepared with Streptococcus thermophilus and Lactobacillus acidophilus, enriched with Lactobacillus casei GG. Different chemical forms of all investigated B-vitamins were determined by HPLC methods. In order to determine the influence of the yoghurt flora, each of 12 subjects consumed four yoghurt portions 125 g each ( = 500 g) a day, containing thermally inactivated cultures during the first 2-week period and yoghurt without heat treatment during the second 2-week period. Results: The heat treatment of the probiotic yoghurt caused negligible changes in vitamin contents. The plasma levels of thiamin decreased significantly (p < 0.01) after the first 2-week period and kept on decreasing during the second 2-week period. A similar trend was found in the urinary excretion. The plasma levels of the B2-vitamers were different. The flavin adenine dinucleotide concentrations increased significantly (p < 0.01) after the consumption of heat-treated yoghurt and decreased significantly (p < 0.05) after the following 2 weeks, in which the subjects received the untreated yoghurt. In contrast, the flavin mononucleotide plasma levels decreased during the first 2-week period and increased during the second part of the study, but the change was not statistically significant. The free riboflavin concentrations in plasma and urine showed a continuous but not significant increase. The concentrations of pyridoxal-5-phosphate in plasma increased after the consumption of yoghurt with the inactivated bacteria and decreased in the second part of the study. However, the differences were not significant. The excretion of thiamin, B2- and B6-vitamers in the faeces did not significantly change throughout the study period (p > 0.05). Conclusions: Our observations show that the bacterial flora of the examined yoghurt does not influence the vitamin B1, B2 and B6 status of man. It seems likely that even lactobacilli of the ‘probiotic’ type which are vitamin B consumers can decrease the bioavailability of these vitamins for man. Obviously a thermal death of the cells did not induce a release of physiologically active vitamins.

Effects of beta-carotene supplementation on free radical mechanism in healthy adult subjects.

AIM The objective of this study was to examine whether increasing doses of beta-carotene supplements have effects on biological markers of lipid peroxidation in healthy volunteers. SUBJECTS AND METHODS Forty-two healthy subjects were supplemented with 5 mg, 10 mg, 20 mg or 40 mg beta-carotene/day, respectively for five weeks. Plasma beta-carotene and tocopherol levels, malondialdehyde-thiobarbituric reactive substances (MDA-TBARS), and conjugated dienes were determined using high-performance liquid chromatography (HPLC). Concentrations of ascorbic acid, uric acid, and the total antioxidative capacity (TAC) in plasma were measured photometrically. RESULTS Plasma beta-carotene levels increased significantly according to the intervention dose (p < 0.001), and concentrations of tocopherol equivalents and ascorbic acid were within the physiological range except in the 5 mg intervention group where a significant decrease of vitamin C was assessed (p < 0.05). Uric acid in plasma decreased significantly in all groups (p < 0.05) up to the end of investigation, but was within the normal range. Trolox equivalent antioxidative capacity (TEAC) decreased significantly (p < 0.001) in all groups during supplementation. MDA-TBARS remained unchanged after five weeks except for the 40 mg beta-carotene substitution group, where a significant decrease was observed (p < 0.05). CONCLUSION Beta-carotene supplementation of healthy subjects significantly increased plasma beta-carotene status without inducing adverse biological effects. Beta-carotene did not especially protect against oxidative stress, except for the 40 mg group. These data suggest that additional effects of beta-carotene supplementation on well-nourished, healthy subjects are limited.

Selected quality parameters of salmon and meat when fried with or without added fat.

