Browsing by Author "Campos, David"

Now showing 1 - 11 of 11
  • No Thumbnail Available
    Item
    A multiomics integrative analysis of color de-synchronization with softening of 'Hass' avocado fruit: A first insight into a complex physiological disorder
    (2023) Nunez-Lillo, Gerardo; Ponce, Excequel; Arancibia-Guerra, Camila; Carpentier, Sebastien; Carrasco-Pancorbo, Alegria; Olmo-Garcia, Lucia; Chirinos, Rosana; Campos, David; Campos-Vargas, Reinaldo; Meneses, Claudio; Pedreschi, Romina
    Exocarp color de-synchronization with softening of 'Hass' avocado is a relevant recurrent problem for the avocado supply chain. This study aimed to unravel the mechanisms driving this de-synchronization integrating omics datasets from avocado exocarp of different storage conditions and color phenotypes. In addition, we propose potential biomarkers to predict color synchronized/de-synchronized fruit. Integration of transcriptomics, proteomics and metabolomics and network analysis revealed eight transcription factors associated with differentially regulated genes between regular air (RA) and controlled atmosphere (CA) and twelve transcription factors related to avocado fruit color de-synchronization control in ready-to-eat stage. CA was positively correlated to auxins, ethylene, cytokinins and brassinosteroids-related genes, while RA was characterized by enrichment of cell wall remodeling and abscisic acid content associated genes. At ready-to-eat higher contents of flavonoids, abscisic acid and brassinosteroids were associated with color-softening synchronized avocados. In contrast, de-synchronized fruit revealed increases of jasmonic acid, salicylic acid and auxin levels.
  • No Thumbnail Available
    Item
    Analysis of Maillard reaction precursors and secondary metabolites in Chilean potatoes and neoformed contaminants during frying
    (2024) Garcia-Rios, Diego; Hernandez, Ignacia; Alvaro, Juan E.; Pedreschi, Franco; Campos, David; Behn, Anita; Pedreschi, Romina
    Southern Chile native potatoes are an interesting raw material to produce novel snacks like colored potato chips. These novel products should be comprehensively evaluated for the presence of undesirable compounds such as acrylamide, 5-hydroxymethylfurfural and furan, the main neoformed contaminants in starchy rich fried foods. This study evaluated the neoformed contaminant levels and oil content on chips made from eleven Chilean potato accessions and compared them with commercial samples. The neoformed contaminant contents were related to Maillard reaction precursor levels (reducing sugars and asparagine) and secondary metabolites (phenolic compounds and carotenoids). Neoformed contaminants correlated well among them and were weakly correlated with reducing sugars and asparagine. Acrylamide level in native potato chips ranged from 738.2 to 1998.6 mu g kg- 1 while from 592.6 to 2390.5 mu g kg- 1 in commercial samples. Thus, there is need to implement neoformed contaminant mitigation strategies at different steps of the production chain of colored potato chips.
  • Thumbnail Image
    Item
  • No Thumbnail Available
    Item
    Atmospheric immersion and vacuum impregnation of gallotannins and hydrolysed gallotannins from tara pods (Caesalpinia spinosa) mitigate acrylamide and enhances the antioxidant power in potato chips
    (2024) Campos, David; Chirinos, Rosana; Huaraca-Espinoza, Paola; Aguilar-Galvez, Ana; Garcia-Rios, Diego; Pedreschi, Franco; Pedreschi, Romina
    This research aimed to evaluate atmospheric pressure immersion (API) and vacuum impregnation (VI) of non -hydrolyzed and hydrolyzed tara gallotannins (TE and THE) extracts and the purification process by leaching with ethyl acetate (TE-L and THE-L) and absorption chromatography on the acrylamide (AA) mitigation in potato chips. Better results were obtained with THE-L at hydrolysis degrees of 48.5 and 99.8 % and API with AA reduction of 57.9 and 61.7 %, respectively (p > 0.05), while with TE-L, AA reduction was 29.2 %. Instead, THE-L and TE-L with VI reduced AA by 70.3 and 66.4 %, respectively. In potato chips subjected to THE-L treatment, phenolic compounds and ABTS AC increased in 86.5-91.0 % and 71.0-103.2 %, respectively compared to the control. The main antioxidants were identified in the extracts and in potato chips. Tara gallotannins are an interesting alternative to mitigate AA formation and to enhance the antioxidant power of potato chips.
