Helena Nuñez

Mrs. Helena Nuñez


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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17 January 2022 in Catalysts
Verified
Journal Article
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ACAndrés Córdova
Andrés Córdova
PHPaola Henríquez Henríquez
Paola Henríquez Henríquez
HNHelena Nuñez
Helena Nuñez
FRFabián Rico-Rodriguez
Fabián Rico-Rodriguez
CGCecilia Guerrero
Cecilia Guerrero
Andrés IllanesAndrés Illanes
Andrés Illanes
The intensification of processes is essential for the sustainability of the biorefinery concept. Enzyme catalysis assisted by ultrasound (US) may offer interesting opportunities in the agri-food sector because the cavitation effect provided by this technology has been shown to improve the efficiency of the biocatalysts. This review presents the recent advances in this field, focused on three main applications: ultrasound-assisted enzymatic extractions (UAEE), US hydrolysis reactions, and synthesis reactions assisted by US for the manufacturing of agri-food produce and ingredients, enabling the upgrading of agro-industrial waste. Some theoretical and experimental aspects of US that must be considered are also reviewed. Ultrasonic intensity (UI) is the main parameter affecting the catalytic activity of enzymes, but a lack of standardization for its quantification makes it unsuitable to properly compare results. Applications of enzyme catalysis assisted by US in agri-foods have been mostly concentrated in UAEE of bioactive compounds. In second place, US hydrolysis reactions have been applied for juice and beverage manufacturing, with some interesting applications for producing bioactive peptides. In last place, a few efforts have been performed regarding synthesis reactions, mainly through trans and esterification to produce structured lipids and sugar esters, while incipient applications for the synthesis of oligosaccharides show promising results. In most cases, US has improved the reaction yield, but much information is lacking on how different sonication conditions affect kinetic parameters. Future research should be performed under a multidisciplinary approach for better comprehension of a very complex phenomenon that occurs in very short time periods.

22 December 2020 in Journal of Food Process Engineering
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Journal Article
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NRNatalia Ramírez
Natalia Ramírez
OVOscar Vega‐Castro
Oscar Vega‐Castro
RSRicardo Simpson
Ricardo Simpson
CRCristian Ramírez
Cristian Ramírez
HNHelena Nuñez
Helena Nuñez

1 November 2020 in Food Research International
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Journal Article
Closed access
HNHelena Nuñez
Helena Nuñez
GCG. Cavada
G. Cavada
CRC. Ramírez
C. Ramírez
Jorge MorenoJorge Moreno
Jorge Moreno
GCG. Cornejo
G. Cornejo
RSR. Simpson
R. Simpson

17 September 2021 in Foods
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Journal Article
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MCMatias Fardella Cisternas
Matias Fardella Cisternas
CRCristian Ramírez
Cristian Ramírez
ECEduardo Caballero-Valdés
Eduardo Caballero-Valdés
ESElizabeth Sánchez
Elizabeth Sánchez
MPMarlene Pinto
Marlene Pinto
RSRicardo Simpson
Ricardo Simpson
Furan and its derivates are present in a wide range of thermally processed foods and are of significant concern in jarred baby and toddler foods. Furan formation is attributed to chemical reactions between a variety of precursors and a high processing temperature. Also, some kinetic models to represent its formation in different food materials have been studied and could predict the furan formation under simulated operating conditions. Therefore, this review aims to analyze and visualize how thermally processed foods might be improved based on optimal control of processing temperature and package design (e.g., retort pouches) to diminish furan formation and maximize quality retention. Many strategies have been studied and applied to reduce furan levels. However, an interesting approach that has not been explored is the thermal process design based on optimum variable retort temperature profiles (VRTPs) and the use of retortable pouches considering the microstructural changes of food along the process. The target of process optimization would be developed by minimizing the microstructural damage of the food product. It could be possible to reduce the furan level and simultaneously preserve the nutritional value through process optimization.

19 January 2022 in Food and Bioprocess Technology
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Journal Article
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EAEric Araya
Eric Araya
HNHelena Nuñez
Helena Nuñez
NRNatalia Ramírez
Natalia Ramírez
AJAldonza Jaques
Aldonza Jaques
RSRicardo Simpson
Ricardo Simpson
CRCristian Ramírez
Cristian Ramírez

29 May 2023 in Foods
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Journal Article
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HNHelena Nuñez
Helena Nuñez
AJAldonza Jaques
Aldonza Jaques
KBKaryn Belmonte
Karyn Belmonte
ACAndrés Córdova
Andrés Córdova
GLGerman Lafuente
German Lafuente
CRCristian Ramírez
Cristian Ramírez
This research studied the use of CO2 LASER microperforation as a pretreatment for the refractive window (RW) drying of apple slices with respect to total polyphenol content (TPC), antioxidant capacity, color ΔE, and product stability under accelerated storage. For this purpose, the processing variables assessed were pore size (200–600 µm), pore density (9–25 pores/cm2), and drying temperature (70–90 °C). As baseline criteria, a comparison with respect to the control without microperforations and samples subjected to conventional tunnel and lyophilization were also considered. The increase in the pore size from 200 to 600 µm resulted in shorter drying times (≤40 min), minimal change in color (ΔE) and loss of TPC, while DPPH was negatively affected by the combined effect of the pore density and the drying temperature. In general, the use of RW with CO2 resulted in apples of higher quality than those obtained in conventional drying and comparable to those obtained through the use of freeze-drying. Finally, during accelerated storage, quality attributes decreased significantly for samples dried at 90 °C regardless of whether microperforations were used, suggesting that a compromise between drying temperature and pore size must be weighed to reduce processing time and to avoid further quality losses during storage.