Analysis of experimental biosensor/FIA lactose measurements

Abstract

Whey is an abundant effluent in the production of cheese and casein. The biotechnological utilization of this economically important and nutritive source is limited mainly because of the presence of high percentages of lactose. This disaccharide has poor solubility, which can cause crystallization and insufficient sweetness in dairy food; additionally, part of the adult population suffers from associated lactose intolerance diseases. There are several methods to determine lactose such as spectrophotometry, polarimetry, infrared spectroscopy, titrimetry and chromatography. However these methods are tedious and time-consuming due to long sample preparation. These disadvantages stimulated the development of an enzymatic lactose biosensor. It employs two immobilized enzymes, beta-galactosidase and glucose oxidase and the quantitative analysis of lactose is based on determination of oxygen consumption in the enzymatic reaction. The influence of temperature on the biosensor signal was experimentally studied. It was observed that a nonlinear relationship exists between the electric response of the biosensor - provided by CAFCA (Computer Assisted Flow Control & Analysis - ANASYSCON, Hannover) - and lactose concentration. In this work, attempts were made to correlate these variables using a simple nonlinear model and multilayered neural networks, with the latter providing the best modeling of the experimental data

Hydrolysis of whey lactose by immobilized β-Galactosidase

“…Lactose use in nutritious products is limited because of low solubility, low sweetener power and laxative effect, if consumed in high concentration (Ferreira et al, 2003). The hydrolysis of lactose in glucose and galactose by β-galactosidase is one important process in the food industry, due to the potentially beneficial effects on assimilating the foods containing lactose, as well as the technological and environmental advantages of industrial applications (Jurado et al, 2002):…”

Biosensor and its Application in Food and Dairy Industry: A Review

“…Horseradish peroxidase (POD) oxidizes H 2 O 2 with 5-ASA (aminosalicyclic acid) as a mediator. The oxidized form of the mediator is reduced at the electrode resulting in an amperometric signal proportional to the lactose concentration (Ferreira et al, 2003) …”

Soft Computing Techniques in Modelling the Influence of pH and Temperature on Dopamine Biosensor

“…It is well known that neural networks are universal function approximators (Blum & Li, 1991). The approximation possibility of feedforward multilayered neural networks with backpropagation learning algorithm for modelling the biosensor's output voltage versus substrate concentration at different temperatures has been considered in (Ferreira et al, 2003). The same type of neural network has been used for pH estimation (Hitzman et al, 1997;Moatar et al,1999) and control (Lamanna et al, 1996;Syu & Chen, 1998) with applications in ecology.…”