Testing Tomato-Product Quality in Considerably less than 30 Minutes

Although there is still considerable debate about whether the humble British chip is best accompanied by tomato sauce or mayonnaise, there is no doubt at all that tomato paste is the making of a pizza. Get that wrong and no amount of additional topping is going to rescue this great Neapolitan classic.

Contamination-free manufacture and packaging of tomato-related products is therefore of crucial importance, not just to lazy students, but also to the food industry.

Both lactate and ethanol concentrations can be used to help quantify the microbial load in these products as well as in the initial ingredients and all stages in-between, because ethanol-producing yeasts and lactate-producing bacteria are important contributors to the total microbial load. Obviously, the quicker any measurement of ethanol and lactate can be made the better, which is where the YSI Biochemistry Analyzer comes in. 

The YSI Biochemistry Analyzer, when configured with the YSI 2329 lactate oxidase membrane and a YSI 2786 alcohol oxidase membrane, can simultaneously measure lactate and ethanol after aspiration of just 15 microlitres of sample. What is more, thanks to YSI’s proprietary immobilised enzyme electrode technology, turn around time is less than two minutes.

To test the feasibility of this approach for tomato-containing products, diluted ketchup samples were obtained and spiked with lactate and ethanol to levels that would be typical of changes seen in microbial load tests. As lactate levels as low as 50ppm (mg/L) can indicate potential spoilage/flavour problems and ethanol levels in the 50-150 ppm are suggestive of yeast or mould effects, the tests were designed with this in mind.

Results showed that ketchup sample measurements were virtually unaffected by colour, density, pH, turbidity or the presence of other chemical substances. Therefore the YSI Biochemistry Analyzer can simultaneously measure both lactate and ethanol in a tomato matrix with the precision and accuracy required to make process and quality assurance decisions in tomato product manufacture.

Pizza lovers everywhere can rest easier knowing that there is now an even better way to ensure the quality of their favourite pie.

To download the application note please click on the PDF link above right.

Date added: 2015-08-18 12:55:36