Juice with pulpwash, adulteration

In conclusion, it has been shown that the visible and ultraviolet absorption, and room temperature fluorescence spectra, obtained from alcoholic solutions of orange juice and related products, may be used for product characterization. The complementary absorption and fluorescence spectra may be utilized for the qualitative detection of adulteration of reconstituted frozen concentrated and single-strength orange juice with pulpwash. Previous investigations (chemical and elemental profile analyses)... 

Lifshitz et aK ( ) investigated the purity of Israeli citrus juice by a multivariate method. They selected 5 analytical parameters and concluded that adulteration or dilution of 15% or more was very likely to be detected at a 1% level of significance. However, adulteration with orange pulpwash was not included in their study. 

Visible and ultraviolet absorption and fluorescence spectra, obtained from alcoholic solutions of a commercially packed (out of the State of Florida) FCOJ, are presented in Fig. 9, 10, 11 and 12. Qualitatively, Fig. 9 reveals a lack of resolution in the visible absorption region and a well resolved peak at 280 nm. Comparison with Fig. 1 and 3 shows its absorption characteristics to be more similar to those of orange pulpwash in Fig. 3, indicating adulteration by pulpwash addition. Fluorescence excitation spectra (Fig. 10, 11) reveal well defined peaks at 270-75 nm, and Fig. 12 a shoulder at 270-75 nm. The spectra appear deformed when compared to Fig. 2 and 4 of pure orange juice. However, characteristics are similar to those obtained from pulpwash and very similar to those obtained from prepared model systems. Qualitatively both visible and ultraviolet absorption, and room temperature fluorescence indicate the presence of pulpwash in the FCOJ sample. The spectra are complementary. Absorption also did not indicate further adulteration by dilution which would have been denoted by weaker overall absorption and a shift at 227 nm to shorter wavelength. The sum of absorption at 443, 325 and 280 nm is 0.098 + 1.040 + 1.622 = 2.760 absorbance units. Florida State statute 20-64.07(l)(a) requires FCOJ to be 44.8° Brix which reconstituted to 12.8° Brix (16) and Federal standards, Section 52.2582(a), require 41.8° Brix, reconstituted to not less than 11.8° Brix (17). Therefore, the sum of absorbance is multiplied by the ratio of 12.8 to 11.8° Brix, with a corrected sum of 2.995. The sample absorbance ratio at 443/325 nm is 0.098/1.040 which is equal to 0.094. If the sum and natural log ratio values are substituted into the regression equation ... 

Phenolic compounds have sometimes been used to detect adulterations of fruit juices and jams. Most of them are flavonols, but some HCA derivatives can be used since they are typical of some fruit species such as tartaric derivatives in grape. For example, grape juice can be detected by the presence of caffeoyl-, / -coumaroyl-, and feruloyl-tartaric acids, whereas the presence of quinic esters of HCA would imply adulteration with other fruits. A method has also been developed for detection and quantitation of pulpwash, a lower-quality juice product, in orange juice [9] feruloyl and sinapoyl glucose, in addition to different other phenolic compounds, were present in much larger amounts in pulpwash. 

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