AIM To determine whether pan-frying (pork, beef and salmon) without oil or with different fats (olive oil, corn oil or a partially hydrogenated plant oil) or steaming (only salmon) have effects on the total fat content, the fatty acid pattern, lipid peroxidation, tocopherols and in particular for salmon on vitamin D(3) and astaxanthin. MATERIAL AND METHODS Pork, beef patties and salmon were pan-fried (6 min each), beef fillet was pan-fried (5 min) with an additional braising period of 90 minutes and salmon was steamed for 12 minutes. Each pan-frying treatment was done with the above mentioned fats and without fat. Total fat was determined gravimetrically, the fatty acid pattern with GC, the tocopherols, astaxanthin and vitamin D(3) by using HPLC. RESULTS The effects on the fat quality and quantity in the final products were related to the pan-frying fat used, however, the power of the outcome was depending on the surface to volume ratio. The highest increase in total fat was observed for pork, followed by the beef patties and the braised beef. The same has been assessed for the fatty acid pattern. Tocopherols changed according to the oil used, in particular gamma-tocopherol significantly increased for each preparation after the use of corn oil. Only in pork an increase in lipid oxidation of the oil preparations has been observed. Vitamin D(3) in salmon significantly decreased after heat treatment, however a 150 g salmon portion would provide between 13.9 and 14.7 mug Vitamin D(3) which is around five times more than the average daily intake. CONCLUSION Pan-frying without fat can be recommended for the daily use, since the total fat intake is too high in developed countries and one main task of nutritional recommendations is to reduce the total fat intake. When pan-fried with fat, the choice of the fat is of high importance since it directly influences the quality and the flavour of the final product. In order to increase the fat quality from nutritional point of view only oils of plant or vegetable origin should be used in households. Pan-fried salmon is a good source of Vitamin D(3).

Fatty acid profile in baby food products

Dietary lipids are the major energy source for infants andyoung children. Lipid tissue accretion in growing infants isvery high and contributes 90% of all energy deposited inthe body during the first six months of life [1, 2]. The mostimportant functional components of dietary lipids (triglyc-erides, phospholipids and cholesterol esters), particularlylong-chain polyunsaturated fatty acids (LC-PUFA) arefundamental to normal growth and the development of in-fants [3, 4]. The two families of LC-PUFAs, the n-3 andthe n-6 have specific functions: docosahexaenoic acid(DHA; C22:6n3) in retina and brain, whereas arachidonicacid (AA; C20:4n6) is the precursor of prostaglandins andleucotrienes and is also a major brain component. AAandDHA are deposited in large amounts in the nonmyelinmembranes of the developing central nervous system. In-adequate supplies of n-6 and n-3 fatty acids during ner-vous system development are of concern because of pos-sible long-term changes in learning ability and reduced vi-sual function [5]. Current evidence suggests that the new-born is able to synthesize AA and DHA from linoleic acid(LA, C18:2n6) and α-linolenic acid (ALA, C18:3n3), re-spectively [6]. However, the amount of LC-PUFA beingproduced, particularly of DHA, may not be sufficient tomeet the developmental requirement of the infant [7, 8].The newborn term infant has a limited desaturating ca-pacity and depends on an exogenous supply of LC-PUFAs during the first months of life [9]. A dietary lack ofessential fatty acids and their derivatives is evident also inweaned children during the second half of their first yearof life [10]. Human milk is the best source of fat and di-etary essential fatty acids for infant feeding; it provides acomplex mixture of fatty acids, including the essential 18-carbon polyunsaturated (LA, ALA) and many long-chain(20- and 22-carbon) polyunsaturated fatty acids (AA,DHA) [7, 11, 12], whereas commercially available infantformulas usually prepared with plant oils containing only18-carbon essential fatty acids [12]. DHA and AA arefound in many non-vegetable foods (fish, meat, eggs).For this reason an intake of baby food products, particu-larly prepared with meat, could be of great importance ascomplementary feeding to formula milk. Commerciallyavailable infant foods reported by

Do Visually Impaired People Develop Superior Smell Ability

It is well known that visually impaired people perform better in orientation by sound than sighted individuals, but it is not clear whether this enhanced awareness also extends to other senses. Therefore, the aim of this study was to observe whether visually impaired subjects develop superior abilities in olfactory perception to compensate for their lack of vision. We investigated the odor perception of visually impaired individuals aged 7 to 89 (n = 99; 52 women, 47 men) and compared them with subjects of a control group aged 8 to 82 years (n = 100; 45 women, 55 men) without any visual impairment. The participants were evaluated by Sniffin’ Sticks odor identification and discrimination test. Identification ability was assessed for 16 common odors presented in felt-tip pens. In the odor discrimination task, subjects had to determine which of three pens in 16 triplets had a different odor. The median number of correctly identified odorant pens in both groups was the same, 13 of the offered 16. In the discrimination test, there was also no significant difference observed. Gender did not influence results. Age-related changes were observed in both groups with olfactory perception decreasing after the age of 51. We could not confirm that visually impaired people were better in smell identification and discrimination ability than sighted individuals.