"Fruit Juice and Nectar – Lots of Fruit and Nothing Else?"
23.04.2013 Fruit Juice and Nectar – Lots of Fruit and Noth- ing Else? Report from a day in the lab CVUA Stuttgart focused on analyzing fruit juices and fruit nectars in 2012. From a total of 471 samples, 90 juices and nectars from various fruits were given a more detailed analysis of additives (preservatives, food dyes, sweeteners, and sulfur dioxide) and residues of heavy metals and calefaction products. In addition, spoilage parameters such as alcohol and lactic acid were also investigated. The results are gratifying: neither banned additives nor excessive amounts of undesirable residues were detected. And other than minimal traces, these products are really alcohol-free. Fruit juice and nectar – liquid fruits without additives? While the consumer often finds a long list of ingredients on soft drinks, with as many as 10 or more individual ingredients complete with additives, a look at the contents in fruit juice requires only a glance. In general, juic- es are made with only one ingredient: fruit (see Info Box). Fruit juice – „fluid“ fruits ADDRESS Schaflandstraße 3/2 70736 Fellbach EMAIL Poststelle@cvuas.bwl.de PHONE +49 711 3426 - 1234 INTERNET www.cvuas.de FAX +49 711 588176 Seite 2 von 5 Info Box Juice, Nectar, Soft Drinks – Differences in Fruit Content Fruit juice is made by pressing the juice out of fruits; the juice contains, there- fore, 100% fruit. Fruit nectar has, depending on the type of fruit, a minimum fruit content of 25 i % (currant nectar), up to 50 % (apple nectar). Water and sugar are added. Fruit drinks have, depending on the type of fruit, a minimum fruit content of 6% (orange drinks) up to 30% (apple drinks). Water and sugar are added, and flavoring agents may be added as well. Fruit spritzers are made with fruit juice and carbonated water. The fruit content is that of the fruit nectar. Soft drinks and other refreshment drinks normally contain fruit in amounts of 3% to a maximum of 15%. Other ingredients, in addition to water and sugar (or artificial sweeteners), include citric acid, flavoring agents, food dyes, preserva- tives and possibly caffeine and carbon dioxide. Legal requirements concern fruit juice and fruit nectar products with high fruit content for which additives, with few exceptions, are neither neces- sary nor permitted. It is the task of food inspectors to monitor adherence to this regulation; CVUA analyzed 90 fruit juices and nectars in 2012 with an especially critical eye. Preservatives such as, for example, sorbic acid or benzoic acid are not permitted in these drinks. Possible spoilage due to bacteria, yeast and mold are prevented by procedures such as preservation via heat or sterili- zation filtration. The results of our analyses were encouraging: in 89 of the 90 juices and nectars tested there were no preservatives detected. And the one excep- tion? A sample of cranberry nectar. This fruit contains benzoic acid natu- rally, but the amount of 37.2 mg/L found in the drink had no preservative effect. Sulfur dioxide also acts as a preservative, but more than that it is effective against oxidation processes which, among other things, lead to the „browning” of foods. When properly labeled, sulfur dioxide is permitted in, for example, wine, dried fruits, or marmelade, but not in fruit juice or fruit nectar. From a health perspective, this is fortunate because sulfur dioxide has the potential to cause allergies, which is problematic since juices and nectars are also drunk in large quantities by children. None of the 61 ana- lyzed samples were detected with sulfur dioxide. „Sugar sweet“ or „artificially sweet“ drinks? Analyses revealed differences in artificial sweeteners, such as sodium cyclamate, Saccharin, Aspartame, Acesulfam, etc. These are often found Seite 3 von 5 in soft drinks (labeling is required). For fruit juices, however, the sweet- ness should come from the fruit itself. All the manufacturers of the 39 analyzed juices were in line with this guideline. This is different with fruit nectars, where it is permitted to add artificial sweeteners in lieu of sugar, either partially or completely. In this case the consumer is informed via the indication „with artificial sweetener“, which must be near the food label. One of the 12 analyzed nectars, a “multi-vitamin nectar” contained Sac- charin and sodium cyclamate, which was correctly labeled. Fruit juice and nectar should be colorful; depending on the type of fruit, dark red, orange, or blue, thanks to the naturally occurring colors of the fruit. The intensity of the color is not permanent, however. The effects of light, oxidation and long storage time cause the colors to pale. A few drops of artificial food coloring, which is permitted in confectionaries and soft- drinks, could help make the product more visually attractive, but is not