Orange juice, concentration

Just as frozen orange juice concentrate must be diluted before use by adding water, many chemical solutions must also be diluted. 

Figure 3. Changes in ascorbic acid content of freshly squeezed orange juice and reconstituted orange juice concentrate during storage in refrigerator (62)...

Gelation became a significant problem with the introduction of frozen orange juice concentrate, which initially was often packed without pasteurization. This product, when not frozen, rapidly developed low ester pectins by virtue of the PE it contained. Much of the research generated in response to this problem has been reviewed by Joslyn and Pilnik (22). Briefly, it has been found that gelation is the result of pectin deesterification (23), and increases as juice pulp (24), PE... 

The loss of ascorbic acid during extraction, finishing, and blending is minimal. Based on the data of Sale (70) and Hayes et al. (71), the loss should be no greater than 2%. Hayes et al. (71) prepared orange juice concentrates having 50-60% solids and reported a mean retention of 96.6% of ascorbic acid. 

Endogenous pectin esterases play an important role in citrus processing they have therefore been studied intensively. They cause cloud loss in citrus juices, which is due to the calcium precipitation of enzymatically de-esterified pectin. This is desirable in the production of lemon and lime juices but undesirable in the production of orange juice. In orange juice concentrates strong calcium pectate gels may form which cannot be reconstituted... 

Add 1 tablespoon of raspberry jam or orange marmalade, 1 tablespoon of frozen red grape or orange juice concentrate, 1 teaspoon of vanilla extract, or 1 teaspoon of instant coffee (decaf at bedtime). Or add a pinch of cinnamon or nutmeg, or both. Also experiment with flavor concentrates, such as orange, lemon, or rum extract. 

Crandall, P. G., Chen, C. S., and Carter, R. D. 1982. Models for predicting viscosity of orange juice concentrate. Food Technol. 36(5) 245-252. 

Alves, V.D. and CoeUioso, I.M. Orange juice concentration by osmotic evaporation and membrane distillation A comparative study, J. Food Eng., 74(1), 125, 2006. 

Ingredients (in descending order) Orange juice concentrate, water, acid citric acid E 330, vitamin C, natural flavours, stabiliser locust bean gum E 410, preservative sodium benzoate E 21, colour beta-carotene E 160a ... 

The effect of dilution of fourfold orange juice concentrate on the reflectance spectra obtained on 4 cm thick samples in thin walled polystyrene bottles is shown in Fig. 3.7. As can be seen, 4 cm is practically equivalent to infinite thickness. Kubelka-Munk absorption and scatter coefficients were calcrrlated from 2 rmn thick samples on black and white backgrotmds. On dilution, S... 

Orange juice concentrate, 42 Brix Orange juice, unconcentrated Grapefruit juice concentrate, 42 Brix Cantaloupes In syrup... 

Pasteurization appears to have a major impact on the stability of juice cloud in orange juice concentrates because of the deactivation of pectinesterase enzymes (Chandler and Robertson, 1983). 

FIGURE 11.14 Influence of water activity on HMF accumulation and brown pigment formation in orange juice concentrate at 45°C for 48 days. 

Spectral matching algorithms are also employed using multidimensional mathematics. Such techniques are often used in quality assurance programs where a spectrum of a known material is compared with incoming raw materials to check its purity or authenticity. For example, samples of orange juice concentrate were collected to represent the types available from two countries. In addition, samples that were known to be adulterated were obtained from one of the countries. All other samples were... 

Alves M.D., Coelhoso I.M. (2006), Orange juice concentration by osmotic evaporation and membrane distillation a comparative study, J. Food Eng., 57,153-163. Baker R.W. (2004), Membrane technology and applications, 2nd ed. (R.W. Baker, Ed.), John Wiley Sons, Chichester, West Sussex, England. 

Evaporation and Bypass in Orange Juice Concentration. In a process for con-... 

Liquid-solid suspensions, viscous aqueous and organic solutions, and numerous food products, such as margarine and orange juice concentrate, are often cooled or heated in a scraped-surface exchanger. This consists of a double-pipe heat exchanger with a jacketed... 

---