Native Shrimp Research Articles

Temperature and diet effect on the pepsin enzyme activities, digestive somatic index and relative gut length of Malabar blood snapper (Lutjanus malabaricus Bloch & Schneider, 1801)

An integrated experiment was performed on juvenile Malabar blood snapper (Lutjanus malabaricus) to investigate the effect of temperature and diet in their pepsin activities in relation with digestive somatic index (IDS) and relative gut length (RGL). One hundred twenty L. malabaricus juvenile (13–15cm) were equally distributed among four exposed temperature treatments (22, 26, 30 and 34°C) representing their seasonal range and to account for end of century predicted temperatures, and two diets as commercial pellet and natural shrimp. After 7days of acclimation period fish were reared for 30days in twenty four 400l glass aquaria at a stocking density of 5 fish tank−1. All treatments were three replications. The result showed that, IDS and RGL gradually decreased with increasing temperature up to 30°C and again increase at 34°C. And the values were also higher in pellet feeding fish than shrimp feeding fish at all the temperatures. Alternatively, in pepsin activity, an increased activity was seen between 26°C to 30°C and this activity was significantly higher than the 22°C and 34°C (P<0.05). In general, highest pepsin activity was observed among fish which fed on a natural shrimp diet reared at temperature 30°C (5.47±1.60Umgprotein−1), followed by those at 26, 34 and 22°C (P<0.05) at both diet however, no mortalities were observed. These results could be used as a basis for selecting a suitable diet for maximizing the growth and sustainable aquaculture coping with global warming.

宮城県に侵入した淡水エビ:カワリヌマエビ属Neocaridina spp.の分布拡大とヌカエビParatya compressa improvisaへの影響

宮城県に侵入した淡水エビ:カワリヌマエビ属Neocaridina spp.の分布拡大とヌカエビParatya compressa improvisaへの影響

Development of water-soluble chitosan powder and its antimicrobial effect against inoculated Listeria innocua NRRL B-33016 on shrimp

The objectives of this study were to produce water-soluble chitosan (WSC) powder and to evaluate the effect of WSC on the survival of Listeria innocua inoculated onto shrimp surfaces. WSC powder was produced using a combination of enzymatic hydrolysis, ultrafiltration, and freeze drying. WSC solutions of 0.5, 1, 3, and 5 g/100 mL concentrations were prepared by dissolving the WSC powder in water. All concentrations of the WSC solutions showed anti-L. innocua activity in vitro, with the 5 g/100 mL WSC solution reducing initial L. innocua counts by 7.43 log CFU/mL. Freshly acquired shrimp were inoculated with L. innocua to an initial concentration of 7.65 log CFU/g. The inoculated shrimp samples were separately dipped in water (control) and in the WSC solutions for 1 min. After dipping in deionized water and 0.5, 1, 3, and 5 g/100 mL WSC solutions, the L. innocua counts were reduced by 1.50, 1.99, 2.25, 3.56, and 5.34 log CFU/g, respectively. For aerobic bacteria loads (8.43 log CFU/g) including L. innocua and natural shrimp microflora, dipping in deionized water and 0.5, 1, 3, and 5 g/100 mL WSC solution resulted in 0, 0.69, 3.21, 3.71, and 4.43 log CFU/g reductions, respectively. This study demonstrated that a low viscosity (0.01–0.29 Pa s) WSC solution could be used as an antimicrobial agent to reduce microbial loads on the surface of shrimp.

Habitat and indigenous gut microbes contribute to the plasticity of gut microbiome in oriental river prawn during rapid environmental change.

Growing evidence points out that the capacity of organisms to acclimate or adapt to new habitat conditions basically depends on their phenomic plasticity attributes, of which their gut commensal microbiota might be an essential impact factor. Especially in aquatic organisms, which are in direct and continual contact with the aquatic environment, the complex and dynamic microbiota have significant effects on health and development. However, an understanding of the relative contribution of internal sorting (host genetic) and colonization (environmental) processes is still unclear. To understand how microbial communities differ in response to rapid environmental change, we surveyed and studied the environmental and gut microbiota of native and habitat-exchanged shrimp (Macrobrachium nipponense) using 16S rRNA amplicon sequencing on the Illumina MiSeq platform. Corresponding with microbial diversity of their living water areas, the divergence in gut microbes of lake-to-river shrimp (CK) increased, while that of river-to-lake shrimp (KC) decreased. Importantly, among the candidate environment specific gut microbes in habitat-exchanged shrimp, over half of reads were associated with the indigenous bacteria in native shrimp gut, yet more candidates presented in CK may reflect the complexity of new environment. Our results suggest that shrimp gut microbiota has high plasticity when its host faces environmental changes, even over short timescales. Further, the changes in external environment might influence the gut microbiome not just by providing environment-associated microbes directly, but also by interfering with the composition of indigenous gut bacteria indirectly.

