Adulteration of fruit juices

Wrolstad, R.E., Hong, V., Boyles, M.J. and Durst, R.W. 1994. Use of anthocyanin pigment analyses for detecting adulteration in fruit juices. In Methods to Detect Adulteration of Fruit Juice Beverages (S. Nagy and R.L. Wade, eds.) pp. 260-286. AgScience, Aubumdale, Fla. 

Nagy, S. and Wade, R.L. (eds.) 1995. Methods to Detect Adulteration of Fruit Juice Beverages, Vol. I. AgScience, Aubumdale, Fla. 

A Versari, S Biesenbruch, D Barbanti, PJ Famell. Adulteration of fruit juices dihydrochalcones as quality markers for apple juice identification. Lebensm Wiss Technol 30 585 -589, 1997. 

Adulteration of Fruit Juice Beverages, edited by Steven Nagy, John A. Attaway, and Martha E. Rhodes... 

The adulteration of fruit juices is widespread. As with any commodity, juice manufacturers, blenders and users can secure considerable financial benefit from adulterating fruit juice. It should be emphasised that food safety issues are not normally an issue in fruit juice adulteration. The issue is simply the fact that traders and consumers are being defrauded an adulterated fruit juice sold as pure fruit juice is not as it has been labelled. 

Fructose syrup. In addition to the glucose/fructose syrups mentioned above, a fructose syrup has been produced using inulin as a source. Inulin is the fructose analogue of starch, and the chicory root is the standard source for commercial hydrolysis. Fructose syrups are usually too expensive for routine use in beverage production but they have been employed where a particular claim is to be made for fructose. They have also been used for the adulteration of fruit juices as they are chemically difficult to detect. Detection is possible at the sub-molecular level by techniques such as stable isotope ratio measurement. Fructose is also manufactured using sucrose as a starting material. 

Over the past 30 years, extensive research has been carried out to find ways to detect the adulteration of fruit juices. The approaches have developed from simple procedures, such as measuring the potassium and nitrogen contents of juices, to the use of highly sophisticated and expensive equipment to detect the most recent approaches that unscrupulous suppliers may be using to extend their products. Such adulteration often involves the substitution of some of the fruit juice solids by sugars derived from beet, cane, com or inulin, or the addition of cheaper juices or second extracts of the fruit. 

Hammond, D.A. (1996) Methods to detect the adulteration of fruit juice and purees, in Food Authenticity (eds RR. Ashurst and M J. Dennis), Blackie Academic Professional, Chapman Hall, London. 

Many applications of SNIF-NMR to the determination of the origin and quality of non-alcoholic products have been demonstrated.17 These include studies of the origin (natural or synthetic) of aromas and flavours such as vanillin337 338 and anethole,339 of vinegars340 and of possible adulteration of fruit juices and jams. The technique is expected to assume increasing importance in response to the demands of consumers and regulatory authorities for guarantees of food quality. 

Adulteration of fruit juices and concentrates is a problem that has received wide publicity. Common methods of adulteration either alone or in combination include addition of water, corn syrup, cane and beet invert sugar, peel extract, pulp wash, cheaper... 

Stable isotope ratio analysis Adulteration of fruit juices or honey by addition of bulk sweeteners can be detected by stable isotope ratio mass spectrometric analyses, because the naturally occurring carbon isotope ratio of to in honey and fruit is different from that in corn or sugarcane although not from that in sugar beet. The oxygen isotope ratio may be used for beet sugar addition. 

Rouseff RL (1988) Differentiating citrus juices using fiavanone glycoside concentration profiles. In Nagy S, Attaway JA, Rhodes ME (eds) Adulteration of fruit juice beverages (Food science and technology, vol 30) Marcel Dekker, New York, pp 49-66 Rouseff RL (ed) (1990) Bitterness in foods and beverages. (Developments in Food Science, vol 18) Elsevier, New York... 

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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