Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Novel technology to preserve nutrients in fruits: microbiota modulation by avocado fatty alcohols (AFAs) and derivatives(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06) Sánchez Rodríguez, Diana; Hernández Brenes, Carmen; emipsanchez; Pacheco Moscoa, Adriana; School of Engineering and Sciences; Campus Monterrey; Mora Godínez, Shirley MaríaAccess to safe food and reduction of postharvest losses in fruits and vegetables are crucial to address global hunger and nutritional deficiencies. Avocado (Persea americana var. Hass) is an economically significant crop in Mexico, but its quality and shelf-life are severely affected by microbial spoilage, accelerated ripening, and associated physiological disorders such as anthracnose. This study aimed to evaluate avocado fatty alcohols (AFAs) and derivatives as active antimicrobial components in natural coatings to modulate avocado microbiota and preserve avocado quality during simulated export conditions (cold storage at 4°C and ripening stage at 25°C). Two concentrations of AFAs (7,000 ppm and 14,000 ppm) were tested and compared to excipient coating (propylene glycol and avocado oil) and uncoated controls. Fruit quality was assessed through colorimetric parameters (lightness, chroma, and hue), respiration rate, firmness, and quantification of gray area in mesocarp. Avocado microbiota was characterized by metagenomic sequencing of the regions V3-V4 of the 16S rRNA for bacteria and ITS1 for fungi. Results showed that AFA and excipient coatings maintained avocado quality compared to uncoated fruits, preserving higher values of firmness, lightness, and chroma, and displaying lower total color differences, respiration rate, and weight loss in ripe avocados. Uncoated avocados exhibited higher percentage of gray areas in the mesocarp, higher respiration rates, and lower firmness than coated avocados. Regarding microbial diversity, coatings influenced bacterial and fungal communities. While beneficial bacteria such as Methylobacterium remained unaffected and a protective effect of AFAs against Proteobacteria was observed, spoilage-associated Firmicutes increased in AFA-coated and excipient samples. For fungi, coatings modulated populations from phytopathogenic taxa such as the Ascomycota phylum, the Cladosporiaceae family, and Colletotrichum spp. Avocado fatty alcohol-based coatings effectively maintained physicochemical quality compared to uncoated avocados and modulated some fungal communities. However, the differential effects between AFA and excipient coatings were less pronounced, highlighting the need for further validation to clearly define the specific antimicrobial and protective benefits of AFAs. This research provides foundational insights supporting the potential application of coatings in sustainable, natural fruit preservation technologies.
- Obtention of highly functional dietary fiber from avocado by-products using ultrasound(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-07-15) Valencia Espinosa, Illeen Marian; Garcia Amézquita, Luis Eduardo; puelquio, emipsanchez; Tejada Ortigoza, Viridiana Alejandra; Rodríguez Martínez, Verónica; Carrillo Nieves, Danay; Escuela de Ingeniería y Ciencias; Campus Monterrey; García Cayuela, TomásAvocado by-products generated in the oil extraction process represent a potential source of bioactive compounds with associated technological functionality in food formulations. The first by-product is the defatted pulp (BBP) from which a freeze-dried powder was obtained to determine its composition (AOAC methodologies): moisture (80.5 ± 0.0 g/100 g in wet basis.), protein (8.7 ± 0.2 g/100 g dry basis), ash (4.3 ± 0.3 g/100 g d.b), fat (10.3 ± 0.1 g/100g d.b.), SDFP (3.0 ± 0.2 g/100 g d.b.), IDF (62.3 ± 2.0 g/100 g d.b.), TDF, and DC (11.4 g/100g d.b.). Ultrasound-assisted extraction is an emerging technology used as a green alternative for extracting compounds of interest while reducing processing times, energy, and solvents. Sonication was applied to BBP and raw avocado pulp powder (PP) samples to determine their recovery yields and to evaluate the effect of two parameters: SLR (solid-liquid ratio 1:35 and 1:50) and pH (2 and 3). Low pH and SLR 1:50 resulted in a maximum SDFP recovery yield of 39.2 ± 1.2% for sample PP. Avocado seeds, peels, and a small fraction of pulp adhered to these comprise the other studied by-product (CSP). It contains high amount of water (95.1 ± 0.0 g/100 g w.b.), as well as the following compounds (g/100 g d.b.): 3.7 ± 0.4 of protein, 2.1 ± 0.3 ashes, 25.5 ± 0.7 of lipids, 57.1 ± 1.2 TDF (9.0 ± 0.3 SDFP and 48.1 ± 0.4 IDF), and 11.6 ± 0.5 digestible carbohydrates. This sample was used as a control for comparison after ultrasound treatment (USCSP). There was a significant difference (p < 0.05) in tapping density, swelling capacity, and oil retention capacity. Water retention capacity, solubility, viscosity, and minimum gelling concentration were also measured. Finally, antioxidant capacities for PP, BBP, CSP, and USCSP were determined by DPPH, with lower results than ABTS (2.53 ± 0.30, 4.22 ± 0.20, 13.46 ± 1.24, and 7.84 mg AAE/g d.b., respectively) assays. TPC was also determined by Folin-Ciocalteu assay (1.65 ± 1.4, 1.25 ± 0.2, 7.33 ± 1.02, and 4.41 ± 0.23 mg GAE/ g d.b., respectively); significant differences were observed. It was possible to obtain dietary fiber concentrates (TDF > 50% of their composition) with associated technological properties of interest for food industries.
- High intensity ultrasound processing effect on avocado and soybean oleogels(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-06) Rumayor Escobar, Andrés; Tejada Ortigoza, Viridiana Alejandra; puemcuervo; de la Rosa Millán, Julián; Morales de la Peña, Mariana; Arredondo Ochoa, Teresita; School of Engineering and Sciences; Campus Querétaro; Dibildox Alvarado, ElenaHigh Intensity Ultrasound (HIU) has been used to change crystalline networks of oleogels. The effect of HIU on structure and stability of soybean and avocado oleogels was evaluated. HIU treatments (25 and 50 % amplitude and 15 and 30 s) were applied at controlled 58°C to oleogels (first crystal appearance). All samples were analyzed by crystal morphology, melting behavior, solid fat content (SFC), texture, oil binding capacity (OBC) and viscoelasticity (G’ and G’’). Results showed that HIU reduced crystals size and from needle to a spherulite morphology for all treatments compared to control samples. Melting profile was similar (in shape) for all samples, but HIU samples calorimetry presented narrower peaks compared to controls. The lowest enthalpy values were presented in control samples, due to a smaller number of crystals and enthalpy was not modified among treatments. OBC in soybean samples increased significantly as treatments time and amplitude increased. In avocado oleogels, adhesiveness and OBC increased for the lowest amplitude treatment. HIU treatments increased firmness of all samples in contrast to control. Results showed that HIU can modify oleogels’ microstructure, forming smaller and more crystals than control samples. This formation of smaller crystals increased firmness, adhesiveness and OBC. Viscoelastic behavior was reduced in all HIU treatments for both oils (except A2, which increased) and SFC was reduced as the HIU treatment intensity increased for both matrices.