The Experts below are selected from a list of 1767 Experts worldwide ranked by ideXlab platform
P K Chattopadhyay - One of the best experts on this subject based on the ideXlab platform.
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effect of process parameters and soy flour concentration on quality attributes and microstructural changes in ready to eat potato soy snack using high temperature short time air Puffing
Lwt - Food Science and Technology, 2008Co-Authors: A Nath, P K ChattopadhyayAbstract:Abstract High-temperature short time (HTST) air Puffing has been found to be very useful process for production of potato–soy ready-to-eat snack food as it ideally produced highly porous and light texture. The process parameters considered viz. Puffing temperature (185–255 °C) and Puffing time (20–60 s) with constant initial moisture content of 36.74% and air velocity of 3.99 m/s for potato–soy blend with varying soy flour content from 5% to 25% were investigated using response surface methodology with central composite rotatable design (CCRD). The optimum product in terms of maximum expansion ratio (3.69), minimum hardness (2754.3 g) and maximum overall acceptability (7.3) were obtained with 10.31% soy flour blend in potato flour at the process conditions of Puffing temperature (230.06 °C) and Puffing time (25.46 s). Microstructural changes were evaluated at different stages (with an interval of 5 s) of HTST Puffing for product obtained with the optimum processing conditions. The maximum expanded porous structures with larger cracks and smaller pits were recorded in the SEM micrographs at 20 s of HTST air Puffing.
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high temperature short time air puffed ready to eat rte potato snacks process parameter optimization
Journal of Food Engineering, 2007Co-Authors: A Nath, P K Chattopadhyay, G C MajumdarAbstract:Ready-to-eat (RTE) potato snacks were developed with high temperature short time (HTST) air Puffing process based on centre composite RSM design. The effects of process parameters viz. Puffing temperature (175-275°C), Puffing time (15-75 s), initial moisture content (30-40%) and air velocity (2.4-4.8 m/s) on quality attributes such as expansion ratio, hardness, ascorbic acid loss and overall acceptability of the products were investigated. The optimum product qualities in terms of expansion ratio (4.7 times), hardness (1120.83 g), ascorbic acid loss (17.53%, db) and overall acceptability (7.56) were obtained at Puffing temperature of 235.46 °C, Puffing time of 51.11 s, initial moisture content of 36.74% and air velocity of 3.99 m/s.
A Nath - One of the best experts on this subject based on the ideXlab platform.
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effect of process parameters and soy flour concentration on quality attributes and microstructural changes in ready to eat potato soy snack using high temperature short time air Puffing
Lwt - Food Science and Technology, 2008Co-Authors: A Nath, P K ChattopadhyayAbstract:Abstract High-temperature short time (HTST) air Puffing has been found to be very useful process for production of potato–soy ready-to-eat snack food as it ideally produced highly porous and light texture. The process parameters considered viz. Puffing temperature (185–255 °C) and Puffing time (20–60 s) with constant initial moisture content of 36.74% and air velocity of 3.99 m/s for potato–soy blend with varying soy flour content from 5% to 25% were investigated using response surface methodology with central composite rotatable design (CCRD). The optimum product in terms of maximum expansion ratio (3.69), minimum hardness (2754.3 g) and maximum overall acceptability (7.3) were obtained with 10.31% soy flour blend in potato flour at the process conditions of Puffing temperature (230.06 °C) and Puffing time (25.46 s). Microstructural changes were evaluated at different stages (with an interval of 5 s) of HTST Puffing for product obtained with the optimum processing conditions. The maximum expanded porous structures with larger cracks and smaller pits were recorded in the SEM micrographs at 20 s of HTST air Puffing.
