Professional paper
Effect of sex, castration and various technological processes on chemical composition of sheep meat and kastradina
Marina Krvavica
orcid.org/0000-0002-4431-5958
; Veleučilište „Marko Marulić“, Petra Krešimira IV 30, Knin
doc. Miljenko Konjačić
; Sveučilište u Zagrebu, Agronomski fakultet, Svetošimunska 25, Zagreb
prof. Boro Mioč
; Sveučilište u Zagrebu, Agronomski fakultet, Svetošimunska 25, Zagreb
Abstract
In order to determine the effect of sex and castration of adult sheep grouped into different categories, and the effect of various technological methods of processing meat (adding spices to brine and extending the phase of meat ripening for 25 days) on the chemical composition of meat and dry-cured meat products, as well as the stability of intramuscular fat during the processing, 66 heads of Pramenka culled from breeding herds were slaughtered and divided into 3 categories consisting of 22 heads: females (F), castrated rams (CR) and non-castrated rams (NR). After the slaughter and the processing of carcasses, the obtained meat was used to produce Kastradina, using the traditional Dalmatian recipe. Samples of meat and Kastradina used in the chemical analysis were taken from the shoulder of each carcass, whereas the right shoulder of each carcass was cured using only sea salt, while the left shoulder of each carcass was ripened in brine to which 1 % seasoning (garlic, bay leaf and rosemary) was added. We collected samples of meat and Kastradina three times (on the day 1, day 35 and day 60 of processing) and subsequently performed a chemical analysis to determine a specific content of dry matter (water), protein, fat and ash. We have also determined the content of NaCl, and both acid (AV) and peroxide value (PV) in Kastradina samples, so as to determine the degree of hydrolysis and the amount of hydroperoxide in intramuscular fat. Results of performed chemical analyses demonstrated that both sex and castration significantly affected the chemical composition of sheep meat, save for the content of dry matter. The largest amount of fat was found in the meat of CR (7.30 %) and the smallest amount in the meat of NR (2.40 %; P<0.01). The amount of fat in the meat of F (5.08 %) varied between the amount of fat in the meat of CR and NR (P<0.05). Since it is dependent on fat ratio, the protein ratio was similar to fat ratio (F - 20.44 %; CR - 17.86 %; NR - 20.64 %), and the only determined difference at the same time represented a statistically significant difference between the CR and the other two categories, namely F and NR (P<0.01). Likewise, differences in the content of ash were also statistically significant (F - 1.06 %; CR - 0.83 %; NR - 1.09 %; P<0.001). We have determined similar mutual ratios for Kastradina after 35 and 60 days of processing. However, in Kastradina the content of individual components increased with the decrease of water content as a result of dehydration. The determined contents of Kastradina after 60 days were therefore as follows: water: F - 38.27 %, CR - 37.68 %, NR - 39.13% (P>0.05); protein: F - 37.87 %, CR - 31.88 % (P<0.01), NR - 41.94 %; fat: F - 15.63 %, CR - 23.48 % (P<0.05), NR - 9.25 % (P<0.01); and ash: F - 8.25 %, CR - 7.63 %; NR - 9.07 % (P<0.05). The amount of NaCl in Kastradina (60 days) was, compared to mutually similar ratios in the category F (5.89 %) and NR (6.49 %,) significantly smaller for the category CR (4.37 %; P<0.01). However, despite the significantly higher fat content, the category of CR had the lowest AV and PV in both stages of ripening of Kastradina (35 and 60 days), with the differences always being statistically significant between the category of CR and NR (P<0.05). We have also recorded an increase of AV and PV during the ripening of Kastradina for every category except NR, which compared to F and CR experienced a sudden decrease of AV at the end of processing and a concurrent, significantly greater increase of PV. This indicated that free fatty acids produced in the category NR probably rapidly oxidised with the remainder of the ripening phase, which led us to assume that the fatty acid profile of NR muscle tissue most probably contained more polyunsaturated fatty acids susceptible to hydrolysis and oxidation. We have also determined a significant positive impact of the addition of spices to brine on the hydrolytic and oxidative stability of Kastradina (P<0.05).
Keywords
Kastradina; sex and castration; chemical composition and oxidative stability of sheep meat
Hrčak ID:
162016
URI
Publication date:
30.6.2016.
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