DSpace Angular :: Browsing by Author "Pedreschi, Romina"

Browsing by Author "Pedreschi, Romina"

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A First Omics Data Integration Approach in Hass Avocados to Evaluate Rootstock-Scion Interactions: From Aerial and Root Plant Growth to Fruit Development
(2024) Nunez-Lillo, Gerardo; Ponce, Excequel; Beyer, Clemens P.; Alvaro, Juan E.; Meneses, Claudio; Pedreschi, Romina
Grafting, the careful selection of rootstocks and scions, has played a crucial role maintaining Chilean avocado fruit quality standards in a scenario in which climate change and drought-related issues have considerably decreased avocado fruit production in the last fifteen years. The historical use of seedling rootstocks in Chile has experienced a recent shift towards clonal rootstocks, driven by the potential to produce more consistent and predictable crops. This research aims to compare Hass avocado plants grafted on Mexicola seedling and Dusa (R) clonal rootstocks in a soilless and protected system using (i) a differential expression analysis of root and leaf samples and (ii) a fruit transcriptomic and metabolomic integration analysis to improve our understanding of rootstock-scion interaction and its impact on avocado tree performance and fruit quality. The results demonstrated that no significant transcriptomic and metabolomic differences were identified at fruit level in the ready-to-eat (RTE) stage for Hass avocado fruit from both rootstocks. However, Hass avocados grafted on the clonal rootstock showed greater aerial growth and slightly increased fruit size than the seedling rootstock due to the enrichment of cell wall-remodeling genes as revealed in leaves and fruit at harvest stage.
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.
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.
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.
Cell wall disassembly, metabolome and transcriptome analysis in sweet cherry fruit with induced surface pitting
(2023) Ponce, Excequel; Nunez-Lillo, Gerardo; Bravo, Camila; Vidal, Juan; Tapia Reyes, Patricio; Meneses, Claudio; Pedreschi, Romina; Fuentealba, Claudia
Surface pitting is the main quality problem that develops during prolonged storage of sweet cherries. It appears as one or more depressions on the surface of the fruit and is associated with the collapse of cells under the skin of the fruit. However, this physiological disorder is not shown in all cultivars with the same intensity. This research aims to analyze the cell wall disassembly of two cultivars displaying contrasting susceptibility to damage after pitting induction. In addition, we evaluated the metabolomic and transcriptomic changes in sweet cherries during cold storage. Our results show that damage to 'Sweetheart' fruit was more severe than damage to 'Bing' fruit. No differences were observed in the cell wall composition between nonpitted and pitted cherries; however, the varietal differences during cold storage were the most significant. The resistant cultivar 'Bing' showed a longer sidechain of RG-I; instead, 'Sweetheart' PME and PG activity was more marked at the beginning of cold storage. The metabolomics analysis revealed several compounds related to the abiotic stress response, such as 3O-coumaroyl-D-quinic acid, chlorogenic acid, GABA and beta-sitosterol. Furthermore, transcriptomics showed a higher expression of stress-related hormones in the susceptible cultivar and cell wall remodeling-related genes in the resistant cultivar. In conclusion, the contrasting susceptivity to surface pitting in sweet cherries can be attributed to the varietal response to cold storage rather than the mechanical stress of pitting induction.