Ecological niche differentiation between native and non-native shrimps in the northern Baltic Sea

Invasions of non-native species are modifying global biodiversity but the ecological mechanisms underlying invasion processes are still not well understood. A degree of niche separation of non-native and sympatric native species can possibly explain the success of novel species in their new environment. In this study, we quantified experimentally and in situ the environmental niche space of caridean shrimps (native Crangon crangon and Palaemon adspersus, non-native Palaemon elegans) inhabiting the northern Baltic Sea. Field studies showed that the non-native P. elegans had wider geographical range compared to native species although the level of habitat specialization was similar in both Palaemon species. There were clear differences in shrimp habitat occupancy with P. elegans inhabiting lower salinity areas and more eutrophicated habitats compared to the native species. Consequently, the non-native shrimp has occupied large areas of the northern Baltic Sea that were previously devoid of the native shrimps. Experiments demonstrated that the non-native shrimp had higher affinity to vegetated substrates compared to native species. The study suggests that the abilities of the non-native shrimp to thrive in more stressful habitats (lower salinity, higher eutrophication), that are sub-optimal for native shrimps, plausibly explain the invasion success of P. elegans.

The trophic position of the alien crab Rhithropanopeus harrisii (crustacea decapoda panopeidae) in the Taman Bay, Sea of Azov community

This work concerns the trophic web positioning of the alien crab Rhithropanopeus harrisii and other common marine invertebrate species and fishes in the benthic ecosystem of the shallows of Taman Bay, Sea of Azov. The base of the trophic web in this system is composed of phytoplankton, macrophytes (algae and marine grasses), and reeds that use atmospheric carbon for photosynthesis. Analysis of the isotopic composition of nitrogen and carbon has shown that although marine grasses are dominating primary producers in the shallows of the bay, primary consumers (such as Cerastoderma glaucum, Porifera gen. sp., Gammarus aequicauda, Deshayesorchestia deshayesii and Idotea balthica) only partially use this organic source; instead, they use a combination of different sources of primary production. It has been shown that the food source of the alien crab is primarily of animal origin. In Taman Bay, R. harrisii is on the same trophic level as other carnivores/scavengers: benthic fishes Syngnathus nigrolineatus, Gobius spp. and native crab Pilumnus hirtellus and shrimp Palaemon adspersus.

Presence of Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV) in Native Shrimps from Southern Mexico

A survey for Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV) was performed during two catching seasons of native shrimps in the Yucatan Coast in the Gulf of Mexico. The mtDNA COI barcode identified two endemic species; the southern pink shrimp Penaeus notialis (Pérez Fantante, 1967) and the northern pink shrimp Penaeus brasiliensis (Latreille, 1987) (previously described as Farfantepenaeus brasiliensis). The prevalence of IHHNV was of 18.18% in 2016, and of 8.57% in 2017. All organisms tested negative for WSSV. This is the first identification of wild shrimps in the state of Yucatan Mexico by mtDNA COI barcode as well as the first identification of IHHNV in such species. The presence of IHHNV in wild shrimps populations has a potential of persisting in the coast of Yucatan with putative detrimental effect on local fisheries because once established in natural waters and hosts; such pathogens are almost impossible to eradicate.

Distribution of introduced freshwater shrimp Neocaridina sp. and native shrimp Paratya improvisa in the Tsurimi River in eastern Japan.

Distribution of introduced freshwater shrimp <i>Neocaridina</i> sp. and native shrimp <i>Paratya improvisa</i> in the Tsurimi River in eastern Japan.

