Title Utjecaj hranidbe kokoši i temperature skladištenja na kvalitetu konzumnih jaja
Title (english) Effect of hen feeding and storage temperature on the quality of table eggs
Author Igor Vendl
Mentor Zlata Kralik (mentor)
Committee member Zoran Škrtić (predsjednik povjerenstva)
Committee member Dalida Galović (član povjerenstva)
Granter Josip Juraj Strossmayer University of Osijek Faculty of Agrobiotechnical Sciences Osijek (Department of Animal Production and Biotechnology) Osijek
Defense date and country 2020-07-28, Croatia
Scientific / art field, discipline and subdiscipline BIOTECHNICAL SCIENCES Agronomy Animal Husbandry
Abstract Cilj ovog istraživanja bilo je povećanje sadržaja omega-3 masnih kiselina u jajima te utvrđivanje utjecaja hranidbe nesilica na kvalitetu jaja čuvanih u različitim uvjetima skladištenja. Hranidbeni dio pokusa je proveden na ukupno 80 nesilica hibridne linije Tetra SL, koje su bile podijeljene u dva hranidbena tretmana: K= komercijalna krmna smjesa za nesilice i O=krmna smjesa dizajniranog sastava-povećan sadržaj omega-3 masnih kiselina. Analiza kemijskih pokazatelja provedena je kroz tri razdoblja svježa jaja, nakon 7 odnosno 14 dana skladištenja na različitim temperaturama (skladištenje u hladnjaku na temperaturi od +4°C i na sobnoj temperaturi od +22°C). Ukupno je analizirano po skupini 150 jaja (ukupno 300) razreda L (63-73 g). Rezultati istraživanja pokazuju da su nesilice obije ispitivane skupine tijekom pokusnog razdoblja snesle podjednak broj jaja (K=1920 kom. i O=1116 kom.) uz dnevnu konzumaciju hrane od 119,6 g (K) i 118,9g (O). Intenzitet nesivosti bio je visok iznosio je 92-93%. Uočeno je da postoji značajna razlika između K i O skupine u masi jaja i njegovih osnovnih dijelova, ovisno o vremenu mjerenja i temperaturi skladištenja. Ta razlika više je izražena kod jaja skladištenih na sobnoj temperaturi. Fizikalno-kemijski pokazatelji kvalitete jaja skladištenih na temperaturi 4°C i 22°C utvrđeni tijekom tri razdoblja mjerenja (1., 7. i 14. dana) pokazuju da hranidbeni tretman statistički značajno utječe na razlike dobivene kod vrijednosti indeksa oblika (%), pH bjelanjaka te kod pokazatelja kvalitete ljuske (P<0,05). Utjecaj temperature skladištenja i vremena analize značajno su utjecali na visinu bjelanjka (mm), Houghove jedinice, pH bjelanjka i pH žumanjka, dok je utjecaj vremena skladištenja utvrđen kod vrijednosti boje žumanjka. Utjecaj interakcije svih efekata utvrđen je kod vrijednosti pH bjelanjaka i žumanjaka (P<0,001) i te kod vrijednosti čvrstoće ljuske (P=0,036). Korišteni hranidbeni tretman utjecao je na sadržaj masnih kiselina u žumanjcima jaja ispitivanih pokusnih skupina (% u sumi masnih kiselina). U žumanjcima jaja K skupine utvrđen je statistički značajno veći sadržaj ukupnih SFA i n-6 PUFA u odnosu na jaja skupine O (P<0,05), dok je u žumanjcima skupine O utvrđen statistički značajno veći sadržaj ukupnih n-3 PUFA u odnosu na jaja skupine K (P<0,01). Omjer n6 PUFA/ n-3 PUFA bio je povoljniji u jajima O skupine jaja u odnosu na jaja skupine K (2,69: 8,17; P<0,01). Vrijednosti oksidacije lipida u žumanjcima jaja ispitivanih skupina nisu se statistički značajno razlikovale (P>0,05). Provedeno istraživanje potvrđuje da vrijeme analize i temperatura skladištenja značajno utjeću na unutarnje pokazatelje kvalitete jaja, dok hranidbeni tretman ima znaćajan utjecaj na sadržaj masnih kiselina u žumanjcima jaja ispitivanih pokusnih skupina
Abstract (english) The aim of this study was to increase the content of omega-3 fatty acids in eggs and to determine the effect of laying hens feeding on the quality of stored eggs in different storage conditions. Feeding part of experiment was performed on total of 80 laying hens Tetra SL hybrid line, which was divided into two fed diets: K = commercial feed for laying hens and O: designed feed, with increased content of omega-3 fatty acids. The analysis of chemical indicators was performed through three periods; fresh eggs, after 7 days or 14 days at storage on different storage temperatures (refrigerated storage +4°C and at room temperature +22°C). In total 150 eggs per groups were analysed (total 300) of class L (63-73 g). The results of the study showed that hens from both investigation groups during experimental period laid the same number of eggs (K = 1920 pcs. and O = 1116 pcs.) with daily feed consumption of 119,6 g (K) and 118 g (O). The laying intensity was 92-93%. It was observed that there was significant difference between K and O group in egg mass and mass of basic parts of the egg, depending on the measurement time and storage temperature. This difference was more significant with eggs stored at room temperature. Physical-chemical indicators of egg quality stored at 4°C and 22°C temperature was determined during three measurement period (1, 7 and 14 days) and showed that feed treatments have statistically significant influence on index value (%), pH albumen and shell quality (P<0,05). Influence of storage temperature and analysis time significantly affected albumen height (mm), Hough unit, albumen pH, yolk pH, while the influence of storage time was determined in the yolk color value. Influence of the interaction effects was determined on pH albumen and yolk (P<0,001) and on the shell thickness (P=0,036). The used feed treatment influenced on fatty acid composition in the egg yolks of experimental groups (% in sum of fatty acid). In egg yolks of K group significantly higher content of total SFA and n-6 PUFA compered to eggs of O group was determined (P<0,05). In the yolks of the O group was determine significantly higher content of total n-3 PUFA compared to group K (P<0,01). The n-6 PUFA/n-3 PUFA ratio was more favorable in eggs of O group compared to the eggs from K group (2.69:8.17; P<0,01). Lipid oxidation values in egg yolks from both investigation groups did not difer (P>0,05). The performed study confirms that the time of analysis and storage temperature significantly influence on internal indicators of egg quality, while feed treatment has a significantly influence on fatty acid composition in the egg yolks of experimental groups.
Keywords
omega-3
hranidba nesilica
temperatura skladištenja
kvaliteta
oksidacija lipida
Keywords (english)
omega-3 fatty acids
han diet
storage temperature
quality
lipid oxidation.
Language croatian
URN:NBN urn:nbn:hr:151:758776
Study programme Title: Quality and safety of animal products Study programme type: university Study level: postgraduate specialist Academic / professional title: sveučilišni/a specijalist/specijalistica kakvoće i sigurnosti animalnih proizvoda (sveučilišni/a specijalist/specijalistica kakvoće i sigurnosti animalnih proizvoda)
Type of resource Text
File origin Born digital
Access conditions Open access
Terms of use
Public note specijalistički rad
Created on 2020-10-16 10:59:48