63 research outputs found
Green and White Asparagus (Asparagus officinalis): A Source of Developmental, Chemical and Urinary Intrigue
Asparagus (Asparagus officinalis) is one of the world’s top 20 vegetable crops. Both green and white shoots (spears) are produced; the latter being harvested before becoming exposed to light. The crop is grown in nearly all areas of the world, with the largest production regions being China, Western Europe, North America and Peru. Successful production demands high farmer input and specific environmental conditions and cultivation practices. Asparagus materials have also been used for centuries as herbal medicine. Despite this widespread cultivation and consumption, we still know relatively little about the biochemistry of this crop and how this relates to the nutritional, flavour, and neutra-pharmaceutical properties of the materials used. To date, no-one has directly compared the contrasting compositions of the green and white crops. In this short review, we have summarised most of the literature to illustrate the chemical richness of the crop and how this might relate to key quality parameters. Asparagus has excellent nutritional properties and its flavour/fragrance is attributed to a set of volatile components including pyrazines and sulphur-containing compounds. More detailed research, however, is needed and we propose that (untargeted) metabolomics should have a more prominent role to play in these investigations
Effect of post-harvest conditions on antioxidant enzyme activity in Dunaliella tertiolecta biomass
Microalgae biomass is considered a sustainable feedstock to produce high-value compounds including enzymatic and non-enzymatic antioxidants, which are widely used for food, pharmaceuticals, textile, leather, and in the chemical industries. Suitable post-harvest storage conditions to minimise deterioration of enzyme activity is therefore crucial. In this study, the effect of storage temperature over time on antioxidant enzyme activity (catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) in four D. tertiolecta samples (whole wet cells, freeze-dried whole cells, crude extract and freeze-dried crude extract) were evaluated. Antioxidant enzyme activities in freshly harvested whole cells or in the crude extract stored at -20 °C were retained only for up to one month but when stored at -80 °C, both CAT and SOD activities remained unchanged for four months. Moreover, in the freeze dried whole cell samples, CAT and SOD activities were retained for 8 months at -20 °C, however, when a crude extract was prepared and freeze dried, enzyme activities decreased. Therefore, careful control of storage temperature could prevent unfavourable changes to antioxidant activity in harvested cells thereby increasing shelf-life and the value of this type of biomass. This study recommends a suitable post-harvest storage temperature for preservation of Dunaliella biomass for both short-term and long-term stability of antioxidant enzyme activities. Our results strongly indicate that fresh whole cell extracts should be used in antioxidant enzyme assays, but if storage is necessary, whole fresh cells should be freeze dried and stored at -80 °C. Crude extracts prepared should be used in antioxidant enzyme assays within 24 h of preparation
Effect of processing and cooking on total and soluble oxalate content in frozen root vegetables prepared for consumption
The oxalate content of beetroot, carrot, celeriac and parsnip after freezing by traditional and modified methods (the latter resulting in a convenience food product), and after the preparation of frozen products for consumption was evaluated. The highest content of total and soluble oxalates (105 and 82 mg 100 g-1 fresh matter) was found in beetroot. The lowest proportion (55%) of soluble oxalates was noted in celeriac; this proportion was higher in the remaining vegetables, being broadly similar for each of them. Blanching brought about a significant decrease in total and soluble oxalates in fresh vegetables. Cooking resulted in a higher loss of oxalates. The level of oxalates in products prepared for consumption directly after freezing approximated that before freezing. Compared with the content before freezing, vegetables prepared for consumption by cooking after frozen storage contained less oxalates, except for total oxalates in parsnip and soluble oxalates in beetroot and celeriac. The highest ratio of oxalates to calcium was found in raw beetroot; it was two times lower in raw carrot; five times lower in raw celeriac; and eight times lower in raw parsnip. These ratios were lower after technological and culinary processing. The percentage of oxalate bound calcium depended on the species; this parameter was not significantly affected by the procedures applied. The true retention of oxalates according to Judprasong et al. (2006) was lower than retention calculated taking its content in 100 g fresh matter into account.
Source data - Differences in the range of thermoneutral zone between mouse strains - potential effects on translational research
<p>1. Data of Resting Metabolic Rate (RMR) of random bred (RB) mice and mice divergently selected toward high (H-BMR), and low (L-BMR) Basal Metabolic Rate<br>
RMR of each individual from H-BMR and L-BMR line types was recorded at the following Ta: 34, 32, 26, 23, 18 °C (starting with the warmest to avoid acclimation to cold before the next measurement). RMR of RB mice was sequentially measured at Ta of 34, 32, 28, and 23°C.<br>
2. The thermal conductance (C) of mouse body covers (skin and fur) measured using heated artificial models<br>
The heating wire was connected to a regulated DC power supplier and the model was heated gently to a temperature of 38°C and power was adjusted to maintain 38°C. When supplied power and the model temperature were stable (± 0.1°C) for at least 10 minutes, the voltage (U) and current (I) were recorded and the DC electric power (P) calculated, where P = U x I. </p>
Importance of fat reserves in Wilson´s storm petrel chicks
All petrels store large quantities of fat during nesting period. Several hypotheses have offered explanations for the exceptional accumulation of fat by petrels and that stored in smaller amounts by other birds. Fat reserves of Wilson's storm petrel chicks attain 80% of dry mass. Lipid index increases up to value of 2.0 during nesting period . The aim of our study was to explain the role of fat stores in the nestlings. Stable growth of chicks during first three weeks of life suggests that stochastic variation of chick food provisioning arises from unpredictable snow storms rather than fluctuating food availability at the sea. The lack of correlation between body mass and head, tarsal or wing length rejects hypotheses that chicks accumulate lipid in order to increase their rate of intake of a limiting nutrients. Accumulation of excessive lipid reserves may be a consequence of overfeeding of the chicks by their parents. This strategy protects offspring from death during periods of starvation, when nest entrances are covered by snow
The effect of processing on the amino acid content in green cauliflower
The aim of the work was to evaluate the level of amino acids and quality of protein in fresh green cauliflower and in three kinds of products as eaten: fresh cauliflower after cooking; and two types of frozen product: frozen cauliflower obtained using the traditional method (blanching-freezing-frozen storage-cooking); and by the modified method (cooking-frozen storage-defrosting-heating in a microwave oven). Frozen products were stored for 12 months at -20 °C. Fresh inflorescences contained 24.32 g amino acids in 1 kg of edible parts. Expressed as g per 16 g N the content was 86.59 g, with essential amino acids constituting 44%. Culinary processing and the freezing process did not result in a drastic decrease in amino acid content apart from tyrosine. For all the samples the limiting amino acids of the first order was cystine with methionine and of the second order leucine.vo
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