"Unhealthy = Tasty": How Does It Affect Consumers' (Un)Healthy Food Expectations?

Consumers having a strong unhealthy = tasty (UT) belief are less likely to choose healthy food even though they recognize its health benefits, because they assume healthy food to be unpalatable. The aim of this study was to profile consumers according to their UT belief and specify the strength of the belief among a demographically representative consumer group. The other aim was to investigate the effect of UT belief on expectations of two food products representing either an unhealthy or a healthy image. A total of 1537 consumers participated in the online survey. The scale-based (1-7) mean for UT belief was 3.27 and related positively to male gender and food pleasure orientation and negatively to general health interest. The results indicate that a strong UT belief correlates with positive expectations of unhealthy food and with negative expectations of healthy food. UT belief seemed to increase expected food-associated guilt, but other strong food-related attitudes (health interest with unhealthy food and pleasure orientation with healthy food) reduced this effect. In practice, understanding the relationship between UT belief and personal factors and attitudes, and the importance of this belief to food expectations can assist in finding the tools to encourage consumers towards healthier food choices.

Effects of Weak Acids on the Microbiological, Nutritional and Sensory Quality of Baltic Herring (Clupea harengus membras)

Baltic herring (Clupea harengus membras) pickled in vinegar is a common product in the Nordic countries. Other weak acids are used to cook and preserve fish in other food cultures. The aim of this study was to evaluate the potential of weak acids to produce safe and nutritious pickled fish products with varying sensory properties. The influence of acetic, citric, lactic, malic, and tartaric acids on the preservability and quality of pickled and marinated Baltic herring was studied by measuring microbiological quality, pH, chemical composition, and lipid oxidation and by sensory profiling. Pickling with these acids with pH levels of 3.7-4.2 resulted in pickled Baltic herring products with high microbiological quality. The results of the chemical analysis of the samples indicated that pickling and storage on marinade influenced the chemical composition of fish. The most significant changes in chemical composition were the increase in moisture and decrease in protein content of the samples during storage. Fat content decreased during the storage period in acetic acid and malic acid samples. All tested acids inhibited lipid oxidation for one month, but at three and four month time points, the content of oxidation products increased except in the samples pickled with tartaric acid. The highest oxidation level was observed in the case of citric acid and the lowest with tartaric acid. The results indicate that replacing acetic acid with other weak acids frequently used in the food industry results in pickled and marinated fish products with novel and milder sensory profiles.

The sound of silence: Presence and absence of sound affects meal duration and hedonic eating experience

The interplay between external auditory cues in the eating environment and cognitive processes, such as distraction, may influence food intake, but how and the degree to which they do is unclear. We report an experiment designed to investigate the effects of different sonic atmospheres on meal duration, food intake and evaluations, and responses to the sonic eating environment. In a quasi-naturalistic cafeteria setting, participants (N = 248) were eating a lunch meal whilst being in one of four conditions: slow music, fast music, cafeteria noise, and silence. The results revealed that participants eating their lunch while exposed to some kind of background sound spent more time on their meal than those eating in silence. In terms of music tempo, slow music prolonged meal duration compared to fast music, but did not lead to increased intake. The appropriateness and liking of the sonic atmosphere were positively correlated with the overall pleasantness of the eating experience and liking of the food. The findings provide support for existing evidence documenting the importance of ambient sound in relation to food experiences and provide further insights into how individuals perceive and respond to sonic meal environments. Results are discussed in terms of recommendations for future design of eating environments in different contexts.

APOE genotypes, lipid profiles and associated clinical markers in a Finnish population with cardiovascular disease risk factors

INTRODUCTION

APOE ɛ4 allele predisposes to high cholesterol and increases the risk for lifestyle-related diseases such as Alzheimer's disease (AD) and cardiovascular diseases (CVD). The aim of this study was to analyse interrelationships of APOE genotypes with lipid metabolism and lifestyle factors in middle-aged Finns among whom the CVD risk factors are common.

METHODS

Participants (n=211) were analysed for APOE ε genotypes, physiological parameters and health- and diet-related plasma markers. Lifestyle choices were determined by a questionnaire.

