Effect of heat treatments on the physicochemical and sensory properties of the longissimus thoracis muscle in unweaned Limousin calves

The aim of the study was to assess the effect of methods of heat treatment on selected quality parameters of longissimus thoracis muscle of Limousin calves, subjected to grilling, steaming, and sous vide cooking. The type of heat treatment did not significantly affect shear force or water activity. Cooking loss in the grilled and steamed meat was significantly higher than in the sous vide. While the content of vitamin E was significantly lower in the cooked meat, it was retained to the greatest degree in the grilled meat and least in the steamed meat. The TBARS index significantly increased during all cooking methods with the highest level in steamed meat. The sensory analysis revealed a preference for the sous vide and grilled meat, while the steamed meat received the lowest scores. Although veal is commonly assumed to be highly nutritious and palatable, its quality can be significantly influenced by the type of heat treatment.

Fatty acid profile and health lipid indicies of goose meat in relation to various types of heat treatment

The effect of water bath cooking (WBC), oven convection roasting (OCR), grilling (G), pan-frying (PF) on the fatty acid profile and health lipid indices of goose meat was investigated in this study. The experimental material covered 80 breast muscles (40 with skin and subcutaneous fat and 40 without skin) cut from carcasses of 17-week-old "Polish oat geese". The fatty acid profile of meat was determined by gas chromatography and health lipid indices were calculated. It was stated that the kind of heat treatment as well as the type of goose meat (muscles with and without skin) affected the fatty acid profile and health lipid indices. The sum of SFA was significantly higher in cooked samples for both kinds of meat than in raw ones. The cooked samples with skin had a lower increase in Ʃ SFA than the skinless meat. Boiling (meat without skin) and pan-frying (both kinds of meat) caused a slight decrease, while grilling and oven convection roasting (both kinds of meat) caused an increase of Ʃ MUFA in comparison to raw samples. Moreover, meat with skin is characterized by a higher value of Ʃ MUFA than meat without skin for all cooking methods. The Ʃ PUFA was lower in all cooked samples than in raw meat, wherein this decline was usually higher for skinned meat. The G meat was the lowest and PF the highest in Σ PUFA for both kinds of meat after heat treatment. The highest loss showed C20:4 n-6 in OCR samples and the lowest C18:2 n-6 in PF (both kinds of meat). Heat treatment caused an increase in the Σ PUFA n-6/n-3 ratio, wherein the lowest value was shown by the WBC samples without skin, and the highest by OCR with skin. Water bath cooking of meat was more beneficial for consumers in terms of AI, TI, Σ DFA/Σ OFA, Σ PUFA/Σ SFA, Σ UFA/Σ SFA indexes and Σ SFA, Σ OFA values than the remaining methods.

Effect of low-pressure plasma treatment on the color and oxidative stability of raw pork during refrigerated storage

The effect of low-pressure plasma on quality attributes of meat is an important aspect, which must be considered before application in food. The aim of this study was to determine the color, fatty acid composition, lipid oxidation expressed as thiobarbituric acid reactive substances and total antioxidant capacity of raw pork samples exposed to helium low-pressure plasma treatment (20 kPa) for 0, 2, 5, and 10 min during the storage period. The thiobarbituric acid reactive substance concentrations of all plasma-treated samples during storage were in the range from 0.26 to 0.61 mg malondialdehyde/kg. Exposure time caused significant changes only in total color difference, hue angle, and chroma after 10 min of treatment. Ferric reducing ability of plasma values of meat samples decreased from 1.93 to 1.40 mmol Trolox Eq/kg after 14 days of storage. The storage period significantly affected proportion of polyunsaturated fatty acids, with an increase about 3% after 14 days of refrigeration storage while the content of saturated fatty acids was at the same level. Helium low-pressure plasma does not induce oxidative processes. Application of this decontamination technique while maintaining product quality is possible in food industry.

Effect of dietary nutrient density and vitamin premix withdrawal on performance and meat quality of broiler chickens

BACKGROUND

The objective of this study was to evaluate the effects of feeding high- and low nutrient density diets, and three different vitamin premix withdrawal regimes on broiler performance and meat quality. Male broiler chicks (480 days old) were reared on the floor in a 2 × 3 factorial arrangement for 42 days. Chickens were slaughtered at 42 days of age and meat samples kept at -20 ± 1°C and analysed after 1, 90 and 180 days of storage.

RESULTS

Broiler performance was significantly affected by dietary nutrient density. Vitamin premix withdrawal had no significant effect on body weight. The results showed no significant differences between nutrient density and vitamin premix withdrawal on lightness (L*), redness (a*) and yellowness (b*). Oxidative stability of thigh muscle lipids during frozen storage was significantly affected by nutrient density, while vitamin premix withdrawal had no significant impact on lipid oxidation. High nutrient density diet led to a significantly (P < 0.05) decreased pH compared with the low nutrient density diet.

CONCLUSION

Increasing dietary nutrient density improved broiler performance but impaired meat quality while vitamin premix withdrawal during finisher periods had no negative effect on broiler performance and meat quality.

Effect of dietary n-3 and n-6 PUFA on lipid composition of different tissues of German Holstein bulls and the fate of bioactive fatty acids during processing

The present study investigated the effects of dietary linolenic acid (ALA) versus linoleic acid (LA) on meat quality, fatty acid composition, and stearoyl-CoA desaturase (SCD) activity in longissimus muscle (MLD) and subcutaneous adipose tissue (SAT) of German Holstein bulls and the transfer of beneficial n-3 fatty acids into German corned beef sausages (GCB). Feeding LA- and ALA-enriched diets increased essential fatty acids in MLD and SAT. The ALA-supplemented diet decreased significantly the SCD activity in MLD and SAT, resulting in a reduced relative concentration of oleic acid in muscle. The relative proportion of CLAcis-9,trans-11 analyzed by HPLC was not different between groups in either tissue. GCB were produced by using the lean meat of bulls. Beef products of bulls fed the ALA-supplemented diet were rich in ALA and n-3 LC PUFA. Most importantly, there was no loss of n-3 fatty acids during processing under production conditions. Conclusively, the n-6/n-3 fatty acid ratio was beneficially low.