Color desynchronization with softening of 'Hass' avocado: Targeted pigment, hormone and gene expression analysis
(2022) Arancibia-Guerra, Camila; Nunez-Lillo, Gerardo; Caceres-Mella, Alejandro; Carrera, Esther; Meneses, Claudio; Kuhn, Nathalie; Pedreschi, Romina
Main determinants of 'Hass' avocado quality and consumer acceptance are mesocarp firmness and skin color. Relevant producing and exporting countries have evidenced during the last seasons color desynchronization with softening at edible ripeness. The mechanisms driving this desynchronization are still unknown. Thus, this study aimed to provide a first deep insight into this problem by combining targeted pigment, hormone and gene expression analysis in avocado exocarp samples from different harvests and storage conditions. Results showed that color desynchronization was more pronounced in regular air (RA) condition and early harvest for all or-chards. Prolonged controlled atmosphere (CA) storage synchronized color development in all orchards analyzed. Chlorophylls and carotenoids did not decrease in content as the fruit reached the ready to eat stage but remained stable while total anthocyanins increased in all evaluated orchards. Total anthocyanins and abscisic acid were strongly and positively correlated with the "black color" phenotype. The other evaluated hormones (JA, IAA, SA, tZ, DHZ, iP) revealed negative correlations with the "black color" phenotype. Gene expression related to the ethylene biosynthesis pathway (PamACS, PamETR avocado gene orthologues) showed an up-regulation in fruit phenotyped as ready to eat (RTE) Green. In addition, the expression of the genes orthologues PamPAL, PamF3H and PamCHS was also positively correlated with anthocyanin content in the skin. Our results revealed that color desynchronization with softening of 'Hass' avocado is quite complex in terms of hormonal interplay and the role of storage conditions (RA vs CA). Thus, further studies need broader approaches such as the incorporation of omics studies to elucidate the physiological and molecular mechanisms driving color desynchronization.
Color development and acrylamide content of pre-dried potato chips
(ELSEVIER SCI LTD, 2007) Pedreschi, Franco; Leon, Jorge; Mery, Domingo; Moyano, Pedro; Pedreschi, Romina; Kaack, Karl; Granby, Kit
The objective of this work was to study the development of color formation in pre-dried potato slices during frying and acrylamide formation in the final potato chips. Color measurement was done by using an inexpensive computer vision technique which allowed quantifying representatively and precisely the color of complex surfaces such as those of potato chips in L*a*b* units from RGB images. Prior to frying, potato slices (Desiree variety, diameter: 37 mm, width: 2.2 mm) were blanched in hot water at 85 degrees C for 3.5 min. Unblanched slices were considered as the control. Slices of the same dimensions were blanched as in the previous step, and then air-dried until reaching a moisture content of 60% (wet basis). These samples were called pre-dried potato slices. Potato slices were fried at 120 degrees C, 140 degrees C, 160 degrees C and 180 degrees C until reaching moisture contents of similar to 1.8% (total basis) for color quantification. Acrylamide concentration was determined only in final chips fried at 120 degrees C, 150 degrees C and 180 degrees C and compared with that of two brands of commercial chips produced in Chile (Moms and Frito Lay). Color values in L*a*b* units were recorded at different sampling times during frying at the four mentioned temperatures using the total color difference parameter (Delta E). Pre-drying did not affect the color of potato chips considerably when compared against blanched chips; however when fried at 180 degrees C, pre-dried potato chips present 44%, 22%, 44% lower acrylamide content than that of the control, Moms and Frito Lay chips, respectively. (c) 2006 Elsevier Ltd. All rights reserved.
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.
Effect of the Integrated Addition of a Red Tara Pods (Caesalpinia spinosa) Extract and NaCl over the Neo-Formed Contaminants Content and Sensory Properties of Crackers
(2022) Pedreschi Plasencia, Franco Wilfredo; Matus, Joans; Bunger, Andrea; Pedreschi, Romina; Huaman Castilla, Nils Leander; Mariotti Celis, Maria Salome
