Shelf life and quality of freshly squeezed, unpasteurized, polyethylene-bottled citrus juice

Florida's chief orange and grapefruit cultivars were used to produce five freshly squeezed, unpasteurized, polyethylene-bottled juices using commercial conditions. Juices were stored at different temperatures. Shelf life depended primarily on storage temperature: -1.7 degrees C, 20-23 days; 1.1 degrees C, 16-22 days; 4.4 degrees C, 10-16 days; and 7.8 degrees C, 5-8 days. Staleness was the primary off-flavor limiting shelf life at the three lower temperatures while spoilage with diacetyl was primarily responsible at 7.8 degrees C. At the three lower temperatures, microbial counts generally decreased markedly during storage, while at 7.8 degrees C, an increase was generally noted. Ascorbic acid retention after 2 wk of storage at the three lowest storage temperatures was about 91-93% for two orange juices and 86-88% for the grapefruit juice