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high temperature short time air puffed ready to eat rte potato snacks process parameter optimization
Journal of Food Engineering, 2007Co-Authors: A Nath, P K Chattopadhyay, G C MajumdarAbstract:Ready-to-eat (RTE) potato snacks were developed with high temperature short time (HTST) air Puffing process based on centre composite RSM design. The effects of process parameters viz. Puffing temperature (175-275°C), Puffing time (15-75 s), initial moisture content (30-40%) and air velocity (2.4-4.8 m/s) on quality attributes such as expansion ratio, hardness, ascorbic acid loss and overall acceptability of the products were investigated. The optimum product qualities in terms of expansion ratio (4.7 times), hardness (1120.83 g), ascorbic acid loss (17.53%, db) and overall acceptability (7.56) were obtained at Puffing temperature of 235.46 °C, Puffing time of 51.11 s, initial moisture content of 36.74% and air velocity of 3.99 m/s.
G C Majumdar - One of the best experts on this subject based on the ideXlab platform.
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high temperature short time air puffed ready to eat rte potato snacks process parameter optimization
Journal of Food Engineering, 2007Co-Authors: A Nath, P K Chattopadhyay, G C MajumdarAbstract:Ready-to-eat (RTE) potato snacks were developed with high temperature short time (HTST) air Puffing process based on centre composite RSM design. The effects of process parameters viz. Puffing temperature (175-275°C), Puffing time (15-75 s), initial moisture content (30-40%) and air velocity (2.4-4.8 m/s) on quality attributes such as expansion ratio, hardness, ascorbic acid loss and overall acceptability of the products were investigated. The optimum product qualities in terms of expansion ratio (4.7 times), hardness (1120.83 g), ascorbic acid loss (17.53%, db) and overall acceptability (7.56) were obtained at Puffing temperature of 235.46 °C, Puffing time of 51.11 s, initial moisture content of 36.74% and air velocity of 3.99 m/s.
Antony W Diamond - One of the best experts on this subject based on the ideXlab platform.
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From Puffins to Plankton: A DNA-Based Analysis of a Seabird Food Chain in the Northern Gulf of Maine
2016Co-Authors: Kirsten A. Bowser, Antony W Diamond, Jason A. AddisonAbstract:The predator-prey interactions within food chains are used to both characterize and understand ecosystems. Conventional methods of constructing food chains from visual identification of prey in predator diet can suffer from poor taxonomic resolution, misidentification, and bias against small or completely digestible prey. Next-generation sequencing (NGS) technology has become a powerful tool for diet reconstruction through barcoding of DNA in stomach content or fecal samples. Here we use multi-locus (16S and CO1) next-generation sequencing of DNA barcodes on the feces of Atlantic Puffin (Fratercula arctica) chicks (n=65) and adults (n=64) and the stomach contents of their main prey, Atlantic herring (Clupea harengus, n=44) to investigate a previously studied food chain. We compared conventional and molecular-derived chick diet, tested the similarity between the diets of Puffin adults and chicks, and determined whether herring prey can be detected in Puffin diet samples. There was high variability in the coverage of prey groups between 16S and CO1 markers. We identified more unique prey with our 16S compared to CO1 barcoding markers (51 and 39 taxa respectively) with only 12 taxa identified by both genes. We found no significant difference between the 16S-identified diets of Puffin adults (n=17) and chicks (n=41). Our molecular method is more taxonomically resolved and detected chick prey at higher frequencies than conventional field observations. Many likely planktonic prey of herring were detected in feces from Puffin adults and chicks, highlightin
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annual survival of adult atlantic Puffins fratercula arctica is positively correlated with herring clupea harengus availability
Ibis, 2014Co-Authors: Andre R Breton, Antony W DiamondAbstract:Atlantic Herring is a keystone species in several marine ecosystems, supporting intensive fisheries as well as many predators including seabirds. Biomass of this stock in eastern North America has declined considerably in recent years, potentially putting at risk populations of its predators. Although adult survival in seabirds is considered robust to moderate changes in food availability, it is also the life-history component most critical to sustaining populations of long-lived birds. To investigate the possibility that Atlantic Puffin survival has been affected by reduced abundance of its main prey, we analysed the encounter histories of 2999 Atlantic Puffins ringed on Machias Seal Island to estimate annual adult survival for the years 1999–2011 and assess trends in survival and the effects of several biological and environmental covariates. Features of Puffin biology and resighting procedures likely to introduce heterogeneity into our resighting probabilities were accounted for and models of survival were assessed using standard methods. We used the variance components procedure in Program MARK and survival estimates from a time-varying model to estimate the process variance (biological variation in survival) accounted for by suspected covariates of survival. Two proxies of food availability each explained more than half of the variation in annual survival: fishery landings of Atlantic Herring (52%) and per cent (by mass) of 1-group Herring in the diet of Puffin chicks (51%). In addition to these proxies, May sea-surface temperature accounted for 37% of variance in survival, but winter values of North Atlantic Oscillation showed no effect. Of those parameters of Puffin biology examined, chick growth rate explained 19% of the process variance in annual survival; laying date, fledging condition and fledging date all explained no variance. A decline in fishery landings of Herring since the early 1990s, and a concurrent decline in adult Puffin survival, reinforces concern for the health of the population of Herring, a keystone forage fish in this region, and of the community of marine predators in the Gulf of Maine that rely on Herring for their survival and reproduction.