RESULTS

APOE genotypes ε3/ε4 and ε4/ε4 (ε4 group) represented 34.1% of the participants. Genotype ε3/ε3 (ε3 group) frequency was 54.5%. Carriers of ε2 (ε2 group; ε2/ε2, ε2/ε3 and ε2/ε4) represented 11.4%; 1.9 % were of the genotype ε2/ε4. The LDL and total cholesterol levels were lower (P<0.05) in the ε2 carriers than in the ε3 or ε4 groups, while the ε3 and ε4 groups did not differ. Proportions of plasma saturated fatty acids were higher (P<0.01) and omega-6 fatty acids lower (P=0.01) in the ε2 carriers compared with the ε4 group. The ε2 carriers had a higher (P<0.05) percentage of 22:4n-6 and 22:5n-6 and a lower (P<0.05) percentage of 24:5n-3 and 24:6n-3 than individuals without the ε2 allele.

CONCLUSIONS

The plasma fatty acid profiles in the ε2 group were characterised by higher SFA and lower omega-6 fatty acid proportions. Their lower cholesterol values indicated a lower risk for CVD compared with the ε4 group. A novel finding was that the ε2 carriers had different proportions of 22:4n-6, 22:5n-6, 24:5n-3 and 24:6n-3 than individuals without the ε2 allele. The significance of the differences in fatty acid composition remains to be studied.

Comparing the taste-modifying properties of nanocellulose and carboxymethyl cellulose

The taste-modifying properties of nanofibrillar cellulose (NFC) and carboxymethyl cellulose (CMC) are compared for the first time. The samples were prepared in the form of gels, with and without added sweet and bitter taste components. As viscosity itself is known to affect taste perception, the viscosities of NFC and CMC samples were set to the same level as shear rates commonly found in the oral cavity. A trained panel of 10 assessors evaluated the bitterness and sweetness of the samples. Further, the assessors were given an opportunity to describe the samples in free words. The taste-modifying capacities of the thickening agents were at the same level when sweet compounds were added. However, CMC was better able to reduce the bitterness of quinine hydrochloride than NFC, which did not show any bitterness-reduction ability with the compound. This was unexpected, as our previous studies of NFC showed fairly high binding capacity with quinine. The open-ended responses revealed that the NFC-containing samples had an astringent sensation, while certain assessors observed a sensation of saltiness in the CMC samples. This may explain the inability of NFC to mask the bitterness of quinine hydrochloride, as astringency may act as a bitterness enhancer, while saltiness may suppress it. Both thickening agents were perceived as slightly bitter. Our study reveals the need for further assessment of the orosensory properties of NFC, particularly the magnitude and origin of its astringency, before it can be fully utilized in food industry applications.

Ethical Aspects of Genotype Disclosure: Perceptions of Participants in a Nutrigenetic Study in Finland

OBJECTIVE

The aim of this study was to gain insight into the understanding of genetics and perceptions on the ethical issues related to genotype disclosure of the participants in a nutrigenetic study.

METHODS

A close-ended questionnaire was developed based on literature and discussions among the research group members. The questionnaire contained a -total of 33 questions, which were divided into 4 categories - demographics, knowledge assessment, concerns related to participation, and opinions on disclosure of information. Majority of the participants (250 out of 281) of a nutrigenetic study, in which effect of disclosing APOE allele status on lifestyle changes was studied, completed the questionnaire online following the informed consent process. The responses from the knowledge assessment and the concern categories were transformed into knowledge and concern scales, respectively, and analysed by descriptive statistical methods. The statistical associations between the categorical variables were determined using χ2 test of independence. The relationship between the continuous variables was assessed using Pearson product-moment correlation coefficient and internal consistency of questions by Cronbach's alpha.

RESULTS

No correlation was observed between the level of education and knowledge scores. About 10% of the participants thought that the genetic predisposition would be stressful to them and their family members.

CONCLUSIONS

Careful distribution of information before a nutrigenetic study supports understanding and reduces concerns of genetic susceptibility. In Finland, strong basic education is likely to have strengthened the trust in research process.

APOE Genotype Disclosure and Lifestyle Advice in a Randomized Intervention Study with Finnish Participants

BACKGROUND

The APOE ε4 allele is associated with higher risks of cardiovascular diseases and Alzheimer disease than ε3 and ε2.

OBJECTIVES

We studied the effectiveness of dietary and lifestyle guidance and personal genetic risk information [ε4 carrier (ε4+); ε4 noncarrier (ε4-)] as motivators for a healthier lifestyle.

