Seasonal variation of biochemical composition of Noah's ark shells (Arca noae L. 1758) in a Tunisian coastal lagoon in relation to its reproductive cycle and environmental conditions

2018 ◽  
Vol 31 ◽  
pp. 14 ◽  
Author(s):  
Feriel Ghribi ◽  
Dhouha Boussoufa ◽  
Fatma Aouini ◽  
Safa Bejaoui ◽  
Imene Chetoui ◽  
...  

The seasonal changes in biochemical composition of the edible bivalve Arca noae harvested from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia) were investigated from October 2013 to September 2014. Potential food sources and nutritional quality indices (NQI) were determined by analyzing the fatty acid profiles of their tissues during an annual reproductive cycle. Results showed that A. noae had moisture (73.8–82%) and protein (24.1–58.6% dry weight) as major components, followed by lipid (10.4–28.8% dry weight) and glycogen (4.05–14.6% dry weight). A. noae accumulated lipid and glycogen for gonadal development during both maturation periods (late autumn/late spring–summer) to be used during spawning periods (winter/late summer–early autumn). However, proteins were mainly used to support reproductive allocation and played an important role on the energetic maintenance. Lipid and glycogen were found to be significantly related to temperature, salinity and chlorophyll a (p < 0.05). An increase of condition index (CI) was observed during spring and early summer when both temperature and food supply increased. The total fatty acid (TFA) profile of Ark shells was dominated by polyunsaturated fatty acids (PUFA) (33.8–49.6%), followed by saturated (SFA) (29.1–43.1%) and monounsaturated fatty acids (MUFA) (20.77–28.3%). A. noae soft tissues were also rich in macro-minerals (Na, Ca and Mg). The analysis of fatty acid trophic markers revealed that the diet of A. noae during the year of study was based on mixture food mainly on phytoplankton followed by zooplankton and other sources (bacteria, seagrass and macroalgae). Furthermore, the nutritional quality indices have revealed that A. noae is an excellent source of nutrients and a healthy food for human consumption. These data are useful to the conservation of natural stocks of A. noae and the development of sustainable aquaculture production of this shellfish species in the Bizerte lagoon.

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 416
Author(s):  
Francesca Biandolino ◽  
Isabella Parlapiano ◽  
Giuseppe Denti ◽  
Veronica Di Nardo ◽  
Ermelinda Prato

The effect of cooking (barbecue-grilling, boiling, microwaving, oven cooking and frying) on lipids, fatty acids (FAs) and lipid quality indices of the mussel Mytilus galloprovincialis was investigated. In general, all processing methods significantly (p < 0.05) modified the fatty acid profiles of mussels, although with major changes in fried samples, which exhibited the lowest saturated fatty acids and n-3 and highest polyunsaturated (PUFA) and n-6 FAs content. A significant decrease in the n-3 PUFA from the raw sample to five cooking methods was observed. The n-3/n-6 ratio decreased from raw (6.01) to cooked mussels, exhibiting the lowest value in fried ones (0.15). C20:5 n-3 and C22:6 n-3 significantly decreased during all cooking processes, and overall in fried mussels. It can be concluded that cooking does not compromise the nutritional quality of mussels except with frying, although it resulted in a decrease of the atherogenic and thrombogenic indices.


2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Le Xuan Tuan ◽  
Tran Thi Minh Hang

Microalgae species, such as Amphiprora alata, Chaetoceros muelleri, Nannochloropsis oculata, Navicula tuscula and Chlorella vulgaris from mangrove area of Xuan Thuy National Park are usually used as food sources for fishes, shrimps and bivalves and very environment friendly. The samples of these microalgae were enriched, isolated and purified in F/2 medium with salinity of 20%. The purifed colonies were cultured in media with different salinity in 14 days to find out the most optimal medium for the best growth as well as the stage yielding maximum living mass. These microalgae were then cultured in their optimal media at salinity of 25% until they reached their maximum living mass stage. They were cultivated and analyzed of their fatty acid, protein carbonhydrate components and percentages. The research has identified 24 fatty acids in 5 phytoplankton species. Unsaturated fatty acids components of Chaetoceros muelleri, Nannochloropsis oculata are the highest (76,35% and 71,17%), and fatty acid components of are medium Chlorella vulgaris and Amphiprora alata (59,24% and 52,21%), meanwhile, Navicula tuscula has 29.56% of unsaturated fatty acids.  Amphiprora alata and Chlorella vulgaris have protein content of 8.1g per 100g dry weight and 4.44g per 100g dry weight accordingly. Carbohydrate content of Nannochloropsis oculata and Navicula tuscula are 11.8g per 100g dry weight and 5.47g per 100g dry weight, respectively. 


Author(s):  
Ikumi Umetani ◽  
Eshetu Janka ◽  
Michal Sposób ◽  
Chris J. Hulatt ◽  
Synne Kleiven ◽  
...  

