Browsing by Author "Fredes, Carolina"
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- ItemChilean native species as source of natural polyphenols(CABI, 2013) Fredes, Carolina; Montenegro, Gloria; Céspedes, Carlos L.; Sampietro, Diego A.; Sigler, David; Rai, MahendraThis chapter discusses the traditional uses of native medicinal plants from Chile and provides tabulated data on Chilean medicinal plants, including the parts used and their effects, in order to analyse compounds that could be responsible for these medicinal effects. It presents scientific evidence supporting biological activity associated with the presence of polyphenols in Chilean plants. The determination of polyphenols in Chilean plants and their antioxidant capacity are described. The main factors affecting polyphenol content in plants are also mentioned, i.e. genotype, environment, storage and processing, and stage of harvest.
- ItemComparison of volatile compounds in Retanilla trinervia [Gillies & Hook] Hook & Arn honeys from central Chile(2015) Montenegro, Gloria; Santander, Francisca; Nunez, Gabriel; Fredes, CarolinaThe search for chemical markers for determining honey authenticity as a complementary tool for melissopalynological method is an important issue in the study of honeys from different botanical origins. The objective of this study was to determine the volatile compounds in tevo (Retanilla trinervia [Gillies & Hook] Hook & Arn [Fam. Rhamnaceae]) honey as one of the most relevant honeys from central Chile. For the identification and quantification of volatile compounds, Solid-Phase Microextraction and Gas Chromatography with Mass Spectrometry (SPME-GC-MS) was performed. A total of 28 out of 103 volatile compounds were found common to the five tevo honeys analyzed. Nevertheless, these compounds are common in unifloral honey of different floral sources from other countries. These results represent the first record in the identification of volatile compounds in tevo honey and would indicate that tevo honey does not present specific volatile compounds that allow its clear differentiation from other unifloral honey.
- ItemCONTENT OF HEAVY METALS IN SOILS NEAR A CHILEAN COPPER MINING TAILING(2009) Montenegro, Gloria; Fredes, Carolina; Mejias, Enrique; Bonomelli, Claudia; Olivares, LuisIn Chile, heavy metals pollution occurs mainly near copper mines in the northern and central regions of the country. Here, agricultural soils have been found to be polluted by heavy metals several kilometers from the source. The objective of this study was to analyze the contents of Fe, Cu, Mn, Zn, Cr, Cd and Pb and chemical variables (pH, EC, OM and CEC) of soils found near copper mine tailing in the north of the country. Available heavy metals were determined using AAS, and total heavy metals were determined with ICP-OES. Soils were grouped into three sectors, according to their proximity to the tailing, the course of an estuary, and the direction of the wind. Cu was the heavy metal found in the highest average concentrations relative to the rest of the elements determined. The samples that followed the course of the estuary had the highest average contents of Cu, with significant (p <= 0.05) statistical differences from the other sectors. Principal components analysis of the heavy metal contents of the 24 samples analyzed indicated that three principal components explained 75.5% of the data variability. In the dispersion graph of the first two components, a group of soils close to the interception axis and four distant soils, which had the highest contents of Fe (276.6 mg kg(-1)), Cu (375.1 mg kg(-1)), Mn (56.7 mg kg(-1)), Zn (21.7 mg kg(-1)), Cr (45.0 mg kg(-1)) and Pb (129.3 mg kg(-1)), are observed.
- ItemPhenolic profiles of nectar and honey of Quillaja saponaria Mol. (Quillajaceae) as potential chemical markers(2013) Montenegro, Gloria; Rodríguez, Sharon; Fredes, Carolina; Díaz-Forestier, JavieraQuillaja saponaria Mol. (Quillajaceae) is one of the most important melliferous species in Chile, mainly as a source of monofloral honey. Honey made by A. mellifera presents biological activity against pathogens and antioxidant capacity associated with the presence of phenolic compounds deriving from the nectar, as a result of bee honey foraging. The aim of this study was to identify and quantify the phenolic compounds from the floral nectar of Q. saponaria and the honey made in apiaries in the central zone, and compare the composition of the chromatographic profiles of nectar and honey to known phenolic compounds. The results obtained by HPLC-DAD (high-performance liquid chromatography with diode-array detection) showed a similar profile of phenolic compounds, in which gallic acid, myricetin, rutin, quercetin and naringenin were identified. The phenolic compounds detected could be used as a reference for future studies for determining potential chemical markers of this honey, complementing the present identification of honeys by determining their botanical origin. The identification of bioindicators of the floral origins for honey of this species could provide added value to honey commercialization by certifying the botanical origin of their chemical features and biological attributes.
