Proceedings of the 16th Weurman Flavour Research Symposium

Oats are increasingly popular due to their healthiness, and the number of new different types of oat products on the market is constantly increasing. Oats have higher content of lipids compared to many other grains and therefore their quality and volatile compound profile is susceptible to changes. In this study, selected oat samples were investigated using HS-SPME-GC-O panel and trained sensory panel in order to identify the compounds contributing to the odour characteristics. GC-O panel was trained to describe odours and to evaluate odour intensities of oat samples as flour-water mixtures. The odour and flavour characteristics of the same oat samples were characterised using a sensory panel using generic descriptive analysis. The GC-O panel detected 30 odour-active compounds. The most often described compounds were aldehydes, such as hexanal described as ‘green’ and ‘grassy’, or 3-methylbutanal described as ‘chemical’ and ‘pungent’. At the same time, little differences were observed in ‘green odour’ by the sensory panel, whereas more differences were observed in bitter taste and odour and flavour intensities. </p

Similarity Index for the Fat Fraction between Breast Milk and Infant Formulas

The similarity of the fat fraction in infant formulas rich in either bovine milk fat (MF) or vegetable oil (VO) to breastmilk was evaluated by analyzing their lipid composition. Milk fat-rich formulas were highly similar (average similarity index 0.68) tobreast milk compared to the VO-rich formulas (average similarity index 0.56). The highest difference in the indices was found in thecontents of cholesterol (0.66 vs 0.28 in MF- and VO-rich formulas, respectively, on average) and polar lipids (0.84 vs 0.53), thepositional distribution of fatty acids in thesn-2 position of triacylglycerols (0.53 vs 0.28), and fatty acid composition (0.72 vs 0.54).The VO-based formulas were superior in similarity inn-6 PUFA. Thus, the addition of bovine MF fractions is an effective way toincrease the similarity between the lipid composition of infant formulas and human mil

Tissue-Specific Content of Polyunsaturated Fatty Acids in (n-3) Deficiency State of Rats

The dietary intake of fatty acids (FAs) affects the composition and distribution of FAs in the body. Here, a first-generation (n-3)-deficiency study was conducted by keeping young (age 21 & PLUSMN; 2 days) Sprague-Dawley male rats on a peanut-oil-based diet for 33 days after weaning in order to compare the effect of mild (n-3)-deficiency on the lipid composition of different organs and feces. Soybean-oil-based diet was used as a control. The plasma FA levels corresponded to FAs levels in the organs. Lower docosahexaenoic acid (DHA) content was detected in the plasma, brain, testis, visceral fat, heart, and lungs of the (n-3)-deficient group, whereas the DHA content of the eye and feces did not differ between the experimental groups. The DHA content of the brains of the (n-3)-deficient group was 86% of the DHA content of the brains of the (n-3)-adequate group. The DHA level of the organs was affected in the order of visceral fat > liver triacylglycerols > lung > heart > liver phospholipids > testis > eye > brain, with brain being least affected. The low levels of (n-3) FAs in the liver, brain, eye, heart, and lung were offset by an increase in the (n-6) FAs, mainly arachidonic acid. These results indicate that, in rats, adequate maternal nutrition during pregnancy and weaning does not provide enough (n-3) FAs for 33 days of an (n-3)-deficient diet. Results of this study can be used also to evaluate the conditions needed to reach mild (n-3) deficiency in the first generation of rats and to evaluate the feasibility to collect data from a variety of organs or only selected ones

Odor-contributing volatile compounds of wild edible Nordic mushrooms analyzed with HS–SPME–GC–MS and HS–SPME–GC–O/FID

Although Nordic wild edible mushrooms offer a wide range of different odors their scientific examination has been scarce. The aim of this study was to characterize the aroma compounds of four Finnish wild mushroom species with trained assessors using gas chromatography–olfactometry as well as gas chromatography–mass spectrometry. Headspace volatiles were extracted from sous vide cooked mushroom samples (Boletus edulis, Lactarius camphoratus, Cantharellus cibarius and Craterellus tubaeformis) using solid-phase microextraction. Odor-contributing compounds were measured with two columns of differing polarity using the detection frequency method. Compounds were identified based on reference compounds, linear retention indices, odor descriptions, and mass spectrometry. Both the volatile compound profiles and the aromagrams were distinct with characteristic compounds for each species. The results demonstrate that especially saturated and unsaturated aldehydes and ketones contribute to the odor of the studied wild mushrooms. This thorough comparison also indicates compounds linked to the sensory properties of mushrooms.</p

Strategy for stereospecific characterization of natural triacylglycerols using multidimensional chromatography and mass spectrometry