METHODS

A total of 188 healthy Finnish volunteers (82.4% women; mean ± SD age: 51.0 ± 5.6 y; BMI: 26.0 ± 3.6 kg/m2; total cholesterol: 5.2 ± 0.9 mmol/L) participated in our randomized intervention study. The participants were genotyped for APOE and divided into intervention (INT; INTε4+, n = 33; INTε4-, n = 57) and control groups (CTRL; CTRLε4+, n = 36; CTRLε4-, n = 62). Blood samples, measured observations, and questionnaire data were obtained at baseline and at 1 and 1.5 y. INT participants received their ε4 carrier status at baseline. Monthly Internet-based guidance based on the Finnish Dietary guidelines was provided for all.

RESULTS

The proportion of SFAs in plasma over time fluctuated less in INTε4+ than in the other groups (P-interaction < 0.05; primary outcome). The lifestyle guidance increased vegetable consumption from 3.5 to 3.6 portions/d, improved the dietary fat quality score by 5.3%, increased the plasma n-3 (ω-3) FA proportion by 7.3%, and decreased the consumption of high-fat/high-sugar foods from 7.3 to 6.5 portions/wk and total- and LDL-cholesterol concentrations by 4.3% and 6.1%, respectively, in the entire participant population (P < 0.05; secondary outcome). Compared with the ε4- participants, ε4+ participants had 2.4% higher plasma n-6 (ω-6) FA, lower C-peptide (3.9 compared with 4.2 nmol/L × h) and sensitive C-reactive protein values, and decreased plasma malondialdehyde concentrations over time (P < 0.05; secondary outcome).

CONCLUSIONS

Lifestyle guidance given to healthy Finnish participants yielded small but beneficial changes. The INTε4+ group did not seem markedly more responsive to the guidance than the other groups.This trial was registered at clinicaltrials.gov as NCT03794141.

Information Provided to Consumers about Direct-to-Consumer Nutrigenetic Testing

BACKGROUND

Nutrigenetic tests are often considered to be less serious compared to other health-related genetic tests, although they share similar ethical concerns. Nutrigenetic tests are mainly available through direct-to-consumer genetic testing (DTC GT) and increasing in popularity.

OBJECTIVE

To analyze the contents of nutrigenetic DTC GT websites with respect to the adequacy of the information provided to support a well-informed decision of purchasing the tests.

METHODS

The websites of DTC GT companies selling nutrigenetic tests that could be ordered online without involving any healthcare professional, available in English, marketing tests in Europe, the USA, Australia, or Canada, and accessible from Finland were included in the study (n = 38). Quantitative and qualitative content analyses of the websites were carried out with the help of a codebook.

RESULTS

Of the 38 websites, 8 included a clearly identifiable and easy-to-find information section about genetics. The quality and contents of these sections were often insufficient and/or misleading. Fourteen websites had specific sections discussing the risks related to GT, and on 13 signed informed consent was requested for GT. Furthermore, only 2 of the companies offered any kind of pretest consultation and 13 offered mostly separately charged posttest consultation. The complex structure of the websites made it difficult to find all key information, with many important aspects buried in legal documents, which were challenging to comprehend even for a professional.

CONCLUSION

The structure of the websites and the amount and quality of the content therein do not support a well-informed decision.

A Long-Term Follow-Up Study on Disclosing Genetic Risk Information (APOE) to Promote Healthy Lifestyles in Finland

AIM

This observational follow-up study was designed to assess the long-term behavioural and clinical effects of receiving personal genetic risk information. The information disclosed was the carrier status of the apolipoprotein E (APOE)alleles, which differentially contribute to the genetic risk for cardiovascular disease (CVD) and Alzheimer's disease.

METHODS

This study forms a continuum with a previous 1-year intervention (2010-2011) monitoring the effects of disclosing the carrier status of the APOE ε4risk allele. The follow-up measurements, performed 5.5 years post-intervention, included clinical measurements (blood values and anthropomorphic parameters) and questionnaires (psychological and behavioural factors). The participants were healthy adult volunteers, aged 26-73 years (n = 70) who had participated in the previous intervention, and received their APOE allele status either at the beginning (former test group) or the end of the intervention (former control group).