Domestic and imports sources of supply to the US shrimp market and anti-dumping duties

Purpose The purpose of this paper is to provide an economic analysis of the sources of supply to the US shrimp market. Design/methodology/approach The paper uses monthly time series data to estimate a simultaneous equations model with equations for domestic supplies from the Gulf of Mexico, imports, and prices. Findings Estimated long-run elasticities suggest that the domestic shrimp supply appears to be explained by seasons, diesel fuel price, hurricane activity, and shrimp price. The authors find evidence of a downward-slopping supply curve for the domestic harvesters that is likely to be temporary. Furthermore, anti-dumping duties have been ineffectual in curtailing imports produced by exploitation of natural shrimp biomass in developing countries and by technological advancements in aquaculture production. The authors also find evidence of a low exchange rate pass through. Finally, while domestic and import prices are not cointegrated, there is a two-way causality between them. Practical implications The authors found evidence that shrimp prices have fallen as import supply, due to technological advances in aquaculture, has risen faster than the US domestic demand over time suggesting a downward sloping supply curve. Also, the falling value of the US dollar has discouraged the imports, while the anti-dumping duties appear to have had little influence on the aggregate level of imports. Originality/value It provides a thorough investigation of the supply side of an important component of the US seafood market displaying the complexity of domestic producers’ reaction to falling prices, and ineffectual protectionism.

Effects of temperature and diet on length-weight relationship and condition factor of the juvenile Malabar blood snapper (Lutjanus malabaricus Bloch & Schneider, 1801).

In this study we aimed to analyze the effects of water temperature and diet on the length-weight relationship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The experiment was conducted in the laboratory using a flow-through-sea-water system. The fish were subjected to four different temperatures (22, 26, 30, and 34 °C) and two diets (commercial pellet and natural shrimp). Fish were fed twice daily. L. malabaricus exhibited negative allometric growth (b<3) at the beginning of the experiment (Day 0) at all temperatures and both diets except for 22 °C fed with shrimp, which showed isometric growth (b=3). Conversely, at the end of the experiment (Day 30) fish showed isometric growth (b=3) at 30 °C fed with the pellet diet, indicating that the shape of the fish did not change with increasing weight and length, and a positive allometric growth (b>3) at 30 °C fed with shrimp diet, which indicated that fish weight increases faster than their length. The rest of the temperatures represented negative allometric growth (b<3) on both diet, meaning that fish became lighter with increasing size. The condition factors in the initial and final measurements were greater than 1, indicating the state of health of the fish, except for those fed on a pellet diet at 34 °C. However, the best condition was obtained at 30 °C on both diets. Nevertheless, diets did not have a significant effect on growth and condition of juvenile L. malabaricus. The data obtained from this study suggested culturing L. malabaricus at 30 °C and feeding on the pellet or shrimp diet, which will optimize the overall production and condition of this commercially important fish species.

Assessing the status of an artisanal shrimp fishery in a Ramsar wetland in Jamaica: The effects of seasonality, extreme La Niña episodes and elevated temperature on landings

An invasive crayfish, Cherax quadricarinatus, and several native shrimp species (Macrobrachium acanthurus, Macrobrachium faustinum, Macrobrachium carcinus, Xiphocaris elongata, and Atyidae sp.) found in the Black River Lower Morass (BRLM), a Ramsar Wetland in Jamaica, support subsistence and artisanal fisheries. Management of this fishery requires information on factors that influence their abundance. Consequently, we assessed the effects of seasonality, extreme and double La Niña episodes (in 2011) and elevated atmospheric temperature (in 2011 and 2012) on weekly Decapoda landing data, collected over a period of two years (2010–2012). The catch of native species showed a cyclical trend every 6 months, coinciding with the dry and wet seasons. The invasive crayfish landing showed a reverse trend during the first year, after which no pattern could be discerned. A dynamic factor analysis (DFA) model with two common trends and four explanatory variables (conductivity, mean weekly number of traps hauled, weekly mean water level, and mean dissolved oxygen) was the optimal model to characterize the variation in wet-weight landings. A generalized additive mixed model with an auto-regressive moving average (ARMA) error structure was used to show that the extreme and double La Niñas were associated with lower monthly atmospheric temperature. Sea surface temperature anomaly in region 3 (a proxy to ENSO) and the trend in temperature were then used to predict the wet weight of native shrimp (U-shaped relationship) and the invasive crayfish (reverse-j shaped relationship), respectively. The native shrimp (mean sustainable yield, MSY = 3469 kg and mean catch per fisher = 2.67 kg) and invasive crayfish (MSY = 11 kg and mean catch per fisher = 0.67 kg) are under fished, although populations of the native shrimp are possibly declining, whereas that of the invasive crayfish may be growing. The declining trend may have adverse implications for the stock of the native shrimp species, which has a higher economic value, if fishing pressure is not reduced/restricted or increased on the invasive crayfish, especially during seasonal and/or ENSO related declines in native shrimp stocks.