AbstractBicarbonate was evaluated as an alternative carbon source for a green microalga, Tetradesmus wisconsinensis, isolated from Lake Norsjø in Norway. Photosynthesis, growth, and lipid production were studied using four inorganic carbon regimes: (1) aeration only, (2) 20 mM NaHCO3, (3) 5% (v/v) CO2 gas, and (4) combination of 20 mM NaHCO3 and 5% CO2. Variable chlorophyll a fluorescence analysis revealed that the bicarbonate treatment supported effective photosynthesis, while the CO2 treatment led to inefficient photosynthetic activity with a PSII maximum quantum yield as low as 0.31. Conversely, bicarbonate and CO2 treatments gave similar biomass and fatty acid production. The maximum growth rate, the final cell dry weight, and total fatty acids under the bicarbonate-only treatment were 0.33 (± 0.06) day−1, 673 (± 124) mg L−1 and 75 (± 5) mg g−1 dry biomass, respectively. The most abundant fatty acid components were α-linolenic acid and polyunsaturated fatty acids constituting 69% of the total fatty acids. The fatty acid profile eventuated in unsuitable biodiesel fuel properties such as high degree of unsaturation and low cetane number; however, it would be relevant for food and feed applications. We concluded that bicarbonate could give healthy growth and comparative product yields as CO2.


Parasitology ◽  
1983 ◽  
Vol 86 (1) ◽  
pp. 57-71 ◽  
Author(s):  
D. W. T. Crompton ◽  
Anne Keymer ◽  
A. Singhvi ◽  
M. C. Nesheim

SUMMARYThe numbers, distribution in the small intestine, sexual development and growth (dry weight) of 5-week-old Moniliformis dubius (Acanthocephala) were investigated experimentally in adult, female CFHB rats fed on theoretically isoenergetic diets containing known amounts of fructose in combination with either maize-oil fatty acids or maize oil and two concentrations of casein. There was no obvious development of M. dubius when there was no fructose in the host's diet. In contrast, estimated consumption by the host of as little as about 2 g of fructose during the 5-week infection period was accompanied by marked sexual dimorphism and weight gain in most of the M. dubius present. The dry weights of M. dubius of both sexes were positively correlated with fructose concentrations ranging from 0 to 2·5 % (w/w) in the diets containing fatty acids. Significant, but not substantial, increases in M. dubius dry weight were observed as the dietary fructose concentration was raised to 12 % (w/w). Similar trends were observed when the fructose was offered to the infected rats with maize oil, but in general, fructose added to the fatty-acid based diets supported most M. dubius growth. Differences in the distribution pattern of the worms in rats fed on the fatty-acid or maize-oil based diets were observed and their possible significance is discussed.


2018 ◽  
Vol 108 (3) ◽  
pp. 594-602 ◽  
Author(s):  
Susan K Raatz ◽  
Zach Conrad ◽  
Lisa Jahns ◽  
Martha A Belury ◽  
Matthew J Picklo

ABSTRACT BACKGROUND High-oleic (HO) seed oils are being introduced as replacements for trans fatty acid (TFA)–containing fats and oils. Negative health effects associated with TFAs led to their removal from the US Generally Recognized As Safe list. HO oils formulated for use in food production may result in changes in fatty acid intake at population levels. Objectives The purposes of this study were to 1) identify major food sources of soybean oil (SO) and canola oil (CO), 2) estimate effects of replacing SO and CO with HO varieties on fatty acid intake overall and by age and sex strata, and 3) compare predicted intakes with the Dietary Reference Intakes and Adequate Intakes (AIs) for the essential fatty acids (EFAs) α-linolenic acid (ALA) and linoleic acid (LA). Design Food and nutrient intakes from NHANES waves 2007–2008, 2009–2010, 2011–2012, and 2013–2014 in 21,029 individuals aged ≥20 y were used to model dietary changes. We estimated the intake of fatty acid with the replacement of HO-SO and HO-CO for commodity SO and CO at 10%, 25%, and 50% and evaluated the potential for meeting the AI at these levels. RESULTS Each modeling scenario decreased saturated fatty acids (SFAs), although intakes remained greater than recommended for all age and sex groups. Models of all levels increased the intake of total monounsaturated fatty acids (MUFAs), especially oleic acid, and decreased the intake of total polyunsaturated fatty acids (PUFAs), particularly LA and ALA. Replacement of traditional with HO oils at 25–50% places specific adult age and sex groups at risk of not meeting the AI for LA and ALA. Conclusions The replacement of traditional oils with HO varieties will increase MUFA intake and reduce both SFA and PUFA intakes, including EFAs, and may place specific age and sex groups at risk of inadequate LA and ALA intake.


Author(s):  
Shinya Ikematsu ◽  
Ipputa Tada ◽  
Yasuma Nagasaki

Petroleum reserves have been decreasing in recent years and microalgae are attractive as a potential source of new biomass petroleum. Microalgae are unicellar microscopic algae and most species microalgae produce lipids. In particular, Botryococcus braunii produces large amount of lipids found with nearly 70% on the basis of the dry weight. This chapter reviews high lipid-producing microalgae found from Okinawa area around National Institute of Technology, Okinawa College (NIT, Okinawa). The microalgae collected were isolated on an AF-6 agar plates, and incubated in AF-6 medium. The fatty acids were extracted from the algae, converted into fatty acid methyl esters, and analysed by GC/MS. As a result, two microalgae strains were identified that the produced fatty acids was loaded in the algae with nearly 20% in the dry weight base. In addition, these two microalgae strains produced palmitic acid as nearly 40% of the total produced lipids. Therefore, the two microalga strains isolated are potentially and highly efficient for the organisms applied for the production of biodiesel fuel.


