No abstract

The use of whole citrus fruits in the food industry means that the valuable peel is used, but this may raise palatability or health concerns among consumers. The content of sugars, dietary fibre, redox compounds, lead, and cadmium was compared in citrus fruits (orange; pomelo; mandarin; lemon; key lime; and red, yellow, and green grapefruit). The pulp of all fruits contained significantly less fibre, tannins, and phenolic compounds than the peel. Whole citrus fruits had significantly lower content of sugars and higher content of dietary fibre and phenolic compounds, including ferulic acid, than their pulps. Whole grapefruits had higher concentrations of ascorbic acid. Whole lemons, limes, and mandarins had higher antioxidant potential than their pulp, due to their higher content of ascorbic acid, tannins, and phenolic compounds. Lead and cadmium content in whole fruits, while higher than in the pulps, was well below the acceptable daily intake.

The aim of the study was to determine the content of macrominerals and microminerals in the longissimus lumborum (LL) and semitendinosus (ST) muscles of young bulls of five breeds—Polish Red (PR), White-Backed (WB), Polish Black-and-White (PBW), Simmental (SIM) and Polish Holstein-Friesian (PHF). The meat of the Polish Holstein-Friesian bulls was found to contain significantly less K, Mg and Ca and more Mn than other breeds. The meat of the White-Backed bulls contained significantly (P < 0.01) more Ca and less Na than the meat of the Polish Red, Simmental and Polish Holstein-Friesian breeds. Moreover, the meat of White-Backed bulls showed a significantly (P < 0.01) higher level of Mn and Cu in comparison with other native breeds (Polish Red and Polish Black-and-White) and the Simmental breed. Similar content of macronutrients was found in the LL and ST muscles. However, in the case of micronutrients, the LL muscle contained significantly more Zn, Fe and Cu as well as Mn (P > 0.05).

No abstract

The aim of the experiment was to assess the effect of dietary alpha-ketoglutarate (AKG) supplementation on performance, serum hormonal indices, duodenum and jejunum histomorphometry, meat quality characteristics, bone quality traits and cartilage degradation in laying hens with a mature skeletal system. Forty-eight 30 week-old Bovans Brown laying hens were randomly assigned to a control group or the group fed the basal diet plus 1.0% AKG. The experimental trial lasted 30 weeks. The supplementation of AKG increases blood serum content of leptin, ghrelin, bone alkaline phosphatate and receptor activator of nuclear factor kappa-Β ligand, while osteoprotegerin and osteocalcin decrease. While dietary AKG was given to laying hens negatively influenced villus length, crypt depth, villus/crypt ratio and absorptive surface area in duodenum and jejunum, these changes have no effect on feed intake, weight gain, nor laying performance. In breast muscles, no significant changes in skeletal muscle fatty acid composition were observed, however, a higher shear force and decreased cholesterol content following AKG supplementation were noted, showing the improvement of muscle quality. While dietary AKG supplementation did not affect the general geometric and mechanical properties of the tibia, it increased collagen synthesis and enhanced immature collagen content. In medullary bone, an increase of bone volume fraction, trabecular thickness, fractal dimension and decrease of trabecular space were observed in AKG supplemented group. The trabeculae in bone metaphysis were also significantly thicker after AKG supplementation. AKG promoted fibrillogenesis in articular cartilage, as indicated by increased cartilage oligomeric matrix protein immunoexpression. By improving the structure and maintaining the proper bone turnover rate of highly reactive and metabolically active medullar and trabecular bones AKG showed its anti-osteoporotic action in laying hens.

Young slaughter cattle are primarily fattened to produce culinary beef. Its final quality is determined by a broad spectrum of factors, including pre-slaughter factors (such as type, breed, sex, feeding system) and post-slaughter factors (such as dressing and meat ageing) (Kołczak, 2008; Litwińczuk and Litwińczuk, 1998; Miciński et al., 2005). It is assumed that the best quality meat is obtained from young animals of the beef type up to 2 years of age.

No abstract

The aim of this study was the evaluation of the insect processed animal protein (IPAP) contamination level by Clostridium spp. Particularly, we screened for the occurrence of pathogenic species of Clostridia. The samples of IPAP were derived from yellow mealworm (Tenebrio molitor) and black soldier fly (Hermetia illucens) available in the Polish market. The IPAPs were added to experimental feeds for poultry. The differences between the contamination levels of the control (without the addition of IPAP) and experimental (with the addition of IPAP) groups were monitored. The samples were also examined by culture and PCR-based methods to detect 16S rDNA and genes determining botulinum toxin (BoNT) production. Statistical significance was noticed among the feed with the IPAP addition, as well as an increase of contamination by Clostridium spp. In one sample of IPAP, the occurrence of ntnh and bont/D genes determining the production of BoNT/D was noticed. However, a positive result was noticed only at the step of the liquid culture; the Clostridium botulinum type D strain was not isolated. Phenotypically, and according to the 16S rDNA analysis, genetically similar strains to C. botulinum species were isolated. Considering the microbiological safety of IPAP and expanding possibility of its use in livestock animal feed, it seems to be reasonable to provide complex risk assessment on the potential transfer of Clostridia into feed compounds, to assure the safety and sustainable development of insect PAP industry.