Laboratory assessment of feeding-behavior interactions between the introduced Pacific white shrimp Litopenaeus vannamei (Boone, 1931) (Penaeidae) and five native shrimps plus a crab species in Thailand

The Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is native to the Pacific coast of Central and South America. This species was first introduced to Thailand in 1998 for aquaculture and as a replacement for Penaeus monodon Fabicius, 1798 because of problems with disease outbreaks and poor growth performance of the latter. Escapes of cultured L. vannamei to the wild were detected recently; however, little is known about the effects of the escape of cultured shrimps on the local ecosystems. In this laboratory study, the feeding behavior of L. vannamei was examined and compared with that of five native shrimps and a native crab species to determine the behavioral interactions and potential for food competition. With regards to palatability of the five native shrimp species, L. vannamei was non-selective, consuming the first piece of meat encountered. When all species were tested separately, Litopenaeus vannamei consumed its food faster than the native shrimps. In paired one-onone contests, L. vannamei was much more aggressive in competing for food than the native shrimp species. When paired with the native crab species, Charybdis affinis, L. vannamei lost 100% of the contests and the crab sometimes killed and ate the shrimp. Due to its behavioural dominance in feeding contests with native shrimps, L. vannamei pose a serious threat to native shrimp species should it become fully established in marine waters of Thailand.

Comparing cestode infections and their consequences for host fitness in two sexual branchiopods: alien Artemia franciscana and native A. salina from syntopic-populations.

The American brine shrimp Artemia franciscana is invasive in the Mediterranean region where it has displaced native species (the sexual A. salina, and the clonal A. parthenogenetica) from many salt pond complexes. Artemia populations are parasitized by numerous avian cestodes whose effects have been studied in native species. We present a study from the Ebro Delta salterns (NE Spain), in a salt pond where both A. franciscana and native A. salina populations coexist, providing a unique opportunity to compare the parasite loads of the two sexual species in syntopy. The native species had consistently higher infection parameters, largely because the dominant cestode in A. salina adults and juveniles (Flamingolepis liguloides) was much rarer in A. franciscana. The most abundant cestodes in the alien species were Eurycestus avoceti (in adults) and Flamingolepis flamingo (in juveniles). The abundance of E. avoceti and F. liguloides was higher in the A. franciscana population syntopic with A. salina than in a population sampled at the same time in another pond where the native brine shrimp was absent, possibly because the native shrimp provides a better reservoir for parasite circulation. Infection by cestodes caused red colouration in adult and juvenile A. salina, and also led to castration in a high proportion of adult females. Both these effects were significantly stronger in the native host than in A. franciscana with the same parasite loads. However, for the first time, significant castration effects (for E. avoceti and F. liguloides) and colour change (for six cestode species) were observed in infected A. franciscana. Avian cestodes are likely to help A. franciscana outcompete native species. At the same time, they are likely to reduce the production of A. franciscana cysts in areas where they are harvested commercially.

Detection of White Spot Syndrome Virus in Cultured Penaeid Shrimp using Histopathological Observation and Polymerase Chain Reaction

White spot syndrome virus (WSSV) in Egyptian shrimp is poorly understood and there is no available information regarding possible WSSV infection of native shrimp in Egypt. Therefore, the main goal of this work was to diagnose WSSV in Egyptian shrimp by histopathological examination and molecular based methods (PCR). A total of 90 shrimp samples showed circular white patches in the cuticle were collected from the local fish markets of high shrimp producing region in three provinces of Egypt. The three regions located at the south coast of Mediterranean Sea, including El-Arish, Dumiatta and Kafr El-sheikh. Histopathological examination of different organs showed intranuclear basophilic inclusion bodies. Single-step PCR results with primers specific for the gene encoding VP28 gave a predicted amplified product at 677 bp. The primer pair designed from WSSV genomic sequence yields a 677 bp fragment by agarose gel electrophoresis.

