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.

Orange juice was stored in glass bottles and polyethylene/barrier material laminated cartons at 4°C for 24 wk. Studies were carried out on the absorption of 19 orange juice aroma compounds (e.g ethyl butyrate, d-limonene) into low density polyethylene (LDPE). Sensory evaluations were performed on the same orange juice in different packages over the storage period. A reduction of d-limonene of up to 50% by absorption into the LDPE inside coating was observed. However, an experienced sensory panel did not distinguish between orange juice stored in glass bottles and polyethylene laminated cartons.

A batch of frozen concentrated grapefruit juice (GJ) was reconstituted to 10" Brix with water and adjusted with sucrose, citric acid and/or deacidified GJ to produce five experimental samples with Brix:acid ratios from 7-15. Consumers from four large U.S. cities evaluated the samples for flavor, preference and five other quality attributes. Flavor means varied within an acceptable range. Preference was for samples in the 8.4 to 11.1 ratio range. Nonusers preferred 11.1 ratio juice and rated the three lowest ratio juices lower than users. As ratio increased, consumer perception of sweetness increased and decreased for tartness, bitterness, and aroma. All samples were judged somewhat too tart and bitter (except at 15 ratio) and not quite sweet enough.

Six samples of each of 5 types of Florida-processed grapefruit juice obtained from the U.S. retail market during 1983 were evaluated for overall flavor and other quality attributes by 108-member consumer sensory panels. Grapefruit juice consumers found overall flavor acceptable and color about right, aroma and sweetness lacking (P < 0.01) and tartness and bitterness excessive (P < 0.01). Juices were measured for content of furfural, naringin, limonin, Brix and acid with Brix:acid ratio being calculated. Most factors varied according to type of product. Many correlation coefficients, although mostly low, were found significant between factors (P < 0.05). Panelists perceived bitterness to a measurable extent as tartness or lack of sweetness and did not clearly differentiate between these two sensory attributes.