Jorge Saavedra

Influence of agroclimatic parameters on phenolic and volatile compounds of Chilean virgin olive oils and characterization based on geographical origin, cultivar and ripening stage

BACKGROUND This study involved two commercial orchards located in Limarí Valley and Molina from two important Chilean production zones of extra virgin olive oil (EVOO). The investigation evaluated the effects of climate, soil composition, agricultural practices (fertilization and irrigation) and variety (considering two harvests) on the compounds responsible for the flavor of EVOO (volatiles and phenols) and how these compounds can explain the differences in chemical profiles by geographical origin, cultivar and fruit ripeness stage. RESULTS Varieties from the Limarí Valley presented the highest content of phenolic compounds. A significant relationship (P < 0.05) between volatile compounds and climate indicated that the compounds produced via the lipoxygenase cascade were affected by the maximum temperature and, to a lesser extent, by evapo-transpiration and irrigation. The selection of different individual phenolic and volatile compounds independently allowed the significant differentiation of EVOOs, principally by geographical origin, crop season, fruit ripeness stage and, in a few cases, by cultivar. CONCLUSION Soil and climate of the Chilean regions have much more influence than cultivars on the concentration of sensory quality compounds. Difference in latitude between orchards increases the importance of the geographical origin on the virgin olive oil chemical composition while full irrigation decreases the impact of the cultivar.

Microencapsulation of pulp and ultrafiltered cactus pear (Opuntia ficus-indica) extracts and betanin stability during storage.

Pulp (CP) and ultrafiltered (UF) cactus pear extracts were encapsulated with Capsul (C) by applying a central composite design (CP-C and UF-C systems) by spray-drying. To evaluate the effect of the extract, microparticles obtained under optimal conditions were characterised and stored at 60 °C. Betacyanin and betaxanthin encapsulation efficiency reached values above 98% for both systems studied. This efficiency was attributed to strong interactions between betalains and the polymer. Betalain degradation in CP-C and UF-C microparticles followed pseudo-first order kinetics. The betacyanin degradation rate constant was significantly higher for CP-C than for UF-C. These results suggested that the mucilage or higher sugar content of CP increased the hygroscopicity of the CP-C microparticles, leading to the degradation of betalain. The hydrolysis pathway was the main mechanism of betanin degradation during microparticle storage. These results demonstrate the potential utility of both CP-C and UF-C microparticles as natural colourants for healthy foods.

Chemometric Analysis for the Detection of Biogenic Amines in Chilean Cabernet Sauvignon Wines: A Comparative Study between Organic and Nonorganic Production

UNLABELLED In this work, the presence of biogenic amines (BAs) was correlated with the type of wine grape culture (traditional or organic) and their concentration in the different stages of winemaking (must, alcoholic fermentation [AF] and malolactic fermentation [MLF]). The formation of BA occurred mainly during MLF in which the percentages for putrescine, cadaverine, phenylethylamine, histamine, and tyramine were 100%, 70%, 13%, 61%, and 44% for the wines produced with traditional grapes and 100%, 94%, 25%, 88%, and 13% for the wines produced with organic grapes, respectively. In general, these latter wines exhibited a lower concentration of total amines. The principal component analysis and partial least-square discriminate analysis indicated that the generation of BA has a certain behavioral pattern in the wines analyzed, which is associated with the different stages of wine production and with the type of culture (traditional or organic) used in the wine grapes. PRACTICAL APPLICATION Chemometrics tools can be useful as a method of characterization and classification in a global overview of the process variables involved in the development of toxic chemicals in foods, such as the production of BA in wine.

Preharvest Interval Periods and their relation to fruit growth stages and pesticide formulations

The aim of this study was to evaluate the effect of pesticide formulations and fruit growth stages on the Pre-harvest Interval Period (PHI). Results showed that pesticide formulations did not affect the initial deposit and dissipation rate. However, the fruit growth stage at the application time showed a significant effect on the above-mentioned parameters. Fruit diameter increases in one millimeter pesticide dissipation rates were reduced in -0.033mgkg-1day-1 (R2=0.87; p<0.001) for grapes and -0.014mgkg-1day-1 (R2=0.85; p<0.001) for apples. The relation between solar radiation, air humidity and temperature, and pesticide dissipation rates were dependent on fruit type. PHI could change according to the application time, because of the initial amount of pesticide deposit in the fruits and change in the dissipation rates. Because Maximum Residue Level are becoming more restrictive, it is more important to consider the fruit growth stage effects on pesticide when performing dissipation studies to define PHI.

