Michelle Guijarro

Dr. Michelle Guijarro

CIDCA, La Plata, Buenos Aires, Argentina
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 March 2019 in Foods
Verified
Journal Article
Open access
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LSLorena Salvador
Lorena Salvador
Michelle GuijarroMichelle Guijarro
Michelle Guijarro
DRDaniela Rubio
Daniela Rubio
BABolívar Aucatoma
Bolívar Aucatoma
TGTanya Guillén
Tanya Guillén
LRLuis Ramos
Luis Ramos
Honey is one of the oldest sweetening foods and has economic importance, making this product attractive to adulteration with cheap sugars. This can cause a critical problem in the honey industry and a possible health risk. The present work has the aim of evaluating the authenticity of honey commercialized in two different provinces of Ecuador (Pichincha and Loja) by performing physicochemical and spectroscopic analyses. For this study 25 samples were collected from different places and markets and characterized by water, sucrose, reducing sugars and electric conductivity measurement. Also, their Raman and Infrared (IR) spectra were recorded and analysed using a Principal Component Analysis (PCA) in order to verify the quality of the honeys. In addition, a screening of several pesticides was performed in order to verify possible chemical threats to human health and honey bees. It was found that 8 samples have a deviation from the Standard established parameters. Two of them have a high difference in the content of sucrose and reducing sugars, which are located deviated from all the other samples in the PCA of the applied vibrational spectroscopy (IR/Raman), shaping two clear clusters. The results show that Raman and IR spectroscopy is appropriate techniques for the quality control of honey and correlates well with the physicochemical analyses.

1 June 2019 in Food Science and Technology
Verified
Journal Article
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Michelle GuijarroMichelle Guijarro
Michelle Guijarro
MAMaria Jose Andrade-Cuvi
Maria Jose Andrade-Cuvi
JBJuan Eduardo Bravo
Juan Eduardo Bravo
LRLuis Ramos
Luis Ramos
MVMaria Gabriela Vernaza
Maria Gabriela Vernaza
The Andean Blueberry (Vaccinium floribundum) is a fruit with a recognized antioxidant capacity. Its consumption is limited to typical food in the Andean Ecuadorian zones. In this study, the effect of the addition of Andean blueberry (AB) pulp on loaf bread quality was determined. The specific volume was affected by the low fermentation rate due to the acidic pH of the fruit. The texture profile measurement demonstrated a product with harder consistency, due to the low number and circularity of the alveoli. Higher air retention in the crumb was also found. Simulated Gastrointestinal conditions directly affected the antioxidant capacity of the AB, producing a reduction of 96.9%. On the other hand, the AB bread initially presented a value of 37 μM Trolox/g and, after the digestion process, a value of 10.6 μM Trolox/g, corresponding to a percentage of bioaccessibility of 28.6%. The global results indicate that the gluten network would protect the antioxidant compounds of the AB. It was possible to develop bread with healthier properties, due to the high antioxidant content of the AB.

13 June 2024 in Metabolites
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Journal Article
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MDMagali Darré
Magali Darré
MZMaria Jose Zaro
Maria Jose Zaro
Michelle GuijarroMichelle Guijarro
Michelle Guijarro
LCLudmila Careri
Ludmila Careri
Analía ConcellónAnalía Concellón
Analía Concellón
Bell peppers (Capsicum annuum L.) are prone to chilling injury (CI) when stored at temperatures below 7 °C. Melatonin, a natural plant regulator, plays a critical role in defending against different pre- and post-harvest abiotic stresses, including those associated with cold storage. This study aimed to assess the effects of applying exogenous melatonin alone and in combination with a commercial wax on the CI tolerance, postharvest life, and potential biomarker search of red bell peppers. In the initial experiment, the effective melatonin concentration to reduce CI effects was determined. Peppers were sprayed with either distilled water (control) or a melatonin aqueous solution (M100 = 100 μM or M500 = 500 μM) and then stored for 33 d at 4 °C, followed by 2 d at 20 °C. The M500 treatment proved to be more effective in reducing fruit CI incidence (superficial scalds) and metabolic rate, while weight loss, softening, and color were comparable to the control. A second experiment assessed the potential synergistic effects of a combined melatonin and commercial wax treatment on pepper CI and quality. Fruits were sprayed with distilled water (control), melatonin (M500), commercial wax (Wax), or the combined treatment (Wax + M500) and stored for 28 d at 4 °C, followed by 2 d at 20 °C. The Wax + M500 was the most effective in significantly reducing the incidence of fruit CI symptoms and calyx fungal infection. Furthermore, this combined treatment enhanced fruit weight loss prevention compared with individual melatonin or wax treatment. Also, Wax + M500-treated peppers exhibited notable proline accumulation, indicative of a metabolic response counteracting the cold effects, resulting in better fruit stress acclimation. This treatment also preserved the peppers’ color and antioxidant capacity. In summary, these findings highlight the suitability of applying a combined Wax + M500 treatment as a highly effective strategy to enhance the CI tolerance of peppers and extend their postharvest life.

