Volatile compounds and other indicators of quality for cold-pressed rapeseed oils obtained from peeled, whole, flaked and roasted seeds

The Effect of Organic and Conventional Cultivation Systems on the Profile of Volatile Organic Compounds in Winter Wheat Grain, Including Susceptibility to Fusarium Head Blight

The grain of 30 winter wheat cultivars differing in terms of their resistance to FHB (Fusarium head blight) was tested. The cultivars were grown in four variants of field trials established in a split-plot design: control without fungicides, chemical control of FHB with fungicides after Fusarium inoculation, Fusarium head inoculation, and organic cultivation. The profile of volatile compounds in grain samples was determined by mean headspace-solid phase microextraction and analyzed by gas chromatography time-of-flight mass spectroscopy. The identified volatile profile comprised 146 compounds belonging to 14 chemical groups. The lowest abundance of volatile organic compounds (VOCs) was found for the organic cultivation variant. The performed discriminant analysis facilitated the complete separation of grain for individual experimental variants based on the number of VOCs decreasing from 116 through 62, 37 down to 14. The grain from organic farming was characterized by a significantly different VOCs profile than the grain from the other variants of the experiment. The compounds 1-methylcycloheptanol, 2-heptanone, 2(3H)-furanone, and 5-hexyldihydro-2(3H)-furanone showed statistically significant differences between all four experimental variants.

Analysis of volatile organic compounds in Irish rapeseed oils

In recent years, consumer demand for health benefitting, pleasant-tasting rapeseed oil has increased, and so has production. Ireland's climate and agricultural background can support the production of high-quality rapeseed oil. Volatile organic compounds (VOC) can give rise to highly distinctive flavours in rapeseed oils, produced during crop growth and generated during processing. This study performed VOC and sensory evaluation to determine if correlations exist. Samples of Irish rapeseed oils from 6 different producers were analysed. Compounds detected in the oil samples consisted of acids, alcohols, aldehydes, ketones, benzenes, esters, ether, terpenes, and sulphurs. While variations in whole volatile profiles were not considered significant, individual compounds and volatile classes were for hexanal, pentanal, ketones, acids, and sulphurs compounds. Correlations were observed between the VOCs detected and the sensory profile, which indicated the VOC content may influence an oil's sensory profile.

Physicochemical Properties, Fatty Acid Composition, Volatile Compounds of Blueberries, Cranberries, Raspberries, and Cuckooflower Seeds Obtained Using Sonication Method

Every year, thousands of tons of fruit seeds are discarded as agro-industrial by-products around the world. Fruit seeds are an excellent source of oils, monounsaturated fatty acids, and n-6 and n-3 polyunsaturated essential fatty acids. This study aimed to develop a novel technology for extracting active substances from selected seeds that were obtained after pressing fruit juices. The proposed technology involved sonification with the use of ethyl alcohol at a low extraction temperature. Seeds of four species—blueberry (Vaccinium myrtillus L.), raspberry (Rubus idaeus), cranberry (Vaccinium macrocarpon), and cuckooflower (Cardamine pratensis)—were used for extraction. Following alcohol evaporation under nitrogen, the antioxidant activity, chemical composition, and volatile compounds of the obtained extracts were analyzed using chromatographic methods, including gas chromatography (GC)–mass spectrometry (MS) (GC–MS/MS), and high-performance liquid chromatography–MS. We analyzed physicochemical properties, fatty acid, and volatile compounds composition, sterol and tocochromanol content of blueberry, cranberry, raspberry, and cuckooflower seed oils obtained by sonication. This method is safe and effective, and allows for obtaining valuable oils from the seeds.

Flavor of rapeseed oil: An overview of odorants, analytical techniques, and impact of treatment

As one of the three major vegetable oils in the world, rapeseed oil is appreciated for its high nutritional value and characteristic flavor. Flavor is an essential attribute, determining rapeseed oil quality and consumer acceptance. The present manuscript provides a systematic literature review of recent advances and knowledge on the flavor of rapeseed oil, which focuses on aroma-active as well as off-flavor compounds, flavor analysis techniques (i.e., extraction, qualitative, quantitative, sensory, and chemometric methods), and effects of treatments (storage, dehulling, roasting, microwave, flavoring with herbs, refining, and oil heating) on flavor from sensory and molecular perspectives. One hundred thirty-seven odorants found in rapeseed oil from literature are listed and possible formation pathways of some key aroma-active compounds are also proposed. Future flavor analysis techniques will evolve toward time-saving, portability, real-time monitoring, and visualization, which aims to obtain a "complete" flavor profile of rapeseed oil. The changes of volatile compounds in rapeseed oil under different treatments are summarized in this view. Studies to elucidate the influence of different treatments on the formation of aroma-active compounds are needed to get a deeper understanding of factors leading to the variations of rapeseed oil flavor.

Fortified Cold-Pressed Oils: The Effect on Sensory Quality and Functional Properties

The aim of this study was to monitor sensory quality, stability, selected nutritionally interesting properties and their changes in cold-pressed oil blends after fortification with chia and sesame seeds and seed oils during repeated thermal treatments. Rapeseed (cv. Sidney) and sunflower (cv. Velox) seeds from the Czech Republic were used to produce cold-pressed oils, which were fortified with chia and sesame seeds and seed oils in the concentrations of 1% and 5%. In all oil blends, sensory evaluation (quantitative descriptive analysis and hedonic analysis) and chemical analyses (oxidation degree, hydrolytic stability, chlorophyll and carotenoid content) were carried out in order to perform separation of samples degraded by thermal treatment. Assessors representing consumers were able to differentiate between individual thermal treatments from the viewpoint of pleasantness. Interestingly, the overall pleasantness of all fortified oil samples was still acceptable until the second thermal treatment. On the other hand, the results of the study emphasized the problematic oxidation degree of cold-pressed oil blends. The fortification of cold-pressed oils with chia and sesame seeds and oils did not unambiguously lead to better stability during thermal treatment. The application of elevated temperatures during the culinary use of these types of products should be limited to only one thermal treatment since sensory and chemical changes occur after repeated heating.

The Blossoming of Technology for the Analysis of Complex Aroma Bouquets-A Review on Flavour and Odorant Multidimensional and Comprehensive Gas Chromatography Applications

Multidimensional approaches in gas chromatography have been established as potent tools to (almost) attain fully resolved analyses. Flavours and odours are important application fields for these techniques since they include complex matrices, and are of interest for both scientific study and to consumers. This article is a review of the main research studies in the above theme, discussing the achievements and challenges that demonstrate a maturing of analytical separation technology.