Władysław Migdał

The effect of dietary CLA supplementation on meat and eating quality, and the histochemical profile of the m. longissimus dorsi from stress susceptible fatteners slaughtered at heavier weights.

The influence of adding 2% CLA to the morning feed of a group of 20 crossbred fatteners from 70 to 130 kg on meat quality, eating quality and dietetic value of m. longissimus dorsi was evaluated compared with a group of 20 controls. Addition of 2% CLA in feed did not influence fattening and slaughter results and also some traits of meat and eating quality. The only significant differences were observed in dry matter content, in meat flavour and L(∗), b(∗), and hue angle value. Meat from fatteners from the experimental group had a statistically significant higher content of CLA (P⩽0.01) and lower content of unsaturated fatty acids especially C18: 2, C18: 1 and C20: 4, PUFA fatty acids (P⩽0.01) and a reduction in the ratio of n-6: n-3 PUFA (P⩽0.01). No statistically significant influence of CLA on the content of cholesterol was observed. The results of the current histochemical study showed that dietary CLA supplementation significantly increased both the number and diameter of white fibres, and correspondingly reduced the number and diameter of red fibres. The percentage and diameter of intermediate fibres was unaffected by CLA.

Effect of bioactive substances found in rapeseed, raspberry and strawberry seed oils on blood lipid profile and selected parameters of oxidative status in rats

Rapeseed, strawberry and raspberry seed oils are a rich source of polyunsaturated fatty acids and antioxidants such as tocols, bioflavonoids and phytosterols. The aim of the study was to determine changes in the blood lipid profile of rats fed with rapeseed, strawberry and raspberry seed oils and their effects on selected parameters of oxidative status. The experiment was carried out on male Wistar rats. The oils were administered by oral gavage for 5 weeks once daily at the dose of about 0.8 ml per rat. Blood samples were taken before and after supplementation period. The activity of superoxide dismutase (SOD) and glutathione peroxidase (cGPx) was assessed in erythrocytes and contents of triglycerides (TG), total cholesterol, low-density fraction of cholesterol (LDL) and high-density fraction of cholesterol (HDL) were assessed in plasma. The experiment shows that oils supplemented in the diet for 5 weeks had no significant effect on the level of triglyceride (TG), total cholesterol as well as HDL and LDL fractions. Reduced activity of cGPX and SOD in the group of rats receiving raspberry and strawberry seed oils suggests that these native oils may contribute to oxidative stability (improves antioxidant status). Thus, strawberry and raspberry seed oils can be considered as special biological oils, which constitute potential nutraceuticals reducing oxidative stress.

Microbiological and chemical safety concerns regarding frozen fillets obtained from Pangasius sutchi and Nile tilapia exported to European countries

BACKGROUND Microbiological and chemical safety concerns regarding frozen fillets from pangasius catfish (Pangasius hypophthalmus) exported to Poland, Germany and Ukraine and Nile tilapia (Oreochromis niloticus) exported to Poland and Germany were investigated by analyzing heavy metal residues, microbiological hazards, biogenic amines, and thiobarbituric acid (TBA) and total volatile basic nitrogen (TVB-N) content. RESULTS The heavy metal residues from all studied samples were far lower than the limits established by authorities. The most abundant biogenic amine found was histamine, with a maximum content of 9.6 mg 100 g(-1) , found in pangasius exported to Poland. The total viable counts were from 2.8 log cfu g(-1) in pangasius exported to Ukraine to 4.3 log cfu g(-1) in pangasius exported to Germany. Vibrio spp. were present in 70-80% of all studied pangasius groups, whereas there no Vibrio spp. were found in the studied tilapia samples. 30% of Pangasius fillets exported to Poland were contaminated with coagulase-positive staphylococci. No E. coli was found in any of the studied samples. Although the results of TBA analysis differed significantly between studied groups, the malonic aldehyde content in all studied groups was still very low. The TVB-N content in frozen fillets from pangasius was significantly lower than in frozen tilapia fillets. CONCLUSIONS We reported that pangasius catfish frozen fillets were widely contaminated with Vibrio spp., which could prove hazardous for the final consumer if the fish is eaten raw or undercooked. The rest of the analysis showed no other reason for concern associated with Nile tilapia and Pangasius catfish frozen fillet consumption.

Native Oils from Apple, Blackcurrant, Raspberry, and Strawberry Seeds as a Source of Polyenoic Fatty Acids, Tocochromanols, and Phytosterols: A Health Implication

