Maaria Kortesniemi

Analysis of hydrolyzable tannins and other phenolic compounds in emblic leafflower (Phyllanthus emblica L.) fruits by high performance liquid chromatography-electrospray ionization mass spectrometry.

Phenolic compounds were extracted from dried emblic leafflower (Phyllanthus emblica L.) fruits with methanol and separated by Sephadex LH-20 column chromatography. The raw extracts and fractions were analyzed with HPLC coupled with diode array UV spectroscopy, electrospray ionization mass spectrometry, and tandem mass spectrometry. Mucic acid gallate, mucic acid lactone gallate, monogalloylglucose, gallic acid, digalloylglucose, putranjivain A, galloyl-HHDP-glucose, elaeocarpusin, and chebulagic acid were suggested to be the most abundant compounds in the crude methanol extracts of the fruits. In addition, 144 peaks were detected, of which 67 were tentatively identified mostly as ellagitannins, flavonoids, and simple gallic acid derivatives in the fractions. The results indicated the presence of neochebulagic acid, isomers of neochebuloyl galloylglucose, chebuloyl neochebuloyl galloylglucose, ellagic acid glycosides, quercetin glycosides, and eriodictyol coumaroyl glycosides in the fruits. The study provides a systematic report of the retention data and characteristics of UV, MS, and MS/MS spectra of the phenolic compounds in the fruits of emblic leafflower. The fruits of two varieties (Ping Dan No 1 and Fruity) from Guangxi Province differed from those of wild Tian Chuan emblic leafflower from Fujian Province in the content and profile of phenolic compounds.

NMR metabolomics of ripened and developing oilseed rape (Brassica napus) and turnip rape (Brassica rapa)

The oilseeds of the commercially important oilseed rape (Brassica napus) and turnip rape (Brassica rapa) were investigated with (1)H NMR metabolomics. The compositions of ripened (cultivated in field trials) and developing seeds (cultivated in controlled conditions) were compared in multivariate models using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA). Differences in the major lipids and the minor metabolites between the two species were found. A higher content of polyunsaturated fatty acids and sucrose were observed in turnip rape, while the overall oil content and sinapine levels were higher in oilseed rape. The genotype traits were negligible compared to the effect of the growing site and concomitant conditions on the oilseed metabolome. This study demonstrates the applicability of NMR-based analysis in determining the species, geographical origin, developmental stage, and quality of oilseed Brassicas.

1H NMR spectroscopy reveals the effect of genotype and growth conditions on composition of sea buckthorn (Hippophaë rhamnoides L.) berries

¹H NMR spectroscopy and multivariate data analysis were applied to the metabolic profiling and discrimination of wild sea buckthorn (Hippophaë rhamnoides L.) berries from different locations in Finland (subspecies (ssp.) rhamnoides) and China (ssp. sinensis). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) showed discrimination of the two subspecies and different growth sites. The discrimination of ssp. rhamnoides was mainly associated with typically higher temperature, radiation and humidity and lower precipitation in the south, yielding higher levels of O-ethyl β-d-glucopyranoside and d-glucose, and lower levels of malic, quinic and ascorbic acids. Significant metabolic differences (p<0.05) in genetically identical berries were observed between latitudes 60° and 67° north in Finland. High altitudes (> 2,000 m) correlated with greater levels of malic and ascorbic acids in ssp. sinensis. The NMR metabolomics approach applied here is effective for identification of metabolites, geographical origin and subspecies of sea buckthorn berries.

