Stabilization of acai (Euterpe oleracea Mart.) juice by the microfiltration process

Acai berry, a Brazilian palm fruit widely distributed in northern South America, is acknowledged for its functional properties such as high antioxidant capacity and anti-inflammatory activities. Although the acai juice is highly appreciated in Brazil and even worldwide, its commercialization is still limited. Microfiltration process is largely applied in juice processing, eliminating many of the traditional processing steps and reducing time, energy and addition of clarifying agents. Furthermore, microfiltration process may eliminate microorganisms and compounds responsible for turbidity in the juice. Current assay applies a microfiltration process to obtain a stabilized acai permeate pulp. Microfiltrations of acai pulp were carried out in a dead end configuration with a flat membrane of 0.22 mu m pore size. Permeate pulp was characterized according to its turbidity, lipid concentration and microbiological analysis. Initial permeate flux was 103 kg m(-2) h(-1). After an initial flux decline during 30 min., due to membrane compaction and fouling occurrences, flux was stabilized at 20 kg m(-2) h(-1). The microfiltration process reduced the initial acai pulp turbidity by 99.98% and lipids were not identified in the permeate. Microbiological analysis showed that the contamination by microorganism decreased in the permeate pulp when compared to that in raw acai pulp.