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from Puffins to plankton a dna based analysis of a seabird food chain in the northern gulf of maine
PLOS ONE, 2013Co-Authors: Kirsten A. Bowser, Antony W Diamond, Jason A. AddisonAbstract:The predator-prey interactions within food chains are used to both characterize and understand ecosystems. Conventional methods of constructing food chains from visual identification of prey in predator diet can suffer from poor taxonomic resolution, misidentification, and bias against small or completely digestible prey. Next-generation sequencing (NGS) technology has become a powerful tool for diet reconstruction through barcoding of DNA in stomach content or fecal samples. Here we use multi-locus (16S and CO1) next-generation sequencing of DNA barcodes on the feces of Atlantic Puffin (Fratercula arctica) chicks (n=65) and adults (n=64) and the stomach contents of their main prey, Atlantic herring (Clupea harengus, n=44) to investigate a previously studied food chain. We compared conventional and molecular-derived chick diet, tested the similarity between the diets of Puffin adults and chicks, and determined whether herring prey can be detected in Puffin diet samples. There was high variability in the coverage of prey groups between 16S and CO1 markers. We identified more unique prey with our 16S compared to CO1 barcoding markers (51 and 39 taxa respectively) with only 12 taxa identified by both genes. We found no significant difference between the 16S-identified diets of Puffin adults (n=17) and chicks (n=41). Our molecular method is more taxonomically resolved and detected chick prey at higher frequencies than conventional field observations. Many likely planktonic prey of herring were detected in feces from Puffin adults and chicks, highlighting the impact secondary consumption may have on the interpretation of molecular dietary analysis. This study represents the first simultaneous molecular investigation into the diet of multiple components of a food chain and highlights the utility of a multi-locus approach to diet reconstruction that is broadly applicable to food web analysis.
Erikstad, Kjell E - One of the best experts on this subject based on the ideXlab platform.
