Determination of free and total phenolic acids in plant-derived foods by HPLC with diode-array detection

A high-performance liquid chromatographic (HPLC) method with diode-array detection (DAD) was used to identify and quantify free and total phenolic acids (m-hydroxybenzoic acid, p-hydroxybenzoic acid, protocatechuic acid, gallic acid, vanillic acid, syringic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, ferulic acid, sinapic acid, chlorogenic acid, and ellagic acid) in plant foods. Free phenolic acids were extracted with a mixture of methanol and 10% acetic acid. Bound phenolic acids were liberated using first alkaline and then acid hydrolysis followed by extraction with diethyl ether/ethyl acetate (1:1). All fractions were quantified separately by HPLC. After HPLC quantification, results of alkali and acid hydrolysates were calculated to represent total phenolic acids. Ellagic acid was quantified separately after long (20 h) acid hydrolysis. The methods developed were effective for the determination of phenolic acids in plant foods. DAD response was linear for all phenolic acids within the ranges evaluated, with correlation coefficients exceeding 0.999. Coefficients of variation for 4-8 sample replicates were consistently below 10%. Recovery tests of phenolic acids were performed for every hydrolysis condition using several samples. Recoveries were generally good (mean >90%) with the exceptions of gallic acid and, in some cases, caffeic acid samples.     

Risk assessment for volunteer and seedling GM potatoes in the northernmost European growing areas

Abstract

Commercial production of genetically modified (GM) potatoes (Solanum tuberosum L.) could represent a risk to conventional production if volunteer plants develop from tubers or true seeds that survive until the following growing season. We studied such risks under northernmost European conditions and monitored the effects of cultivar, tuber size and tuber depth in the soil on winter survival at MTT Agrifood Research Finland, Jokioinen (61°06′N, 23°02′E) from 2004–2007. Tubers of two non-GM cultivars, Saturna and Asterix, and two size classes, 25–30 mm and 45–50 mm, were planted at depths of 10 and 20 cm in autumn, soon after harvest. In winters 2004–2005 and 2005–2006 all tubers planted in the soil in autumn were killed by frost. In 2005–2006, the field was covered by up to 30–40 cm of snow and the minimum soil temperatures ranged between ?0.4^oC and ?0.9^oC, but only 0.0–3.5% of the tubers survived and there was no difference between cultivars, tuber sizes and planting depths. Under laboratory conditions compared with ?2.0°C and ?2.5°C, treatment at ?3.0°C for 72 h resulted in significantly lower survival rate of the tubers (8.2%). Asterix, a late maturing table potato cultivar, was more resistant to low temperatures than the processing cultivar Saturna. In general, volunteer tubers are not currently a significant risk for coexistence of GM and conventional potato production in northern Europe due to the cold winter conditions but also due to possibilities to control the sporadic volunteers from the next crop. However, we noted that seedlings initiated from true potato seed are able to produce tubers despite the short growing season. Such a risk could be reduced by accepting only non-berry-producing GM cultivars for cultivation.     

Haemodynamic differences between pancuronium and vecuronium in an experimental pig model

ObjectiveTo compare baseline cardiovascular function in anesthetised pigs using either pancuronium or vecuronium as a neuromuscular blocker.Study designRetrospective, non-randomized comparison.AnimalsNorwegian Land Race pigs (Sus scrofa domesticus) weighing mean 42 ± SD 3 kg.MethodsOne hundred and sixteen animals from four different research protocols premedicated with identical doses of ketamine, diazepam, atropine and isoflurane, and anaesthetised with pentobarbital, fentanyl, midazolam and N₂O were arranged into three uniform groups with respect to neuromuscular blocking agent: pancuronium bolus of 0.063 mg kg⁻¹ followed by 0.14 mg kg⁻¹ hour⁻¹ (n = 54), low-dose vecuronium 0.4 mg kg⁻¹/0.2 mg kg⁻¹ hour⁻¹ (n = 29) and high-dose vecuronium 0.6 mg kg⁻¹/0.3 mg kg⁻¹ hour⁻¹ (n = 33).ResultsThe majority of cardiovascular parameters demonstrated no significant differences between groups. For heart rate, there was an overall group difference, p = 0.036. Dromotropy was low in the pancuronium group, with an increased normalised PR-interval compared to the high-dose vecuronium group, median 0.200 interquartile range (0.190, 0.215) versus 0.182 (0.166, 0.199), p < 0.05. Left ventricular compliance was increased in pancuronium-treated animals, demonstrated as a reduction in the nonlinear end-diastolic pressure volume relationship β compared to both vecuronium groups, 0.021 (0.016, 0.025) versus 0.031 (0.025, 0.046) and 0.031 (0.022, 0.048), p < 0.05. The linear end-diastolic pressure volume relationship EDPVR_lin was reduced as well in the pancuronium group, compared to the low-dose vecuronium group, 0.131 (0.116, 0.169) versus 0.181 (0.148, 0.247), p < 0.05.ConclusionsThere are only minor haemodynamic differences when using pancuronium compared to vecuronium in the fentanyl-pentobarbital-midazolam-N₂O anesthetised domestic pigs. Furthermore, increasing doses of vecuronium have minimal haemodynamic effects.Clinical relevanceExperimental studies in pigs using either pancuronium or vecuronium as a neuromuscular blocking agent are comparable with regard to cardiac and haemodynamic performance.     