allowed. Our investigations revealed no artificial food coloring. The colors were “real“ - a result of the fruit alone. Contaminants in healthy drinks – not wanted Following the positive report „Manufacturers resist unpermitted additives“, the question is raised regarding other substances that may have landed in drinks inadvertently, so-called contaminants. Residues of metals, including heavy metals, are found in many foods in the slightest of concentrations. Law makers have, therefore, established maximum limits for select foods. For fruit juices and nectars a maximum level exists only for lead: 0.05 mg/L. In 88 of the 90 analyzed juices and nectars the quantity of lead was under 0.02 mg/L, less than half of the permitted concentration. Only two samples contained more; they were nevertheless under the maximum limit. Metals for which there are no maximum limits established (cadmium, iron, nickel, chromium, arsenic, quicksilver, thallium and copper) were detected in the juices and nectars. Fortunately, the values were under the limit of determination or existed in quantities that are not a health risk, even when consumed in large amounts by children. Old storage tanks for high quality drinks? A special case among contamination from metals is that of aluminum. When aluminum is found in fruit juices or nectars in relevant concentra- tions, it comes from aluminum tanks, although this is seldom the case to- day; stainless steel tanks are the norm. While stainless steel is not affect- ed by fluid contents, aluminum is less resistant and finds it way in small amounts into the juice. A legal limit value does not exist for aluminum con- tent. Nevertheless, the Federal Institute for Risk Assessment has put forth Seite 4 von 5 an official statement in which it asserts that an amount over 8 mg/L is un- desirable for health reasons. CVUA Stuttgart has reported several viola- tions of this guideline due to the presence of higher quantities of aluminum in several fruit juices. In contrast, none of the 90 samples analyzed in 2012 were detected with quantities over the recommended limit. The last aluminum tanks have probably been put out of use. Preservation via heat: does a lot help a lot? The contaminant hydroxymethylfurfural (HMF) comes from a completely different source. This substance occurs mainly as a result of heating sug- ar-containing foods, including fruit juices and nectars. Due to the negative effects of HMF properties on health, high concentrations are undesirable and should, therefore, be limited to the feasibly obtainable value of 20 mg/L in beverages. The distribution of results from the 70 analyzed sam- ples is presented as follows: Quantity of HMF No. Samples Up to 5 mg/L 55 5 mg/L to 10 mg/L 8 10 mg/L to 15 mg/L 4 15 mg/L to 20 mg/L 1 20 mg/L to 25 mg/L 2 This shows that fruit juices and nectars are normally preserved very spar- ingly. Nitrate is absorbed by plants from the soil in quantities depending on the type of fertilizer, and is stored mainly in the roots or the leaves. The fruits, in contrast, take in much less nitrate, so fruit juice is also comparatively low in nitrates. As expected, the 50 samples of juices and nectars con- tained extremely low levels of nitrate under the limit of detection (10 mg/L) – with one surprising exception: one sample contained the high amount of 449 mg/L. The mystery was easily solved, however: the sample was rhu- barb nectar. Rhubarb is a vegetable and vegetable juices normally contain significantly higher levels of nitrate than fruit juices. It’s preserved – does that mean it’s protected from spoilage? Fruit juices and nectars sold in supermarkets are usually not fresh, having been preserved in production. Are they thus protected from spoilage? Several parameters offer analysts the possibility of detecting the begin- nings of spoilage: the fermentation of yeast causes undesirable alcohol Seite 5 von 5 content and lactic acid bacteria ferment sugar into lactic acid. In the guide- lines for fruit juices, therefore, maximum values have been specified, which a properly manufactured product should not violate. As the results of the analyses show, the juices and nectars contained only traces of spoilage parameters, which indicates an appropriate degree of processing of the fruit. Quantity of Alcohol Quantity of Lactic Acid No. Samples Analyzed 90 67 Permitted Quantity 3.0 g/L 0.5 g/L Minimum Value < 0.03 g/L < 0.01 g/L Maximum Value 2.9 g/L 0.48 g/L Median Quantity 0.31 g/L 0.08 g/L Conclusion: The analysis of 90 fruit juices and nectars revealed that the manufacturers do avoid the use of banned additives and that they pre- serve the products sparingly. Contaminants played no role in the beverag- es. In view of the above-described investigations there were no violations of legal requirements. Photo credits: Dr. Braun, CVUA Stuttgart Author: Dr. Gerhard Braun