Romina Pedreschi

Pontifical Catholic University of Valparaíso | PUCV · School of Agronomy

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 fi...

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 to develop biomarkers...

The objective of this study was to identify transcripts or hormone-based biomarkers to define the physiological age of ′ Hass ′ avocado fruit and to elucidate the changes at the level of metabolic pathways and their regulation. ′ Hass ′ avocado fruit from orchards in different agroclimatic zones were collected during two harvest periods. Fruit were...

Avocado consumption and trade are increasing worldwide, with North America and Europe being the main importing regions. Spain is the major European avocado producer (90% of the production), yet it only supplies 10% of the market. Consequently, more than 90% of the avocados consumed in Europe are imported from overseas, mainly from Chile and Peru. I...

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 br...

Context: Several signals control transition from development to ripening in fruits, including hormones and metabolites, which is accompanied by intense transcriptomic remodeling. However, these signals have been poorly investigated in non-climacteric fruit species such as sweet cherry. Seeds may modulate ripening, since communication between embryo...

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 cult...

Color development in avocado fruits is a complex mechanism influenced by several factors. To understand this process, a comparative analysis was conducted between fruits of 'Fuerte' and 'Hass' avocado cultivars using metabolomic approaches. Pigment content in the exocarp differs between cultivars, accumulating anthocyanins in 'Hass' avocado. Carboh...

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...

During ripening, ‘Hass’ avocado skin changes from green to purple/black. Low-temperature storage with a controlled atmosphere (CA) is the most widely used method for avocado storage; however, few studies have simulated this technology and considered the days of regular air (RA) storage prior to CA storage. Herein, the effect of delaying the storage...

This study evaluated the impact of in silico simulated gastrointestinal digestion (GID) of four quinoa globulins on the potential to release ACE and DPP-IV inhibitor peptides (antihypertensive and antidiabetic properties, respectively), as well as performed a molecular docking study to evaluate the interactions produced in the peptide-enzyme comple...

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...

The present study evaluated the performance of some enzymatic and non-enzymatic antioxidant systems against oxidative stress for 10 to 30 d of refrigeration (R) and 15 to 50 d in controlled atmosphere (CA) conditions in both exocarp and mesocarp of Hass avocados from early and late harvests and at shelf life (SL) or consumption maturity. The possib...

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...

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 und...

Postharvest avocado losses are mainly due to anthracnose disease caused by Colletotrichum gloeosporioides. Chemical fungicides are effective, but their negative effects on health and the environment have led to the search for sustainable alternatives such as biopolymer-based coatings and natural compounds. Therefore, chitin nanocrystals (NCChit) we...

Spain dominates avocado production in Europe, with the Hass variety being the most prominent. Despite this, Spanish production satisfies less than 10% of the overall avocado demand in Europe. Consequently, the European avocado market heavily relies on imports from overseas, primarily sourced from Peru and Chile. Herein, a comprehensive characteriza...

Sweet cherry may develop surface pitting during prolonged cold storage, and susceptibility among varieties is related to metabolites in response to cold and mechanical damage. This study aimed to evaluate the metabolic changes in sweet cherry fruits subjected to melatonin treatment and induced surface pitting. Melatonin (400 µM) was applied to swee...

The present research aimed to evaluate three peptides synthesised from tarwi: AVPFWM, YSGWLGL and AHAGFGMLY in their antioxidant, antihypertensive and hypoglycemic properties, using in vitro and in silico studies, this last one considering the molecular docking evaluation and ADMET (absorption, distribution, metabolism, excretion and toxicity) prop...

The angiotensin I converting enzyme (ACE, antihypertensive effect) and dipeptidyl peptidase IV (DPP IV, antidiabetic effect) inhibitory potential of peptides derived from the quinoa globulin hydrolysis with thermolysin were evaluated by in silico and in vitro analysis. The in silico hydrolysis of the globulin fractions resulted in peptides (~400 se...

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 o...

The classification of grapevine cultivars into isohydric and anisohydric categories depends on their ability to close stomata under conditions of low soil water availability or high atmospheric demand. This study aimed to compare the responses of Grenache, classified as isohydric, and Cabernet Sauvignon, classified as anisohydric, both grafted onto...

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...

Avocado fruit growth and development, unlike that of other fruits, is characterized by the accumulation of oil and C7 sugars (in most fruits, the carbohydrates that prevail are C6). There are five essential carbohydrates which constitute 98% of the total content of soluble sugars in this fruit; these are fructose, glucose, sucrose, d-mannoheptulose...