A 2k factorial design with three centrals points was considered to evaluate the effect of adding red Tara pods extract (Caesalpinia spinosa) (440-2560 mu g/mL of dough water) and NaCl (0.3-1.7 g/100 g of flour) on the acrylamide (AA) and hydroxymethylfurfural (HMF) content and sensory attributes of crackers. Additionally, the best formulation, defined as that with the lowest AA and HMF content, was compared with a commercial formulation cracker. Red Tara pods extracts were obtained through conventional extraction using pure water (60 degrees C, 35 min). AA and HMF content were quantified by GC-MS and HPLC-DAD, respectively. The sensory evaluation was carried out using a descriptive analysis on a 10 cm non-structured linear scale. Red Tara pods extract significantly reduced (p < 0.05) the AA and HMF content, while NaCl only influenced the HMF formation. However, the sensory attributes did not significantly change (p > 0.05), excepting the violet-gray color and salty flavor, but at acceptable levels compared with the control sample. The higher the red Tara pods extract concentration (2560 mu g/mL of dough water), the lower the neo-formed contaminants (NFCs) content of crackers (AA: 53 mu g/kg and HMF: 1236 mu g/kg) when salt level was below 3 g/100 g of flour. The action of the proanthocyanidins present in the extracts which trapped the carbonyl groups of sugars probably avoided the formation of both NFCs. Contrarily, NaCl addition (from 0.3 to 1.7 g/100 g of flour) significantly increased (p < 0.05) the HMF formation (from 1236 mu g/kg to 4239 mu g/kg, respectively), probably through the dehydration of carbohydrates during the Maillard reaction. When explored treatments were compared with a commercial formulated cracker, the highest mitigation effect (reductions of 40% and 32% AA and HMF, respectively) was reached with the addition of 2560 mu g/mL of dough water of red Tara pods extract and 0.3 g/100 g of flour of NaCl. The addition of red Tara pods extracts integrated with the control of NaCl levels mitigated the NFCs in crackers, preserving their sensory properties. Future research should be focused on scaling this mitigation technology, considering a better chemical characterization of red Tara pods extracts as well as the validation of its use as functional food ingredient.
Fruit sugar hub: gene regulatory network associated with soluble solids content (SSC) in Prunus persica
(2024) Núñez Lillo, Gerardo; Lillo Carmona, Victoria; Pérez Donoso, Alonso Gastón; Pedreschi, Romina; Campos Vargas, Reinaldo; Meneses Araya, Claudio Antonio
Chilean peach growers have achieved worldwide recognition for their high-quality fruit products. Among the main factors influencing peach fruit quality, sweetness is pivotal for maintaining the market's competitiveness. Numerous studies have been conducted in different peach-segregating populations to unravel SSC regulation. However, different cultivars may also have distinct genetic conformation, and other factors, such as environmental conditions, can significantly impact SSC. Using a transcriptomic approach with a gene co-expression network analysis, we aimed to identify the regulatory mechanism that controls the sugar accumulation process in an 'O × N' peach population. This population was previously studied through genomic analysis, associating LG5 with the genetic control of the SSC trait. The results obtained in this study allowed us to identify 91 differentially expressed genes located on chromosome 5 of the peach genome as putative new regulators of sugar accumulation in peach, together with a regulatory network that involves genes directly associated with sugar transport (PpSWEET15), cellulose biosynthesis (PpCSLG2), flavonoid biosynthesis (PpPAL1), pectin modifications (PpPG, PpPL and PpPMEi), expansins (PpEXPA1 and PpEXPA8) and several transcription factors (PpC3H67, PpHB7, PpRVE1 and PpCBF4) involved with the SSC phenotype. These results contribute to a better understanding of the genetic control of the SSC trait for future breeding programs in peaches.
Metabolite Profiling Reveals the Effect of Cold Storage on Primary Metabolism in Nectarine Varieties with Contrasting Mealiness
(2023) Olmedo, Patricio; Zepeda, Baltasar; Delgado-Rioseco, Joaquin; Leiva, Carol; Moreno, Adrian A.; Sagredo, Karen; Blanco-Herrera, Francisca; Pedreschi, Romina; Infante, Rodrigo; Meneses, Claudio; Campos-Vargas, Reinaldo
Chilling injury is a physiological disorder caused by cold storage in peaches and nectarines. The main symptom of chilling injury is mealiness/wooliness, described as a lack of juice in fruit flesh. In this work, we studied two nectarine varieties (Andes Nec-2 and Andes Nec-3) with contrasting susceptibility to mealiness after cold storage. A non-targeted metabolomic analysis was conducted by GC-MS to understand if changes in metabolite abundance are associated with nectarine mealiness induced by cold storage. Multivariate analyses indicated that in unripe nectarines, cold storage promoted a higher accumulation of amino acids in both varieties. Interestingly, for ripe nectarines, cold storage induced an accumulation of fewer amino acids in both varieties and showed an increased abundance of sugars and organic acids. A pathway reconstruction of primary metabolism revealed that in ripe nectarines, cold storage disrupted metabolite abundance in sugar metabolism and the TCA cycle, leading to a differential accumulation of amino acids, organic acids, and sugars in mealy and juicy nectarines.