The Baltic prawn Palaemon adspersus Rathke, 1837 (Decapoda, Caridea, Palaemonidae): first record, possible establishment, and illustrated key of the subfamily Palaemoninae in northwest Atlantic waters

This study documents the introduction of the European Baltic prawn, Palaemon adspersus Rathke, 1837 to the coastal waters of northeastern North America, specifically the west coast of Newfoundland and the Magdalen Islands in the Gulf of St. Lawrence, Canada. Species identification was verified using morphological and genetic criteria. In September 2011, the first specimens of P. adspersus were collected in Gulf of St. Lawrence waters near Stephenville Crossing, Newfoundland, Canada. In 2012, additional P. adspersus specimens were collected in this area and at St. Andrew’s, located further south in western Newfoundland and in 2013 several egg-bearing females were collected further north in York Harbour. Accidental transport by ballast water of ships seems the likely vector for transport of Baltic prawn to the Gulf of St. Lawrence from Northern Europe or the Caspian Sea. It is possible that this shrimp has a wider presence in Atlantic Canadian waters but, due to its close resemblance to native shrimp species, it may have been previously misidentified, as occurred with specimens collected from the Magdalen Islands. We further expect that other species of the genus Palaemon, including P. elegans Rathke, 1837 from the Baltic Sea or northeastern United States, and P. macrodactylus Rathbun, 1902 from the northeastern United States, may invade the Gulf of St. Lawrence. We provide an illustrated key for the identification of these exotic Palaemon species and to differentiate them from native members of the subfamily Palaemoninae.

Australian red claw crayfish (Cherax quadricarinatus) is susceptible to yellow head virus (YHV) infection and can transmit it to the black tiger shrimp (Penaeus monodon)

Abstract The Australian red claw crayfish (RCC), Cherax quadricarinatus was introduced in Thailand more than two decades ago for culture in freshwater areas where marine penaeid shrimp are also frequently farmed. Despite many reports of various diseases that occur in RCC in Australia (both from natural habitats and from farms), there have been no reports of its diseases when farmed in Thailand. Our recent study on RCC cultured in Thailand revealed that it is susceptible to WSSV infection and that it can transmit the virus to native shrimp species such as the black tiger shrimp ( Penaeus monodon ). Thus, we decided to continue by testing whether RCC were also susceptible to endemic yellow head virus (YHV) and also capable of transmitting it to black tiger shrimp (BTS). Using three different exposure methods (injection, feeding and cohabitation) with test RCC, we obtained no YHV pathology or positive immunoreactions using monoclonal antibodies against all 3 structural proteins of YHV. By contrast, a standard RT-PCR assay targeting the RdRp gene of YHV with RNA extracted from the experimentally exposed red claw did give positive results. In addition, BTS that tested negative for YHV and were then cohabitated (separated by a plastic net) with RT-PCR positive RCC became infected with YHV and died, exhibiting the severe histopathology typical of yellow head disease. This was confirmed by strong positive immunohistochemical reactions for YHV and positive RT-PCR results. These results suggested that the experimentally exposed RCC were susceptible to YHV infection at sufficient level to allow transmission to BTS but not sufficient to allow detection by the standard histological methods currently used. Statement of relevance The loss due to the yellow head virus is second only to that of white spot syndrome virus (WSSV) in South East Asia. Despite the continual search for its reservoir, since its discovery in the early 1990s, the reservoir for YHV-1 (the most virulent strain of YHV found in Thailand) has still not been identified. Outbreaks of the virus in cultivated, exotic whiteleg shrimp P. vannamei that originate from SPF stocks known to be free of the virus, suggesting that the outbreaks occur via horizontal transmission from an environmental source. Based on our results, exotic red claw crayfish ( Cherax quadricarinatus ) that are cultured in fresh water areas where marine penaeid shrimp are also frequently farmed should be added to the list of potential reservoirs. Red claw crayfish, from our results, is susceptible but highly tolerant to the virus. Infected red claw crayfish could transmit the virus without showing any signs of yellow head disease. These facts make them perfect carrier for the virus. YHV infection in red claw crayfish could be detected by RT-PCR only not by routine histology or immunohistochemistry.

Alien invasions and livelihoods: Economic benefits of invasive Australian Red Claw crayfish in Jamaica

Invasive species have caused widespread economic and environmental disruption, which have been widely studied. However, their potential benefits have received much less attention. If invasive species contribute to livelihoods, their eradication may negatively impact wellbeing. Failing to value these benefits may lead to an undervaluation of invaded ecosystems. We assess the potential economic benefits of an invasive species within an artisanal fishery in Jamaica. We monitored catches over 259 fisherman-days, and conducted 45 semi-structured interviews, with 76 fishermen. We show that the invasive Australian Red Claw crayfish (Cherax quadricarinatus) is an important source of income for fishermen within the Black River Lower Morass of Jamaica and supplement incomes during periods when native shrimp (Macrobrachium spp.) catches decline. We also show that full-time fishermen and those who have no alternative occupations expend the greatest fishing effort. We use the intra-annual variation of fishermen's harvest effort between seasons (when catch per unit effort changes) as a proxy for dependence. Using this measure, we found that the least wealthy appear to be the most dependent on fishing, and consequently benefit the most from the invasive crayfish. Our results demonstrate the importance of considering the potential benefits of invasive species within integrated landscape management.

