There is a range of advice available for food businesses about COVID-19 for each state and territory coordinated by Food Standards Australia New Zealand at this link.
WHO interim advice COVID-19 and food businesses
Food businesses and COVID-19 NSW Food Authority
COVID-19 Information for food businesses SA Health
COVID-19 advice for food businesses Safefood Queensland
COVID-19 business advice WA Health
COVID-19 advice for food businesses Health.Vic