Australia needs accurate vitamin D food composition data to support public health initiatives. Previously, limitations in analytical methodology have precluded development of a comprehensive database. We used liquid chromatography with triple quadrupole mass spectrometry (LC-QQQ) to analyse 149 composite samples representing 98 foods (primary samples n = 896) in duplicate for vitamin D3, 25-hydroxyvitamin D3 (25(OH)D3), vitamin D2, 25(OH)D2. The greatest concentrations of vitamin D3 were found in canned salmon and a malted chocolate drink powder (fortified); chicken eggs and chicken leg meat contained the most 25(OH)D3. Margarine (fortified) and chocolate contained the greatest concentrations of vitamin D2, with smaller amounts found in various meat products. 25(OH)D2 was detected in various foods, including meats, and was quantitated in lamb liver. These data advance knowledge of dietary vitamin D in Australia and highlight the importance of analysis of these four forms of vitamin D to accurately represent the vitamin D content of food.

Background/Aims: There is a high prevalence of vitamin D deficiency in the Asia Pacific region and other parts of the world. Very few natural foods are a good source of vitamin D, with mushrooms as the only major non-animal source known to date. Upon exposure to ultraviolet (UV) radiation, mushrooms produce high levels of vitamin D, often in excess of 10 μg vitamin D/100 g fresh weight equivalent. This project assessed the efficiency of pulsed UV-radiation to generate D-vitamers in dried white button mush-rooms (Agaricus bisporus). Methods: Freshly picked mushrooms (gills enclosed) were air-dried for 22 h, then exposed to 1–4 s of pulsed UV-radiation before being freeze-dried and analyzed by liquid chromatography triple quadrupole mass spectrometer. The concentrations of vitamins D2, D3, D4, 25-hydroxyvitamin D2, and 25-hydroxyvitamin D3 were measured in triplicate. Results: Vitamin D2 increased in a dose-dependent manner as UV-exposure increased (15, 26, and 32 μg/100 g for 1, 2, and 4 s respectively). A similar dose-dependent effect was seen for vitamin D4 (0.9, 1.7, and 2.6 μg/100 g for 1, 2, and 4 s respectively). Both 25-hy-droxyvitamin D2 and 25-hydroxyvitamin D3 were below the limit of detection (LoD). All D-vitamers were below the LoD in control samples (no UV-exposure). Conclusions: UV-exposed dried mushrooms could be a nutritionally useful source of vitamin D, with 100 g fresh weight (about 3–4 medium mushrooms) providing more than the typical daily requirements for vitamin D (10–20 μg/day, depending on age). Pulsed UV-radiation offers an effective method for commercial production of vitamin D-enhanced dried mushrooms.

The fortification of processed foods including dairy products is increasingly commonplace with phytosterols among many compounds used to improve the nutritional value of food products. It is also increasingly common practice for some dairy cattle feeds to be fortified for their potential to increase phytosterol levels in milk. In this study, a combined, streamlined protocol using acid hydrolysis, saponification and sample clean-up was developed to enable the rapid and reliable measurement of phytosterols. The method was developed with focus on streamlining the overall technique to make it suitable for commercial laboratories, to reduce labor and consumable costs, while maintaining accuracy. A total of 12 different feed types commonly used in the dairy industry were analyzed with the highest and lowest sterol contents found in cotton seed oil and tannin with average phytosterol contents of 256 and <30 mg per 100 g, respectively. With a limit of reporting of 30 mg/kg for individual sterols and a correlation coefficient > 0.99, the method was validated for milk to enable feed comparison studies with respect to the total phytosterol content in raw milk.

Vitamin D has previously been quantified in some plants and algae, particularly in leaves of the Solanaceae family. We measured the vitamin D content of Australian native food plants and Australian-grown edible seaweed. Using liquid chromatography with triple quadrupole mass spectrometry, 13 samples (including leaf, fruit, and seed) were analyzed in duplicate for vitamin D2, vitamin D3, 25-hydroxyvitamin D2, and 25-hydroxyvitamin D3. Five samples contained vitamin D2: raw wattleseed (Acacia victoriae) (0.03 µg/100 g dry weight (DW)); fresh and dried lemon myrtle (Backhousia citriodora) leaves (0.03 and 0.24 µg/100 g DW, respectively); and dried leaves and berries of Tasmanian mountain pepper (Tasmannia lanceolata) (0.67 and 0.05 µg/100 g DW, respectively). Fresh kombu (Lessonia corrugata) contained vitamin D3 (0.01 µg/100 g DW). Detected amounts were low; however, it is possible that exposure to ultraviolet radiation may increase the vitamin D content of plants and algae if vitamin D precursors are present.