RESULTS

Personal genetic risk information resulted in a moderate health-conscious change in diet and had a slight positive long-term effect on clinical factors, particularly the serum lipids. These improvements were subsequent to the disclosure of genetic information and occurred mainly in the APOE ε4-positive members of the former control group, that is, those who were at increased genetic risk for CVD but had not been informed of their status before the end of the intervention. In contrast, changes in the values and health behaviour of the APOE ε4-positive individuals in the former test group, who had already changed their health behaviour during the previous intervention as a result of being informed of their carrier status, varied more: some continued to improve, some remained at their previously improved level, and some relapsed slightly. Both groups had nonetheless displayed an improvement immediately subsequent to the disclosure of their personal genetic risk.

CONCLUSION

Receiving information on increased personal genetic risk (carrier status of APOE ε4)for CVD provided the motivation for improvements in health behaviour. The resulting changes, while modest, in most cases remained visible even after a number of years.

The effect of cooking on umami compounds in wild and cultivated mushrooms

The effect of cooking on the taste compounds of five mushroom species Agaricus bisporus, Lactarius trivialis, Cantharellus cibarius, Cantharellus tubaeformis and Suillus variegatus were assessed with a special focus on the compounds responsible for the umami taste. Liquid chromatography was used to analyse free amino acids (FAAs) and 5'-nucleotides from fresh and sous vide (SV) cooked mushroom samples and cooking juice. The SV technique enabled analysis of entire mushrooms, including the liquid released during cooking. FAA content decreased when cooking temperature increased, indicating their further chemical reactions. S. variegatus contained highest concentrations of FAAs in analysed wild mushrooms. The umami-enhancing nucleotide 5'-GMP was detected only in cooked samples, concentration being likely dependent on enzymatic activity. The highest concentration of 5'-GMP was detected in cooked L. trivialis samples (17 mg/100 g fw). To our knowledge, the analysed taste compounds of L. trivialis and S. variegatus are documented for the first time.

Sensory properties of Nordic edible mushrooms

Edible mushrooms are a global food with a history of consumption spanning several millennia. However, studies utilizing modern sensory methods on mushrooms are still scarce. In this study, the sensory properties of Nordic edible mushrooms were analyzed by two methods. In the sensory profile, sous vide processed wild mushroom species Cantharellus cibarius, Craterellus tubaeformis, Boletus edulis, and Lactarius camphoratus were studied with cultivated Agaricus bisporus as a control species. The sensory profile consisted of 18 descriptors, and the 5 mushrooms differed from each other in all of them. Only B. edulis and A. bisporus were linked to typical mushroom-like odor. In projective mapping, consumers evaluated blanched wild C. cibarius, C. tubaeformis and Suillus variegatus as well as cultivated Lentinula edodes and both blanched and fresh A. bisporus based on odor and on flavor. The consumers intuitively grouped the samples into three groups: wild, fresh cultivated and processed cultivated mushrooms. Wild mushrooms had a high odor intensity and various odor descriptions but a low flavor intensity. Cultivated mushrooms had opposite descriptions. Both tests showed differences in the sensory descriptors between the cultivated and wild mushrooms with the former linked to typical 'mushroom', indicating the importance and need for descriptive profiles for different mushroom types.

The effect of gender, age and product type on the origin induced food product experience among young consumers in Finland

Locally produced and sourced food products are gaining popularity among consumers. The effect of the expectations induced by the origin of the food was studied with 1491 consumers in two separate studies among different age groups. In order to test the consumer response to the product origin neutral, domestic, and local conditions were used. Consumers evaluated the product's pleasantness, their probability to choose it, the overall quality, and their willingness to pay. To gather information on whether the phenomenon was consistent, independent from the product category, three different types of products were tested (meat, bread, and vegetables). Our results show that a closer origin does not necessarily produce a positive response, but that there are several moderating factors such as gender, age, and product type. Female university students responded equally to domestic and local origins in the case of bread, but for meat products, only those of local origin induced a positive reaction. In this study population, the male respondents only reacted to a local origin in the case of bread, while domestic meat products provided similar results to local origins. Among young men consumers in the 7th-9th grades responded to the local origin of vegetables positively, while others among the youngest consumers, the origin did not induce a significant effect. The results indicate that even when the product is not appealing itself, locality can still increase the perceived quality.

