The study aimed to compare the nutritional composition of commercial and home-made orange juices with a fruit content of 100%, i.e., without dilution with water and without addition of sugars or any other sweeteners. Orange juice samples (n = 12 for both types of juice) were representative of the French market and of French consumers’ habits as determined by a consumer survey. The results showed that both types of juices contained the same concentrations in total sugars and polyphenols and had low levels of dietary fiber (P > 0.05 for all parameters). Commercial orange juice contained less vitamin C (P = 0.035) and folate (P = 0.002) than home-made juice (15% and 27% less, respectively), probably owing to the vitamin degradation that may occur during industrial production (e.g., during pasteurization) and storage of commercial orange juice. The observed differences were of relatively small magnitude overall, however, and within the expected ranges for vitamin loss due to pasteurization and storage at ambient temperature. Indeed, commercial orange juice contained 85% of the vitamin C concentration measured in home-made juice, showing that vitamin C was well preserved in commercial juice. Another study with a larger number of samples would be needed to confirm these observations.
Fruit juices are very lightly processed foods that are governed by a specific regulation within the European Union: Council Directive 2001/112/EC, which has been transposed into French law by Decree 2003-838 and amended by Directive 2012/12/EU. This regulation defines three main types of products, depending on the fruit content and process: “fruit juice”, “fruit juice from concentrate” and “fruit nectar”. Fruit juice is obtained by mechanical extraction (squeezing) of fruits harvested at maturity, followed by pasteurization. Fruit juice from concentrate is obtained in the same way except that the juice is concentrated through evaporation of natural water content. The juice is then restored by adding the same amount of water as was extracted from that juice during the concentration process. The concentration step is used to facilitate storage and transportation, and improve the environmental impact of the product. Fruit nectar is made by adding water to fruit juice or fruit purée, with or without sugar or artificial sweeteners. The minimal fruit content in fruit nectar should be 25% - 50%, depending on the type of fruit.
Orange juice (OJ) is the most consumed fruit juice in Europe and around the world [
OJ contains substantial amounts of several micronutrients such as vitamin C, folate and polyphenols (e.g., hesperidin which is a flavanone) [
Some steps of the process used for the industrial production of OJ are known to impact its nutritional composition, especially for vitamin C [
L-ascorbic acid (Sigma A5960), gallic acid monohydrate (Sigma 27645) and Folin-Ciocalteu reagent (Sigma F9252) were purchased from Sigma Chemical Co. (St. Louis, MO, USA). Total dietary fiber assay kit (K-TDFR), protease (Subtilisin A from Bacillus licheniformis) (E-BSPRT), α-amylase (from Bacillus licheniformis) (E-BLAAM) and amyloglucosidase (from Aspergillus niger) (E-AMGDF) were purchased from Megazyme International Ireland (Bray, Co. Wicklow, Ireland). The Sucrose/D-Glucose/D-Fructose kit [Roche (previously Boehringer Mannheim) 10 716 260 035] was purchased from R-Biopharm France (Saint Didier au Mont d’Or, France). Lactobacillus casei ATCC 7469 (L. rhamnosus) was purchased from Culture Collection, University of Göteborg (product no. CCUG 21452) and free folic acid-casei medium (Difco 282210) was purchased from Becton Dickinson (BD) (Franklin Lakes, NJ, USA). All chemical reagents used in the experiments were of analytical grade.
A consumer survey was performed between March 5 and March 10, 2014 (CSA institute), in a sample of 1006 adults (481 men, 525 women) representative of the French adult population. Participants completed an online questionnaire with the aim to describe their usual consumption of fruit juices and their perception about fruit juices. The questionnaire included ten questions related to preparation and consumption of home-made fruit juices.
The aim was to compare the nutritional composition of commercial and home-made OJ with a fruit content of 100%, i.e., without dilution with water and without addition of sugars or any other sweeteners.