2001 ◽  
Vol 67 (11) ◽  
pp. 5254-5260 ◽  
Author(s):  
Yves Poirier ◽  
Nadine Erard ◽  
Jean MacDonald-Comber Petétot

ABSTRACT Medium-chain-length polyhydroxyalkanoates (PHAs) are polyesters having properties of biodegradable thermoplastics and elastomers that are naturally produced by a variety of pseudomonads.Saccharomyces cerevisiae was transformed with thePseudomonas aeruginosa PHAC1 synthase modified for peroxisome targeting by the addition of the carboxyl 34 amino acids from the Brassica napus isocitrate lyase. The PHAC1 gene was put under the control of the promoter of the catalase A gene. PHA synthase expression and PHA accumulation were found in recombinantS. cerevisiae growing in media containing fatty acids. PHA containing even-chain monomers from 6 to 14 carbons was found in recombinant yeast grown on oleic acid, while odd-chain monomers from 5 to 15 carbons were found in PHA from yeast grown on heptadecenoic acid. The maximum amount of PHA accumulated was 0.45% of the dry weight. Transmission electron microscopy of recombinant yeast grown on oleic acid revealed the presence of numerous PHA inclusions found within membrane-bound organelles. Together, these data show that S. cerevisiae expressing a peroxisomal PHA synthase produces PHA in the peroxisome using the 3-hydroxyacyl coenzyme A intermediates of the β-oxidation of fatty acids present in the media. S. cerevisiaecan thus be used as a powerful model system to learn how fatty acid metabolism can be modified in order to synthesize high amounts of PHA in eukaryotes, including plants.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
A Varga ◽  
E Sarkadi Nagy ◽  
L Zámbó ◽  
É Illés ◽  
M Bakacs ◽  
...  

Abstract Trans fatty acids are formed during the industrial processing of food, and are proven to be harmful for the human body. They have been associated with increased risk of cardiovascular disease, abdominal obesity, diabetes, and certain types of cancer. Decree 71/2013. (XI. 20.) of the Ministry of Human Capacities, which has been in force since 2014, defines the highest permitted amount of trans fats in food products placed on the market in Hungary. The impact of the decree on the industrially produced trans fatty acids (iTFA) availability and population intake was assessed in 2017. Results demonstrated that iTFA were replaced by other fatty acids due to the legislation. In 2019, we investigated food groups which had high measured TFA content before the regulation entered into force and compared the total fat and fatty acid profiles to the same brand or similar products being on the market afterwards. In collaboration with the World Health Organization, this was the first assessment to determine to which extent manufacturers increased saturated fat (SFA) content of foodstuffs to reduce iTFA content. In those product groups, which were identified as significant food sources of iTFA before introducing the regulation (biscuits, coffee creamers and flavorings, sweets, bakery products, confectionary, wafers, margarines) we found no significant changes in the total fat content, while in most foodstuffs the average proportion of SFA was higher after reformulation, as iTFA were mainly substituted with SFA in 61% of the products, with cis-MUFA in 25% and cis-PUFA in 14% of the products, respectively. Evidence from this analysis supports concerns that eliminating iTFA in certain foodstuffs leads to unwanted substitution with saturated fat, hence reducing the possible health benefits. Given the high SFA intake and the unfavourable cardiovascular statistics in Hungary, the consumption frequency and portion size control of these products are advised. Key messages Monitoring the changes of food composition is important in order to evaluate the effect of the regulation. Manufacturers should be encouraged to reduce the SFA content to a technologically feasible level.


1992 ◽  
Vol 70 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Branka Stevanovic ◽  
Pham Thi Anh Thu ◽  
Fernando Monteiro de Paula ◽  
Jorge Vieira da Silva

Endemic Balkan species Ramonda serbica and Ramonda nathaliae (Gesneriaceae) are rare resurrection flowering plants, known to withstand repeated cycles of desiccation–rehydration in their natural habitat. Analysis of their leaf lipids and fatty acids revealed a rather small amount of total lipids (15.8 mg/g dry weight in R. serbica and 19.5 in R. nathaliae) and galactolipids, particularly the monogalactosyl-diacylglycerol, considerably poorer in linolenic acid in comparison to other flowering plants (55% for R. nathaliae and 64% for R. serbica). Severe desiccation leads to a drastic loss in total lipids (76% in R. serbica and 71.5% in R. nathaliae), especially in monogalactosyl-diacylglycerol, but the recovery is extremely rapid and thorough upon the rewetting. A shift towards the more saturated oleic and linoleic acids in galactolipids occurs at a different time and to a different degree in the two species, and it is not evenly repaired. Ramonda serbica, known to be somewhat less resistant, shows a wider range of lipid changes. Key words: lipid, fatty acids, desiccation-tolerant plants, Ramonda serbica, Ramonda nathaliae.


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