  • No Thumbnail Available
    Item
    Deciphering the behind blackspot exocarp disorder in avocado cv. Hass through a hormonal, transcriptional and metabolic integration approach
    (2024) Nunez-Lillo, Gerardo; Hernandez, Ignacia; Olmedo, Patricio; Ponce, Excequel; Arancibia-Guerra, Camila; Sepulveda, Laura; Carrasco-Pancorbo, Alegria; Beiro-Valenzuela, Maria Gemma; Carrera, Esther; Banos, Jorge; Campos, David; Meneses, Claudio; Pedreschi, Romina
    Avocado cv. Hass is an important sub-tropical crop with an increasing global demand. However, the avocado supply chain experiences significant fruit losses, particularly during the postharvest stage due to diseases and disorders that manifest after prolonged cold storage or the ready-to-eat stage. The blackspot exocarp disorder, which appears as brown or black blotches only after extended cold storage conditions, leads to substantial commercial losses for exported avocados. This research aimed to identify transcriptomic, metabolomic, and hormonal changes in avocado fruits affected by blackspot disorder, differentiating between the green and black exocarp tissues directly impacted by this physiological disorder. The results showed a correlation between the black-colored exocarp of blackspot affected fruits with high levels of gibberellins, cytokinins, jasmonic acid and salicylic acid hormones. Metabolically, these changes were accompanied by a high fatty acid content of oleate, palmitate and linoleate. Using a metabolic pathway reconstruction analysis, we integrated hormonal and metabolic data with transcriptomic information. This approach identified several genes involved in central carbon metabolism, long-chain fatty acid elongation, and jasmonate/salicylate biosynthesis pathways, as well as a possible accumulation of lignins due to a high expression of genes associated with the phenylpropanoid pathway in the black exocarp of blackspot-affected fruits. These findings suggest that blackspot disorder results from a combination of plant defense mechanisms triggered to strengthen the fruit exocarp tissue.
  • Thumbnail Image
    Item
    Ellipticity criteria for ballistic behavior of random walks in random environment
    (2014) Campos, David; Ramírez Chuaqui, Alejandro
  • Thumbnail Image
    Item
    Level 1 quenched large deviation principle for random walk in dynamic random environment
    (2013) Campos, David; Drewitz, Alexander; Ramírez Chuaqui, Alejandro; Rassoul-Agha, Firas; Seppalainen, Timo
  • No Thumbnail Available
    Item
    Postharvest storage and cooking techniques affect the stability of glucosinolates and myrosinase activity of Andean mashua tubers (Tropaeolum tuberosum)
    (2019) Campos, David; Aguilar-Galvez, Ana; Garcia-Rios, Diego; Chirinos, Rosana; Limaymanta, Evelin; Pedreschi, Romina
    The identification and quantification of Glucosinolates (Gls) via UPLC (R) MS-MS/PDA/qToF in ten mashua cultivars was carried out. Gls total contents were within the 4.9-54.2 mu molg(-1) dry matter range, of which 96-99% corresponded to glucoaubrietin. Other less abundant Gls were glucotropaeolin and tentatively two isomers of hydroxybenzyl Gls. Postharvest refrigeration and shade storage conditions increased the content of Gls up to day 6 in 39.7% and 51.5% respectively. Sun exposure increased the Gls content in 40% up to day 3 but from day 6 considerable losses were attained (92% at day 15). Low correlation levels (R-2) between the Gls and myrosinase (MYR) activity of 0.57, 0.28 and 0.39 for the refrigeration, shade and sun exposure treatments were obtained. The cooking regimes tested, boiling, microwaving and baking totally inactivated MYR without affecting the Gls content.
