Browsing by Author "AGUILERA, JM"

Now showing 1 - 7 of 7
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    A KINETIC INTERPRETATION OF TEXTURAL CHANGES IN BLACK BEANS DURING PROLONGED STORAGE
    (1987) AGUILERA, JM; BALLIVIAN, A
    Control and roasted (80.degree.C), dry black beans (Phaseolus vulgaris) were stored for 9 months at 8, 10, 12, and/or 14% moisture content and 8.5.degree., 25.degree., and 40.degree.C. Similarly, beans heated in a solid-to-solid roaster to 51.degree., 61.degree., 72.3.degree., 80.degree., 85.5.degree., 89.5.degree., 101.degree., and 111.degree.C were maintained at 8% moisture and 25.degree.C. Final hardness increased with moisture content and temperature. Hardening at 8.5.degree. and 25.degree.C proceeded initially almost linearly reaching a constant value after 4 to 6 months while at 40.degree.C it was sigma-shaped. A pseudo-zero order kinetic model fitted for initial rates had an activation energy of 6-11.8 kcal/mol. The hardening rate at 25.degree.C paralleled the shape of the sorption isotherm.
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    CHARACTERISTICS OF GUINDILLA (VALENZUELA-TRINERVIS BERT) OIL
    (1986) AGUILERA, JM; FRETES, A; SANMARTIN, R
    Seed of Guindilla (Valenzuela trinervis Bert.) and its oil were characterized. On a dry weight basis, the seed consists of 56% hull and seed coat and 44% cotyledon, containing about 67.0% lipids. The main fatty acids are: 62.3% oleic, 12.9% gadoleic, 10.1% linoleic and 9.6% palmitic. Physical properties of oil, expressed by hand press, include: melting point, -6 to -2 C; iodine value, 75.1; saponification value, 192; and unsaponifiable matter, 0.8%.
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    ETHANOL EXTRACTION OF RED-PEPPER - 3 KINETIC-STUDIES AND MICROSTRUCTURE
    (1987) AGUILERA, JM; ESCOBAR, GA; DELVALLE, JM; MARTIN, RS
    A three-parameter kinetic equation was developed for ethanol extraction of oleoresin from dry red peppers under different solute to solvent ratios, particle sizes and condition of structural damage. The model distinguished two main mechanisms of extraction: a fast, washing step and a diffusion-controlled process. Flaking and, to a lesser extent, blanching induced significant cellular damage resulting in more oleoresin being washed, a faster extraction rate and a higher final concentration in the solvent, compared to untreated material. The activation energy for extraction derived from the study was 6.1 kcal/mol, typical of diffusion-controlled processes. Light micrographs related microstructure to variations in extraction parameters.
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    FOOD, AGRICULTURAL AND MARINE BIOTECHNOLOGY IN CHILE
    (ELSEVIER SCIENCE BV, 1993) AGUILERA, JM; AGOSIN, E; MARTIN, RS
    Economic segments with highest growth rates in Chile are those based on renewable resources like agriculture (fruits and vegetables), marine and forest products. Opportunities for biotechnology are based on a sound scientific base at universities, adequate funding and incipient industry-academia relationships. However, there is an urgent need to develop the engineering capabilities required to scale-up processes and to design, build and operate industrial biotechnology plants.
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    PHYSICOCHEMICAL CHARACTERIZATION OF RAW FISH AND STICKWATER FROM FISH-MEAL PRODUCTION
    (1991) DELVALLE, JM; AGUILERA, JM
    Chemical and microbiological properties of raw fish (RF) and chemical properties of stickwater (SW) samples were studied as a function of the staleness level of the fish. As time elapsed from fish capture increased, the microbial count in RF, volatile nitrogen content in RF and SW, and dissolved solids and dissolved protein in SW, increased. The apparent viscosity of SW increased as the temperature decreased and as the dry solids or suspended matter content increased. The size distribution of suspended particles in SW depended on the sample preparation technique, method used to measure particle size and whether the size distribution was expressed in terms of the weight or population of fractions. The average size (by weight) of suspended solids in SW was 2.5-mu-m as estimated by electronic counting. The solubility of protein in SW decreased when acid or alkali were added or thermal treatment (1 h at 90-degrees-C) applied. A minimal solubility point occurred near pH 5. The molecular weight of most dissolved proteins in SF was 3 kD. SF also contained a small proportion of 67 kD proteins. The significance of this basic characterisation study for the selection of improved processes for stickwater recovery is discussed.
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