Free amino acids and 5'-nucleotides in Finnish forest mushrooms

Edible mushrooms are valued because of their umami taste and good nutritional values. Free amino acids, 5'-nucleotides and nucleosides were analyzed from four Nordic forest mushroom species (Lactarius camphoratus, Boletus edulis, Cantharellus cibarius, Craterellus tubaeformis) using high precision liquid chromatography analysis. To our knowledge, these taste components were studied for the first time from Craterellus tubaeformis and Lactarius camphoratus. The focus was on the umami amino acids and 5'-nucleotides. The free amino acid and 5'-nucleotide/nucleoside contents of studied species differed from each other. In all studied samples, umami amino acids were among five major free amino acids. The highest concentration of umami amino acids was on L. camphoratus whereas B. edulis had the highest content of sweet amino acids and C. cibarius had the highest content of bitter amino acids. The content of umami enhancing 5'-nucleotides were low in all studied species.

Effect of Salt Reduction on Consumer Acceptance and Sensory Quality of Food

Reducing salt (NaCl) intake is an important public health target. The food industry and catering services are searching for means to reduce the salt content in their products. This review focuses on options for salt reduction in foods and the sensory evaluation of salt-reduced foods. Simple salt reduction, mineral salts and flavor enhancers/modifiers (e.g., umami compounds) are common options for salt reduction. In addition, the modification of food texture and odor-taste interactions may contribute to enhanced salty taste perception. Maintaining consumer acceptance of the products is a challenge, and recent examples of the consumer perception of salt-reduced foods are presented.

In situ quantitative 1H nuclear magnetic resonance spectroscopy discriminates between raw and steam cooked potato strips based on their metabolites

A direct quantitative proton nuclear magnetic resonance spectroscopy method was developed for the measurement of saccharides, organic acids and amino acids in potato (Solanum tuberosum L.) tuber filaments, a complex gel-like food matrix. The method requires minimal sample preparation. It is thus a faster alternative compared to liquid sample matrices, as well as an extension to methods analyzing only selected metabolites in the sample. The samples in this study were either raw or steamed potato strips that were either measured as D₂O extracts or directly without extraction or derivatization steps (in situ technique). A total of 22 compounds were identified in extracts and 18 in potato strips. Of these, 20 compounds were quantifiable in potato extracts and 13 compounds in potato strips. The effect of thermal processing was reflected in the profile of analyzed compounds. One example was fumaric acid, which was completely lost in steamed samples in both measurement techniques. Additionally, the content of γ-aminobutyric acid in steamed potato strips was lower. In potato extracts, the contents of additional 7 compounds were statistically different. The raw and steamed samples separated into two groups with multivariate models both in extracts and potato strips, and these groups were linked to changes in aforementioned compounds. These results demonstrated that the in situ quantitative ¹H NMR technique is a useful tool to analyze potato metabolites. This technique could be further applied to any gel-like complex matrix, meaning that lengthy sample pretreatment could be skipped.

Using ApoE Genotyping to Promote Healthy Lifestyles in Finland - Psychological Impacts: Randomized Controlled Trial

Common health recommendations often incite very little public response, as people instead require individualized information. The purpose of this study was to assess the psychological effects of personal genetic information, provided by different apoE genotypes, as a tool to promote lifestyle changes. This study was a one-year intervention study using healthy adults, aged 20-67 years (n = 107). Their experiences of state anxiety, threat and stage of change were measured three times over a 12 months period. These psychological experiences were assessed, during the genetic information gathering, for three groups: a high-risk group (Ɛ4+, n = 16); a low-risk group (Ɛ4-, n = 35); and a control group (n = 56). The psychological effects of personal genetic risk information were shown to be short-term, although the levels of state anxiety and threat experiences in the high-risk group both remained at a slightly higher level than in the baseline. Threat experiences differed almost significantly (alpha = 0.017) between the Ɛ4+ and Ɛ4- groups (p = 0.034). Information on the apoE genotype impacted the experience of cardiovascular threat; this effect was most intense immediately after genetic feedback was received. However, fears of threat and anxiety may not be an obstacle for using gene information to motivate healthy, stable adults towards making lifestyle changes. Further studies should thus focus on how to utilize genetic screening in prevention of lifestyle-related diseases.

An intervention study of individual, apoE genotype-based dietary and physical-activity advice: impact on health behavior

AIM

To assess the behavioral effects of receiving personal genetic information, using apoE genotypes as a tool for promoting lifestyle changes. apoE was chosen because it has a significant impact on lipid metabolism and cholesterol absorption, both factors in cardiovascular disease.

