As part of the study, it commissioned the IFSH to investigate if fresh coconut water with pH above 4.6 can support the growth and toxin production of non-proteolytic and proteolytic strains of C. botulinum at 4°C and 10°C.
Potential for spores to germinate & grow
Dr. Errol Raghubeer, senior VP, Microbiology & Technology, Avure, told BeverageDaily this study investigated the potential for spores to germinate, grow and produce toxin by proteolytic and non-proteolytic C. botulinum in both filtered and unfiltered fresh coconut water treated with HPP (high pressure processing) and stored for 45 days.
The results found that although there was an increase in the total anaerobic count during the 45 days of storage, none of the samples showed toxin production.
“While we agree there is the potential for C. botulinum contamination in coconut water, this comprehensive study proves to us that HPP, combined with potential natural elements found in coconut water, is an effective food safety measure,” said Raghubeer.
“It is likely that naturally-occurring inhibitory compound or compounds in coconut water, make C. botulinum unable to germinate, grow or produce toxin, or that coconut water lacks certain key ingredients to promote growth and toxin production of C. botulinum.
“HPP of coconut water is a viable process for the inactivation of other vegetative pathogens of concern such as L. monocytogenes, Salmonella and E. coli.”
Harmless Harvest, Thailand
Avure conducted the study in response to concerns in the coconut water industry about C. botulinum because it was believed the low acid content of coconut water might lend itself to toxin production.
The US FDA issued a warning letter to Harmless Harvest with these concerns in November last year.
In a letter to Guy Gavelle, managing director, Harmless Harvest, Thailand, the FDA said the firm had advised the Agency its coconut juice products are intended to be further processed in the US via HPP.
“Your firm included with your HACCP manual for your microfiltration process a HACCP plan for the HPP intended to be applied by a US processor,” it said.
“However, the HACCP plan for the HPP processor does not identify the reasonably likely food hazard of toxin produced by Clostridium botulinum, to comply with 21 CFR 120.8(b)(1).
“Furthermore, the HACCP plan does not include control measures to produce a 5-log reduction in Clostridium botulinum, as required by 21 CFR 120.24, or the validation of the HACCP plan required by 21 CFR 120.8(b)(6).
“The study you submitted conducted by the University of Guelph entitled “High Hydrostatic Pressure Inactivation of Model Pathogens and Spoilage Microbes Introduced into Coconut Water” did not take into consideration the pertinent microorganism, Clostridium botulinum.
Clostridium botulinum toxin can cause death
“As a result of several instances of botulism poisoning from refrigerated carrot juice (a low acid juice), the Agency recommends a process be applied to low-acid juices that will ensure Clostridium botulinum growth and toxin production will not occur should the juice, as offered for sale by the processor, be kept unrefrigerated in distribution or by the consumer.”
The letter added spores of C. botulinum have demonstrated the ability to germinate and grow in low acid juices (such as coconut juice), producing toxin. Since C. botulinum toxin can cause serious illness, including death, in humans, the FDA requires this hazard is controlled in juice products.
Avure’s HPP equipment and services include manufacturing, engineering, procurement, parts and customer services in Middletown, Ohio, US; Global Headquarters and Customer Center in Erlanger, Kentucky, US; a parts distribution center near Amsterdam, Netherlands; and a global network of Avure Certified HPP Laboratories and independently operated Tollers and Service Providers.
“With proper temperature control, HPP remains the preferred method for treating coconut water to ensure food safety while maintaining the best flavor and keeping nutrients intact,” added Raghubeer.