Commercial orange juice: The aim was to create a sample that would be representative of the OJ market in France (
Home-made orange juice: The aim was to create a sample that would be representative of the actual practices of French consumers regarding home-made OJ. For that purpose, answers from questions related to preparation and consumption of home-made juices obtained in the consumer survey described in Section 2.2 were used to define the protocol for preparation of home-made OJ (types of oranges, mode of squeezing). Oranges were bought in July 2014 and OJ samples were prepared according to the indications given by the result of the consumer survey (see Section 3.2. below). All chemical analyses were performed just after preparation of the OJ.
Sugar concentrations in OJ were measured according to methods published by the International Federation of Fruit Juice Producers (IFU). More precisely, glucose and fructose concentrations were measured according to method IFUMA55 [
Vitamin C concentration in OJ was measured by high performance liquid chromatography (HPLC) according to NF V03-135 [
Total folate concentration in OJ was measured by a microbiological assay using Lactobacillus casei ATCC 7469 (L. rhamnosus) and free folic acid-casei medium according to AOAC method 2004.05 [
Concentrations of total polyphenols were analyzed by a colorimetric assay using Folin-Ciocalteu phenol reagent (F?C reagent) according to method ISO-14502-1 [
Total dietary fiber was measured according to AOAC method 985.29 [
Titratable acidity was measured according to method IFUMA03 [
density meter (Anton Paar DMA 5000). All determinations were done once and the result uncertainty was U = 0.00020. The corresponding Brix was calculated by using the tables relating Brix and Relative Density described in method IFUMA08 [
All the analyses described above have been performed by a laboratory with ISO/IEC 17025 accreditation for the mentioned assays, except for the determination of total polyphenols. In accordance with the COFRAC (French Committee of Accreditation) specifications (LAB GTA25), a routine repeatability assay is performed every month for each analysis and before each measurement (a minimum of 95% of the results must be repeatable). Furthermore, each analytical session is internally verified with a control chart (internal or external reference material), and the laboratory takes part in a proficiency test every month.
All results are presented as arithmetic means ± SD. The nutritional composition of the two samples of OJ (commercial and home-made OJ) were compared using the Wilcoxon-Mann-Whitney rank sum test. Statistical analyses were performed with R (2.13.0). Statistical significance was set at P < 0.05.
Results from the consumer survey showed that 93% of the questioned consumers who prepared home-made OJ bought specific oranges for this purpose (i.e., oranges labeled as “intended for juice” in the store). Most of the consumers (49%) used two oranges to make one serving of OJ (31%used ≥ three oranges, 20% used one orange) and the preferred method for squeezing was manual or electric citrus juicer (94%). Ninety-five per cent of the subjects consumed the juice less than 15 min after it was prepared, and 71% kept it at ambient temperature before consumption. The average volume of consumed home-made juice was 170 ml (77% consumed between 100 and 200 ml; 12% consumed ≥ 250 ml) and 95% of the subjects consumed home-made juice without addition of sugar or water. The sample of home-made OJ (n = 12) used in our study was created on the basis of these results (
As shown in
for sucrose (approx. 10%). Differences in maturity, variety and/or origin between the oranges used to make home-made OJ and commercial OJ may explain those small variations. For instance, all the oranges used for home-made OJ originated from Spain while those used to make commercial OJ were mostly from Brazil. Furthermore, and as illustrated in
Results for relative density and degree Brix reflected those obtained with total sugars since no significant differences were observed between the two types of OJ (relative density: 1.05 for both types of OJ; degree Brix: 11.2 ± 0.4 and 11.1 ± 0.9 for commercial and home-made OJ, respectively). Titratable acidity (pH 8.1) was significantly higher for home-made OJ (0.965 ± 0.188 g/100mL, expressed in citric acid) as compared with commercial OJ (0.739 ± 0.0596 g/100mL) (P = 0.001). Once again, differences in orange origin may explain this observation, oranges from Spain being generally more acidic than oranges from Brazil.