METHODS

This study was a 1-year intervention study of healthy adults aged 20-67 years (n = 107). Their behavioral changes were measured by diet (e.g., fat quality, as well as consumption of vegetables, berries, fruits, and fatty and sugary foods), alcohol consumption, and exercise. Health and taste attitudes were assessed with the Health and Taste Attitude Scales (HTAS). The measurements were performed 4 times: at baseline (T0), as well as 10 weeks (T1), 6 months (T2), and 12 months after baseline (T3). These behavioral effects were assessed for three groups: a high-risk (Ɛ4+; n = 16), a low-risk (Ɛ4-; n = 35), and a control group (n = 56).

RESULTS

Personal genetic information affected health behavior. Dietary fat quality improved more in the Ɛ4+ group than in the Ɛ4- and control groups after personal, genotype-based health advice. This change differed significantly between the Ɛ4+ and the control group (p < 0.05), but only for a short time.

CONCLUSION

Personal genetic information, based on apoE, may affect dietary fat quality. More research is required to determine how to utilize genotype-based health information and how to efficiently achieve long-term changes in the prevention of lifestyle-related diseases.

Inhibition of Angiotensin converting enzyme I caused by autolysis of potato proteins by enzymatic activities confined to different parts of the potato tuber

Autolysis of protein isolates from vascular bundle and inner tuber tissues of potato (Solanum tuberosum) enhanced the inhibition of the angiotensin converting enzyme I (ACE), a biochemical factor affecting blood pressure (hypertension). The physiological age of the tuber affected the strength of ACE inhibition, the rate of its increase during autolysis, and the tuber tissue where ACE inhibition was most pronounced. The highest inhibitory activities (50% reduction in ACE activity achieved following autolysis at a protein concentration of 0.36 mg mL (-1)) were measured in tubers after 5-6 months of storage prior to sprouting. The rate of ACE inhibition was positively correlated with protease activity in tuber tissues. Amendment of the autolysis reaction with protein substrates from which bioactive ACE-inhibitory peptides may be released, for example, a purified recombinant protein or a concentrate of total tuber proteins, also enhanced ACE inhibition. Many tuber proteins including aspartic protease inhibitors were degraded during autolysis. The data provide indications of differences in the enzymatic activities confined to different parts of the potato tuber at different physiological stages. Results suggest that native enzymes and substrate proteins of potato tubers can be utilized in search of dietary tools to manage elevated blood pressure.

Autoxidation of conjugated linoleic acid methyl ester in the presence of alpha-tocopherol: the hydroperoxide pathway

Autoxidation of conjugated linoleic acid (CLA) methyl ester follows at least partly Farmer's hydroperoxide theory. A mechanism for this hydroperoxide pathway has been proposed based on autoxidation of 9-cis,11-trans-CLA methyl ester. This investigation aims at confirming and further clarifying the mechanism by analyzing the hydroperoxides produced from 10-trans,12-cis-CLA methyl ester and by theoretical calculations. Five methyl hydroxyoctadecadienoates were isolated by HPLC and characterized by UV, GC-MS, and 1D- and 2D-NMR techniques. In addition, an HPLC method for the separation of the intact hydroperoxides was developed. The autoxidation of 10-trans,12-cis-CLA methyl ester in the presence of high amount of alpha-tocopherol (20%) was diastereoselective in favor of one geometric isomer, namely Me 9-OOH-10t,12c, and produced new positional isomers 10- and 14-hydroperoxides (Me 10-OOH-11t,13t; Me 14-OOH-10t,12c; and Me 14-OOH-10t,12t). Importantly, one of these new isomers, which was characterized as an intact hydroperoxide, had an unusual cis,trans geometry where the cis double bond is adjacent to the hydroperoxyl-bearing methine carbon. Further insight to the mechanism was provided by calculating the relative energies for different conformations of the precursor lipid, the allylic carbon-hydrogen bond dissociation enthalpies, and the spin distributions on the intermediate pentadienyl radicals. As a result, a better understanding of the isomeric distribution of the product hydroperoxides was achieved and a modified mechanism that accounts for these calculations is presented.

Effect of sesamin on serum cholesterol and triglycerides levels in LDL receptor-deficient mice

Background

Sesamin, a major lignan from sesame seeds has been associated with cholesterol reduction in previous reports, but recent studies suggested differences in the response to sesamin intake depending on the model studied as well as the nature of the sesamin preparation used.

Aim

The effect of pure sesamin epimer on serum lipids was studied in hypercholesterolemic LDL receptor-knockout mice under cholesterol fed condition.