The high maize (Zea mays L.) diversity in Peru has been recognized worldwide, but the investigation focused on its integral health-relevant and bioactive characterization is limited. Therefore, this research aimed at studying the variability of the primary and the secondary (free and dietary fiber-bound phenolic, and carotenoid compounds) metabolit...

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-t...

The choice of rootstock has a significant impact, not only on fruit growth and development, but also on avocado fruit quality and postharvest performance. The objective of this study was to evaluate and compare attributes related to the postharvest quality of Hass avocados from “Mexicola” and “Duke 7” rootstocks grown under similar conditions. This...

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 ai...

Some bioactive compounds in paico (Dysphania ambrosioides) leaves were characterised. By LC–MS/MS‐QToF, 20 polyphenols were found: vanillic acid, one p‐coumaroyl‐hexoside acid derivative, three quercetin‐rhamnoside derivatives, one quercetin derivative, two kaempferol acetyl‐furanoside‐rhamnoside derivatives and twelve kaempferol‐rhamnoside derivat...

Harvest date is a critical parameter for producers and consumers regarding agro-industrial performance. It involves a pleiotropic effect controlling the development of other fruit quality traits through finely controlling regulatory mechanisms. Fruit ripening is a process in which various signals and biological events co-occur and are regulated by...

The goal of this study was to use GC‐MS and UHPLC‐UV‐VIS‐based metabolomic tools combined with chemometric analysis to discriminate between fruit with blackspot physiological disorder independently of storage condition (regular air or controlled atmosphere) and without blackspot (hereafter referred to as ‘Control’). The study looked at polar metabo...

Mashua (Tropaeolum tuberosum), an Andean crop used in traditional medicine, has become of interest due to its phytochemicals specifically glucosinolates (GLS). Little is known about the impacts of cold storage and drying processing operations on the GLS composition of mashua‐derived products. This work evaluated the changes in GLS content and profi...

Tarwi is an Andean grain, belonging to the legume group and is characterised by its high protein content, exceeding that reported in soybeans being an interesting resource for obtaining bioactive peptides. The tarwi protein hydrolysate (TPH) obtained by enzymatic hydrolysis with Alcalase (60 min) followed by Neutrase (120 min) presented important m...

Mashua (Tropaeolum tuberosum) is an Andean tuber with a high content of glucosinolates (GLSs). GLSs subjected to biotransformation by plant enzymes or enzymes of the gastrointestinal microbiota give rise to biologically active compounds, to which chemo preventive properties are attributed. In this work, the biotransformation of mashua GLSs was eval...

Light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds through photosynthesis, and this process is of high importance in the maintenance of life on Earth. On the other hand, plant growth-promoting rhizobacteria (PGPR) are a diverse group of bacteria that can be found in the rhi...

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 abund...

This work evaluated the enzymatic and non-enzymatic antioxidant defense systems of avocados cv. Hass stored at 7 ± 0.5 °C for 10, 20, and 30 d, and at the stage of edible ripeness. The enzymatic antioxidant enzyme system included superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the non-enzymatic antioxidant system was composed...

Devices which are used to determine firmness of non-destructive nature do not penetrate the skin or damage the underlying flesh of the fruit and do provide real-time results, avoid raw biomass loss and allow the testing of every individual fruit and repeated testing of the same fruit, thus providing many advantages for researchers and the industry...

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 °C, to identify the threshold of the ethylene inhibition response in “Hass” avocado. Our results showed that fruits from two maturity stages...

When the recipient of the product is relatively distant from the production area, it is necessary to use cold storage and controlled humidity to transport the avocado fruits. One of the main advantages of local avocado consumption lies on the possibility of prolonging on-tree maturation; this could foreseeably modify the metabolic profile of the fr...

Quinoa proteins were enzymatically hydrolyzed using Neutrase at 50°C/120 min in order to study their antioxidant as well as the angiotensin-I converting enzyme (ACE) inhibitory activities. Subsequently, ultrafiltration (sequentially, 10 and 3 kDa cut-off membranes) and chromatographic techniques (adsorption and size-exclusion chromatography) were a...

As it was previously reported, black spot development in the skin of Hass avocado has been related to a decreased antioxidant defense system. The aim of this study was to investigate the effect of different postharvest storage conditions on controlling black spot development targeting their effect on the antioxidant system (non-enzymatic and enzyma...

