In early 2017 FSANZ undertook a small analytical program to update and expand our food composition data holdings. Seventeen commonly consumed foods were selected for analysis of selected nutrients for which we hold no data, or where the data we do hold is out-dated and no longer reflects the products available for consumption.
The range of nutrients analysed differed for each food depending on what data was available, the quality of the data, whether the nutrient was likely to be present in the food and the impact the consumption of the food may have on population intakes of that nutrient.
Sampling
A total of eight purchases of each food were made across the Australian Capital Territory, Queensland, Victoria, South Australia and Western Australia to provide a range of brands and production locations for fresh foods. Multiple items were included in one purchase for some foods (i.e. one purchase of carrots included four individual carrots) to ensure an appropriate sample weight was obtained. Sampling was carried out by FSANZ and the National Measurement Institute (NMI). All food purchases were made within capital city metropolitan areas at a retail outlet representing the buying habits of the majority of the community, including supermarkets, health food stores and fresh fruit and vegetable stores. If more than one sample of the same brand was purchased, different batch codes or use by dates were selected.
The complete list of foods selected for analysis is available in Table 1.
Table 1: Foods selected for analysis
| Foods | No. of samples purchased (total no. of items purchased) |
No. of brands / varieties |
|---|---|---|
| Flour, white, wheat, plain | 8 (8) | 4 |
| Flour, white, wheat, self-raising | 8 (9) | 4 |
| Flour, white, bread making | 8 (8) | 4 |
| Flour, white, gluten free | 8 (8) | 5 |
| Flour, corn | 8 (13) | 2 |
| Bulgur, uncooked | 8 (10) | 6 |
| Psyllium, uncooked | 8 (12) | 4 |
| Wheat germ, uncooked | 8 (13) | 5 |
| Cheese, fetta, regular fat | 8 (20) | 7 |
| Cheese, ricotta, regular fat | 8 (9) | 5 |
| Coconut cream, regular fat | 8 (14) | 6 |
| Coconut milk, regular fat | 8 (14) | 8 |
| Sultanas | 8 (10) | 5 |
| Cauliflower, fresh, raw | 8 (10) | 4 |
| Carrot, fresh, peeled, microwaved | 8 (56) | 5 |
| Corn, fresh, on the cob, raw | 8 (75) | 5 |
| Tomato, canned | 8 (13) | 7 |
Nutrients analysed included moisture, fat, protein, starch, individual sugars, total dietary fibre, ash, organic acids, carotenes, thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, cobalamin, total folates, folic acid, vitamin C, alpha-tocopherol, aluminium, arsenic, cadmium, calcium, chromium, copper, iodine, iron, lead, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc, tryptophan and fatty acids. Each food was analysed for a different combination of nutrients based on likely content and data requirements.
Preparation and analysis
The samples were delivered by hand or sent by courier to NMI. Once received, the samples were photographed and copies were provided to FSANZ for approval prior to analysis.
NMI prepared samples according to the sample preparation procedures provided by FSANZ. Each sample was weighed (before and after preparation where appropriate), homogenised and either prepared to be analysed individually or combined to form one composite sample, depending on the nutrient to be analysed.
NMI conducted the analyses at their Melbourne laboratories using methods of analysis that have been accredited by the National Association of Testing Authorities.
Results
FSANZ validated the results using our existing analytical data, food labels (ingredient lists and nutrition information panels) where available and data from international food composition databases for similar foods.
The majority of results were consistent with previous findings. A small number of analytes in some foods showed levels outside the expected range. These food samples were reanalysed by the laboratory, and in some cases by a second laboratory, and all results were verified and accepted.
Some results worth noting include:
- Folic acid was variable among the samples of bread-making flour. Of the seven samples which were labelled as containing added folic acid, only three returned values consistent with requirements in the Food Standards Code.
- Higher than expected levels of aluminium were recorded in self-raising flour compared to plain flour (240 vs 53 µg/100 g). This could be due to natural variation and the use of assorted leavening agents.
- The sum of proximates for sultanas was very low (~83 g/100 g). This is likely due to the presence of complex sugars which have not been analysed as part of this program.
For the complete set of results generated from this program refer to:
Conclusion
The results of this analytical program have filled some important data gaps and given us an improved level of confidence about the composition of these foods which contribute to population nutrient intakes. The results will also feed into future releases of the FSANZ reference database: the Australian Food Composition Database (formerly called NUTTAB).