R&D Roundup (cont) Ben Brown - Industry Development Manager
Risk Reduction Steps The control of Salmonella and aflatoxin contamination must be practised across the entire supply chain as a crucial part of any HACCP or QA program. Pasteurisation may form part of this program as it is effective in managing Salmonella however it is not effective in removing aflatoxins and consequently other risk reduction steps need to occur. In anticipation of the results from the current food safety R&D project, I would encourage you to refer to the table below and the ABA Fact Sheet 10 – What Threatens The Safety Of Almonds. by Prue McMichael of Scholefield Robinson Horticultural Services. For further information contact: Ben Brown Industry Development Manager Almond Board of Australia P 08 8582 2055 or 0447 447 223 E: email@example.com
Fungal and Mycotoxin Contaminants – Aspergillus and Aflatoxins Aflatoxins are derived from fungi, primarily Aspergillus flavus and Aspergillus parasiticus . The growth of the fungi inside almond hulls and shells is affected by temperature, humidity and moisture levels. In mild- warm temperatures (15-37 +° C), spores of Aspergillus spp. can germinate and produce heat stable aflatoxins within 24-48 hours of nut exposure to a moist environment ( ≥ 7% kernel moisture). Once inside the shell, the nutrients of the kernel provide a rich growth environment. Affected nuts are not always ‘mouldy’ but kernels that display yellow-green growth may be contaminated. However, not all moulds are Aspergillus spp. To address the risk of mycotoxins the Australian almond industry has recently invested in a R&D project with Horticulture Australia Limited (HAL), Department of Primary Industries (DPI) and
other microbial contaminants, I would like to take this opportunity to briefly describe two key contaminants facing our industry; Salmonella and aflatoxin. Bacterial Contaminant - Salmonella Salmonella is the leading cause of food- borne illness in many countries. In the last 10 years in Australia there have been 229 recalls of food products caused by microbial contamination with Salmonella being the second most common (FSANZ food recall statistics, 2002 to 2011). The primary habitats of Salmonella spp. are the intestines of birds, animals, some insects, reptiles and mammals, and consequently are frequently located in the environment. Salmonella spp. grow over a wide temperature range (5-45°C) at moisture levels above 10% and are therefore very persistent in the environment. Even at lower moisture levels these bacteria remain a problem because their tolerance to high temperatures is increased at low moisture levels. Salmonella spp. rapidly proliferate in wet almond hulls and free moisture allows bacteria sitting in soil on hulls to move onto shells, through the shell and onto the kernel. If established inside a shell, the bacteria are protected from drying conditions and direct sunlight, and they can rapidly multiply. The persistence of Salmonella spp. at a wide range of temperatures and at low moisture makes them an ongoing concern in almond production, handling, storage and processing or wherever soil or dust is present. It is thought the Salmonella contamination in 2001 and 2004 in California and to some extent in 2011 and 2012 in Australia is linked to a micro climate created with the assistance of large rainfall events prior or during harvest. The combination of rainfall with moist soil, premature fruit drop, shaken fruit on the ground, fruit missed during harvest, and a nutrient rich and moist hull, exposed the product to a prolonged drying process both during harvest and in storage.
CSIRO. Research is only in its second season but preliminary findings indicate: • Aspergillus growth can begin on split fruit in the tree prior to harvest, but is largely been found in covered stockpiles.
• The longer the fruit is
held in a stockpile the greater the opportunity for Aspergillus growth to occur.
• Aspergillus growth is mostly located at the
surface and top of covered stockpiles,
particularly in areas in contact with the tarp. • Carob moth damage can be associated with Aspergillus growth but is not an exclusive relationship. • Appropriate stockpile
management is crucial for minimising aflatoxin contamination risks.
Appropriate stockpile management is crucial for minimising aflatoxin contamination risks.
References FSANZ. Food recall statistics between 1 Jan 2002 – 31 Dec 2011.
Gouk, C. 2013. Research update: HAL Project 11009, Food Safety in Almonds Stage 2. Unpublished. McMichael, P. 2010. Fact Sheet: What Threatens the Safety of Almonds? Almond Board of Australia.