The oils from strawberry, blackcurrant, raspberry, and apple seeds were characterized by a high content of unsaturated fatty acids (90.8%, 88.6%, 94.0%, and 86.9%, resp.). Strawberry and raspberry oils had high levels of C18:2 (45.4% and 49.0%) and αC18:3 (29.0% and 33.0%, resp.). Blackcurrant oil was the richest source of γC18:3 (18.5%) and C18:4 (3.6%). Apple oil had high levels of C18:2 (55.5%) and C18:1 (29.4%). Blackcurrant oil had 229.5 mg/100 g of tocochromanols, predominantly γ-tocopherol (117.8 mg/100 g) and α-tocopherol (84.3 mg/100 g). Raspberry oil was rich in γ-, α-, and δ-tocopherol (193.5; 65.6; and 32.2 mg/100 g, resp.). Strawberry oil contained γ- and δ-tocopherol, 49.0 and 6.1 mg/100 g, respectively. Apple contained all isomers of α-, β-, γ-, and δ-tocopherols at 41.7, 62.7, 13.6, and 21.8 mg/100 g, respectively. The level of tocotrienols in the analysed oils ranged from 0.85 to 6.73 mg/100 g. Ten different phytosterols were found in the tested oils. The richest sources of phytosterols were blackcurrant oil (6824.9 g/g) followed by raspberry (5384.1 g/g), strawberry (4643.1 g/g), and apple oil (3460.0 g/g). The dominant compound in the analysed oils was sitosterol, from 2630 g/g in apple oil to 3630 g/g in blackcurrant oil.

Assessment of Color and Sensory Evaluation of Frozen Fillets from Pangasius Catfish and Nile Tilapia Imported to European Countries

The current study was designed to assess the color and sensory evaluation of frozen fillets of Pangasius catfish and Nile tilapia imported to Poland, Germany, and Ukraine in order to evaluate the possible impact of negative media image of these fish fillets on the sensory expectations of the consumers. The study used two trials of sensory evaluation: Blind and informed, on a group of untrained respondents and additional color analysis using the Commission Internationale de l’Éclairage (CIE) L*a*b* scale. The lowest grades during sensory evaluation in all measured parameters were given to Pangasius imported to Ukraine and Poland. The grades of Pangasius and tilapia imported to Germany were similar and significantly higher than of other Pangasius groups. Generally tilapia fillets were marked as better than Pangasius fillets. Moreover the present study found that there was considerable percentage of customers which are susceptible to various commercial frauds since they marked Pangasius higher when they thought they are consuming turbot. This study also showed that the negative image of Pangasius presented through various mass-media might have a negative impact on consumer’s perspective of Pangasius consumption.

The quality of carp (Cyprinus carpio L.) cultured in various Polish regions

BACKGROUND Although environmental factors greatly affect the quality of carp meat, no regulations impose labelling the place of cultivation of freshwater fish. That is why the purpose of this study was to determine the quality of carp meat cultivated in several regions of Poland as well as to assess the necessity of implementing such regulations. RESULTS The influence of the cultivation region on colour, nutrition value, health safety and sensory quality of carp meat was assessed. The analysis included colour measurement, determination of fatty acid profile and sensory evaluation of carp muscle. Moreover, microbiological analysis of the fish surface was performed. The results show that the place of cultivation does not influence the lightness (L*) of fillet, but has an impact on other colour parameters (a*, b*). The microbiological quality of fish from all studied farms was satisfactory, since no pathogenic microorganisms were observed on the fish surface. The fatty acid profile was fairly varied (P < 0.01), depending on the place of cultivation. CONCLUSION Since final results seem ambiguous, further analyses of quality features of carp from various regions and cultures should be performed, before any recommendation for the necessity of labelling the place and method of cultivation should be suggested.

A comparison of selected biochemical characteristics of meat from nutrias (Myocastor coypus Mol.) and rabbits (Oryctolagus cuniculus) / Porównanie wskaźników biochemicznych mięsa nutrii (Myocastor coypus Mol.) i królików (Oryctolagus cuniculus)

Abstract The aim of this study was to compare major biochemical properties of nutria meat with relevant composition and texture data of rabbit carcasses. The meat from nutria m. semimembranosus (MS; thigh muscle) contained 29.54% dry matter (DM), 20.05% total protein (TP), 7.83% total fat (TF) and 1.23% total ash (TA). The ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) was lower in nutria than in rabbit meat (0.55-0.58 and 0.93-0.94, respectively). The n-6/n-3 PUFA ratio was 15.3 (MS) and 11.22 (m. longissimus dorsi, MLD; loin) in nutria meat and 7.55 and 8.08 respectively in rabbit meat, which appeared more beneficial for the consumer. Among the most important texture parameters, hardness ranged from 66 for MS to 73 N for MLD, and overall chewiness was 23 N. The collagen content was between 0.68 and 0.72%. The results show that in comparison with rabbit meat, nutria meat has valuable properties and is recommended for the human diet. Streszczenie Celem badań było porównanie wskaźników biochemicznych mięsa nutrii i królików. Mięso nutrii charakteryzowało się wyższą zawartością tłuszczu (od 3,12% m. longissimus dorsi do 7,83% m. semimembranosus) w porównaniu z mięsem króliczym (odpowiednio 0,7 i 1,41%). Stosunek wielonienasyconych do nasyconych kwasów tłuszczowych w mięsie nutrii wynosił 0,55-0,58, natomiast w mięsie króliczym 0,93-0,94. Stosunek wielonienasyconych kwasów tłuszczowych n-6/n-3 w mięsie nutrii był mniej korzystny dla konsumenta i wynosił 15,3 (m. semimembranosus) i 11,22 (m. longissimus dorsi) w porównaniu z mięsem króliczym (odpowiednio 7,55 i 8,08). Mięso nutrii w porównaniu do mięsa króliczego charakteryzowało się mniejszą zawartością białka oraz większą zawartością kolagenu. Wyższa zawartość kolagenu spowodowała, że mięso nutrii było twardsze i wymagało większej siły cięcia. Jednocześnie mięso nutrii było ciemniejsze (L* od 31,72 do 34,56) w porównaniu z mięsem króliczym (L* od 46,39 do 48,88). Mięśnie nutrii charakteryzują się wyższym wskaźnikiem pH w porównaniu z mięśniami królików i różnią się przebiegiem stężenia pośmiertnego rigor mortis. Najniższą wartość pH w mięśniach nutrii stwierdzono w 10. godzinie po uboju, natomiast w mięśniach królików już w 5. godzinie po uboju. Wysokie pH mięsa nutriowego może sprzyjać szybszemu psuciu się tego mięsa. Dobre parametry mięsa nutriowego wskazują, że jest to mięso delikatne, nadające się zarówno do przetwórstwa (produkcja kiełbas i pasztetów), jak i jako mięso kulinarne do pieczenia i smażenia. Może być mięsem alternatywnym dla innych gatunków, co pozwoli zachować nutrie jako gatunek hodowlany i zwierzęta rzeźne w polskiej hodowli.

