INFLUENCE OF REFRIGERATION, FREEZING AND DE-FREEZING METHOD ON THE CHEMICAL COMPOSITION, CALORICITY AND CERTAIN RHEOLOGICAL-TEXTURAL TRAITS OF POULTRY MEAT

R.M. Radu-Rusu

Abstract
   The paper brings new data on the chemical composition and energetic value of the poultry meat, under the action of freezing as well as on the way in which meat texture, analysed instrumentally, is influenced by the chosen de-freezing method. Eighty carcasses of chicken broiler of the same origin were analysed and symmetrically randomly distributed in 4 groups: REF-refrigerated meat + 3 groups of frozen meat, thawed through different methods: FDCW-cold water; FDWW-warm water; FDMW-microwaves. The chemical composition revealed increased content of water (+1.02% in breast, +0.79% in thighs) and decreased proteins levels (-2.78% in breast, -2.75% in thighs) in FDCW vs. REF, due to hydro soluble organic matters leakage during de-freezing, as well as to water uptake from the de-freezing environment. Better chemical stability was observed in thighs (p<0.05), and poorer in breast (p<0.001). Refrigerated meat was also richer in calories (+1.06%...+3.04%). Texturally, it was noticed a decrease of frozen meat firmness, compared to the refrigerated one, of: 5.37-6.25% (FDCW), 11.36-13.33% (FDWW), 8.88-9.68% (FDMW) and a similar dynamic of the Warner-Bratzler shear forces: 81.5 N (REF) to 73.5 N (FDWW) (p<0.001, breast) and 80.5 N (REF) to 72.70 N (FDWW) (p<0.001, thighs). The meat preserved through freezing and de-frozen in warm water or under microwaves flow presented the highest textural alterations leading, eventually, to a lower sensorial quality.

Key words: poultry meat, refrigeration, freezing, proteins, texture

INFLUENŢA REFRIGERĂRII, CONGELĂRII ŞI METODEI DE DECONGELARE ASUPRA COMPOZIŢIEI CHIMICE, CALORICITĂŢII ŞI A UNOR PARAMETRI REOLOGICO-TEXTURALI AI CĂRNII DE PASĂRE

R.M. Radu-Rusu

Rezumat
   Lucrarea aduce date noi despre compoziţia chimică şi valoarea energetică a cărnii de pasăre, sub acţiunea congelării dar şi despre modul în care textura cărnii, analizată instrumental, este influenţată de metoda de decongelare. S-au utilizat 80 carcase de pui broiler de aceeaşi provenienţă, distribuite egal în 4 loturi, respectiv: lotul de control REF-carne refrigerată + 3 loturi de carne congelată, supuse decongelării prin metode diferite: CDAR-în apă rece; CDAC-în apă caldă; CDMW-la microunde. Compoziăia chimică a evidenţiat un conţinut mai mare de apă (+1,02% la piept, +0,79% la pulpe) şi mai redus de proteine (-2,78% la piept, -2,75% la pulpe) la CDAR faţă de REF, datorită pierderilor de substanţe organice hidrosolubile la decongelare, prin exsudatul caracteristic, şi absorbţiei de apă din mediul de decongelare. S-a observat o stabilitate chimică superioară a pulpelor (p<0.05), faţă de piept (p<0.001). Carnea refrigerată a fost, de asemenea, mai calorică (+1,06%...+3,04%). Textural, s-a observat reducerea fermităţii cărnii congelate, faţă de cea refrigerată (piept-pulpe), de: 5,37-6,25% (CDAR), 11,36-13,33% (CDAC), 8,88-9,68% (CDMW) şi o dinamică asemănătoare pentru forţele de forfecare Warner-Bratzler: 81,50 N (REF) - 73,50 N (CDAC) (p<0.001, piept) şi 80,50 N (REF) - 72,70 N (CDAC) (p<0.001, pulpe). Carnea conservată prin congelare şi apoi decongelată în apă caldă sau la microunde prezintă cele mai mari deprecieri texturale, conducând probabil la o calitate senzorială mai scăzută.

Cuvinte cheie: carne pasăre, refrigerare, congelare, proteine, textură