Dietary vitamin D may compensate for inadequate sun exposure; however, there have been few investigations into the vitamin D content of Australian foods. We measured vitamin D3 and 25-hydroxyvitamin D3 (25(OH)D3) in four species of white fish (barramundi, basa, hoki and king dory), and chicken eggs (cage and free-range), purchased from five Australian cities. Samples included local, imported and wild-caught fish, and eggs of varying size from producers with a range of hen stocking densities. Raw and cooked samples were analysed using high performance liquid chromatography with photodiode array. Limits of reporting were 0.2 and 0.1 μg/100 g for vitamin D3 and 25(OH)D3, respectively. The vitamin D3 content of cooked white fish ranged from <0.1 to 2.3 μg/100 g, and the 25(OH)D3 content ranged from 0.3 to 0.7 μg/100 g. The vitamin D3 content of cooked cage eggs ranged from 0.4 to 0.8 μg/100 g, and the 25(OH)D3 content ranged from 0.4 to 1.2 μg/100 g. The vitamin D3 content of cooked free-range eggs ranged from 0.3 to 2.2 μg/100 g, and the 25(OH)D3 content ranged from 0.5 to 0.8 μg/100 g. If, as has been suggested, 25(OH)D3 has five times greater bioactivity than vitamin D3, one cooked serve (100 g) of white fish, and one cooked serve of cage or free-range eggs (120 g) may provide 50% or 100%, respectively, of the current guidelines for the adequate intake of vitamin D (5 µg) for Australians aged 1–50 years.

Phytosterols are naturally occurring compounds found in plants and their consumption is claimed to lower blood cholesterol levels and reduce the risk of cardiovascular disease. The recent growth in the fortification of foods with phytosterols has led to an increasing requirement and demand by the food industry for rapid, economical, accurate and reliable techniques for phytosterol quantification. The ability to determine accurate levels of such additives is critical to ensure that foods are not under- or over-fortified and that the levels conform to the available standards. Methods of phytosterol analysis are commonly modified to streamline the extraction and quantification process with most analyses performed using gas chromatography coupled with flame ionization detection. This reference module reviews the current methods for phytosterol quantification in fortified foods with an emphasis on method optimization and streamlining.

A novel method for the measurement of total phytosterols in fortified food was developed and tested using gas chromatography with flame ionization detection. Unlike existing methods, this technique is capable of simultaneously extracting sterols during saponification thus significantly reducing extraction time and cost. The rapid method is suitable for sterol determination in a range of complex fortified foods including milk, cheese, fat spreads, oils and meat. The main enhancements of this new method include accuracy and precision, robustness, cost effectiveness and labour/ time efficiencies. To achieve these advantages, quantification and the critical aspects of saponification were investigated and optimised. The final method demonstrated spiked recoveries in multiple matrices at 85-110% with a relative standard deviation of 1.9% and measurement uncertainty value of 10%. (C) 2016 Elsevier Ltd. All rights reserved.

OBJECTIVES:To assess the potential dietary supply of vitamin D to Australian adults by application of new data for Australian primary foods of animal origin.METHODS:New published analytical data on the vitamin D contents of Australian primary foods from animal products were obtained and assessed for reliability. Using food consumption data from Australian population dietary surveys for 1995 and 2011-2013, estimates were made of the likely average daily intakes of vitamin D equivalents from these sources by Australian adults.RESULTS:Meats, chicken, fish, eggs and dairy produce may alone have contributed about 4.2 μg vitamin D equivalents per day to average Australian diets of adults >18 years in 1995 and 4.3 μg in 2011-2013.CONCLUSIONS:Dietary vitamin D intake in Australia is likely to be higher than previously estimated because new data from improved analytical methods reveal the contributions to vitamin D supply from foods of animal origin. Absence of reliable vitamin D data for milk and milk products, and the gaps in vitamin D data for many commonly consumed seafood, poultry, eggs and processed animal products greatly limit estimation of dietary vitamin D intakes by Australians.

This paper reports a method for the rapid, sensitive and simultaneous analysis of vitamin D (Vit D) and 25-hydroxyvitamin D (25OH-Vit D) in meats. Samples were saponified and underwent solid phase extraction with analysis by normal phase liquid chromatography (LC) with ion trap mass spectroscopy (IT-MS), using positive polarity atmospheric pressure chemical ionisation (APCI). Limits of detection (LOD) and quantification (LOQ) for Vit D and 25OH-Vit D were 0.03 and 0.05μg/100g respectively. Deuterium labelled Vit D and 25OH-Vit D internal standards were added as surrogates prior to saponification, correcting for extraction inefficiencies and potential MS matrix enhancement or suppression effects. Recoveries using internal/surrogate standard correction ranged from 80% to 100% for all vitamers. Measurement uncertainty ranged from 6% to 15% for all vitamers in this method. This process required only 7.5g of sample per extraction and a batch of 28 extractions could be completed in six hours.

There is little information on the vitamin D content of Australian red meat or on the possible influence of latitude on this content. To determine the content of vitamin D3 and 25-hydroxy-vitamin D3 (25OHD3), lamb and beef were analysed from 34° S with LC–IT-MS. To investigate the possible influence of latitude on vitamin D in meat, the lean meat and fat from five cuts of beef were analysed from 17° S and 41° S. Lamb contained 0.10 μg vitamin D3/100 g and 0.20 μg 25OHD3/100 g lean meat, while beef contained 0.12 μg vitamin D3 and 0.27 μg 25OHD3/100 g (lean meat). Latitude had no effect on the vitamin D3 (P = 0.21) or 25OHD3 (P = 0.29) content of lean beef, but fat from cattle in the 17° S latitude group contained significantly higher (P < 0.01) concentrations of vitamin D3 than fat from the 41° S group of cattle.