The Original Juice Company, established in Melbourne in 1988, specialises in producing fresh fruit juices and new age beverages (pure drinking waters and electrolyte sports drinks). Turnover has grown from $800,000 in 1988/89 to $39 million in 1995. Its new manufacturing facility in the outer northern suburbs of Melbourne has the capacity to process over 90,000 tonnes of fresh citrus fruit per year. The company has recently expanded production to include long life products for the international market.
The process involves delivery of fresh citrus fruit which is stored in a cool room prior to processing. The fruit is chilled to 4 degrees Celsius and then washed and sorted prior to juicing. The juice is then chilled and stored in stainless steel tanks prior to packaging in containers ranging from 110 mL to 5 litres.
The peel waste from the juicing process is recovered in dry form as a high protein stock feed. To achieve the required degree of dryness the peel requires pressing. The liquid pressings, which averages 4,000 kilolitres per month, were historically discharged to sewer after on-site treatment. This effluent contains high levels of citrus oil and sugars, which contributed significantly to the waste loading of the effluent, particularly biochemical oxygen demand (BOD).
Cleaner Production Initiative
The cleaner production initiative that Original Juice has implemented is based around recovery of the citrus oil and sugars from the liquid pressings.
Citrus oil from the pressings is now being recovered in a vacuum distillation process. This technology was chosen instead of the traditional method of using centrifuges and polishers to recover the oil from a water/oil emulsion, because it maintains high yield levels at high production levels. The conventional water/oil emulsion method can achieve yields of 3.5 to 4 litres of oil per tonne of citrus fruit processed at low production rates, but this falls to approximately 1.5 litres per tonne at higher production rates, due to reduced residence times. The vacuum distillation consistently achieves 4 litres per tonne at high production rates, with an effective yield consistently above 60 per cent. The use of vacuum distillation does incur additional energy costs, and the company had to install a gas fired boiler to generate steam for both the distillation and evaporation processes.