9 March 2020 in Food Additives & Contaminants: Part B
Verified
Journal Article
Closed access
WEWania Espinoza
Wania Espinoza
PJPaul Vargas Jentzsch
Paul Vargas Jentzsch
FGFernando Gualpa
Fernando Gualpa
PAPaulette Andrade
Paulette Andrade
CMCarla Moreno
Carla Moreno
LRLuis Ramos
Luis Ramos
Clenbuterol is a steroid-type drug used in respiratory treatments in both humans and animals. However, it has a secondary effect related to the hypertrophy process in muscle and fat reduction. The illegal or bad use of clenbuterol has been reported in several countries, but there is scarce information in South America, where the production and consumption of meat are considerable. In this sense, the present study aimed at evaluating the occurrence of clenbuterol in bovine muscle and liver samples from a high cattle production area of Ecuador in 2015 and 2018. For this purpose, 57–58 samples were evaluated in 2015 and 20 samples in 2018 using the Enzyme-Linked Inmuno Sorbent Assay and ultrahigh-performance liquid chromatography-tandem mass spectrometry. The results showed complained results for clenbuterol in meat samples from both years and 23% (2015) and 85% (2018) of the samples of meat complied the maximum residue level defined by CODEX.

11 December 2025 in Horticulturae
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Journal Article
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Michelle GuijarroMichelle Guijarro
Michelle Guijarro
MDMagali Darré
Magali Darré
LCLudmila Careri
Ludmila Careri
Analía ConcellónAnalía Concellón
Analía Concellón
MZMaria Jose Zaro
Maria Jose Zaro
Eggplant is highly susceptible to chilling injury (CI) when stored at temperatures below 10 °C. This study evaluated the efficacy of glycine betaine (GB) as a pre-storage treatment to enhance chilling tolerance in eggplant, focusing on tissue-specific responses in the peel and flesh. GB concentrations of 0, 5, and 10 mM were tested, with 10 mM identified as the most effective in mitigating CI symptoms and weight loss. Subsequently, eggplants treated with 10 mM GB were stored for 21 days at 4 °C, followed by 2 days at 20 °C, to assess their physiological and biochemical properties. At the end of the storage period, GB treatment significantly reduced all CI-related indicators, including the CI index, weight loss, respiration rate, softening, flesh browning, electrolyte leakage, and malondialdehyde content, thereby extending shelf life by five days compared with untreated fruit. Principal component analysis revealed that severe CI in control fruit was associated with elevated levels of proline, endogenous GB, and unsaturated fatty acids (UFAs) in the peel, indicating that this outer tissue is the primary site of cold-stress responses in eggplant. Conversely, GB-treated fruit exhibited enhanced chilling tolerance characterized by reduced softening, greater antioxidant retention in both tissues, and maintenance of UFA levels in the flesh, while peel proline, GB, and fatty acid contents remained stable. Overall, our findings provide the first evidence that GB confers cold protection by modulating tissue-specific metabolic responses in eggplant peel and flesh, offering a simple and cost-effective strategy to extend shelf life.

13 May 2026 in Foods
Verified
Journal Article
Open access
PDF file
Michelle GuijarroMichelle Guijarro
Michelle Guijarro
MZMaria Jose Zaro
Maria Jose Zaro
Analía ConcellónAnalía Concellón
Analía Concellón
GMGemma Montalvo
Gemma Montalvo
FOFernando E. Ortega-Ojeda
Fernando E. Ortega-Ojeda
LRLuis Ramos
Luis Ramos
Eggplant (Solanum melongena L.) is highly susceptible to chilling injury (CI) during cold storage, with severity being strongly influenced by fruit maturity stage. At the tissue level, the peel acts as the primary site of cold-stress metabolic responses. This study evaluated the effect of pre-storage glycine betaine treatment (GB, 10 mM) on CI in purple eggplant at baby (BB, low sensitivity) and commercial (CC, high sensitivity) maturity stages stored at 4 °C for 20 days, integrating the use of ATR-FTIR spectroscopy as a rapid, non-destructive tool to monitor quality in the fruit peel. Physiological traits including chilling injury index (CII) and fruit rigidity were integrated with peel-specific ATR-FTIR spectroscopy combined with chemometric analysis to describe structural and metabolic behavior. BB fruit showed higher tolerance to CI, reaching a CII 23% lower than CC after 20 d, along with greater rigidity retention. GB treatment was significantly effective in reducing CI in both maturity stages by decreasing CII by 23% for BB and 32% for CC fruit, and delaying symptom onset. FTIR analysis revealed that the main peel spectral changes during storage occurred in the amide–phenolic (1653–1515 cm−1) and polysaccharide (~1017 cm−1) regions. Control fruit showed progressive shifts in these regions indicating structural disorganization, while GB-treated fruit delayed and attenuated spectral changes. Chemometric analysis (OPLS-DA) clearly discriminated samples according to maturity stage, treatment, and storage time. Overall, the results demonstrate that chilling susceptibility is determined by maturity stage, that the GB treatment enhanced CI tolerance—especially in sensitive CC fruit—and that ATR-FTIR coupled with chemometrics provides an effective approach for rapid non-destructive monitoring of postharvest quality changes in eggplant during cold storage.