Artur Rybarczyk

The influence of myoglobin on the colour of minced pork loin

The influence of the total and chromatic absorbance at wavelengths of 525 nm (A525 and A525p) and 700nm (A700), and the relative content of oxymyoglobin (MbO2), metmyoglobin (MetMb) and deoxymyoglobin (Mb), on the value of the colour parameters (L*, a*, b*, C* and h°) of minced pork loin, were evaluated. Lightness (L*) depended almost entirely on variation in total absorbance at a wavelength of 525 nm. Redness (a*) depended on the forms of myoglobin and A525p, while yellowness (b*) depended mainly on the proportions of the reduced form (Mb), the oxygenated form (MbO2) and the oxidised form (MetMb). Yellowness (b*) significantly increased with a decrease in the relative amount of Mb and an increase in relative amounts of MbO2 and MetMb, although a greater impact was exerted by fluctuations in MbO2 than MetMb. Variability of chroma (C*) depended mainly on proportions of the forms of myoglobin. Hue angle (h°) depended primarily on chromatic absorbance at 525 nm (A525p).

Effect of dietary plant extracts mixture on pork meat quality

Abstract The objective of this study was to investigate the effects of a plant extracts mixture including carvacrol (oregano), cinnamaldehyde (cinnamom), and capsicum oleoresin (Mexican pepper) on the meat quality of pigs. The study was carried out on 60 pigs, divided into two groups (control and experimental), 30 pigs each. The control group was given a basal diet and the experimental group (XT group) received the basal diet supplemented with 80 mg/kg (XT). The fattening of pigs was carried out from a body weight of 30 to 100 kg. The pigs XT group had a lower M. longissimus dorsi (LD) electrical conductivity at 24 hour post-mortem, lower drip loss and cooking loss from the LD muscle, however, had a higher water holding capacity and a* values (redness) in the fresh meat. The plant extracts significantly increased the sensory quality of the fresh meat and the cooked meat.

The effect of calpastatin polymorphism and its interaction with RYR1 genotypes on carcass and meat quality of crossbred pigs

The aim of the study was to establish the relationship between a calpastatin gene (CAST) polymorphism, the ryanodine receptor gene (RYR1) polymorphism and carcass/meat quality traits in crossbred pigs. No significant differences in the analyzed pigs were found between genotypes CC and CT at the locus RYR1 and CD and DD at the locus CAST/MspI in terms of carcass and meat quality. However, a significant association of the CAST/ApaLI polymorphism with carcass quality and meat marbling were observed. The carcasses of AB pigs had significantly higher carcass percentage of lean meat, thinner backfat and thicker muscle, as well as lower meat marbling, as compared with the BB pigs. Furthermore, interactions CAST/MspI × RYR1 and CAST/ApaLI × RYR1 were found significant in relation to all the studied carcass traits. The results presented here imply that the CAST gene recognized with ApaLI may be considered as important in terms of the way it affects porcine carcass quality traits. Moreover, the research has revealed a relationship between CAST and RYR1 genotypes as regards formation of carcass traits in pigs. Follow-up studies, however, should be carried out on larger populations representing all possible CAST genotypes.;

The effects of blast chilling on pork quality.

The aim of this study was to determine the effects of blast chilling of pig carcasses on the physiochemical and sensory properties of the longissimus lumborum muscle. To this end, right half-carcasses were blast-chilled for 70min at -24°C and then for 22h and 50min at 1°C, while left half-carcasses were chilled conventionally at 1°C for 24h. At 2h and 6h post mortem, blast chilling had significantly reduced the temperature of the carcasses, as well as the rate of pH decrease and the rate of increase in EC. It had no significant effect on the ultimate pH or its range, or on EC at 24h post mortem, but it significantly lowered L*, b*, C* and drip loss compared to the conventionally chilled carcasses. Blast chilling adversely affected sensory characteristics such as tenderness and flavor. There were no significant differences between the effects of blast and conventional chilling systems on meat quality between conformation classes.