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Centennial relationships between ocean temperature and Atlantic Puffin production reveal shifting decennial trends
'Wiley', 2021Co-Authors: Hansen, Erpur S., Anker-nilssen Tycho, Erikstad, Kjell E, Descamps Sébastien, Sandvik Hanno, Yoccoz Nigel, Bader Jürgen, Hodges Kevin, Mesquita, Michel D. S., Reiertsen, Tone KristinAbstract:The current warming of the oceans has been shown to have detrimental effects for a number of species. An understanding of the underlying mechanisms may be hampered by the non-linearity and non-stationarity of the relationships between temperature and demography, and by the insufficient length of available time series. Most demographic time series are too short to study the effects of climate on wildlife in the classical sense of meteorological patterns over at least 30 years. Here we present a harvest time series of Atlantic Puffins (Fratercula arctica) that goes back as far as 1880. It originates in the world's largest Puffin colony, in southwest Iceland, which has recently experienced a strong decline. By estimating an annual chick production index for 128 years, we found prolonged periods of strong correlations between local sea surface temperature (SST) and chick production. The sign of decennial correlations switches three times during this period, where the phases of strong negative correlations between Puffin productivity and SST correspond to the early 20th century Arctic warming period and to the most recent decades. Most of the variation (72%) in chick production is explained by a model in which productivity peaks at an SST of 7.1°C, clearly rejecting the assumption of a linear relationship. There is also evidence supporting non-stationarity: The SST at which Puffins production peaked has increased by 0.24°C during the 20th century, although the increase in average SST during the same period has been more than three times faster. The best supported models indicate that the population's decline is at least partially caused by the increasing SST around Iceland.publishedVersio
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Centennial relationships between ocean temperature and Atlantic Puffin production reveal shifting decennial trends
'Wiley', 2021Co-Authors: Hansen, Erpur S., Anker-nilssen Tycho, Erikstad, Kjell E, Descamps Sébastien, Sandvik Hanno, Yoccoz Nigel, Bader Jürgen, Hodges Kevin, Mesquita, Michel D. S., Reiertsen, Tone KristinAbstract:The current warming of the oceans has been shown to have detrimental effects for a number of species. An understanding of the underlying mechanisms may be hampered by the non-linearity and non-stationarity of the relationships between temperature and demography, and by the insufficient length of available time series. Most demographic time series are too short to study the effects of climate on wildlife in the classical sense of meteorological patterns over at least 30 years. Here we present a harvest time series of Atlantic Puffins (Fratercula arctica) that goes back as far as 1880. It originates in the world’s largest Puffin colony, in southwest Iceland, which has recently experienced a strong decline. By estimating an annual chick production index for 128 years, we found prolonged periods of strong correlations between local sea surface temperature (SST) and chick production. The sign of decennial correlations switches three times during this period, where the phases of strong negative correlations between Puffin productivity and SST correspond to the early 20th century Arctic warming period and to the most recent decades. Most of the variation (72%) in chick production is explained by a model in which productivity peaks at an SST of 7.1 °C, clearly rejecting the assumption of a linear relationship. There is also evidence supporting non-stationarity: the SST at which Puffins production peaked has increased by 0.24 °C during the 20th century, although the increase in average SST during the same period has been more than three times faster. The best supported models indicate that the population’s decline is at least partially caused by the increasing SST around Iceland
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Sympatric Atlantic Puffins and razorbills show contrasting responses to adverse marine conditions during winter foraging within the North Sea
BMC, 2019Co-Authors: St. John Glew Katie, Erikstad, Kjell E, Harris, Michael P., Wanless Sarah, Daunt Francis, Strøm Hallvard, Speakman, John R., Kürten Benjamin, Trueman, Clive N.Abstract:Background: Natural environments are dynamic systems with conditions varying across years. Higher trophic level consumers may respond to changes in the distribution and quality of available prey by moving to locate new resources or by switching diets. In order to persist, sympatric species with similar ecological niches may show contrasting foraging responses to changes in environmental conditions. However, in marine environments this assertion remains largely untested for highly mobile predators outside the breeding season because of the challenges of quantifying foraging location and trophic position under contrasting conditions. Method: Differences in overwinter survival rates of two populations of North Sea seabirds (Atlantic Puffins (Fratercula arctica) and razorbills (Alca torda)) indicated that environmental conditions differed between 2007/08 (low survival and thus poor conditions) and 2014/15 (higher survival, favourable conditions). We used a combination of bird-borne data loggers and stable isotope analyses to test 1) whether these sympatric species showed consistent responses with respect to foraging location and trophic position to these contrasting winter