Stereoisomeric determination of individual triacylglycerols (TAGs) in natural oils and fats is a challenge due to similar physicochemical properties of TAGs with different fatty acid combinations. In this study, we present a strategy to resolve the enantiomeric composition of nutritionally important TAGs in sea buckthorn (Hippopha & euml; rhamnoides) as an example food matrix. The targeted strategy combines 1) fatty acid profiling with GC, 2) separation of TAGs with RP-HPLC, 3) stereospecific separation with chiral-phase HPLC and 4) structural characterization with MS. Three major asymmetric diacid-and triacid-TAG species were analyzed in sea buckthorn pulp oil. Off-line coupling of RP-HPLC and chiral-phase HPLC allowed separation of several TAG regioisomers and enantiomers, which could not be resolved using one-dimensional techniques. Enantiomeric ratios were determined and specific structural analysis of separated TAGs was performed using direct inlet ammonia negative ion chemical ionization method.Of the TAG 16:0/16:1/16:1 palmitic acid (C16:0) was located predominantly in a primary position and the enantiomeric ratio of TAG sn-16:1-16:1-16:0 to sn-16:0-16:1-16:1 was 70.5/29.5. Among the TAGs 16:0/16:0/18:2 and 16:0/16:0/16:1, only ca 5% had C16:0 in the sn-2 position, thus, ca 95% were symmetric sn-16:0-18:2-16:0 and sn-16:0-16:1-16:0. The enantiomeric ratio of triacid-TAGs containing C16:0 and two unsaturated fatty acids (palmitoleic C16:1, oleic C18:1 or linoleic acids C18:2) could not be resolved due to lack of commercial enantiopure reference compounds. However, it became clear that the targeted strategy presented offer unique and convenient method to study the enantiomeric structure of individual TAGs.(c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/

Oxidative stability, oxidation pattern and α-tocopherol response of docosahexaenoic acid (DHA, 22:6n-3)-containing triacylglycerols and ethyl esters

DHA is most often used in supplements either in its triacylglycerol or ethyl ester form. Currently, there is only little published data on the differences in the oxidative stability and α-tocopherol response between the two lipid structures, as well as on the oxidation patterns of pure DHA. This study investigated the oxidative stability, α-tocopherol response and oxidation pattern of DHA incorporated in triacylglycerols and as ethyl esters with an untargeted approach after oxidation at 50 °C in the dark. Liquid and gas chromatographic methods with mass spectrometric detection and nuclear magnetic resonance spectroscopy were applied. DHA was more stable in triacylglycerols than as ethyl esters without α-tocopherol addition. With α-tocopherol added the opposite was observed. The oxidation products formed during triacylglycerol and ethyl ester oil oxidation were mostly similar, but also some structure-related differences were detected in both volatile and non-volatile oxidation products

Effect of oat or rice flour on pulse-induced gastrointestinal symptoms and breath hydrogen in subjects sensitive to pulses and controls - a randomised cross-over trial with two parallel groups

Pulses are healthy and sustainable but induce gut symptoms in people with a sensitive gut. Oats, on the contrary, have no fermentable oligo- di-, monosaccharides and polyols compounds and are known for the health effects of their fibres. This 4-day cross-over trial investigated the effects of oat and rice flour ingested with pulses on gut symptoms and exhaled gases (4th day only) in subjects with a sensitive gut or IBS (n 21) and controls (n 21). The sensitive group perceived more symptoms after both meals than controls (P = 0 center dot 001, P = 0 center dot 001). Frequency, intensity or quality of the symptoms did not differ between meals during the first 3 d in either group. More breath hydrogen was produced after an oat than rice containing meal in both groups (AUC, P = 0 center dot 001, P = 0 center dot 001). No between-group difference was seen in breath gases. During day 4, both sensitive and control groups perceived more symptoms after the oat flour meal (P = 0 center dot 001, P = 0 center dot 0104, respectively) as mainly mild flatulence. No difference in moderate or severe symptoms was detected. Increased hydrogen production correlated to a higher amount of perceived flatulence after the oat flour meal in both the sensitive and the control groups (P = 0 center dot 042, P = 0 center dot 003, respectively). In summary, ingestion of oat flour with pulses increases breath hydrogen levels compared with rice flour, but gastrointestinal symptoms of subjects sensitive to pulses were not explained by breath hydrogen levels. Additionally, consumer mindsets towards pulse consumption and pulse-related gut symptoms were assessed by an online survey, which implied that perceived gut symptoms hinder the use of pulses in sensitive subjects

Baltic herring (Clupea harengus membras) oil encapsulation by spray drying using a rice and whey protein blend as a coating material

As popular coating material for encapsulation like milk proteins and maltodextrin do not fully mask unpleasant fish flavors, rice and whey protein blend was tested to aid the use of Baltic herring (BH) oil in functional foods. Particle size and morphology of emulsions (7.5% whey protein, 7.5% rice protein, 15% BH oil and water) produced at pH 3, 6 or 8 with one or two step homogenization and resulting powders were characterized together with fatty acid composition, volatile compounds and oxidative stability. The use of rice and whey proteins lead to stable emulsions with bimodal size distribution and large dispersion (0.05-100 mu m). Emulsion's pH affected powder particle sizes, with pH 3 resulting in powders with biggest particle sizes. Morphology of powders showed spherical shape with porous structure. Emulsions with pH 6.5 produced powders with the highest induction periods (1.59-1.73 h) and low content of volatile compounds