In vitro intestinal digestion of lipids from the marine diatom Porosira glacialis compared to commercial LC n-3 PUFA products

Marine sources of long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) are in high demand for use in health supplements. Mass cultivated marine microalgae is a promising and sustainable source of LC n-3 PUFA, which relieves pressure on natural fish stocks. The lipid class profile from cultivated photosynthetic algae differ from the marine organisms currently used for the production of LC n-3 PUFA. The objective of this study was to compare in vitro intestinal digestion of oil extracted from the cold-adapted marine diatom Porosira glacialis with commercially available LC n-3 PUFA supplements; cod liver oil, krill oil, ethyl ester concentrate, and oil from the copepod Calanus finmarchicus (Calanus® oil). The changes in the free fatty acids and neutral and polar lipids during the enzymatic hydrolysis were characterized by liquid and gas chromatography. In Calanus® oil and the Ethyl ester concentrate, the free fatty acids increased very little (4.0 and 4.6%, respectively) during digestion. In comparison, free fatty acids in Krill oil and P. glacialis oil increased by 14.7 and 17.0%, respectively. Cod liver oil had the highest increase (28.2%) in free fatty acids during the digestion. Monounsaturated and saturated fatty acids were more easily released than polyunsaturated fatty acids in all five oils

Determination of pH in pre rigor fish muscle - method matters

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Aquatic Food Product Technology on 06.04.2020, available at: https://doi.org/10.1080/10498850.2020.1748781.The determination of post mortem muscle pH are often carried out in studies on how pre-slaughter handling influences the development of rigor mortis and the quality of the fish products. The analysis might be performed by inserting a pH-electrode into the intact flesh or using a suspension containing a minced muscle sample. Although it has been known for a long time that mincing muscle tissue accelerates glycolysis and breakdown of adenosine triphosphate (ATP), more recent studies quite commonly determine pH after mincing pre rigor muscle without including an enzyme inhibitor that arrests glycolysis. This may have resulted in anomalously low pre rigor muscle pH. The aim of the present work was to compare the two methods of pH determination in pre rigor fish muscle and to highlight the importance of including the enzyme inhibitor when homogenizing pre rigor fish muscle prior to pH analysis

Obesity-induced alterations in the gut microbiome in female mice fed a high-fat diet are antagonized by dietary supplementation with a novel, wax ester–rich, marine oil

Dietary supplementation with calanus oil, a novel wax ester–rich marine oil, has been shown to reduce adiposity in high-fat diet (HFD)–induced obese mice. Current evidence suggests that obesity and its comorbidities are intrinsically linked with unfavorable changes in the intestinal microbiome. Thus, in line with its antiobesity effect, we hypothesized that dietary supplementation with calanus oil should counteract the obesity-related deleterious changes in the gut microbiota. Seven-week-old female C57bl/6J mice received an HFD for 12 weeks to induce obesity followed by 8-week supplementation with 2% calanus oil. For comparative reasons, another group of mice was treated with exenatide, an antiobesogenic glucagon-like peptide-1 receptor agonist. Mice fed normal chow diet or nonsupplemented HFD for 20 weeks served as lean and obese controls, respectively. 16S rRNA gene sequencing was performed on fecal samples from the colon. HFD increased the abundance of the Lactococcus and Leuconostoc genera relative to normal chow diet, whereas abundances of Allobaculum and Oscillospira were decreased. Supplementation with calanus oil led to an apparent overrepresentation of Lactobacillus and Streptococcus and underrepresentation of Bilophila. Exenatide prevented the HFD-induced increase in Lactococcus and caused a decrease in the abundance of Streptococcus compared to the HFD group. Thus, HFD altered the gut microbiota composition in an unhealthy direction by increasing the abundance of proinflammatory genera while reducing those considered health-promoting. These obesity-induced changes were antagonized by both calanus oil and exenatide

Fish silage hydrolysates: Not only a feed nutrient, but also a useful feed additive

Background: Processing of fish and shellfish may result in substantial amounts of by-products and unless they can be used as food, the most realistic option in most cases is the production of preserved feed nutrients. If large volumes are available, reduction to fishmeal and fish oil is the preferred technology. However, fresh by-products are most often available in insufficient quantities to justify production of fishmeal. Preservation by acid silage is, however, a simple and inexpensive alternative. Scope and approach: The purpose of this paper is to highlight that silage preservation of by-products using formic acid produces a protein hydrolysate that may function as a useful feed additive and not only an important feed nutrient. The fast growing global aquaculture industry is particularly in need of high quality feed nutrients and the focus in this paper is therefore on including acid protein hydrolysate in diets for fish and shellfish. Key findings and conclusions: The proteins in acid silage are largely hydrolysed to free amino acids and short-chain peptides. Studies have shown that moderate amounts of protein hydrolysate may successfully be included in fish feed and in some cases this leads to improved performance. In addition, the formic acid in the hydrolysate may contribute to the growth and well-being of fish, in particular under unfavourable microbiological conditions. This may encourage fish processors to preserve by-products using acid silage and feed producers to incorporate the products in the feed

Gender-specific responses of mature Atlantic cod (Gadus morhua L.) to feed deprivation

publishedVersionacceptedVersio

Effects of Long-Term Feed Deprivation on the Development of Rigor Mortis and Aspects of Muscle Quality in Live-Stored Mature Atlantic Cod (Gadus Morhua L.)

