Lactose sensor

With a similar lactose sensor, Pilloton et al. (1987) assayed lactose in milk samples and obtained a good correlation with the reduction method described by Fehling. The enzyme was fixed to a nylon membrane. A cellulose acetate membrane (molecular cutoff 100 Dalton) was included in order to eliminate electrochemical interferences. The lifetime of the sensor was 1 month. 

Dosivit, Nantes, France MC2 Multisensor Glucose, sucrose, lactose, lactate, ethanol Electrochemical enzyme sensor Agriculture, food... 

The decomposition of polymer molecules in wastewater samples can also be achieved by a hybrid sensor, which consists of a consortium of microorganisms and hydrolases together. As an example, the BOD of lactose-containing wastewater was determined by a hybrid sensor consisting of cells of the yeast Lipomyces kononenkoae and of the enzyme /1-galactosidase [50, 69]. It is also possible to use a column containing immobilized enzymes, which is inserted in the measuring device (e.g., an FIA) before the biosensor [52, 70]. Such a combination of an enzyme column, which contains a-amylase and amy-... 

Electrochemical transducers work based on either an amperometric, potentio-metric, or conductometric principle. Further, chemically sensitive semiconductors are under development. Commercially available today are sensors for carbohydrates, such as glucose, sucrose, lactose, maltose, galactose, the artificial sweetener NutraSweet, for urea, creatinine, uric acid, lactate, ascorbate, aspirin, alcohol, amino acids and aspartate. The determinations are mainly based on the detection of simple co-substrates and products such as 02, H202, NH3, or C02 [142]. 

Several other sensors are available that are based on the amperometric measurement of hydrogen peroxide produced by enzymatic reactions. The analytes measured include sucrose, lactose, ethanol, and L-lactate. A different enzyme is, of course, required for each species. In some cases, enzyme electrodes can be based on measuring oxygen or on measuring pH. 

Sensors offer the possibility to realtime analysis, which is particularly important for the rapid analysis of samples. We have used sensors in a study to develop cheese starters. The action of the starter bacteria is central to the production of cheese. Their primary function is the production of the lactic acid from lactose which ensures the desired pH at all stages throughout the process. 

For the determination of AA, two non-enz3miatic sensors based on PANI-CNT composites were developed that differ from each other in the electrode composition. The catal ftic effect of copper nanoparticles (CuNPs] was utilized in one of the approaches [47] and the other was based on an electropolymerized poly(2,5-dimethoxyaniline]-NH2-MWCNT film [48]. Both sensors showed selective oxidation of AA in the presence of DA and UA at 0.4 and 0.28 V, respectively. The interference from 10 pM glucose, oxalic acid, fructose, lactose, NaCl, sucrose, and tartaric acid was negligible in 0.1MAA[47]. 

Other metabolites that have been measured with calorimetric sensors include ascorbic acid, ATP/ADP (adenosine 5 -diphosphate), cephalosporins, galactose, hydrogen peroxide, lactose, malate, phospholipids, uric acid, xanthine, and hypoxanthine. 

Rajendran, V. and Irudayaraj, J. 2002. Detection of glucose galactose and lactose in milk with a microdialysis-coupled flow injection amperometric sensor. J. Dairy Sci. 85 1357-1361. 

An alternative to power consumption is torque measurement. A high-shear mixer was instrumented with a new capacitive sensor, a watt meter, and a strain-gauge torque sensor (50). Placebo formulations containing DCP, MCC 101, MCC 102, and lactose were granulated in the high-shear granulator. A similar map (profile of torque measurement or power consumption) of the granulation process was obtained for power consumption and torque measurement. 

The acoustic emissions during the wet granulation of a model formulation containing lactose and MCC were monitored using acoustic emission sensors (58). The... 

Food and drink sensors. In the food and drink industries, quick and inexpensive analysis to ensure quality is incredibly important, and electrochemical biosensors can be used to meet those needs. As discussed in the previous section, glucose biosensors are the most common of all electrochemical biosensors and they have also been used to evaluate the glucose content of different foods and drinks. This idea has also been expanded to include other sugars, including lactose, maltose, galactose, fructose, lac-tulose, and trehalose. ... 

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