48 research outputs found
Rosemary distillation residues reduce lipid oxidation, increase alpha-tocopherol content and improve fatty acid profile of lamb meat
The experiment studied the effects of rosemary distillation residues (RR) intake on lamb meat quality, oxidative stability and fatty acid (FA) profile. Barbarine lambs of Control group were fed 600 g of hay, which was substituted by 600 g of pellets containing 60 and 87% of RR for RR60 and RR87 groups; all animals received 600 g of concentrate. Meat protein and fat content was similar for 3 treatments. Lipid oxidation was strongly reduced with RR diets. Both RR diets resulted in a higher a- tocopherol content in muscle. The metmyoglobin and deoxymyoglobin percentages were similar for all groups; however oxymyoglobin was higher for RR groups. The saturated (SFA) and unsaturated FAs (UFA) were unaffected by the diets. However, the PUFA, n-6 and n-3 were higher for RR groups. In conclusion, rosemary residues resulted in higher vitamin E content, so it enhanced the oxidative status and improved the fatty acid profile of lamb meat
Effects of salt stress on plant growth, abscisic acid and salicylic acid in own-rooted cultivars of Vitis vinifera L.
Aim of study: In most areas of vineyards worldwide, cultivars are frequently grafted on specific rootstocks to avoid Daktulosphaira vitifoliae pest attack. Nevertheless, the absence of this pest in Canary Islands allowed the chance to conserve and cultivate traditional or new own-rooted genotypes without the requirement of the rootstocks. To investigate the responses of own-rooted genotypes of Vitis vinifera L. to salt stress conditions, âCastellana Negraâ (âCNâ) and âNegramollâ (âNeâ) were used with the aim to characterize their morphological and physiological responses.Area of study: Canary Islands, Spain.Material and methods: The effects of NaCl stress on growth, abscisic acid (ABA), salicylic acid (SA) and proline were assessed in âCNâ and âNeâ under greenhouse conditions.Main results: In âCNâ, the decrease of leaf number in stressed plants was lower and started eleven days later than in âNeâ. Salt stress also reduced stomatal conductance (gs), although such decrease took place earlier in âCNâ than in âNeâ. ABA and SA concentrations in âCNâ leaves were 2-fold higher than those of âNeâ. Salt stress increased leaf ABA and SA content in both genotypes, compared to control. In conclusion, ABA and SA appear to be involved in grapevines responses to salinity and suggest that exogenous SA could be useful to mitigate the stress impacts.Research highlights: âCNâ exhibited a better response than âNeâ through the delay of salt injury establishment, and the dissimilar responses between âCNâ and âNeâ seem to be associated to the higher accumulation of ABA and SA under salt stress
Delay of early fruitlet abscission by branch girdling in citrus coincides with previous increases in carbohydrate and gibberellin concentrations
Current evidence in citrus indicates that gibberellins (GAs) are main determinants of early fruit set while subsequent growth of developing fruits is mostly dependent upon carbohydrate availability. In this work, branch girdling performed at anthesis in Satsuma mandarin (Citrus unshiu (Mak.) Marc.) cv. Okitsu transitorily reduced early abscission rates (12-32 days after anthesis, DAA) delaying initially the process of natural fruitlet drop. The effects of girdling on growth, gibberellin (GA) and carbohydrate concentrations in developing ovaries and fruitlets were assessed during this initial growth stage (0-69 DAA). In girdled branches, abscission rate reduction was preceded by elevated concentrations of carbohydrate and GA in developing ovaries and fruitlets. Girdling at anthesis stimulated higher hexose (21 DAA) and starch (6-20 DAA) concentrations and also higher GA(1) (6 DAA), GA(19) (13-20 DAA) and GA(20) (6-20 DAA). The results established a relationship between the reduction of early abscission rates and higher concentrations of carbohydrates and GAs induced by girdling in developing fruitlets. These findings revealed that girdling certainly increased GA concentration and strongly suggested that its effect on early fruitlet abscission delay is likely mediated by both GA and carbohydrates
Stock discrimination of two insular populations of Diplodus annularis (Actinopterygii: Perciformes: Sparidae) along the coast of Tunisia by analysis of otolith shape
Background. The annular seabream, Diplodus annularis (Linnaeus, 1758), is the most common sparid fish in the Mediterranean Sea. This species is widespread in Tunisia. Despite their economic importance, due to their excellent white and delicate flesh (demersal fish) and their significant size, few studies have hitherto focused on stock discrimination and on the fisheries management. The goal of this research was to evaluate the stock structure of D. annularis for two Tunisian insular populations based on the otolith shape, using different statistical approaches. Materials and methods. The specimens of Diplodus annularis were collected during five months ranging from May through September 2014 at two sites: Djerba and Kerkennah. In total, 120 fish were collected from the two study sites: 60 specimens of each population (30 males and 30 females) and were included in different statistical analyses. The Fourier coefficients were determined to evaluate the degree of similarity in the otoliths and detect the reciprocal variability. Results. By comparing the two studied populations, we revealed statistical significant differences, an asymmetry (leftâright), of otoliths (P < 0.05). In the same population, symmetry (leftâright) was detected for the males, females of Kerkennah, and females of Djerba. However, an asymmetry was detected only for the males of Djerba. Also, sexual dimorphism was observed only for the Djerba population. Conclusion. The comparison of the otolith morphology of the two populations showed a clear difference in shape and a leftâright asymmetry of otoliths. This asymmetry indicates that the two populations belong to different stock of fish. The stocks characterization is considered as an important tool for fisheries management. Further studies are necessary to determine the origin of the otolith shape differences and whether they are related only to environmental conditions or a genetic basis may also be responsible