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The present study aimed to test the effect of a dietary supplementation with Silybum marianum (SM), an herbaceous Mediterranean plant traditionally used to treat liver and gastrointestinal diseases and with antioxidant properties, on the productive performance, carcass traits and meat quality of growing rabbits. With this purpose, at weaning (5 weeks of age), a total of 144 Pannon Large rabbits were allocated to three experimental groups. The control group (C, n=51) was fed with a basal diet, whereas the other groups received the basal diet supplemented with SM herbal powder at two concentrations: 5 g/kg (SM1, n=48) and 10 g/kg (SM2, n=45). Rabbits were housed in wire-mesh cages (3 rabbits/cage) and fed ad libitum throughout the experiment. Productive performance and mortality were recorded weekly. Rabbits were slaughtered at 11 weeks of age, carcasses were dissected, and hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were analysed for meat quality (oxidative status, pHu and L*, a*, b* colour) traits. In addition, a sensory analysis on the LTL meat was carried out by a trained panel. Mortality was significantly reduced in SM treatments compared to C group from week 6–7 (10.4 and 11.1 vs. 17.7%, for SM1, SM2 and C groups, respectively; P

The European ban on the non-therapeutic use of antibiotic growth promoters and limits on the use of other drugs have increased digestive disorders and mortality in growing rabbits. In addition, consumers demand natural products, and therefore synthetic active compounds should be replaced by natural ones. This has increased the search for alternatives, such as herbs, spices and their extracts (botanicals) as replacers. Plants (whole plants, leaves or seeds, mainly used as feedstuffs) and their extracts (considered as additives) are being increasingly used in animal nutrition as appetisers, digestive and physiological stimulants, colorants, and antioxidants, and for the prevention and treatment of certain pathological conditions. The digestive effects of herbs and spices have been tested primarily in humans and laboratory animals, and few trials have been performed on farm animals. Studies on the dietary inclusion of herbs and spices or their extracts in rabbit meat production are quite scarce, and the overall benefit remains unclear due to discrepancies in results, such as the use of plant preparations as galactagogues in rabbit does. Some positive results have been shown their potential, however. The dietary inclusion of Foeniculum vulgare Mill. seeds with oregano leaves has been observed to improve diet utilisation, whereas the dietary inclusion of a mixture of Lupinus albus L., Trigonella foenum-graecum L., and Cassia senna L. has acted as growth promoter. Antimicrobial effects are derived especially from plant volatile oils. In the rabbit, a stabilizing effect on microbiota was observed when the diet was supplemented with thyme oil. When diets were supplemented with thyme leaves and spirulina algae, an antimicrobial effect on Clostridium coccoides, Clostridium leptum in the caecum was observed. Black cumin seeds have been shown to exert anti-inflammatory, anti-bacterial and immunomodulatory effects. Several herbs and spices (green tea, rooibos, oregano, rosemary and thyme) provide antioxidant effects through rabbit dietary supplementation or inclusion in meat and meat products. Research in the use of herbs or/and spices has demonstrated their potential as feed additives and/or antioxidants, but further research is recommended to optimize effects on rabbits before practical proposals can be drafted.

The present study tested the effect of a liquorice root extract (L) administration in the diet of growing rabbits and/or in their minced meat. A total of fifty-six rabbit does and their kits (3 weeks of age) were divided into 4 groups receiving a commercial diet (C) or the C diet supplemented with increasing levels of L: 2 g/kg (L2), 4 g/kg (L4), 6 g/kg (L6). At weaning (5 weeks of age), sixty rabbits/group were randomly selected, caged by 3, and fed ad libitum with the experimental diets until slaughter (12 weeks of age). At 6 weeks of age, 6 rabbits/diet were selected for gastrointestinal tract pH and caecal microbial count analyses. Live performance and health status were recorded weekly and daily, respectively. Carcass traits were measured after slaughter and hind leg (HL) and Longissimus lumborum (LL) meat were dissected for pHu and L*a*b* colour measurements. Minced meat from HL belonging to C and L6 dietary treatments was each split in two parts to incorporate liquorice extract at 0.25% (w/w), obtaining four groups of meat burgers: CC; CL; L6C and L6L. The pH, L*a*b* colour and microbial count (TVC, Coliforms, and Pseudomonas) were measured at days 0, 3 and 6 of refrigerated storage. A sensory analysis was conducted on LL meat of C and L6 dietary treatments, and tested attributes were odour, taste, flavour, texture and off-flavours. Liquorice dietary inclusion did not show a clear effect on live performance, resulting comparable among groups, with exception of the lowest growth rate for L2 rabbits (P

Pseudomonas cepacea lipase (PCL) was used to catalyse the transesterification reaction between 1-phenylethanol and vinyl acetate in supercritical carbon dioxide (SCCO2). The enzyme, which is very selective towards one of the isomers of 1-phenylethanol, was very stable in the supercritical medium and showed higher reaction rates. The effect of SCCO2 pressure on the catalytic efficiency of PCL at a constant temperature was evaluated. With increasing pressure of the reaction medium the catalytic efficiency of the enzyme considered improved resulting in negative activation volume (−1340 cm3/mol) approaching critical values. A study of the kinetic mechanism in the SCCO2 reaction medium was also performed. Moreover supercritical sulphur hexafluoride (SCSF6) was used as reaction medium as a point of comparison with SCCO2. Preliminar data showed high stability of the enzyme in this supercritical medium and kinetic curve reported point out increased reaction rates in comparison to those achieved in SCCO2.

Candida rugosa lipase (CRL) shows high enantioselectivity toward (1 R ,2 S )-(−)- trans -2-phenyl-1-cyclohexanol enantiomer in acetylation reaction employing vinyl acetate as acyl donor. Attempts to improve reaction yields have pointed out that supercritical CO 2 is the best reaction medium in the studied biocatalytic process. In these conditions an immobilised lipase from Candida rugosa is able to quantitatively resolve racemate with e.e. p 100%.