Abstract Recently a surface plasmon resonance (SPR) optical sensor, based on the Otto configuration — the Otto chip — has been developed. One essential step in the quality control of the fabrication process is characterization of the active region of several devices in a batch. Characterization is done by measuring the angular spectrum of the optical re ectance on several points across the active region of the device, and determining parameters by regression analysis of the data. Traditional gradient methods used in the regression process are extremely dependent on an initial guess and are not very efficient for batch analysis of curves, when those include poorly defined SPR spectra, where an initial guess may be hard to infer. An alternative approach for the regression problem is to model the analysis as an optimization problem and using an efficient stochastic algorithm. In this paper one discusses the use of Particle Swarm Optimization (PSO) for characterization of Otto chip devices. From comparative studies carried out in an existing Otto chip, it is observed that PSO can be a very efficient approach for batch analysis and yields better results when compared with the traditional gradient-based regression method.

Abstract Rabbit meat has a low-fat content when compared to other meat traditionally used as raw material in the processing of fermented sausages. In addition, it has high levels of essential amino acids in its composition. Thus, the objective of this study was to evaluate the technological properties and sensorial acceptance of a fermented sausage produced with pork and rabbit meat. Three formulations were made: C1 (80% fresh lean pork + 20% pork back fat), T1 (40% fresh lean pork + 40% rabbit meat + 20% pork back fat) and T2 (80% rabbit meat + 20% pork back fat). Samples were evaluated for composition, texture profile, instrumental color, pH, weight loss, lipid oxidation and sensorial acceptance. The samples did not present significant differences between them for moisture, fat and protein contents. Regarding the aroma, flavor, hardness and overall acceptance, all samples presented similar mean values (P>0.05). The study showed that up to 40% of rabbit meat could be substituted in a fermented pork sausage without altering any of the sensorial attributes evaluated and with minimal effect on the technological parameters.