Background
In 2022-23 Food Standards Australia New Zealand (FSANZ) undertook an analytical program to update and expand our food composition data holdings. Twelve foods were selected for nutrient analysis for which we hold no data, or the data we do hold is out-dated and may no longer reflect the products available for consumption.
The nutrients selected to be analysed differed for each food depending on what data was available, the quality of the data, and whether the nutrient was likely to be present in the food.
Sampling
Eight samples were purchased for each food. The foods were sampled across five states and territories (Australian Capital Territory, Queensland, Victoria, South Australia and Western Australia) to provide a range of production locations. For some samples, multiple items were required to ensure an appropriate sample weight was obtained (i.e. one sample of coated deep-fried chicken included 3-6 individual pieces).
Sampling was carried out by FSANZ and the National Measurement Institute (NMI). All food purchases were made within capital city and metropolitan areas to represent the buying habits of the majority of the community. Food purchases were made at a range of retail outlets including supermarkets, grocers, butcheries, bakeries, restaurants, and takeaway/fast-food outlets. If more than one sample of the same brand was purchased, different batch codes or use by dates were selected where possible.
The complete list of foods selected for analysis is available in Table 1.
Table 1: Foods analysed in the 2022-23 key foods analytical program
| Foods | No. of samples purchased (no. of items purchased*) |
No. of brands/varieties |
|---|---|---|
| Bread products | ||
| Bread, brioche | 8 (12) | 5 |
| Crumpet, white, toasted | 8 (8) | 3 |
| Chocolate bars | ||
| Bar, wafer & cream layers, chocolate-coated (Kit Kat) | 8 (30) | 2 |
| Bar, nougat & caramel centre, milk chocolate-coated (Mars Bar) | 8 (36) | 2 |
| Dairy & dairy alternatives | ||
| Cheese, dairy-free, hard | 8 (8) | 5 |
| Yoghurt, sheep | 8 (8) | 2 |
| Mixed dishes | ||
| Beef, hamburger patty/rissole, raw | 8 (9) | 4 |
| Cheeseburger, fast food | 8 (15) | 3 |
| Chicken, coated, deep fried, fast food | 8 (43) | 4 |
| Shark, battered, deep fried, takeaway outlet | 8 (15) | - |
| Fried rice, commercial | 8 (8) | - |
| Other | ||
| Beverage base, chocolate flavour, added vitamins & minerals (Milo) | 8 (8) | 1 |
*In some instances, multiple items must be purchased to reach the required weight of 200 g edible portion per sample.
Preparation and analysis
The samples were delivered 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 combined to form one composite sample. Nutrients analysed in this program are listed in Table 2.
NMI conducted the majority of analyses at their Melbourne laboratories. Starch and total dietary fibre were conducted by AEGIC at their Sydney laboratory. Vitamin B12, total folates and folic acid were conducted by PathWest at their Perth laboratory. Methods of analysis used have been accredited by the National Association of Testing Authorities.
Table 2: Nutrients analysed in the 2022-23 key foods program
| Proximates | Vitamins | Minerals | Other |
|---|---|---|---|
| Moisture Total dietary fibre Starch Total fat Protein Sugar profile Ash Organic acids |
Retinol Carotenes (α and β) Thiamin (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Pyridoxine (B6) Total folate Folic acid Cobalamin (B12) Ascorbic acid (C) Tocopherols (α, β, γ and δ) |
Aluminium Arsenic Calcium Copper Iodine Iron Lead Magnesium Manganese Mercury* Molybdenum Phosphorus Potassium Selenium Sodium Zinc |
Fatty acid profile Cholesterol Caffeine Tryptophan |
*Mercury was analysed exclusively in shark, battered, deep fried, takeaway outlet.
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. Values for a small number of analytes in some foods were outside the expected range.
Analysis of total arsenic in battered deep fried shark returned a value of 1,500 µg/100 g. Previous results for similar samples ranged from 88 µg/100 g in frozen fish portions to 290 µg/100 g in prawns (FSANZ, 2019). A maximum level (ML) for inorganic arsenic in fish of 2 mg/kg (200 ug/100 g) is set within Schedule 19 of the Australia New Zealand Food Standards Code. Inorganic arsenic is known to be the toxic form of the chemical while organic arsenic is not harmful when consumed by humans. A re-analysis of total arsenic was requested, in addition to the analysis of inorganic arsenic. The re-analysis of total arsenic returned a value of 1,400 µg/100 g, confirming the original result. The analysis of inorganic arsenic returned a value below the limit of reporting (<1 µg/100 g). This confirmed that the predominant form of arsenic in the battered, deep fried shark sample is organic arsenic. This finding supports those of the 25th Australian Total Diet Study (ATDS) which reported seafood as the major contributor to dietary exposure of total arsenic for all age groups assessed (FSANZ, 2019).
Analysis of iodine and thiamin (B1) in coated deep fried chicken returned values of 82 ug/100g and 0.58 mg/100g, respectively. These were above the expected range for an unfortified product so were re-analysed. The re-analysis of both components returned values which confirmed the original results. Considering the above, it was theorised that the coating used in the samples could have contained bread-making flour which was fortified with iodised salt and thiamin. In future analyses of similar food products, FSANZ notes that the analysis of folic acid should also be considered, due to its use as a fortificant in bread-making flour.
Remaining queries were followed up with the lab until all results were accepted. For the complete set of results generated from this program refer to the below 2022-23 key food analytical program data table.
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 FSANZ published databases, including the Australian Food Composition Database and future national nutrition survey databases (AUSNUT).
References
- FSANZ (2019) 25th Australian Total Diet Study. Food Standards Australia New Zealand, Canberra. Accessed on 12 December 2022