Maščobnokislinski profil gojenih postrvi

Luzar, Urška (author), Demšar, Lea (mentor), Lušnic Polak, Mateja (co-mentor)

V magistrski nalogi smo preučili povezavo med kemijsko in maščobnokislinsko sestavo krmnih mešanic ter postrvi (Oncorhynchus mykiss). Vzorčenje desetih vzorcev rib in krmnih mešanic smo spomladi leta 2016 izvedli v različnih slovenskih ribogojnicah. V krmnih mešanicah in ribah smo z in situ transesterifikacijo in plinsko kromatografijo določili skupno 52 maščobnih kislin, kemijsko sestavo pa po metodah AOAC. V povprečju 100 g krmne mešanice vsebuje 7,4 g vode, 47,7 g beljakovin, 6,09 g pepela in 21,4 g maščob. Od tega je od skupnih maščobnih kislin 47,8 ut. % enkrat nenasičenih, 34,0 ut. % večkrat nenasičenih in 18,1 ut. % nasičenih, s PS razmerjem (razmerje med večkrat nenasičenimi in nasičenimi maščobnimi kislinami) 1,88, razmerjem n-6/n-3 maščobnimi kislinami 1,74, 0,80 ut. % trans maščobnih kislin ter 3,28 ut. % dolgoverižnih n-3 maščobnih kislin. V povprečju 100 g ribjega mesa vsebuje 76,1 % vode, 21,4 g beljakovin, 1,34 % pepela in 2,52 % maščob, kjer je od vseh maščobnih kislin 42,1 ut. % enkrat nenasičenih, 38,2 ut. % večkrat nenasičenih in 18,9 ut. % nasičenih, s PS razmerjem 2,02, razmerjem n-6/n-3 maščobnimi kislinami 0,98, 0,95 ut. % trans maščobnih kislin ter 13,25 ut. % dolgoverižnih n-3 maščobnih kislin. Deleži maščobnih kislin α-linolenske (ALK; C18:3n-3), eikozapentaenojske kisline (EPK; C20:5n-3) in dekozaheksaenojske kisline (DHK; C22:6n-3) nakazujejo možen vpliv krmnih mešanic oz prehrane postrvi na metabolizem maščob v postrveh, za kar pa so potrebne še nadaljne raziskave.

• Language: Slovenian
• Keywords: postrvi, Oncorhynchus mykiss, maščobne kisline, maščobnokislinska sestava, krmne mešanice za ribe
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [U. Luzar]
• Year: 2018
• PID: 20.500.12556/RUL-103343
• UDC: 637.56:597.552.56:543.635.3
• COBISS.SI-ID: 4960120
• Publication date in RUL: 16.09.2018

Secondary language

• Language: English
• Title: Fatty acid profile of farmed trout (Oncorhynchus mykiss)

Abstract

In this thesis the linkage between the basic chemical and fatty acid composition of trout feed and trout (Oncorhynchus mykiss) meat was investigated. A total of ten trout and belonging feed from different slovenian fish farms were collected and included in this research during spring season in 2016. The content of 52 fatty acids of feed and trout meat was determined by in-situ transesterification and capillary column gas-liquid chromatography and chemical composition according to AOAC methods. On average, 100 g of trout feed contains 7,4 g of moisture, 47,7 g of proteins, 6,09 g of ash and 21,4 g of fat. Regarding fatty acid composition 47,8 wt. % of all fatty acids belong to monounsaturated, 34,0 wt. % to polyunsaturated and 18,1 wt. % to saturated fatty acids, with PS ratio (the ratio between polyunsaturated and saturated fatty acids) 1,88, n-6/n-3 ratio 1,74, 0,80 wt. % of trans fatty acids and 3,28 wt. % of very long chain n-3 fatty acid. On average, 100 g of trout meat contains 76,1 g of moisture, 21,4 g of proteins, 1,34 g of ash and2,52 g of fat, where for fatty acid composition 42,1 wt. % belongs to monounsaturated, 38,2 wt. % to polyunsaturated and 18,9 wt. % to saturated fatty acids, with PS ratio 2,02, n-6/n-3 ratio 0,98, 0,95 wt. % of trans and 13,25 wt. % of very long chain n-3 fatty acids. Shares of α-linoleic (ALA; C18:3n-3), eicosapentaenoic acid (EPA; C20:5n-3) and docosahexaenoic acid (DHA; C22:6n-3) observed here suggest possible effect of feed (diet) source on metabolism of fat in trout meat and requires further investigation.

• Keywords: rainbow trout, Oncorhynchus mykiss, fatty acids, fatty acid composition, trout feed