Browsing by Author "Aguilera, Jose Miguel"

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    Development of food and gastronomy in the sub-Antarctic end of the world
    (2024) Aguilera, Jose Miguel; Rozzi, Ricardo
    Regional food and gastronomy flourish worldwide driven by unique local foods, the remembrance of old culinary traditions, and the visitors' desire to taste memorable dishes in an environment evoking cultural heritage and geographical uniqueness. The sub-Antarctic Magellan region of Chile is the southernmost zone of the planet and is unique in centenary food and culinary practices. A detailed description of marine and terrestrial local food sources and biocultural traditions is documented. This article presents a PCF to develop local food and gastronomy in this region. Collection and analysis of bibliometric data led to three pillars supporting the FPC: the nutritional value and uniqueness of local foods and culinary traditions; a booming sustainable tourism that drives the development of gastronomic endeavors, and; lessons from past experiences in other remote places. The proposed PCF may be adapted to different regions worldwide. Recent gastronomic initiatives to implement this PCF at the Cape Horn International Center in Puerto Williams (Chile) are also described.
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    Effect of cysteine addition and heat treatment on the properties and microstructure of a calcium-induced whey protein cold-set gel
    (2019) Lavoisier, Anais; Vilgis, Thomas A.; Aguilera, Jose Miguel
    A model gel of whey protein isolate (WPI) was prepared by cold gelation with calcium. This system was modified by the addition of free cysteine residues (Cys) at different steps of the process. The WPI cold-set gels obtained were then subjected to heat treatment at 90 degrees C. First, the effect of Cys addition on the heat-induced aggregation of WPI was studied through Atomic Force Microscopy (AFM) and infrared spectroscopy (ATR-FTIR), while Cys' effect on cold gelation was observed by AFM, Confocal Laser Scanning Microscopy (CLSM) and oscillatory rheology (amplitude sweeps). The impact of heating on the microstructure and the viscoelastic properties of the WPI cold-set gels were finally investigated through several techniques, including DSC, ATR-FTIR, CLSM, cryo-SEM, and rheological measurements (temperature sweeps). When added during the first step of cold gelation, Cys modified heat-induced aggregation of WPI, resulting in the formation of a denser gel network with a fractal dimension (Df) of 2.8. However, the addition of Cys during the second step of cold gelation led to the formation of highly branched clusters of WPI and a looser gel network was observed (Df = 2.4). In this regard, the use and limitations of oscillatory rheology and the "Kraus model" to determine the Df of WPI cold-set gels was discussed. The viscoelastic properties and the microstructure of the WPI cold-set gels were irreversibly modified by heating. Gels were stiffer, more brittle, and coarser after heat treatment. New disulfide bonds and calcium bridges formed, as well as H-bonded beta-sheets, all contributing to the formation of the final gel network structure.
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    Effects of cooking on the composition of volatiles, total phenolic compounds, and antioxidant capacity of three Chilean seaweeds
    (2023) Figueroa, Valentina; Holdt, Susan Lovstad; Jacobsen, Charlotte; Aguilera, Jose Miguel
    Seaweed consumption is increasing around the world due to consumer demands for sustainable food sources, health benefits derived from bioactive compounds, and a source of novel flavors. Despite all the benefits that come with eating seaweed, consumers still resent of their sensorial properties. Seaweed is traditionally consumed raw or cooked, but there is still not enough information on how the sensory descriptors and bioactive compounds change when cooked. The aim of this study was to determine the change in total polyphenol content (TPC), antioxidant capacity (e.g., DPPH and ORAC values) and changes in volatile compounds of three Chilean seaweeds: Durvillaea antarctica, Pyropia spp. and Ulva lactuca when subjected to traditional cooking for 15 min at 100 degrees C. In all three seaweeds, TPC decreased with cooking and so did the measured antioxidant capacity. Altogether, 46 volatile cpmpounds were identified in D. antarctica, 49 in Pyropia spp. and 47 in U. lactuca. The concentration of these volatile compounds was correlated with aroma sensory descriptors of the same samples. Consumer preferences may be attracted by the herbal notes of U. lactuca or the sweet, caramel, and umami flavors of D. antarctica and Pyropia.
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    Natural laboratories in emerging countries and comparative advantages in science: Evidence from Chile(sic)(sic)(sic)Palabras clave
    (2021) Aguilera, Jose Miguel; Larrain, Felipe
    Entering the knowledge society and mobilizing science and technology are critical for emerging countries (ECs) to address important challenges of society and promote long-term economic growth. Natural laboratories (NLs) are geographical or geophysical singularities that provide comparative advantages and leverage to ECs for scientific research and international collaboration. Based on empirical evidence and learning experiences from five NLs in Chile, we propose the foundations of a conceptual framework for public scientific policies based on NLs and their possible implementation in ECs. Scientific research in NLs may address local, national, and global societal challenges while decentralizing scientific activities, encouraging transdisciplinary research in territories, anticipating the effects of climate change, and protecting biodiversity while promoting international partnerships and alignment with 2030 Sustainable Development Goals.
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    Quantification of fracture properties and microstructural features of roasted Marcona almonds by image analysis
    (ELSEVIER SCIENCE BV, 2008) Varela, Paula; Aguilera, Jose Miguel; Fiszman, Susana
    A method to quantify fracture pattern and microstructural heat damage through image analysis was proposed. The microstructure of Marcona almonds with different degrees of roasting (200 degrees C; 0, 1.5, 3, 4.5, 6 min) was related with their compression and fracture behaviour. Mechanical tests were performed with a TAXT2 texture analyser. The fracture pattern was characterized by measuring the particle size distribution with image analysis after compression. Light microscopy (LM) and scanning electron microscopy (SEM) were used to observe the changes in the microstructure of the almonds during roasting. The use of image analysis to quantify micro- and macro-structural features proved to be a very useful tool for analysing the crispness/crunchiness behaviour of the samples. The disruption of the inner parenchyma in the samples roasted for longer times proved to be the principal cause of their increased brittleness. The heterogeneity caused by heat degradation contributed to the failure of the material under compression, changing it from a deformable hard solid (raw sample) to a brittle one with enhanced crispy/crunchy characteristics. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.
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    Seligman Lecture 2005 - Food product engineering: Building the right structures
    (WILEY, 2006) Aguilera, Jose Miguel
    Driven by consumers' expectations and new knowledge, a paradigmatic shift is occurring in food engineering from the prior emphasis in processes and unit operations to the design of products that provide convenience, health and well-being. The structure of foods affects their sensorial, physical and transport properties as well as the bioavailability of some nutrients. Food structure is provided by nature or imparted during processing and preparation. Presently, food product engineering is stabilizing, transforming and creating edible microstructures that are desired by consumers using conventional unit operations. This paper revises the progress in the science of food materials and its contribution to the understanding of how food structures are formed from the molecular to the macromolecular level. Food product design of the future will be based on a wider scientific knowledge adopted from many disciplines and advanced tools that reduce the scale of fabrication. This poses a challenge to food engineering education. (c) 2006 Society of Chemical Industry