Avocados (Persea americana Mill.) are one of the crops with the highest water footprints in Chile and the production is at risk due to severe and frequent droughts. The current production is mostly based on sexually (seed) propagated rootstocks, while clonally propagated rootstocks are on the rise. In a recent study, we found differences in aerial,...

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...

A 2k factorial design with three centrals points was considered to evaluate the effect of adding red Tara pods extract (Caesalpinia spinosa) (440-2560 µg/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, define...

This study aimed to optimize the extraction of phenolic compounds (PC) and the antioxidant capacity (AC) of Inca muña by conventional solvent extraction (CSE) and ultrasound‐assisted extraction (UAE). Optimization was performed by response surface methodology. CSE evaluated variables included EtOH (%), temperature, and time; UAE evaluated variables...

ACRYLAMIDE MITIGATION IN POTATO CHIPS BY ADDITION OF POLYPHENOLS FROM INCA MUÑA (Chenopodium bolivianum). The aim of this study was to evaluate the influence of Inca muña phenolic antioxidants in the reduction of acrylamide (AA) in potato chips. The potatoes were cut into 2 mm thick slices, the addition of antioxidants was evaluated by immersion at...

The use of plant growth regulators (PGRs) is widespread in commercial table grape vineyards. The synthetic cytokinin CPPU is a PGR that is extensively used to obtain higher quality grapes. However, the effect of CPPU on berry firmness is not clear. The current study investigated the effects of pre-anthesis applications (BBCH15 and BBCH55 stages) of...

Avocado cv. Hass consumption has expanded worldwide given its nutritional, sensory, and functional attributes. In this work, avocado fruit from two harvests was subjected to hydrothermal treatment (38 °C for 1 h) or left untreated (control) and then stored for 30 and 50 days in a controlled atmosphere (4 kPa O2 and 6 kPa CO2 at 7 °C) (HTCA and CA,...

Fruit development is a complex process that involves the interplay of cell division, expansion, and differentiation. As a model to study fruit development, nectarines incapable of ripening were described as slow ripening. Slow ripening fruits remained firm and exhibited no rise in CO2 or ethylene production rates for one month or more at 20 °C. Dif...

Avocado (Persea americana) production is nowadays questioned due to its environmental impact, especially water footprint. Avocado rootstocks have been developed to enhance the resistance to environmental conditions but not for resource efficiency. In this study, physiological parameters of 18 months old vegetatively- (clonally-) propagated (Dusa®)...

Purple corn (Zea mays L.) is native to the Andean region, but limited research has been performed about the potential metabolic variability when grown under Andean environmental conditions. This study was aimed at evaluating the phenolic and primary polar metabolites composition of purple corn (kernels and cobs) grown at two Peruvian Andean locatio...

Black spot corresponds to a physiological disorder of the type of oxidative stress that occurs after the prolonged postharvest storage of Persea americana Mill. cv. Hass fruit. Industry tends to confuse this disorder with pathogen attack (Colletotrichum gloeosporioides), chilling injury, mechanical damage during harvest and transport or lenticel da...

This work aimed evaluating some physicochemical compounds, hydrophilic (H‐AC) and lipophilic (L‐AC) antioxidant capacity of eleven avocado genotypes grown in the Andes. The results show great variability in physical and chemical properties, dry matter (DM) and lipid contents with ranges of 18.4–39.3% and 10.1–23.2%, respectively. All genotypes had...

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseni...

Table grapes (Vitis vinifera) are affected by botrytis bunch rot and summer bunch rot, the latter a complex disease caused by Botrytis cinerea, Aspergillus spp., Penicillium expansum and Rhizopus stolonifer. To search for biocontrol alternatives, a new bioproduct composed of Gluconobacter cerinus and Hanseniaspora osmophila, a consortium called PUC...

One important physiological disorder in sweet cherry (Prunus avium L.) is surface pitting. This disorder involves irregular depressions on the fruit surface and occurs during harvest, but it develops during cold storage. The aim of this research was to understand the phenotypic characteristics and biochemical responses, referring to the metabolomic...

Avocado production is nowadays questioned worldwide and at risk due to climate change and the high water footprint of this crop. Thus, there is need for the development or adoption of new strategies such as alternative production systems. In this study, Hass avocado plants grafted on two rootstocks (Mexicola-seed propagated and Dusa®-vegetative-pro...

The objective of this work was to identify primary and secondary metabolites, volatile compounds, bioactive properties and physicochemical characteristics of lucuma fruit at two ripeness stages, before physiological maturity (bPM) and at physiological maturity (PM) or commercial harvest.