acceptedVersio

Rapport/Report 13/2009 English summary

I dette forsøket ble torsk fanget levende og lagret i merd hvor den ble fôret med hhv. lodde og kommersielt torskefôr i 3 måneder. Etter skånsom slakting og utblødning i 30 minutter, ble fisken sløyd og de biologiske data registrert før maskinell filetering enten pre-rigor (innen 2 timer etter død) og post-rigor (etter 4 dagers is-lagring av sløyd fisk). Det ble produsert ryggfileter (Loins) enten med eller uten skinn. Vekt og lengde på ryggfiletene ble registrert ved filetering og på dag 4, 9 og 14 for de pre-rigor produserte filetene, mens de samme målingene ble gjort på dag 9 og 14 for de post-rigor produserte filetene. Resultatene viser at pre-rigor produserte loins med skinn taper mindre vann og krymper mindre. Det var ingen signifikant forskjell i muskel pH og vanninnhold mellom de ulike gruppene. Vannbindingsevnen var signifikant lavere i pre-rigor produserte loins. Fisken som hadde fått tørrfôr hadde signifikant lysere muskel uavhengig av fileteringstidspunktet. Profesjonelle kokker vurderte kvaliteten av loins fra både den tørrfôrede og den loddeforede torsken som meget god.Torsk fra merd: Pre-rigor produksjon av loins med skinnRapport/Report 13/2009 English summarypublishedVersio

Torsk fra merd: Pre-rigor produksjon av loins med skinn

Source at https://nofima.no/en/pub/1174033/.I dette forsøket ble torsk fanget levende og lagret i merd hvor den ble fôret med hhv. lodde og kommersielt torskefôr i 3 måneder. Etter skånsom slakting og utblødning i 30 minutter, ble fisken sløyd og de biologiske data registrert før maskinell filetering enten pre-rigor (innen 2 timer etter død) og post-rigor (etter 4 dagers is-lagring av sløyd fisk). Det ble produsert ryggfileter (Loins) enten med eller uten skinn. Vekt og lengde på ryggfiletene ble registrert ved filetering og på dag 4, 9 og 14 for de pre-rigor produserte filetene, mens de samme målingene ble gjort på dag 9 og 14 for de post-rigor produserte filetene. Resultatene viser at pre-rigor produserte loins med skinn taper mindre vann og krymper mindre. Det var ingen signifikant forskjell i muskel pH og vanninnhold mellom de ulike gruppene. Vannbindingsevnen var signifikant lavere i pre-rigor produserte loins. Fisken som hadde fått tørrfôr hadde signifikant lysere muskel uavhengig av fileteringstidspunktet. Profesjonelle kokker vurderte kvaliteten av loins fra både den tørrfôrede og den loddeforede torsken som meget god.In this experiment, wild captured cod were fed either capelin or commercial dry feed for 3 months prior to either pre-rigor filleting or post-rigor filleting where loins with or without skin on were produced. During a 14 days storage period in ice, the pre-rigor produced loins without skin lost more weight due to the formation of drip. This group also shrank the most. No significant differences were detected in muscle pH and water content between the groups. However, the water holding capacity was significantly lower in the pre-rigor produced loins. The quality of the loins from all groups was evaluated as very good by a group of professional chefs

A simple method to isolate fatty acids and fatty alcohols from wax esters in a wax-ester rich marine oil.

Calanus finmarchicus is one of the most important zooplankton species in the North Atlantic. The zooplankton is currently being harvested and industrially processed to a marine oil product for human consumption as a marine nutraceutical containing long-chain omega-3 polyunsaturated fatty acids. This oil is very rich in wax esters, a lipid class where fatty acids are esterified to long chain fatty alcohols. In this paper we describe a simple method to 1) isolate the wax esters from the other lipid classes present in the oil, 2) hydrolyze the wax esters, and 3) separate the fatty acids from the fatty alcohol, all by means of solid phase extraction. Starting with an average of 322 mg Calanus oil, we obtained 75 mg fatty alcohols and 63 mg fatty acids. Contrary to previously described techniques, our method neither oxidize the fatty alcohols to fatty acids, nor are the fatty acids methylated, allowing the native, unesterified fatty acids and fatty alcohols to be used for further studies, such as in cell culture experiments to study the metabolic effects of these specific lipid fractions rather than the intact oil or wax esters

Torsk fra merd: Pre-rigor produksjon av loins med skinn

I dette forsøket ble torsk fanget levende og lagret i merd hvor den ble fôret med hhv. lodde og kommersielt torskefôr i 3 måneder. Etter skånsom slakting og utblødning i 30 minutter, ble fisken sløyd og de biologiske data registrert før maskinell filetering enten pre-rigor (innen 2 timer etter død) og post-rigor (etter 4 dagers is-lagring av sløyd fisk). Det ble produsert ryggfileter (Loins) enten med eller uten skinn. Vekt og lengde på ryggfiletene ble registrert ved filetering og på dag 4, 9 og 14 for de pre-rigor produserte filetene, mens de samme målingene ble gjort på dag 9 og 14 for de post-rigor produserte filetene. Resultatene viser at pre-rigor produserte loins med skinn taper mindre vann og krymper mindre. Det var ingen signifikant forskjell i muskel pH og vanninnhold mellom de ulike gruppene. Vannbindingsevnen var signifikant lavere i pre-rigor produserte loins. Fisken som hadde fått tørrfôr hadde signifikant lysere muskel uavhengig av fileteringstidspunktet. Profesjonelle kokker vurderte kvaliteten av loins fra både den tørrfôrede og den loddeforede torsken som meget god