- ItemPredicting academic success in undergraduate students from the Nutrition and Dietetics degree program from the Pontificia Universidad Católica de Chile(2024) Pettinelli, Paulina; Fernandez-Verdejo, Rodrigo; Fredes, Carolina; Parada, Alejandra; Aguirre, CarolinaIntroduction: Identifying the factors that determine academic success can help design strategies focused on increasing academic success. We aimed to identify predictors associated with academic success in undergraduate students of the Nutrition and Dietetics Program of the Pontificia Universidad Cat & oacute;lica de Chile (PUC). Methods: Retrospective study using the institutional database. Academic success was the main outcome, including two indexes: i) final grade point average (GPA-f) and; ii) timely graduation, defined as graduating in <= 10 semesters. Candidate predictors were: age, sex, region of origin, school attended, score at the university selection test (PSU-score), admission route, and preference for the program. Stepwise linear regression was used to identify predictors of GPA-f. Binary logistic regression was used to identify variables associated with timely graduation. Results: PSU-score was the only predictor of GPA, explaining 24% of its variance. The odds (OR [95%CI]) for a timely graduation were influenced by PSU-score (1.017 [1.003- 1.031]) and admission route (PSU 1.00 [Reference], Inclusive 0.30 [0.10- 0.96], Special 0.46 [0.13- 1.57]). Conclusions and implications: PSU-score partially predicts the academic success of Nutrition and Dietetics students. In addition, students who accessed the program by the equity admission had lower odds of a timely graduation. As educational inequalities may affect academic success, the teaching and learning process needs to be addressed with specific strategies for these students to ensure academic success.
- ItemRecovery of Bioactive Compounds from Pomegranate (Punica granatum L.) Peel Using Pressurized Liquid Extraction(2021) Garcia, Paula; Fredes, Carolina; Cea, Ines; Lozano-Sanchez, Jesus; Javier Leyva-Jimenez, Francisco; Robert, Paz; Vergara, Cristina; Jimenez, PaulaPressurized liquid extraction (PLE) is a clean and environmentally friendly alternative for the recovery of bioactive compounds from fruit by-products. Herein we focused on PLE for the extraction of bioactive compounds from pomegranate peel using a combination of pressurized water and ethanol. The main aim was to determine the optimal PLE conditions, i.e., ethanol percentage and process temperature, to obtain a pomegranate peel extract (PPE) with maximum total phenolic content (TPC), punicalagin content, and antimicrobial activity (AMA). The experimental design was conducted using a central composite design with axial points. Response surface methodology was applied to optimize the response variables using the desirability function. Multiple response optimization indicated a process temperature of 200 degrees C and ethanol of 77% as optimal conditions. The TPC and the punicalagin content of PPE-PLE obtained under optimal conditions were 164.3 +/- 10.7 mg GAE/g DW and 17 +/- 3.6 mg/g DW, respectively. Our findings support the efficacy of PLE on TPC recovery but not in punicalagin recovery. The AMA against S. aureus was 14 mm. The efficacy of PPE-PLE in food applications must continue to be studied in order to achieve adequate information on its potential for developing new food additives.
- ItemThe powerful colour of the maqui (Aristotelia chilensis [Mol.] Stuntz) fruit(2014) Fredes, Carolina; Robert, PazOver the past 10 years, the research interest on maqui has increased due to the potential health benefits of the fruit, which are largely attributed to the high anthocyanin content and high antioxidant capacity. Furthermore, maqui fruit has earned the name of ‘superfruit’, and several products based on the dehydrated fruit and maqui juice are available on the international market. Although the maqui fruit is not frequently consumed by the Chilean population from urban areas, its use is deeply rooted in rural and native cultures (Mapuche and Huilliche). This review summarises the validation of the traditional uses of maqui and new evidence highlighting the principal role of anthocyanins in the antioxidant, anti-inflammatory and anti-diabetic activity of maqui fruit. The identification of a particular anthocyanin (delphinidin-3-glucoside-5-sambubioside) in maqui fruit and its anti-diabetic effect in in vivo models, in addition to its presence at higher concentrations in some maqui genotypes, encourages investigation into maqui genotypes that may have higher contents of particular anthocyanins. However, information concerning maqui domestication is still deficient.
- ItemWe Only Collect What We Need: Women's Experiences on Collecting Cauchao (Amomyrtus luma Molina) in Food Systems of Extreme South Forests in Chile(2024) Fredes, Carolina; Parada, Alejandra; Aguirre, Carolina; Rojas, Loreto; Robert, Paz; Bernales, MargaritaThe collection of the ancestral fruit cauchao (Amomyrtus luma) is part of the routines of women gatherers from the extreme south (44 degrees South Latitude) in Chile. The traditional food knowledge of cauchao has not been documented, and there is no data on the nutritional composition. Women's experiences collecting cauchao can help understand the relationship between traditional food, herbal medicine, and local gatherers' communities. Thus, this research explores the traditional knowledge of food and the nutritional composition of cauchao. Mixed methods research was performed. A case study included in-depth interviews with 12 women gatherers and thematic analysis. The composition of macronutrients in cauchao was obtained by proximate chemical analyses and dietary fiber using the enzymatic-gravimetric method. Results showed that gathering for these women was more than just extracting natural resources; it was associated with family, food security, participation in different stages of the food system, and practices that could contribute towards sustainable food systems. Furthermore, cauchao fruit showed a high dietary fiber content, and women gatherers did not connect cauchao with dietary fiber. Since access to knowledge by small-scale food producers, especially women, is part of the Sustainable Development Goals (SDG#2.3), the approach of this research may help guide knowledge transfer among women gatherers.