magistrsko delo
Mojca Kuhar (Author), Nataša Šegatin (Reviewer), Lea Demšar (Mentor)

Abstract

Namen magistrske naloge je bil proučiti oksidativno stabilnost proteinov (nastanek karbonilov), lipidov in barve med skladiščenjem vakuumsko pakirane jagnjetine in teletine in pri temperaturi 2 °C ± 1 °C do 15 oz. 21 dni. Obenem smo proučili primernost telečjega in jagnječjega hrbta z ledji (mišica longissimus lumborum) za zorenje in optimalen čas za zagotovitev želenih senzoričnih lastnosti, mehkobe in arome. 100 g jagnjetine vsebuje 23,48 g beljakovin, 69,66 g vode in 5,48 g maščobe. Jagnjetina je bila najmehkejša po 11-ih dneh (tako senzorično ocenjena lastnost kot instrumentalno izmerjena sila, ki se je zmanjšala za 61 %), najboljša aroma po 15-ih dneh zorenja. Medtem je jagnjetina postala značilno svetlejša in bolj nasičena (povišane vrednosti L*, a* in b*), povečala se je vsebnost sekundarnih produktov oksidacije lipidov (1,7-krat več malondialdehida), vsebnost proteinskih karbonilov pa se je zmanjšala na začetno raven, kljub prvotnemu povečanju po 7-ih dneh zorenja. 100 g teletine vsebuje 22,47 g beljakovin, 70,27 g vode in 5,32 g maščobe. Teletina je bila najmehkejša (tako senzorično cenjena lastnost kot instrumentalno izmerjena sila, ki se je zmanjšala za 33 %), najbolj sočna in z najboljšim vonjem in aromo po 21-dnevnem zorenju. V tem času se barva ni opazneje spremenila (izjema je povišanje vrednosti b*), prav tako se ni spremenila oksidacijska stabilnost lipidov, povečala pa se je vsebnost proteinskih karbonilov (že po 14-ih dneh zorenja). Za realno vrednotenje obsega oksidacije beljakovin v jagnjetini in teletini, moramo upoštevati, da 7-dnevno zamrzovanje vzorca pred analizo značilno zmanjša vsebnost proteinskih karbonilov (32 %). Ugotovili smo, da sta jagnječji in telečji hrbet z ledji primerna kosa za zorenje. Optimalen čas zorenja je 15 dni za jagnjetino in 21 dni za teletino.

Keywords

telečje meso;jagnječje meso;zorenje mesa;oksidacija beljakovin;produkti oksidacije;proteinski karbonili;instrumentalne metode;senzorične lastnosti;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Kuhar]
UDC: 637.5:543.632.52:543.92
COBISS: 27028227 Link will open in a new window
Views: 443
Downloads: 166
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Other data

Secondary language: English
Secondary title: The content of protein carbonyls in veal and lamb during ageing
Secondary abstract: The aim of this thesis is to determine the oxidative stability of proteins (formation of carbonyls), lipids and colour of vacuum packed lamb and veal at a constant temperature of 2 °C ± 1 °C up to 15 days or 21 days. The suitability of veal and lamb loin (longissimus lumborum) for ageing and optimal ageing time to achieve optimum sensory properties, tenderness and aroma has been determined. A sample of 100 g of lamb meat contains 23.48 g of protein, 69.66 g of water and 5.48 g of fat. Lamb samples were the most tender after 11 days (both the sensory assessed property and the instrumentally measured share force that decreased by 61%) and the best aroma after 15 days of ageing. In the meantime, the lamb became significantly brighter and more saturated (higher L*, a* and b* values), the content of secondary lipid oxidation products increased (1.7 times higher amount of malondialdehyde), and the content of protein carbonyls decreased to the initial value, despite an initial increase after 7 days of ageing. A sample of 100 g veal contains 22.47 g of protein, 70.27 g of water and 5.32 g of fat. Veal samples were the most tender (both the sensory assessed property and the instrumentally measured share force that decreased by 33%), juiciest and best in odour and aroma after 21 days of ageing. During this period, the colour did not change significantly (except for an increase in the b* value), nor did the amount of oxidation products of the lipids change, but the protein carbonyl content increased (after 14 days of ageing). For a realistic evaluation of the protein oxidation rate in lamb and veal, it should be noted that a 7-day freezing of the sample before analysis significantly reduces the protein carbonyl content (32%) We found that lamb and veal loins with loin are suitable pieces for maturation; the optimal ageing time is 15 days for lamb and 21 days for veal.
Secondary keywords: veal;lamb;meat ageing;protein oxidation;oxidation products;protein carbonyls;instrumental methods;sensory properties;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: XI, 59 f., [8] f. pril.
ID: 12021442