Coordinate changes in gene expression and triacylglycerol composition in the developing seeds of oilseed rape (Brassica napus) and turnip rape (Brassica rapa)

Crop production for vegetable oil in the northern latitudes utilises oilseed rape (Brassica napus subsp. oleifera) and turnip rape (B. rapa subsp. oleifera), having similar oil compositions. The oil consists mostly of triacylglycerols, which are synthesised during seed development. In this study, we characterised the oil composition and the expression levels of genes involved in triacylglycerol biosynthesis in the developing seeds in optimal, low temperature (15 °C) and short day (12-h day length) conditions. Gene expression levels of several genes were altered during seed development. Low temperature and short day treatments increased the level of 9,12,15-octadecatrienoic acid (18:3n-3) in turnip rape and short day treatment decreased the total oil content in both species. This study gives a novel view on seed oil biosynthesis under different growth conditions, bringing together gene expression levels of the triacylglycerol biosynthesis pathway and oil composition over a time series in two related oilseed species.

Stability of Hydroxycinnamic Acid Derivatives, Flavonol Glycosides, and Anthocyanins in Black Currant Juice

The stability of phenolic compounds was followed in black currant juice at ambient temperatures (in light and in dark conditions) and at +4 °C for a year. Analyses were based on high-performance liquid chromatography-diode-array detection-electrospray ionization-mass spectrometry (or tandem mass spectrometry) and high-performance liquid chromatography-diode-array detection-electrospray ionization-quadrupole time-of-flight mass spectrometry methods supported by nuclear magnetic resonance after selective high-performance liquid chromatography isolation. Altogether, 43 metabolites were identified, of which 2-(Z)-p-coumaroyloxymethylene-4-β-d-glucopyranosyloxy-2-(Z)-butenenitrile, 2-(E)-caffeoyloxymethylene-4-β-d-glucopyranosyloxy-2-(Z)-butenenitrile, 1-O-(Z)-p-coumaroyl-β-d-glucopyranose, (Z)-p-coumaric acid 4-O-β-d-glucopyranoside, and (Z)-p-coumaric acid were novel findings in black currant juice. Hydroxycinnamic acid derivatives degraded 20-40% at room temperature during one year of storage, releasing free hydroxycinnamic acids. O-Glucosides of hydroxycinnamic acid compounds were the most stable, followed by O-acylquinic acids, acyloxymethyleneglucosyloxybutenenitriles, and O-acylglucoses. Light induced the isomerization of (E)-coumaric acid compounds into corresponding Z-isomers. Flavonol glycosides stayed fairly stable. Flavonol aglycones were derived mainly from malonylglucosides. Over 90% of anthocyanins were lost at room temperature in a year, practically independent of light. Storage at low temperatures, preferably excluding light, is necessary to retain the original composition of phenolic compounds.

Comparison of the postprandial effects of purple-fleshed and yellow-fleshed potatoes in healthy males with chemical characterization of the potato meals

Abstract The aim of the current study was to characterize the anthocyanin content and composition of a purple potato landrace cultivar (Solanum tuberosum ‘Synkeä Sakari’) and to compare the postprandial effects of purple-fleshed potatoes, yellow-fleshed potatoes and bilberries in potato starch on postprandial glycemia and insulinemia in healthy males. The purple potato meal caused smaller insulinemia than the yellow potato meal (iAUC 120 min 1347 and 2226, respectively, p = 0.012 and iAUC 240 min 1448 and 2403, p = 0.007) or the bilberry meal (iAUC 120 min 1920, p = 0.027). The purple potato meal caused a smaller plasma glucose at 40 min postprandially compared with the yellow potato meal (p = 0.044). The results of this study suggest that anthocyanin-containing purple-fleshed potatoes influence the postprandial insulinemia positively. Since potatoes are the world’s largest non-grain commodity, replacing yellow-fleshed potatoes with purple-fleshed potatoes as staple food could have large potential in maintaining public health.