Commercial OJ contained significantly less vitamin C (−15% approx.) and folate (−27%, approx.) than home- made OJ (vitamin C: 40.5 ± 10.1 mg/100mL vs 47.8 ± 8.59 mg/100 L, respectively, P = 0.035,
Concentrations of total polyphenols were similar between the two types of OJ (63.3 ± 5.85mg/100mL vs 62.9 ± 5.94 mg/100mL, for the commercial and home-made OJ, respectively, P = 0.95,
Finally, both commercial and home-made OJ contained low levels of dietary fiber, which were below the method’s limit of detection (i.e., <0.5g/100mL). Here, it should be specified that orange pulps were not reincorporated into the juice after squeezing during the preparation of the home-made OJ, and that 92% of the commercial OJ did not contain added orange pulps (11 references out of 12).
Our study had some limitations that should be acknowledged. Although the sample size was sufficient to perform statistical comparisons between analytical data, our conclusions should be considered with caution because of the small number of analyzed samples, and results would need to be confirmed with another larger study. In particular, no conclusions could be drawn regarding the impact of the individual factors that could explain some of the result variability (e.g., orange variety and origin, types of packaging and storage temperature before opening for commercial OJ, mode of squeezing for home-made OJ). All oranges used to make home-made OJ were from the same origin (Spain) and of the same variety (Valencia), which therefore precluded any variability in these factors being introduced within the sample of home-made OJ. This was because fruit collections were all performed at the same time (July), and at that time of the year most oranges ‘intended to make juice’ that are available in French retail stores are of this variety and origin. Although Valencia is among the varieties most often used for home juicing in France, results for home-made OJ may need to be confirmed with further analyses with other types of oranges. Finally, although concentration of total polyphenols is almost equivalent to hesperidin concentration in OJ (since hesperidin is the dominant polyphenol), it would have been interesting to measure the flavanone glycosides (especially hesperidin) in our OJ samples instead of total polyphenols.
Our work had also several strengths. To our knowledge, it was the first study to compare the nutritional composition between home-made OJ and commercially available OJ, with a sample of products which was representative of the actual French market. Besides, the sample of home-made OJ was built to reflect the usual attitudes and practices of French consumers, as recorded from a consumer survey. These characteristics made our work original as compared with previous studies in this area, which did not consider commercially available OJ or home-made OJ prepared following usual consumer’s practices (e.g., [
This study compared the nutritional composition of two samples of commercial and home-made OJ, which were representative of the French OJ market and of French consumers’ habits. It showed that both types of OJ contained the same concentrations in total sugars and total polyphenols. Home-made OJ contained a very low amount of dietary fiber, as did commercial OJ. Vitamin C and folate concentrations were lower in commercial OJ than in home-made OJ, probably because of the vitamin degradation that may occur during industrial production (e.g., during pasteurization) and storage of commercial OJ. The observed differences were of relatively small magnitude, however, and within the expected ranges for vitamin loss due to pasteurization and storage at ambient temperature. Indeed, commercial OJ contained 85% of the vitamin C concentration measured in home- made OJ, showing that vitamin C was well preserved in commercial OJ. This is consistent with the fact that fruit juices, and OJ in particular, are important contributors to vitamin C intakes within the French population: being the primary contributor in children and the second most important contributor, after whole fruits, in adults [
The authors wish to thank Petra Roberts who provided language help and reviewed the final version of the manuscript.
LB is employee of Qualijus (Institut Professionnel pour la Qualité des Jus de Fruits). ACR and VB have received fees for technical and scientific consulting from the fruit juices professional associations.
Funding for this study has been provided by Qualijus. The funder did not have any role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
Aurelie Chanson-Rolle,Veronique Braesco,Julien Chupin,Laurence Bouillot, (2016) Nutritional Composition of Orange Juice: A Comparative Study between French Commercial and Home-Made Juices. Food and Nutrition Sciences,07,252-261. doi: 10.4236/fns.2016.74027
AFNOR: Association française de normalisation.
AIJN: European Fruit Juice Association.
COFRAC: Comité français d’accréditation.
CREDOC: Centre de recherche pour l’étude et l’observation des conditions de vie.
IFU: International federation of fruit juice producers.
OJ: Orange juice.