Metabolomic and biochemical analysis of mesocarp tissues from table grape berries with contrasting firmness reveals cell wall modifications associated to harvest and cold storage
(2022) Balic, Ivan; Olmedo, Patricio; Zepeda, Baltasar; Rojas, Barbara; Ejsmentewicz, Troy; Barros, Miriam; Aguayo, Daniel; Moreno, Adrian A.; Pedreschi, Romina; Meneses, Claudio; Campos-Vargas, Reinaldo
Tissue texture influences the grape berry consumers acceptance. We studied the biological differences between the inner and outer mesocarp tissues in hard and soft berries of table grapes cv NN107. Texture analysis revealed lower levels of firmness in the inner mesocarp as compared with the outer tissue. HPAEC-PAD analysis showed an increased abundance of cell wall monosaccharides in the inner mesocarp of harder berries at harvest. Immunohistochemical analysis displayed differences in homogalacturonan methylesterification and cell wall calcium between soft and hard berries. This last finding correlated with a differential abundance of calcium measured in the alcohol-insoluble residues (AIR) of the inner tissue of the hard berries. Analysis of abundance of polar metabolites suggested changes in cell wall carbon supply precursors, providing new clues in the identification of the biochemical factors that define the texture of the mesocarp of grape berries.
NAC072 Interacts with HB12, HAT9, and MYBR1 in a Temporal Regulatory Network Controlling Peach Fruit Development
(2023) Nunez-Lillo, Gerardo; Zabala, Jose; Lillo-Carmona, Victoria; Alvarez, Jose Miguel; Pedreschi, Romina; Meneses, Claudio
Fruit development is a complex process that involves the interplay of different biological processes carefully coordinated to control fruit quality traits. The peach fruit development consists in four recognized growth stages (S1-S4). The second stage (S2) is characterized by the endocarp hardening process and is followed by the second exponential growth phase (S3), where an increase in fruit size is produced by a rapid cell expansion. A nectarine genotype incapable of ripening and described as a slow ripening phenotype was identified and selected as a good model for studying peach fruit development. Slow ripening fruit remained firm, green, and exhibited no rise in CO2 or ethylene production rates blocking fruit development at S3 stage. The transcription factor NAC072 has been proposed as a key regulatory element involved in both the slow ripening and the harvest date phenotypes. However, the regulatory mechanisms by which NAC072 produces these phenotypic changes are still unknown. Using a transcriptomic approach between normal and slow ripening individuals with a transcription factor-gene target interaction database, a NAC072 regulatory network was constructed, identifying putative direct and indirect NAC072 fruit development-related elements. Three transcription factors were identified along with NAC072 in early stages of fruit development, two homeobox-leucine zippers (HB12 and HAT9), and one MYB transcription factor (MYBR1). In addition, we determined that the NAC072 transcriptional regulatory network promotes phenylpropanoids biosynthesis and cell wall remodeling to develop fruit growth, seed development, and softening, probably through hormonal signaling pathways involving abscisic acid and gibberellic acid.
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.
