Background/Aims: Green juices are promoted as a rich source of nutrients and vitamins. Unfortunately green juices are commonly made from green leafy vegetables that can contain high levels of oxalates. Several cases of acute oxalate nephropathy have been attributed to the consumption of green juices.
Methods: Two green juices were prepared, one using 20% spinach and another otherwise identically proportioned juice contained 40% spinach. Both the low and high spinach containing green juices were prepared using a masticating juicer (MJ) which produced a clearer thinner juice and a high speed blender (HSB), produced a thicker juice. Total, soluble and insoluble oxalate contents of the four juices were determined by HPLC.
Results: Overall there was no significant difference between the soluble oxalate content in the low spinach recipe (77.7 and 97.7 mg/100 g FW, HSB and MJ respectively). However the high spinach juice produced by the MJ had a significantly higher amount of soluble oxalate (364.1 mg/100 FW) compared to the HSB blender (275.3 mg/100 g FW).The ratio of soluble to total oxalate in the different types of juices was similar, for the low spinach juice 45 and 46% and 66 and 74% for the high, HSB and MJ, respectively.The consumption of 200 mL of any of the juices would lead to the consumption of between 155 - 728 mg of soluble oxalate.
Conclusions: Different recipes and different types of juicers give very different oxalate contents in the resulting juices.Funding Source: Lincoln University Post Graduate Research Fund