Design

Animals were randomly assigned to 4 groups, fed an atherogenic diet containing stanol ester, sesamin, combination of stanol ester and sesamin or a control diet with no additions.

Results

The control group showed an almost 3-fold increase in serum cholesterol levels due to the atherogenic diet but no effect was seen for triglyceride levels. Stanol ester alone or together with sesamin significantly attenuated the elevation of the cholesterol levels.

Conclusion

Sesamin alone did not affect the elevation of the diet-induced cholesterol level and it did not enhance the effect of stanol ester.

Stereochemistry of the hydroperoxides formed during autoxidation of CLA methyl ester in the presence of alpha-tocopherol

The initial steps in the autoxidation of CLA methyl ester are poorly understood. The aim of this study was to determine the stereochemistry of the hydroperoxides formed during autoxidation of CLA methyl ester in the presence of a good hydrogen atom donor. For this purpose, 9-cis,11-trans CLA methyl ester was autoxidized in the presence of alpha-tocopherol under atmospheric oxygen at 40 degrees C in the dark. The CLA methyl ester hydroperoxides were isolated, reduced to the corresponding hydroxy derivatives, and separated by HPLC. The stereochemistry of seven hydroxy-CLA methyl esters was investigated. The position of the hydroxy group was determined by GC-MS. The geometry as well as the position of the double bonds in the alkyl chain was determined by NMR. In addition, the 13C NMR spectra of six hydroxy-CLA methyl esters were assigned using COSY, gradient heteronuclear multiple bond correlation, gradient heteronuclear single quantum correlation, and total correlation spectroscopy experiments. The autoxidation of 9-cis,11-trans CLA methyl ester in the presence of a good hydrogen atom donor is stereoselective in favor of one geometric isomer, namely the 13-(R,S)-hydroperoxy-9-cis,11-trans-octadecadienoic acid methyl ester. Three types of conjugated diene hydroperoxides are formed as primary hydroperoxides: trans,trans hydroperoxides (12-OOH-8t,10t and 9-OOH-10t,12t), a cis,trans hydroperoxide with the trans double bond adjacent to the hydroperoxide-bearing carbon atom (13-OOH-9c,11t), and a new type of cis,trans lipid hydroperoxide with the cis double bond adjacent to the hydroperoxide-bearing carbon atom (8-OOH-9c,11t). In addition, three nonkinetic hydroperoxides (13-OOH-9t,11t, 8-OOH-9t,11t, and 9-OOH-10t,12c) are formed. This study supports the theory that CLA methyl ester autoxidizes at least partly through an autocatalytic free radical reaction. The complexity of the hydroperoxide mixture is due to formation of two different pentadienyl radicals. Moreover, the stereoselectivity in favor of one geometric isomer can be explained by the selectivity of the two previous steps: the preferential formation of a W-conformer of the pentadienyl radical over the Z-conformer, and regioselectivity of the oxygen addition to the pentadienyl radical.

Antimicrobial properties of phenolic compounds from berries

AIMS

To investigate the antimicrobial properties of phenolic compounds present in Finnish berries against probiotic bacteria and other intestinal bacteria, including pathogenic species.

METHODS AND RESULTS

Antimicrobial activity of pure phenolic compounds representing flavonoids and phenolic acids, and eight extracts from common Finnish berries, was measured against selected Gram-positive and Gram-negative bacterial species, including probiotic bacteria and the intestinal pathogen Salmonella. Antimicrobial activity was screened by an agar diffusion method and bacterial growth was measured in liquid culture as a more accurate assay. Myricetin inhibited the growth of all lactic acid bacteria derived from the human gastrointestinal tract flora but it did not affect the Salmonella strain. In general, berry extracts inhibited the growth of Gram-negative but not Gram-positive bacteria. These variations may reflect differences in cell surface structures between Gram-negative and Gram-positive bacteria. Cloudberry, raspberry and strawberry extracts were strong inhibitors of Salmonella. Sea buckthorn berry and blackcurrant showed the least activity against Gram-negative bacteria.

CONCLUSION

Different bacterial species exhibit different sensitivities towards phenolics.

SIGNIFICANCE AND IMPACT OF THE STUDY

These properties can be utilized in functional food development and in food preservative purposes.

