FCOJ

Fig. 4.22 Apparent specific surface A(app) of carbons obtained from the decomposition of polymers, plotted against the carbonization temperature, (a) Polyfurfuryl carbons (b) dibenzanthrone carbons (c) polyvinylchloride carbons. O, A(app) estimated from CO2 isotherm at 195 K (a fCOj) = 17-0 A ) A. /f(app) estimated from N2 isotherm at 77 K = 16-2 A ). (Courtesy Marsh and Wynne Jones.)...

LEVELS OF CAROTENOIDS (MG/LITRE) IN AUTHENTIC (HAND-SQUEEZED ORANGE JUICE, FROZEN CONCENTRATED ORANGE JUICE (FCOJ) AND IN FROZEN CONCENTRATED ORANGE PULP WASH (FCOPW), BOTH DILUTED TO 12° BRIX. (N = 5 FOR PERA RIO, N = 4 FOR NATAL, N = 3 FOR VALENCIA AND HAMLIN VARIETIES, AND N = 2 FOR FCOPW)... 

For example, frozen concentrated orange juice (FCOJ) - the industry standard material for orange - is haded as 65-66°Brix concentration. Oranges that are used may, on pressing, yield a juice of variable Brix - say, from around 10° to as much as 14 or 15°. Thus, the degree of concentration required to produce 65-66°Brix concentrate will be slightly different for a 10°Brix juice compared with a 13°Brix juice. 

The use of citrus fruit, especially oranges, dramatically increased in the U.S. after World War II (1 ) because of the introduction of frozen concentrated orange juice (FCOJ) to the market. Citrus fruits, being subtropical products, did not enjoy the popularity of other fruits, e.g. apples, because the locality of production were usually not near the world population centers and because of perishability of citrus fruits during storage. 

The inverse relationship between limonin content and taste preference was confirmed in another study (41) using a stepwise multiple regression analysis of data from 60 samples of commercial frozen-concentrated orange juice (FCOJ) packed during two seasons. This and a latter report (42) concluded that limonin content was highly correlated with the flavor quality of the juice. 

There is much that can be said in favor of the consumption of fresh fruits and vegetables in the daily diet. In much of the world, citrus is consumed primarily as the fresh fruit, but in the United States processed products are consumed as the major source of citrus in the diet. The main staple of processed citrus juices in the U.S. is frozen concentrated orange juice (FCOJ). 

Other mineral elements are present in citrus juices in measurable quantities. McHard et al. (34) reported on the trace element contents of Florida and Brazilian orange juice. They cited concentration ranges for 25 elements. Ting (23) reported that calcium, iron, phosphorus, magnesium, zinc, and copper are present in reconstituted FCOJ at levels equivalent to about 1% to 5% of their respective U.S. RDA s. 

According tc Ting (23,41), a serving (177ml) of reconstituted FCOJ delivers about 19g of carbohydrate and 84 calories contributed primarily by the sugars, sucrose, glucose, and fructose. 

Adams (24), indicates that a serving of reconstituted FCOJ delivers 92 calories, whereas grapefruit and tangerine, juice deliver 76 and 68 calories per 177ml, respectively. 

Frozen concentrated orange juice (FCOJ) is by far the most widely distributed of the processed citrus products. First marketed in the mid-1940 s, it has grown in consumer acceptance until the present day, and to the point where its volume consumption exceeds the combined total for all other processed citrus products. 

FCOJ and other frozen concentrated citrus juices are produced by the process outlined in Figure 4. Prior to evaporation the process includes extraction, finishing, and blending. In the evaporator, the juice may be concentrated to 45°Brix (% soluble solids) or higher and, as a matter of routine practice, most of the evaporator pumpout (concentrate) is at 65-68°Brix. 

The concentrate can go to low-temperature stcrage or directly to processing for FCOJ. During the fruit processing season, cutback juice may be used to dilute the concentrate to 45°Brix. At other times, essence and water are used to prepare FCOJ. Berry and Veldhuis (3) reviewed this process in great detail. 

Average Nutrient Delivery per Serving of Reconstituted FCOJ (12.8°Brix) in Relation to U.S. RDA... 

Bissett and Berry (76) reported on the ascorbic acid retention in orange juice as a function of container type. They stored FCOJ in fcil-lined cardboard, rectangular cartons and in polyethylene (PE)-lined fiber cylindrical cans for a year at -20.5°, -6.7°, and 1.1°C. At -20.5°C, the ascorbic acid retention was 93.5% in the foil-lined cartons and 91.5% in the PE-lined cans. Neither container proved effective above freezing due to microbial spoilage. The foil-lined carton was superior at 1.1°C, in that 89% of the ascorbic acid was retained after three months. In the PE-lined can, the retention was 44% after three months at 1.1°C. 

Other nutrients were measured in acid-reduced orange juice and, for the most part, no significant changes were observed from what would be expected for freshly extracted juice or reconstituted FCOJ. Some data relative to the other nutrients are presented in Tables IX and X. 

Based on a review of all the data gathered for reduced-acid FCOJ, it is apparent that any changes that do occur are of an insignificant nature and do not alter the nutritional quality of the processed orange juice. The product of commerce is of equivalent quality to the more popular product, frozen concentrated orange juice. 

The market for chilled citrus juices is one of the fastest growing segments of the domestic retail market, and now is second only to FCOJ in terms of volume consumption. Since its inception in the mid-fifties, this category for processed citrus juices has... 

Ting, S.V. "A Brief Report on Nutrition Labeling of FCOJ" ... 

In order to monitor the flavor of their products more closely, the Florida Citrus Processors Association has contracted with the USDA Processed Products Branch to operate a taste panel in which current FCOJ production is tested on a weekly basis. The panel consists of local consumers (generally housewives) and personnel from each of the participating plants (other types of citrus products have been evaluated in the past). Panelists rate samples on a 9-point scale from a low of "extremely poor" to a high of "excellent". Juices are ranked according to flavor score and a copy of the rankings are sent to each processor with only that particular processor s product identified (3). 

In the United States and other countries, companies (primarily dairies) that reconstitute frozen concentrate for manufacture into single-strength products or manufacture FCOJ from bulk concentrate are also interested in monitoring flavor quality of their products. 

FCOJ. Proper reconstitution of FCOJ is essential for valid taste panel results. Since orange juice flavor is of a rather delicate, mild, or light type, the water source used to reconstitute the concentrate must be relatively free of off-flavors, such as sulfurous. Distilled water should be used whenever practical. In addition, if the water used for reconstitution is placed in a refrigerator, walk-in cooler, etc. for chilling, care must be taken to have the water container covered securely to eliminate possible absorption of foreign flavors. And, of course, the reconstituted product itself, if being chilled prior to tasting, should be protected. 

There are several methods available for reconstituting FCOJ so that the final desired dilution is correct. Reconstitution of concentrate requires use of a precise scale or balance, sugar... 

Of course, identical reconstitution methodology could be applied to frozen concentrated grapefruit or other citrus juices as well as for FCOJ as discussed above. 

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