MTs in Palaemonetes argentinus as potential biomarkers of zinc contamination in freshwaters

Aquatic invertebrates take up and accumulate essential and non-essential trace metals even when both are likely to be poisonous. In order to study the potential of the metallothioneins (MTs) as biomarkers of metal contamination in native shrimp Palaemonetes argentinus, organisms have been exposed at 0, 5, 50 and 500μgL−1 of zinc for 96h. Moreover, accumulation and subcellular distribution of this essential metal were evaluated. A significant Zn accumulation was observed in different body sections. Higher Zn levels occurred in cephalothorax compared to abdomen, especially at the highest exposure concentration (500μg ZnL−1). A clear differential subcellular metal distribution between cephalothorax and abdomen was also observed. In cephalothorax Zn was similarly distributed between the soluble and insoluble fractions; while in abdomen, when total Zn increased, insoluble metal augmented more markedly than the soluble one. Cytosolic Zn levels increased more in cephalothorax than in abdomen of shrimps exposed to 500μg ZnL−1 when compared to control. Finally, a significant induction of MTs was observed in cephalothorax at 500μg ZnL−1. A potential role for MTs as biomarkers in P. argentinus should be further studied to enhance the sensitivity of the response, although it is likely that MTs play a key role in metal detoxification since the increase of these proteins is linked to metal challenge.

Flow regime in a restored wetland determines trophic links and species composition in the aquatic macroinvertebrate community

In a restored wetland (South of Spain), where different flow regimes control water exchange with the adjacent Guadalquivir estuary, the native Palaemon varians coexists with an exotic counterpart species Palaemon macrodactylus. This controlled m\\acrocosm offers an excellent opportunity to investigate how the effects of water management, through different flow regimes, and the presence of a non-native species affect the aquatic community and the trophic niche (by gut contents and C-N isotopic composition) of the native shrimp Palaemon varians. We found that increased water exchange rate (5% day−1 in mixed ponds vs. 0.1% day−1 in extensive ponds) modified the aquatic community of this wetland; while extensive ponds are dominated by isopods and amphipods with low presence of P. macrodactylus, mixed ponds presented high biomass of mysids, corixids, copepods and both shrimp species. An estuarine origin of nutrients and primary production might explain seasonal and spatial differences found among ponds of this wetland. A combined analysis of gut contents and isotopic composition of the native and the exotic species showed that: (1) native P. varians is mainly omnivorous (2) while the non-native P. macrodactylus is more zooplanktivorous and (3) a dietary overlap occurred when both species coexist at mixed ponds where a higher water exchange and high abundance of mysids and copepods diversifies the native species' diet. Thus differences in the trophic ecology of both species are clearly explained by water management. This experimental study is a valuable tool for integrated management between river basin and wetlands since it allows quantification of wetland community changes in response to the flow regime.

Emulsifying and Antioxidant Properties of a Shrimp (Pandalus borealis) Hydrolysate Conjugated With Xylose or Dextran Through the Maillard Reaction by Dry-Heating in Mild Conditions

&lt;p&gt;Maillard Reaction (MR) was performed in ‘dry’ conditions at 50 °C for 48 h between native shrimp hydrolysate (HN) and xylose or dextran. Resulting emulsifying and antioxidant properties were assessed. HN was compared with a native sodium caseinate (CN) and its glycoconjugates, obtained in the same conditions. Compared to dextran, xylose resulted in significant browning after MR with HN or CN, but HN-xylose conjugates showed the most functional modifications. Increasing xylose/HN ratios led to significant molecular rearrangements in the peptide populations and intermediate aromatic compounds of the MR detected at 220 and 294 nm, respectively. Consequently, HN-xylose conjugates had higher reducing power than HN. Conversely, at 0.5% (w/w), a sharp increase in consistency index and apparent viscosity of emulsions after a 4-h ageing period was obtained with the lowest xylose/HN ratio. These results confirm that MR is a promising process for the production of new natural food ingredients from marine-derived protein sources.&lt;/p&gt;