The effect of hyaluronic acid addition on the properties of smoked homogenized sausages

BACKGROUND This research studied the possibility of using hyaluronic acid (HA) as a food additive for meat emulsions to create a novel functional food with improved rheological and water binding properties. Sausages with 200 and 500 g kg-1 water addition were supplemented with 0, 0.01, 0.05 and 0.1 g kg-1 of HA and stored for 14 days in vacuum. Rheology, texture, weight losses, proximate composition and microbiological analyses were performed together with the sensory evaluation of produced sausages. RESULTS Surprisingly, the results show that the addition of 0.05 and 0.1 g kg-1 HA reduced yield and the stability of meat emulsion by causing water outflow from the product and decreased the sensory scores of the produced sausages. The sausage with 500 g kg-1 water and 0.01 g kg-1 HA addition was the only economically viable option for introducing the product on the market. CONCLUSION HA has a potential of being a perfect functional food additive for meat industry, although further research regarding processing conditions should be performed.

The effects of different pre-mixtures in nutrition of sows and piglets

In the last ten years we have been witnesses to import of numerous premixes produced by various producers and of different quality in regard to concentration of ingredients which are their main components. There is relatively few data on the effects of their nutritive value in pigs, so this research was carried out with objective to verify the effects of several different imported premixes and those produced according to domestic concept, in nutrition of sows, suckling piglets and weaned piglets. Research was performed on private farm in the vicinity of Sabac in Serbia. Obtained results showed that there was no significant difference in losses of body masses and food consumption in sows during lactation period. Nutrition of suckling piglets using mixture which contained adequate premix of domestic production improved the growth rate by 7.6%. Cost of food when domestic premixes were used in nutrition of sows and piglets was by 5.3% lower, and value of realized piglets by approx. 26.0% more favourable when domestic premixes were used in nutrition of sows and suckling piglets. Piglets in rearing were fed mixtures containing imported premixes showed no significantly important effect on gain, but had poorer feed conversion by 6.2% compared to animals fed diets containing domestic premix. Domestic premix in mixtures reduced the cost of mixtures by 3.4% and reduced the cost of gain of piglets in rearing by 9.9% compared to nutrition with diets containing imported premixes. In general, obtained results shoed that use of both types of compared premixes can be recommended, but it is more economically efficient to use domestic premixes in nutrition of sows and piglets.

Nutritional Composition of Frozen Fillets from Pangasius Catfish (Pangasius hypophthalmus) and Nile Tilapia (Oreochromis nilotcus) Imported to European Countries

Abstract The proximate composition, fatty acids and amino acids profile as well as mineral composition of frozen fillets from Pangasius catfish (Pangasius hypophthalmus) imported to Poland (PP), Germany (PG) and Ukraine (PU) and fillets from Nile tilapia (Oreochromis nilotcus) imported to Poland (TP) and Germany (TG) were investigated. PU contained ten times more fat than PG and PP. Tilapia fillets contained higher levels of n-3 fatty acids and showed more preferable n-6/n-3 ratio than pangasius fillets. The fillets of PG contained higher levels of protein and essential amino acids than PU and PP, however the amino acids composition of pangasius and tilapia fillets was similar for all specimens. The fillets of PP and PU contained significantly higher amounts of sodium than other studied groups, which suggests that they were subjected to additional treatment to increase their water holding capacity. The results show significant differences in the nutritional composition of pangasius depending on their place of import, thus it was recommended that more information regarding the nutritional composition of the frozen fillets sold through self-service freezers should be provided for the final consumer.