Quantitative Testing, Spoilage Organisms

Microbial spoilage of food has been a constant nuisance and an unavoidable problem throughout history, an immense number of fungi and bacteria take the food as nutrient sources. Therefore, microbiological safety is necessary for quality control in the food industry. Loss through spoilage can be costly for producers, whether it affects ingredients and a finished product or not. Food security always is the focus of consumer attention. Quantitative testing can accurately determine the concentration, amount or percentage of one or more organisms in a test sample. Therefore, it is crucial to detect and quantify the spoilage organisms in food to keep it away from human consumption.

For example, beef adopts cryopreservation, however, can still be contaminated by some psychrophilic microorganisms at low temperature. What is worse, human eyes may not be sensitive enough to detect some of the contamination.

Spoilage in ground beef

Beer's ethanol concentration and low pH are not suitable for the growth of most bacteria. However, the loss of whole batches of beer can still be caused by bacterial contamination.

Spoilage in beer

We often use different methods to detect spoilage microorganisms in various types of food. Frequently used methods for removing (detaching) microbes from food product or swab samples include blending, stomaching (or macerating) and rinsing. After successfully detaching microbes from food, a rapid PCR test can be used for the quantification of microorganisms. Normal plate counts have also been used to quantify the bacterial number in different samples. Several other methods can be explored, including, but not limited to:

A competitive-type enzyme-linked immunosorbent assay (ELISA): application to total residue determinations for spectinomycin-related residues in food animal tissues.

VIS/NIR Spectral Imaging: Quantitative Analysis of Meat Spoilage, especially among the beef.

Microbiological analysis total viable count (TVC): Pseudomonas, Brochothrix thermosphacta, Lactic acid bacteria (LAB), Enterobacteriaceae, Yeast and molds.

Quantitative analysis: detect food spoilage using fresh sample of lipid containing food, measuring amount of noncycloxygenase produced prostaglandin derivatives.

MALDI-TOF-MS and Multivariate Analysis: Detection and Quantification of Bacterial Spoilage in Milk and Pork Meat ^[1].

MALDI-TOF-MS

A wide range of dehydrated and ready-to-use culture media: used for detection organisms which caused fruit juice spoilage, including lactic acid and acetic acid bacteria, yeasts and molds.

We offer spoilage quantifications for following bacteria, but not limited to

Spoilage Indicators

• Aerobic and Anaerobic plate counts

• Coliforms

• E. coli

• Enterococcus

• Yeast & mold counts

• Acidophiles

• Anaerobes

• Spore counts

• Psychrotrophs

• Gram Positive Bacteria

Gram-positive bacteria are generally considered as the most threatening contaminants in the brewery because of their rapid growth rate and tolerance to high temperatures and low pH conditions.

Gram Negative Bacteria

Important Gram-negative contaminants in the context of beer brewing are acetic acid bacteria, Zymomonas spp., Pectinatus spp., and various Enterobacteriaceae. These bacteria distort the fermentation process and produce undesired by-products. They survive in the fermentation process and can transfer into the finished product.

The above-mentioned are some of the basic detection methods for spoilage microorganisms in our company. Alfa Chemistry is professional in spoilage organisms quantitative testing and we can provide accurate and reliable test results within the time constraint. We have conducted food safety studies in many aspects. Please feel free to contact us if you have any concern or requirements to perform any food testing. Check our instruments list for our expertise.

Reference

• Nicolaou N, Xu Y, Goodacre R. Detection and Quantification of Bacterial Spoilage in Milk and Pork Meat Using MALDI-TOF-MS and Multivariate Analysis [J]. Analytical Chemistry, 2012, 84(14):5951-8.