No abstract

The objective of the work is to perform the partial chemical characterization of the liver oil pool of shark species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis captured in the north central coast of Cuba and extracted at 50° C for 20 min. Parameters are determined such as the acid value, refractive value, relative density, saponification value, content of insoluble impurities in n-hexane, anisidina value, peroxide value and the UV-Vis spectrum, where it is shown that the oil is suitable for consumption provided that the sampling is carried out inside the liver sample. Shown that the oil extracted under these conditions meets the quality parameters required for its use.

Context: The shark liver of the species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, captured in the north-central coast of Cuba are a source of oil, whose content of major fatty acids could be used in its quality control. Aims: To develop a simple and robust gas chromatography with a flame ionization detector (GC-FID) method that is suitable for routine analysis of four major fatty acids extracted shark liver oil. Methods: Four major fatty acid content in shark liver oil pool of species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, was analyzed through the gas chromatography with a GC-FID. The fatty acids were analyzed as methyl esters derivatives, using 5% aqueous sulfuric acid in methanol. The method was validated in terms of linearity, precision, accuracy, specificity and limit of detection and quantitation. Results: Under the optimum analytical conditions, the analysis revealed that each target component was well separated with satisfactory recoveries and reproducibility. The method linearity was found to be high with good determination coefficient values for all target components. The evaluation of the matrix effect, demonstrated, that there is not interference from substances other than analysis. The method was also found to be accurate, precise and reproducible and it was applied to the quantitative determination of the fatty acid content in shark liver oil pool; oleic acid was the most abundant fatty acid (22.69%), followed by palmitic (18.85%), stearic (6.01 %) and myristic acid (0.40 %). Conclusions: The GC-FID developed method is reliable and suitable for determination of four major fatty acids in shark liver oil pool.

Common bean (Phaseolus vulgaris L.) is an important grain legume cultivated worldwide as food for humans and livestock (Schwartz et al., 2005). Common beans in central Chile reach up to 3,893 ha from which 1,069 ha are located in the Maule region. Common bean is produced by small farmers who have limited access to fertilization, technical irrigation, and crop protection. In spring 2018, bean plants initially showed a slight yellowing and premature senescence 50 days after sowing (das) until showing wilting symptoms (70 -100 das) in Curepto fields (35 05'S; 72 01'W), Maule region. The basal part of affected plants displayed internal reddish-brown discoloration of the vascular tissues. Based on the plant external symptoms, we estimated an incidence between 15% and 45% in bean fields. Nine symptomatic plants were collected, and surface washed with sterile water and disinfested with 75% ethanol (v/v). Then small fragments (5-mm) from damage vascular tissue from each plant were cut and placed on Petri dishes containing PDA acidified with 0.5 ml/l of 92% lactic acid (APDA, 2%). The isolations were incubated for seven days at 25°C. Nine Fusarium-like isolates from single-spore on APDA (2%) became pale vinaceous, floccose with abundant aerial mycelium and dark vinaceous reverse colony, with a growing rate of 10.8 to 11.6 mm/d at 25°C (Lombard et al., 2019). Phialides were short, singular growing laterally on the mycelium. Macroconidia were hyaline, fusiform with basal foot cells shaped to pointed and apical cells tapered, 2-5 septate, and 28.6 to 47.6 (av. 38.1) μm long x 2.2 to 3.6 (av. 3.1) μm wide. Microconidia were hyaline, oval to ellipsoid, one-celled, and 4.5 to 10.9 (av. 6.1) μm long and 2.2 to 3.3 (av. 2.7) μm wide (n=50 spore). For molecular identification, three isolates (Curi-3.1, Be-8.1, and Be-11.3) were sequenced using PCR amplification of the partial sequences of beta-tubulin (BT) and translation elongation factor 1-α gene (TEF) (Lombard et al., 2019). NCBI BLAST analysis showed 99 to 100% similarity with sequences (TEF; BT) of strain CPC 25822 of Fusarium oxysporum. The maximum-likelihood phylogenetic analysis placed the Chilean isolates in the F. oxysporum complex clade. Chilean sequences were deposited into GenBank under accession numbers MW419125, MW419126, MW419127 (TEF) and MW419128, MW419129, MW419130 (BT). Pathogenicity tests (isolates Curi-3.1, Be-8.1, and Be-11.3) were conducted under greenhouse (15-28°C, 85%RH) on healthy bean plants (n=30) cv. Blanco Español INIA cultivated in pots (sand/peat moss/soil) at the University of Talca. Plants that are 30 days-old were inoculated using 200 μl of conidial suspension (106 conidia/ml) on wounded roots (crown). Control plants (n=10) were similarly inoculated with sterile distilled water. After 45 days, all inoculated plants with F. oxysporum isolates developed necrotic lesions on vascular tissue, and chlorosis, and wilting while control plants remained healthy. This experiment was conducted twice. The pathogen was reisolated (100%) from diseased plants and molecularly identified as F. oxysporum. To our knowledge, this is the report of a severe outbreak of F. oxysporum causing Fusarium yellows in P. vulgaris in the Maule region, Chile. Previously, F. oxysporum has been reported affecting tomato (Sepúlveda-Chavera et al., 2014) and blueberry in Chile (Moya-Elizondo et al., 2019).

The aim of this study is to evaluate the survival rate and effective antagonistic activity against Botrytis cinerea, responsible for grey mould on harvested fruits and vegetables, of yeast Rhodotorula mucilaginosa, isolated and identified from the natural microbiota of murta (Chilean guava) berries, after spray drying at different inlet air temperatures, mass per volume ratio of encapsulating agent (maltodextrin) and feed flow rates. The 100 % survival of the yeast was obtained after spray drying with 18 % maltodextrin at 130 °C inlet temperature and a feed flow rate of 9.25 mL/min. The dried yeast obtained under such conditions had the highest antagonistic activity in vitro and in vivo on apples, which showed that spray drying is a valid method to produce active dried cells of R. mucilaginosa that can be used for biocontrol of grey mould spoilage. It was also found that the encapsulating agent maltodextrin improved the in vitro antagonistic activity of R. mucilaginosa.