The New South Wales Department of Primary Industries has released a best practice guide for rockmelon and specialty melon growers. The purpose of the guide is to help producers grow melons safely and prevent food-borne pathogens, particularly Listeria, from contaminating the produce.
Rockmelons have been linked to some serious food-borne illness outbreaks, including an outbreak of Listeria in 2018 which was linked to a NSW rockmelon farm. Outbreaks such as these not only make people sick, they also cause significant financial loss and a loss of confidence in the Australian rockmelon industry.
The industry has taken a huge hit in the past few years, with domestic and export sales ceasing for around six weeks during the 2018 outbreak. Two years later, the industry has only now regained its market share.
It is evident that food-borne illness outbreaks can have devastating effects on those who fall ill, and the food industry as a whole. In order to prevent food-borne illness outbreaks, rockmelon growers should follow food safety best practices.
Best practices for growing melons
Preharvest safety
Soil
Rockmelons grow close to the ground, and as such, they have a greater likelihood of having their surface contaminated by pathogens found in soil (e.g. Listeria and Salmonella). Rockmelons also develop what are called ‘ground spots’ on the rind. These ground spots are areas of the rind which are thinner and less developed due to contact with the ground. Ground spots are more susceptible to bacterial growth and are an area of the rind where microbes can be internalised when the rockmelon is washed after being harvested. It is advised to use plastic mulch in order to reduce the transfer of pathogens to ground spots.
Water
The water that is used to grow rockmelons is extremely important. This is because the quality of the water poses risks if it is contaminated chemically or with pathogens that can then be transferred onto the rockmelons. Growers must ensure that the water is of high quality by maintaining regular monitoring and testing.
Location
Growers are encouraged to pick the site to grow the rockmelons extremely carefully. Sites for growing rockmelons should always be assessed for any type of physical contaminants, including microbial and chemical contaminants. Knowing that these hazards are there within the soil gives growers the opportunity to choose another location or remove the contaminants if possible.
Dust storms
Many areas that rockmelons are grown are subject to dust storms. Dust storms are a concern as they increase the exposure of rockmelon crops to contaminated soil through the wind. It is also a concern as rockmelons do not do well against dust storms and therefore they must be protected. Windbreakers and barriers should be used to protect crops from dust storms and reduce their exposure to contaminated, wind-blown soil.
Harvesting Safety
Harvesting the rockmelons is a significant point in the production process. This is a point where contamination can easily occur due to the rockmelons being handled and moved. Here are some key best practices to follow while harvesting:
- move harvested melons immediately to the packhouse for pre-cooling, washing and sanitising
- train employees to identify food safety risks in the field and report them
- avoid mechanical damage to the fruit during harvesting
- do not throw the rockmelons which can cause damage
- cull diseased, overripe and damaged rockmelons to prevent the good melons from being contaminated
- regularly clean and sanitise harvesting equipment
- do not walk on conveyor belts which can cause cross-contamination of shoes
- do not use harvesting equipment to transport garbage
Postharvest Safety
Cold storage
Keeping rockmelons at an appropriate temperature helps with keeping the quality of the product as well as keeping food contamination at bay. Rockmelons can be stored for up to 21 days at 5 °C. The cold storage rooms that rockmelons are stored in should be clean — they must be regularly cleaned and sanitised as part of the Cleaning & Sanitising schedule. Drip pans can be sources of microbial growth and must be properly cleaned and sanitised as well.
Other key considerations for cold room storage include ensuring that there is no cross-contamination of the rockmelons from other products in the cold storage. It is also essential to maintain and monitor cold storage temperatures as fluctuating temperatures can cause pathogen growth on rockmelons.
Cleaning and sanitising
Cleaning and sanitising the rockmelon storage areas is essential to minimising contamination. Hotspots for cross-contamination should be identified in storage areas and these areas should be cleaned and sanitised more frequently.
It is also important to know what are the appropriate detergents and sanitisers that can be used in the food processing environment. Detergents and sanitisers that are used must be approved for use on food contact surfaces and meet all legal requirements. All of the manufacturer’s instructions should be followed, including product concentrations.
Food Handler safety
Personal hygiene
Inadequate food handling by food workers is a significant source of food contamination. All staff, including contractors and visitors must practice impeccable personal hygiene in order to reduce the risk of contaminating rockmelon crops. Contamination can occur from hands, other parts of the body and clothes. This is why it is essential that all staff wash their hands using the proper hand washing method.
Staff must wash their hands before beginning work. They must wash their hands after:
- visiting the restroom
- blowing their nose
- sneezing or coughing
- touching their face
- eating or smoking
- touching animals
- handling waste
- handling cleaning materials/chemicals
This is not an exhaustive list of all the times that staff should wash their hands. Organisations must ensure that staff are trained to wash their hands based on the requirements and day-to-day operations of the establishment.
Illnesses
Staff must not come to work if they are feeling sick. Staff must be trained on how to inform management that they are sick and cannot come into work. Staff must also be trained on how to report an illness (theirs or another person’s) while working at the premises. It is absolutely essential that ill staff are not working within the establishment as this can cause contamination of the rockmelons through biological contamination.
Food safety practices are essential
The best practices listed above are not an exhaustive list of everything rockmelon growers need to do to ensure the safety of their product. Growers should consult the NSW Department of Primary Industries Melon Safety Guide for more information on what is required to maintain food safety.
Organisations must also ensure that all Food Handlers have their Food Handler Certification. Not only is this a best practice, but it is a legal requirement for anyone who works with food in Australia.
The Australian Institute of Food Safety is a nationally recognised provider of food safety training through the Food Handler Certification course.