A comparison of two methods of determining colour change in the assessment of the quality of pork

BACKGROUND The colour of pork is one of the most important measures of meat quality. For the consumer, it is a sign of freshness, crucial for the decision to buy a product. The storage of meat results in constant col- our changes. Differences can be found in all colour parameters, especially chromatic ones, such as redness (a*) and hue angle (h°), as these changes are significantly correlated with a number of quality traits. Colour change can be determined not only by evaluating changes in colour parameters, but also by establishing the change in absorbance of specific wavelengths of light. The aim of this study was to compare the usefulness of these two methods of determining colour change: parameters measured on the CIELAB and CIELCh scales and colour change (%CC) determined based on the absorbance of selected wavelengths of light, i.e. 505, 540, 560, 580 and 630 nm. In this paper, we analysed two methods of measuring colour change in terms of their relevance for meat quality assessment. METHODS The study involved 150 samples of the longissimus lumborum muscle collected from 150 carcasses of pigs slaughtered on an industrial line, weighing 65-107 kg, with an average carcass weight of 86.1 kg. Meat sensory analysis (colour, wateriness, firmness), physicochemical assessment (colour, WHC, pH48) and proximate analysis (moisture, total protein, fat, ash) were carried out. The methods included the determination of (I) changes in colour parameters measured on the CIELAB and CIELCh scales, and (II) colour change (%CC) based on the absorbance of selected wavelengths: 505, 540, 560, 580 and 630 nm. Chromatic absorbance values of a wavelength of 525 nm (A525p) and the relative content of Mb, MbO2 and MetMb were calculated according to the method proposed by Krzywicki (1979). RESULTS Basic chemical composition - with few exceptions - was not significantly correlated with differenc- es in the values of colour parameters (ΔL*, ?a*, ?b*, ΔC*, Δh°) and colour change (%CC). With an increase in scores in the sensory evaluation of colour, wateriness, and firmness, and an increase in WHC and pH48, the differences in lightness (ΔL*) significantly increased and differences in chromatic value (?a*, ?b*, ΔC*, Δh°) and %CC decreased, for all tested combinations of wavelengths. The highest correlation coefficients were observed for ?a* and Δh° and %CC540/630 and %CC580/630, with colour change (%CC540/630 and %CC580/630) showing a stronger correlation with the tested meat quality traits than the differences in redness (?a*) and hue angle (Δh°). We found a very strong correlation between changes in the relative levels of MetMb (ΔMetMb) and colour change (%CC) based on the absorbance of wavelengths of 540 and 505 nm, and 580 and 505 nm (r = 0.950*** and r = 0.967***, respectively). CONCLUSIONS The determination of colour change based on the absorbance of two combinations of wave- lengths, i.e. (I) 540 and 630, and (II) 580 nm and 630 nm, is more useful in the assessment of pork quality than changes in two most relevant parameters of the CIELAB and CIELCh scales, i.e. redness (Δa*) and hue angle (Δh°). Moreover, the determination of absorbance of a wavelength of 630 nm was more useful for determin- ing colour change (%CC) than 505 nm. Colour change (%CC) based on the absorbance of wavelengths of 540 and 505 nm and 580 and 505 nm reflect the changes in the relative amounts of MetMb very well.

Meat quality of mongrel rabbits and the crosses of the California and New Zealand white breeds

Streszczenie. Celem badań było określenie jakości tuszek i mięsa królików bezrasowych i mieszańców ras hodowlanych: kalifornijskiej i nowozelandzkiej białej. Materiał do badań stanowiły tuszki 25 królików, w tym 16 pochodziło od królików bezrasowych i 9 od mieszańców ras: kalifornijskiej (KA) i nowozelandzkiej białej (NB), z zachowaniem w grupach zbliżonego udziału samców i samic. W badaniach wykazano, że tuszki królików mieszańców ras hodowlanych (KA×NB) charakteryzowały się większym udziałem mięsa, a mniejszym kości w porównaniu z królikami bezrasowymi. Króliki mieszańce (KA×NB) w porównaniu z królikami bezrasowymi cechowały się większą wartością pH48 zarówno w mięśniu longissimus lumborum, jak i w mięśniach udowych, co wpłynęło na ciemniejszą (L*) barwę mięśni i większą zdolność utrzymania wody własnej oraz większą zawartość białka rozpuszczalnego w wodzie. Ponadto mięśnie królików KA×NB cechowały się większą zawartością suchej masy, w tym tłuszczu śródmięśniowego, białka ogólnego i popiołu, co wpłynęło na większą wyliczoną ich wartość energetyczną.