Chemical composition of bilberry wine fermented with non-Saccharomyces yeasts (Torulaspora delbrueckii and Schizosaccharomyces pombe) and Saccharomyces cerevisiae in pure, sequential and mixed fermentations

This study evaluated the effects of fermentation with pure cultures of Torulaspora delbrueckii (TD291 and TD70526) and Schizosaccharomyces pombe (SP3796 and SP70572), as well as in sequential and mixed inoculations with Saccharomyces cerevisiae, on the chemical composition of bilberry wine. In comparison to the bilberry wines produced by pure and sequential fermentations, mixed cultures produced bilberry wines with more ethanol, higher pH values, higher percentages of red and yellow shade, but less glycerol and acetaldehyde. Higher values of color intensity and bluish parameter were found in products of pure fermentations with non-Saccharomyces yeasts. Compared to S. cerevisiae, T. delbrueckii contributed to the reduction of ethanol and acetic acid while increasing the content of succinic acid, lactic acid and higher alcohols; S. pombe consumed malic acid almost completely and produced more glycerol, acetaldehyde and/or pyruvic acid. Fermentation with SP70572 had the highest amounts of anthocyanins and hydroxycinnamic acids derivatives.

Profiles of Volatile Compounds in Blackcurrant (Ribes nigrum) Cultivars with a Special Focus on the Influence of Growth Latitude and Weather Conditions

The volatile profiles of three blackcurrant (Ribes nigrum L.) cultivars grown in Finland and their responses to growth latitude and weather conditions were studied over an 8 year period by headspace solid-phase microextraction (HS-SPME) followed by gas-chromatographic–mass-spectrometric (GC-MS) analysis. Monoterpene hydrocarbons and oxygenated monoterpenes were the major classes of volatiles. The cultivar ‘Melalahti’ presented lower contents of volatiles compared with ‘Ola’ and ‘Mortti’, which showed very similar compositions. Higher contents of volatiles were found in berries cultivated at the higher latitude (66° 34′ N) than in those from the southern location (60° 23′ N). Among the meteorological variables, radiation and temperature during the last month before harvest were negatively linked with the volatile content. Storage time had a negative impact on the amount of blackcurrant volatiles.

Enzymatic Acylation of Anthocyanins Isolated from Alpine Bearberry (Arctostaphylos alpina) and Lipophilic Properties, Thermostability, and Antioxidant Capacity of the Derivatives

Cyanidin-3- O-galactoside (cy-gal) isolated from alpine bearberry ( Arctostaphylos alpine L.) was enzymatically acylated with saturated fatty acids of different chain lengths with Candida antarctica lipase immobilized on acrylic resin (Novozyme 435). The acylation reaction was optimized by considering the reaction medium, acyl donor, substrate molar ratio, reaction temperature, and reaction time. The highest conversion yield of 73% was obtained by reacting cy-gal with lauric acid (molar ratio of 1:10) in tert-butanol at 60 °C for 72 h. A novel compound was synthesized, which was identified as cyanidin-3- O-(6″-dodecanoyl)galactoside by mass spectrometry and nuclear magnetic resonance. Introducing lauric acid into cy-gal significantly improved both the lipophilicity and thermostability and substantially preserved the ultraviolet-visible absorbance and antioxidant properties. The research provides important insight in expanding the application of natural anthocyanins in the cosmetic and food industries.

Sensory and chemical profiles of Finnish honeys of different botanical origins and consumer preferences

The sensory-chemical profiles of Finnish honeys (labeled as buckwheat, cloudberry-bog, lingonberry, sweet clover, willowherb and multifloral honeys) were investigated using a multi-analytical approach. The sensory test (untrained panel, n = 62) was based on scaling and check-all-that-apply (CATA) methods accompanied with questions on preference and usage of honey. The results were correlated with corresponding profiles of odor-active compounds, determined using gas chromatography coupled with mass spectrometry/olfactometry (GC-MS/O). Botanical origins and chemical compositions including sugars were evaluated using NMR spectroscopy. A total of 73 odor-active compounds were listed based on GC-O. Sweet and mild honeys with familiar sensory properties were preferred by the panelists (PCA, R2X(1) = 0.7) while buckwheat and cloudberry-bog honeys with strong odor, flavor and color were regarded as unfamiliar and unpleasant. The data will give the honey industry novel information on honey properties in relation to the botanical origin, and consumer preference.