conditions during periods when body and cheek feathers were being grown (moult) and 2) whether any observed changes in moult locations and diet could be related to the abundance and distribution of potential prey species of differing energetic quality. Results: Puffins and razorbills showed divergent foraging responses to contrasting winter conditions. Puffins foraging in the North Sea used broadly similar foraging locations during moult in both winters. However, Puffin diet significantly differed, with a lower average trophic position in the winter characterised by lower survival rates. By contrast, razorbills’ trophic position increased in the poor survival winter and the population foraged in more distant southerly waters of the North Sea. Conclusions: Populations of North Sea Puffins and razorbills showed contrasting foraging responses when environmental conditions, as indicated by overwinter survival differed. Conservation of mobile predators, many of which are in sharp decline, may benefit from dynamic spatial based management approaches focusing on behavioural changes in response to changing environmental conditions, particularly during life history stages associated with increased mortality. Fratercula arctica, Isoscape, Alca torda, Marine spatial management, North Sea, Seabird foraging behaviour, Spatial ecology, Trophic ecology, Moul
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Moult location and diet of auks in the North Sea inferred from coupled light-based and isotope-based geolocation
Inter Research, 2018Co-Authors: Glew, Katie St. John, Erikstad, Kjell E, Harris, Michael P., Wanless Sarah, Daunt Francis, Strøm Hallvard, Trueman, Clive N.Abstract:Many pelagic seabirds moult their feathers while at sea, which is an energetically costly behaviour. Mortality rates during moult can be high, so spatial and trophic ecology during this critical period is important for understanding demographic patterns. Unfortunately, individual foraging behaviours specifically linked to at-sea moulting are commonly unclear. This paper combines 2 different approaches to geolocation: data from bird-borne geolocation loggers and stableisotope assignment using carbon and nitrogen isotope maps (isoscapes). Coupling 2 geolocation processes allows some uncertainties associated with isotope-based assignment to be constrained. We applied this approach to quantify species-specific foraging locations and individual trophic variability during feather regrowth in 3 sympatric auk populations breeding on the Isle of May, Scotland (common guillemot Uria aalge, razorbill Alca torda and Atlantic Puffin Fratercula arctica). Inferred foraging areas during moult differed between species and feather types. Guillemots likely underwent moult within the southern North Sea, razorbills along the east coast of England and into the southern North Sea and Puffins off the east coast of Scotland. Estimates of individual trophic position varied considerably within feather types (up to 1 trophic level difference between individuals), among feather types grown during different time periods and across the 3 species, with guillemots consistently foraging at higher trophic positions than razorbills and Puffins. Used in combination, these methods better constrain foraging areas during moulting, and provide a technique to explore individual differences and flexibility in foraging strategy, which is valuable information for both seabird conservation and marine spatial planning. Isoscape · Trophic ecology · Foraging · Moult · Atlantic Puffin · Common guillemot · Razorbil
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Moult location and diet of auks in the North Sea inferred from coupled light-based and isotope-based geolocation
'Inter-Research Science Center', 2018Co-Authors: Glew, Katie St. John, Erikstad, Kjell E, Harris, Michael P., Wanless Sarah, Daunt Francis, Strøm Hallvard, Trueman, Clive N.Abstract:Many pelagic seabirds moult their feathers while at sea, which is an energetically costly behaviour. Mortality rates during moult can be high, so spatial and trophic ecology during this critical period is important for understanding demographic patterns. Unfortunately, individual foraging behaviours specifically linked to at-sea moulting are commonly unclear. This paper combines 2 different approaches to geolocation: data from bird-borne geolocation loggers and stableisotope assignment using carbon and nitrogen isotope maps (isoscapes). Coupling 2 geolocation processes allows some uncertainties associated with isotope-based assignment to be constrained. We applied this approach to quantify species-specific foraging locations and individual trophic variability during feather regrowth in 3 sympatric auk populations breeding on the Isle of May, Scotland (common guillemot Uria aalge, razorbill Alca torda and Atlantic Puffin Fratercula arctica). Inferred foraging areas during moult differed between species and feather types. Guillemots likely underwent moult within the southern North Sea, razorbills along the east coast of England and into the southern North Sea and Puffins off the east coast of Scotland. Estimates of individual trophic position varied considerably within feather types (up to 1 trophic level difference between individuals), among feather types grown during different time periods and across the 3 species, with guillemots consistently foraging at higher trophic positions than razorbills and Puffins. Used in combination, these methods better constrain foraging areas during moulting, and provide a technique to explore individual differences and flexibility in foraging strategy, which is valuable information for both seabird conservation and marine spatial planning.publishedVersio