Aging in Pinus sylvestris L. seeds: changes in viability and lipids

Aging of Scots pine seeds (Pinus sylvestris L.) leads to changes in seed quality, such as loss of germinability, delayed growth and abnormality in developing seedlings. The knowledge of biochemical changes responsible for these aging processes is plentiful in some seeds, which are of world-wide interest, but for pine seeds these studies are rare. The aim of the present study, was to analyse pine seeds of varying ages in order to identify biochemical changes occurring in aged pine seeds, and to see if a correlation existed between these results and traditionally used seed-quality parameters, such as germinability and electrolyte leakage.

Antimicrobial effects of Finnish plant extracts containing flavonoids and other phenolic compounds

Plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. Antimicrobial screening of 13 phenolic substances and 29 extracts prepared from Finnish plant materials against selected microbes was conducted in this study. The tests were carried out using diffusion methods with four to nine microbial species (Aspergillus niger, Bacillus subtilis, Candida albicans, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Staphylococcus aureus and Staphylococcus epidermidis). Flavone, quercetin and naringenin were effective in inhibiting the growth of the organisms. The most active plant extracts were purple loosestrife (Lythrum salicaria L.) against Candida albicans, meadowsweet (Filipendula ulmaria (L.) Maxim.), willow herb (Epilobium angustifolium L.), cloudberry (Rubus chamaemorus L.) and raspberry (Rubus idaeus L.) against bacteria, and white birch (Betula pubescens Ehrh.), pine (Pinus sylvestris L.) and potato (Solanum tuberosum. L.) against gram-positive Staphylococcus aureus.

Separation of linoleic acid oxidation products by micellar electrokinetic capillary chromatography and nonaqueous capillary electrophoresis

In this work the suitability of micellar electrokinetic capillary chromatography (MEKC) and nonaqueous capillary electrophoresis (CE) to the analysis of the primary oxidation products of linoleic acid was studied with uncoated fused-silica capillaries. The primary autoxidation products of linoleic acid are the four hydroperoxide isomers 13-hydroperoxy-cis-9, trans-11-octadecadienoic acid, 13-hydroperoxy-trans-9, trans-11-octadecadienoic acid, 9-hydroperoxy-trans-10,cis-12-octadecadienoic acid, 9-hydroperoxy-trans-10, trans-12-octadecadienoic acid. Addition of a surfactant such as sodium dodecyl sulfate (SDS) or sodium cholate (SC) into the running buffer (20-30 mM 3-(cyclohexylamino)-1-propanesulfonic acid (CAPS) or ammonium acetate, pH 9.5-11) was required to enhance the water solubility of the sample and selectivity of the separation. MEKC proved to be a promising new technique for the separation of the primary oxidation products of lipids giving results comparable to high performance liquid chromatography (HPLC). Partial separation of hydroperoxide isomers was also achieved using nonaqueous CE with methanol-acetonitrile-sodium cholate as running buffer.

Effects of alpha- and gamma-tocopherols on the autooxidation of purified sunflower triacylglycerols

The antioxidant effects of alpha- and gamma-tocopherols were evaluated in a model system based on the autooxidation of purified sunflower oil (p-SFO) triacylglycerols at 55 degrees C for 7 d. Both tocopherols were found to cause more than 90% reduction in peroxide value when present at concentrations >20 ppm. Alpha-tocopherol was a better antioxidant than gamma-tocopherol at concentrations < or =40 ppm but a worse antioxidant at concentrations >200 ppm. Neither alpha- nor gamma-tocopherol showed a prooxidant effect at concentrations as high as 2000 ppm. The amount of tocopherols consumed during the course of oxidation was positively correlated to the initial concentration of tocopherols, and the correlation was stronger for alpha- than for gamma-tocopherol. This correlation suggested that, besides reactions with peroxyl radicals, destruction of tocopherols may be attributed to unknown side reactions. Addition of FeSO4, as a prooxidant, caused a 12% increase in the peroxide value of p-SFO in the absence of tocopherols. When tocopherols were added together with FeSO4, some increase in peroxide value was observed for samples containing 200, 600 or 1000 ppm of alpha- but not gamma-tocopherol. The addition of FeSO4, however, caused an increase in the amount of alpha- and gamma-tocopherols destroyed and led to stronger positive correlations between the amount of tocopherols destroyed during oxidation and initial concentration of tocopherols. No synergistic or antagonistic interaction was observed when alpha- and gamma-tocopherols were added together to autooxidizing p-SFO.