Hoje tem estreia no nosso blog! A Hora do Artigo traz as últimas publicações, artigos históricos e importantes de nossos pesquisadores do LADETEC. Nos orgulhamos de toda a produção científica que diariamente é realizada dentro de cada sala e nesse espaço vamos exaltar os resultados de todo ensino, pesquisa e extensão.
Prontos para começar?
O primeiro artigo é do Laboratório de Metabolômica – LabMeta. Foi publicado na revista Phytochemistry Letters com o título “Chemical profiling of herbarium samples of solanum (Solanaceae) using
Herbarium collections are broadly available for scientific evaluations but surprisingly few studies explored their rich chemical diversity. Considering the systematic organization and the storage conditions Herbarium collections are kept, we wonder if there are still secondary metabolites of interest after years of storage and how this data could be used to discriminate different species within the same genus. Thus, using a set of 25 Solanum (Solanaceae) samples selected randomly from the RFA Herbarium we designed a fast method to extract and analyze them using LC-HRMS/MS. This pilot study shows the broad chemical space of samples stored in Herbarium collections. Also, we performed multivariate analysis (PCA and PLS-DA) using data from two species, S. argenteum and S. pseudoquina, to evaluate if we could discriminate them based on their chemical profiles and we successfully showed sample grouping despite even 10 years of difference between their collection and their different collection sites. Thus, herbarium exsiccates was proven to be a reliable source of samples for NP chemistry studies. By this means, we make a plea in favor of the use of chemical profiling as a tool for taxonomists in collaboration with chemists for classification studies and to consider keeping an extract collection along with the exsiccates.
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Nosso segundo artigo do dia é do Núcleo de Análises de Alimentos – NAL. Foi publicado na revista Scientific Reports da Nature com o título “Combined efect of oxygenscavenger packaging and UV-C radiation on shelf life of refrigerated tilapia (Oreochromis niloticus) fllets”.
This study investigated the physicochemical, instrumental and bacterial parameters of tilapia fillets subjected to oxygen-scavenger packaging, alone or in combination with UV-C radiation at two doses (0.102 and 0.301 J/cm2), stored at 4 ± 1 °C for 23 days. The oxygen scavenger, both UV-C doses, and the oxygen scavenger combined with UV-C, independently of the dose, extended the shelf life in 5, 6 and 7 days, respectively, by decreasing the bacterial growth rate and the formation of degradation compounds (e.g., TVB-N and ammonia). Oxygen-scavenger packaging, alone or in combination with UV-C at 0.102 J/cm2 and 0.301 J/cm2 showed lower amounts of free amino acids (FAA; 34.39, 34.49 and 34.50 mg L-lysine/kg fish tissue, 3.63, 3.57 and 3.61 mg L- ornithine/kg fish tissue, 27.52, 27.63 and 27.67 mg L-arginine/kg fish tissue), biogenic amines (BA; 3.81, 3.87 and 3.89 mg cadaverine/kg fish tissue, 12.88, 12.91 and 12.86 mg putrescine/kg fish tissue, 2.41, 2.44 and 2.47 mg spermidine/kg fish tissue), redness (2.53, 2.55 and 2.59), yellowness (6.65, 6.69 and 6.72), lipid oxidation (1.52, 1.53 and 1.58 mg malondialdehyde/kg fish tissue) and protein oxidation (5.06, 5.11 and 5.18 nmol carbonyls/mg protein), with higher hardness (3273.41, 2652.98 and 2687.57 g) than control (air packaging; 41.97 mg L-lysine/kg fish tissue, 4.83 mg L- ornithine/kg fish tissue, 37.33 mg L-arginine/kg fish tissue, 4.82 mg cadaverine/kg fish tissue, 16.56 mg putrescine/kg fish tissue, 3.21 mg spermidine/kg fish tissue, 4.26 of redness, 8.17 of yellowness, 2.88 mg malondialdehyde/kg fish tissue, 9.44 nmol carbonyls/mg protein and 2092.58 g of hardness), respectively, on day 13 of storage when the control fillets were unfit for consumption (7 log CFU/g) (p < 0.05). However, in the same day of storage, both UV-C doses had similar values for BA (p > 0.05), higher amounts of FAA (44.28 and 44.13 mg L-lysine/kg fish tissue, 5.16 and 5.12 mg L- ornithine/kg fish tissue, 40.20 and 40.28 mg L-arginine/kg fish tissue), redness (4.86 and 5.33), yellowness (9.32 and 10.01), lipid oxidation (3.09 and 3.52 mg malondialdehyde/kg fish tissue) and protein oxidation (10.27 and 11.93 nmol carbonyls/mg protein), as well as lower hardness (1877.54 and 1767.39 g), respectively, than control fillets (p < 0.05). The combined preservation methods were the most effective in extending the shelf life and prolonging the physicochemical quality of the refrigerated tilapia fillets and the O2 scavenger proved to be a potential alternative to prevent the negative changes induced by both UV-C doses.
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