Effect of polyunsatured aldehyde (A3) as an antiparasitary ingredient of Caligus rogercresseyi in the feed of Atlantic salmon, Salmo salar

Some polyunsaturated aldehydes (PUAs) such as 2-trans, 4-trans decadenial (A3) have a detrimental effect on the development of copepod sharmful to the salmon industrysuch as Caligus rogercresseyi (sea lice). The purpose of this study was to evaluate the potential use of A3 as a salmon feed ingredient in order to reduce reproduction of Caligus rogercresseyi in infested Atlantic salmon (Salmo salar). The toxicity of A3 was assessed histopathologically for 7 days, using intra-peritoneal injections of different doses (0, 0.24, 0.47, 2.37, 11.86, and 23.71 mg kg -1 ) in brain, intestine, skin, liver, and muscletissues of Salmosalar at the end of each treatment. The effect of A3 on sea lice was evaluated using 250 Atlantic salmon in an open-flow system of seawater (~13°C). The effect of the dosage in the fish diet was evaluated at two levels (9 mg kg -1 , 18 mg kg -1 ) and considering a control (without A3) for 4, 8, and 12 days, once the sea lice had reached maturity. As a complement, the persistent effect of diluted A3 in sea water (0.5 g L -1 ) was evaluated at 10, 12, and 14°C for 0, 1, 3, 6, 10, and 15 days; and the maximum persistence was found at 10 days at 10°C. The results showed that the dosages over 0.47 mg kg -1 had no toxic effect on Atlantic salmon, but induced a detrimental effect on Caligus rogercresseyi (reduction of 15% of mature females with a dose of 18 mg kg -1 ), which could be attributed to alterations in the embryonic development of the sea lice. A3 is a potential supplement in the diet of salmon. However, studies ofits mechanism of action should be undertaken prior to its use.

Automatización de un Secador Convectivo de Aire Caliente para fines de Docencia en Ingeniería de Alimentos

This paper describes the design and installation of an automated experimental device applied to a parallel co-current hot air dryer to perform drying studies in the field of food engineering. The development of this work was divided into two main activities: (i) design of the automation system and (ii) validation of automatically collected data. A device capable of collecting and registering real time data and images from drying processes, and transmitting them through Internet was obtained. The data processed by the automatic device was statistically validated. It is concluded that the proposed automation device is feasible, reliable and attractive for the users, facilitating the teachinglearning process in an important area of Food Engineering.

Industrial prune processing and its effect on pesticide residue concentrations

The aim of this study was to determine the insecticide residue processing factor (PF) from plums to prunes and the effect of the industrial processing of prunes residue concentrations. Our results show an increase of insecticide concentrations during plum dehydration that is explained by fruit water loss; however, the normalized insecticide residue concentration, based on plum dry weights to compensate dehydration, was reduced. The water washing and tenderizing of prunes produced insecticide residue reductions of 22.9 ± 4.5% and 21.9 ± 4.2%, respectively. PF were: 1.157, 1.872, 1.316, 0.192, 2.198, 0.775 and 0.156 for buprofezin, l-cyhalothrin, spirodiclofen, indoxacarb, acetamiprid, imidacloprid and emamectin benzoate, respectively, being directly related to water solubility, aqueous hydrolysis and degradation point and inversely related to molecular mass and melting point. In plums for the dehydrated agroindustry the final product is prunes, therefore, it is crucial to consider the PF to determine the specific preharvest interval for this important agroindustry.

Effects of climate and anthocyanin variables on the zoning of Pinot Noir wine from the Casablanca Valley

The Casablanca Valley is one of the youngest wine grape regions of the Chilean appellation of origin. The growers of this area note the presence of microclimates within the valley as one of its main features. These microclimates have historically been associated with two geographical zones: the Zona Alta and the Zona Baja. The objective of this research was to explore the effects of climate variables and anthocyanin profiles in Pinot Noir wines of the Casablanca Valley as a differentiator of productive zones. The climate variables were measured using weather stations located at different points across the valley. Wine samples from the same locations were characterised according to their anthocyanin profiles. The data were processed using analysis of variance, principal components analysis and partial least squares discriminant analysis to determine differences between the two groups explored. The results indicate a strong correlation between variables and zones (98.3% R2Y), leading to the conclusion that there are significant differences between the Zona Alta and Zona Baja group. Finally, the existence of a vineyard that does not belong to the Zona Baja group suggests a reassessment should be performed of the vineyards belonging to the administrative areas defined as part of the Casablanca Valley.

Monitoreo y Análisis de un Proceso de Elaboración de una Bebida Carbonatada mediante 3-Way PLS

The present research deal with the modeling an analysis of a continuous soft-drinks bottling process by a multivariate approach based on the 3-Way PLS. For this purpose the process behavior was studied, related to a set of off-processing, transitions grades and/or abnormal star-ups, detected in four month process period. A total of 1938 cases were investigated, measuring 8 process variables. Finally, the process was modeled, filtering the high grade of autocorrelation and cross-correlation within the studied variables (particularly T1, T2 and T3). Thereby, the responsible variables for that behavior were detected; thus the effect and grade of disturbance over the process behavior and final product were estimated.