  • No Thumbnail Available
    Item
    Proteomics analysis reveals new insights into surface pitting of sweet cherry cultivars displaying contrasting susceptibility
    (2022) Nunez-Lillo, Gerardo; Ponce, Excequel; Alvaro, Juan E.; Campos, David; Meneses, Claudio; Campos-Vargas, Reinaldo; Carpentier, Sebastien; Fuentealba, Claudia; Pedreschi, Romina
    Surface pitting in sweet cherry (Prunus avium L.) is characterised by depressions development on the skin surface. Pitting damage happens during harvest and postharvest handling and develops during cold storage. This study compared two cultivars with contrasting susceptibility to pitting (Kordia: tolerant; Sweetheart: susceptible) using a LC-MS/MS proteomic approach to identify key metabolic and signalling pathways related to this disorder during ripening and postharvest storage. The variability observed in the principal component analysis was driven by the cultivars suggesting that surface pitting susceptibility is triggered by the inherent differences between cultivars. Proteins involved in anthocyanin biosynthesis were more abundant in Kordia. Moreover, CCR (cinnamoyl-CoA reductase) and FLS (flavonol synthase) proteins showed higher abundance in Sweetheart. An overexpression in enzymes related to the synthesis of abscisic acid (ABA), jasmonic acid (JA) and ethylene were found in Kordia. A higher abundance of sucrose synthase (SUS), UDP-glycosyltransferases (UDP-GT) and polygalacturonase-inhibiting proteins (PGIP) were observed in Kordia, while a higher content of invertase (INV) was observed in Sweetheart. The overexpression of the studied pathways suggests that tolerance to surface pitting could be correlated to one or more of these factors, and susceptibility might be given by the inherent differences in the metabolic processes of each cultivar.
  • Thumbnail Image
    Item
    Tara pod (Caesalpinia spinosa) extract mitigates neo-contaminant formation in Chilean bread preserving their sensory attributes
    (2018) Pedreschi Plasencia, Franco; Saavedra, Ilse; Bunger, Andrea; Zúñiga, Rommy N.; Pedreschi, Romina; Chirinos, Rosana; Campos, David; Mariotti Celis, María Salomé
  • Thumbnail Image
    Item
    Targeted Primary and Secondary Metabolite Analysis of Colored Potato '' Michune Negra '' Grown in Soilless Culture and during Prolonged Cold Storage: Implications in Acrylamide Formation during Frying
    (2023) García Ríos, Diego; Álvaro, Juan E.; Zúñiga, María Elvira; Campos, David; Aguilar Gálvez, Ana; Mariotti Celis, María Salomé; Pedreschi Plasencia, Franco Wilfredo; Pedreschi, Romina
    Colored potatoes have been of interest because of their nutritional and health-promoting properties. However, their aptitude for processing regarding acrylamide formation levels is highly variable and for the most part unknown. In this work, the effect of cultivation season (summer and winter), and postharvest cold storage (1, 2, and 5 months at 5 C-circle +/- 1 C-circle) on the Maillard reaction precursors (reducing sugars, sucrose, and asparagine), phenolic compounds (anthocyanins, phenolic acids and other flavonoids), and acrylamide after frying (GC-MS) were assessed on the '' Michune negra '' potato cultivar from the southern region of Chile grown under fertigation. Acrylamide levels were surveyed on six samples of commercial colored potato chips for comparison purposes. Cultivation season and cold storage showed an effect on both main primary and secondary metabolites. The amount of reducing sugars such as fructose increased with cold storage. Anthocyanin and phenolic contents were higher in the winter season and increased with cold storage. Acrylamide levels were high, surpassing the EFSA benchmark value (750 mu g kg (-1)) in all cases, notably in chips made after one month of cold storage (2125% higher). Additional measures in both agronomical and processing stages of the purple-fleshed potato need to be implemented to lower the acrylamide levels down to acceptable values.