Proteomic and Low-Polar Metabolite Profiling Reveal Unique Dynamics in Fatty Acid Metabolism during Flower and Berry Development of Table Grapes
(2023) Olmedo, Patricio; Vidal, Juan; Ponce, Excequel; Defilippi, Bruno G.; Perez-Donoso, Alonso G.; Meneses, Claudio; Carpentier, Sebastien; Pedreschi, Romina; Campos-Vargas, Reinaldo
Grapevine development and ripening are complex processes that involve several biochemical pathways, including fatty acid and lipid metabolism. Fatty acids are essential components of lipids, which play crucial roles in fruit maturation and flavor development. However, the dynamics of fatty acid metabolism in grape flowers and berries are poorly understood. In this study, we present those dynamics and investigate the mechanisms of fatty acid homeostasis on 'Thompson Seedless' berries using metabolomic and proteomic analyses. Low-polar metabolite profiling indicated a higher abundance of fatty acids at the pre-flowering and pre-veraison stages. Proteomic analyses revealed that grape flowers and berries display unique profiles of proteins involved in fatty acid biosynthesis, triacylglycerol assembly, fatty acid beta-oxidation, and lipid signaling. These findings show, for the first time, that fatty acid metabolism also plays an important role in the development of non-oil-rich tissues, opening new perspectives about lipid function and its relation to berry quality.
Proteomic and metabolomic integration reveals the effects of pre-flowering cytokinin applications on central carbon metabolism in table grape berries
(2023) Olmedo, Patricio; Nunez-Lillo, Gerardo; Vidal, Juan; Leiva, Carol; Rojas, Barbara; Sagredo, Karen; Arriagada, Cesar; Defilippi, Bruno G.; Perez-Donoso, Alonso G.; Meneses, Claudio; Carpentier, Sebastien; Pedreschi, Romina; Campos-Vargas, Reinaldo
Consumers around the world prefer high quality table grapes. To achieve higher quality traits at ripening, grapevine producers apply different plant growth regulators. The synthetic cytokinin forchlorfenuron N- (2-chloro-4-pyridinyl)-N '-phenylurea (CPPU) is widely used, its effect on grape quality is poorly understood. We hypothesized that the use of CPPU in pre-flowering can lead to changes in the metabolism that affects grape quality at harvest. Therefore, we investigated the role of CPPU applications on the quality of grapes by inte-grating proteomics and metabolomics. CPPU-treated grapevines showed a significant increase in berry size and firmness. Proteomic analyses indicated that CPPU-treated berries accumulated enzymes associated with carbo-hydrate metabolism, glycolysis, and tricarboxylic acid (TCA) cycle at harvest. Metabolomic analyses showed shifts in the abundance of compounds associated with carbohydrate metabolism and TCA cycle in CPPU-treated grapes. These findings suggest that CPPU applications modulate central carbon metabolism, improving grape berry quality.
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.
Response Mechanisms of "Hass" Avocado to Sequential 1-methylcyclopropene Applications at Different Maturity Stages during Cold Storage
(2022) Olivares, Daniela; Garcia-Rojas, Miguel; Ulloa, Pablo A.; Riveros, Anibal; Pedreschi, Romina; Campos-Vargas, Reinaldo; Meneses, Claudio; Defilippi, Bruno G.
1-Methylcyclopropene (1-MCP) is used for extending the postharvest life of the avocado during storage. Evaluated the effect of 1-MCP application at different times after harvest, i.e., 0, 7, 14, and 21 d at 5 degrees C, to identify the threshold of the ethylene inhibition response in "Hass" avocado. Our results showed that fruits from two maturity stages at harvest: low dry matter (20-23%) and high dry matter (27%). Changes in ethylene production rates and transcript accumulation of genes involved in ethylene metabolism were measured at harvest and during storage. 1-MCP treated fruit up to 14 d of storage showed similar values of firmness and skin color as fruit treated at harvest time. In contrast, when the application was performed after 21 d, the fruit showed ripening attributes similar to those of the untreated ones. To further understand the molecular mechanisms responsible for the lack of response to 1-MCP at 21 d of storage, transcriptomic analysis was performed. Gene ontology analyses based on the DEG analysis showed enrichment of transcripts involved in the 'response to ethylene' for both maturity stages. All genes evaluated showed similar expression profiles induced by cold storage time, with a peak at 21 d of storage and an increased softening of the fruit and peel color. This was a two-year field study, and results were consistent across the two experimental years. Our results should help growers and markets in selecting the optimal timing of 1-MCP application in "Hass" avocados and should contribute to a deeper understanding of the molecular mechanisms of the avocado ripening process.
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
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.

Browsing by Author "Pedreschi, Romina"

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