Effect of cholecalciferol-enriched hen feed on egg quality

Eggs are one of the most important sources of vitamin D in the human diet, and their vitamin D content can be further increased by adding more vitamin D to hen feed. To investigate this issue more closely, we performed two feeding experiments. In both, zero egg samples were collected while the hens were fed regular feeds with a vitamin D content of 1720 or 4280 IU/kg. In experiment 1, egg samples were collected 2, 4, 7, 9, 11, 13, 16, 23, and 30 days after beginning the high-cholecalciferol (11 200 IU/kg) feeding period. In experiment 2, samples were collected 2, 4, 6, 8, 13, 28, 56, 84, 112, 140, and 168 days after beginning the high-cholecalciferol (12 000 IU/kg) diet. The egg samples were then assayed for their cholecalciferol content, and some samples, also for the presence of 25-hydroxycholecalciferol by an HPLC method. Further, the vitamin D-fortified eggs were compared with the controls by a sensory evaluation, by conducting fatty acid and functional analyses (emulsion capacity, gel forming capacity, foaming properties) and by measuring eggshell strength. Because vitamin D can be toxic in high doses, we also performed histopathological tests on the hens at the end of experiment 2. The top cholecalciferol contents in egg yolk (ca. 30 microg/100 g) were reached 8-13 days from starting the high-cholecalciferol diet. After 112 days feeding the cholecalciferol content gradually decreased to ca. 22 microg/100 g. When added to eggs as described above, vitamin D did not affect their sensory or functional properties or their fatty acid composition. Moreover, the cholecalciferol levels used in this study appeared not to affect eggshell strength or to be harmful for hens.     

Association of growth dynamics, yield components and seed quality in long-term trials covering rapeseed cultivation history at high latitudes

Brassica oilseed yield trend has declined in Finland by over 20% during the last 15 years. Improved genetic yield potential of turnip rape (B. rapa L.) and oilseed rape (B. napus L.) can be better realised with increased understanding of yield determining processes under northernmost growing conditions. This study aimed at (1) determining the genetic improvements in seed yield, yield components, quality traits and duration of the main growth phases and (2) comparing all these traits in turnip rape and oilseed rape. This work is based on the dataset from long-term Official Variety Trials (1976–2006), covering the entire historically relevant period of rapeseed cultivation in Finland. The results indicated that number of seeds per square metre dominated production of high yields, while single seed weight was not correlated with yield. Over the years, seed yields were produced with very different combinations of seed numbers and weights, differing markedly between the two crops. While high seed numbers were required for production of superior seed yields, single seed weights were not particularly high. Environmental variation markedly affected seed yield, seed number per square metre and duration of flowering compared with its effect on single seed weight. Duration of flowering was, however, negatively associated with seed number. Even though seed weight was largely determined by genotype, no marked plant breeding improvements were identified, contrary to those in number of seeds per square metre, seed yield, oil content and oil yield. For oilseed rape the increase in seed yield (41%) was far higher than for turnip rape (19%) without being associated with a longer seed-filling phase and later ripening, but rather the contrary.     

Cereal yield trends in northern European conditions: Changes in yield potential and its realisation

In recent decades there has been steady reduction in the rate of increase in cereal yields worldwide. This paper aims to (1) characterise the changes in yield trends of spring (barley, oat and wheat) and winter cereals (rye and wheat) grown in Finland and (2) distinguish between plant breeding achievements and other potential contributors to changes in national yield trends and differences among crops. In this work we used long-term datasets from FAO (FAOSTAT, 2007) (1960–2005) and results from multi-location MTT Official Variety Trials (1970–2005). A mixed model technique was used to divide the yield trends in variety trials into two components: genetic improvements and environmental changes. All trends were characterised using 5 years moving averages. The study period was divided into three agronomically relevant sub-periods: (1) in 1960–1980 agriculture was mechanised and improved basic agricultural practices largely introduced, (2) in 1981–1994 intensified crop management practices were increasingly applied and (3) in 1995–2005 Finland had joined the European Union, which resulted in altered agricultural policies and markets. Plant breeding has successfully increased genetic yield potential of all cereal crops without any indication of reduced rates of improvement. Since 1995 the Finnish national yield trends declined for all crops except wheat, for which the trend levelled-off. The main reasons for this are: cereal production has become less intensive because of (1) application of an environmental programme aimed at increasing the sustainability of agriculture by reducing the environmental load it represents and (2) markedly decreased economic incentives to produce intensively as producer prices for cereals decreased and input prices remained unchanged. National yield trends did not decline because of lack of genetic improvement in yield potential. It is likely that future cereals yield trends will again respond to increasing demand for food, feed, biofuel production and global climate change.     

The Occurrence of European Brown Hare Syndrome in Finland

European brown hare syndrome (EBHS) is a viral hepatitis that affects European brown hares (Lepus europaeus) and varying hares (Lepus timidus). The disease occurs today in free-living and farmed hares in most European countries (Gustafsson et al. 1989, Gavier-Widén & Mörner 1991). In Sweden and Denmark the EBHS was first observed at the beginning of the eighties, however, in Finland and Norway the disease has not been reported yet.     

Productive oat ideotype for northern growing conditions

Summary Yield formation of four Finnish and three Nordic oat varieties and 12 breeding lines developed at the Hankkija Plant Breeding Institute was studied during four different growing seasons (1986–1989). Seventeen characteristics were measured, including traits representing the date of maturity and architecture of the oat stand. The variation between genotypes in the examined traits was studied by means of two-way analysis of variance. The relationship between grain yield and morpho-physiological traits was studied by means of simple correlation analysis and stepwise regression analysis.The present study, carried out in highly dissimilar growing seasons, showed that ideotype breeding in the northern growing areas is likely to be successful only in moderate to optimal growing conditions. Based on the findings of this study, a productive oat ideotype for northern cultivation is composed of traits such as early maturation, high phytomass production with a high panicle weight resulting from a large number of grains. short straw length (high resistance to lodging), and reduced tillering. The importance of other factors influencing oat breeding in northern growing conditions is discussed.