Browsing by Author "Delgado Ospina, Johannes"
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Item Contaminación del aire: casos de investigación en el Valle del Cauca(Editorial Universidad Santiago de Cali, 2020-11-28) Cuervo Mulet, Raúl Alberto; Fernández Daza, Fabián Felipe; Balanta Galvis, Michel Fernanda; Delgado Ospina, Johannes; Guanga Esterilla, Leidy Maritza; Granada, Luis Felipe; González Vargas, Iván Andrés; López Villalobos, Iván Darío;Item Effect of pretreatment with low-frequency ultrasound on quality parameters in gulupa (Passiflora edulis sims) pulp(2021) Calderón Martínez, Vanessa; Delgado Ospina, Johannes; Ramírez Navas, Juan Sebastián; Flórez López, Edwin; Valdés Restrepo, Magda Piedad; Grande Tovar, Carlos David; Chaves López, ClemenciaThe Gulupa (Passiflora edulis f. edulis Sims) is an expression of South America’s tropics’ biodiversity, and a source of B vitamins and amino acids. It is a climacteric export fruit for which it is necessary to incorporate emerging technologies for its conservation and transport. This work investigated the effect of ultrasound on gulupa pulp and verified the stability of the characters of interest in the shelf life of 20 days. Six treatments and a control sample were used, evaluated in triplicate, and varied in frequency (30 and 40 kHz) with an exposure time of 10, 20, and 30 min. A statistical analysis of unidirectional variances and Dunnett’s test was used. It was found that the ultrasound treatments did not affect the pH or the titratable acidity. Soluble solid results presented a significant increase (p < 0.05) (from 13.4 to 14.8% w/v) in the antioxidant capacity (from 1.13 to 1.54 µmol Trolox Equivalent (TE)/g by the ABTS•+ (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) Cationic Radical Assay and from 3.3 to 3.7 µmol TE/g by the DPPH· (2,2-diphenyl-1-picrilhydrazil) Radical Scavenging Assay). During the shelf life, ascorbic acid was the parameter that varied most (p < 0.05). It decreased from 42.7 to 21.6 mg ascorbic acid/100 g of pulp in the control sample. However, a smaller decrease was observed (23.8–24.5 mg ascorbic acid/100 g of pulp) in the 40 kHz treatments. The smallest global color difference (∆E) for the control was found in the 40 kHz treatment at 30 min through the entire shelf life (day 0 to 20). Ultrasound treatment offers a new strategy to improve and extend the shelf life of chilled gulupa pulp.Item Evaluación de la actividad antimicrobiana y anti-biofilm de aceites esenciales de Zingiber officinale, Melaleuca alternifolia, Citrus aurantium dulcis y Eugenia caryophyllat frente a enterobacterias encontradas en el cacao(Universidad Santiago de Cali, 2023) Cruz Vega, Yuliana; Delgado Ospina, Johannes; González, Iván AndrésIn this study, the effect of essential oils of ginger (Zingiber officinale), tea tree (Melaleuca alternifolia), orange (Citrus aurantium dulcis) and clove (Eugenia caryophyllata) on twelve strains of Enterobacteriaceae removed from dried cocoa was investigated. clove and tea tree essential oils were able to inhibit all twelve strains of enterobacteria, at concentrations 1.25 mg/g to 0.625 mg/g and 5.0 mg/g to 2.5 mg/g respectively, while ginger oil alone it was effective against four strains at the highest concentration tested 20 mg/g. On the other hand, orange oil did not show inhibition capacity against any of the evaluated strains. Regarding biofilm formation, the effects of essential oils in Sub-MIC, MIC and Upper-MIC concentrations were evaluated, their action classified according to the percentage of inhibition as stimulating, low, moderate, high and excellent. In biofilm removal, the four essential oils showed significant activity, especially clove and tea tree oils showed better efficacy, preventing biofilm formation between 90% and 100% in enterobacteria, confocal laser scanning microscopy (CLSM) analyzes ) confirmed the results obtained in the inhibition of biofilm formation, especially in the strain Klebsiella pneumoniae spp. pneumoniae B001. In biofilm removal, significant results will be obtained with the use of clove oils, tea tree achieved high and excellent removals, while orange and ginger oil achieved high removals, orange oil presented better removal action. Biofilm compared to ginger oilItem Exploring the Core Microbiota of Four Different Traditional Fermented Beverages from the Colombian Andes(2022-12) Delgado Ospina, Johannes; Puerta Polanco, Luisa Fernanda; Grande Tovar, Carlos David; Cuervo, Raúl Alberto; Navia Porras, Diana Paola; Poveda Perdomo, Luis Gabriel; Fernández Daza, Fabián Felipe; Chaves López, ClemenciaFermentation is an ancient process used to prepare and preserve food. Currently, fermented beverages are part of the culture of people living in the Colombian Andean Region, and they are a vital part of their cosmology and ancestral vision. Chicha, Forcha, Champús, and Masato are some of the most common Colombian Andes region’s traditional fermented beverages. These drinks come from the fermentation of maize (Zea maize), but other cereals such as wheat or rye, could be used. The fermentation is carried out by a set of bacteria and yeasts that provide characteristic organoleptic properties of each beverage. In this work, the information collected from the metagenomics analyses by sequencing ITS 1-4 (Internal Transcriber Spacer) and the 16S ribosomal gene for fungi and the V3-V4 region of the rDNA for bacteria allowed us to identify the diversity present in these autochthonous fermented beverages made with maize. The sequencing analysis showed the presence of 39 bacterial and 20 fungal genera. In addition, we determined that only nine genera of bacteria and two genera of fungi affect the organoleptic properties of smell, colour, and flavour, given the production of compounds such as lactic acid, alcohol, and phenols, highlighting the critical role of these microorganisms. Our findings provide new insights into the core microbiota of these beverages, represented by Lactobacillus fermentum, Acetobacter pasteurianus, and Saccharomyces cerevisiae.